Can Unilateral Kyphoplasty Replace Bilateral Kyphoplasty in Treatment of Osteoporotic Vertebral Compression Fractures? A Systematic Review and Meta-analysis.

BACKGROUND Kyphoplasty has been proven to be an efficient method to relieve patient suffering from osteoporotic vertebral compression fractures (OVCFs). Because of its technological superiority, unilateral kyphoplasty consumes less operative time and bone cement than traditional bilateral kyphoplasty. However, there is controversy about which method is most efficient in the treatment of OVCFs. Thus, an overall analysis should be performed to shed light on the facts corroborating both procedures. OBJECTIVE To evaluate the safety and efficacy of unipedicular kyphoplasty versus bipedicular kyphoplasty in treating OVCFs. STUDY DESIGN Inclusion criteria were randomized controlled trials focusing on comparing unilateral versus bilateral balloon kyphoplasty in treatment of OVCFs. The exclusion criteria contained infection, neoplastic etiology, traumatic fracture, neural compression, neurological deficit, spinal stenosis, previous surgery at the involved vertebral body, long-term use of steroids, and kyphoplasty with other invasive or semi-invasive intervention treatment. Retrospective studies, reviews, technology introductions, and biochemical trials were also excluded. SETTINGS The PubMed MEDLINE, Cochrane Library, Web of Science, and EMBASE were systematic searched. Only randomized controlled trials published up to June 2015 comparing unilateral kyphoplasty with bilateral kyphoplasty in treatment of OVCFs were identified. METHODS Two researchers independently screeded the works for inclusion and data extraction. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used to assess the methodological quality and evidence synthesis. RESULTS Six articles with 563 patients were enrolled in this study. Results showed that the unilateral approach required less surgical time (MD, -23.19; 95% CI, [-27.08, -19.31]; P < 0.00001) and cement consumption (MD, -2.07; 95% CI, [-2.23, -1.91]; P < 0.00001), as well as a reduced cement leakage ratio (RR, 0.59; 95% CI, [0.35, 0.99]; P < 0.05) and improved short-term general health (MD, 1.48; 95% CI, [0.02, 2.93], P < 0.05). No significant difference was found in the visual analog scale score (short-term and long-term), Oswestry Disability Index score (mid-term and long-term) kyphotic angle reduction, restoration rate of anterior vertebral height, vertebral height loss rate, postoperative adjacent-level fractures, or in other assessments of 36-Item Short Form Health Survey parameters (short-term and long-term). LIMITATIONS Only 6 studies were included, so that the sample size was still relatively small and publication bias could not be revealed in this study. Observation time of some data was inconsistent. All of these problems could influence the reliability of the results. CONCLUSION Both unilateral kyphoplasty and bilateral kyphoplasty are safe and effective treatments for OVCFs. However, when operative time, cement volume, cement leakage, short-term general health, radiation dose, and hospitalization costs are taken into consideration, unilateral kyphoplasty may be the better choice. Yet, more high-quality RCTs with long-term follow-up are still required to make the final conclusion.Key words: Kyphoplasty, unilateral approach, bilateral approach, osteoporotic vertebral compression fractures, meta-analysis.