Comparative study of total hip arthroplasties with dual mobility cups versus hemiarthroplasties in management of femoral neck fractures: Survival and dislocation rate at 5 years of follow-up?

Instability after hip arthroplasty, whether it is a total (THA) or intermediate (HA), poses a major risk, however arthroplasty is the standard treatment for displaced intracapsular fractures of the femoral neck of the elderly. Three types of arthroplasties can be proposed: total prostheses with or without a dual mobility cup (DM THA) reducing the risk of dislocation, and hemiarthroplasties. In the absence of clear recommendations regarding the type of implant to be used and the scarcity of studies comparing HA and DM THA, we conducted a monocentric comparative retrospective study using the propensity score method to compare DM THA versus HA on recently displaced femoral neck fractures: (1) survival and risk of dislocation, (2) functional results, (3) mortality. The rate of dislocation of THA fitted with a DM cup is lower than that of HA. We retrospectively identified 112 patients in the HA group and 153 patients in the DM THA group who underwent an emergency arthroplasty for a displaced cervical fracture between 2010 and 2013. The minimum follow-up was 5 years (range, 5-9 years). The mean age at surgery was 81 years (range, 55-101 years). Elective surgery patients (n=2), hardware fractures (n=10), pathological fractures of the femoral neck (n=6), associated fractures (n=3), and revision surgeries (n=5) were excluded. The primary outcome measure was instability. Clinical follow-up was performed by the WOMAC score and the risk of mortality was determined after adjusting for confounding factors using the propensity score method. After adjustment by the propensity score, the dislocation rate at 2-years was 2.2% (n=3/153) in the dual mobility THA group and 6.3% (n=7/112) in the HA group (OR=0.34 [95% CI: 0.06-1.96] (p=0.23)). After adjustment by the propensity score, the mean WOMAC score was 8.20 (±6.56) in the THA group, compared to 10.78±3.92 on average in the HA group (p=0.031). After adjustment by the propensity score, we did not find any significant difference in the reoperation rate without changing implants and revisions, and postoperative complications. After adjustment by the propensity score, mortality was significantly higher in the HA group 45.5% (n=69/152) versus 91.5% (n=102/112) in the HA group (OR=0.50 [95% CI: 0.25-0.98] (p=0.042)). Few studies have compared these two types of implant in the context of trauma. Although the results of our study are not significant regarding the risk of dislocation, the use of a dual mobility cup seems to be a very satisfactory solution in this trauma context. III; comparative retrospective cohort.

Bertault-Le Gourrierec J ，Cavaignac E ，Berard E ，Moretti F ，Marot V ，Chiron P ，Reina N ... -  《Orthopaedics & Traumatology-Surgery & Research》

Dual mobility total hip arthroplasty in the treatment of femoral neck fractures.

Cha YH ，Yoo JI ，Kim JT ，Park CH ，Ahn YS ，Choy WS ，Ha YC ，Koo KH ... -  《-》

Comparison of dual mobility total hip arthroplasty and bipolar arthroplasty for femoral neck fractures: A retrospective case-control study of 199 hips.

The choice between performing total hip arthroplasty (THA) or hemiarthroplasty (HA) is not straightforward in older patients with femoral neck fracture, particularly when co-morbidities are factored in. This led us to carry out a case-control study to determine (1) the rate of mechanical complications for these two types of implants, and (2) the rate of medical complications and mortality. THA with dual mobility cup (DM) will result in fewer mechanical complications than HA. This was a single-center, retrospective case-control study. Between 2010 and 2015, all patients with a femoral neck fracture treated by HA or DM THA were included. The primary outcome was the occurrence of any type of surgical complication. The Charlson Co-morbidity Index (CCI) and the independence during Activities of Daily Living (ADL) score were calculated for every patient. Two subgroups of patients were made based on whether they met frailty criteria. The effect of covariates on 1-year mortality was controlled using Cox's proportional hazards regression model. The cohort consisted of 101 HA and 98 THA procedures in 193 patients (139 women, 54 men) with a mean age of 80.6years (range, 76-101). The mean follow-up was 24.2months (range, 0-83) with a median of 14.5months. Fifteen of the HA hips (15%) had surgical complication, of which 10 were posterior dislocations (10%). Ten patients in the HA cohort had a serious medical complication (10%). Ten of the THA hips (10%) had a mechanical complication, including three posterior dislocations (3%) and four infections (4%). Nine patients in the THA cohort had a medical complication (9%). There were significantly fewer posterior dislocations in the THA hips (p = 0.05). In the subgroup analysis, the 117 patients (58%) who met the frailty criteria had a significantly lower dislocation rate after undergoing THA (p = 0.048). After adjusting on age, ADL and CCI score, the dislocation rate no longer differed significantly between the two groups (p = 0.1). The dislocation rate was lower in the THA hips only in the "frail" patients (Odds ratio = 0.137, 95% CI: [0.003-0.97] (p = 0.04)). There was no difference in the dislocation rate in the "non-frail" patients. The overall 1-year mortality was 85% [95% CI: 78-94%]. It was 78% [95% CI: 69-86%] for the HA hips and 88% [95% CI: 82-95%] for the THA hips (p = 0.01). After factoring in the impact of age, CCI and ADL, the differences in the 1-year mortality between HA and THA were no longer present (p = 0.42). Thus, there is no increased risk of mortality in THA patients. When the CCI and independence level are taken into consideration, the frailest patients can undergo DM THA to reduce the dislocation risk, without increasing the mortality rate at 1year. Patients who are not frail will benefit equally from undergoing HA or THA. III, case-control study.

Boukebous B ，Boutroux P ，Zahi R ，Azmy C ，Guillon P ... -  《Orthopaedics & Traumatology-Surgery & Research》

Total, hemi, or dual-mobility arthroplasty for the treatment of femoral neck fractures in patients with neurological disease : analysis of 9,638 patients from the Swedish Hip Arthroplasty Register.

Cnudde PHJ ，Nåtman J ，Hailer NP ，Rogmark C ... -  《-》

Outcomes of dual-mobility total hip arthroplasty versus bipolar hemiarthroplasty for patients with femoral neck fractures: a systematic review and meta-analysis.

Ma HH ，Chou TA ，Pai FY ，Tsai SW ，Chen CF ，Wu PK ，Chen WM ... -  《Journal of Orthopaedic Surgery and Research》