[Hindfoot amputations]

Abstract

Objective: Obtaining a durable, weight-bearing stump with minimal or no loss of limb length, and stable soft tissue coverage with preservation of the original sensation of the sole of the foot at the heel.

Indications: Complex trauma to the foot with devitalized or nonreconstructable forefoot and midfoot, deep bony and soft tissue infection, infected Charcot foot with threatening sepsis, necrosis or gangrene of the forefoot and midfoot with vasculopathy, malignant tumors, certain infections, gigantism of the forefoot.

Contraindications: Possible reconstruction of the midfoot and forefoot beyond the midtarsal (Chopart) joint, loss or irreversible destruction of the sole of the foot or the distal tibial metaphysis.

Surgical technique: The skin incision is designed to retain a long plantar flap with a maximum amount of weight-bearing sole 5-7 cm below amputation level and a shorter anterior flap 1-2 cm below amputation level. Exarticulation or bone resection is performed from anterior to posterior, while preserving the posteromedial vessels to supply the heel flap. The Chopart stump is held in a neutral position avoiding equinus with a tibiotalar external fixator and additional tendon balancing with a noninfected posterior tibialis and one of the peronaeal tendons from medial and lateral through the talar head and Achilles tendon lengthening. Alternatively, a Pirogoff stump with minimal limb length loss (about 2 cm) is achieved with minimal resection at the anterior calcaneal process. The calcaneus is rotated 70-80° and fused to the distal end of the tibia with lag screws or an external frame. Alternatively, a Syme stump is covered with the heel skin after resection of the malleoli flush to the tibial plafond. If anterior wound closure cannot be obtained without tension, temporary vacuum-assisted closure and later definitive coverage with skin grafts, local or free flaps is obtained. In cases of deep infection, the amputation is performed as a staged procedure.

Postoperative management: Nonweight bearing until stable scar formation, early mobilization in a total contact cast. Interim prosthesis after 2-4 weeks, fitting of the definitive prosthesis with special shoewear after 2-3 months.

Results: Over a 12-year period, 15 Chopart, 7 Pirogoff, and 2 Syme amputations were performed. A total of 15 patients had sustained a complex foot trauma, 9 had a deep infection, among them 7 in a diabetic Charcot foot. In 16 patients, among them all with deep infection, 1-4 planned revisions were performed. In 5 patients (20.8%), the stumps were revised subacutely to a more proximal amputation level. In 2 patients with Chopart amputation, a hindfoot fusion was performed to correct equinus, while 1 Chopart and 1 Pirogoff stump were subjected to resection of a prominent exostosis. Except for 2 patients with Charcot foot, all patients with hindfoot amputation could walk barefoot over short distances.