A recent one-step arthroscopic technique based on bone marrow–derived cell transplantation has achieved good results in repairing osteochondral lesions of the talus (OLTs), overcoming some of the drawbacks of older techniques. To report the results after 4 years of a series of patients who underwent a one-step repair of osteochondral lesions of the talar dome, as well as the capability of magnetic resonance imaging (MRI) using a T2-mapping sequence to predict the clinical outcome. Case series; Level of evidence, 4. Forty-nine patients (age [mean ± SD], 28.08 ± 9.51 y) underwent a one-step repair of OLTs. Patients were evaluated clinically by American Orthopaedic Foot and Ankle Society (AOFAS) scores and radiographs and underwent MRI preoperatively and during postoperative follow-ups at predetermined times. In all patients, the cells were harvested from the iliac crest, concentrated, and loaded on a scaffold that was implanted arthroscopically. The overall AOFAS score (mean ± SD) improved from 63.73 ± 14.13 preoperatively to 82.19 ± 17.04 at 48 ± 6.1 months (P < .0005), with best results at the 24-month follow-up. A significant decrease in the clinical score was observed between 24 and 36 months postoperatively (P = .001) and between 24 and 48 months (P < .005). The T2-mapping analysis showed regenerated tissue with T2 values of 35 to 45 milliseconds, similar to hyaline cartilage, in a mean of 78% ± 16% of the repaired lesion area. The time between the occurrence of trauma and surgery was found to negatively affect the clinical outcome at the latest follow-up; patient’s age and lesion size influenced the early clinical results but did not affect the outcome at final follow-up. The stability of clinical results over time and the percentage of tissue with values similar to hyaline cartilage evidenced by MRI T2 mapping showed a tendency to correlate at the last follow-up (r = 0.497, P = .06). One-step repair of OLTs had good clinical results that were durable over time, even though there was a slight decrease in AOFAS score at the latest follow-up. The quality of the regenerated tissue detected by MRI T2 mapping directly correlated with the clinical results.

Background: Ideal treatment of osteochondral lesions of the talus is still controversial. Although good clinical and histologic results have been reported for the knee, long-term results have not been reported for autologous chondrocyte implantation in the ankle. Furthermore, magnetic resonance imaging T2 mapping is becoming an increasingly used method for noninvasive assessment of repair tissue in the knee, but no experience on the ankle has been reported. Hypothesis: The 10-year clinical results of autologous chondrocyte implantation in the treatment of osteochondral lesions of the talus has clinical efficacy comparable with the long-term efficacy of autologous chondrocyte implantation in the knee. A secondary hypothesis is that magnetic resonance imaging T2 mapping may provide noninvasive assessment of the repaired tissue quality in the ankle. Study Design: Case series; Level of evidence, 4. Methods: Between 1997 and 1999, 10 patients (age 25.8 6 6.4 years) with an osteochondral lesion of the talus were treated with autologous chondrocyte implantation. The mean size of the lesions was 3.1 cm2 (range, 2.2-4.3 cm2). All patients were evaluated clinically (American Orthopaedic Foot and Ankle Society score), radiographically, and by magnetic resonance imaging preoperatively and at established intervals up to a mean follow-up of 119 6 6.5 months. At the final follow-up, magnetic resonance imaging was graded with the Magnetic Resonance Observation of Cartilage Repair Tissue scoring system and T2-mapping evaluation in 6 cases. Results: Before surgery, the mean American Orthopaedic Foot and Ankle Society score was 37.9 6 17.8 points, while at final follow-up it was 92.7 6 9.9 (P <.0005). Magnetic resonance imaging showed well-modeled restoration of the articular surface. The regenerated cartilage showed a mean T2-mapping value of 46 microseconds (range, 34-50), with no significant difference compared with that of healthy hyaline cartilage. Conclusion: The results of autologous chondrocyte implantation in the ankle joint are comparable with those in the knee as demonstrated by the significant clinical improvement, hyaline cartilage repair, and the durability of the results. Integration of both T2 mapping and Magnetic Resonance Observation of Cartilage Repair scoring permitted adequate evaluation of the repair site in the ankle.