Surgical management of severe deformity resulting from posterior tibial tendon dysfunction.

A retrospective case study format was used to evaluate the results of surgical treatment of severe deformities due to long-standing tibialis posterior tendon dysfunction. To be included in the study, the peri-talar (talonavicular) subluxation on a weight-bearing AP X-ray should have been at least 75%. This criterion limited the field to patients with long-standing, rigid, severe deformities. Surgical correction was obtained through a two-incision approach, dorsomedial and dorsolateral. Significant shortening of the medial column and extensive removal of adaptive bone formation was necessary to allow reduction of the hind- and midfoot deformity. Stable internal fixation using multiple screws was used to secure the reduction. Eleven patients, 12 feet were evaluated. The patients were evaluated using the American Orthopedic Foot and Ankle Society Ankle and Hindfoot Score as well as a questionnaire on footwear and satisfaction rating. The average score improved from 30 points pre-op to 74 points post-op (out of 100). P-value 0.0001. Pain score improved from 11/40 to 33/40. Function improved from 19/50 to 33/50. Alignment improved from 0/10 to 8/10. The radiological parameters showed an average improvement of 31 degrees in the lateral talo-1st metatarsal angle, 11 degrees in the calcaneal pitch, and 35 degrees in the AP talo-1st metatarsal angle. All three parameters were highly significant with P-values of 0.0001. Multiple complications occurred. This included two delayed unions with breakage of screws and partial loss of correction, four wound problems, two sural nerve impairments and three patients requiring hardware removal. Even though it is an extensive procedure with multiple potential complications it still offers a substantial improvement in quality of life.