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.

Displaced femoral neck fractures can have devastating impacts on quality of life and patient function. Evidence for optimal surgical approach is far from definitive. The Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemi-Arthroplasty (HEALTH) trial aimed to evaluate unplanned secondary procedures following total hip arthroplasty (THA) versus hemi-arthroplasty (HA) within two years of initial surgery for displaced femoral neck fractures. Secondary objectives evaluated differences in patient function, health-related quality of life, mortality, and hip-related complications HEALTH is a large randomized controlled trial that included 1,495 patients across 81 centers in 10 countries. Patients aged 50 years or older with displaced femoral neck fractures received either THA or HA. Participants were followed for 24 months post-fracture and a Central Adjudication Committee adjudicated fracture eligibility, technical placement of prosthesis, additional surgical procedures, hip-related complications, and mortality. The primary analyses were a Cox proportional hazards model with time to the primary study endpoint as the outcome and THA versus HA as the independent variable. Using multi-level linear models with three levels (centre, patient, and time), with patient and centre entered as random effects, the effect of THA versus HA on quality of life (Short Form-12 (SF-12) and EQ-5D), function (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)), and mobility (Timed Up and Go Test (TUG)) were estimated separately.

The majority of patients were female (70.1%), 70 years of age or older (80.2%), and able to ambulate without the aid of an assistive device before their fracture (74.4%), and the injury in the majority of the patients was a subcapital femoral neck fracture (61.9%). The primary end point occurred in 57 of 718 patients (7.9%) who were randomly assigned to THA and 60 of 723 patients (8.3%) who were randomly assigned to HA (hazard ratio, 0.95; 95% confidence interval [CI], 0.64 to 1.40; p=0.79). Hip instability or dislocation occurred in 34 patients (4.7%) assigned to total hip arthroplasty and 17 patients (2.4%) assigned to hemi- arthroplasty (hazard ratio, 2.00; 99% CI, 0.97 to 4.09). Function, as measured with the total WOMAC total score, pain score, stiffness score, and function score, modestly favored THA over HA. Mortality was similar in the two treatment groups (14.3% among the patients assigned to THA and 13.1% among those assigned to HA, p=0.48). Serious adverse events occurred in 300 patients (41.8%) assigned to THA and in 265 patients (36.7%) assigned to HA.

Among independently ambulating patients with displaced femoral neck fractures, the incidence of secondary procedures did not differ significantly between patients who were randomly assigned to undergo THA and those who were assigned to undergo HA, and THA provided a clinically unimportant improvement over HA in function and quality of life over 24 months.

The surgical treatment options for patients who have sustained an intra-capsular hip fracture can vary depending on a number of patient and fracture related factors. Currently most national guidelines support the use of cemented prostheses for patient undergoing hemiarthroplasty surgery. Uncemented prostheses are commonly used for a variety of indications including those patients who have significant medical co-morbidities.

To determine whether cemented hemiarthroplasty is associated with a higher post operative mortality when compared to uncemented procedures. Data were extracted from the Scottish SMR01 database from 01/04/1997 from all patients who were admitted to hospital after sustaining a hip fracture. We investigated mortality at day 1,2,4,7,30, 120 and 1 year from surgery vs. that on day 0. In order to control for the effects of confounding variables between patients cohorts, 12 case-mix variable were used to construct a multivariable logistic regression analysis model to determine the independent effect of prosthesis design.

There were 52283 patients included in the study. Mortality for osteosynthesis of extra-capsular fractures was consistently lower when compared to that for surgical procedures for intra-capsular fractures. At day 0, uncemented hemiarthroplasty had a lower associated mortality (p<0.001) when compared to cemented implant designs. However, this increased mortality was equal to 1 extra death per 2000 procedures. From day 1 onward mortality for cemented procedures was equal to or lower than that of uncemented. By day 4, cumulative mortality was less for cemented than for uncemented procedures. Complication and re-operation rate was significantly higher in the uncemented cohort.

The use of uncemented hemiarthroplasty for the treatment of intra-capsular hip fractures cannot be justified in terms of early/late post-operative mortality.

