challenges of total knee arthroplasty in posttraumatic osteoarthritis: A cook book approach
Background: Posttraumatic osteoarthritis of the knee presents unique surgical challenges compared to primary osteoarthritis due to complex intraarticular and extraarticular deformities, ligamentous instability, and preexisting hardware. While total knee arthroplasty (TKA) can provide satisfactory outcomes, the heterogeneity of these deformities requires specialized preoperative planning and surgical techniques to address malalignment and stiffness.
Objective: This article aims to provide a systematic framework for performing primary TKA in patients with complex posttraumatic lower extremity deformities, focusing on indications for deformity correction, implant selection, and exposure strategies.
Key Points: Extraarticular coronal deformities exceeding 20 to 25 degrees generally require staged or concurrent corrective osteotomy, as intraarticular balancing alone may be insufficient. Preoperative assessment must include hip-to-ankle standing radiographs and potentially axial imaging to evaluate rotational malalignment. For intraarticular pathology, surgeons must address joint subluxation and significant bone loss. Posterior or anterior knee dislocations often necessitate constrained or hinged implants, particularly when preoperative range of motion is less than 80 degrees or when extensive distal femoral resection is required for extension. Medial hardware can typically be removed during the primary TKA approach, whereas lateral hardware may require staged removal. In the stiff knee, a systematic medial release—including the medial collateral ligament if necessary—is essential for adequate exposure.
Conclusion: Successful TKA in posttraumatic cases depends on precise deformity analysis and a low threshold for using constrained components. While technically demanding and associated with higher complication rates than primary TKA, adherence to established alignment principles and careful soft tissue management can achieve stable, functional results.
