Long-term Outcome of Charcot Foot Treatment

Charcot arthropathy is a limb-threatening condition leading to foot collapse and subsequently to below the knee amputation in around 7 % of patients. The long-term complications of both conservative and surgical treatment have not been systematically investigated. We suspect that foot collapse can be predicted by radiologic variables during radiologic workup upon admission.

The goal of the treatment of Charcot arthropathy (CA) is to maintain a plantigrade foot. However, collapse of the longitudinal arch with subsequent plantar exostoses often occurs. A medium-term consequence is, limb loss in 7–10 % of cases. To diagnose CA, patients must suffer from polyneuropathy, 75 % of which is caused by diabetes mellitus. Approximately 50 % of patients with CA can be treated conservatively with temporary immobilization during disease activity and then with the fitting of orthopedic shoes once CA is inactive. The remaining 50 % require surgical correction. Recently, the Technical and Neuro-Orthopedics Unit, with some cooperation from Balgrist University Hospital Foot and Ankle Unit, has shown that the clinical course does not differ between diabetic and non-diabetic CA with conservative treatment. It has also been shown that with treatment in a tertiary referral center, the loss of the limb in both the surgical and conservative treatment groups is around 7 % in the medium term.

Furthermore, a high complication rate of 50 % in the actually healthy opposite foot was described. We were able to define advanced peripheral arterial disease as a risk factor for treatment failure in CA with osteomyelitis. It is unclear which complications occur in the case of purely conservative therapy and with surgical therapy beyond 5 years and whether there are particular risk factors for those complications. It is also postulated that calf muscle shortening might be the underlying cause of foot collapse in CA but it is unclear whether there are radiological parameters that can predict the development of foot collapse. Thus, the initial goal of this project is to define (over the long-term > 5 years) the rate of preserved extremities and complications in the case of conservative and surgical therapy.

The second goal is to investigate the hypothesis that foot collapse can be predicted based on radiological parameters suggesting calf muscle shorting (especially hindfoot confi guration). There will be two more substudies: one that will investigate whether in non-diabetic CA, the severity of fatty infiltration is more common compared with non-diabetic patients with polyneuropathy but without CA. This was demonstrated for diabetic CA patients at an earlier stage and might allow earlier diagnosis and treatment. The second sub-study will investigate whether the Roger's severity stages of CA correlate with the number of limbs lost. This result will allow us to inform patients more precisely of their expected treatment outcome which could increase adherence to offloading.