The surgical treatment options for patients who have sustained an intra-capsular hip fracture can vary depending on a number of patient and fracture related factors. Currently most national guidelines support the use of cemented prostheses for patient undergoing hemi-arthroplasty surgery. Uncemented prostheses are commonly used for a variety of indications including those patients who have significant medical co-morbidities.

To determine whether cemented hemi-arthroplasty is associated with a higher post operative mortality when compared to uncemented procedures. Data was extracted from the Scottish SMR01 database from 01/04/1997 from all patients who were admitted to hospital after sustaining a hip fracture. We investigated mortality at day 1, 2, 4, 7, 30, 120 and 1 year from surgery vs. that on day 0. In order to control for the effects of confounding variables between patients cohorts, 12 case-mix variable were used to construct a multivariable logistic regression analysis model to determine the independent effect of prosthesis fixation method.

There were 64,979 patients were included in the study. Mortality for osteosynthesis of extra-capsular fractures was consistently lower when compared to that for surgical procedures for intra-capsular fractures. At day 0, uncemented hemi-arthroplasty operations had a lower associated mortality (p<0.001) when compared to cemented implant designs. Unadjusted figures showed an increased mortality equal to 1 extra death per 424 procedures. By day 1 this had become 1 extra death per 338 procedures. By day 7 cumulative mortality was less for cemented than for uncemented procedures though this did not reach significance until day 120.

When compared to uncemented fixation techniques, cemented hemiarthroplasty is associated with a higher mortality in the immediate postoperative period. However, by day 120 and beyond the trend is reversed.

To determine if any notable differences between a cemented Thompson stem hemiarthroplasty and a cemented Exeter stem hemiarthroplasty (ETS), 200 patients with a displaced intracapsular fracture were randomised between the two prosthesis. Surviving patients were followed-up for one year by a nurse blinded to the treatment allocation. The mean age of patients was 84 years and 13% were male.

There were no differences between groups for the length of surgery, need for blood transfusion or hospital stay. Implant related complications were three minor operative fractures of the femur in each group. Two patients in the Thompson group had dislocation of the prosthesis requiring revision surgery and one further patient in the Thompson group had late acetabular wear requiring conversion to a total hip replacement. One further patient in the Thompson group had cement retained in the acetabulum. In total therefore only three patients, all in the Thompson group, which required revision surgery. Easy of surgery was assessed subjectively by the surgeon and reported to be easier for the ETS group (p=0.0002). During follow-up there was no significant difference in the degree of residual pain between groups.

Conclusions are that the cemented Exeter stem hemiarthroplasty has some advantages over the traditional cemented Thompson hemiarthroplasty.

Introduction

Following National patient safety alert on cement use in hip fracture surgery, we investigated the incidence and pattern of 72 hours peri-operative mortality after hip fracture surgery in a District General Hospital.

We report the results of a consecutive series of 500 patients treated with a follow-up range from 5–12 years.

Ten patients were lost to follow-up and 398 patients [81%] died. The mean age was 82 years, with 85% being women. Forty-six patients [9.2%] required a second operation of any type, with revision performed in 23 [4.6%]. Of the long-term survivors 66 [81%] had none or minimal pain, whilst 5 [6%] had reported constant pain in the hip.

This is the largest consecutive series, with the following follow-up, reported and for the frail elderly patient this prosthesis can still be recommended.

Introduction

In comminuted intertrochanteric fractures, various operative options have been introduced. The purpose of this study was to determine whether there were differences in clinical and radiologic outcomes among bipolar hemiarthroplasty(BH), compression hip screw(CHS) and proximal femur nail antirotatory(PFNA) in treating comminuted intertrochanteric fractures(AO type, A2(21, 22, 23))

