Introduction: The optimal treatment of osteoarthritis of the medial compartment of the knee joint is still controversial. Optional procedures include arthroscopic knee debriedement, high tibial osteotomy, and total knee arthroplasty. In the last decade the use of unicompart-mental knee arthroplasty (UKA) for localized knee arthritis has become more and more common. This study reviews our experience with unicondylar meniscal bearing knee arthroplasty in patients with localized osteoarthritis of the medial compartment of the knee joint.
Material &
Methods: Between 2001–2004, 26 Pts. (17F, 9M; 52–74 year old, mean 63Y) underwent surgery using the Medial Oxford Unicompartmental Knee. Four of them had since been operated on their other knee, usually 1–2 years after the first UKA. The mean age at surgery was 63 years (52–74). There were 17 women and 9 males. All patients had a stable knee and their preoperative ROM was between −10 degrees to full extension and between 100 to 120 degrees of flexion. Patients were followed for 1.5 – 4 years (mean 2.5Y), and evaluated by the Knee Society Score and radiographs.
Results: 24/26 (92%) patients, including the four patients who had staged bilateral procedures of both knees, had satisfactory results, of them 16/26 (61%) had excellent results and 8/26 (31%) had good results. They were almost free of pain, and most of them had marked improvement in knee function. Similar results were observed in each of both knees of the patients who had staged bilateral unicondylar knee arthroplasty. The remaining 2 patients (8%) had fair results. A second look arthroscopy of these patients revealed a progressive development of degenerative changes of the lateral compartment in one patient, and development of degenerative changes of the patella and patellar groove in the second patient.
Conclusions: Based on this study it seems that unicondylar knee arthroplasty is a favourable procedure in patients with localised arthritis of the medial compartment. This procedure allows replacement of only the affected joint compartment with less bone loss, and therefore enables preservation of healthy tissue and bone. Recovery following surgery is fast, rehabilitation is quick and ambulation is early. The ideal patient for UKA is a relatively young patient with localized degenerative changes, who has a stable knee, a flexion contracture less than 15 degrees and a mechanical axis of less than 10 degrees from neutral for a varus knee, or less than 5 degrees for a valgus knee.