Rotational Osteotomy and Subtalar Arthrodesis for Subtalar Arthritis With Calcaneal Malunion: A Technical Note

Abstract

Symptomatic subtalar arthritis that is unresponsive to conservative treatment can be treated using subtalar arthrodesis. 23 However, when the collapsed posterior articular facet is not reduced, causing a significant loss in height of the calcaneus, in situ subtalar arthrodesis alone may not be sufficient. 2 Subtalar distraction arthrodesis is recommended to restore the height of the calcaneus and arch of the foot and reinstitute the functional length of the gastrocnemius-soleus complex. 5 However, for cases with significant proximal migration of the entire calcaneal tuberosity, creating a rocker-bottomshaped calcaneus, subtalar joint distraction has certain limitations in repositioning the tuberosity to restore the height (Figure 1). 13,14,21 In a tongue-type Sanders 2C fracture, 15 in which the posterior articular facet is in continuity with the calcaneal tuberosity, severe depression of the posterior articular facet will rotate and elevate the calcaneal tuberosity proximally, creating a rocker-bottom-shaped calcaneus. When this deformity is not corrected in the initial treatment and results in malunion, it is extremely difficult to reposition the calcaneal tuberosity to the anatomical position using subtalar joint distraction. Furthermore, even if the calcaneus tuberosity could be repositioned downward, the rocker-bottom deformity with plantar exostosis that can cause plantar pain during weightbearing cannot be corrected using subtalar distraction arthrodesis. 20 We developed a technique combined with subtalar arthrodesis to restore the height of the calcaneus and arch of the foot. In addition, the functional length of the gastrocnemius-soleus complex could be reinstituted using dome-shaped osteotomy on the posterior articular facet followed by rotation of the thalamic portion of the calcaneus (the posterior part of the calcaneus that supports the posterior articular facet). 17 To the best of our knowledge, this report is the first to apply dome-shaped osteotomy on the posterior articular facet for the rotational correction of calcaneal malunion with significant height loss.