Introduction:. The treatment of 3- or 4-part proximal humeral fractures in elderly can be carried out with hemiarthroplasty. Also hemiarthroplasty has performed for failed osteosynthesis or conservative treatment in Japan. However the secondary hemiarthroplasty has poor clinical outcome. The aim of this study was to compare the clinical outcomes of primary and secondary hemiarthroplasty for proximal humeral fractures. Materials and Methods:. Between March 2004 and January 2013, twenty-four shoulders in 23 patients (22 females, 1 male) with proximal humeral fractures and fracture dislocations underwent hemiarthroplasty. The mean age was 75.6 years and the average follow-up period was 25.6 months (range 3 to 108 months). Eighteen shoulders in 17 patients were treated primary with hemiarthroplasty (primary group). Six shoulders in 6 patients were treated with hemiarthroplasty after other treatments had failed (secondary group). All patients were evaluated with the Japan Orthopaedic Association shoulder scoring system (JOA score) and range of motion. Results:. The mean JOA score was 66.7 points in primary group and 50.6 points in secondary group. Patients in primary group had significantly better score than secondary group (p < 0.05). At the final follow-up, the mean flexion angle was 81.4 degrees in primary group and 55.0 degrees in secondary group. The mean abduction angle was 79.7 degrees in primary group and 46.7 degrees in secondary group. The mean external rotation angle was 16.1 degrees in primary group and 5.0 degrees in secondary group. There was a significant difference in abduction angle between primary and secondary group (p < 0.05). On the other hand there was no significant difference in flexion and external rotation angle between primary and secondary group (p = 0.10, 0.03). Conclusions:. In this study primary group demonstrated good clinical results rather than in secondary group. Secondary hemiarthroplasty for failed early treatment is technically difficult. Important factors for secondary hemiarthroplasty include the reconstruction of tuberosities and technique to treat soft tissues such as deltoid gently

Objectives. Distal humerus fractures in elderly population are often comminuted and presents multiple challenges. When managed with fixation the results are often complicated with stiffness, pain, and reduced function while total elbow replacement is fraught with lifelong restrictions on load bearing which can significantly affect elderly patients who rely assistive devices for ambulation. Elbow hemiarthroplasty however, presents a viable alternative in these cases. This series evaluates the results of the distal humerus hemiarthroplasty in a single centre. Designs and methods. Data was collected retrospectively. Comprehensive case reviews were done to collect demographic, intra-operative and post-operative data. Fractures were classified as per AO classification. The primary outcome was functional outcome and range of motion (ROM). The secondary outcomes were complications and patient satisfaction. Results. 22 cases were included in this study from 2016 – 2023 majority being females (n=18). Mean age was 74years (SD −11.2). Majority fractures were AO type C3 (n=15) with two A2 type fractures managed for non-union. Pre-existing bone on bone arthritis was present in 3 cases and CT scan was done for 12 patients to assess fracture configuration. Excluding those treated for non- union the median time between fracture and surgery was 8.5 days. Follow-up of more than 6 months was available for 16 patients with median follow-up of 18 months. ROM was available for 17 patients with 13 (50%) patients having functional ROM. No patients had full extension and there was a mean lag of 20. 0. Mean flexion was 118.2. 0. Nearly 2/3. rd. patients (73%- n=16) were satisfied with the surgery with no problems in activity of daily living. Complications seen were ulnar neuropathy (n=3), heterotopic ossification(n=2) and periprosthetic fracture (n=1). Conclusion. This single centre study suggests good outcomes following distal humerus hemiarthroplasty. It is a reasonable alternative to fixation and total elbow arthroplasty in complex fractures

Abstract. Background. Dislocation of a hip hemiarthroplasty is a devastating complication with a high mortality rate in elderly patients. Previous studies have suggested a higher dislocation rate in patients with neuromuscular conditions. In this study, we have reviewed our larger cohort of patients to identify whether there is any association between neuromuscular disorders and prosthetic dislocation in patients treated with hip hemiarthroplasty for femoral neck fractures. Patients and Methods. Our study is a retrospective analysis of data collected over 34 years for patients with intracapsular neck of femur fracture who underwent hip hemiarthroplasty. The study population is composed of four groups: patients with no neuromuscular disorders, patients with Parkinson's disease, patients with previous stroke, and patients with dementia. Results. A total of 3827 patients were treated with hip hemiarthroplasty. For the 3371 patients with no neuromuscular condition (Group I) the dislocation rate was 1.1%. 219 patients had Parkinsonism (Group II) with a dislocation rate of 3.2%, 104 patients had a previous stroke with weakness on the fracture side with a dislocation rate of 1.0% (Group III), and 984 patients had severe dementia with a dislocation rate of 1.8% (Group IV). The increased dislocation rate for those with Parkinson's disease was statistically significant (p=0.02) while none of the other neuromuscular conditions were statistically significant. Conclusion. Our study demonstrates an increased risk of dislocation after hemiarthroplasty for patients with Parkinson's disease in comparison to other groups. No increase was apparent for those with dementia or weakness from a previous stroke

