Patellofemoral complications after posterior-stabilized total knee arthroplasty: A comparison of 2 different implant designs

We conducted a retrospective review of 2 consecutive series of posterior-stabilized total knee arthroplasties (TKAs) to evaluate patellofemoral complications, in particular, significant patellofemoral crepitance or patellar clunk syndrome. Twenty posterior-stabilized Axiom PSK (Wright Medical Technology, Arlington, TN) TKAs (group 1) were compared with 20 posterior cruciateNsacrificed Advance medial pivot (Wright Medical Technology, Arlington, TN) TKAs (group 2). The average age in group 1 was 69 years and in group 2 was 70 years. Preoperative valgus alignment in group 1 was 7.5° and in group 2 was 1.3°. Postoperative valgus alignment for the 2 groups was 4.8° and 5.3° valgus. Postoperative patellar tilt for the 2 groups was 0.9° lateral tilt and 8° lateral tilt. Patellofemoral signs of crepitance ≥2+ and significant box impingement complaints of either snapping or clunking decreased significantly postoperatively from 5 of 20 (25%) in group 1 to 0 of 20 in group 2 (P=.0079). Copyright 2002, Elsevier Science (USA). All rights reserved.