Neutral Ring Fixation for High-Risk Nonplantigrade Charcot Midfoot Deformity

Background: Charcot foot arthropathy negatively impacts the health-related quality of life (HRQL) of affected individuals. The disease process often is responsible for the development of significant deformity and disability, often progressing to lower extremity amputation. Many patients are morbidly obese, immunocompromised, and have complex wounds with underlying bony infection or poor bone quality, making operative correction and internal fixation problematic. Methods: Using a prospective clinical algorithm, 26 consecutive diabetic adults with multiple diabetic co-morbidities, including morbid obesity, had operative correction of nonplantigrade Charcot midfoot deformity at the midfoot level. Correction was maintained with a neutrally applied three-level ring external fixator. Average body mass index was 38.31 ± 12.51. Nineteen patients used insulin. Fourteen had open wounds with underlying osteomyelitis. The altered relationship between the forefoot and hindfoot was measured as 14.04 ± 31.09 degrees in the anteroposterior axis, and 16.70 ± 17.47 degrees in the lateral axis before surgery. Surgery included Achilles tendon lengthening, excision of infected bone, correction of the multiplanar deformity, and culture-specific parenteral antibiotic therapy. Results: At a minimum 1-year followup, 24 of 26 patients were ulcer and infection free and able to ambulate with commercially-available depth-inlay shoes and custom accommodative foot orthoses. One patient died of unrelated causes, and one had transtibial amputation for persistent infection. Four developed recurrent plantar ulcers, which resolved with excision of underlying bony prominences. There were two stress fractures through olive wire pin sites, one requiring intramedullary nailing. The radiographic anteroposterior axis was corrected to 3.12 ± 9.42 degrees, and lateral to 10.42 ± 11.86 degrees after surgery. Conclusions: Morbidly obese diabetic individuals with multiple co-morbidities complicating severe Charcot foot deformity can achieve correction of midfoot deformity after operative correction of the deformity and maintenance of that correction with a neutrally applied ring external fixator.