Osteochondral multiple autograft transfer (OMAT) for the treatment of cartilage defects in the knee joint.

The ideal articular cartilage repair tissue should be durable and well-integrated. We have been performing osteochondral multiple autograft transfers (OMAT) since 1996 with the experience we had using carbon fiber implants. We call this technique OMAT instead of mosaicplasty because we use uniform osteochondral autografts. Osteochondral multiple autograft transfer (OMAT) was performed either by arthrotomy or arthroscopy on 12 patients (6 male and 6 female) for the treatment of cartilage defects in the knee joint. The patients ranged in age from 20 to 63 years (mean: 38 years). All had weightbearing-related pain or decrease in the range of motion. None had instability or malalignment. The average follow-up time was 4 years (range: 2 to 8 years). Clinical results were satisfactory. All of the paients were improved initially by the procedure and 85% are still pain free. The mean Lysholm knee rating score was 56 points preoperatively and 86 points postoperatively. Second-look arthroscopy (five patients) demonstrated a normal shiny appearance and color of the grafted area. We observed slight joint effusion postoperatively that disappeared in two months. There was no donor site morbidity. OMAT is a promising surgical technique for the treatment ofarticular cartilage defects. Long-term follow-up with more patients and histological and biomechanical evaluation of chondral interfaces are the subjects of our continuing study.