Fasciotomy of the foot: an anatomical study with special reference to release of the calcaneal compartment.

Three patients with calcaneal fractures developed clawing of the lesser toes as a late sequela. Believing that this complication may be the result of contractures from an occult compartment syndrome of the foot, an investigation of the anatomical compartments of the foot was performed. The various compartments of 17 unembalmed adult lower limb specimens were injected with dyed gelatin in a controlled fashion. After freezing, the feet were sectioned either transversely or sagittally. The distribution of the dyed gelatin was then studied. Nine compartments were identified. These were the (1) medial, (2) superficial, (3) lateral, (4) adductor, (5-8) four interossei, and (9) calcaneal. The contents of each compartment was then studied as was the compartment's location in the foot and its position relative to other compartments. We identified a new, separate compartment which lies deep to the superficial compartment in the hindfoot area only. This compartment contains the quadratus plantae muscle. We have named it the "calcaneal" compartment to emphasize its hindfoot location. In addition, a communication was demonstrated between the calcaneal compartment and the deep posterior compartment of the leg through the retinaculum behind the medial malleolus, following the neurovascular and tendinous structures. Claw toe deformity following calcaneus fracture appears to be due to late contracture of the quadratus plantae muscle in the calcaneal compartment. A surgical technique for release of all of the foot compartments is described.