The scenario describes a patient undergoing a complex surgical procedure involving the repair of a comminuted fracture of the distal tibia with associated disruption of the syndesmosis. The surgeon performs an open reduction and internal fixation (ORIF) of the tibia, utilizing a plate and screws. To stabilize the syndesmosis, a syndesmotic screw is inserted. The documentation also indicates the application of an external fixator for additional stability during the initial healing phase. For coding this scenario, we need to identify the primary procedure and any secondary procedures or services that are separately reportable. The ORIF of the distal tibia with internal fixation is the principal procedure. The insertion of a syndesmotic screw is an integral part of stabilizing the ankle joint in conjunction with the tibial fracture fixation, and therefore, it is typically bundled into the ORIF code for the tibia unless specific payer guidelines or CPT instructions dictate otherwise. However, the application of an external fixator, even if temporary, represents a distinct procedure that provides stabilization and management of the fracture. Based on CPT guidelines for fracture management, reporting an external fixator in conjunction with an internal fixation for the same fracture site is permissible when the external fixator is applied to provide additional stability or manage the fracture in a distinct manner. The operative report clearly states the application of an external fixator. Therefore, the coding should reflect both the internal fixation of the tibia and the application of the external fixator. The correct CPT code for the open reduction and internal fixation of a comminuted fracture of the distal tibia would be selected based on the specific anatomical location and complexity. For the external fixation, a separate CPT code for the application of an external fixator to the tibia and fibula would be used. The combination of these distinct services accurately reflects the surgical intervention. Let’s assume the appropriate CPT code for ORIF of the distal tibia is 27759 (Open treatment of distal tibia fracture [e.g., Pott’s fracture] [e.g., bimalleolar, trimalleolar] with or without fixation and with or without manipulation). The appropriate CPT code for the application of an external fixator to the tibia and fibula would be 20700 (Application of external fixation to the tibia and fibula). When both procedures are performed, modifier -51 (Multiple Procedures) might be considered for the secondary procedure, or specific CPT guidelines might indicate that no modifier is needed if the services are distinct and separately reportable. However, for the purpose of this question, we are focused on identifying the correct *procedures* to be coded. The question asks for the procedures performed. The core procedures are the internal fixation of the tibia and the application of the external fixator. Therefore, the correct identification of the procedures performed is the open reduction and internal fixation of the distal tibia and the application of an external fixator to the tibia and fibula.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained implant. The primary procedure is a revision of a total knee arthroplasty. The documentation indicates the use of a constrained prosthesis due to ligamentous instability, which is a key factor in selecting the appropriate CPT code. The bone loss necessitates bone grafting, specifically an allograft, to reconstruct the deficient bone stock. The complexity of the revision, the use of a constrained implant, and the allograft all contribute to the coding decision. The correct CPT code for a revision of a total knee arthroplasty with a constrained prosthesis and allograft for bone grafting is 27487. This code specifically covers the revision of a total knee arthroplasty with a constrained prosthesis and includes the use of bone graft. The scenario clearly outlines these components: revision TKA, constrained implant, and allograft for bone grafting. Other codes would be inappropriate because they do not encompass all these elements. For instance, codes for primary TKA, or revisions without constrained implants or bone grafting, would not accurately reflect the services provided. The use of an allograft is integral to the complexity and management of the bone loss in this revision, making 27487 the most precise and comprehensive code.

The scenario involves a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained prosthesis. The primary procedure is a revision TKA, which is coded using the Current Procedural Terminology (CPT) system. The complexity arises from the bone loss, necessitating bone grafting. Bone grafting in conjunction with a joint replacement is typically reported with specific add-on codes. For a revision TKA, the base code would be from the range 27486-27487 (Revision of total knee arthroplasty, with or without allograft; with proximal tibial articular surface replacement, with or without anterior tibial plateau augmentation, or with distal femoral augmentation, or with patellar augmentation; or with total tibial resurfacing, with or without augmentation). Given the complexity and likely need for augmentation, 27487 is a strong candidate for the primary procedure. The bone graft, if autograft, would be coded separately. However, if allograft is used, it is often bundled or has specific add-on codes. The question specifies “allograft,” and the CPT manual provides add-on codes for allograft use in joint arthroplasty. Specifically, for a revision TKA with allograft, the add-on code for the allograft component is 27488 (Allograft for structural support of proximal tibial articular surface replacement, revision of total knee arthroplasty). The scenario also mentions “constrained prosthesis,” which is a feature of the implant used to address instability, but it does not typically have a separate CPT code; it’s a descriptor of the implant used within the primary procedure code. Therefore, the correct coding would involve the base code for revision TKA with augmentation and the add-on code for the allograft. Considering the options, the combination of a revision TKA code and an allograft code is essential. The most appropriate combination reflecting a revision TKA with allograft for bone loss would be 27487 (Revision of total knee arthroplasty, with or without allograft; with total tibial resurfacing, with or without augmentation) and 27488 (Allograft for structural support of proximal tibial articular surface replacement, revision of total knee arthroplasty). This accurately captures the complexity of the revision and the use of allograft for bone support, aligning with the advanced coding principles taught at Certified Orthopaedic Surgery Coder (COSC) University, which emphasizes precise coding for complex reconstructive procedures.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a distal femoral osteotomy to facilitate implant removal and preparation, followed by the insertion of a cemented, highly constrained posterior-stabilized revision implant with augments to address the bone deficit. The question asks for the most appropriate ICD-10-CM code for the underlying condition necessitating this extensive surgical intervention. To determine the correct ICD-10-CM code, we must analyze the provided clinical information. The patient has a history of a failed total knee arthroplasty (TKA) requiring revision. The failure is attributed to “aseptic loosening of the prosthetic components” and “significant bone loss.” The revision procedure involves a constrained implant, indicating severe instability. The distal femoral osteotomy suggests a challenging revision due to scar tissue or malalignment. Let’s break down the coding considerations: 1. **Failed Arthroplasty:** The primary reason for the surgery is the failure of the previous TKA. ICD-10-CM codes for failed arthroplasty are found in Chapter 19 (Injury, poisoning and certain other consequences of external causes) under the subcategory T84.5- (Mechanical complication of internal joint prosthesis). Specifically, T84.51XA (Mechanical complication of internal right knee prosthesis, initial encounter) or T84.52XA (Mechanical complication of internal left knee prosthesis, initial encounter) would be considered if the failure was purely mechanical. However, “aseptic loosening” is a specific type of mechanical complication. 2. **Aseptic Loosening:** ICD-10-CM provides specific codes for mechanical complications of internal prosthetic devices, implants and grafts. For aseptic loosening of a knee prosthesis, the appropriate code is T84.51XA (Mechanical complication of internal right knee prosthesis, initial encounter) or T84.52XA (Mechanical complication of internal left knee prosthesis, initial encounter). The “X” in these codes is a placeholder for a seventh character, which would indicate the encounter type (e.g., A for initial encounter, D for subsequent encounter, S for sequela). Assuming this is the initial encounter for the revision surgery, the seventh character would be ‘A’. 3. **Bone Loss:** While bone loss is a significant factor in the complexity of the surgery, it is often a consequence of the aseptic loosening or a separate condition. ICD-10-CM codes for bone loss are typically found in Chapter 13 (Diseases of the musculoskeletal system and connective tissue), such as M89.89X (Other specified bone diseases, other site) or specific codes related to osteomyelitis if infection were present. However, in the context of a failed prosthesis, the *reason* for the failure (aseptic loosening) is usually coded first, and the bone loss is considered a manifestation or complication of that failure. 4. **Instability:** The need for a “highly constrained” implant directly implies significant joint instability. While instability can be coded separately (e.g., M25.56- for pain in knee, or codes related to ligamentous laxity), in the context of a failed arthroplasty, the instability is a direct result of the aseptic loosening. Considering the primary driver for the revision surgery is the aseptic loosening of the prosthetic components, the most accurate ICD-10-CM code reflects this complication. The scenario specifies “aseptic loosening of the prosthetic components” as the reason for the revision. Therefore, the code for mechanical complication of the internal knee prosthesis due to aseptic loosening is the most appropriate primary diagnosis. The correct approach is to identify the specific complication of the internal prosthetic device. Aseptic loosening is a well-defined mechanical complication. The ICD-10-CM system has specific codes for these complications. For a knee prosthesis, the codes are within the T84 category. The specific code for mechanical complication of an internal knee prosthesis, with aseptic loosening as the underlying cause, is T84.52XA (assuming the left knee, as is common in many examples, though the question doesn’t specify left or right, so we’ll use the general structure). The seventh character ‘A’ signifies an initial encounter for the management of this complication. The extensive nature of the surgery (osteotomy, constrained implant, augments) supports the severity indicated by this code. The final answer is T84.52XA.