Hip precautions are currently practiced in three-quarters of trauma hospitals in the UK, despite national recommendations from the ‘Blue Book’ not stating it as a requirement. Valuable therapist time is utilised alongside the need for specialised equipment, which can potentially delay discharge whilst it is being arranged. Objective of this study was to explore the current practice of the use of hip precautions on discharge following hemiarthroplasty for hip fractures. To also explore whether they are necessary and to identify areas for improvement to benefit patient care overall. Online survey distributed to various Trauma and Orthopaedic Departments across the UK. Survey was available over a 4-month period, collecting 55 responses overall. Majority of responses were from trauma and orthopaedic consultants who were aware of the ‘Blue Book’ recommendations. The majority of trusts who responded did not practice hip precautions and did not feel this increased the risk of dislocations on discharge. Recommendations included integration of hip precautions in the post-op advice in coordination with the physiotherapist and information leaflets on discharge regarding hip precautions. Hip precautions were not commonly practiced, for reasons including patient compliance and the inherently stable procedure of a hemiarthroplasty compared to a THR, reducing the need for hip precautions. Hip precautions are not widely regarded as a useful practice for post-hip hemiarthroplasty, viewed as utilising more resources and increasing costs and risk due to increased hospital stay. Thus, this potentially delays discharge overall. A consistent approach should be implemented in treating patients post-hip hemiarthroplasty

Aims. To evaluate if, for orthopaedic trainees, additional cadaveric simulation training or standard training alone yields superior radiological and clinical outcomes in patients undergoing dynamic hip screw (DHS) fixation or hemiarthroplasty for hip fracture. Methods. This was a preliminary, pragmatic, multicentre, parallel group randomized controlled trial in nine secondary and tertiary NHS hospitals in England. Researchers were blinded to group allocation. Overall, 40 trainees in the West Midlands were eligible: 33 agreed to take part and were randomized, five withdrew after randomization, 13 were allocated cadaveric training, and 15 were allocated standard training. The intervention was an additional two-day cadaveric simulation course. The control group received standard on-the-job training. Primary outcome was implant position on the postoperative radiograph: tip-apex distance (mm) (DHS) and leg length discrepancy (mm) (hemiarthroplasty). Secondary clinical outcomes were procedure time, length of hospital stay, acute postoperative complication rate, and 12-month mortality. Procedure-specific secondary outcomes were intraoperative radiation dose (for DHS) and postoperative blood transfusion requirement (hemiarthroplasty). Results. Eight female (29%) and 20 male trainees (71%), mean age 29.4 years, performed 317 DHS operations and 243 hemiarthroplasties during ten months of follow-up. Primary analysis was a random effect model with surgeon-level fixed effects of patient condition, patient age, and surgeon experience, with a random intercept for surgeon. Under the intention-to-treat principle, for hemiarthroplasty there was better implant position in favour of cadaveric training, measured by leg length discrepancy ≤ 10 mm (odds ratio (OR) 4.08 (95% confidence interval (CI) 1.17 to 14.22); p = 0.027). There were significantly fewer postoperative blood transfusions required in patients undergoing hemiarthroplasty by cadaveric-trained compared to standard-trained surgeons (OR 6.00 (95% CI 1.83 to 19.69); p = 0.003). For DHS, there was no significant between-group difference in implant position as measured by tip-apex distance ≤ 25 mm (OR 6.47 (95% CI 0.97 to 43.05); p = 0.053). No between-group differences were observed for any secondary clinical outcomes. Conclusion. Trainees randomized to additional cadaveric training performed hip fracture fixation with better implant positioning and fewer postoperative blood transfusions in hemiarthroplasty. This effect, which was previously unknown, may be a consequence of the intervention. Further study is required. Cite this article: Bone Jt Open 2023;4(8):602–611

