Cartilage repair evolution in post-traumatic osteochondral lesions of the talus: from open field autologous chondrocyte to bone-marrow-derived cells transplantation.

The aims of this study are to describe evolution in cartilage repair from open field autologous chondrocyte implantation to regeneration by arthroscopic bone-marrow-derived cells (BMDCs) "one step" technique; to present the results of a series of patients consecutively treated and to compare in detail the different techniques used in order to establish the advantages obtained with the evolution in cartilage regenerative methods. 81 patients (mean age 30±8 years) were evaluated in this study. Patient assessment included clinical AOFAS score, X-rays and MRI preoperatively and at different established follow-ups. All the lesions were >1.5 cm(2) and received open autologous chondrocyte implantation (10 cases), arthroscopic autologous chondrocyte implantation (46 cases), and "one step" arthroscopic repair by BMDC transplantation (25 cases). For arthroscopic repair techniques a hyaluronic acid membrane was used to support cells and specifically designed instrumentation was developed. Patients of all the three groups underwent a second arthroscopy with a bioptic cartilage harvest at 1 year follow-up. Mean AOFAS score before surgery was 57.1±17.2 and 92.6±10.5 (P<0.0005) at mean 59.5±26.5 months. A similar pattern of AOFAS improvement in results was found in the three different techniques. Histological evaluations highlighted collagen type II and proteoglycan expression. The cartilage repair techniques described were able to provide a repair tissue which closely approximates the characteristics of the naive hyaline cartilage. Evolution in surgical technique, new biomaterials and more recently the use of BMDCs permitted a marked reduction in procedure morbidity and costs up to a "one step" technique able to overcome all the drawbacks of previous repair techniques.