OBJECTIVE

To explore the correlative factors affecting the complications resulting from cement leakage after percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral body compression fractures (OVCF).

METHODS

From February 2005 to October 2008, 71 patients with OVCF were treated by PKP and were retrospectively analyzed. There were 16 males and 55 females, and the average age was 71.5 years (range, 52-91 years). The average duration of disease was 5.7 months (range, 1-11 months). A total of 171 vertebra were involved in fracture including 19 cases of single vertebral fractures, 21 cases of double vertebral fractures, 20 cases of three vertebral fractures, and 11 cases of more than three vertebral fractures. All the treated vertebra were divided into acute (86 vertebra) or subacute (85 vertebra) state based on changes in MRI signal intensity. There was no radiculopathy or myelopathy. The average injected cement volume was 4.6 mL (range, 1.5-6.5 mL). The treatment efficacy was assessed by observing the change in anterior and middle vertebral column height, Cobb angle, visual analogue scale (VAS) and Oswestry functional score at preoperation, 3 days after operation and last follow-up. The patients were divided into cement leakage group and no cement leakage group. All the complications were recorded, and then the correlative factors affecting the complications were analyzed.

RESULTS

All the cases had rapid and significant improvement in back pain following PKP. All patients were followed up for 14 months (range, 7-18 months). There was no cement extravasation resulting in radiculopathy or myelopathy. Four patients (5.63%) had lung-related complications. During the follow-up, 9 recurrence vertebral fractures were observed in 6 patients (8.45%). The anterior and middle vertebral column height, Cobb angle, VAS and Oswestry score were significantly improved when compared with preoperation (P < 0.05). Cement leakage occurred in 17 (9.94%) vertebral bodies; of 17 cases, the cement leaked into the paravertebral space in 7 cases, intervertebral space in 6 cases, channel of needling insertion in 3 cases, and spinal canal in 1 case. Univariate analysis showed statistically significant differences (P < 0.05) in preoperative anterior and middle vertebral column height, injected cement volume and vertebral body wall incompetence between the cement leakage group and no cement leakage group. There were no significant differences (P > 0.05) in preoperative Cobb angle, freshness of vertebral fracture, location of operative vertebrae and operative approach between the two groups. Multiple logistic regression analysis showed that the injected cement volume [odds ratio (OR)=3.105, 95% confidence interval (CI) = 1.674-5.759, P < 0.01] and vertebral body wall incompetence (OR = 11.960, 95% CI = 3.512-40.729, P < 0.01) were the predominant variable associated with the complications resulted from cement leakage.

CONCLUSION

The injected cement volume and vertebral body wall incompetence were the factors affecting the complications. The improvement of surgical technique is the capital factor that may reduce the complications in the PKP.