The scenario involves a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon documents the procedure using specific CPT codes. To determine the correct coding, we must analyze the components of the procedure and apply the appropriate CPT codes for revision of a total knee arthroplasty and the use of a constrained implant. First, identify the primary procedure: revision of a total knee arthroplasty. The CPT code for this is 27487 (Revision of total knee arthroplasty, with or without allograft; femoral, tibial, and patellar components). Next, consider the additional complexity introduced by the significant bone loss requiring a constrained prosthesis. The use of a constrained prosthesis is typically an add-on service that reflects the increased complexity and materials used. The CPT code for this is 27488 (Revision of total knee arthroplasty, with or without allograft; femoral, tibial, and patellar components; with bone-graft (autograft, allograft), or prosthetic bone substitute, or prosthetic component for augmentation or reconstruction of bone). However, the question specifies a “constrained prosthesis,” which is directly addressed by a separate add-on code when used with revision arthroplasty. The appropriate add-on code for the use of a constrained prosthesis in a revision total knee arthroplasty is 27489 (Revision of total knee arthroplasty, with or without allograft; femoral, tibial, and patellar components; with implantation of a constrained prosthesis). Therefore, the correct coding would involve the primary code for the revision and the add-on code for the constrained prosthesis. The combination of 27487 and 27489 accurately reflects the documented procedure. The explanation focuses on the distinct components of the surgical intervention and their corresponding CPT codes, emphasizing the necessity of reporting both the revision and the specialized implant type. This aligns with the Certified Orthopaedic Surgery Coder (COSC) University’s emphasis on precise and comprehensive coding for complex orthopaedic procedures, ensuring accurate reimbursement and data collection for quality assessment and research. Understanding the nuances of revision codes and add-on services for specialized implants is crucial for coders to accurately represent the patient’s care and the surgeon’s work.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss, necessitating the use of a constrained prosthesis and allograft. The primary procedure is a revision of a total knee arthroplasty. The complexity arises from the bone loss, which requires augmentation. The use of a constrained prosthesis indicates a higher level of instability or bone deficiency, often requiring specific coding considerations. The allograft is a biological implant used to reconstruct bone defects. When coding for revision arthroplasty, the base procedure is the revision of the specific joint. In this case, it’s a revision of the knee. The complexity of the revision, particularly when involving significant bone loss and the use of specialized implants like constrained prostheses, often necessitates additional codes or modifiers to accurately reflect the work performed. The use of allograft for bone reconstruction is a significant component of the procedure and requires separate identification. Considering the CPT coding system, revision arthroplasties are distinct from primary arthroplasties. Codes for revision procedures typically reflect the complexity and the components revised (e.g., femoral, tibial, patellar). The addition of bone graft, especially allograft, is a separately reportable service when it’s a substantial part of the reconstruction. The specific CPT codes for knee arthroplasty revisions would be identified, and then the code for the allograft would be appended. For example, a revision of the knee joint would be coded, and then a code for the use of allograft for bone grafting in the knee would be added. The use of a constrained prosthesis is often inherent in the revision code for severe instability or bone loss, or may require a specific modifier if not explicitly captured. The correct approach involves identifying the primary revision procedure code for the total knee arthroplasty. Then, the code for the use of allograft for bone grafting in the knee is added. Modifiers may be necessary to further specify the encounter, such as the location or laterality. The combination of these elements accurately represents the surgical service provided. The correct answer is the combination of the CPT code for revision total knee arthroplasty and the CPT code for the use of allograft for bone grafting in the knee.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a distal femoral osteotomy to facilitate implant removal and preparation, followed by the insertion of a cemented, modular, highly constrained posterior-stabilized revision implant. The osteotomy site is then stabilized with a plate and screws. The question asks for the most appropriate CPT code for the osteotomy performed in conjunction with the revision arthroplasty. When coding for procedures involving bone cuts or osteotomies performed in conjunction with arthroplasty, it is crucial to determine if the osteotomy is an integral part of the arthroplasty or a separately reportable service. CPT guidelines and National Correct Coding Initiative (NCCI) edits often bundle osteotomies performed solely to facilitate the primary arthroplasty. However, when an osteotomy is performed for a distinct purpose, such as to address significant bone deformity or to facilitate the removal of a severely impacted or fused implant, it may be separately reportable. In this case, the distal femoral osteotomy was performed to address significant bone loss and to facilitate the removal of the old implant, which is a common indication for an osteotomy during a revision arthroplasty with substantial bone deficiency. The subsequent stabilization of the osteotomy site with a plate and screws is also a distinct procedure. The CPT code for a distal femoral osteotomy performed in conjunction with a total knee arthroplasty revision is typically found within the arthroplasty section or as a separate procedure code that may be reported with a modifier if appropriate. The specific code for a distal femoral osteotomy is 27447 (Osteotomy, femur, distal, with or without lengthening, with or without internal fixation). However, when performed in conjunction with a revision arthroplasty, it is often bundled. The key here is the *purpose* of the osteotomy and the *additional work* involved. For revision total knee arthroplasty, the primary CPT code would be 27487 (Revision of total knee arthroplasty, with or without allograft, with or without autograft, with or without internal fixation). The NCCI edits and CPT guidelines generally indicate that osteotomies performed to facilitate the removal of a cemented or impacted prosthesis are considered integral to the revision arthroplasty and are not separately billable. However, if the osteotomy is performed for a *separate indication* or requires significant additional work beyond what is normally associated with removing a standard implant, it might be reportable. In this specific scenario, the osteotomy is performed due to “significant bone loss” and to “facilitate implant removal.” While bone loss can be a factor in revision, the phrasing “facilitate implant removal” often implies it’s part of the primary procedure. However, the additional step of stabilizing the osteotomy site with a plate and screws (which would typically be coded with 27447 if performed alone) suggests a more complex scenario. Let’s consider the options in light of CPT guidelines for arthroplasty revisions. The most appropriate approach is to identify if the osteotomy is considered an integral part of the revision or a distinct, separately reportable procedure. Given the complexity and the need for stabilization, the osteotomy is being performed as a significant component of the revision. CPT code 27447 is for osteotomy, femur, distal, with or without lengthening, with or without internal fixation. When performed in conjunction with a revision arthroplasty, it is often bundled. However, the scenario implies a complex revision where the osteotomy is a necessary step due to bone loss and difficulty in implant removal, and the osteotomy site is then internally fixed. The correct approach is to determine if the osteotomy is considered a component of the revision arthroplasty or a separately billable procedure. CPT guidelines often bundle osteotomies performed to facilitate implant removal. However, the additional stabilization with a plate and screws suggests a more involved procedure. Considering the specific context of revision arthroplasty and the performance of an osteotomy with internal fixation, the correct coding often involves reporting the primary revision arthroplasty code (27487) and potentially an osteotomy code with a modifier if the osteotomy is deemed to be performed for a separate indication or involves significant additional work beyond the scope of the primary procedure. However, CPT code 27447 specifically describes the osteotomy itself. When an osteotomy is performed as part of a more complex procedure like a revision arthroplasty, and the osteotomy site requires separate fixation, it can sometimes be reported. The key is the intent and the complexity. Let’s re-evaluate the scenario. The osteotomy is performed to address bone loss and facilitate removal. The osteotomy site is then stabilized with a plate and screws. This suggests that the osteotomy is a distinct surgical step that requires separate management. The CPT code for a distal femoral osteotomy with internal fixation is 27447. While revision arthroplasty codes exist, the question focuses on the osteotomy. In complex revisions where an osteotomy is performed and stabilized, it can be reported separately. The correct CPT code for a distal femoral osteotomy with internal fixation is 27447. This code accurately reflects the surgical action described. While revision arthroplasty is also performed, the question specifically asks for the code for the osteotomy. In cases of significant bone loss requiring osteotomy and subsequent fixation, this osteotomy code is often reportable in addition to the revision arthroplasty, provided appropriate modifiers are used to indicate the distinct procedural service. The calculation is not a numerical one, but rather a selection of the most appropriate CPT code based on the described surgical procedure. The procedure involves a distal femoral osteotomy with internal fixation. The CPT code that specifically describes this action is 27447. This code is chosen because it directly represents the surgical manipulation of cutting the distal femur and stabilizing it with hardware. The explanation focuses on why this code is appropriate in the context of a complex revision arthroplasty, highlighting the distinct nature of the osteotomy and its fixation. The rationale emphasizes that while revision arthroplasty is performed, the osteotomy itself is a significant, separately managed component that warrants its own code. Final Answer: 27447

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a posterior cruciate ligament (PCL) sacrifice and uses a femoral stem with a tibial component that incorporates a highly cross-linked polyethylene insert, along with a metaphyseal sleeve for enhanced stability. The question asks to identify the most appropriate ICD-10-CM code for the underlying condition necessitating this extensive surgical intervention. The patient presents with a failed primary total knee arthroplasty, leading to instability and bone loss. The ICD-10-CM coding system requires specificity regarding the reason for the revision. The documentation indicates a mechanical complication of the prosthetic joint, specifically loosening and instability, which are common sequelae of arthroplasty failure. The use of a constrained prosthesis and bone grafting (implied by bone loss and metaphyseal sleeve) further supports a diagnosis of mechanical complication. Let’s analyze the potential coding categories: – **T84.5- (Infection and inflammatory reaction due to internal joint prosthesis):** This category is for infections, which are not the primary issue described. – **T84.6- (Mechanical complication of internal joint prosthesis):** This category encompasses loosening, instability, and breakage of the prosthesis. The description of instability and the need for a constrained implant strongly points to this category. – **M17.0 (Bilateral primary osteoarthritis, unspecified knee):** This code is for primary osteoarthritis and does not capture the complication of a failed prosthesis. – **Z47.1 (Encounter for fitting and adjustment of prosthetic joint):** This code is for encounters related to the prosthetic device itself, not the underlying pathology or complication leading to revision surgery. Within the T84.6- category, the specific subcategory for mechanical complication of internal knee prosthesis is T84.62-. The documentation highlights instability and loosening as the primary drivers for the revision. Therefore, a code reflecting mechanical complication of the internal knee prosthesis is most appropriate. The specific code for mechanical complication of internal knee prosthesis, unspecified, is T84.620A. The ‘A’ signifies an initial encounter for the complication. The detailed description of the surgical procedure, including PCL sacrifice and the use of a constrained implant, underscores the severity of the mechanical complication.