Charcot's foot is a complication of diabetes that almost always occurs in those with peripheral neuropathy (nerve damage). When neuropathy is present, the bones and joints in the foot do not have normal protective sensations like pain. Absence of normal protective pain mechanism can cause overloading of the feet and lead to stress fractures developing in the bones of the feet. As the patient continues to walk, unabated, stress fractures become complete fractures and accompanying joint subluxations lead to foot deformities.
Many patients do not know of the existence of Charcot's arthropathy till a foot deformity develops. The affected foot is almost always neuropathic and devoid of vibration and other modalities of sensation. The foot is often swollen, red and warmer as compared to the other foot. A deformity gradually develops as fractures displace and joints dislocate due to disintegration of ligaments. Arches of foot collapse and the foot goes into a rocker bottom deformity.
Rest and stabilization of the foot, preventing further damage is the cornerstone to management. Prevention of joint destruction and foot deformity should be the goal in all neuropathy cases. A PTB or a CROW'S BOOT will help to offload weight off the involved, insensate foot, preventing further damage. Upon early recognition of Charcot's foot, a total contact cast is applied to relieve pressure and to prevent further deformity. Cast needs periodically changes until there is no temperature difference between the two feet.
Bisphosphonates, a medicine taken in tablet form has been shown to be a useful adjunct in the management of Charcot's foot.
Ulcers commonly develop at pressure points on a Charcot's foot due to combination of neuropathy; microangiopathy and pressure. Infected ulcers require debridement before treatment in a total contact cast.
Common deformities of the foot in Charcot's
⇒Ankle, subtalar and mid-foot arthritis
⇒Bony exostosis and prominences
⇒Mid-foot fusion and reconstruction using special metal-work using titanium plates and locking screw system.
⇒Triple arthrodesis-means fusing three joints -namely sub-talar, talo-navicular and calcaneo-navicular joints. When damage to several joints across the ankle takes place, a triple fusion is done.
⇒Pan-talar arthrodesis with locked nails or locking plates: means fusing the ankle and subtalar joints.
⇒Removal/re-fashioning bony prominences to prevent ulcer formation or allow ulcer healing when one occurs.
Top picture showing midfoot collapse with prominent bone. Bottom picture on left showing midfoot-reconstruction. On right side, X ray showing mid and forefoot reconstruction.
Top picture showing a 'boat like' or rocker bottom in centre of foot. Bottom picture showing destroyed mid-foot region.
Operative picture of a charcot's foot in stages, removal of bony prominences, correcting the arch, and then fixing the foot in a corrected position with special plates .