MATERIALS AND METHODS: Eighteen patients (16 males, 2 females, average age 52 years old) were found to have full-thickness cartilage lesions at arthroscopy, as well as a missing medial or lateral meniscus. The articular cartilage lesion size averaged 411.8mm² in size (range 100mm² to 1650mm²). The surgical technique included debridement of the lesions, morselization with an awl, and harvest of articular cartilage and cancellous bone from the intercondylar notch, followed by formation of a paste in a graft morselizer. The paste graft was then impacted into the morselized lesion. Meniscal allografts were placed prior to the final impaction of the paste by the technique previously described by the author. High tibial osteotomy was performed from the medial incision made for the meniscal allograft in an oblique fashion. A resorbable Bionx/Stone wedge was then impacted into the osteotomy site with either autogenous bone graft or bone from the meniscal allograft. No hardware was required. All patients were kept non-weight bearing for four weeks and used a continuous passive motion machine for six hours each day. Follow-up exam period ranges from one to thirty-four months. Nine patients underwent second-look arthroscopy with biopsy for histological analysis and collagen typing of the grafted defect.

Articular cartilage lesion, medial femoral condyle.	Site of healed articular cartilage paste graft, 7 months post-operative.

RESULTS: Clinical data has demonstrated that pain scores improved on an average from 2.3 to 0.7 on a scale of 0 to 3 (0=no pain, 3=severe pain). Swelling, giving way, locking and difficulty with stairs also showed improvement. The surgical appearance of the lesions at second-look arthroscopy has shown well-healed, smooth surfaces, with slight fibrillation in three patients. The appearance of the biopsies showed 3 to be purely hyaline, 4 to be a mixture of hyaline with some fibrocartilage and 2 to be mostly fibrocartilage. Collagen typing showed a mixture of type I and type II collagen. The meniscal allografts have demonstrated a well-healed appearance, with two subjects experiencing re-tears which were subsequently repaired. In the six patients receiving a high tibial osteotomy, all showed corrected alignment ranging from 4 degrees of varus to 0 degrees of valgus. One patient lost correction in the early postoperative period and the osteotomy was revised. There were no complications.

Hole placement for meniscal allograft insertion.	Insertion and positioning of meniscal allograft.	Inside-out suturing of meniscal allograft.

DISCUSSION: Articular cartilage paste grafting is an effective way of reducing pain and inducing healing in arthritic lesions. By correcting biomechanical alignment and replacing the meniscus it is hoped that patients will experience greater long-term pain relief and improved function. A combined technique of articular cartilage grafting, meniscal allografting and medial opening wedge osteotomy may provide a temporizing biological approach to predominantly unicompartmental arthritis. When performed simultaneously, the morbidity is low and the pain relief appears to be excellent in the short term.

Opening medial tibial osteotomy.

Implanting the Bionx/Stone resorbable osteotomy wedge.