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.

Introduction: Qualitative evaluation of postoperative outcome in cartilage repair techniques is an issue due to morbidity of bioptic second look. T2 mapping is becoming increasingly popular in the knee, providing information about the histological and biochemical contents of healthy or reparative tissue. Nevertheless, little is known about its applicability to the ankle due to thinner cartilage layer.

Aim of this study was to investigate the validity of T2 mapping in ankle cartilage characterization.

Materials and Methods: 20 healthy volunteers and 30 patients affected by osteochondral lesions of the talus and previously treated by different cartilage repair techniques, were evaluated by T2 mapping. Reparative procedures included microfractures, Autologous Chondrocyte Implantation (open or arthroscopic) and Bone Marrow Derived Cell’s Transplantation. DPFSE with or without fat suppression, T2FSE with or without fat suppression, 3D SPGR and T2-Mapping using a dedicated phased array coil and 1.5 T MR scanner were used as MRI acquisition protocol.

MRI results were correlated with clinical score (AOFAS) in the cases who received a cartilage reconstruction treatment.

Results: A statistically significant correlation (p< 0.05) was shown between MRI and clinical results. A reduced mean T2 value, suggestive for fibrocartilage features, was shown at repair sites in microfractures, whereas no significative differences with healthy hyaline cartilage mean T2 value, were found in other repair techniques with good to excellent clinical score.

Conclusions: T2 mapping demonstrated to be adequate in characterizing cartilage tissue in the ankle. Further studies are required to implement a tool which may over time be a valuable non-invasive alternative to bioptic evaluation.