Hemiarthroplasty is a common procedure that is an attractive alternative to total arthroplasty because it conserves natural tissue, allows for quicker recovery, and has a lower cost. One significant issue with hemiarthroplasties is that they lead to accelerated wear of the opposing native cartilage, likely due to the high stiffness of the implant. The purpose of this study was to investigate the range of currently available biomaterials for hemiarthroplasty applications. We employed a finite-element (FE) model of a radial head implant against the native capitellum as our joint model. The FE model was developed in ABAQUS v6.14 (Dassault Systèmes Simulia Corp., Providence, RI, USA). A solid axisymmetric concave implant with seven different materials and the native radial head were evaluated, six modelled as elastic materials with different Young's moduli (E) and Poisson's Ratios (ν), and one modelled as a Mooney-Rivlin hyperelastic material. The materials investigated were CoCr (E=230 GPa, ν = 0.3), PEEK (E=3.7 GPa, ν = 0.36), HDPE (E=2.7 GPa, ν = 0.42), UHMWPE (E=0.69 GPa, ν = 0.49), Bionate 75D (E=0.288 GPa, ν = 0.39), Bionate 55D (E=0.039 GPa, ν = 0.45), and Bionate 80A (modelled as a Mooney-Rivlin hyperelastic material). A load of 100 N was applied to the radius through the center of rotation representing a typical load through the radius. The variable of interest was articular contact stress on the capitellum. The CoCr implant had a maximum contact stress over 114% higher than the native radial head. By changing the material to lower the stiffness of the implant, the maximum contact stress was 24%, 70%, 105%, 111%, 113%, and 113% higher than the native radial head for Bionate 80A, Bionate 55D, Bionate 75D, UHMWPE, HDPE, and PEEK respectively. This work shows that lowering implant stiffness can reduce the contact stress on cartilage in hemiarthroplasty implants. By changing the material below a Young's modulus of ∼100 MPa elevated stresses on the capitellum can be markedly reduced and hence potentially reduce or prevent degenerative changes of the native articulating cartilage. Low stiffness implant materials are not a novel concept, but to date there have been few that investigate materials (such as Bionate) as a potential load bearing material for implant applications. Further work is required to assess the efficacy of these materials for articular bearing applications

Background. Hip Hemiarthroplasty is one of the commonest orthopaedic operation done in UK with recent NHFD data from 2017 report showing that 43% of the 77000 patients who presented to hospital had hemiarthroplasty. Literature suggests dislocation rate of 0.8% – 6.1% for Hip Hemiarthroplasty. Dislocation of hemiarthroplasty may lead to significant morbidity and mortality. Aim. To investigate if acetabular dysplasia has a significant association with hemiarthroplasty dislocation. Methodology. Retrospective multicentre review. Review of radiographs of patients receiving a hip hemiarthroplasty for a hip fracture measuring Acetabular index (sharp angle) and Lateral Centre edge angle(CEA). A large acetabular index and lower value for the center-edge angle suggest acetabular dysplasia. Measurements were made for 20 patients with dislocation and 20 patients without dislocation. Statistical assessment of the results with unpaired t test was performed. Results. Mean acetabular angle for those with dislocation was 42.65 degrees versus 37.8 for those without dislocation giving a p value of 0.000861. Mean Center-edge angle of those with dislocation was 26.1 degrees versus 37 for those without dislocation giving a p value of 0.000019. Conclusion. This study showed that the hemiarthroplasty dislocation group had higher acetabular index and Lower Center-edge angle compared to the hemiarthroplasty group without dislocation clearly demonstrating that acetabular dysplasia is implicated in the aetiology of hip hemiarthroplasty dislocation. Hence careful review of the pre-op X-rays for dysplastic features would benefit in making a sound management plan

Prosthetic joint infections (PJI) are devastating complications. Our knowledge on hip fractureassociated hemiarthroplasty PJI (HHA-PJI) is limited compared to elective arthroplasty. The goal of this study was to describe the epidemiology, risk factors, management, and outcomes for HHA-PJI. A population-based (465,000) multicentre retrospective analysis of HHAs between 2006-2018 was conducted. PJI was defined by international consensus and treatment success as no return to theatre and survival to 90 days after the initial surgical management of the infection. Univariate, survival and competing risk regression analyses were performed. 1852 HHAs were identified (74% female; age:84±7yrs;90-day-mortality:16.7%). Forty-three (2.3%) patients developed PJI [77±10yrs; 56% female; 90-day-mortality: 20.9%, Hazard-Ratio 1.6 95%CI 1.1-2.3,p=0.023]. The incidence of HHA-PJI was 0.77/100,000/year and 193/100,000/year for HHA. The median time to PJI was 26 (IQR 20-97) days with 53% polymicrobial growth and 41% multi-drug resistant organisms (MDRO). Competing risk regression identified younger age [Sub-Hazard-Ratio(SHR) 0.86, 95%CI 0.8-0.92,p<0.001], chronic kidney disease (SHR 3.41 95%CI 1.36-8.56, p=0.01), body mass index>35 (SHR 6.81, 95%CI 2.25-20.65, p<0.001), urinary tract infection (SHR 1.89, 95%CI 1.02-3.5, p=0.04) and dementia (SHR 9.4, 95%CI 2.89-30.58,p<0.001) as significant risk factors for developing HHA-PJI. When infection treatment was successful (n=15, 38%), median survival was 1632 days (IQR 829-2084), as opposed to 215 days (IQR 20-1245) in those who failed, with a 90-day mortality of 30%(n=12). There was no significant difference in success among debridement, excision arthroplasty or revision arthroplasty. HHA PJI is uncommon but highly lethal. All currently identified predictors are non-modifiable. Due to the common polymicrobial and MDRO infections our standard antibiotic prophylaxis may not be adequate HHA-PJI is a different disease compared to elective PJI with distinct epidemiology, pathogens, risk factors and outcomes, which require targeted research specific to this unique population

