[Treatment of hindfoot instability in Charcot foot using a hybrid technique of internal and external fixation]. / Behandlung von Rückfußdestruktionen beim Charcot-Fuß durch Hybridtechnik mit interner Osteosynthese und Ringfixateur.

ABSTRACT

OBJECTIVE: The main problem of patients with Charcot foot is their inability to off-load. Therefore the risk of internal fixation failure is increased, especially in hindfoot instability (Sanders type IV) with osteonecrosis of the talus. Combination of internal and additional external fixation guarantees the reconstruction and improves surgical outcome. The main objective of this surgery is to obtain a resilient, plantigrade foot that is shoeable in custom-made orthopedic shoes. INDICATIONS Charcot foot with instable collapse of the hindfoot with or without fragment dislocation, with or without (noninfected) ulceration not shoeable in custom-made orthopedic shoes. CONTRAINDICATIONS Very poor general condition, non-reconstructible peripheral vascular disease, deep infection and defects in the region of surgery which makes amputation nescessary, and poor patient compliance. SURGICAL TECHNIQUE Excision of the distal fibula and removal of the destroyed talus body using a lateral approach. Medial approach to remove the medial malleolus. Tibiocalcaneal fusion using screws for internal fixation. Fusion of the talus head to the anterior tibia. Ilizarov external fixateur to stabilize the internal fixation. POSTOPERATIVE MANAGEMENT Off-loading for 3 months, then CT scan to verify bony fusion and according to the findings stepwise weight-bearing in a cast or walker over 4-6 weeks. Then custom-made orthopedic shoes with a high shaft and insoles for neuropathic patients and full weight-bearing. RESULTS: In a retrospective cohort study, 14 of 16 patients could be fitted in custom-made shoes after undergoing tibiocalcaneal fusion. During follow-up, 2 patients required below-knee amputation, 3 patients had stress fractures of the tibia, one related to a pin track infection. All patients had a bony fusion of calcaneus and tibia; 10 of 16 patients had fusion of midfoot/talus head and the distal tibia. The 10 patients who had an ulcer before surgery could be healed. In 1 patient, a heel ulcer developed due to talipes calcaneus.