Background: Efficacious treatment of chondral and osteochondral defects of weightbearing articular surfaces is a daily challenge in musculoskeletal care. Autogenous osteochondral transplantation represents a possible solution for creating hyaline or hyaline-like repair in the affected area that has a noninflammatory pathoorigin. This paper discusses the experimental background and over 15 years of clinical experience with autologous osteochondral mosaicplasty.
Methods: Several series of animal studies and subsequent clinical practice of over 1,000 mosaicplasty patients were assessed to confirm the survival of transplanted hyaline cartilage and fibrocartilage filling of donor sites located on relatively less weightbearing surfaces, as well as donor-site disturbances and morbidity. Histological evaluations of dog and horse implantations as well as several series of clinical evaluations in the human material are summarized in this paper. Clinical scores, different types of imaging techniques, second-look arthroscopies, histological examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage.
Results: Analysis of clinical scores has shown good to excellent results in 92% of patients with femoral condylar implantations, 87% of tibial resurfacements, 74% of patellar and/or trochlear mosaicplasties and 93% of talar procedures. Longterm donor-site complaints measured by the Bandi score were minor and present only in 3% of patients. 81 out of the 98 control arthroscopies represented congruent and good gliding surfaces and histologically proven survival of the transplanted hyaline cartilage as well as fibrocartilage covering of the donor sites. Complications in the entire patient group were four deep infections and four deep venous thromboses. In nearly 8% of the cases excessive intraarticular bleeding was observed in the early postoperative period, as a minor complication of the procedure. Multicentric, comparative, prospective evaluation of 413 arthroscopic resurfacing procedures (mosaicplasty, Pridie drilling, abrasion arthroplasty and microfracture cases in homogenised subgroups) demonstrated that mosaicplasty resulted in favourable clinical outcome in the long-term follow-up compared to other three techniques. Durability of the early results was confirmed in long-term evaluations both of the femoral condylar implantations and talar mosaicplasties.
Conclusions: According to our encouraging results in this increasingly large series, supported by similar findings from other centres, it seems that autologous osteochondral mosaicplasty may be an alternative for small and medium-sized focal chondral and osteochondral defects of weightbearing surfaces of the knee and other weightbearing synovial joints.