[Arthroscopic therapy of osteochondrosis dissecans of the talus--follow-up with a new "Ankle Score"]

Abstract

Introduction: Since the advent of operative ankle arthroscopy specific treatment of osteochondritis dissecans of the talus underwent rapid progress. Besides optimizing well-known methods as drilling, spongeous plastic, curettage or refixation of dissecates new trends go to transplantation of cultivated cartilage and osteochondral allografts. Previous follow-up examinations suffer on the one hand from partially small numbers of cases, on the other hand comparisons are difficult because so far no rating system of the function of the upper ankle does exist.

Material and methods: Within three years 34 patients underwent arthroscopic treatment of osteochondritis dissecans of the talus, 16 with percutaneous drilling, 12 spongeous plastics, three refixations and three curettages. The average age of the 22 men and 12 women was 25 years (11-48 years). A newly developed score system and a follow up MRI was used in a follow-up of 29 of the patients. Up to 100 points are given in the categories pain, stability/insecurity, efficiency/painfree walking distance, gait, differences in circumference, motility and power.

Results: 27 of the 34 patients had a trauma history. 20 lesions were localized at the lateral talus, they all had a trauma history. In 7 of the 14 lesions at the medial part of the talus there was no evidence of trauma. The 29 patients in the follow-up achieved an average of 87 points, the 16 patients after K-wire drilling 85 points and the 12 patients after spongeous plastic 90 points. Deductions were noted likewise in the subjective and objective parameters. 100 points were reached by 4 patients.

Discussion: Cultured chondrozytes and osteochondral grafts are new trends in treatment of osteochondritis dissecans while arthroscopically controlled spongeous plastic after curettage and K-wire drilling represent the main component of early stages with intact or partially fractured cartilage surface. Results of K-wire drilling are negligible worse than those of spongeous plastic, which is attributed to a generous perforation of the sclerosis. This is contributed to an improved preoperative diagnosis with MRI.