Femoral offset restoration affects the outcome of revision in patients with periprosthetic femoral fractures of Vancouver B2 -a single- center retrospective cohort study

Abstract

Abstract Background: Femoral offset (FO) restoration plays an important role in improving the prognosis and life quality of patients undergoing hip replacement. However, it is not given enough attention in revisions of patients with periprosthetic femoral fractures (PPFF) while more attention is paid to reduction, fixation of fracture and stabilizing prosthesis. This study aims to evaluate the effect of FO restoration on the function of hip joint in revisions of patients with PPFF of Vancouver B2. What’s more, we study whether there is a difference in FO restoration between modular and nonmodular stems. Methods: A retrospective review of 20 patients with PPFF of Vancouver B2 revised with a tapered fluted modular titanium stem and 22 patients with PPFF of Vancouver B2 revised with a tapered fluted nonmodular titanium stem from 2016 to 2021 was conducted. According to the difference between FO of affected side and healthy side, 26 patients were divided into Group A(difference≤4mm) and 16 patients were divided into Group B(difference＞4mm). Postoperative Harris Hip Score（HHS）,range of motion of hip joint, length of both lower limbs and dislocation were compared between Group A and Group B. Proportion of patients with FO restoration (difference≤4mm)and stem subsidence were compared between modular and nonmodular groups. Results: The mean follow-up time was 34.3±17.3 months, and all cases achieved fracture healing at the last visit. Patients of Group A had higher HHS, larger range of abduction, fewer dislocations and less limbs length discrepancy (LLD). Patients of modular group had a higher proportion of FO restoration and less subsidence. Conclusion: FO restoration improves the postoperative hip joint function，reduces dislocation and LLD in revisions of patients with PPFF of Vancouver B2. Compared with nonmodular prosthesis, modular prosthesis tends to be easier for FO restoration under complex circumstances.