IN SITU ARTHRODESIS FOR THE SEQUELAE OF OS CALCIS FRACTURE

Abstract

Introduction: Distraction bone block arthrodesis has been advocated in the literature to treat the late sequelae of os calcis fracture with loss of heel height including the prevention of anterior impingement. We have studied a consecutive series of subjects who have had in situ arthrodesis for subtalar arthrosis as a consequence of os calcis fracture with marked loss of talocalcaneal height paying particular attention to range of movement and anterior impingement.

Materials and Methods: Between 1997 and 2003 31 consecutive subjects underwent subtalar arthrodesis. Five subjects who had undergone ORIF, two non-unions and three subjects with bilateral injuries were excluded. Two subjects who had marked coronal displacement that required additional surgery at the time of arthrodesis were also excluded. Two subjects were lost to follow up leaving 17 for assessment. AOFAS hind foot scores improved from 29.8 (range 13–48) preoperatively to 77.8 (range 48–94) postoperatively. Mean loss of talocalcaneal height was 10.3mm and the mean talar declination angle was 6.7 degrees which was 35% of the normal side. One subject suffered anterior ankle pain but none had anterior impingement. Two subjects complained of difficulty ascending slopes and stairs and four of difficulty descending. Mean ankle dorsiflexion was 11.6 degrees (range 0–24) compared to 14.7 degrees on the normal side: A reduction of 21.1%. Mean plantarflexion was 35.5 degrees (range 24–60) compared to 44.6 degrees on the normal side: A reduction of 20.4%.

Discussion: Our results suggest that anterior impingement is not a significant problem in os calcis fracture, even when loss of talocalcaneal height is marked. We recommend ISA combined with lateral wall ostectomy for all cases of subtalar arthrosis as a result of os calcis fracture, without marked coronal deformity, regardless of the degree of talocalcaneal height loss.