Dual Mobility Acetabular Cup Versus Hemiarthroplasty in Treatment of Displaced Femoral Neck Fractures in Elderly Patients: Comparative Study and Results at Minimum 3-Year Follow-up

BACKGROUND: Hip fractures are serious injuries associated with relatively high mortality rates and disabilities, commonly seen in elderly persons. There is an ongoing debate regarding the advantages of various hip arthroplasty devices. This study aimed to analyze the long-term advantages of 2 different surgical procedures and assess if the dislocation rate, Harris Hip Score (HHS), and functional independence measure (FIM) are more favorable in dual mobility (DM) than those in hemiarthroplasty (HA). HYPOTHESIS: Dual mobility procedures provide better postoperative outcomes than HA in terms of HHS, FIM, and dislocation rate. MATERIALS AND METHODS: The survey was a prospective, comparative interventional single-blinded study performed at the University Clinical Center of Kosovo, a tertiary health-care institution. A total of 94 patients underwent DM or conventional bipolar HA for repair of displaced femoral neck fractures within 2 weeks of injury. Primary outcomes were postoperative dislocation rate, FIM, and HHS. Secondary outcomes included duration of surgery, estimated intraoperative blood loss, time to first postoperative full weight-bearing, time to walking ability with and without crutches, mortality rate, and postoperative infection rate. RESULTS: There were no significant differences for most parameters between the groups. We found a significant difference in the dislocation rate between the 2 groups, wherein there were no dislocations in the DM group and 3 dislocations in the HHS group (0% vs 6.4%). In terms of postoperative HHS at 12 months and 3 years, DM provided better outcomes (<0.034 and <0.014, respectively). DISCUSSION: Dual mobility compares favorably to HA in terms of dislocation rate and HHS, while no difference was found for FIM. In order to have a more complete overview, we recommend more intense long-term studies including several heterogeneous parameters to compare the clinical outcomes between DM and HA. LEVEL OF EVIDENCE (WITH STUDY DESIGN): Level II.