Club foot ankle osteoarthritis risk revealed
medwireNews: Patients treated for clubfoot have a low long-term risk for ankle osteoarthritis (OA), say Swedish researchers after studying patients aged over 60 years.
Of the 60 patients, aged an average of 64 years, with congenital talipes equinovarus, just 7.9% of 89 affected ankles showed radiographic evidence of severe OA, the team reports in the British edition of the Journal of Bone and Joint Surgery.
By comparison, 12% of affected feet had severe OA of the talonavicular joint, suggesting instead that "the ankle is resistant to degenerative forces, and that residual problems reside more in the midfoot than in the ankle," say Henrik Wallander (Gävle Hospital) and co-authors.
The patients' feet had been treated for congenital talipes equinovarus using manipulation and casting alone (n=13), alongside soft-tissue procedures (n=44), or in combination with bony procedures (n=32).
Weight-bearing foot and ankle radiographs for the patients showed that the talocalcaneal angles were significantly lower in the anteroposterior (9.6 vs 17.7°) and lateral projections (28.8 vs 37.9°) in the clubfeet than the control feet. Club feet were also significantly more likely to have medial subluxation of the navicular than unaffected feet (15 vs 34 mm).
Overall, 22% of patients had a modified Laaveg-Ponseti score over 90 points, indicating excellent function, and 28% of patients had a score of 80 to 89 points indicating good function. Thirteen percent of patients had fair function (70-79 points), and 37% scored below 70 points indicating poor function.
Of note, patients who had undergone no more than one operation on their clubfoot had a significantly higher function score than patients who had undergone two or more procedures (mean 83 vs 66 points).
There was a significant relationship between functional result and both the degree of medial subluxation of the navicular, and the talocalcaneal angle on anteroposterior projection.
Function was also significantly associated with the extent of ankle and talonavicular OA in the whole group, but further gender analysis suggested this correlation was only true in men.
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By Lynda Williams, Senior medwireNews Reporter