Resolution of Fixed Flexion Contracture Following Kinematically Aligned Manual Total Knee Arthroplasty Without Raising the Joint Line

Background Persistence of fixed flexion contracture (FFC) following total knee arthroplasty (TKA) is a common occurrence, resulting in poor postoperative outcomes. Soft tissue releases and distal femoral resection have been previously studied in attempts to address this issue. There is a scarcity of literature on the resolution of FFC following primary kinematically aligned (KA) manual TKA without raising the joint line. In this study, we evaluated post-operative range of motion (ROM) in patients with a preoperative FFC following primary KA TKA without raising the joint line. Methods Eighty-five patients with preoperative FFC who underwent a primary KA TKA without distal femoral resection by a single arthroplasty-trained surgeon were identified. Demographics and pre-operative range of motion were obtained. Primary outcomes included post-operative range of motion at 6-weeks and one-year. Secondary outcomes included infection, revision rates, manipulation under anesthesia, and wound complications. Results A total of 85 patients were included, with an average pre-operative extension of 5.5° (std dev, 2.2°). Of the 85 patients, 5 had a flexion deformity within 5° of full extension, with the other 80 patients having extension ≥5° to 20°. Post-operatively, 21.2% and 5.9% of patients had a flexion contracture at 6-weeks and one-year respectively. Average post-operative extension at 6-weeks was 1.5° (std dev, 4.1°) and 0.5° (std dev, 2.3°) at one-year. Conclusion In this study, we found improvement in flexion deformity at 6-weeks and 1-year following primary KA TKA without raising the joint line. There were two cases of manipulation under anesthesia for post-operative joint stiffness.