Abstract: Objective: To evaluate the efficacy and safety of proximal femoral nail antirotation (PFNA) and dynamic hip screw (DHS) for unstable intertrochanteric fractures using meta-analysis. Methods: The PubMed, Embase, Cocharane Central Register of Controlled Trials, Google Scholar, China Science and Technology Papers and Citation Database (CSTPCD) and China Journal Full-text Database (CNKI) were searched for published randomized controlled trials before January 1, 2019. Two researchers independently screened the literature in the light of the inclusion and exclusion criteria, evaluated the quality of the studies and extracted the data which were consisted of clinical efficacy indexes, such as incision length, operation time,intraoperative blood loss, weight-bearing time,fracture-healing time, Harris hip score and safety indicators like complications. Meta-analysis was performed with the Revman 5.3 software provided by Cochrane Community in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standard. Results: Nine randomized controlled trials met the requirement with a total of 779 patients, of whom 383 were fixed with PFNA and 396 with DHS. Meta-analysis demonstrated that PFNA was associated with smaller surgical incision length [MD=-7.43, 95%CI (-9.31, -5.55), P<0.05], shorter operation time [MD=-22.76, 95%CI (-29.57, -11.95), P<0.05], less intraoperative blood loss [MD=-216.34, 95%CI (-275.18, -157.49), P<0.05], earlier weight bearing after surgery [MD=-12.34, 95%CI (-17.71, -6.97), P<0.05], shorter fracture healing time [MD=-5.00, 95%CI (-7.73, -2.26), P<0.05], higher postoperative Harris hip score [MD=12.22, 95%CI (3.88, 20.55), P<0.05], higher rate of excellent Harris hip score [OR=3.56, 95%CI (1.44, 8.81), P<0.05] and lower incidence rate of postoperative complications [OR=0.48, 95%CI (0.33, 0.70), P<0.05], such as hip varus, wound infection, urinary tract infection, pulmonary infection, pressure sore, deep vein thrombosis, pulmonary embolism, heart failure and cerebral infraction when compared with DHS. No statistical difference was shown between the groups when it came to subgroup analysis by age. However, there was no significant difference (P>0.05) in the duration of hospitalization and the complications resulting in the occurrences of internal fixation loosening, such as femoral shaft fracture (during or post operation), internal fixation fracture, cut-out, displacement or retraction. Conclusion: Current published evidence supports the superiority of PFNA to DHS for unstable intertrochanteric fractures in terms of clinical efficacy. The conclusion was limited because of the relatively low quality of evidence with low strength of confidence. Large scale and high-quality randomized controlled trials are required to validate the safety of PFNA and DHS for unstable intertrochanteric fractures.

Key words: Hip fractures, Bone nails, Bone screws, Fracture fixation, intramedullary, Meta-analysis