Recent NICE guidelines have suggested abandoning the Thompson hemiarthroplasty (TH) in favour of a ‘proven prosthesis’ such as the Exeter Trauma Stem (ETS). This is controversial because of significant cost implications and limited research assessing outcomes of the ETS. The aim of this study was to assess the treatment of intracapsular neck of femur fractures with the TH. Between 2002 and 2006 (minimum 5 year follow-up), 431 cemented TH's were performed. Death rate at 1 year and 5 years were 26.0% and 67.7% respectively. Dislocation (1.4%) and infection (0.2%) rates were low and revision rate was 1.2%. Comparison was made to Bipolar hemiarthroplasties over the same period (total 194). These had lower rates of dislocation (0.5%) and infection (0.5%) with a significantly higher (3.6%) revision rate. We feel that the TH remains the current gold standard treatment for intracapsular fractures, in appropriate patients, due to low complication and revision rates. Modern implants may provide better function or longevity, but there is no evidence in the literature to support abandoning the TH. Surgeons should assess patients and decide on its use, despite NICE guidelines, as it remains a cost effective treatment method, particularly for older, less mobile and cognitively impaired patients

Joint hemiarthroplasty replaces one side of a synovial joint and is a viable alternative to total joint arthroplasty when one side of the joint remains healthy. Most hemiarthroplasty implants used in current clinical practice are made from stiff materials such as cobalt chrome or ceramic. The substitution of one side of a soft cartilage-on-cartilage articulation with a rigid implant often leads to damage of the opposing articular cartilage due to the resulting reductions in contact area and increases in cartilage stress. The improvement of post-operative hemiarthroplasty articular contact mechanics is of importance in advancing the performance and longevity of hemiarthroplasty. The purpose of the present study was to investigate the effect of hemiarthroplasty surface compliance on early in-vitro cartilage wear and joint contact mechanics. Cartilage wear tests were conducted using a six-station pin-on-plate apparatus. Pins were manufactured to have a hemispherical radius of curvature of 4.7 mm using either Bionate (DSM Biomedical) having varying compliances (80A [E=20MPa], 55D [E=35MPa], 75D [E=222MPa], n=6 for each), or ceramic (E=310GPa, n=5). Cartilage plugs were cored from fresh unfrozen bovine knee joints using a 20 mm hole saw and mounted in lubricant-containing chambers, with alpha calf serum diluted with phosphate buffer solution to a protein concentration of 17 g/L. The pins were loaded to 30N and given a stroke length of 10 mm for a total of 50,000 cycles at 1.2 Hz. Volumetric cartilage wear was assessed by comparing three-dimensional cartilage scans before and during wear testing. A two-way ANOVA was used for statistical analysis. To assess hemiarthroplasty joint contact mechanics, 3D finite element modelling (ABAQUS v6.12) was used to replicate the wear testing conditions. Cartilage was modeled using neo-Hookean hyper-elastic material properties. Contact area and peak contact stress were estimated. The more compliant Bionate 80A and 55D pins produced significantly less volumetric cartilage wear compared with the less compliant Bionate 75D and ceramic pins (p 0.05). In terms of joint contact mechanics, the more compliant materials (Bionate 80A and 55D) had significantly lower maximum contact stress levels compared to the less compliant Bionate 75D and ceramic pins (p < 0 .05). The results of this study show a relationship between hemiarthroplasty implant surface compliance and early in vitro cartilage wear, where the more compliant surfaces produced significantly lower amounts of cartilage wear. The results of the joint contact mechanics analysis showed that the more compliant hemiarthroplasty materials produced lower maximum cartilage contact stresses than the less compliant materials, likely related to the differences in wear observed. More compliant hemiarthroplasty surfaces may have the potential to improve post-operative cartilage contact mechanics by increasing the implant-cartilage contact area while reducing peak contact stress at the implant-cartilage interface, however, such materials must be resistant to surface fatigue and longer-term cartilage wear/damage must be assessed

