Comparison of radiological and clinical results of balloon kyphoplasty according to anterior height loss in the osteoporotic vertebral fracture.

BACKGROUND CONTEXT: Percutaneous kyphoplasty is effective for pain reduction and vertebral height restoration in patients with osteoporotic vertebral fractures. However, in cases of severely collapsed fractures involving the loss of more than 70% of the vertebral height, kyphoplasty is technically difficult to perform and the outcomes remain unknown.

PURPOSE: To compare the vertebral height restoration rate, kyphotic angle, and clinical results of patients who underwent kyphoplasty according to the degree of anterior vertebral height loss. In addition, to determine the feasibility and effects of kyphoplasty on severely collapsed osteoporotic vertebral fractures.

STUDY DESIGN/SETTING: A retrospective study.

PATIENT SAMPLE: A total of 129 patients (145 vertebrae) who underwent kyphoplasty for osteoporotic painful vertebral fracture and followed up for more than 1 year between September 2005 and August 2012 were recruited for the analysis.

OUTCOME MEASURES: The patients' kyphotic angle, anterior vertebral height, and anterior vertebral height restoration ratio 1 year after surgery were compared. Pre- and postoperative pain around the fractured vertebra and the radiological and clinical results according to bone mineral density (BMD) were also compared.

METHODS: Patients were divided into three groups for comparison, according to radiographic findings. Patients with an anterior height compression ratio more than 70% at the time of fracture comprised Group I, patients with a compression ratio of 50-70% comprised Group II, and those with a compression ratio of 30-50% comprised Group III.

RESULTS: Group I showed a greater extent of anterior height restoration immediately after surgery compared with the other groups, which noticeably decreased over time. All three groups showed significant restoration of the anterior vertebral height between pre- and postoperative values. The anterior vertebral height 1 year after surgery did not differ between Group I and Group II but was significantly higher in Group III. There was no correlation between the BMD and restoration or decrease of anterior vertebral height over time. Pain around the fractured vertebra significantly decreased in all groups immediately and 1 year after surgery compared with preoperative levels, although the pain level 1 year after surgery did not differ significantly between the groups.

CONCLUSIONS: In patients with an anterior vertebral compression ratio more than 70% because of osteoporotic vertebral fracture, although the anterior height and kyphotic angle were significantly lower than those of patients with an anterior vertebral compression ratio of 30% to 50%, kyphoplasty significantly improved the degree of pain, restored the anterior vertebral height, and maintained the kyphotic angle. Therefore, kyphoplasty can be a useful approach in patients with an anterior vertebral compression ratio more than 70%.