The concept of stainless steel dual mobility cups in total hip arthroplasty has demonstrated very low long-term instability rates and a 98% survival rate after 12 years. We systematically implanted titanium alloy acetabular cups during a one year period. The purpose of our retrospective study was to report the 18-year clinical outcome data in a homogeneous and continuous series of 103 primary total hip replacements after implantation of a cementless titanium cup. All patients were implanted with NOVAE Ti (SERF) cups made of titanium alloy combined with a retentive polyethylene liner and a 22.2 mm cobalt chrome prosthetic head. Mean patient age at the time of surgery was 53 years. All patients were clinically and radiographically evaluated. The overall 18-year actuarial cup survival rate with a 95% confidence interval was 87.4%. At last follow-up, there was no evidence of implant instability whereas acetabular aseptic loosening was reported in one case and high wear of the retentive liner in 9. The results of this investigation confirmed the long-term stability of dual-mobility implants. The main limitation of this system was early wear of the polyethylene liner in contact with the titanium metal back and reaction with third body along with loss of liner retentivity. In our study, titanium demonstrated favourable osteointegration properties but poor tribologic characteristics, therefore suggesting its interest at the bone-cup interface only

Introduction. Although femoral neck fractures remain a concern in short term failures for hip resurfacing, acetabular component position and fixation are increasingly being recognized as causes of mid term failures for hip resurfacing. This study aimed to evaluate the migration pattern of a cobalt chrome, beaded acetabular component for a metal on metal hip resurfacing. Methods. 130 patients underwent metal on metal hip resurfacing: 66 hips in 60 patients had sufficient films to be included in this analysis. Forty-eight patients were male and 12 were female, with a mean age of 50 (range, 32–66). Ninety-five percent of the procedures were performed for osteoarthritis. In all cases acetabular migration was measured both vertically and horizontally, on serial radiographs using the computer-assisted Ein Bild Röntgen Analyse method. A minimum of three comparable radiographs is necessary for calculating the migration curves. We scored medial migration as negative horizontal movement. Results. At a mean follow up 25.3 months (24–36 months), each hip had an average of 5.1 radiographs for analysis. 12.5% of the cups showed more than 1 mm migration in the medial-lateral axis and 45.3% more than 1 mm in the vertical axis. 23% of the cups showed a combined migration of greater than 2 mm in the observation period. Two of these cases required revision for aseptic loosening at 34 months. Discussion and Conclusion. Previous studies have shown EBRA to have an excellent sensitivity and positive predictive value for mid to long term cup failure. This data raises concern about the initial stability if this acetabular component. Continued follow-up is needed to monitor the longer term survival of this implant

Introduction. Oxidized zirconium (OxZr) is used as a ceramic surface for femoral components in total knee arthroplasty (TKA). The aim of this study was to investigate its performance by examining retrieved femoral components and their corresponding PE inserts in matched comparison with conventional chrome/cobalt/molybdenum alloy (CrCoMo). Methods. 11 retrieved posterior stabilized (PS) TKA with an OxZr femoral component were included. From a cohort of 56 retrieved TKA with CrCoMo femoral components, pairs were matched according to duration of implantation, patient age, reason for revision, and BMI. The retrieved tibial polyethylene (PE) inserts were analyzed for wear using the Hood classification. Femoral components were optically viewed at 8–32x magnification and screened for scratching, pitting, delamination, and striation. Profilometry was performed to measure surface roughness of the OxZr components using a non-contact white light profiler. Results. The prostheses were in situ for a mean of 18.5±10.6 (OxZr) and 19.5±14.3 (CrCoMo) months (p=0.41). None of these cases were revised for problems directly related to the use of OxZr. There was one reaction to the implant in the CrCoMo group. The average wear of the tibial PE inserts was significantly lower with OxZr components (41.5±16.8 vs. 60.1±22.0, p=0.01). The average wear score in the visual analysis of the femoral components was significantly lower for the OxZr (1.6±1.3 vs. 9.5±0.6, p=0.005). Discussion and Conclusion. Femoral components made of OxZr are less sensitive to in vivo wear damage than those of CrCoMo. PE inlays show significantly less in vivo wear damage in combination with an OxZr femoral component

Introduction. Cobalt chrome on polyethylene remains a widely used bearing combination in total joint replacement. However wear induced osteolysis, bulk material property degradation of highly cross-linked polyethylene (HXLPE) [1], and oxidation after implantation (thought to be as a result of lipid absorption or cyclic loading [2]) remains a concern. ECIMA is a cold-irradiated, mechanically annealed, vitamin E blended next generation HXLPE developed to maintain mechanical properties, minimise wear and to improve the oxidation resistance in the long-term. The aim of this study was to compare the in-vitro wear rate and mechanical properties of three different acetabular liners; conventional UHMWPE, HXLPE and ECIMA. Methods. Twelve liners (Corin, UK) underwent a 3 million cycle (mc) hip simulation. Three conventional UHMWPE liners (GUR1050, Ø32 mm, 30 kGy sterilised in Nitrogen), three HXLPE liners (GUR1020, Ø40 mm, 75 kGy cross-linking and EtO sterilised) and six ECIMA liners (0.1 wt% vitamin E GUR1020, Ø40 mm, 120 kGy cross-linking, mechanically deformed and annealed, and EtO sterilised) articulated against CoCrMo alloy femoral heads to ASTM F75 (Corin, UK). Wear testing was performed in accordance with ISO 14242 parts 1 and 2, with a maximum force of 3.0 kN and at a frequency of 1 Hz. The test lubricant used was calf serum with a protein content of 30 g/l and 1% (v/v) patricin added as an antibacterial agent. Volumetric wear rate was determined gravimetrically after the first 0.5 mc and every 1 mc thereafter. ASTM D638 type V specimens (3.2 mm thick) were machined from ECIMA material for uniaxial tension testing to ASTM D638. Ultimate tensile strength (UTS), yield strength and elongation values were measured. These values were compared to mechanical data available for the other material types. Results. There was a 94% and a 68% reduction in the wear rate for the ECIMA liners compared to the conventional UHMWPE and HXLPE liners respectively. There was an increase in UTS, yield strength and elongation of 11%, 11% and 15% respectively, for ECIMA compared to HXLPE. Discussion. The wear results reported in this study indicate that ECIMA is a very low wearing material which has the potential to reduce wear related osteolysis in-vivo. Importantly, the mechanical properties were generally maintained unlike the degradation found in many modified polyethylene materials and were more comparable to conventional UHMWPE than HXLPE. The reduced wear rate during in-vitro hip simulation of ECIMA compared to conventional UHMWPE, coupled with improved mechanical properties in comparison to HXLPE, makes ECIMA a promising next generation, advanced bearing material

Aims

This study sought to determine the proportion of older adults with hip fractures captured by a multicentre prospective cohort, the World Hip Trauma Evaluation (WHiTE), whether there was evidence of selection bias during WHiTE recruitment, and the extent to which the WHiTE cohort is representative of the broader population of older adults with hip fractures.

Aims

Periprosthetic femoral fractures (PFF) following total hip arthroplasty (THA) are devastating complications that are associated with functional limitations and increased overall mortality. Although cementless implants have been associated with an increased risk of PFF, the precise contribution of implant geometry and design on the risk of both intra-operative and post-operative PFF remains poorly investigated. A systematic review was performed to aggregate all of the PFF literature with specific attention to the femoral implant used.