Review Question - QID 211825

Patients who undergo Chopart amputations often develop postoperative equinus. This is prevented by transferring the tibialis anterior to the talus and performing an Achilles tendon lengthening. The tibialis anterior is innervated by the deep peroneal nerve.

The Chopart amputation is a partial foot amputation through the talonavicular and calcaneocuboid joints. This amputation may result in a significant equinovarus deformity with weight-bearing through the scar line, predisposing to skin breakdown over time. Thus, lengthening the Achilles tendon and transferring the tibialis anterior to the talar neck should be performed in conjunction with this amputation. This transfer results in ankle dorsiflexion and distributes the weight-bearing portion more centrally. An Achilles tendon lengthening is performed at the same time to accommodate this posteriorly.

Krause et al. investigated ankle dorsiflexion arthrodesis to salvage Chopart amputation with anterior skin insufficiency. They reported that the addition of an ankle arthrodesis, either at the time of amputation or in a delayed fashion, was successful in most patients at this amputation level. They highlighted that this intervention enabled the patients to preserve the advantages of a full-length limb with terminal weight-bearing.

Early et al. reviewed transmetatarsal and midfoot amputations. They reported that historically, amputations through the Lisfranc and Chopart's joint lines resulted in significant complication rates, however, with improvements in patient selection and surgical technique (i.e. Achilles tendon lengthening and tendon transfers), these two amputation levels are viable options to consider when attempting salvage of the hindfoot structures.

Figure A depicts a Chopart amputation, through the talonavicular and calcaneocuboid joints.

Incorrect Answers:
Answer 1-4: Innervation of the tibialis anterior is provided by the deep peroneal nerve.