Value of magnetic resonance imaging in the follow-up of surgically treated osteochondrosis dissecans of the talus

Aim: Our study was designed to evaluate the use of magnetic resonance imaging (MRI) in the follow-up of surgically treated osteochondrosis dissecans (OCD) of the talus. Method: We investigated 16 patients (18 joints) with OCD of the talus, surgically treated in our department between 1990 and 1997. All of them had preoperative MRI scans of the affected ankle. The mean follow-up was 40 months (8-82). All patients were evaluated by clinical examination, plain radiography and MRI using a standard protocol. Results: The clinical Bray score improved significantly from 58 preoperative to 82 postoperative. Using a visual analogue scale we saw a significant reduction of the patients pain level post-op. In 72% of the patients the preoperative MRI was able to predict the accurate stage of the cartilage. Postoperative MRI showed no more lesion in 3, intact articular cartilage in 11, and disrupted cartilage in 4 joints. There was no correllation between clinical, plain radiographical, and MRI findings postoperative. Conclusion: Arthroscopy remains the golden standard in evaluating articular cartilage. Using our data, MRI is not the method of choice in the follow-up of surgically treated OCD lesions of the talus. Postoperative use of intravenous contrast media gave no additional information. Postoperative MRI should be reserved only for symptomatic patients to gather additional information about the actual state of the OCD. Afterwards a prompt arthroscopy of the symptomatic ankle should be performed.