Purpose: We report a series of 46 cases of subtal instability associated or not with tibiotarsal lesions treated by Castaing ligamentoplasty between 1988 and 1999.

Material and methods: Preoperatively, symptoms were: instability, twisted ankle, recurrent ankle sprains, pain. A tarsal sinus syndrome was found in 39%. MRI was performed in all 46 patients and revealed ligamentary lesions in all case. Outcome was assessed with the Kitoaka score.

Results: At mean 5.7 years follow-up instability had resolved in 80% of the ankles. Total pain relief was noted in 63%. Physical examination demonstrated reduced motion of the subtalar joint with inversion in 43% ranging from 50% to 70% compared with healthy side, but without significant functional impact. Radiographic signs of early-stage degeneration were found in three patients. Overall outcome was very good in 82%, fair in 11%, and poor in 7%. The index of patient satisfaction was 87%.

Discussion: This series showed a correlation between body mass index greater than 26 or constitutional laxity and fair or poor results. Furthermore, longer time between the first sprain and surgical management of the residual instability led to less satisfactory final outcome. Comparison with other ligamentoplasty techniques showed similar results.

Conclusion: The Castaign procedure provides results similar to other ligamentoplasty techniques. Direct repair of the subtalar ligaments should however be preferred as the first-intention procedure, reserving Castaign ligamentoplasty for cases of failed repair.