Introduction: Although THR can provide excellent pain relief and restore functional ability for most patients, there is a proportion of patients who experience a poor functional outcome after THR. One factor that could contribute to a poor outcome after THR is leg length discrepancy (LLD). Restoration of leg length is important in optimising hip biomechanics and LLD has several consequences for the patient, including back pain and a limp. Assessment of LLD using radiographs is time consuming and labour intensive, and therefore limits large scale studies of LLD. However, patients self-report of perceived LLD may be a useful tool to study LLD on a large scale. Therefore, the aim of this postal audit survey was to determine the prevalence of patient-perceived LLD after primary THR and its impact on mid-term functional outcomes. Methods: A cross-sectional postal audit survey of all consecutive patients who had a primary, unilateral THR at the Avon Orthopaedic Centre 5–8 years previously was conducted. Several questions about LLD were included on the questionnaire. Firstly, patients were asked if they thought that their legs were the same length. For those who thought their legs were different lengths, they were asked if the difference bothered them, whether the difference in length leg was enough to comment upon, and whether they used a shoe raise. Participants also completed an Oxford hip score (OHS), which is a self-report measure that assesses functional ability and pain after THR, including limping. Results: 1,114 THR patients returned a completed questionnaire, giving a response rate of 73%. 329 patients (30%) reported that they thought their legs were different lengths. The median OHS for patients with a perceived LLD was 22, which was significantly worse than the OHS of 18 for patients who thought their legs were the same length (p< 0.001). Of the 329 patients with a perceived LLD, 161 patients (51%) were bothered by the difference, 65 patients (20%) thought the discrepancy was sufficient to comment upon and 101 patients (31%) used a shoe raise. 31% of patients with LLD limped most or all of the time compared to only 9% of patients without LLD. Conclusion: In conclusion, this study found that the prevalence of perceived LLD at 5–8 years after THR was 30%. Of the patients with LLD, over 50% were bothered by the LLD and over a third used a shoe raise to equalise leg lengths. Patients with perceived LLD have a significantly poorer self-report functional outcome than those patients without LLD. It is therefore important that patients are informed pre-operatively of the high risk of LLD after THR and the associated negative impact this may have on their outcome

Introduction. Corrosion products from modular taper junctions of hip prostheses have been implicated in adverse local tissue reactions after THR. Numerous factors have been proposed as the root causes of this phenomenon, including implant design and materials, manufacturing variables, intraoperative assembly, and patient lifestyle. As significant taper damage only occurs in a few percent of cases of THR, we have addressed this complication using a “forensic” examination of retrieval specimens to gain insight into the factors initiating the cascade leading to irreversible damage of the modular interface. In this study we report the categorization of over 380 retrievals into groups having shared damage patterns, metallic composition, and interface surface geometries to isolate the genesis of mechanically-assisted corrosion and its relation to intraoperative assembly, manufacturing, and postoperative loading. Methods. A total of 384 femoral components were examined after retrieval at revision THR. The implants were produced by a diverse range of manufacturers, 271 in CoCr, and 113 in TiAlV, with both smooth (253) and machined (131) tapers. Initially, the implants were sorted into groups based on composition and taper roughness. Each trunnion was then cleaned to remove organic deposits and examined by stereomicroscopy at X6-X31. After an initial pilot study, we developed a classification system consisting of 8 basic patterns of damage (Table 1). We then classified all 384 trunnions according to this 8-group system. The prevalence of each pattern was calculated on the basis of both composition and surface texture of the trunnion. Results. Overall, 81% of the trunnions had visible areas of surface damage, which varied as a function of composition (CoCr: 77%; TiAlV: 90%; p=0.002) and finish (smooth: 88%; machined: 67%; p<0.001). The most common pattern of damage was a circumferential ring at the base of the taper (24%) followed by a group with slight fretting or assembly damage distributed over the entire taper (19%). Damage to one quadrant at the bottom third was seen in approximately 18%. When combining material types, 41% of smooth tapers had circumferential patterns of damage corresponding to groups 2, 3, and 5. Conversely, 77% of the machined tapers had damage limited to one side or on two opposite sides (Patterns 4, 6, 7, 8, and 9). Discussion. Our results show that the pattern and location of damage is influenced not only by composition and surface texture, but can also be an indicator of component fit. The damage patterns observed on almost half (45%) of the trunnions were not circumferential (Chart 2), suggesting that misalignment of the head during assembly may be responsible for initiating the corrosion cascade in stems with machined taper surfaces. Summary. We categorized over 380 implant retrievals into groups having shared damage patterns, metallic composition, and interface surface geometries to isolate the genesis of corrosion

