Mosaic Osteochondral Autograft Transplantation Versus Bone Marrow Stimulation Technique as a Concomitant Procedure With Opening-Wedge High Tibial Osteotomy for Spontaneous Osteonecrosis of the Medial Femoral Condyle.

Purpose: To evaluate the effects of osteochondral autograft transplantation (OAT) mosaicplasty as a concomitant procedure with opening-wedge valgus high tibial osteotomy (HTO) for spontaneous osteonecrosis of the medial femoral condyle (MFC) on clinical outcomes and cartilage status in comparison with bone marrow stimulation (BMS) by drilling, and to assess the relation between lesion size and postoperative cartilage status.

Methods: Fifty-eight patients with spontaneous osteonecrosis of the MFC were treated with opening-wedge HTO and a concomitant procedure of BMS (28 patients) or OAT (30 patients). Clinical evaluation was carried out using the Knee Society Score at postoperative 2 years. Postoperative status of articular cartilage was assessed by arthroscopy according to the International Cartilage Repair Society (ICRS) grade at the time of plate removal.

Results: The Knee Society Score objective score and function score were improved at postoperative 2 years compared with preoperative value in both groups, but no significant difference was found between the 2 groups. According to the ICRS overall repair grade, cartilage status was rated as normal or nearly normal (ICRS overall score ≥8) in 41% of the BMS group and 90% of the OAT group. The results suggested that cartilage repair in OAT was significantly better than that in BMS (P = .0015). Furthermore, the BMS group revealed that repair with normal or nearly normal was observed in all less than 4 cm of lesion size, whereas the OAT group exhibited that repair with normal or nearly normal was independent of lesion size.

Conclusions: This study suggested that OAT is superior to BMS as a concomitant procedure with opening-wedge valgus HTO for spontaneous osteonecrosis of the MFC in the success of cartilage repair. However, clinical outcomes were not significantly different between these 2 procedures. When treating the lesion larger than 4 cm by joint-preserving surgery, OAT mosaicplasty is recommended as a concomitant procedure with HTO.

Level Of Evidence: Level III, therapeutic case-control study.