Isolated in-situ mosaicplasty fixation of unstable knee osteochondritis dissecans in skeletally mature patients; a combined mechanical and biological solution with excellent outcomes and a low re-operation rate.

Abstract

Unstable osteochondritis dissecans (OCD) of the knee can result in substantial morbidity; the aims of surgical management are to provide stability to the lesion and to stimulate biological healing. The aim of this study was to review the outcomes of a previously described, but uncommonly used, technique involving isolated mosaicplasty fixation of unstable knee OCD. A retrospective review of skeletally mature patients treated with in-situ mosaicplasty fixation of unstable OCD of the knee was performed. Two out of thirteen knees also underwent concomitant realignment osteotomy. Postoperative magnetic resonance imaging (MRI) and patient-reported outcome measures were reviewed. Twelve patients (13 knees) were included; there were 5 females and 7 males. The mean age at time of surgery was 22 years (range 16-32). The lesion location was lateral femoral condyle in 7 cases and medial femoral condyle in 6 cases. Follow-up MRI scans confirmed fragment healing in 12 knees (92%). One patient required further surgical intervention for ongoing symptoms and radiological non-union: the patient underwent an off-loading distal femoral osteotomy to correct valgus mal-alignment. This series describes the outcomes following an uncommonly performed, yet reproducible and effective method of fixation of unstable knee OCDs. We believe in-situ mosaicplasty fixation represents an opportunity to provide both mechanical stability and biological augmentation of OCD healing, and the series confirms that excellent results can be achieved with a low re-operation rate. Level IV.