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a distal femoral osteotomy to facilitate component removal and implant preparation. Following the osteotomy, a bone graft is utilized to address the metaphyseal defect. The question asks for the appropriate ICD-10-CM code for the underlying condition necessitating this extensive surgical intervention. The patient’s history of a failed primary total knee arthroplasty, evidenced by loosening and instability, points towards a mechanical complication of the previous implant. The revision surgery, including the osteotomy and bone grafting, indicates a severe degree of bone loss and implant failure. Within ICD-10-CM, codes related to mechanical complications of internal orthopedic prosthetic devices, implants, and grafts are found in Chapter 19 (Injury, poisoning and certain other external causes of morbidity), specifically within the T84 category (Complications of internal orthopedic prosthetic devices, implants and grafts). Code T84.04XA, Mechanical complication of internal right knee prosthesis, initial encounter, is the most appropriate code. The “mechanical complication” aspect directly addresses the loosening and instability of the prior prosthesis. The “internal right knee prosthesis” specifies the location. The “initial encounter” (XA) is used because this is the first encounter for the management of this specific mechanical complication, even though it’s a revision surgery. While other codes might describe the revision surgery itself (CPT codes), the ICD-10-CM code must reflect the *reason* for the surgery. Codes related to osteoarthritis (M17.-) would be a precursor to the initial arthroplasty, not the reason for the revision due to mechanical failure. Codes for pathological fractures (e.g., M84.5-) are not indicated as the primary issue is implant failure, not a pathological bone process. Therefore, T84.04XA accurately captures the principal diagnosis driving the complex revision procedure.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss requiring augmentation. The initial procedure involved a posterior-stabilized (PS) prosthesis. The revision procedure addresses polyethylene wear and aseptic loosening, necessitating the use of a constrained liner and augments to restore joint stability and bone stock. The CPT code for a revision total knee arthroplasty is 27487. This code encompasses the complexity of revising a previously performed total knee arthroplasty. The addition of augments, which are used to reconstruct bone defects, requires specific modifiers to accurately reflect the service. When augments are used in conjunction with a revision arthroplasty, the appropriate HCPCS Level II codes from the range J0000-J9999 are utilized to report the materials. For bone augmentation in joint replacement, the specific HCPCS code for bone graft or substitute material is typically reported. In this case, the use of femoral and tibial augments, along with a constrained liner, indicates a complex revision. The explanation of the correct coding involves understanding that the primary procedure is the revision TKA. The augments are considered supply items or materials used to facilitate the reconstruction of bone defects. Therefore, the CPT code for the revision procedure (27487) is the base code. The augments themselves are reported using appropriate HCPCS Level II codes, which are not explicitly provided in the options but are implied by the scenario’s description of bone loss and augmentation. The question focuses on the *type* of coding required for these components in the context of a revision. The use of a constrained liner is inherent to the complexity of the revision and is not separately coded with a modifier; it’s part of the procedure itself. Therefore, the correct approach is to identify the primary CPT code for the revision and recognize that the augments are reported with separate HCPCS Level II codes, not as modifiers to the CPT code. The options provided test the understanding of how to represent these complex reconstructive elements within the coding framework. The correct option reflects the principle that specific materials used for reconstruction, like augments, are typically reported with their own codes, rather than being bundled into the procedural code or represented by a general modifier.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The primary diagnosis is a failed total knee arthroplasty with aseptic loosening and instability. The surgical procedure involves removal of the old components, debridement of the joint, and implantation of a revision prosthesis with augments to address the bone loss. The complexity of the revision, the use of augments, and the need for a constrained implant all contribute to the higher level of coding required. When coding for revision arthroplasty, it is crucial to identify the primary reason for the revision and the specific techniques and implants used. In this case, the aseptic loosening of the prior components is the principal diagnosis driving the surgical intervention. The use of augments to reconstruct the bone defects and the selection of a constrained implant to manage the instability are key procedural elements that necessitate specific CPT codes. The documentation supports the complexity of the revision, indicating extensive bone loss and the need for specialized components. Therefore, the coding should reflect the revision nature of the procedure, the specific joint involved, and the advanced techniques employed to restore stability and function. The selection of a code that encompasses the revision, the use of augments, and the constrained nature of the implant is paramount for accurate reimbursement and data collection, aligning with the rigorous standards expected at Certified Orthopaedic Surgery Coder (COSC) University.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the use of a constrained prosthesis. The primary procedure is a revision of a previously failed TKA. The documentation indicates the use of a constrained implant due to ligamentous instability, which is a specific type of implant used when collateral ligaments are insufficient to maintain joint stability. This necessitates the use of a specific CPT code that reflects the complexity and type of implant. When coding for revision arthroplasty, the surgeon’s documentation is paramount. The use of a “constrained prosthesis” implies a higher level of complexity and often a different CPT code than a standard revision. The scenario also mentions “significant bone loss” and the need for “bone grafting,” which are important factors in selecting the correct code. Let’s analyze the CPT coding for revision arthroplasty. The CPT manual provides specific codes for revision of total knee arthroplasty. These codes are differentiated by whether it is a primary or revision procedure, and the complexity of the revision. For revision TKA, codes typically exist for the femoral component, tibial component, and patellar component. However, the use of a constrained prosthesis often falls under a more specific or bundled code that accounts for the increased complexity and specialized implant. Considering the options provided, we need to identify the code that best represents a revision TKA with a constrained prosthesis and bone grafting. Code 27487 (Revision of total knee arthroplasty, with or without allograft; with proximal tibial bone allograft, or with distal femoral bone allograft, or with both) is a strong candidate because it addresses revision TKA with bone allograft. However, it doesn’t explicitly mention the “constrained prosthesis” aspect. Code 27486 (Revision of total knee arthroplasty, with or without allograft; without bone allograft) is for revisions without bone grafting, which is not the case here. Code 27488 (Revision of total knee arthroplasty, with or without allograft; with proximal tibial bone allograft, or with distal femoral bone allograft, or with both) is identical to 27487, suggesting a potential typo in the options or a need to carefully distinguish nuances. However, assuming they are distinct for the purpose of this question, we must look for the most encompassing code. Code 27487 is generally used for revision TKA with bone grafting. The use of a constrained prosthesis is a critical detail that often dictates the specific code or requires additional modifiers. In many coding systems, the use of a constrained implant for instability is bundled into the primary revision code if it’s the standard approach for that level of instability. However, if the constrained implant itself is a separate billable item or if the code specifically addresses this, it would be preferred. Given the scenario of a revision TKA with a constrained prosthesis and bone grafting, the most appropriate CPT code would be one that reflects the complexity of revision surgery, the use of grafting, and implicitly or explicitly accounts for the specialized implant. CPT code 27487 is the most fitting among the options provided as it specifically addresses revision TKA with bone allograft, which is a key component of the described procedure. While the term “constrained prosthesis” isn’t explicitly in the code description, it is often implied or accounted for within the complexity of revision codes that include bone grafting to address significant instability and bone loss. The use of a constrained implant is a surgical decision made due to instability, which is often a consequence of bone loss and ligamentous compromise, making the bone grafting and revision code the most accurate representation.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The primary diagnosis is a failed primary total knee arthroplasty with aseptic loosening and a secondary diagnosis of bone deficiency. The procedure involves extensive debridement, removal of old hardware, and implantation of a revision knee system with a diaphyseal-engaging stem and a posterior-stabilized insert. The complexity of the revision, the use of a constrained implant due to ligamentous instability, and the significant bone loss necessitate specific coding considerations. When coding for revision arthroplasty, the focus is on the components being revised and the complexity introduced by bone loss and instability. The ICD-10-CM diagnosis codes should reflect the reason for the revision (aseptic loosening, failed implant) and the specific condition (bone deficiency). The CPT codes will describe the surgical work performed. For a revision total knee arthroplasty with bone loss and the use of a constrained prosthesis, the appropriate CPT code would be one that accounts for the complexity of revision, the use of augmentation (like bone graft or cementless stems for diaphyseal fixation), and the specific type of implant used to address instability. Given the description of a revision with significant bone loss and the need for a posterior-stabilized, constrained implant, the coding must reflect the advanced nature of the procedure. The use of diaphyseal-engaging stems for fixation in cases of significant bone loss is a key factor in selecting the most accurate CPT code, as it indicates a more involved reconstruction than a standard revision. The posterior-stabilized insert is standard for many revision knees addressing instability. Therefore, the code that best captures the revision of a total knee arthroplasty with the use of diaphyseal fixation and a posterior-stabilized component, addressing significant bone loss, is the most appropriate. The correct approach involves identifying the primary procedure as a revision total knee arthroplasty. The specific details of the revision, such as the use of diaphyseal-engaging stems to address bone deficiency and the posterior-stabilized insert to manage instability, are crucial for selecting the most accurate CPT code. The ICD-10-CM codes should reflect the aseptic loosening of the previous prosthesis and the bone deficiency. The explanation focuses on the surgical technique and the anatomical challenges addressed, which directly inform the selection of the CPT code that encompasses the complexity of the revision, the fixation method, and the type of implant used to restore stability.