A COMPARISON OF THE SHORT-TERM RESULTS BETWEEN PCL SUBSTITUTING MEDIAL PIVOT KNEE AND NEXEN® LPS TOTAL KNEE ARTHROPLASTY

Abstract

We compared the short term follow-up clinical and radiological results after PCL substituting (PS) Medial Pivot Knee and Nexgen^® LPS total knee arthroplasty (TKA).

Seventy knees in 48 patients after TKA with PS ADVANCE^® Medial Pivot Knee (Group I) and sixty seven knees in 45 patients after TKA with Nexgen^® LPS (Group II) were evaluated retrospectively from March 2004 to May 2006. The mean follow up period was 31 months (range: 24–43 months) in group I and 32 month (range: 24–46 months) in group II. All the knees were operated by one surgeon. The evaluations included the preoperative and postoperative range of motion (ROM), Knee society score (KSS), tibiofemoral angle, and postoperative complications.

In group I, ROM increased from preoperative mean flexion contracture of 6.3° and further flexion of 116° to postoperative mean flexion contracture 1.9° and further flexion 121°, KS knee score increased from 46 to 87, KS function score increased from 37 to 83, and tibiofemoral angle changed from preoperative varus 4.0° to postoperative valgus 5.5°. In group II, ROM increased from preoperative mean flexion contracture of 13° and further flexion of 118° to postoperative mean flexion contracture 0.9° and further flexion 123°, KS knee score increased from 50 to 87, KS function score increased from 48 to 83, and tibiofemoral angle changed from preoperative varus 4.1° to postoperative valgus 5.3°. The complications were two periprosthetic patellar fracture and one failure of tibial component in group I, and one early failure of femoral component and one arthrofibrosis in group II. There was no statistical difference in radiological and clinical results between the two groups.

Minimum 2-year follow-up result of PS Medial Pivot Knee TKA was comparable to that of Nexgen^® LPS TKA and longer term follow-up would be necessary.