Medial approach to the calcaneus

Introduction

• Most often used for sustentaculum fractures
• Less commonly used for the calcaneus than lateral approaches
• Originally called the "McReynolds approach"

Position of patient

• Supine, with leg externally rotated for access to the medial hindfoot

Landmarks and incision

Landmarks

• Medial malleolus and the heel

Incision

• Originally described as parallel to the sole of the foot, about half-way between the sole of the foot and the medial malleolus, about 8-10 cm long and centered under the medial malleolus
  • Takes the incision transversely across the Tom Dick ANd Harry structures (PTT, FDL, posterior tibial Artery, tibial Nerve, and FHL)
• Depending on the planned type of fixation, many surgeons now make a more oblique or vertical skin incision that more parallels the course of these structures and thus puts them at less risk to injury

Internervous plane

• No true internervous plane; skin mostly innervated by the medial cutaneous nerves of the leg (branches of the saphenous nerve)
• Skin on heel, however, is innervated by the medial calcaneal branch of the tibial nerve
  • In deep dissection, tibial nerve is identified with neurovascular bundle and often needs to be mobilized for access to the bony calcaneal surface for mobilization

Superficial dissection

• After skin incision, identify and protect the medial calcaneal branch of the tibial nerve in the posterior aspect of the wound
• This superficial nerve, if cut, leads to numbness of the medial heel

Deep dissection

• Incise the flexor retinaculum
  • Posterior NV bundle (tibial nerve, tibialis posterior artery) and the  PTT, FDL, and FHL are just below this; dissection should proceed slowly until these are identified
  • They should be protected, and can be elevated superiostally from a posterior to anterior direction, and protected with a Penrose drain
  • Alternatively only the NV bundle can be protected with a Penrose drain if the tendons are left in place
• Abductor hallucis muscle is retracted caudad, allowing direct access to the medial calcaneus and sustentacular fragment

Dangers

• Medial calcaneal branch of the tibial nerve superficially
• Deep, the dangers are to the tibial nerve and tibialis posterior artery, as well as the tendons PTT, FDL and FHL

How to enlarge the approach

• No enlargement necessary as this approach provides full access to the sustentacular fragment.

Figures