Subsequent vertebral fractures following spinal fusion surgery for degenerative lumbar disease: a mean ten-year follow-up.

摘要

STUDY DESIGN: Case-control study. OBJECTIVE: To assess the long-term prevalence of vertebral fractures after lumbar spinal fusion with instrumentation. SUMMARY OF BACKGROUND DATA: The incidence of the adjacent and the nonadjacent, remote level subsequent vertebral fractures after lumbar spinal fusion is not well described in the literature. METHODS: The study is a retrospective analysis of 100 consecutive patients of 55 years of age or older with spinal fusion for degenerative diseases between L1 and S1, and instrumentation for less than 4 segments. Patients with prevalent vertebral fractures defined at the time of surgery, or patients with secondary causes of osteoporosis were excluded. Mean follow-up period was 10.2 years (range, 7-14 years). Acute vertebral fractures were determined by magnetic resonance imaging and lateral spine radiographs. RESULTS: Acute vertebral fractures were determined in 20 vertebrae in 14 (24%) of the 59 female patients, whereas 1 male patient (2%) had 1 vertebral fracture during the follow-up period. Eighteen of the 21 fractures occurred within 2 years of the spinal instrumentation surgery. Regarding time to fracture occurrence after surgery, adjacent level fractures occurred within 8 months, and remote level fractures occurred between 8 and 22 months after surgery. CONCLUSION: Postmenopausal female patients who underwent lumbar spinal instrumentation surgery were susceptible to develop subsequent vertebral fractures within 2 years after surgery. The greater the number of spinal segments between the fracture and the instrumentation was, the longer the time after surgery.