Three- to six-year follow-up results after high-flexion total knee arthroplasty: can we allow passive deep knee bending?

Purpose We evaluated 3- to 6-year clinical and radiological follow-up results after NexGen ® LPS-flex total knee arthroplasty (TKA). Methods A retrospective evaluation was undertaken of 218 knees in 166 patients (22 males, 144 females) who were followed up for more than 3 years after TKA. Evaluations included preoperative and postoperative range of motion (ROM) measurement, Knee Society (KS) Score, tibiofemoral angle and assessment of postoperative complications. Results TKA resulted in a significant ROM increase from a mean flexion contracture of 9° (range 0°–20°) and further flexion of 117° (range 80°–155°) to a mean flexion contracture of 2° (range 0°–10°) and a further flexion of 131° (range 95°–155°). KS knee and function scores significantly improved from 52 and 38 before surgery to 87 and 82 after surgery, respectively. The tibiofemoral angle significantly improved from varus 5.7° to valgus 5.4°. Progressive radiolucent lines around the femoral component on radiographs were observed in 30 knees (13.8%, 27 patients), and more of those knees, could squat than non-radiolucent knees (76.7 vs. 20.2%; P