Abstract. Background. To determine the long-term survival outcomes of Copeland Resurfacing Hemiarthroplasty (CRHA) performed by a single surgeon series. Methods. A retrospective cohort study which looked at patients who underwent CRHA over 6 years. Re-operations including revisions with component exchange taking place in our hospital and at local centres were reviewed. Oxford Shoulder Score (OSS) was used to assess their functional outcomes pre- and post-CRHA. Results. 80 CRHAs were performed in 72 patients between 2007 and 2013 with a mean follow-up of 6.5 years. The mean follow-up was 79 months (50–122). The primary indication for CRHA was osteoarthritis (76.3%), cuff tear arthropathy (16.3%), rheumatoid arthritis (5%) and post-trauma (1.3%). The mean pre-operative OSS was 16, which doubled following CRHA surgery. Fifteen patients underwent revision surgery due to ongoing glenoid pain with a mean revision time following primary CRHA being 49 months. Projected survival at the endpoints 5,7 and 10 years were 83, 81 and 79% respectively. Conclusion. This study provides us with a much longer average follow-up period in comparison to many other studies published. Previous studies, support resurfacing as a useful implant in reducing pain and improving function in the short-term; but this series demonstrates over the medium-term a relatively high revision rate of about 20% in comparison with other arthroplasty options, despite the revision rate seeming to plateau from the 5-year mark onwards

Gram-negative prosthetic joint infections (GN-PJI) present unique challenges in management due to their distinct pathogenesis of biofilm formation on implant surfaces. To date, there are no animal models that can fully recapitulate how a biofilm is challenged in vivo in the setting of GN-PJI. The purpose of this study is to establish a clinically representative GN-PJI in vivo model that can reliably depict biofilm formation on titanium implant surface. We hypothesized that the biofilm formation on the implant surface would affect the ability of the implant to be osseointegrated. The model was developed using a 3D-printed, medical-grade titanium (Ti-6Al-4V), monoblock, cementless hemiarthroplasty hip implant. This implant was used to replace the femoral head of a Sprague-Dawley rat using a posterior surgical approach. To induce PJI, two bioluminescent Pseudomonas aeruginosa (PA) strains were utilized: a reference strain (PA14-lux) and a mutant strain that is defective in biofilm formation (DflgK-lux). PJI development and biofilm formation was quantitatively assessed in vivo using the in vivo imaging system (IVIS), and in vitro using the viable colony count of the bacterial load on implant surface. Magnetic Resonance Imaging (MRI) was acquired to assess the involvement of periprosthetic tissue in vivo, and the field emission scanning electron microscopy (FE-SEM) of the explanted implants was used to visualize the biofilm formation at the bone-implant interface. The implant stability, as an outcome, was directly assessed by quantifying the osseointegration using microCT scans of the extracted femurs with retained implants in vitro, and indirectly assessed by identifying the gait pattern changes using DigiGaitTM system in vivo. A localized prosthetic infection was reliably established within the hip joint and was followed by IVIS in real-time. There was a quantitative and qualitative difference in the bacterial load and biofilm formation between PA14 and DflgK. This difference in the ability to persist in the model between the two strains was reflected on the gait pattern and implant osseointegration. We developed a novel uncemented hip hemiarthroplasty GN-PJI rat model. This model is clinically representative since animals can bear weight on the implant. PJI was detected by various modalities. In addition, biofilm formation correlated with implant function and stability. In conclusion, the proposed in vivo GN-PJI model will allow for more reliable testing of novel biofilm-targeting therapetics

Introduction. Gram-negative prosthetic joint infections (GN-PJI) present unique challenges in management due to their distinct pathogenesis of biofilm formation on implant surfaces. The purpose of this study is to establish a clinically representative GN-PJI model that can reliably recapitulate biofilm formation on titanium implant surface in vivo. We hypothesized that biofilm formation on an implant surface will affect its ability to osseointegrate. Methods. The model was developed using 3D-printed titanium hip implants, to replace the femoral head of male Sprague-Dawley rats. GN-PJI was induced using two bioluminescent Pseudomonas aeruginosa strains: a reference strain (PA14-lux) and a mutant biofilm-defective strain (ΔflgK-lux). Infection was monitored in real-time using the in vivo imaging system (IVIS) and Magnetic Resonance Imaging (MRI). Bacterial loads on implant surface and in periprosthetic tissues were quantified utilizing viable-colony-count. Field-emission scanning-electron-microscopy of the explanted implants was used to visualize the biofilm formation at the bone-implant-interface. The implant stability, as an outcome, was directly assessed by quantifying the osseointegration in vitro using microCT scan, and indirectly assessed by identifying the gait pattern changes using DigiGait. TM. system in vivo. Results. Localized infection was established within the hip joint and was followed by IVIS in real-time. There was a quantitative and qualitative difference in the bacterial load and biofilm formation between PA14-lux and ΔflgK-lux. This difference in the ability to persist in the model between the two strains was reflected in the gait pattern and implant osseointegration. Conclusions. We developed a novel uncemented hip hemiarthroplasty, GN-PJI rat model. To date, the proposed in vivo biofilm-based model is the most clinically representative for GN-PJI since animals can bear weight on the implant and poor osseointegration correlates with biofilm formation. In addition, localized PJI was detected by various modalities. Clinical Relevance. The proposed in vivo GN-PJI model will allow for more reliable testing of novel biofilm-targeting therapeutics

