Is Unilateral Kyphoplasty as Effective and Safe as Bilateral Kyphoplasties for Osteoporotic Vertebral Compression Fractures? A Meta-analysis

An osteoporotic vertebral compression fracture is a common condition in elderly people, especially women. The percutaneous kyphoplasty is an effective treatment for osteoporotic vertebral compression fractures. Controversy remains regarding whether a unilateral or a bilateral approach is superior, and to our knowledge, there have been no large studies comparing these two approaches, therefore a meta-analysis synthesizing the data on this question is warranted. We asked the following questions: (1) Is there evidence to suggest a benefit in clinical outcome as assessed by the VAS and Oswestry Disability Index of a unilateral kyphoplasty or bilateral kyphoplasties? (2) Are the complications associated with the two approaches different? (3) Do the procedures result in different kyphosis angle reduction or anterior vertebral height restoration? (4) Is the surgical time for the procedures different? We searched the Cochrane Library, PubMed MEDLINE, EMBASE, Web of Knowledge MEDLINE (January 1980 to June 2013), and reference lists of eligible prospective studies. The levels of the evidence and recommendations were assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Five studies encompassing 253 patients met the inclusion criteria. The short- and long-term clinical outcomes as assessed by the VAS and Oswestry Disability Index showed no differences between unilateral and bilateral kyphoplasties (p = 0.41, p = 0.60 for VAS; p = 0.10, p = 0.36 for Oswestry Disability Index). There were no differences in complications such as cement leakage and adjacent vertebral fractures associated with the two approaches (p = 0.43 and p = 0.95). The kyphosis angle reduction and anterior vertebral height restoration showed no difference between the two approaches (p = 0.34 and p = 0.46). The unilateral approach was shorter in terms of surgical time (mean difference, -24.98; p < 0.0001). The overall GRADE system evidence quality was very low, with only high evidence for operation time, which lessens our confidence in recommendations. Unilateral and bilateral percutaneous kyphoplasties appear to be safe and effective for treating osteoporotic vertebral compression fractures. No clinically important differences were found between them. Considering less operation time and less cost, we suggest that a unilateral percutaneous kyphoplasty is advantageous, but because of the poor quality of the evidence, high-quality randomized controlled trials are required to resolve this issue.