Outcomes and survival of a modern dual mobility cup and uncemented collared stem in displaced femoral neck fractures at a minimum 5-year follow-up.

INTRODUCTION: The choice of implant type for total hip replacement in the treatment of femoral neck fractures remains debated. Some authors advocate for the systematic use of cemented stems, while others do not use dual mobility first-line. We therefore conducted a retrospective study using a dual mobility cup (DMC) and an uncemented collared stem (UCS) in order to: (1) confirm the low dislocation rate in this indication, (2) assess other surgical complications, in particular periprosthetic fractures, (3) ensure that these benefits are maintained over time, at a minimum follow-up of 5 years and, (4) assess the rate of revision of the implants. HYPOTHESIS: Our hypothesis was that the dual mobility dislocation rate for the treatment of femoral neck fractures was lower than for bipolar hemiarthroplasties or single mobility hip prostheses. PATIENTS AND METHODS: A retrospective study of 244 femoral neck fractures (242 patients) treated with DMC and UCS was conducted, between 2013 and 2014. The mean age was 83±10 years (60-104). The occurrence of dislocation, periprosthetic fracture, infection of the surgical site, loosening, reoperation and revision were investigated. The HOOS Joint Replacement (JR) score was collected. The cumulative incidence with mortality was used as a competing risk. RESULTS: The mean follow-up was 6 years±0.5 (5-7). At the last follow-up, 108 patients (50%) had died. Twenty-three patients (9.5%) were lost to follow-up. One case of symptomatic aseptic loosening of DMC was observed. The cumulative incidence of dislocations and periprosthetic fractures at 5 years were 2% (95% CI: 0.9-5.4) and 3% (95% CI: 1.2-6), respectively. The 5-year cumulative incidence of surgical site infections was 3.5% (95% CI: 1.8-7). The cumulative incidence of reoperations at 5 years was 7% (95% CI: 4.5-11). The causes of reoperation were periprosthetic fracture (n=6), infection (n=8), postoperative hematoma (n=2) and cup malposition (n=2). The cumulative incidence of a revision at 5 years was 2.7% (95% CI: 1.2-6). The cumulative incidence of a surgical complication from any cause at 5 years was 9% (95% CI: 6.7-14.8). The mean HOOS JR score was 79±5 (52-92). DISCUSSION: The cumulative incidence of dislocation at 5 years is low and other surgical complications (including periprosthetic fractures) do not increase during this period for DMC associated with UCS, in femoral neck fractures. The use of this type of implant is reliable in the treatment of femoral neck fractures. LEVEL OF EVIDENCE: IV; retrospective study without control group.

Incidence and risk factors for bilateral proximal femoral fractures.

BACKGROUND: Proximal femoral fractures (PFFs) are a public health issue due to their high frequency. The frequency of a second PFF on the other side is estimated at 10%. This estimation is controversial, however, and the risk factors have not been evaluated in a large population of French patients. The objective of this retrospective case-control study was to determine: (1) the incidence of second PFFs and (2) their risk factors. HYPOTHESIS: The incidence of second PFFs is >2% after 1 year and >5% after 3 years. MATERIAL AND METHODS: We conducted a case-control study in a population of consecutive patients managed surgically for PPF at the Lyon Sud Hospital between 2013 and 2014. We analysed the following clinical factors: age, sex, body mass index (BMI), institutionalisation, the Parker score, the American Society of Anesthesiologists score (ASA), comorbidities, and the use of psychoactive drugs. RESULTS: We included 474 PFFs (trochanter, n=240 and neck, n=234) of which 36 were bilateral. The contralateral fracture occurred within 1 year of the first fracture in 6/474 (1.3%) cases and within 3 years in all 36 cases (7.6%). The case-control study comprised 49 cases with bilateral PFF and 161 controls with no second hip fracture within 3 years. Risk factors for a second hip fracture were age older than 90 years (odds ratio [OR]=5.44; 95% confidence interval [95%CI], 112-2642 (p=0.002)) and a history of heart disease (OR, 2.18; 95%CI, 1.06-4.47 [p=0.03]). A Parker score≥6 was protective (OR, 0.84; 95%CI, 0.71-0.99 [p=0.03]). Mortality after 3 years was 42% (201/474), and 13% (63/474) of patients were lost to follow-up. DISCUSSION: Age older than 90 years, a Parker score below 6, and a history of heart disease are risk factors for a second PFF within 3 years after the first PFF. LEVEL OF EVIDENCE: III; case-control study.

