Mosaicplasty for osteochondritis dissecans of the knee: About 4 cases

Osteochondritis dissecans (OCD) of the femoral condyles is a subchondral bone necrosis, resulting in osteochondral fragmentation that causes joint dysfunction. Mosaic grafting consists of harvesting osteochondral grafts from a donor site and transferring them to the osteochondral defect. The objective of our study was to evaluate the results of mosaicplasty as a treatment for osteochondritis dissecans of the knee. This is a retrospective study of 04 cases of osteochondritis dissecans of the knee in the department of traumatology and orthopedics at the University Hospital Oujda, Morocco. The average preoperative IKDC functional score was 43. The lesions were classified according to Cahill's classification in zone 2 and 3, and according to Harding's classification in zone B and C. According to Bedeouelle's classification, the evolutionary stage was divided into one stage IIb case, two stages III, and one stage IV.MRI revealed two stage II cases and one case for each of the stages IV and V according to Hefti's classification. Our surgical treatment consisted of osteochondral reconstruction of the injured area by mosaicplasty. A first arthroscopic step allows us to evaluate the size and depth of the cartilage defect. The 4 patients had an OCD grade 4 ICRS. All our mosaicplasties were performed open after a medial arthrotomy. Progressive rehabilitation was started the next day, and weight-bearing was not allowed until the sixth week. The IKDC score was 84.5. The arthroscopic "second look" showed the integration of the grafts with the edges of the healthy hyaline cartilage, creating a "golf ball" appearance. The mosaic graft is a validated cartilage restoration technique [14]. Garretson et al [15] demonstrated that the optimal and least constrained site was the margins of the superomedial trochlea. Hangody et al [18] reported in a heterogeneous series of more than 1,000 mosaic grafts: 3% morbidity, four infections and 36 hemarthroses. Gudas et al [22] compared 29 mosaic grafts and 29 microfractures for lesions with an average size of 2.7 cm2 , and found a remarkable advantage of the mosaic graft in this indication. Mosaic grafting has the advantage of being less expensive than reconstructive techniques, performed in a single surgical step, and of offering immediate restoration of the cartilage surface.