Background. As the number of ceramic THR bearings used worldwide is increasing, the number of implants that experience off-normal working conditions, e.g. edge loading, third bodies in the joint, soft tissues laxity, dislocation/subluxation of the joint, increases too. Under all such conditions the bearing surfaces can be damaged, leading eventually to a limitation of the expected performances of the implant. Methods. We characterised the damage resistance of different bearing surfaces (alumina matrix composite BIOLOXdelta, alpha-alumina BIOLOXforte, zirconia 3Y-TZP, oxidized zirconium alloy Zr-2.5Nb, CoCr-alloy) by scratch tests performed following the European standard EN 1071–3:2005. Also the scratch hardness of same materials has been assessed. Results. The Lc1 value (i.e., the load for the onset of a scratch) measured for BIOLOXdelta is about fivefold the one measured for the oxidized zirconium alloy (OXZr) surface and about tenfold the Lc1 measured for the CoCr alloy. The height of ridges along the scratch edges due to plastic flow in the composite ceramic BIOLOXdelta are only 21% in height than in CoCr, and only a small fraction (0.04%) of the height of ridges measured on OXZr surfaces. The scratch hardness of the metal samples tested (CoCr, OXZr) results one order of magnitude lower than the ones of ceramics. This behavior is not influenced by of the presence of the coating on OXZr surface. Conclusions. The transformation toughened ceramics tested (BIOLOXdelta, 3Y-TZP) are the materials that exhibit the higher resistance to scratching. Ridges at scratch edges are lower in ceramics than in coated or uncoated metals. The result show the superior scratch resistance behavior of toughened ceramics for THR wear couples with respect to coated or bare alloys. Level of Evidence. Level 1

Introduction: Total hip replacement (THR) and total knee replacement (TKR) are widely accepted as effective surgical procedures to alleviate chronic joint pain and improve functional ability. Clinical evidence suggests that joint replacement results in excellent outcomes. Traditionally, reporting of outcomes has been focused on implant survivorship and surgeon based assessment of objective outcomes, such as range of motion, knee stability and radiographic results. However, because there is a discrepancy between patient and clinician ratings of health, patient-reported outcome measures have been validated to allow patients to rate their own health, thereby placing them at the centre of outcome assessment. The aim of this study was to compare the mid-term functional outcomes of TKR and THR using validated patient-reported outcome measures. Methods: A cross-sectional postal audit survey of all consecutive patients who had a primary, unilateral THR or TKR at the Avon Orthopaedic Centre 5–8 years previously was conducted. Participants completed an Oxford hip score (OHS) or Oxford knee score (OKS). The Oxford questionnaires are self-report joint-specific measures that assess functional ability and pain from the patient’s perspective. They consist of 12 questions about pain and physical limitations experienced over the past four weeks because of the hip or knee. Results: 1112 THR patients and 613 TKR patients returned a completed questionnaire, giving a response rate of 72%. The median OKS of 26 was significantly worse than the median OHS of 19 (p< 0.001). TKR patients experienced a poorer functional outcome than THR patients on all domains assessed by the Oxford questionnaire, independent of age. The percentage of patients reporting moderate-severe pain was two-fold greater for TKR than THR patients (26% vs 13%, respectively). Conclusion: This survey found that TKR patients report more pain and functional limitations than THR patients at 5–8 years post-operatively, independent of age. The finding that over a quarter of TKR patients reported moderate-severe pain at 5–8 years post-operative indicates that a large proportion of people are undergoing major knee surgery that is failing to achieve its primary aim of pain relief. This raises questions about whether patient selection for TKR is appropriate. To improve patient selection, it may be necessary to have a preoperative screening protocol to identify patient factors predictive of a poor outcome after TKR. Currently, no such protocol exists and this is an area of orthopaedics requiring further research

The current, most popular recommendation for cup orientation, namely the Lewinnek box, dates back to the 70's, that is to say at the stone age of hip arthroplasty. Although Lewinnek's recommendations have been associated with a reduction of dislocation, some complications, either impingement or edge loading related, have not been eliminated. Early dislocations are becoming very rare and most of them probably occur in “outlier” patients with atypical pelvic/hip kinematics. Because singular problems usually need singular treatments, those patients need a more specific personalised planning of the treatment rather than a basic systematic application of Lewinnek recommendations. We aim in this review to define the potential impacts that the spine-hip relations (SHRs) have on hip arthroplasty. We highlight how recent improvements in hip implants technology and knowledge about SHRs can substantially modify the planning of a THR, and make the «Lewinnek recommendations» not relevant anymore. We propose a new classification of the SHRs with specific treatment recommendations for hip arthroplasty whose goal is to help at establishing a personalized planning of a THR. This new classification (figures 1 and 2) gives a rationale to optimize the short and long-term patient's outcomes by improving stability and reducing edge loading. We believe this new concept could be beneficial for clinical and research purposes

