Early results of total knee arthroplasty with a low contact stress anteroposterior glide.

PURPOSE To present early results of 400 consecutive low contact stress (LCS) anteroposterior (AP) glide total knee arthroplasties (TKAs) performed by a single surgeon. METHODS 304 consecutive patients aged 30 to 96 (mean, 66) years underwent 400 TKAs using LCS AP glides performed by a single surgeon. Only patients with an intact posterior cruciate ligament, a fixed flexion deformity of <15 degrees, and a valgus deformity of <15 degrees were included. Patients were assessed pre- and post-operatively using the American Knee Society (AKS) and Hospital for Special Surgery (HSS) scores. Range of motion was measured using a goniometer. AP and lateral radiographs were assessed for radiolucencies and osteolysis. RESULTS The mean follow-up period was 4.2 (range, 1-8) years. The mean fixed flexion improved to 1 from 11 degrees and the mean active flexion improved to 120 from 111 degrees. Both AKS and HSS scores improved significantly. There were 28 anterior soft tissue impingements; 9 of them were in the first year of the study. Thereafter, the anterior lip of the bearing was modified and any offending osteophytes, soft tissue, or fat pads were excised. Of 39 (10%) knees that underwent re-operation (16 were due to anterior soft tissue impingement), 20 (5%) did not require change of the AP glide bearing and the remaining 19 were converted to a rotating platform bearing. No patellar baja was noted after fat pad excision. No patient had catastrophic wear or failure of the polyethylene bearing. The survival rate of the AP glide bearing was 95%. CONCLUSION The early-to-mid-term outcomes of the LCS AP glide TKA are promising.