Recent registry data from around the world has strongly suggested that using cemented hip hemiarthroplasty has lower revision rates compared to cementless hip hemiarthroplasty for acute femoral neck hip fractures. The adoption of using cemented hemiarthroplasty for hip fracture has been slow as many surgeons continue to use uncemented stems. One of the reasons is that surgeons feel more comfortable with uncemented hemiarthroplasty as they have used it routinely. The purpose of this study is to compare the difference in revision rates of cemented and cementless hemiarthroplasty and stratify the risk by surgeon experience. By using a surgeons annual volume of Total Hip Replacements performed as an indicator for surgeon experience. The Canadian Joint Replacement Registry Database was used to collect and compare the outcomes to report on the revision rates based on surgeon volume. This is a large Canadian Registry Study where 68447 patients were identified for having a hip hemiarthroplasty from 2012-2020. This is a retrospective cohort study, identifying patients that had cementless or cemented hip hemiarthroplasty. The surgeons who performed the procedures were linked to the procedure Total Hip Replacement. Individuals were categorized as experienced hip surgeons or not based on whether they performed 50 hip replacements a year. Identifying high volume surgeon (>50 cases/year) and low volume (<50 cases/year) surgeons. Hazard ratios adjusted for age and sex were performed for risk of revision over this 8-year span. A p-value <0.05 was deemed significant. For high volume surgeons, cementless fixation had a higher revision risk than cemented fixation, HR 1.29 (1.05-1.56), p=0.017. This pattern was similar for low volume surgeons, with cementless fixation having a higher revision risk than cemented fixation, HR 1.37 (1.11-1.70) p=0.004 We could not detect a difference in revision risk for cemented fixation between low volume and high volume surgeons; at 0-1.5 years the HR was 0.96 (0.72-1.28) p=0.786, and at 1.5+ years the HR was 1.61 (0.83-3.11) p=0.159. Similarly, we could not detect a difference in revision risk for cementless fixation between low volume and high volume surgeons, HR 1.11 (0.96-1.29) p=0.161. Using large registry data, cemented hip hemiarthroplasty has a significant lower revision rate than the use of cementless stems even when surgeons are stratified to high and low volume. Low volume surgeons who use uncemented prostheses have the highest rate of revision. The low volume hip surgeon who cements has a lower revision rate than the high volume cementless surgeon. The results of this study should help to guide surgeons that no matter the level of experience, using a cemented hip hemiarthroplasty for acute femoral neck fracture is the safest option. That high volume surgeons who perform cementless hemiarthroplasty are not immune to having revisions due to their technique. Increased training and education should be offered to surgeons to improve comfort when using this technique

Recent registry data from around the world has strongly suggested that using cemented hip hemiarthroplasty has lower revision rates compared to cementless hip hemiarthroplasty for acute femoral neck hip fractures. The adoption of using cemented hemiarthroplasty for hip fracture has been slow as many surgeons continue to use uncemented stems. One of the reasons is that surgeons feel more comfortable with uncemented hemiarthroplasty as they have used it routinely. The purpose of this study is to compare the difference in revision rates of cemented and cementless hemiarthroplasty and stratify the risk by surgeon experience. By using a surgeons annual volume of Total Hip Replacements performed as an indicator for surgeon experience. The Canadian Joint Replacement Registry Database was used to collect and compare the outcomes to report on the revision rates based on surgeon volume. This is a large Canadian Registry Study where 68447 patients were identified for having a hip hemiarthroplasty from 2012-2020. This is a retrospective cohort study, identifying patients that had cementless or cemented hip hemiarthroplasty. The surgeons who performed the procedures were linked to the procedure Total Hip Replacement. Individuals were categorized as experienced hip surgeons or not based on whether they performed 50 hip replacements a year. Identifying high volume surgeon (>50 cases/year) and low volume (<50 cases/year) surgeons. Hazard ratios adjusted for age and sex were performed for risk of revision over this 8-year span. A p-value <0.05 was deemed significant. For high volume surgeons, cementless fixation had a higher revision risk than cemented fixation, HR 1.29 (1.05-1.56), p=0.017. This pattern was similar for low volume surgeons, with cementless fixation having a higher revision risk than cemented fixation, HR 1.37 (1.11-1.70) p=0.004 We could not detect a difference in revision risk for cemented fixation between low volume and high volume surgeons; at 0-1.5 years the HR was 0.96 (0.72-1.28) p=0.786, and at 1.5+ years the HR was 1.61 (0.83-3.11) p=0.159. Similarly, we could not detect a difference in revision risk for cementless fixation between low volume and high volume surgeons, HR 1.11 (0.96-1.29) p=0.161. Using large registry data, cemented hip hemiarthroplasty has a significant lower revision rate than the use of cementless stems even when surgeons are stratified to high and low volume. Low volume surgeons who use uncemented prostheses have the highest rate of revision. The low volume hip surgeon who cements has a lower revision rate than the high volume cementless surgeon. The results of this study should help to guide surgeons that no matter the level of experience, using a cemented hip hemiarthroplasty for acute femoral neck fracture is the safest option. That high volume surgeons who perform cementless hemiarthroplasty are not immune to having revisions due to their technique. Increased training and education should be offered to surgeons to improve comfort when using this technique