The current, most popular recommendation for cup orientation, namely the Lewinnek box, dates back to the 70's, that is to say at the stone age of hip arthroplasty. Although Lewinnek's recommendations have been associated with a reduction of dislocation, some complications, either impingement or edge loading related, have not been eliminated. Early dislocations are becoming very rare and most of them probably occur in “outlier” patients with atypical pelvic/hip kinematics. Because singular problems usually need singular treatments, those patients need a more specific personalised planning of the treatment rather than a basic systematic application of Lewinnek recommendations. We aim in this review to define the potential impacts that the spine-hip relations (SHRs) have on hip arthroplasty. We highlight how recent improvements in hip implants technology and knowledge about SHRs can substantially modify the planning of a THR, and make the « Lewinnek recommendations » not relevant anymore. We propose a new classification of the SHRs with specific treatment recommendations for hip arthroplasty whose goal is to help at establishing a personalized planning of a THR. This new classification gives a rationale to optimize the short and long-term patient's outcomes by improving stability and reducing edge loading. We believe this new concept could be beneficial for clinical and research purposes

Introduction:. Ankle arthritis is a leading cause of pain and disability. The effect of this condition on physical and mental health is similar to end stage hip arthritis. There is paucity of literature on PROMS following total ankle replacements (TAR) in comparison to total hip replacement (THR) or knee replacement (TKR). We aimed to study 5 year outcomes of TAR in comparison with TKR and THR. Methods:. PROMS data from patients who underwent a primary THR, TKR or TAR from March 2003 to 2013 were collected from our hospital patient registry. They were divided into 3 groups based on the type of primary joint replacement. Patient demographics and patient reported outcomes (WOMAC, SF-36 scores and patient satisfaction scores at follow up) were compared at pre-op and 5 year follow up. Results:. There was data available on 1920 THR, 2582 TKR and 248 TAR patients. Pre-operatively, TAR patients reported higher function scores when compared to THR and TKR (40.2 vs. 34.2 and 35.8; p<0.05). For SF-36 scores, there was no difference between groups for general health, role emotional components (P>0.05); TAR patients reported similar scores to TKRs for physical domains; to THRs for the mental domains (P>0.05). At 5 years post-op, TARs reported lower scores than THRs and TKRs for function and stiffness. For SF-36 scores, TARs reported similar outcomes to THR and TKR for mental health components (p>0.05), similar scores to TKR for 3/4 physical domains (p<0.05), but lower satisfaction rates for ADL and recreation when compared to THR (P<0.05). Conclusion:. TAR patients had similar outcomes to THR or TKR patients for disease specific and mental health domains, and lower patient satisfaction rates in terms of pain relief, ADL and recreation. Further research is warranted including clinical outcomes along with PROMS with a long term follow up

Aims: Elevated serum cobalt and chromium ion levels associated with carcinogenesis and chromosomal damage in animals has raised concerns that metal-on-metal (MOM) total hip replacement (THR) in humans may produce the same effects over time. Considering that the risks may be related to the level of these ions in the body, this study compared the serum cobalt and chromium ion levels in patients with unilateral versus bilateral 28 mm diameter MOM THR. Methods: All patients having THR at our institution were prospectively registered on a computerised database. From our database, we identified 108 patients with Ultima (Johnson and Johnson, Leeds) MOM THR with 28 mm bearing made of cobalt-chromium alloy. After patient review in clinic and before blood results were known, patient matching was performed by date after surgery at blood sampling, activity level and body mass. Using these stringent criteria, 11 unilateral THR could be adequately matched with 11 bilateral THR. Blood serum was taken with full anti-contamination protocols and serum analysed via inductively coupled plasma mass spectrometry. Statistical analysis used the Mann-Whitney U test. Results: The serum cobalt ion level after unilateral MOM THR was 4.4 times normal (median 22 nmol/L, range 15 to 37 nmol/L) compared to 8.4 times normal (median 42 nmol/L, range 19 to 221 nmol/L) for bilateral MOM THR (p=0.001). The serum chromium ion level after unilateral MOM THR was 3.8 times normal (median 19 nmol/L, range 2 to 35 nmol/L) compared to 10.4 times normal (median 52 nmol/L, range 19 to 287 nmol/L) for bilateral MOM THR (p=0.04). Conclusions: This study has shown that the serum cobalt and chromium ion levels in patients with bilateral MOM THR are significantly higher than those in patients with unilateral MOM THR. With levels of up to 50 times the upper limit of normal, this finding may be of relevance for the potential development of long-term side effects

Introduction: Outcome reporting following THR constitute a significant proportion of orthopaedic publications. Publication bias in the form of underreporting of studies showing non satisfactory or negative results is a well recognised problem in other specialities. We tried to find out the magnitude of this problem in orthopaedics publications dealing with THR. Method and materials: We reviewed all publications on THR in the year 2004 in three general orthopaedic journals namely JBJS (BR), JBJS (Am), CORR. Of the 1034 original articles published in these three journals more than 400 articles were concerned with total hip replacement. Results and Discussion: In this study we found only 6% of the published articles were showing non significant or negative results. This raises concerns about evidence based approach in THR and the need for preventive measures like registering all clinical trials and change in the attitude of editorial board