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained implant. The primary procedure is a revision of a prior TKA. The bone loss necessitates the use of augments, specifically femoral and tibial augments, to restore bone stock and provide a stable foundation for the revision implant. The use of a constrained implant is indicated due to ligamentous instability, which is a common complication in revision TKA. The operative report details the removal of the old prosthesis, debridement of scar tissue and cement, preparation of the bone surfaces, insertion of the augments, implantation of the revision components, and closure. When coding this scenario for Certified Orthopaedic Surgery Coder (COSC) University, the focus is on accurately reflecting the complexity and components of the surgery. The base code for a revision TKA is identified. Then, the addition of augments requires specific add-on codes. Femoral augments are coded using CPT code 27487 (Revision of total knee arthroplasty, with proximal tibial and/or distal femoral prosthetic revision, including appropriate instrumentation, removal of prior component, and closure, with or without augmentation of bone, with or without insertion of new component, with or without manipulation of the knee, and without external fixation, revision of total knee arthroplasty, with proximal tibial and/or distal femoral prosthetic revision, including appropriate instrumentation, removal of prior component, and closure, with or without augmentation of bone, with or without insertion of new component, with or without manipulation of the knee, and without external fixation). However, the specific use of augments, especially when requiring separate coding for distal femoral and proximal tibial augmentation, necessitates the use of specific add-on codes. CPT code 27488 (Revision of total knee arthroplasty, with proximal tibial prosthetic revision, including appropriate instrumentation, removal of prior component, and closure, with or without augmentation of bone, with or without insertion of new component, with or without manipulation of the knee, and without external fixation) is for tibial revision. For distal femoral augmentation, CPT code 27486 (Revision of total knee arthroplasty, with distal femoral prosthetic revision, including appropriate instrumentation, removal of prior component, and closure, with or without augmentation of bone, with or without insertion of new component, with or without manipulation of the knee, and without external fixation) is used. Since both distal femoral and proximal tibial augments were used, both add-on codes are applicable. The use of a constrained implant is inherent in the revision procedure when instability is present and is typically captured within the primary revision code or specific descriptors of the implant used, rather than a separate CPT code unless a specific revision component is separately billable and coded. Therefore, the most accurate coding reflects the revision TKA with both distal femoral and proximal tibial augmentation. The correct combination of codes would be the primary revision code along with the specific augmentation codes. For the purpose of this question, we are focusing on the augmentation codes. The base code for revision TKA is 27487. The distal femoral augmentation is coded with 27486. The proximal tibial augmentation is coded with 27488. The question asks for the codes for the *augmentation* specifically. Therefore, the correct codes for the augmentation are 27486 and 27488.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon also performs a debridement of infected tissue and cultures are taken. The primary procedure is the revision of the total knee arthroplasty. The debridement of infected tissue is an integral part of managing the infection and preparing the site for the revision, and is typically included in the primary procedure code unless it is a separate, distinct procedure with its own encounter. However, the documentation specifies “extensive debridement of infected tissue and bone,” which, when performed in conjunction with a major reconstructive procedure like a revision arthroplasty, often warrants separate reporting if it meets the criteria for distinct procedural services. The collection of cultures during the debridement is a standard part of the workup for infection and is not separately billable. When coding for revision arthroplasties, the complexity is often dictated by the degree of bone loss and the type of implant used. A constrained prosthesis indicates a higher level of instability, requiring more complex surgical technique and implant selection. ICD-10-CM coding would focus on the reason for the revision, such as loosening of the prosthesis or infection. CPT coding would involve selecting the appropriate code for revision total knee arthroplasty, considering the approach and any specific components used. The use of a constrained implant and the extensive debridement are key factors in determining the appropriate CPT code and any necessary modifiers. Given the extensive debridement and the use of a constrained implant, the most appropriate coding approach would reflect the complexity of the revision and the management of the infection. The selection of a specific CPT code for revision total knee arthroplasty with a constrained implant, coupled with a code for the debridement of infected tissue, accurately captures the services rendered. The ICD-10-CM code would reflect the infected prosthetic joint and the reason for the revision. The correct CPT code for this scenario would be one that encompasses revision total knee arthroplasty with a constrained implant, and a separate code for the debridement of infected tissue. The ICD-10-CM coding would reflect the infected prosthetic joint and the reason for revision.

The scenario describes a patient undergoing a total knee arthroplasty (TKA) with a posterior stabilized (PS) implant. The surgeon performs a medial parapatellar arthrotomy for exposure, then proceeds with femoral and tibial component preparation. Post-operatively, the patient experiences significant pain and swelling, necessitating a diagnostic arthroscopy. During this subsequent procedure, it is discovered that the tibial insert has dislodged from the tibial baseplate. To accurately code this situation for Certified Orthopaedic Surgery Coder (COSC) University’s rigorous curriculum, one must consider the initial procedure and the subsequent complication. The initial TKA would be coded using appropriate CPT codes for the arthroplasty itself, likely involving codes for total knee replacement, hemiarthroplasty, or revision, depending on the specifics not detailed here but assumed to be a primary total knee. However, the critical element for this question is the complication and its management. The dislodged tibial insert represents a mechanical complication of the prosthetic implant. When a prosthetic device fails due to mechanical issues, and the repair involves removing and replacing the failed component or reattaching it, the coding reflects the revision or repair of the implant. In this case, the diagnostic arthroscopy is performed to identify the problem, but the core issue is the failed tibial insert. The subsequent management would likely involve removing the dislodged insert and potentially replacing it or re-securing it to the baseplate. This falls under the category of revision arthroplasty or repair of a prosthetic implant. The correct coding approach for a dislodged tibial insert requiring intervention would involve codes that specifically address the revision of the prosthetic joint due to mechanical failure. Codes for revision of total knee arthroplasty are designed to capture these scenarios. Specifically, CPT codes such as 27487 (Revision of total knee arthroplasty, with or without allograft, posterior stabilized prosthesis, including: tibial component, femoral component, patellar component, removal of components, bone grafting, and all instrumentation, etc.) or similar codes for revision of the tibial component would be appropriate, depending on whether the femoral or patellar components were also revised or removed. The key is that the intervention is a revision due to mechanical failure of the implant. The diagnostic arthroscopy itself, while performed, is integral to the management of the complication and would not be separately coded if the primary purpose was to address the implant failure. Instead, the revision procedure code encompasses the work done to correct the mechanical issue. Therefore, the most accurate coding reflects the revision of the total knee arthroplasty due to the dislodged tibial insert.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained implant. The primary procedure is a revision of a previously implanted TKA. The bone loss necessitates the use of augments, specifically femoral and tibial augments, to restore bone stock and provide a stable foundation for the revision components. The use of a constrained implant is indicated due to ligamentous instability, which is a common complication of revision TKA, especially with extensive bone loss. When coding for such a procedure, the coder must identify the primary procedure, which is the revision TKA. Then, they must identify all additional services performed. The addition of femoral and tibial augments are separately billable services and require specific CPT codes. The use of a constrained liner or implant is also a distinct component that needs to be coded. Let’s break down the coding: 1. **Revision Total Knee Arthroplasty:** The base code for a revision TKA would be selected based on whether it’s a primary or secondary procedure, and the specific components involved (femoral, tibial, patellar). For a revision, we’d look at codes like 27487 (Revision of total knee arthroplasty, with or without allograft, femoral and tibial components; with or without patellar component). 2. **Femoral Augment:** For the femoral augment, the appropriate CPT code would be 27488 (Bone graft, femoral, for revision of total knee arthroplasty, when performed). 3. **Tibial Augment:** Similarly, for the tibial augment, the CPT code would be 27489 (Bone graft, tibial, for revision of total knee arthroplasty, when performed). 4. **Constrained Component:** The use of a constrained implant, which provides additional mediolateral stability, is often bundled into the primary revision code if it’s a standard feature of the implant system. However, if it represents a significant modification or a specific type of implant not inherently covered, it might require additional coding or a modifier. In many coding guidelines, the use of a constrained component is considered part of the revision TKA itself, especially when indicated for instability. However, some payers may require additional reporting or specific modifiers. For the purpose of this question, we assume the constrained implant is a specific type of revision component that requires separate identification if not inherently included in the base revision code. If a specific code for a constrained component is not available, modifiers might be used to indicate the complexity. However, given the options, we are looking for the most comprehensive and accurate representation of the services. Considering the scenario of a revision TKA with both femoral and tibial augments and a constrained implant, the most accurate coding would involve the primary revision code along with codes for the augments. The constrained nature of the implant is a critical detail that influences the complexity and potentially the selection of the primary revision code or the need for additional modifiers. However, without specific codes for “constrained implant” as a separate billable item in this context, the focus remains on the revision and the bone grafting materials. The question asks for the most appropriate coding *approach* to represent the complexity. The core services are the revision TKA, the femoral augmentation, and the tibial augmentation. The constrained nature of the implant is a descriptor of the *type* of revision performed. Therefore, the coding should reflect the revision itself, the augmentation of both bone sites, and the fact that it’s a revision. Let’s re-evaluate the options based on standard coding practices for revision TKA with bone loss and instability. The CPT codes for bone grafts (27488, 27489) are used when bone graft material is utilized to address bone loss. The term “augment” in this context implies the use of such materials. The “constrained implant” implies a specific type of revision component designed for instability. The correct coding sequence would involve the primary revision code, followed by codes for the bone grafts (augments) and potentially a modifier to indicate the constrained nature if not inherent in the primary code. However, the options provided are combinations of CPT codes. Let’s assume the base revision TKA is coded as 27487. Femoral augment: 27488 Tibial augment: 27489 The question is about the *coding approach* for the entire scenario. The most comprehensive representation of the services performed, including the bone loss management and the revision itself, would involve coding for the revision, the femoral augmentation, and the tibial augmentation. The constrained nature is a characteristic of the revision. Therefore, the combination of codes representing the revision TKA, the femoral bone graft, and the tibial bone graft is the most accurate representation of the services rendered. Final Answer Calculation: The scenario involves a revision TKA, femoral augmentation, and tibial augmentation. – Revision TKA: CPT 27487 (Revision of total knee arthroplasty, with or without allograft, femoral and tibial components; with or without patellar component) – Femoral Augment: CPT 27488 (Bone graft, femoral, for revision of total knee arthroplasty, when performed) – Tibial Augment: CPT 27489 (Bone graft, tibial, for revision of total knee arthroplasty, when performed) The correct coding approach would encompass these distinct services. The most accurate representation of the services performed, reflecting the complexity of a revision total knee arthroplasty with both femoral and tibial bone loss addressed by augments, and the use of a constrained implant, would involve coding for the revision procedure itself, along with the specific bone grafting procedures performed on both the femur and the tibia. The constrained nature of the implant is a critical factor in the surgical decision-making and the selection of implant type, and it is implicitly addressed by the complexity of the revision and the need for augmentation. Therefore, the combination of codes for the revision TKA, the femoral bone graft, and the tibial bone graft accurately captures the performed services. The correct coding approach involves identifying the primary procedure (revision TKA), and then separately coding for the additional services provided, such as the bone grafting to address significant bone loss on both the femoral and tibial sides. The use of a constrained implant is a key detail that dictates the type of revision performed and is often associated with ligamentous instability, which is a common reason for needing such implants. While there isn’t a separate CPT code specifically for “constrained implant” in isolation for a TKA revision in the same way there are for bone grafts, its use is integral to the revision procedure itself and is often implied by the selection of specific implant systems designed for such instability. Therefore, the most appropriate coding would reflect the revision, the femoral augmentation, and the tibial augmentation. The correct answer is the option that includes the CPT codes for revision total knee arthroplasty, femoral bone graft, and tibial bone graft. The correct answer is: CPT 27487, CPT 27488, CPT 27489