Introduction. Geometric variations of the hip joint can give rise to abnormal joint loading causing increased stress on the articular cartilage, which may ultimately lead to degenerative joint disease. In-vitro simulations of total hip replacements (THRs) have been widely reported in the literature, however, investigations exploring the tribology of two contacting cartilage surfaces, and cartilage against metal surfaces using complete hip joint models are less well reported. The aim of this study was to develop an in-vitro simulation system for investigating and comparing the tribology of complete natural hip joints and hemiarthroplasties with THR tribology. The simulation system was used to assess natural porcine hip joints and porcine hemiarthroplasty hip joints. Mean friction factor was used as the primary outcome measure to make between-group comparisons, and comparisons with previously published tribological studies. Method. In-vitro simulations were conducted on harvested porcine tissue. A method was developed enabling natural acetabula to be orientated with varying angles of version and inclination, and natural femoral heads to be potted centrally with different orientations in all three planes. Acetabula were potted with 45° of inclination and in the complete joint studies, natural femoral heads were anatomically matched and aligned (n=5). Hemiarthroplasty studies (n=5) were conducted using cobalt chrome (CoCr) heads mounted on a spigot (Figure 1), size-matched to the natural head. Natural tissue was fixed using PMMA (polymethyl methacrylate) bone cement. A pendulum friction simulator (Simulator Solutions, UK), with a dynamic loading regime of 25–800N, ± 15° flexion-extension (FE) at 1 Hertz was used. The lubricant was a 25% (v/v) bovine serum. Axial loading and motion was applied through the femoral head and frictional torque was measured using a piezoelectric transducer, from which the friction factor was calculated. Results. The correct anatomical orientation and positioning was achieved enabling in-vitro simulation testing to be conducted on hemiarthroplasty and complete hip joint samples for two-hours. Mean friction increased rapidly followed by a continued gradual increase to ≈0.03 ± 0.00 in the complete joints, with the hemiarthroplasty group plateauing at ≈0.05 ± 0.01 (Figure 2). Mean friction factor was significantly lower (t-test; p < 0.05) in the complete natural joint group. Discussion. An in-vitro simulation system for the natural hip joint with controlled orientation of the femur and acetabulum was successfully developed and used to measure friction in complete porcine hip joints and porcine hip hemiarthroplasties. A non-linear increase in friction indicative of biphasic lubrication was observed in both groups with slower exudation of fluid from the complete joints compared to the hemiarthroplasties, inferring a quicker move towards solid-phase lubrication. Higher friction in the hemiarthroplasties, which was similar to that measured in-vitro in metal-on-polyethylene THRs, was most likely due to variable clearances between the non-conforming spherical metal head and aspherical acetabulum, causing poorer congruity and distribution of the load. This could in time lead to abrasive wear and cartilage degradation. This methodology could have an important role when investigating associations between hip geometric variations, interventions for hip disease/pathology, and risk factors for cartilage degeneration

Background. Hemiarthroplasty of the hip involves the replacement of the femoral side of the joint with a metal prosthesis, resulting in metal-on-cartilage articulation. The two most common types of hemiarthroplasty used are the Austin Moore and the Thomson, both of which are available in either Titanium (Ti) or cobalt chromium (CoCr). Hemiarthroplasty may be more cost effective in elderly patients who have lower life expectancy and are less active. Materials and Methods. Three Ti and two CoCr hemiarthroplasty components were obtained following revision surgery. Four had an articulating diameter of 44mm and the other was 46mm diameter. These five hemiarthroplasties were analysed using a Mitutoyo LEGEX322 co-ordinate measuring machine (CMM) (manufacturer's claimed scanning accuracy of 0.8μm). In each case a wear map was generated and the wear volume from the articulating surface was calculated using a bespoke MATLAB program. Results. The two CoCr prostheses had wear volumes of 1.3mm. 3. and 7.8mm. 3. , while the three Ti prostheses had wear volumes of 85.4 mm. 3. , 16.3 mm. 3. and 17.4 mm. 3. . Figure 1: CoCr Prosthesis with a small wear scar at the rim. Figure 1 shows the location of the wear mark on the bottom edge of the CoCr prosthesis, with a volumetric wear of 1.3 mm. 3. , and also some scratching at the pole. The maximum wear depth was 0.0082mm. The second CoCr prosthesis also showed small localised wear marks over the surface and at the pole giving a total wear volume of 7.8mm. 3. and a maximum linear wear depth of 0.016mm. Figure 2: Ti Prosthesis with large wear. Figure 2 shows the Ti prosthesis with the highest wear volume of 85.4 mm. 3. The worn area (shown in blue) extended over much of the articulating surface area and the maximum linear depth was 0.080mm. The second Ti prosthesis (the only sample of 46mm diameter) had a wear volume of 16.3 mm. 3. and a maximum linear wear depth of 0.045mm. Figure 3: Ti Prosthesis with wear mark at the pole. The third Ti prosthesis analysed (shown in Figure 3) had a wear volume of 17.36 mm. 3. Unlike the others the wear was concentrated at the pole where the linear wear depth was 0.060mm. Discussion. To the authors' best knowledge they are unaware of any other volumetric wear studies on explanted hemiarthroplasties. The CoCr hemiarthroplasties showed lower wear volumes and smaller linear wear depths than the Ti prostheses. The location of the wear marks on the articulating surface varied between the retrieved prostheses. These results suggest that Ti hemiarthroplasties are wearing more than CoCr prostheses. It is unknown what effect the two different types of prostheses have upon the cartilage of the acetabulum, or whether there is any difference in the damage they cause. Given the results obtained, and the known negative effects of particulate wear debris in the body questions should be asked regarding the suitability of Ti for use in hemiarthroplasty

