Arthroscopic ankle arthrodesis: are results reproducible irrespective of pre-operative deformity?

Arthroscopic ankle arthrodesis is gaining in popularity. It has been shown to have a shorter time to union and less morbidity than traditional open procedures. The arthroscopic technique has been mainly used for ankles with minimal deformity. Our aim was to find out whether we could reproduce the good results of arthroscopic ankle arthrodesis in both minimally and markedly deformed ankles.

We reviewed 62 patients who underwent an arthroscopic ankle arthrodesis for end stage arthritis. The average follow up was 63 months (range 21-92 months). Patients were evaluated subjectively and objectively using the Mazur grading system. 4 patients died before final review and 3 were lost to follow-up leaving 55 patients for evaluation. The pre-operative tibiotalar angle in the coronal plane was between 26° valgus and 24° varus. We divided our patients into 2 groups based on the tibiotalar angle. Group A (n=31) had a varus or valgus deformity of less than 15 and Group B (n=24) had a deformity equal to or more than 15°.

The overall fusion rate was 91%. Fusion occurred in 29 of 31 (94%) ankles in Group A compared to 21 of 24 (88%) in Group B (p=0.64).The overall mean time to union was 10.4 weeks. The time to union in Group A was 8.8 weeks compared to 12.7 weeks for Group B (p=0.001). Using the Mazur ankle grading system, 84% of the cases in Group A had a good to excellent result compared to 79% in Group B (p=0.73). There were 2 superficial infections, 2 cases of deep vein thrombosis and 3 patients required removal of prominent screws.

We have shown that arthroscopic ankle arthrodesis yields reliable and reproducible results in a District General Hospital setting with high union rates, short time to union and low complication rates. It can be satisfactorily employed for ankles with significant deformity, although this resulted in a longer time to union. The end results remain uniformly good to excellent.