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The primary diagnosis is a failed primary total knee arthroplasty with aseptic loosening and instability. The surgical procedure involves removal of the old prosthesis, debridement of infected or necrotic tissue, bone grafting to address the bone loss, and implantation of a revision prosthesis. The complexity of the revision, the use of bone allograft, and the implantation of a highly constrained implant all contribute to the increased complexity and resource utilization. When coding for such a scenario, the coder must accurately reflect the services provided. The ICD-10-CM diagnosis code should capture the aseptic loosening of the prosthetic joint and the instability. For the CPT code, the focus is on the surgical procedure. Revision arthroplasty codes are distinct from primary arthroplasty codes and often have specific codes for different joints and levels of complexity. The use of a constrained prosthesis and the management of significant bone loss (often addressed with bone grafting, which may have its own CPT code or be bundled depending on the primary procedure code) are critical factors. The documentation must support the medical necessity for the revision and the specific techniques employed. Considering the options, a code reflecting a revision total knee arthroplasty with management of significant bone loss and the use of a constrained implant is necessary. The specific CPT code for revision total knee arthroplasty is typically found within the range of 27486-27488, with modifiers used to indicate laterality and potentially other factors. The complexity of this revision, including the bone loss and constrained implant, would necessitate a code that accounts for these factors, often the highest level of service within the revision knee arthroplasty codes. The explanation focuses on the principles of selecting the appropriate CPT code for a complex revision procedure, emphasizing the need to capture the extent of the surgery and the specific components used, aligning with the advanced coding principles taught at Certified Orthopaedic Surgery Coder (COSC) University. The correct coding reflects the significant resources and expertise required for such a procedure, ensuring accurate reimbursement and data collection for quality assessment.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for custom implant components. The primary diagnosis is a failed total knee arthroplasty with loosening and osteolysis. The surgical procedure involves removal of the old components, debridement of infected tissue, and implantation of a revision knee prosthesis with augments to address the bone voids. To determine the appropriate ICD-10-CM diagnosis code, we need to identify the most specific code that reflects the patient’s condition. The patient has a history of total knee arthroplasty (TKA) that has failed due to loosening and osteolysis. 1. **Failed Arthroplasty:** The underlying reason for the revision surgery is the failure of the previous TKA. ICD-10-CM codes for complications of internal prosthetic devices, implants, and grafts are found in Chapter 19 (Injury, poisoning and certain other external causes of morbidity), specifically in the T80-T88 block. 2. **Loosening of Prosthetic Joint:** The loosening of the prosthetic components is a direct complication. Code T84.52XA (Infection and inflammatory reaction due to internal joint prosthesis, not elsewhere classified, knee, initial encounter) is for infection. Code T84.51XA is for infection of internal knee prosthesis. Code T84.53XA is for loosening of internal knee prosthesis. Code T84.54XA is for mechanical complication of internal knee prosthesis. Code T84.55XA is for malposition of internal knee prosthesis. Code T84.56XA is for foreign body accidentally left in body following insertion of internal prosthetic device, implant, or graft. Code T84.57XA is for other complication of internal knee prosthesis. 3. **Osteolysis:** Osteolysis, the breakdown of bone around the implant, is a significant factor contributing to the loosening and bone loss. While there isn’t a single ICD-10-CM code specifically for “osteolysis secondary to prosthetic loosening,” the concept of mechanical complication or loosening is captured. 4. **Revision Procedure:** The surgery is a revision, implying a previous procedure. The diagnosis codes should reflect the current state requiring revision. Considering the options: * T84.53XA (Loosening of internal knee prosthesis, initial encounter) directly addresses the loosening of the prosthetic joint. * T84.54XA (Mechanical complication of internal knee prosthesis, initial encounter) could also be considered, as loosening and osteolysis are mechanical complications. However, “loosening” is more specific. * T84.52XA (Infection and inflammatory reaction due to internal joint prosthesis, not elsewhere classified, knee, initial encounter) is incorrect as the primary issue described is loosening and osteolysis, not infection. * M17.11 (Unilateral primary osteoarthritis, unspecified knee) is incorrect as this is a revision surgery for a failed prosthesis, not primary osteoarthritis. The most accurate and specific ICD-10-CM code for the scenario, reflecting the loosening of the internal knee prosthesis as the primary reason for the revision surgery, is T84.53XA. The “initial encounter” (XA) is appropriate because this is the first encounter for the current episode of care for this specific complication. The explanation of osteolysis and bone loss supports the severity and complexity of the loosening, making T84.53XA the most fitting primary diagnosis.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a distal femoral osteotomy to facilitate implant removal and preparation, followed by the insertion of a cemented, highly constrained posterior-stabilized revision implant with augments to address the bone defects. The documentation also notes the use of a bone graft substitute. To determine the correct CPT code, we must break down the procedure into its component parts and identify the most appropriate codes based on the provided details and the Certified Orthopaedic Surgery Coder (COSC) University’s emphasis on precise coding for complex reconstructive procedures. 1. **Revision Total Knee Arthroplasty (TKA):** The primary procedure is a revision TKA. Given the complexity (bone loss, constrained implant), we look for codes that reflect this. CPT code 27487 (Revision of total knee arthroplasty, with or without allograft; with proximal tibial and distal femoral prosthetic revision) is a strong candidate, but the use of augments and the osteotomy need further consideration. 2. **Distal Femoral Osteotomy:** The surgeon performed a distal femoral osteotomy. CPT code 27445 (Osteotomy, femur, distal shaft or metaphysis; with internal or external fixation) is relevant. However, this code is typically used for fracture management or deformity correction. In the context of revision arthroplasty, osteotomies performed *solely* to facilitate implant removal or preparation are often considered integral to the revision procedure and not separately billable unless they are extensive and performed for a separate indication. The explanation states it was “to facilitate implant removal and preparation,” suggesting it’s integral. 3. **Augments:** The use of augments to address bone defects is a critical component of complex revisions. CPT code 27488 (Revision of total knee arthroplasty, with or without allograft; with proximal tibial prosthetic revision, with augments) and 27489 (Revision of total knee arthroplasty, with or without allograft; with distal femoral prosthetic revision, with augments) are specific to revisions with augments. Since both proximal tibial and distal femoral components were revised, and augments were used, we need to select the most comprehensive code. The scenario specifies “distal femoral osteotomy” and “highly constrained posterior-stabilized revision implant with augments,” implying augments were used on the femur. If augments were also used on the tibia, a combination of codes or a more comprehensive code would be needed. However, the question focuses on the distal femoral aspect and the overall revision. CPT code 27487 is for revision with *prosthetic revision* of both proximal tibia and distal femur. When augments are used, specific codes are often preferred. CPT code 27489 specifically addresses distal femoral prosthetic revision *with augments*. 4. **Bone Graft Substitute:** The use of a bone graft substitute is also documented. CPT codes for bone grafting are typically reported separately when performed in conjunction with arthroplasty. For allograft or autograft, specific codes exist. For bone graft *substitute*, it’s often bundled or coded with a specific HCPCS code if applicable and separately billable. However, the primary focus for the orthopaedic surgeon’s procedure code is the arthroplasty itself. Considering the complexity and the specific components: – The revision TKA with a constrained implant and augments is the core service. – The distal femoral osteotomy, as described, is likely integral to the revision. – The use of augments is key. CPT code 27489 specifically covers distal femoral prosthetic revision with augments. If the tibial component was also revised with augments, a different code or modifier might apply, but based on the emphasis on the distal femur and the general description of revision, 27489 is a strong candidate for the femoral component’s complexity. However, the most comprehensive code for a revision TKA involving both tibial and femoral components with augments is CPT code 27488 (Revision of total knee arthroplasty, with or without allograft; with proximal tibial and distal femoral prosthetic revision, with augments). This code encompasses the revision of both major components and explicitly includes the use of augments, which is a critical factor in complex revisions like the one described. The distal femoral osteotomy, if performed solely for access, is generally considered part of the revision. The bone graft substitute’s coding would depend on specific payer guidelines and whether it’s considered a supply or a separately billable procedure. For the surgical procedure itself, 27488 best captures the complexity of a revision TKA with augments involving both tibial and femoral components. Therefore, the correct coding approach for the described procedure, emphasizing the revision of both tibial and femoral components with augments, is CPT code 27488. The correct approach involves identifying the primary surgical service (revision TKA), recognizing the complexity indicated by the need for a constrained implant and augments, and selecting the CPT code that most accurately reflects these elements. The use of augments for bone defects during revision arthroplasty is a significant factor that elevates the complexity and necessitates specific coding. The code for revision of total knee arthroplasty with prosthetic revision of both the proximal tibia and distal femur, explicitly including the use of augments, is the most appropriate choice. This code signifies the extensive reconstruction required due to significant bone loss and instability, which is characteristic of the scenario presented. The distal femoral osteotomy, when performed for access during a revision, is generally considered an integral part of the overall revision procedure and not separately billable. Similarly, the bone graft substitute, while important for the procedure, is often coded separately with an HCPCS code or considered a supply, depending on payer rules, but does not change the primary CPT code for the surgeon’s work. The selection of a constrained implant further underscores the complexity and the need for a code that accounts for these challenging circumstances.

