Cannulated screws vs. dynamic hip screw vs. hemiarthroplasty vs. total hip arthroplasty in patients with displaced and non-displaced femoral neck fractures: a systematic review and frequentist network meta-analysis of 5,703 patients

Abstract Background: To identify the best operative procedure in human participants with a displaced or non-displaced femoral neck fracture comparing cannulated screw (CS) fixation, dynamic hip screw (DHS) fixation, hemiarthroplasty (HA), and total hip arthroplasty (THA) in terms of surgical and functional outcomes, reoperation and postoperative complications. Methods: We searched the following databases for randomized controlled trials (RCTs) or quasi RCTs until July 31st, 2022: PubMed, The Cochrane Library, Clinical trials, CINAHL, and Embase. A pairwise and network meta-analysis was performed to simultaneously assess the comparative effects of the four operative procedures, using fixed-effects and random-effects models estimated with frequentist approach and consistency assumption. Mean differences (MDs) with 95% confidence intervals (CIs) were estimated for continuous variables and odds ratios (ORs) with 95% CIs were estimated for binary variables. Results: A total of 33 RCTs, involving 5,703 patients (92% with a displaced and 8% with a non-displaced femoral neck fracture), were included in our network meta-analysis. Of them, 913 (16%) patients were operated with CS fixation, 372 (6.5%) with DHS fixation, 2,606 (46%) with HA in, and 1,812 (31.5%) with THA. CS fixation was best in operation time (CS: MD=-57.70, 95% CI -72.78;-42.62; DHS: MD=-53.56, 95% CI -76.17;-30.95; HA: MD=-20.90, 95% CI -30.65;-11.15; THA: MD=1.00 Reference) and intraoperative blood loss (CS: MD=-3.67, 95% CI -4.44;-2.90; DHS: MD=-3.20, 95% CI -4.97;-1.43; HA: MD=-1.20, 95% CI -1.73;-0.67; THA: MD=1.00 Reference). In life quality and functional outcome, measured at different time points with EQ-5D and the Harris Hip Score (HHS), THA ranked first and HA second (e.g. EQ-5D 2 years postoperatively: CS: MD=-0.20, 95% CI -0.29; -0.11; HA: MD=-0.09, 95% CI -0.17; -0.02; THA: MD=1.00 Reference; HHS 2 years postoperatively: CS: MD=-5.50, 95% CI -9.98; -1.03; DHS: MD=-8.93, 95% CI -15.08; -2.78; HA: MD=-3.65, 95% CI -6.74; -0.57; THA: MD=1.00 Reference). CS fixation had the highest reoperation risk, followed by DHS fixation, HA, and THA (CS: OR=9.98, 95% CI 4.60; 21.63; DHS: OR=5.07, 95% CI 2.15; 11.96; HA: OR=1.60, 95% CI 0.89; 2.89; THA: OR=1.00 Reference). Distinguishing between displaced and non-displaced fractures showed no relevant differences in our network meta-analysis. Conclusion: In our patient cohort with displaced and non-displaced femoral neck fractures, HHS, EQ-5D, and reoperation risk showed an advantage of THA and HA compared to CS and DHS fixation. Based on these findings, we recommend giving preference to hip arthroplasty, and considering internal fixation of femoral neck fractures only in individual cases.