Relationship of the Scarf valgus-inducing osteotomy of the calcaneus to the medial neurovascular structures.

Abstract

The Scarf valgus inducing osteotomy of the calcaneus is an operative technique to correct varus deformity of the hindfoot. It is versatile with significant corrective power; however, the neurovascular structures are in close proximity on the medial side and thus may be harmed during the osteotomy. Moreover, because this type of osteotomy can cause a great lateral translation, traction of the medial neurovascular structures is possible. We performed an anatomic study to evaluate the medial soft tissues after a lateralizing Scarf-type calcaneal osteotomy. The osteotomies were carried out on ten fresh-frozen cadaver specimens. We performed the osteotomy and induced valgus. Then we performed a medial dissection to identify the important medial structures: the medial and lateral plantar nerve (MPN , LPN) and the posterior tibial artery (PTA). We noted their relation to the osteotomy and their integrity. In several cases, one or more of the structures were sectioned. In five cases, all the structures crossed the osteotomy, four of which even a transection of one or both of the plantar nerves occurred. Although the PTA crossed the osteotomy in eight specimens, there was no transection of this structure. Scarf osteotomy of the calcaneus is a highly corrective osteotomy. However, caution must be exercised when performing as the medial neurovascular structures cross the osteotomy lines and transection can occur. When performing the osteotomy one should keep in mind that vigorous sawing and large displacement can cause damage to the medial neurovascular structures.