The scenario involves a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained implant. The primary procedure is a revision TKA. The documentation indicates the use of a constrained implant due to ligamentous instability, which is a specific type of implant used in revision arthroplasty when standard implants are insufficient. The bone loss necessitates bone grafting, which is an additional procedure. The complexity of the revision and the use of a constrained implant are key factors in selecting the appropriate CPT code. For revision TKA, CPT codes 27486 (Revision of total knee arthroplasty, with or without allograft, with or without autograft, for failed wound closure or wound dehiscence, or removal of infected prosthetic material) and 27487 (Revision of total knee arthroplasty, with or without allograft, with or without autograft, for failed arthroplasty, with or without bone graft, with or without prosthetic/bone graft augmentation, with or without constrained prosthesis) are relevant. Given the presence of significant bone loss requiring grafting and the use of a constrained prosthesis, code 27487 is the most appropriate. The documentation does not suggest a wound closure issue or simple removal of infected material, which would point to 27486. The additional bone grafting is bundled into 27487 when used for failed arthroplasty with bone graft augmentation. The use of a constrained prosthesis is explicitly included in the description of 27487. Therefore, the correct CPT code is 27487.

The scenario involves a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained prosthesis. The primary procedure is a revision TKA, which is coded using the Current Procedural Terminology (CPT) system. The complexity arises from the bone loss, necessitating bone grafting. Bone grafting in conjunction with a joint replacement is typically reported with specific CPT codes that reflect the source and type of graft. For a revision TKA, the base code for the revision itself is crucial. The use of a constrained prosthesis indicates a higher level of complexity and potential instability, which is often captured by specific modifiers or by the inherent nature of the revision codes themselves, depending on the payer and specific coding guidelines. In this case, the revision TKA is performed on the right knee. The CPT code for a revision of a total knee arthroplasty, without the use of a distal femoral component, is 27487. The documentation specifies the use of an allograft for bone grafting. The CPT code for allograft for knee arthroplasty is 20931. Therefore, the correct coding would involve reporting both the revision arthroplasty and the allograft. The question asks for the most appropriate coding combination for the described scenario. The combination of 27487 and 20931 accurately reflects the revision procedure and the use of an allograft for bone reconstruction. Other options may include codes for primary TKAs, different types of grafts, or incomplete reporting of the services rendered. For instance, 27447 is for a primary TKA, which is incorrect for a revision. Codes like 20930 (autograft) or 20936 (allograft, bone graft, not otherwise specified) are less specific than 20931 for knee arthroplasty allografts. The use of a constrained prosthesis is an inherent complexity of the revision procedure itself and is typically not coded with a separate CPT code but is reflected in the choice of the revision code and potentially a modifier if required by specific payer guidelines, though no specific modifier is universally mandated for “constrained prosthesis” in this context without further payer-specific guidance. Thus, the combination of the revision TKA code and the allograft code is the most accurate representation of the services provided.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon also performs a debridement of infected tissue and cultures are taken. The primary procedure is the revision of the total knee arthroplasty. The bone loss necessitates the use of bone allografts, which are separately reportable. The debridement of infected tissue is an integral part of the revision surgery when infection is present and is not typically coded separately unless it is a distinct, extensive procedure beyond what is inherent to the revision. However, the creation of a separate surgical field for the allograft preparation and placement, especially when it involves significant bone grafting, can warrant separate reporting. The infectious process itself, while the reason for the debridement, is addressed by the surgical intervention rather than a separate code for the infection itself in this context. The cultures are part of the debridement and infection workup. Therefore, the most appropriate coding would involve the primary revision arthroplasty, the bone allograft, and potentially a code for the extensive debridement if it meets the criteria for separate reporting beyond the primary procedure. Considering the options, the most comprehensive and accurate representation of the services provided, focusing on the distinct procedural components and the use of advanced materials, is crucial. The question tests the understanding of how to code complex revision surgeries with bone grafting and the nuances of debridement coding in the presence of infection. The correct approach involves identifying the primary surgical service, the use of grafts, and any separately reportable ancillary procedures.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss, requiring augmentation with allograft. The primary procedure is the revision of the total knee arthroplasty. The bone loss necessitates the use of allograft, which is a separate procedure performed to reconstruct the bone defect. The documentation indicates the use of a posterior stabilized (PS) femoral component and a posterior tibial component. The complexity of the revision, particularly with bone grafting, warrants the use of specific modifiers to accurately reflect the services rendered and ensure appropriate reimbursement. The core procedure is the revision total knee arthroplasty. According to CPT guidelines, revision of a total knee arthroplasty is reported using codes from the 27486-27488 range, depending on whether it’s a partial or total revision and if a prosthesis was removed. Given the description of replacing both femoral and tibial components, a code reflecting a total knee revision is appropriate. The use of allograft for bone reconstruction is a significant component of the procedure. CPT codes for bone grafting are found in the 20900-20938 range. Specifically, allograft for structural bone graft is reported with code 20931. This code represents the harvesting and preparation of the allograft for implantation. When a procedure is performed with a significant additional service that is separately reportable, modifiers are crucial. The scenario involves a revision arthroplasty and a bone graft. The modifier -59 (Distinct Procedural Service) or the newer -X{ESPU} modifiers (e.g., -XU for unusual non-overlapping service) might be considered if the bone graft were performed at a completely separate anatomical site or on a different date. However, in this case, the bone graft is integral to the revision arthroplasty at the same site. The modifier -22 (Increased Procedural Services) is often appended to the primary arthroplasty code when significant additional work is performed, such as extensive debridement, management of severe adhesions, or in this case, the substantial bone loss requiring allograft reconstruction. The documentation of “significant bone loss requiring augmentation with allograft” strongly supports the use of -22 to indicate the increased complexity and time involved beyond the typical revision procedure. Therefore, the most accurate coding approach involves reporting the revision total knee arthroplasty with the -22 modifier to account for the complexity introduced by the bone loss and allograft use, and separately reporting the allograft procedure. The specific CPT code for the revision arthroplasty would depend on the exact components revised (femoral, tibial, or both) and whether a prosthesis was removed. Assuming a total knee revision where both components are addressed and a prosthesis was removed, a code like 27487 (Revision of total knee arthroplasty, with or without allograft; femoral, tibial, and prosthetic components removed) would be a starting point, to which the -22 modifier would be appended. The allograft procedure would be reported with 20931. The question asks for the most appropriate coding *approach* for the *entire encounter*, considering the complexity. While reporting both codes is necessary, the question implicitly asks how to capture the *increased work* of the revision due to the allograft. The -22 modifier directly addresses this increased work on the primary procedure. The correct coding approach is to report the primary revision arthroplasty procedure with the -22 modifier to reflect the significant bone loss and allograft reconstruction, and to report the allograft procedure (20931) separately. This accurately captures the complexity and extent of services provided, aligning with the principles of accurate and compliant coding taught at Certified Orthopaedic Surgery Coder (COSC) University.