Adult acquired flexible flatfoot, treated by calcaneocuboid distraction arthrodesis, posterior tibial tendon augmentation, and percutaneous Achilles tendon lengthening: a prospective outcome study of 20 patients

Abstract

Background: Several methods for the treatment of acquired flexible flatfoot have been described.

Patients and methods: We followed the outcome of calcaneocuboid distraction arthrodesis with lengthening of the lateral column prospectively in 20 patients (20 feet). The mean age of the patients was 55 (30-66) years and 16 were women. The lateral column lengthening was combined with percutaneous lengthening of the Achilles tendon and augmentation of the posterior tibial tendon in all patients. Fixed forefoot supination, hallux valgus, and/or symptomatic arthrosis, were corrected with arthrodesis of the first cuneiform-metatarsal joint (n = 8) and arthrodesis of the naviculocuneiform joint (n = 2). The Foot Function Index (FFI) and American Orthopedic Foot and Ankle Society (AOFAS) Clinical Rating Index hindfoot score (CRI) were completed preoperatively and at follow-up. Follow-up time was 25 (13-39) months. All patients were physically examined at follow-up at the outpatient clinic, and the overall satisfaction rate was registered. Standardized weight-bearing radiographs were taken preoperatively and at follow-up. The lateral and dorsoplantar talometatarsal angle was measured, together with the ground-navicular distance.

Results: At follow-up, 17/20 feet had complete relief of pain or only minor symptoms. The overall patient satisfaction rate was excellent or good in 15 patients and 17 patients reported an increase in daily and/or recreational activities. 3 patients complained of pain at the distraction site and/or cuboid-MT5 joint, without signs of arthrosis. All but 1 patient would have chosen to undergo the same procedure given the same circumstances. The improvement in both the FFI and CRI was statistically significant. On radiographic examination, the lateral and dorsoplantar talometatarsal angle and the ground-navicular distance improved significantly. Nonunion developed in 2 patients and united after bone grafting. 3 patients had either paresthesia or anesthesia in the distribution area of the sural nerve.

Interpretation: We found good short-term results after calcaneocuboid distraction arthrodesis, percutaneous tendon Achilles lengthening, and medial soft tissue augmentation for the treatment of degenerative/acquired flexible flatfoot. Pain or discomfort along the lateral aspect of the foot is the most common and worrying postoperative complaint.