Long-term results after operative treatment of osteochondritis dissecans of the knee joint-30 year results.

Osteochondritis dissecans (OD) mostly appears at the knee joint on the weight-bearing part of the medial femoral condyle. A multi-factorial event is most likely responsible for the triggering of OD. The aim of this retrospective study was to carry out long-term assessment of the results of operative treatment. Between 1959 and 1976, 148 patients were treated for OD by an open technique. For this purpose, a total number of 38 patients were analysed after approximately 30 years. Twenty-six patients were evaluated clinically by means of standardised questionnaires and also radiologically; 12 patients were analysed only by questionnaire. In order to verify the clinical findings and the subjective assessment, radiographs were done and analysed according the Kannus score. The Brückl score was used to evaluate the results of the OD. Twenty-four knee joints were analysed by radiographs. Sixty percent of the operated joints showed poor results in the analysis according to Kannus. Only four patients showed an excellent result by using the clinical scoring system. Nevertheless, we were able to prove a markedly higher rate of osteoarthrosis. The causal explanation for this lies in the patient selection. Most of the patients were above average age, and the OD was discovered quite late, and thus the disease had already progressed to a higher degree. In 74% of all cases, an extirpation of the osteochondral fragment was performed, whereas today there are several operative options. In our view, therefore, the need arises to conduct further follow-up examinations with comparative time spans, as well as to conduct a parallel analysis of corresponding control groups in order to evaluate the aetiology of the increased rate of osteoarthrosis.