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a distal femoral osteotomy to address the bone defect and then implants a cemented, modular, highly constrained posterior-stabilized revision knee prosthesis. The operative report details the use of antibiotic-impregnated cement for both the femoral and tibial components, as well as the patellar component. The question asks for the appropriate CPT code for the *entire* procedure, considering the complexity and components used. To arrive at the correct coding, we must break down the procedure into its billable components and select the most accurate and comprehensive codes. The core procedure is a revision of a total knee arthroplasty. Given the significant bone loss and the use of a constrained prosthesis, we look for codes that reflect this complexity. First, the revision of the total knee arthroplasty, including the femoral, tibial, and patellar components, is coded. For a revision with a highly constrained prosthesis and modular components, the appropriate CPT code is 27487 (Revision of total knee arthroplasty, with or without allograft; with implantation of component(s) with porous coating, highly congruent articulating surfaces, or custom-made components, or with bone allograft or autograft, or with extracortical or cortical bone graft for bridging or augmentation of bone defect, or with diaphyseal sleeve or strut). This code encompasses the complexity of the revision, the use of specialized components, and the management of bone defects. Next, the distal femoral osteotomy performed to address the bone defect needs to be coded. The CPT code for a distal femoral osteotomy is 27445 (Osteotomy, femur, distal, for correction of malalignment of knee). Finally, the use of antibiotic-impregnated cement is a supply and not separately billable with a CPT code; it is considered part of the implant and procedure. Therefore, the correct coding combination involves reporting the revision arthroplasty with the complex components and the distal femoral osteotomy. The combination of 27487 and 27445 accurately reflects the services rendered. The explanation focuses on the rationale for selecting these specific codes based on the operative details, emphasizing the complexity of the revision, the type of prosthesis used, and the additional osteotomy procedure. It highlights that the antibiotic-impregnated cement is an integral part of the implant and not separately billable. The explanation also implicitly addresses the importance of understanding the nuances of revision arthroplasty coding and the need to identify and code all distinct, medically necessary procedures performed during the same operative session, aligning with the rigorous standards expected at Certified Orthopaedic Surgery Coder (COSC) University.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the use of a constrained prosthesis. The surgeon also performs a bone graft to address the bone deficit. To accurately code this encounter, the coder must consider multiple CPT codes and appropriate modifiers. First, the primary procedure is the revision total knee arthroplasty. The use of a constrained prosthesis indicates a higher level of complexity and often requires a specific CPT code or modifier depending on the payer and the exact nature of the constraint. For revision total knee arthroplasty with bone allograft, the base CPT code for the revision would be selected. Next, the bone graft is a distinct procedure. If an allograft is used, it is typically reported with a separate CPT code. The documentation specifies “bone graft,” and given the context of a revision arthroplasty with bone loss, an allograft is a common approach. The CPT code for obtaining and preparing an allograft for implantation is relevant here. Furthermore, the complexity of the revision, particularly with significant bone loss and the use of a constrained implant, necessitates modifiers to accurately reflect the service provided and to potentially justify higher reimbursement. Modifiers such as -22 (Increased Procedural Services) might be considered if the bone loss significantly increased the work involved beyond the typical revision, but the use of a constrained prosthesis often has its own specific coding implications or is bundled into the primary procedure’s RVUs. However, the question focuses on the most appropriate *combination* of codes. The specific CPT codes involved would be: 1. CPT code for revision total knee arthroplasty (e.g., 27482 for revision of total knee arthroplasty, with or without allograft, but the specific code might vary based on exact details not provided, and the use of a constrained prosthesis might imply a different base code or a modifier). For the purpose of this question, we assume a standard revision code is the starting point. 2. CPT code for the bone graft. For an allograft, a code like 20930 (Allograft, morselized, or placement of morselized allograft, for spine surgery only) is not applicable here. A more appropriate code for bone grafting in extremity surgery would be considered. For example, CPT code 20936 (Autograft for structural bone graft, pelvis [e.g., iliac crest, crest of ilium], acetabulum, or posterior weight bearing area, or hemipelvis; for transplantation into the spine or pelvis) is for spine/pelvis. For extremity, codes like 20930-20938 are for spine. For bone grafting in the knee, codes like 20931 (Allograft, morselized, or placement of morselized allograft, for spine surgery only) are not for knee. Let’s consider CPT 20937 (Allograft, morselized, or placement of morselized allograft, for extremity reconstruction) or similar codes for allograft placement in the knee. However, the question implies a specific combination. Let’s re-evaluate based on common orthopedic coding practices for revision knee arthroplasty with bone loss and allograft. A common approach is to report the revision arthroplasty code along with a code for the bone graft. For a constrained prosthesis, the coding might be inherent in the revision code or require a specific modifier if the payer dictates. Considering the options provided, the most comprehensive and accurate coding approach for a revision total knee arthroplasty with significant bone loss requiring a constrained prosthesis and an allograft would involve a code for the revision procedure itself, a code for the allograft, and potentially a modifier to reflect the complexity. Let’s assume the base revision code is 27482 (Revision of total knee arthroplasty, with or without allograft). If the allograft is separately reported, a code like 20937 (Allograft, morselized, or placement of morselized allograft, for extremity reconstruction) might be used. However, many payers bundle allograft placement into the primary arthroplasty code, especially if it’s a standard part of the revision. The use of a “constrained prosthesis” implies a more complex implant, which might be captured by the base CPT code for revision or require a modifier. A more nuanced approach for revision arthroplasty with significant bone loss often involves specific codes for the bone defect and the type of graft. For example, if the bone loss is substantial, codes related to “bone defect” might be used in conjunction with the revision. Let’s consider the possibility that the question is testing the understanding of *when* to report a bone graft separately. If the allograft is used to reconstruct a significant bone defect, it is often reportable. The correct approach is to identify the primary procedure (revision TKA), the secondary procedure (bone graft), and any modifiers that enhance specificity or indicate increased complexity. Without specific CPT codes for “constrained prosthesis” as a standalone item, the complexity is often reflected in the revision code itself or through modifiers. Let’s assume the following CPT codes are relevant for this scenario: – Revision Total Knee Arthroplasty: 27482 – Allograft for extremity reconstruction: 20937 The combination of these two codes represents the core procedures. The question asks for the *most appropriate* coding. Let’s consider the options. The correct option would likely combine the revision procedure with the bone graft, and potentially a modifier if applicable and not bundled. The calculation is conceptual: identify primary procedure, identify secondary procedure, determine if they are separately reportable, and consider modifiers. The correct answer is the option that accurately reflects the revision total knee arthroplasty and the placement of an allograft for bone reconstruction, acknowledging the complexity introduced by the constrained prosthesis and bone loss. The most appropriate coding would involve reporting the revision arthroplasty and the allograft placement, as these are distinct services. The use of a constrained prosthesis is often an inherent part of the revision procedure’s complexity and may not always require a separate code but could influence the RVUs of the primary code or necessitate a modifier like -22 if the bone loss is exceptionally severe and documented. However, the question asks for the coding of the *procedures performed*. The correct combination of codes would be the revision total knee arthroplasty code plus the code for the allograft placement. Final Answer is based on selecting the option that correctly identifies both the revision arthroplasty and the allograft placement. The correct option is the one that includes the CPT code for revision total knee arthroplasty and the CPT code for the placement of an allograft for extremity reconstruction. The correct option is the combination of CPT 27482 and CPT 20937.

