A Predictive Classification of Charcot Arthropathy of Foot and Ankle

Abstract

Category: Diabetes; Other Introduction/Purpose: Charcot arthropathy of foot and ankle is a devastating, chronic and progressive destruction of bone and joint integrity affecting one or more joints. It is commonly associated with diabetes mellitus and is characterized by joint subluxations, dislocation, and pathological fractures in patients with peripheral neuropathy and results in a debilitating deformity, possibly leading to ulceration and amputation.Many classification systems exist for charcot arthopathy of foot and ankle. However, there is still lack of consensus regarding best classification. We are proposing a new classification for charcot arthropathy of foot and ankle based on our experience of large cohort of charcot patients. Our classification can guide treatment and prognosis of diabetic charcot arthropathy of foot and ankle, which we are following for the last decade. Methods: Patients with post-acute charcot who presented at our institution from January 2004 to October 2019 were reviewed and were further classified anatomically into Type I and Type II based on plain radiographs. Type I was characterized by charcot affection of one region. Regions were categorized anatomically as a modification of both Brodsky and Schon classifications into: ankle, Lisfranc (tarsometatarsal), naviculocuneiform, forefoot, and hindfoot which includes one of the following: talonavicular joint, calcaneocuboid joint or calcaneus. Type II was characterized by affection of more than one region like peritalar, perinavicular, transverse tarsal or any other combination. Peritalar complex involves at least two joints of the following: ankle, subtalar, and talonavicular. The perinavicular type includes talonavicular and naviculocuniform or tarsometatarsal and naviculocuniform, while the transverse tarsal involves the calcaneocuboid and talonavicu-lar. Both types were further classified into four stages according to the stability, deformity and associated mechanical ulcers. (Table 1) Results: 235 patients (242 feet) were presented with diabetic charcot arthropathy. Mean age was 56 years (range 22-84). Follow- up ranged from 6 months to 10 years, with a mean of 3.3 years.Types IA and IIA were managed conservatively. All patients in Type IIB, IC, IIC, ID, IID and the majority of type IB received fusion surgery to achieve stability and correction of deformity. Stage IB ankle were fixed, while IB lisfranc were observed, and fixed if transformed to IC.Type II D had the highest complication rate in the form of: infection, nonunion, nail protrusion, implant failure, revision including exostectomy after full union and recurrence of ulcer in midfoot 3-4 years after surgery. Five patients ended up with amputation, and all were stage IID. Conclusion: For post-acute charcot, stage A have the best prognosis and can be managed conservatively provided good diabetes control.Type IB can be managed conservatively but when the ankle is affected in type IB, it is better to be elected for surgery. When charcot affects the Lisfranc joints, it is usually stable unless the lateral column is affected.All cases of type IIB, IC and IIC, ID, IID should receive surgery to achieve stability, correction of deformity and prevent complications.Mechanical ulcer (stage D) carries the worst prognosis and highest complication rate. Type IID might predict the risk of amputation