[The femoropatellar endoprosthesis--still of value today?]

Abstract

Purpose: Aim of this study was the examination of clinical middle- and long-term results of total femoropatellar endoprostheses type Lubinus (Link, Germany).

Method: From 1983 to 1996 12 patients (15 joints) underwent total femoropatellar joint replacement (type Lubinus, Link, Hamburg). All of them have been controlled 7.2 +/- 2.6 years (2 to 12 years) after surgery. The indication was primary osteoarthritis in 6, chondrocalcinosis in 2 and rheumatoid arthritis in 7 cases. In addition to the femoropatellar implants femorotibial endoprostheses have been used in 10 knees: 2 unicondylar medial, 1 unicondylar lateral and 7 bicondylar unicompartimental ones.

Results: According to a modified Hungerford knee rating scale 8 knees resulted excellent, 2 fair and 4 poor. One knee was excluded after revision surgery due to a loosened tibial component of a medial unicompartimental knee arthroplasty. The 4 poor outcomes resulted from femoropatellar replacements in chondrocalcinosis (2 cases), rheumatoid arthritis and osteoarthritis, (one case each), affecting the femorotibial joint as well.

Conclusions: In those cases of simultaneous femorotibial joint affection--even if this is merely slight and beginning and if the femoropatellar complaints are actually clearly dominating--the sole femoropatellar surface replacement seems to be contraindicated according to our experiences. Providing correct and strict indications this endoprosthesis can be recommended for sole femoropatellar osteoarthritis especially since loosening of endoprosthetic components was not been found in this study.