In order to enhance the acceptance of computer assisted surgery in joint replacement, a development-cooperation with BrainLAB, Germany was set up to develop a user-friendly handheld navigation device. A sterile draped Apple® IPod-Touch which is placed into a hardcover cradle, is used as navigation monitor and touchscreen control. Different instruments, such as navigation-pointer are attached to the cradle. In addition the workflows for TKR and THR procedures have been optimised. Therefore the main focus for TKR is navigation of femoral and tibial resection as well as leg alignment control. For the THR the system enables an intraoperative control of leg-length and femoral-offset measurement in comparison with the preoperative situation. Each step of the procedure is supported by video animations of the specific navigation workflow. Between September and December 2010 the first clinical study on the usability in TKR and THR was performed for 20 cases using a prototype system. The study was approved by the local ethic committee and the “German Federal Institute for Drugs and Medical Devices (BfArM)”. Special interest was taken to the aspects of usability and the necessary time periods for specific steps of the procedure. Usability was measured for specific time periods of the procedure assessment of the usability of the surgical team. In addition postoperative x-rays were evaluated for implant position, leg alignment for TKR and hip joint geometry for THR cases. Throughout the study for each assigned patient the procedure could be performed as planned. Several design inputs were identified for further improvement of the final system. Therefore time measurements of the first five cases were excluded. For the TKR cases the registration process of the last 5 cases was less than 3 minutes. The interval for the tibial resection was between 3 and 7 minutes (aligning tibial cutting block – end of tibial verification). The interval for the distal femur resection was between 7 and 11 minutes (aligning femoral cutting block – end of femoral verification). All 10 Patients showed a final leg alignment on the postoperative standing x-ray within the save-zone of +/− 3° from neutral alignment. For the THR cases the preoperative registration period including the femoral head resection and acetabular registration was between 7 and 12 Minutes. Each final measurement of the hip geometry was done in less than 2 minutes. The evaluation of the pelvic ap-x-ray pre- and postoperative showed equivalent measurements of the new hip geometry compared with the intraoperative measured values. No specific complications occurred throughout the study. In conclusion the BrainLAB–DASH-System has shown a high grade of usability and very short learning curve within this first clinical study. The use of a standard Apple® IPod-touch as a user interface seems to enhance the acceptance of the navigation technique. Equivalent precision compared to standard navigation systems have been demonstrated

Introduction. A recent report based on the NARA database (Nordic Arthroplasty Register Association) found that the 10-year survivorship of patients under 50 with traditional total hip arthroplasty was only 83% in 14,600 cases. The purpose of this study was to compare our experience using metal-on-metal hip resurfacing arthroplasty (HRA) to treat these patients. Methods. from May 2001 to Feb 2012, a single surgeon performed 1029 metal-on-metal HRA in 855 patients younger than 50 years old. Three different implants were used in consecutive groups of patients, first the Corin hybrid HRA (182); then the Biomet hybrid HRA (306); and finally the Biomet uncemented HRA (541). The primary diagnoses were OA (707); dysplasia (125); osteonecrosis (98); post-trauma (28); Legg-Calve-Perthes (27) and others (44). The average age was 43±6 years; 74% were men; the average BMI was 27±4; mean femoral component size was 50±4 (range 40–62); the average T-score was 0±1. 37% of our patients reported a UCLA Activity level of 9 or 10 (impact sports). Six died with causes unrelated to their HRAs. The rate of follow-up was 94%. Our patients were not selected by any criteria except the surgeon's technical ability to perform an HRA. Results. There were a total 42 failures: acetabular component loosening in 15 cases (8 before two years) femoral component loosening in 9 cases; femoral neck fracture in 5 cases; adverse wear related failure (AWRF) in 4 cases; deep infection in 3 cases; recurrent dislocation in 1 case; other causes in 5 cases. With revision of any component as the end point, the Kaplan-Meier survivorship rate was 94.9% at 8 years and 92.5% at 10 years for the entire group. We compared survivorship between groups at shorter follow-up intervals to determine if results were improving. The survivorship rate at 8 years for Biomet Hybrid group was 95.8%, which was significantly better than 89.1% for the earlier Corin Hybrid group; the survivorship rate at 5 years for the latest Biomet Uncemented HRA group was 98.7%, also better than 96.5% for the prior Biomet Hybrid group. (P=0.0001). Conclusion. Metal-on-metal hip resurfacing has less than half the 10-year failure rate of THR in young patients. As HRA technology and experience improve, our data suggests that the results further improve. HRA currently meets the NICE criteria for 10-year survivorship of implants while THR doesn't in young patients. Our HRA patients are allowed unrestricted activity, while THR patients are typically restricted. AWRF (0.4%) is a minor problem that has been blown far out of proportion to its significance. Patient selection against HRA in certain subgroups (women, small bearings, history of metal allergy) may not be advisable based on our results

