Purpose: To compare the short- and long-term clinical outcomes, operation times, restoration rate, dosage of polymethylmeth-acrylate (PMMA) injected, complications and X-rays exposure frequency between unilateral and bilateral kyphoplasty approaches for the treatment of OVCF.
Study design: Systematic review and meta-analysis.
Methods: Randomized or non-randomized controlled trials published up to April 2015 that compared the unilateral and bilateral PKP for the treatment of OVCF were acquired by a comprehensive search in the Cochrane Controlled Trial Register, PubMed, MEDLINE, EMBASE, Web of Science, OVID. Exclusion criteria were patients with neoplastic etiology (metastasis or myeloma), infection, neural compression syndrome, invasive and degenerative disease, traumatic fracture, re-operation, neurological deficits, significant scoliosis and spinal stenosis. The main end points included: operation times, the short- and long-term postoperative Visual Analogue Scale (VAS) scores, the short-term postoperative Oswestry Disability Index (ODI), restoration rate, dosage of PMMA injected, cement leakage, X-ray exposure frequency and postoperative adjacent-level fractures.
Results: A total of 8 studies involving 428 patients were included in the meta-analysis. The mean operative time was shorter in the unilateral groups compared with the bilateral groups [P < 0.05, weighted mean difference (WMD) -19.74 (-30.56, -8.92)]. There was no significant difference in the short-term postoperative VAS scores [P > 0.05, WMD 0.03 (-0.34, 0.40)], the long-term postoperative VAS scores between them [P > 0.05, WMD 0.01 (-0.42, 0.45)] and the short-term postoperative ODI [P > 0.05, WMD -0.33 (-2.36, 1.69)] between the two groups. The unilateral approaches required significantly less dosage of PMMA than the bipedicular approaches did [P < 0.05, WMD -1.56 (-1.59, -1.16)]. The restoration rate in the bilateral groups was higher than the unilateral groups [P < 0.05, WMD -7.82 (-12.23, -3.41)]. There was no significant difference in the risk ratio of cement leakage [P > 0.05, RR 0.86 (0.36, 2.06)] and postoperative adjacent-level fractures [P > 0.05, RR 0.91 (0.25, 3.26)] between the two methods. The mean X-ray exposure frequency in the unilateral groups was greater than the bilateral groups [P < 0.05, WMD -5.69 (-10.67, -0.70)].
Conclusions: A definitive verdict could not be reached regarding which approach is better for the treatment of OVCF. Although unilateral PKP was associated with shorter operative time, less X- ray exposure frequency and dosage of PMMA than bilateral PKP. There was no apparent difference in the short- and long-term clinical outcomes and complications between them. However, bilateral PKP approaches were higher than unilateral PKP in term of the restoration rate. But on account of lack of some high-quality evidence, we hold that amounts of high-quality randomized controlled trials should be required and more complications should be analysed to resolve which surgical approach is better for the treatment of OVCF in the future.
Keywords: Bilateral kyphoplasty; Meta-analysis; OVCF; Treatment; Unilateral kyphoplasty.