Surgical techniques in the performance of unicompartmental arthroplasties

The technical principles of unicompartmental knee arthroplasty (UKA) are similar to but subtly different from totalknee arthroplasty (TKA). Reestablishing the joint line of the diseased compartment and restoring the altered anterior cruciate ligament, posterior cruciate ligament, and collateral (medial and lateral) kinematics are the goals of surgery. When proper indications exist, normal knee function is possible. Instrumentation systems plus surgical expertise must provide for accurate compartment resurfacing of the femoral condyle and tibial plateau. Technical errors of malposition (rotational, varus-valgus, flexion-extension) and gap imbalance (depth of resection) will negatively affect stability, mobility, wear, and fixation with less than satisfactory clinical outcomes. Because few UKAs are performed, even by so-called experts, more attention to detail is required. Excellent long-term results can be appreciated when patient selection, prosthetic design, and surgical technique are optimal. This section addresses the key technical aspects of UKA that will affect clinical results.