Talonavicular and subtalar joint fusion through
a medial incision (modified triple arthrodesis) has become an increasingly
popular technique for treating symptomatic flatfoot deformity caused
by posterior tibial tendon dysfunction. The purpose of this study was to look at its clinical and radiological
mid- to long-term outcomes, including the rates of recurrent flatfoot
deformity, nonunion and avascular necrosis of the dome of the talus. A total of 84 patients (96 feet) with a symptomatic rigid flatfoot
deformity caused by posterior tibial tendon dysfunction were treated
using a modified triple arthrodesis. The mean age of the patients
was 66 years (35 to 85) and the mean follow-up was 4.7 years (1 to 8.3).
Both clinical and radiological outcomes were analysed retrospectively. In 86 of the 95 feet (90.5%) for which radiographs were available,
there was no loss of correction at final follow-up. In all, 14 feet
(14.7%) needed secondary surgery, six for nonunion, two for avascular
necrosis, five for progression of the flatfoot deformity and tibiotalar
arthritis and one because of symptomatic overcorrection. The mean
American Orthopaedic Foot and Ankle Society Hindfoot score (AOFAS
score) at final follow-up was 67 (between 16 and 100) and the mean
visual analogue score for pain 2.4 points (between 0 and 10). In conclusion, modified triple arthrodesis provides reliable
correction of deformity and a good clinical outcome at mid- to long-term
follow-up, with nonunion as the most frequent complication. Avascular
necrosis of the talus is a rare but serious complication of this
technique. Cite this article:
