Outcomes after Dynamic Hip Screw or 3 Cannulated Hip Screws for the Fixation of Displaced and Undisplaced Intracapsular Neck of Femur Fractures. A Comparative Study with mean 18 month follow-up

Abstract: Background: Intracapsular hip fractures may be managed by fixation or arthroplasty depending on patient age and fracture configuration. The implant of choice for fixation remains controversial and can depend on surgeon preference and experience. The aim of this study is to compare outcomes of two fixation methods - the Dynamic hip screw (DHS) and 3 parallel cannulated hip screws (CHS)- in treating intracapsular hip fractures. Methods: We performed a retrospective analysis on intracapsular hip fractures treated surgically with either three cannulated hip screws (CHS) or 2-hole dynamic hip screw (DHS) between January 2013 and June 2019. A total of 230 patients were included. The mean follow up was 18 months. We compared these groups with respect to fracture displacement, radiological signs of union, AVN, metalwork failure, re- operation and infection rates. Results: The study demonstrated no statistically significant difference in age, gender distribution, ASA score or fracture patterns between the groups. The rate of AVN in the CHS group was higher (13.5% vs 9.5% p= 0.39), while metal irritation was significantly higher in the CHS group (14.7% vs 2.7%, p= 0.006). We found higher reoperation rates in the group undergoing CHS (22.4% vs 18.9%, p= 0.49). Fracture configuration appears to demonstrate a much more significant effect on outcome, with a significantly higher incidence of reoperation (p<0001), AVN (p=0.009), non-union (p<0.0001) and metal cut-out (p=0.0012) in patients with displaced fractures irrespective of the implant used. Conclusions: In the surgical management of intracapsular hip fractures, the use of CHS over DHS or vice versa can simply be a case of surgeon preference. Our study seems to imply a statistically insignificant difference, with the CHS group demonstrating a higher overall risk of requiring revision surgery. Fracture configuration appears to play a larger role than implant choice in the outcome of these patients. Keywords: Hip Fracture Intracapsular Fixation Femur.