Osteotomy for treating knee osteoarthritis.

BACKGROUND: Patients with unicompartmental osteoarthritis of the knee can be treated with a correction osteotomy. The goal of the correction osteotomy is to transfer the load bearing from the pathologic to the normal compartment of the knee. A successful outcome of the osteotomy relies on proper patient selection, stage of osteoarthritis, achievement and maintenance of adequate operative correction.

OBJECTIVES: To assess the effectiveness and safety of an osteotomy for treating osteoarthritis of the knee.

SEARCH STRATEGY: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE (Current contents, Health STAR) were searched up until October 2002 for controlled clinical trials. The reference lists of publications in the identified trials were also screened.

SELECTION CRITERIA: Extracted studies were included in the final analysis if they met the pre-defined inclusion criteria: 1) a randomised controlled clinical trial or a controlled clinical trial 2) all patients had unicompartmental osteoarthritis of the medial or lateral compartment of the knee 3) the intervention in one of the studied groups was a high tibial osteotomy or a distal femoral osteotomy.

DATA COLLECTION AND ANALYSIS: Two reviewers independently selected the trials, assessed the methodological quality using a validated tool and extracted the data. The planned analysis was to pool the results where appropriate, however, due the heterogeneity of the studies, pooling of the outcome measures was not possible. Results are described for each study and presented as a best evidence synthesis.

MAIN RESULTS: Following the search strategy and applications of selection criteria, eleven studies were included in this review. All the studies concerned a valgus high tibial osteotomy (HTO) for medial compartment osteoarthritis of the knee. Four studies compared two techniques of HTO. One study compared HTO alone versus HTO with additional treatment. Four studies compared within the same type of HTO, different per-operative conditions (two studies) or two different types of post-operative treatment (two studies). Two studies compared HTO with unicompartmental joint replacement. No study compared an osteotomy with conservative treatment. Most studies showed improvement of the patient (less pain and improvement of function scores) after osteotomy surgery, but in the majority of the studies there was no significant difference with other operative treatment (other technique of HTO/ unicompartmental joint replacement). Overall, the methodological quality was low.

AUTHORS' CONCLUSIONS: Based on 11 studies, of which 6 were high quality, we conclude that there is silver level evidence that valgus HTO improves knee function and reduces pain. There is no evidence whether an osteotomy is more effective than conservative treatment and the results so far do not justify a conclusion about effectiveness of specific surgical techniques.