The choice to use alumina in the manufacture of a low-wear THR bearing made by Boutin and its co-workers has proven its effectiveness in almost 35 years of clinical use. A continuous development process aimed to improve mechanical properties led to today’s materials that exhibit extreme high reliability. The recent introduction in clinical use of alumina matrix composites represents the latest evolution of alumina that thanks to high hardness, toughness, and bending strength allow to manufacture new design of ceramic components. Composites obtained introducing zirconia in the alumina matrix, known as Zirconia Toughened Alumina (ZTA) are candidate for use in THA bearings from a long time. A real breakthrough was represented by alumina ceramics toughened both by zirconia both by platelets nucleated in-situ during sintering (Zirconia-Platelet Toughened Alumina - ZPTA). The chemical composition and the microstructure of ZPTA were optimised to achieve a ceramic material joining strength of more than 1200MPa, Vickers hardness 1975, fracture toughness of 6,5 MPa m-1/2, andextremely low wear also in the most severe simulator tests performed in microseparation mode The paper reviews the improvements introduced in the technology of ceramic for arthoplasty, and their effects on the microstructural properties and on the performances of the past and actual generation of ceramic for THR bearings, and summarise the results obtained in the development of alumina matrix composites

Introduction: Hip resurfacing has been promoted as a procedure that results in a better outcome in sporting and work activity after surgery compared to total hip replacement (THR). Recently more standard THRs have offered the same large metal on metal joint articulation but using a standard stem. Method: Questionnaires were analysed from 125 metal on metal total hip replacement (THR) and 108 hip resurfacing (HR) patients regarding participation in sport and returning to work at a minimum of a year after surgery. Results: The two groups had similar mean age (61 vs 60) and pre-operative Oxford hip scores (41 vs 38). Seventy-one of 125 THR (57%) patients compared to 76 of 108 (70%) HR patients participated in sporting activity in the year after their surgery (fishers exact test, p value=0.04). When including only patients that played sport before their surgery 54 of 75 (72%) THR and 66 of 83 (80%) HR patients returned to same sporting activity level after their surgery (fishers exact test, p value=0.35). Of the patients that worked before surgery 35 of 44 (80%) THR patients compared to 70 of 74 (95%) HR patients returned work to after their surgery (fishers exact test, p value= 0.02). Conclusion: There was no difference in the proportion of patients who played sport prior to their surgery returning to sport. After hip resurfacing however more people took up a sporting activity and at a year post surgery a greater number of patients were taking part in sport after a hip resurfacing. Patients with a hip resurfacing were more likely to return to work after surgery

There is a critical need for safe innovation in total joint replacements to address the demands of an ageing yet increasingly active population. The development of robust implant designs requires consideration of uncertainties including patient related factors such as bone morphology but also activity related loads and the variability in the surgical procedure itself. Here we present an integrated framework considering these sources of variability and its application to assess the performance of the femoral component of a total hip replacement (THR). The framework offers four key features. To consider variability in bone properties, an automated workflow for establishing statistical shape and intensity models (SSIM) was developed. Here, the inherent relationship between shape and bone density is captured and new meshes of the target bone structures are generated with specific morphology and density distributions. The second key feature is a virtual implantation capability including implant positioning, and bone resection. Implant positioning is performed using automatically identified bone features and flexibly defined rules reflecting surgical variability. Bone resection is performed according to manufacturer guidelines. Virtual implantation then occurs through Boolean operations to remove bone elements contained within the implant's volume. The third feature is the automatic application of loads at muscle attachment points or on the joint contact surfaces defined on the SSIM. The magnitude and orientation of the forces are derived from models of similar morphology for a range of activities from a database of musculoskeletal (MS) loads. The connection to this MS loading model allows the intricate link between morphology and muscle forces to be captured. Importantly, this model of the internal forces provides access to the spectrum of loading conditions across a patient population rather than just typical or average values. The final feature is an environment that allows finite element simulations to be run to assess the mechanics of the bone-implant construct and extract results for e.g. bone strains, interface mechanics and implant stresses. Results are automatically processed and mapped in an anatomically consistent manner and can be further exploited to establish surrogate models for efficient subsequent design optimization. To demonstrate the capability of the framework, it has been applied to the femoral component of a THR. An SSIM was created from 102 segmented femurs capturing the heterogeneous bone density distributions. Cementless femoral stems were positioned such that for the optimal implantation the proximal shaft axis of the femurs coincided with the distal stem axis and the position of the native femoral head centre was restored. Here, the resection did not affect the greater trochanter and the implantations were clinically acceptable for 10000 virtual implantations performed to simulate variability in patient morphology and surgical variation. The MS database was established from musculoskeletal analyses run for a cohort of 17 THR subjects obtaining over 100,000 individual samples of 3D muscle and joint forces. An initial analysis of the mechanical performance in 7 bone-implant constructs showed levels of bone strains and implant stresses in general agreement with the literature

