The present meta-analysis indicated that the use of computer navigation in patients undergoing THA improves the precision of acetabular cup placement by decreasing the number of outliers, and decreases leg length discrepancy. More high quality RCTs are required to further confirm our results.

III.

BackgroundThe use of drains following posterior spinal surgery is controversial. Thus, the aim of this meta-analysis was to review the advantages and adverse effects of closed suction drainage systems in posterior spinal surgery.MethodsAll randomized and non-randomized controlled trials comparing the use of closed suction drainage with no drainage in posterior spinal surgery were sought in PubMed, Medicine, Embase, and other Internet databases. All of the literature was searched and assessed by two independent reviewers, according to the standards of Cochrane systematic reviews. Data on functional and radiological outcomes in the two groups were pooled, which were then analyzed with RevMan software, version 5.2.ResultsFour randomized controlled trials (RCTs) and four non-RCTs met the inclusion criteria. Meta-analysis revealed that no significant differences were found regarding wound infection (P = 0.83), hematoma (P = 0.48), neurological injury (P = 0.21), estimated blood loss (P = 0.59), or dry and moderate dressing drainage between the groups. The number of patients with saturated dressings was larger in the no drainage group (P = 0.002).ConclusionsThere is no obvious evidence to support the application of closed suction drains for posterior spinal surgery. Because of the limited quality of the evidence currently available, more high-quality RCTs with better experimental designs and larger patient samples should be performed.