Return to Sport After Bilateral Single Stage Total Hip Arthroplasty Using the Direct Anterior Approach: A Case Control Study.

BACKGROUND: Total hip arthroplasty (THA) is currently performed on active patients with increasing functional demands. Single stage bilateral THA is indicated in younger patients in good general health. Our objective is to evaluate the return to sport (RTS) in patients who underwent bilateral single stage THA compared to unilateral THA. METHODS: This retrospective case control study was conducted between 2013 and 2017. All patients who underwent bilateral single stage THA were included. The control group had unilateral THA performed and was matched based on age, body mass index, gender, and surgery date (2 controls for each bilateral case). All surgeries were performed by a single senior surgeon using the direct anterior approach. The University of California Los Angeles activity score was collected at the last follow-up. A questionnaire regarding RTS, motivation, and satisfaction was assessed. RESULTS: Thirty-two patients were included in the study, of whom 21 were men. The average age was 60.7 ± 9.6 years, body mass index was 26 ± 4 kg/m2, and mean follow-up was 20.1 ± 11.6 months. Twenty-eight patients overall (87%) returned to sport after the procedure. Twenty-five of these (89%) returned to the same sport, and 17 (68%) participated at the same intensity. The average time to RTS was 4 ± 2.8 months. These results were at least as good as those after unilateral THA. The level of motivation of the patient was the only predictive factor for RTS (P < .001). CONCLUSION: Bilateral single stage THA via a direct anterior approach allows for RTS and to a similar level in the majority of patients in whom this procedure is indicated. LEVEL OF EVIDENCE: Comparative retrospective study, Level III.

Does acetabular dysplasia affect outcome in arthroscopic treatment of cam femoroacetabular impingement? Case-control study with and without acetabular dysplasia.

BACKGROUND: Arthroscopic management of femoroacetabular impingement (FAI) is classically contraindicated when acetabular dysplasia is associated, although this is controversial in case of moderate dysplasia or isolated cam effect. A case-control study was therefore conducted comparing borderline (center-edgeangle (CEA), 20-24°), moderate (15-19°) and severe dysplasia (<15°) (group D) versus a control group with normal acetabular cover (CEA, 25-30°). The aims were 1) to determine functional results and satisfaction, and 2) to correlate functional results with severity of dysplasia and of cam effect. HYPOTHESIS: Improvement in functional scores and satisfaction is lower in group D than in controls, due to non-correction of dysplasia. MATERIAL AND METHOD: A single-center, single-surgeon retrospective comparative case-control study included all patients with isolated cam-effect FAI and dysplasia but without osteoarthritis (group D) or with isolated cam-effect FAI without dysplasia (controls) operated on during the study period. Cases of mixed impingement were excluded. Preoperative and last-follow-up functional variables included McCarthy's modified Harris Hip Score (mHHS) and Christensen's Non-Arthritic Hip Score (NAHS). RESULTS: Between 2011 and 2014, details of 407 patients operated on by arthroscopy were entered in a data-base. Twenty patients (22 hips) were included in group D, with CEA<25° (mean, 19±3.1; range, 10-23°). The control group comprised 23 patients (25 hips) with CEA>25° (mean, 29±2.1°; range, 25-30°) matched for gender, age and body-mass index. Mean follow-up was 29.6±14.1 months (range, 14-58 months) in group D and 31.4±10.6 months (range, 15-57 months) in the control group (p=0.66). For functional scores, the two groups showed respectively 9.9 (-34 to +47) (p=0.038) and 10.4 (-20 to +48) (p=0.0038) gain in mHHS (non-significant: p=0.943). Mean gain in NAHS was 16.6 (-19 to +33) (p=0.0001) and 13.7 (-11 to +47) (p=0.0002), respectively (non-significant: p=0.56) CONCLUSION: Short-term functional results for cam FAI treatment were equivalent with<25° acetabular cover (mean, 19°; range, 13-24°) or normal cover. Longer-term assessment is indispensable to determine the impact of dysplasia and its severity. LEVEL OF EVIDENCE: III, case-control study.