Purpose. Capitellum hemiarthroplasty is an emerging concept. The current metallic capitellar implants have spherical surface shapes, but the native capitellum is not spherical. This study evaluated the effect of capitellar implant shape on the contact mechanics of the radiocapitellar joint when articulating with the native radial head. Method. Eight paired radii and humeri were potted in a custom jig. Articular casts were made with medium-viscosity resin while 85 N of axial load was applied to the reduced radiocapitellar joint at 0, 45, and 90 of elbow flexion, and at neutral, 50 pronation and 50 supination at each flexion angle. The native radiocapitellar articulation was compared to capitellar hemiarthroplasties of two surface designs (anatomical and spherical). Contact area and shape (circularity) were determined. Circularity was defined as the ratio of the minor axis and major axis of the shape. Results. At 0 of flexion, the anatomical hemiarthroplasty had a contact area of 52–70% that of the native articulation (p=0.03), while the spherical hemiarthroplasty had a contact area 40–42% that of the native articulation (p=0.003). At 45 of flexion, both hemiarthroplasties displayed contact area <53% that of the native joint (p<0.007). At 90 of flexion, the hemiarthroplasties had contact areas ranging from 40–70% that of the native articulation (p=0.1). The two capitellar implants had similar contact areas at all flexion angles tested (p>0.05). The contact shape of the native radiocapitellar articulation was ellipsoid, with a range of circularity values from 0.530.19 to 0.720.16, depending on the flexion and rotation angle. At 0 and 90 flexion, there was no difference in contact shape between the native articulation, the anatomical, or spherical implant (p>0.05). At 45 flexion, the anatomical implant contact was less circular than either the native articulation (p=0.006) or the spherical hemiarthroplasty (p=0.002). Conclusion. Metallic capitellar hemiarthroplasty causes a significant reduction in contact area at 0 and 45 elbow flexion, which may have important long-term implications for wear of the radial head cartilage. This reduction is similar to previous reports, which have evaluated the effect of metallic radial head hemiarthroplasty articulating with the native capitellum. More compliant alternative materials are needed to improve the contact characteristics of metallic capitellar hemiarthroplasties. Although the anatomical hemiarthroplasty was created from a detailed morphological study of the capitellum, the anatomical implant failed to completely reproduce the contact native shape. The theoretical advantages of a more anatomical capitellar implant shape may not be realized clinically, suggesting a spherical implant, which is easier to manufacture and implant, may be adequate for patient application. Further studies are required to delineate the effect of this altered contact morphology on implant function and radial head wear in-vivo

Implant choice was changed from cemented Thompson to Exeter Trauma Stem (ETS) for treatment of displaced intra-capsular neck of femur fractures in University Hospital Aintree, Liverpool, United Kingdom (a major trauma center), following the NICE guidelines that advised about the use of a proven femoral stem design rather than Austin Moore or Thompson stems for hemiarthroplasties. The aim of our study was to compare the results of Thompson versus ETS hemiarthroplasty in Aintree. We initially compared 100 Thompson hemiarthroplasties that were performed before the start of ETS use, with 100 ETS hemiarthroplasties. There was no statistically significant difference between the two groups in terms of patients' demographics (age, sex and ASA grade), intra-operative difficulties/complications, post op medical complications, blood transfusion, in-patient stay and dislocations. The operative time was statistically significantly longer in the ETS group (p= .0067). Worryingly, the 30 days mortality in ETS group was more than three times higher in ETS group (5 in Thompson group versus 16 in ETS group. P= .011). To corroborate our above findings we studied 100 more consecutive patients that had ETS hemiarthroplasty. The results of this group showed 30 day mortality of 8 percent. However the operative time was again significantly longer (p= .003) and there was 18 percent conversion to bipolar hemiarthropalsty. Moreover there was statistically significant increased rate of deep infection (7%, p = .03) and blood transfusion (27%, p = .007). This we feel may be due to longer and more surgically demanding operative technique including pressurised cementation in some patients with significant medical comorbidities. Our results raise the question whether ETS hemiarthoplasty implant is a good implant choice for neck of femur fracture patients. Randomised control trials are needed to prove that ETS implant is any better than Thompson hemiarthroplasty implants in this group of patients

