Risk factors for rod fracture in patients with severe kyphoscoliosis following posterior vertebral column resection / 中华骨科杂志

ABSTRACT

Objective To investigate the risk factors and revision strategies for rod fracture in patients with severe kyphoscoliosis following posterior vertebral column resection (PVCR).Methods Between June 2003 and June 2011,7 patients (4 males and 3 females) who developed rod fractures following PVCR in our institution were retrospectively reviewed.The average age was 24.4 years (range,12-39 years) at the time of primary surgeries.The occurrence times and locations of the rod fractures were recorded and the risk factors for the fractures were analyzed.Results The occurrence times of the rod fractures ranged from 6 to 53 months.Five cases of fracture occurred within 2 years after the primary surgeries,while the other 2 cases occurred more than 4 years after the primary surgeries.Six cases of fracture occurred at levels of osteotomies and 1 case occurred at 1 level below the osteotomy.The potential reasons for rod fractures were listed as follows(1)residual kyphosis (1 case); (2) residual kyphosis combined with unsteady gait (1 case); (3) residual kyphosis combined with single rod fixation (1 case); (4) residual kyphosis combined with malposition of titanium mesh cage (1 case); (5) residual kyphosis combined with anterior column defect; (6) injury (2 cases).Six patients underwent revision surgeries,5 patients received one-stage combined anterior-posterior approach surgeries,while 1 patient received single posterior surgery.They were followed up for 12 to 22 months (average,18months).At final follow-up,all patients obtained satisfying corrections and graft fusion,without internal fixationrelated complications.Conclusion Rod fractures mostly occur at levels of osteotomies within 2 years after PVCR.Residual kyphosis is the main risk factor for the rod fracture.Injury,anterior column defects,unsteady gait,single rod fixation and malposition of titanium mesh cage also increase risks of rod fractures.