Background: Resurfacing is becoming increasingly popular as an option for primary hip arthroplasty. However, there is minimal documentation of objective post-operative outcomes which support the perceived benefits of resurfacing over traditional stemmed THR. Most comparative studies have reported differences in X-ray findings, such as component alignment and femoral offset, which only allow speculation of their relative effects on patient function. Studies have also reported general clinical outcomes following resurfacing, and although resurfacing shows promising medium term results, these studies have been largely subjective and have lacked a direct same study comparison with standard THR. Potential benefits of resurfacing include improved abductor muscle function, resulting from preservation of the femoral neck offset, and greater range of hip motion, resulting from the larger diameter bearings. Mont et al (2007) compared biomechanical outcomes during gait for individuals with unilateral resurfacing and standard arthroplasty and concluded that hip resurfacing yielded superior function, as defined by faster walking speeds. However, comprehensive data of 3-dimensional moments and hip kinematics was not presented and functional assessment was limited to gait analysis only. Methods: Kinematic and kinetic outcomes were evaluated for 28 individuals (age 40–60) with unilateral resurfacing (Durom, Zimmer) or standard stemmed THR (ceramic-on-ceramic Trident, Stryker) at 3 and 12 months following surgery. Data was collected using an 8 camera Vicon 612 motion analysis system and two Kistler force plates while subjects completed level walking and stair ascent and descent activities using a 4-step stair case, instrumented with a force plate on the second step. A lower limb marker set was used with pointer trial calibration of anatomical landmarks. 3-dimensional hip moments, angles and temporospatial parameters were compared and preferred motion patterns analysed. Results: Peak hip moments showed no statistically significant group difference during the ambulatory activities although slightly greater peak hip angles were achieved by those with standard THR. Stair negotiation highlighted greater differences in biomechanical outcomes between the groups than level gait analysis. Those with hip resurfacing exhibited less protective motion patterns and performed walking and stair negotiation at a faster pace. Conclusions: The greater diameter bearings of the resurfacing prosthesis do not appear to yield a greater functional range of motion post-operatively. Preserving the femoral offset with a hip resurfacing does not appear to benefit abductor muscle function. Statistically, both arthroplasty types demonstrate equivalent functional outcomes

Introduction: The hip resurfacing in younger patients is being performed more frequently in the UK. At the same time conventional Total Hip Replacement (THR) is also being performed.. We carried out a study to compare the patient satisfaction and outcome following Birmingham Hip Resurfacing (BHR) and Total Hip Replacement (THR) in patients below the age of 55 years. Methods: There were 93 BHR in 73 patients and 74 THR in 64 patients performed between February 1997 to June 2005.. Retrospective evaluation of notes and complications were identified. We carried out our study using Oxford Hip score and Modified WOMAC questionnaire by postal and telephonic survey. Results: We found that mean length of stay was 4.5 days for BHR and 6.4 days for THR patients. (P< 0.0001) The dislocation rate was 0% for BHR as oppose to 4% for THR. (P< 0.05) The mean Oxford Hip score improved from pre-operative 43 to 14 for BHR as oppose to 48 to 22 for THR patients. The mean modified WOMAC score improved from 21 to 8.4 for BHR as oppose to 25 pre-operative score to 12 for THR. We also found early and sustained improvement in these scores for BHR as compare to THR during their follow-up within 6 months to 8 years. The improvement in pain score was 100% following BHR as opposed to 84% for THR. Following BHR 70% patients were very active or active as oppose to only 30% of THR patients. Return to the work and sporting activities following BHR was at a mean of 9 weeks as oppose to 14 weeks following THR. (P < 0.05) The level of satisfaction was 98% following BHR as oppose to 84% following THR. (P=0.356)

