Risk Factor and Diagnosis of Sacral Insufficient Fracture after Multilevel Fusion: A Case Report and Literature Review

Sacral insufficiency fracture occurs with normal stress on abnormal bone. Sacral fractures after posterior multilevel lumbosacral fusion are uncommon complications. Only a few case series and case reports have been published so far. Here we describe five patients who have sacral fracture after multilevel fusion surgery. We retrospectively reviewed all patients treated at our institution by the author (Pf. K) for sacral fractures following an instrumented spinal arthrodesis with extension to S1 during the period of 2008 to 2015 (Total 158 cases). We describe these five patients’ characteristics, risk factors, symptom after surgery, and treatment plan. There was delay in diagnosis because it was difficult to find it in plain radiography. Computed tomography and MRI can detect most such fractures. Thus, they should probably be performed routinely when patients complain of renewed buttock pain after lumbosacral fusion. There are mainly three optional treatments for sacral fracture: conservative treatment, sacroplasty, and revision operation. Three patients who underwent revision surgery explained that their back pain and leg pain were improved dramatically. Early surgery can be considered because it can help patients relieve pain and ambulation earlier. Even though treatment of choice for sacral fracture is conservative management, surgery should be considered as one of good options for sacral fracture.