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Updated: Apr 6, 2026
An Anatomical Study of Nerves at Risk During Minimally Invasive Hallux Valgus Surgery
Published on: February 17, 2018
Safe Zone for Neural Structures in Medial Displacement Calcaneal Osteotomy: A Cadaveric and Radiographic
Paul G Talusan1, Ezequiel Cata2, Eric W Tan3
1Department of Orthopaedic Surgery, MedStar Union Memorial Hospital, Baltimore, MD, USA Department of Orthopaedic Surgery, University of Michigan School of Medicine, Ann Arbor, Michigan, USA.
Background:
We aimed to define reference lines on standard lateral ankle radiographs that could be used intraoperatively to minimize iatrogenic nerve injury risk in medial displacement calcaneal osteotomy.
Methods:
Forty cadaveric specimens were used. In 20 specimens, the sural, medial plantar (MP), and lateral plantar (LP) nerves were sutured to radiopaque wire, and a lateral ankle radiograph was obtained. On the radiograph, a line was drawn from the posterior superior apex of the calcaneal tuberosity to the origin of the plantar fascia and labeled as the "landmark line." A parallel line was drawn 2 mm posterior to the most posterior nerve, and the area between these lines was defined as the safe zone. In 20 additional specimens, an osteotomy was performed 1 cm anterior to the landmark line using a percutaneous or open technique. Dissection was performed to assess for laceration of the sural, MP, LP, medial calcaneal (MC), or lateral calcaneal (LC) nerves.
Results:
The safe zone was determined to be within the area 11.2 ± 2.7 mm anterior to the landmark line. After open osteotomy, lacerations were found in 3 of 10 MC nerves and 3 of 10 LC nerves. After percutaneous osteotomy, lacerations were found in 2 of 10 MC nerves and 1 of 10 LC nerves. No lacerations of the sural, MP, or LP nerves were found with either osteotomy.
Conclusions:
The safe zone extended 11.2 ± 2.7 mm anterior to the described landmark line. The MC and LC nerves were always at risk during medial displacement calcaneal osteotomy.
Clinical Relevance:
Nerve injury to both major and minor sensory nerves is likely underrecognized as a source of morbidity after calcaneal osteotomy. The current study provides a ready intraoperative guideline for minimizing this risk.