Summary Statement. This data may help explain the variability in physical function after primary TKR as compared to primary THR. Introduction. Total knee replacement (TKR) and total hip replacement (THR) reliably relieve pain, restore function, and ensure mobility in patients with advanced joint arthritis; however these results are not uniform across all patient populations. We compared baseline demographic and symptom profiles in patients from a US national cohort undergoing primary TKR and THR. Methods. Patients undergoing primary TKR and THR between 7/1/2011 and 3/30/2012 were identified from the national research consortium which collects comprehensive data on enrolled patients from 120 surgeons across 23 states. Gathered data includes patient demographics, comorbidity (Charlson Comorbidity Index), operative joint pain severity, physical function (SF-36; Physical Component Score (PCS)), emotional health (SF-36 Mental Component Score (MCS)), and musculoskeletal burden of illness (Hip and Knee Disability and Osteoarthritis Outcome Scores; Oswestry Disability Index). Descriptive statistics compared baseline demographic and symptom profiles. Results. Our analysis compared 1362 primary TKR patients and 1013 primary THR patients. US TKR patients were significantly older (66.5 vs. 64.3 years), more obese (BMI 31.7 vs. 29.3), and less educated (p<0.005). TKR patients had higher rates of comorbidities, specifically diabetes, gastrointestinal ulcers, and cerebrovascular disease (p≤0.006). THR patients had significantly worse physical function (PCS 31.6 vs. 33.3), lower back pain (35.6% vs. 30.5% moderate-severe), and operative joint pain, stiffness, and function (p<0.005). Conclusion. US patients undergoing primary TKR are older with more comorbidities, however THR patient baseline functional and musculoskeletal limitations are significantly greater than primary TKR patients

Introduction. The benefits of femoral head-neck modularity in hip surgery have been recognized for decades. However, reports of head/neck taper fretting & corrosion has led to research being conducted, yet the clinical effect of these processes remains unclear. Whilst femoral head size, material and the characteristics of the taper have been a focus of research, potential contributing variables such as in vivo head-neck assembly technique on the performance of these connections is not clear. We performed an observational study to investigate variation in femoral head-neck taper assembly during surgery, with the initial focus being the number of head impactions. Methods. From May 2013 to October 2014, nineteen surgeons who specialized in hip surgery from a wide demographic (North America, Europe and Asia) participated in a video review on current surgical practice in total hip arthroplasty (THA). The surgeons were unaware of any specific parameter, including taper assembly, which would subsequently be analyzed. Twenty-seven THA surgeries were reviewed against a specific set of questions relating to factors in the modular femoral head-neck assembly process. The focus of the current study was the number of impaction blows to seat the modular femoral head on the implanted stem. Results. Variation occurred in the number of observed impactions used to assemble the components with an impaction range from 1 to 11 (Figure 1). The two most favored number of impaction strikes were a single strike (37% of reviewed cases) and three strikes (22% of reviewed cases). Further variability was observed between individual surgeon cases where number of strikes was different in each observed case. This occurred on two occasions with two different surgeons. The impaction number was found to be independent of the side operated on (left or right) and also with the surgeons region of origin. However, a higher proportion of European surgeons favored 1–3 impactions (92% of European cases) compared to their North American (28.5% of North American Cases) and Asian (42.8% of Asian cases) counterparts. The impaction number variation was also independent of the material of the femoral head, with both metal and ceramic heads demonstrating this observed variation (Figure 2). Discussion. This observational review into the current surgical practice of femoral head assembly has shown that there is clear variation in this aspect of the THR surgery. The number of impactions is not correlated to head material, but may be related to the surgeon's training or local practice environment. Conclusion. This observational review into the current surgical practice of femoral head assembly has shown a level of variation in the way the modular junction is assembled through impaction. Further investigation into other aspects involved in femoral head assembly is required to understand the potential impact that these surgical practice variations may have on the functional performance of the modular taper junctions in THR

Introduction:. Total knee replacement (TKR) and total hip replacement (THR) reliably relieve pain, restore function, and ensure mobility in patients with advanced joint arthritis; however these results are not uniform across all patient populations. Moreover, it is well established that knee replacement patients have outcomes inferior to those undergoing hip replacement procedures with lower rates of dissatisfaction with post-operative function and pain relief. We compared baseline demographic and symptom profiles in patients from a US national cohort undergoing primary TKR and THR to determine whether differences in demographic make-up, pre-operative symptoms, or pre-existing co-morbidities might contribute to these differences observed post-operatively. Methods:. A cohort of 2375 patients undergoing primary TKR and THR was identified from the FORCE national research consortium from all surgeries performed between July 1. st. 2011 and March 30. th. 2012. This set of patients was derived from 120 contributing surgeons in 23 US states. Gathered data included patient demographics, comorbidity (Charlson Comorbidity Index), operative joint pain severity (Western Ontario and McMaster Universities Arthritis Index (WOMAC)), physical function (SF-36; Physical Component Score (PCS)), emotional health (SF-36; Mental Component Score (MCS)), and musculoskeletal burden of illness (Hip and Knee Disability and Osteoarthritis Outcome Scores; Oswestry Disability Index). Using descriptive statistics, we compared the baseline demographic characteristics and symptom profiles of patients undergoing TKR (n = 1362) and those undergoing THR (n = 1013). Results:. In this large national sample, patients receiving knee replacements were found to be significantly older (66.5 vs. 64.3 years), more obese (BMI 31.7 vs. 29.3), and less educated (p < 0.005) than those undergoing THR. TKR patients had higher rates of medical comorbidities, specifically diabetes, gastrointestinal ulcers, and cerebrovascular disease (p ≤ 0.006). Conversely, THR patients had significantly worse physical function (PCS 31.6 vs. 33.3), lower back pain (35.6% vs. 30.5% moderate-severe), and operative joint pain, stiffness, and function (p < 0.005) when compared to those undergoing TKR. Conclusions:. US patients undergoing primary TKR are older with more comorbidities, however THR patient baseline functional and musculoskeletal limitations are significantly greater than primary TKR patients. These data may help explain the variability in physical function after primary TKR as compared to primary THR

