Endoscopic distal soft-tissue release in the treatment of hallux valgus: a cadaveric study

Purpose: To study the efficacy and safety of the lateral release of the endoscopic distal soft-tissue procedure in the treatment of hallux valgus.

Methods: Twenty fresh-frozen foot and ankle specimens were used. Ligament-sacrificing release was performed in 10 specimens (group 1). Ligament-sparing release was performed in another 10 specimens (group 2). The relation between the metal rod that passed through the toe web and plantar portal wounds and neural structures, degree of completeness of release of the intermetatarsal ligament, adductor hallucis insertion, and lateral capsular structures was studied.

Results: The common digital nerve of the first intermetatarsal space ran along the medial side of the rod, the medial digital nerve of the second toe ran obliquely and plantar to the rod just proximal to the proximal edge of the intermetatarsal ligament, and the lateral digital nerve of the hallux ran along the plantar lateral border of the metatarsal head and fibular sesamoid in all specimens. The intermetatarsal ligament, adductor hallucis insertion, and lateral capsular ligamentous structures were released completely in all specimens in group 1. The intermetatarsal ligament was preserved and the lateral capsular ligamentous structures were completely released in all specimens in group 2. The adductor hallucis insertion was completely released in 7 specimens. No nerve injury or cartilage damage was noted in all 20 specimens.

Conclusions: With the release of the intermetatarsal ligament, all lateral capsular ligamentous structures including the adductor were released, but with intermetatarsal ligament preservation, only 70% of the specimens had complete adductor release. There was no neural or articular cartilage damage in either group.

Clinical relevance: The study provides an anatomic basis for safe practice of endoscopic distal soft-tissue release in the correction of hallux valgus deformity.