Introduction. The hip hemiarthroplasty in posterior approach is a common surgical procedure at the femoral neck fractures in the elderly patients. However, the postoperative hip precautions to avoid the risk of dislocations are impeditive for early recovery after surgery. We used MIS posterior approach lately known as conjoined tendon preserving posterior (CPP) approach, considering its enhancement of joint stability, and examined the intraoperative and postoperative complications, retrospectively. Methods. We performed hip hemiarthroplasty using CPP approach in 30 patients, and hip hemiarthroplasty using conventional posterior approach in 30 patients, and both group using lateral position with the conventional posterior skin incision. The conjoined tendon (periformis, obturator internus, and superior/inferior gemellus tendon) was preserved and the obturator externus tendon was incised in CPP approach without any hip precautions postoperatively. The conjoined tendon was incised in conventional approach using hip abduction pillow postoperatively. Results. There was no difference between CPP approach group and conventional approach group in the mean age of patients (81.8 years, and 80.3 years, respectively), and in the mean operative time (68.8 minutes, and 64.9 minutes, respectively). In 4 cases of CPP approach, the avulsion fracture at femoral attachment of the conjoined tendon occured during hip reduction manoeuvres. No dislocations occured in both groups in the follow-up period (2 years). Discussion. Lately, the number of hip surgery in muscle sparing approach is increasing. However, in general, MIS approach induces the intraoperative complications, and requires the skillful procedure. The hip reduction manoeuvres would be more difficult in the CPP approach, than in conventional posterior approach, because the preserved conjoined tendon would inhibit hip reduction, considering those avulsion fractures of the femoral attachment. Nevertheless, CPP approach did not require no extended time compared to conventional approach, and no postoperative hip precautions. Due to these results, CPP approach could be a good MIS procedure including early recovery after surgery based on the enhancement of joint stability, excluding the difficulties in hip reduction manoeuvres. We could not show the difference in dislocation rate between two groups, because of small numbers. We are planning to increase the number of patients in the future study

Worldwide, it is expected that 6.3 million patients will sustain a hip fracture in 2050. Hemiarthroplasty is commonly practiced for displaced femoral neck fractures. The choice between unipolar (UH) or bipolar (BH) hemiarthroplasty is still controversial. The objective of this study was to assess the effect on hip function of BH compared to UH for a displaced femoral neck fracture in elderly patients. We conducted a systematic review and meta-analysis of randomized controlled trials comparing BH to UH. Data sources were Medline, Embase, Cochrane Library and Web of Science. All data was pooled in Review Manager (RevMan) version 5.3 software. Selection of the studies included, data abstraction, data synthesis, risk of biais and quality of evidence evaluation was done independently by two authors. Our primary outcome was postoperative hip function. Secondary outcomes were health-related quality of life (HRQoL), acetabular erosion and postoperative complications. 13 randomized controlled trials (n=2256) were eligible for the meta-analysis. There was no difference in hip function scores (standardized mean difference of 0.33 [−0.09–0.75, n=864, I. 2. = 87%,]). Patients with bipolar heads had higher Health-Related Quality of Life scores than patients with unipolar heads (mean difference in EQ-5D scores of 0.12 [0.04–0.19, n=550, I. 2. = 44%]). The use of BH decreased the incidence of acetabular erosion (relative risk of 0.37 [0.17–0.83, n=525, I. 2. = 0%]). There was no relative risk difference for mortality, dislocation, revision and infection. Due to the high heterogeneity between the studies included, it is still unclear whether patients undergoing BH have better hip function than patients undergoing UH. Although, health-related quality of life (HRQoL) may be improved. Future research could be conducted to determine whether a BH offers a better quality of life than UH to geriatric patients undergoing surgery. More precise assessment scores could be developed to better evaluate postoperative outcomes

Aim. The aim of this investigation was to compare risk of infection in both cemented and cementless hemiarthroplasty (HA) as well as total hip arthroplasty (THA) following femoral neck fracture. Methods. Data collection was performed using the German Arthroplasty Registry (EPRD) In HA and THA following femoral neck fracture fixation method was divided into cemented and cementless protheses and paired according to age, sex, body mass index (BMI), and the Elixhauser score using Mahalanobis distance matching. Results. Overall in 13,612 cases of intracapsular femoral neck fracture, with 9,110 (66.9 %) HAs and 4502 (33.1 %) THAs were analyzed. Infection rate in HA was significantly reduced in cases with use of antibiotic-loaded cement compared to cementless fixated prosthesis (p=0.013). In patients with THA no statistical difference between cemented and cementless prothesis was registered, however after one year 2.4 % of infections were detected in cementless and 2.1 % in cemented THA. In the subpopulation of HA after one year 1.9 % of infections were registered in cemented and 2.8 % in cementless HA. BMI (p=0.001) and Elixhauser-Comorbidity-Score (p<0.003) were identified as risk factors of PJI, while in THA also cemented prosthesis demonstrated within the first 30 days an increased risk (HR=2.728; p=0.010). Conclusion. The rate of infection after intracapsular femoral neck fracture was significantly reduced in patients treated by antibiotic-loaded cemented hemiarthroplasty. In particular for patients with multiple risk factors for the development of a PJI the usage of antibiotic-loaded bone cement seems to be a reasonable procedure for prevention of infection

Purpose:. Tuberosity healing in hemiarthroplasty for proximal humerus fractures remains problematic. Improved implant design and better techniques for tuberosity fixation have not been met with improved clinical results. The etiology for tuberosity failure is multifactorial; however thermal injury to host bone is a known effect of using polymethylmethacrylate for implant fixation. We hypothesized that the effect of thermal injury at the tuberosity shaft junction could be diminished by utilizing an impaction grafting technique for hemiarthroplasty stems. Methods:. Five matched pairs of cadaveric humeri were skeletonized and hemiarthroplasty stems were implanted in the proximal humeri in two groups. The first group had full cementation utilized from the surgical neck to 2 cm distal to the stem (cement group) and the second group had distal cementation with autologous cancellous bone graft impacted in the proximal 2.5 cm of the stem (impaction grafting group). Thermocouples were used to measure the inner cortical temperature at the tip of the stem, surgical neck, and at the level of the cement-graft interface for both treatment groups (see Fig. 1). Experiments were initiated with the humeri fully submerged in 0.9% sodium chloride and all three thermocouples registering a temperature of 37 ± 1°C. Statistical analyses were performed with a one-sided, paired t-test. Results:. The maximum recorded cortical bone temperature at the surgical neck was significantly decreased by 23% from 52.4 ± 8.1°C in the cement group to 40.4 ± 4.8°C in the impaction grafting group (p = 0.037). We identified no significant differences in maximum recorded temperature at the cement-graft interface between the impaction grafting group (44.3 ± 6.3°C) and the cement group (47.4 ± 6.4°C) (p = 0.254). A similar finding was observed between groups at the tip of the hemiarthroplasty stem (impaction grafting group 54.2 ± 5.7°C; cemented group 52.3 ± 7.3°C, p = 0.303). Conclusion:. Given the known threshold of 47°C as the onset of permanent thermal injury to bone,. 1. impaction grafting maintains the temperature at the surgical neck during cementation below this critical value. Impaction grafting may serve as a beneficial surgical technique to mitigate the effects of thermal injury on tuberosity healing in proximal humeral hemiarthroplasty for fracture

Introduction. Proximal humeral fracture occurs most frequently in elderly and usually unite within 12 weeks. Malunion is more common than nonunion. And even if nonunion occurs, we usually treat it by the blade plate. Norris et al. reported hemiarthroplasty is indicated for severe degenerative changes of the articular surface, osteonecrosis of the humeral head, or osteopenia severe enough to jeopardize fixation in order patients. Therefore, it is not common that hemiarthroplasty is used for primary treatment of the proximal humeral pseudoarthrosis. We report a case of proximal humerus pseudoarthrosis which was treated by hemiarthroplasty. Case. A patients is 75 years old male. He was injured by falling from ladder. He was diagnosed proximal humeral fracture Neer type2. After he was followed conservatively for one year, he was referred to our hospital. In X-ray film and CT, the humeral head was scraped by the humeral shaft that was tucked inward to humeral head.(Figure 1) In MRI, rotator cuff muscles were left. The fatty infiltration was stage 1 in the Gourtallier classification. (Figure 2)And osteoarthritis of shoulder was not so severe. Therefore, we decided to do hemiarthroplasty. We used the SMR implant (Lima Corporate, Milano, Italy). Surgical reconstruction was done using a deltpectral approach. Lesser tuberosity was cut from greater tuberosity with subscaplaris muscle. We used the cementless stem. Each fragments and stem was fixed using FiberWire (Arthrex, Florida USA), after autograft which scraped from the reseceted humeral head was stuffed. After the operation, the shoulder was fixed by brace for 4weeks. The passive ROM exercise was started from 21 days later. The Active ROM exercise was started at 28 days later. Three months later, the pseudoarthrosis united successfully. (Figure 3) The active flexion was improved from 20 degrees to 110 degrees. The active abduction was from 20 degrees to 90 degrees. USLA score was improved from 10 to 26. Discussion. In this case, the pseudoarthrosis is united successfully. Therefore, the cementless hemiarthroplasty is useful for treatment for the proximal humerus pseudoarthrosis with severe humeral head bone defect