LONG TERM RESULTS OF THE PFC TOTAL KNEE ARTHROPLASTY SYSTEM. A MINIMUM 15 YEAR FOLLOW-UP AND SURVIVORSHIP ANALYSIS

Abstract

There are only a limited number of long term studies of total knee arthroplasty and few with a minimum fifteen year survivorship of a modular fixed bearing posterior cruciate-retaining prosthesis. This consecutive series of 139 total knee arthroplasties (109 patients), using the non-conforming posterior cruciate-retaining Press Fit Condylar (PFC®) system was followed for a minimum of 15 years (range 15.0 to 16.9 years). The patella were resurfaced with an all-polyethylene component in 83% of knees. The tibial component was always cemented, while a porous-coated femoral component was used in 84% of knees. Fifty-nine knees (45 patients) were followed up for a minimum of 15 years. Fifty-seven patients (70 knees) had died and five (8 knees) were too ill to assess. Survivorship of the prosthesis was confirmed for 98.6% of the prosthesis, as only two patients (2 knees) were lost to follow-up.

The mean Knee Society Score and Function Score were 96 and 78 respectively. The total incidence of radiolucent lines was 13%, with 2% around the femur, 11% around the tibia, and 0% around the patella. None of these lines were of any clinical relevance. There was no evidence of progressive radiolucent lines or component loosening, and one case of zone 4 femoral osteolysis.

There were five re-operations for any indication, of which four were for polyethylene insert wear. There was also one loose cemented femoral component after more than 15 years. The survival without need for revision for any reason was 99% at 10 years and 95.6% (worst-case scenario of 94.2%) at 15 years.

This single-surgeon series with a minimum 15 year follow-up shows that the modular fixed bearing posterior cruciate retaining total knee arthroplasty of the PFC system can provide excellent and predictable long term results in tri-compartmental arthritis of the knee.