Introduction

Heterotopic ossification (HO) is the formation of pathological bone in muscle or soft tissue (ref). The incidence in individuals following a spinal cord injury (SCI) has been reported to vary greatly, ranging from 10% to 78% (Banovac 2001; van Kuijk et al. 2002; Ranganathan et al. 2015). HO occurs most frequently in the first two months after SCI, below the level of paralysis (Banovac et al. 2001), and most commonly forms in the hip but rarely in the peripheral joints such as the elbows and knees (Ranganathan et al. 2015).