Mosaicplasty for the treatment of articular defects of the knee and ankle.

Efficacious treatment of full-thickness cartilage defects of the weightbearing surfaces is a multi-faceted challenge for the orthopaedic surgeon. Autologous osteochondral transplantation represents one solution: to bring about a hyaline or hyalinelike repair of the defected area. The current authors discuss the experimental background and their 8 years of clinical experience with the autologous osteochondral mosaicplasty. Several series of animal studies and subsequent clinical practice have confirmed the survival of the transplanted hyaline cartilage. Hyaline cartilage and fibrocartilage fill the donor sites located on the nonweightbearing surfaces and surfaces that bear less weight. Clinical scores, imaging techniques, control arthroscopies, histologic examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage. According to these investigations, femoral condylar implantations have shown good to excellent results in 92%, tibial resurfacing in 88%, patellar and/or trochlear mosaicplasties in 81%, and talar procedures in 94% of patients. The Bandi score showed long-term donor site disturbances in 3% of patients. Fifty-eight of the 68 control arthroscopies had good gliding surfaces, histologically-proven survival of the transplanted hyaline cartilage, and fibrocartilage covering of the donor sites. In the entire series, there were four deep infections and 34 painful hemarthroses after surgery. A multicentric, comparative, prospective evaluation of 413 arthroscopic resurfacing procedures (mosaicplasty, Pridie drilling, abrasion arthroplasty, and microfracture cases in homogenized subgroups) showed that mosaicplasty gave a more favorable clinical outcome in the long-term followup, than the other three techniques. Intermediate-term evaluation of the femoral condylar implantations (3-6-years followup) and talar mosaicplasties (3-7-years followup) confirmed the durability of the early results. From these encouraging results from an increasingly large series and similar results from other centers, it seems that autologous osteochondral mosaicplasty may be a viable alternative treatment of localized full-thickness cartilage damage of the weightbearing surfaces of the knee and other weightbearing synovial joints.