[Tibio-talar arthrodesis: long term influence on the foot]

The aim of this study was to evaluate the long-term effect of tibiotalar arthrodesis on function, clinical and radiological tolerance, and subtalar joints.

We reviewed 37 cases of tibiotalar arthrodesis in 27 young patients who were generally manual workers. Their mean age at surgery was 46 years and mean follow-up at review was 12.8 years (range 5-26 years). Functional outcome was assessed with the Duquennoy scale. We reviewed the anterioposterior and lateral weight-bearing views as well as the lateral view in dorsal and forced plantar flexion.

Mean functional outcome was good and very good in 66% of the cases, fair in 30% and poor in one case. Total pain relief had been achieved in 45% of the cases with a mean walking distance of 1500 m without crutches. Residual mobility at last follow-up was 13 degrees for the mediotarsal joint. This mobility allowed the arthrodesed foot to adapt to gait. Radiologically, fusion had been achieved in 83% of the cases within 3 months. The overall functional score fell off proportionally with the degree of arthrodesis valgus starting at 5 degrees. Likewise pes equinus > 10 degrees led to pain and reduced motion. The subtalar joints were affected in all cases, leading to poor adaptation of the foot on uneven ground. Grade 1 osteoarthritis affected the mediotarsal joint and was more marked in case of equine fixation.

Our results are similar to those reported in the literature. We had 4 cases of nonunion in patients with risk factors previously discussed in the literature.

Arthrodesis remains a useful method for treating talocrural osteoarthritis, providing good long-term results. The position of the fixation should be 90 degrees in the sagittal plane and 0 degrees to 5 degrees valgus in the frontal plane.