Do all Isler's type sacral fractures necessarily require surgical fixation?

Introduction: A unilateral vertical sacral fracture that exits medial or through the L5-S1 facet joint is considered to affect the lumbo-sacral integrity, and it is denoted as an indication for surgical fixation. However, no studies have analysed the outcomes after non-operative treatment of such injuries.

Methods: A retrospective review of all sacral fractures treated over a five-year period was performed to identify patients with Isler's fractures. Demographic and surgical data, all pre-operative and follow-up images (AP radiographs, CT images), functional outcomes based on VAS, SF-12 and return to work were documented for all patients.

Results: The incidence of Isler's fractures was 18% (34/181). The mean age was 42.12 ± 16.3 years. As per Isler's subtypes, fractures passed through L5-S1 joint in 13 (Type 2a) and medial to it in 15 (Type 2b), fractures of L5 or S1 facets in 3 (Type 1), Type 3 injuries were not detected. All patients had concomitant pelvic ring injuries. Sixteen fractures (neurologically intact, < 1 cm displacement, anterior ring stable, no facetal dislocation) were treated non-operatively while 18 patients underwent surgery. At a mean of 15.2 months, the fractures had united in all patients radiographically. The mean VAS score for low back pain (1.4 ± 1.01 vs 1.5 ± 0.79), ability to squat and sit cross-legged (56.3% vs 55.6%) and return to work (68.8% vs 66.7%), and Majeed score (77.2 ± 3.9 vs 79.6 ± 4.1) were similar in non-surgical and surgical groups, respectively, at the final follow-up.

Conclusion: Our study indicates that 47% of Isler's fractures were mechanically stable and could be effectively treated non-operatively with good radiological and functional outcomes.