Aims. Patients receiving cemented hemiarthroplasties after hip fracture have a significant risk of deep surgical site infection (SSI). Standard UK practice to minimize the risk of SSI includes the use of antibiotic-loaded bone cement with no consensus regarding type, dose, or antibiotic content of the cement. This is the protocol for a randomized clinical trial to investigate the clinical and cost-effectiveness of high dose dual antibiotic-loaded cement in comparison to low dose single antibiotic-loaded cement in patients 60 years and over receiving a cemented hemiarthroplasty for an intracapsular hip fracture. Methods. The WHiTE 8 Copal Or Palacos Antibiotic Loaded bone cement trial (WHiTE 8 COPAL) is a multicentre, multi-surgeon, parallel, two-arm, randomized clinical trial. The pragmatic study will be embedded in the World Hip Trauma Evaluation (WHiTE) (ISRCTN 63982700). Participants, including those that lack capacity, will be allocated on a 1:1 basis stratified by recruitment centre to either a low dose single antibiotic-loaded bone cement or a high dose dual antibiotic-loaded bone cement. The primary analysis will compare the differences in deep SSI rate as defined by the Centers for Disease Control and Prevention within 90 days of surgery via medical record review and patient self-reported questionnaires. Secondary outcomes include UK Core Outcome Set for hip fractures, complications, rate of antibiotic prescription, resistance patterns of deep SSI, and resource use (more specifically, cost-effectiveness) up to four months post-randomization. A minimum of 4,920 patients will be recruited to obtain 90% power to detect an absolute difference of 1.5% in the rate of deep SSI at 90 days for the expected 3% deep SSI rate in the control group. Conclusion. The results of this trial will provide evidence regarding clinical and cost-effectiveness between low dose single and high dose dual antibiotic-loaded bone cement, which will inform policy and practice guidelines such as the National Institute for Health and Care Excellence guidance on management of hip fractures. Cite this article: Bone Jt Open 2021;2(2):72–78

Abstract. Objectives. The development of promising therapeutics for cartilage repair/regeneration have been hampered by the inadequacy of existing animal models and lack of suitable translational ex-vivo human tissue models. There is an urgent unmet need for these to assess repair/regenerative (orthobiologic) treatments directly in human tissue. We describe methodology allowing the successful long-term ex-vivo culture of non-degenerate whole human femoral heads that may be used as a model for testing new orthobiologic therapies. Methods. Fifteen fresh, viable human femoral heads were obtained from 15 patients (with ethical permission/consent) undergoing hemiarthroplasty for hip fracture, and cultured aseptically (37°C) for up to 10wks. Culture conditions included static/stirred standard media (Dulbecco's modified Eagle's medium; DMEM) and supplementation with 10% human serum (HS). Chondrocyte viability, density, cell morphology, cell volume, glycosaminoglycan(GAG)/collagen content, surface roughness and cartilage thickness were quantified over time. Results. Chondrocyte viability remained highest (>95%;P<0.01;N(n)=3(12)) under static culture conditons in DMEM+10%HS and was maintained over 10wks. In static DMEM culture without 10%HS, viability remained high for ∼4wks, then decreased rapidly (N(n)=4(16)). Chondrocyte viability declined to <35% over 10wks under all other conditions (N(n)=4(16)). Culturing femoral heads in optimal media (DMEM+10%HS) for 10wks increased the number of chondrocytes producing cytoplasmic processes (P<0.002), but decreased cartilage thickness (P<0.002) and GAG content (P=0.028). Cartilage surface roughness, cellular density, chondrocyte volume and collagen content remained unchanged (P>0.05). Conclusions. The viability of human femoral head articular cartilage could be maintained over 10wks in ex-vivo culture. The model may allow testing of a wide range of orthobiologic therapies directly in human tissue, paving the way for subsequent targeted clinical studies of laboratory-proven strategies with the potential to repair/regenerate articular cartilage. Funder. Chief Scientist's Office, Scotland (Grant TCS/18/01). Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Aims

This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures.

