SURGICAL TREATMENT OF OSTEOCHONDRAL LESIONS OF THE TALUS BY OPEN FIELD AUTOLOGUOUS CHONDROCYTE IMPLANTATION. A 10 YEARS FOLLOW-UP CLINICAL AND MRI T2-MAPPING EVALUATION

Abstract

Introduction: Ideal treatment of osteochondral lesions of the talus (OLT) is still controversial.

Aim of this study is to review the 10 years follow-up clinical and MRI results of open field Autologous Chondrocytes Implantation in the treatment of OLT.

Methods: From December 1997 to November 1999, 10 patients, age 25.8 +/−6.4 years, affected by OLT, received open field Autologous Chondrocytes Implantation. The mean size of the lesions was 3.1 cm² (2.2 – 4.3).

All patients were evaluated clinically (AOFAS score), radiographically and by MRI pre-operatively and at established intervals up to a mean follow-up of 119+/−6.5 months. At the final follow-up MRI T2 mapping evaluation was performed. A bioptic sample was harvested in 5 cases during hardware removal 12 months after implantation.

Results: Before surgery the mean score was 37.9 +/−17.8 points, at 24 months it was 93.9 +/−8.5, while at final follow-up it was 92.7 +/−9.9 (p< 0.0005).

Bioptic samples showed cartilaginous features at various degrees of remodelling, positivity for collagen type II and for proteoglycans expression. No degenerative changes of the joint at follow-up were found radiographically.

MRI showed well-modelled restoration of the articular surface. The regenerated cartilage showed a mean T2 mapping value of 46 msec with no significant difference compared to that of normal hyaline cartilage.

Conclusions: The clinical and histological results have confirmed the validity of the technique utilized with a durability of the results over time. T2 mapping was adequate in detecting the quality of the regenerated tissue coherently with the bioptic results.