Comparison of the accuracy between imageless navigation and manual freehand approaches for total hip arthroplasty: a systematic review and meta-analysis

Abstract Purpose Several researches comparing the imageless navigation (IN) system and manual freehand (MF) approaches for the total hip arthroplasty (THA) have been published, but the curative effect is still contentious. This meta-analysis aims to systematically compare the differences between the two approaches. Methods Random controlled trials which compared the clinical efficacy between IN and MF approaches for THA were retrieved between June 1999 and June 2019, from PubMed, Embase, Cochrane Library, etc. Mean difference, odds ratio and corresponding 95% confidence intervals (CI) were used for estimating the effects of the two methods. I2 test and Chi-square test were used to test heterogeneity among studies. Statistical analyses were done using Review Manager Version 5.3. Results Eleven pieces of literature were presented. No statistical variation in IN and MF approaches on Harris hip score (HHS) (95% CI: -2.91, 1.47; p = 0.52), cup inclination (95% CI: -0.60, 1.95; p = 0.30), cup anteversion (95% CI: -2.85, 0.91; p = 0.31), cup abduction (95% CI: -3.65, 0.63; p = 0.17), length of incision (95% CI: -0.25, 0.29; p = 0.90), blood loss (95% CI: -69.14, 25.61; p = 0.37) and the decrease of hemoglobin (Hb) at 24 h after surgery (95% CI: -0.45, 0.40; p = 0.91), etc. However, the number of cases outside the safe zone in the IN group were less than in the MF group (95% CI: 0.08, 0.25; p Conclusions IN system is more accurate than MF approaches in THA, but IN system needs more operation time. There is no difference between the approaches on HHS, cup inclination, cup anteversion, length of incision, blood loss and the decrease of Hb at 24 h after surgery.