Aims

Cementing in arthroplasty for hip fracture is associated with improved postoperative function, but may have an increased risk of early mortality compared to uncemented fixation. Quantifying this mortality risk is important in providing safe patient care. This study investigated the association between cement use in arthroplasty and mortality at 30 days and one year in patients aged 50 years and over with hip fracture.

Revision is a key negative outcome of joint replacements. The purpose of this abstract is to present revision risk curves for hip and knee replacements based on the most recently available national data sources. Having a better understanding of determinants of revision risk can help inform clinical and health care system improvements. We explored revision risk of primary joint replacement stratified by key clinical, prosthesis, and surgeon-level factors using data from three databases managed by CIHI: the Canadian Joint Replacement Registry (CJRR), the Discharge Abstract Database, and the National Ambulatory Care Reporting System. To investigate early revisions, we used Kaplan-Meier analysis stratified by demographic factors to determine the risk of revision within up to five years of primary surgery. This analysis identified the primary cohort from the CJRR from April 1, 2012 to March 31, 2017 and was limited to mandatory reporting provinces (British Columbia, Manitoba and Ontario) to ensure maximal coverage of prosthesis information. Bearing surface was obtained from the International Prosthesis Library maintained by the International Consortium of Orthopaedic Registries (ICOR) and the International Society of Arthroplasty Registers (ISAR). The total revision risk cohort contained 283,620 primary surgeries, of which 5,765 (2%) had at least one revision. For total hip arthroplasties, revision risk at the end of the follow-up period did not differ by age, by sex or across bearing surface (metal on cross-linked polyethylene [XLPE], ceramic on XLPE, ceramic on ceramic, metal on non-cross-linked polyethylene). For hemiarthroplasties in hip fracture patients, cement fixation was significantly associated with decreased revision risk. Surgeon volume had a positive effect on survivorship with cementless fixation (2.7% at one year [95% CI 2.3%, 3.1%] for high-volume vs 3.2% [2.7%, 3.7%] for low-volume). However, surgeon volume did not have an effect on survivorship with cemented fixation (2% at one year [95% CI 1.3%, 2.6%] for high-volume vs. 2% [1.4%, 2.6%] for low-volume). For total knee replacements, revision risk increased with decreasing age and male sex. For patients aged 75 and older, four-year revision risks were 1.5% (95% CI 1.3%, 1.7%) for women and 2.0% (1.7%, 2.3%) for men, but for patients under 55 years old, they were 4.3% (3.7%, 5%) for women and 5.9% (4.9%, 6.9%) for men. Additional results from the upcoming 2019 CJRR annual report, including data up to March 31, 2018, will be presented. Revisions represent a key failure of the primary replacement, they are costly to the health care system and negatively affect patients' quality of life. CJRR's coverage is currently 72%, increased coverage and follow-up time will allow increasingly comprehensive reporting on hip and knee prostheses in Canada. Future work in this area involves exploring additional prosthesis attributes for stratification of revision risk curves and calculation of hazards ratios adjusted by age and sex

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

To examine surgeon supervision in orthopaedic trauma in Australia. An Australia-wide cross-sectional survey was performed using a mass electronic mail-out distributed to members of the Australian Orthopaedic Association. Rates of supervision for six common operations (tibial nailing, femoral nailing, hip hemiarthroplasty, hip fracture fixation, ankle fracture fixation, paediatric supracondylar fracture). Other factors recorded included; payment type, hospital type, state, seniority, theatre availability, and trauma load. Responses were tabulated and analysed using SAS software. 21.9% of surgeons completed the survey, out of 739 surgeons who were sent the e-mail invitation. Univariate analysis showed increased supervision to be associated with; more junior consultants, regional and rural hospitals, state (NSW and Victoria), and method of payment (fee for service). However, multivariate analysis showed that fee for service payment (compared to sessional payment) was the only factor significantly associated with increased supervision for all operations surveyed. Higher remuneration for surgeons may increase supervision rates of trainees

Aims

The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells.