The increased torque required to dislocate dual mobility (DM) components may increase peri-prosthetic femoral fracture (PPF) risk. Current literature often relies on revision as an endpoint and may underestimate PPF. This study aims to review PPF rate, risks and treatment following primary DM implantation. Prospective cohort study of 549 patients following primary DM total hip arthroplasty (THA) between 2013 and 2021. Collected data included demographics, indication for surgery, cortical index and PPF. 549 patients were identified with primary DM THA. Mean age was 73 years (26–96). 446 (81.2%) patients had their index surgery following hip fracture. 18 patients (3.27%) sustained a PPF. Cumulative PPF rate was 1.5% at 1-year, 2.2% at 5-years and 3.27% overall. PPF was higher in patients undergoing surgery following hip fracture (4%) vs. other indications (1%). OR 4.04 (95% CI:0.53, 30.72), p=0.219. Mean cortical index was lower in patients with PPF 0.4 (95% CI:0.36, 0.45) compared to those without 0.46 (95% CI:0.45, 0.46) p=0.029. Treatment for PPF included 10 (55.6%) open reduction internal fixation (ORIF), 7 (38.9%) revision THA and 1 conservatively managed. PPF rate following DM use is higher in our cohort than published rates. Our rates are comparable to some papers when subgroup analysis of older patients and cemented taper slip stems are considered. PPF risk with DM may be increased in patients undergoing surgery after hip fracture or with a lower cortical index preoperatively. Over half of PPF were managed with ORIF and may mask PPF risk studies that report using revision as an endpoint.
Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility cup (DMC) and compare this with our previous series using the posterior lip augmentation device (PLAD). A retrospective review of patients treated with either a DMC or PLAD for dislocation in patients with a Charnley THA was performed. They were identified using electronic patient records (EPR). EPR data and radiographs were evaluated to determine operating time, length of stay, and the incidence of complications and recurrent dislocation postoperatively.Aims
Methods
Fractured neck of femur is a significant health concern within the UK. NICE guidance on the management of displaced intracapsular fractures states that total hip arthroplasty should be offered when patients can; walk independently out of doors with no more than a stick, not cognitively impaired, medically fit for anaesthesia and the procedure. We previously managed this subgroup using THA with standard sockets. Following an audit of this practice a dislocation rate of 9% was identified and practice was changed to using dual mobility (THA-DM) with the theoretical advantage of reducing dislocation. We reviewed all patients who underwent THA for fracture using Bluespier from 2013–2017. Operative notes and radiographs were reviewed to ensure the patients had undergone THA for displaced intracapsular fracture. Basic patient demographics were collected. Our primary outcome was dislocation rates at one year. Our secondary outcomes were length of time to surgery, length of stay, operative time, mortality, return to theatre rates and one year Oxford hip scores We found a control group of 45 THA procedures and a dual mobility group of 143 procedures. The one year dislocation rate from the THA-SS group was 9% and the THA-DM group was 1.4%(CI±1.9%)(p=<0.05%). There were also non-significant reductions in time to surgery, length of stay, operative time, mortality, return to theatre rates. The one year Oxford hip score was comparable at 42.2 to 41.8. This study demonstrates a significant reduction in one year dislocation rates with comparable oxford hip scores. Use of THA-DM should be considered in those patients who meet NICE criteria. Further research is needed into long term dislocation rates.