The scenario describes a patient undergoing a complex revision total knee arthroplasty with significant bone loss and the need for a constrained prosthesis. The surgeon performs a distal femoral osteotomy to facilitate implant removal and preparation, followed by the insertion of a cemented, highly constrained posterior-stabilized prosthesis with augments to address the bone voids. The question asks for the most appropriate CPT code for the *revision* procedure itself, considering the complexity. To arrive at the correct answer, one must navigate the CPT manual, specifically focusing on the musculoskeletal system section and the subsection for arthroplasty, then revision arthroplasty. The key elements are: revision of a total knee arthroplasty, the use of a constrained prosthesis, and the performance of a distal femoral osteotomy. CPT codes for revision knee arthroplasty are distinguished by whether the prosthesis is cemented or uncemented, and whether it is primary or revision. For revision, codes like 27486 (Revision of total knee arthroplasty, with or without allograft, cemented, for failed arthroplasty, including cutting of bone, removal of prosthesis, and insertion of prosthesis, with or without autograft, and without external fixation) and 27487 (Revision of total knee arthroplasty, with or without allograft, uncemented, for failed arthroplasty, including cutting of bone, removal of prosthesis, and insertion of prosthesis, with or without autograft, and without external fixation) are relevant. The use of augments to address bone loss is typically bundled into these revision codes unless specifically stated otherwise or if a separate procedure code is warranted. A distal femoral osteotomy, when performed in conjunction with a revision arthroplasty, is often reported separately if it meets specific criteria for complexity or is a distinct, significant procedural component. CPT code 27447 (Arthroplasty, knee, condyle and plateau; with or without allograft, cemented or uncemented) is for *primary* knee arthroplasty and is not appropriate for a revision. CPT code 27543 (Femur fracture, distal epiphysis (eg, unicondylar) (proximal tibial or distal femoral); open treatment of fracture or dislocation) is for fracture management and not revision arthroplasty. CPT code 27488 (Removal of prosthesis, femoral or tibial component only, or both, without reinsertion) is only for removal, not revision with reinsertion. The use of a highly constrained prosthesis and augments indicates a complex revision scenario, often requiring significant bone preparation and reconstruction. While the osteotomy is a significant part of the procedure, it is often considered integral to the complex revision arthroplasty when addressing substantial bone loss. However, the question implies a specific coding consideration for the osteotomy in this context. Upon reviewing the CPT guidelines and common coding practices for complex revisions, the performance of a distal femoral osteotomy in conjunction with a revision total knee arthroplasty, especially when dealing with significant bone loss requiring augments and a constrained implant, is often reported with a modifier or a specific add-on code if available, or it may be considered inherent to the complexity of the revision. However, if the osteotomy is a distinct and separately reportable procedure due to its complexity and contribution to the overall surgical success, it would be coded. Considering the options provided, the most accurate coding would reflect the revision arthroplasty with the complexities described. The use of a cemented, highly constrained prosthesis with augments points towards a complex revision. The distal femoral osteotomy is a significant component. In the absence of a specific add-on code for the osteotomy in this exact scenario within the provided options, the most appropriate approach is to select the code that best encompasses the revision procedure with its inherent complexities. Let’s re-evaluate the options based on standard coding principles for revision arthroplasty. The core procedure is the revision of a total knee arthroplasty. The use of a constrained prosthesis and augments are descriptors of the complexity of the revision. The distal femoral osteotomy is a distinct surgical step. If we consider the possibility of reporting the osteotomy separately, we would look for a code that describes a distal femoral osteotomy. CPT code 27445 (Osteotomy, femur, distal, for correction of malalignment of the knee) is a potential code for a distal femoral osteotomy. However, the question is about the *revision arthroplasty*. The most appropriate CPT code for a revision total knee arthroplasty, especially with the use of a cemented, highly constrained prosthesis and augments, would be a code that reflects this complexity. If the distal femoral osteotomy is considered a separately billable procedure in this context, it would be appended to the revision arthroplasty code. Let’s assume the question is testing the understanding of how to code for the *entire* procedure, including the osteotomy as a distinct component of the revision. The primary procedure is the revision total knee arthroplasty. The distal femoral osteotomy is performed to facilitate this revision. The correct approach involves identifying the primary procedure code for the revision total knee arthroplasty and then considering if the osteotomy is separately reportable. Given the options, we need to find the one that best represents the revision with the described complexities. The scenario involves a revision of a total knee arthroplasty. The use of a cemented, highly constrained prosthesis with augments signifies a complex revision. The distal femoral osteotomy is a significant surgical step. Let’s consider the established coding for revision total knee arthroplasty. CPT code 27486 is for revision of total knee arthroplasty, cemented. The use of augments and a constrained prosthesis are often considered part of the complexity of the revision itself and may not always warrant a separate code unless specific guidelines or modifiers apply. However, a distal femoral osteotomy is a distinct surgical procedure. If the distal femoral osteotomy is performed to address significant bone loss or to facilitate the removal of the old prosthesis and insertion of the new one, it is often considered an integral part of a complex revision. However, some coding guidelines allow for separate reporting of osteotomies performed in conjunction with revision arthroplasties if they are extensive or performed for reasons beyond simple preparation. The correct answer reflects the most comprehensive and accurate coding for the described scenario, considering the revision arthroplasty and the performed osteotomy. The scenario describes a revision of a total knee arthroplasty with a distal femoral osteotomy. The most appropriate code for the revision of a cemented total knee arthroplasty is 27486. The distal femoral osteotomy, when performed as a distinct and necessary step for a complex revision, can be reported separately. Therefore, the combination of the revision code and the osteotomy code, along with appropriate modifiers, would be the most accurate. The provided options are: a) 27486, 27445 b) 27487, 27445 c) 27486, 27543 d) 27447, 27445 Option a) combines the correct code for revision of a cemented total knee arthroplasty (27486) with the correct code for a distal femoral osteotomy (27445). This accurately reflects the described surgical procedure. Option b) uses the uncemented revision code, which is incorrect as the prosthesis is cemented. Option c) uses a code for fracture management, which is not applicable. Option d) uses the code for primary knee arthroplasty, which is incorrect for a revision. Therefore, the correct coding is 27486 for the revision total knee arthroplasty and 27445 for the distal femoral osteotomy. Final Answer is 27486, 27445.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss and the need for a constrained implant. The primary procedure is a revision TKA, which is coded using the Current Procedural Terminology (CPT) system. The complexity arises from the revision nature and the use of a constrained prosthesis, indicating a higher level of difficulty and resource utilization. The CPT codes for total knee arthroplasty, revision, are found within the Musculoskeletal System section. Specifically, codes for revision of total knee arthroplasty are differentiated by whether the procedure involves the femoral, tibial, patellar, or all components. The use of a constrained implant, often referred to as a “hinged” or “stabilized” prosthesis, is typically an indicator of significant instability or bone loss, requiring a more specialized implant. In this case, the surgeon is revising a total knee arthroplasty, replacing all components (femoral, tibial, and patellar). The use of a constrained implant is a key detail. Reviewing the CPT manual, the appropriate code for a revision of total knee arthroplasty, with all components replaced, and utilizing a constrained prosthesis, is 27487. This code specifically encompasses the complexity of a revision with a constrained implant. The explanation of why 27487 is the correct code lies in its specificity. CPT code 27487 is defined as “Revision of total knee arthroplasty, with all components attached to bone (e.g., cementless prosthesis), with or without removal of prior components, with bone allograft and/or augmentation, and with constrained prosthesis.” While the scenario doesn’t explicitly mention bone allograft or augmentation, the term “constrained prosthesis” is the critical differentiator that points to this code for revision TKA. The other options represent different procedures or levels of complexity. For instance, 27486 is for revision of total knee arthroplasty with removal of components, but without the specific mention of a constrained prosthesis, making it less precise for this scenario. Codes like 27447 are for primary total knee arthroplasty, not revisions. 27488 is for revision of total knee arthroplasty with removal of components and without constrained prosthesis, or with posterior stabilized prosthesis, which is less restrictive than a constrained implant. Therefore, the presence of a constrained implant in a revision TKA with all components replaced necessitates the use of 27487 to accurately reflect the surgical service provided and ensure appropriate reimbursement and compliance with coding guidelines. This aligns with the Certified Orthopaedic Surgery Coder (COSC) University’s emphasis on precise and compliant coding practices, reflecting the intricate nature of orthopaedic surgical coding.

The scenario involves a patient undergoing a total knee arthroplasty (TKA) with a complex revision due to a periprosthetic joint infection (PJI). The initial TKA was performed for severe osteoarthritis. The revision surgery involved removal of the existing prosthesis, debridement of infected tissue, and insertion of an antibiotic-laden spacer. The question requires identifying the most appropriate ICD-10-CM code for the underlying condition necessitating the initial surgery, considering the subsequent complication. The patient’s primary diagnosis for the initial total knee arthroplasty was severe osteoarthritis of the knee. In ICD-10-CM, osteoarthritis of the knee is classified under M17. The specific subcategory for primary osteoarthritis of the knee, bilateral, is M17.0, and for primary osteoarthritis of the knee, unilateral, it is M17.1-. Since the scenario does not specify laterality for the initial surgery, but implies a need for revision, we consider the general category. However, the presence of a periprosthetic joint infection (T84.5-) is a complication of the arthroplasty, not the primary reason for coding the initial condition. The question asks for the code representing the *underlying condition* that led to the initial procedure. Severe osteoarthritis is the most fitting description. The correct approach is to identify the ICD-10-CM code that accurately reflects the severe degenerative joint disease that prompted the initial total knee arthroplasty. While the revision surgery and infection are critical for procedural coding and potentially for secondary diagnoses, the question specifically targets the etiology of the first intervention. Therefore, a code for osteoarthritis of the knee is paramount. Considering the severity implied by the need for arthroplasty, a code within the M17 category is appropriate.

The scenario describes a patient undergoing a complex revision total knee arthroplasty (TKA) with significant bone loss requiring augmentation. The surgeon performs a distal femoral osteotomy to facilitate access and implant removal, followed by the insertion of a modular augument to the distal femur and a revision TKA with a constrained posterior-stabilized prosthesis. The osteotomy is performed at the metaphyseal-diaphyseal junction. The primary procedure is the revision TKA, with the osteotomy and augmentation being secondary procedures or components of the primary procedure. To determine the correct coding, we must consider the CPT codes for each distinct service. The revision TKA with a constrained posterior-stabilized prosthesis falls under CPT code 27487 (Revision of total knee arthroplasty, with or without allograft; constrained prosthesis, posterior stabilized, total knee arthroplasty). The distal femoral osteotomy, performed to facilitate the revision, is coded separately. CPT code 27447 (Osteotomy, femur, proximal, distal, or shaft; with internal fixation) is appropriate for a distal femoral osteotomy with internal fixation, which is implied by the need for augmentation and subsequent stable fixation of the revision implant. The modular augument itself is not separately billable with a specific CPT code when it is an integral part of the revision procedure and implant system; it is considered inclusive in the revision arthroplasty code. Therefore, the combination of the revision arthroplasty and the osteotomy is required. The correct coding is therefore the sum of the primary procedure and the distinct, separately reportable secondary procedure. The primary procedure is the revision total knee arthroplasty (27487). The distal femoral osteotomy (27447) is a distinct and necessary step to achieve the surgical goal. When multiple procedures are performed during the same session, the primary procedure is typically reported at 100% of its usual fee, and subsequent procedures may be reported with a reduced fee or modifier, depending on payer guidelines and the specific relationship between the procedures. However, for the purpose of identifying the correct codes that represent the services rendered, both codes are essential. The question asks for the appropriate codes to represent the services. The correct combination of codes is 27487 and 27447.