Introduction: Metal on metal Hip Resurfacing Arthroplasty (MoMHRA) has gained popularity due to its perceived advantages of bone conservation and relative ease of revision to a conventional THR if it fails. This retrospective study is aimed at assessing the functional outcome of failed MoMHRA revised to THR and comparing it with a matched cohort of primary THRs. Method: Since 1999 we have revised 53 MoMHRA to THR. The reasons for revision were femoral neck fracture (Group A, n=21), pseudotumour (Group B, n=16) and other causes (Group C, n=16: loosening, avascular necrosis and infection). Average follow-up was 3 years months (1.2–7.3). These revisions were compared with 106 primary THRs which were age, gender and follow-up matched with the revision group in a ratio of 2:1. Results: The mean Oxford Hip Score (OHS) was 20.1 (12–51) for group A, 39.1 (14– 56) for group B, 22.8 (12–39) for group C and 17.8 (12–45) for primary THR group. In group A, there were three infections requiring further revisions. In group B, there were three recurrent dislocations, three patients with femoral nerve palsy and one femoral artery stenosis. In group C, there were no complications. The differences in clinical and functional outcome between group B and the remaining groups as well as the difference in the outcome between group B and control group were statistically significant (p < 0.05). Conclusions: THR for failed MoMHRA was associated with significantly more complications, operation time and need for blood transfusion for the pseudotumour group. In addition, the revisions secondary to pseudotumour also had significantly worse functional outcome when compared to other MoMHRA revisions or primary THR

Introduction. Mechanically-assisted corrosion of the head-neck junction present a dilemma to surgeons at revision THR whenever the femoral component is rigidly fixed to the femur. Many remove the damaged femoral head, clean the femoral taper and fix a new head in place to spare the patient the risks associated with extraction and replacement of the well-functioning femoral stem. This study was performed to answer these research questions:. Will new metal heads restore the mechanical integrity of the original modular junction after impaction on corroded tapers?. Which variables affect the stability of the new interface created at revision THR?. Materials and Methods. Twenty-two tapers (CoCr, n=12; TiAlV, n=10) were obtained for use in this study. Ten stems were in pristine condition, while 12 stems had been retrieved at revision THR and with corrosion damage to the trunnion (Goldberg scale 4). Twenty-two new metal heads were obtained for use in the study, each matching the taper and manufacturer of the original component. The following test states were performed using a MTS Machine: 1. Assembly, 2. Disassembly, 3. Assembly, 4. Toggling and 5. Disassembly. All head assemblies were performed wet using 50% calf serum in accordance to ISO 7206-10. During toggling, each specimen's loading axis was aligned 25° to the trunnion axis in the frontal plane and 10° in the sagittal plane (Figure 1). Toggling was performed at 1Hz for 2,000 cycles with a sinusoidal loading function (230N–4300N). During loading, 3D motion of the head-trunnion junction was measured using a custom jig rigidly attached to the head and the neck of each prosthesis. Relative displacement of the head with respect to the neck was continuously monitored using 6 high resolution displacement transducers with an accuracy of ±0.6µm. Displacement data was independently validated using FEA models of selected constructs. Results. The average micromotion of the head vs trunnion interface was greatest at the start of loading and stabilized after approximately 50 loading cycles at an average of 30.6±3.2µm (Figure 2). For CoCr couples, interface motion dropped by 17% when a pristine head was mounted on a corroded stem compared to a new stem (25.7±2.7µm (pristine stem), vs. 30.1±4.6µm (corroded stem), p= 0.4023) (Figure 3). However, addition of a new CoCr head with a corroded titanium stem led to an 73% increase in interface motion after assembly with a new CoCr head (Corroded: 43.4±9.8µm, Pristine: 25.2±7.0µm, p=0.1661). The resistance to head-neck disruption was 15% higher in TIALV/CoCr couples compared to CoCr/CoCr (TiAlV: 2558 ±63N, CoCr: 2226±99N, p=0.0111) and was not affected by the presence of corrosion of the trunnion (1% loss of strength in each case). Discussion. Corrosion at the trunnion does not disrupt the mechanical integrity of the junction when a CoCr head is replaced on a CoCr taper. We are less sure about the mechanical integrity of a TiAlV taper demonstrated by a trend towards increased micromotion at this junction. Further work is required to better elucidate the role of dissimilar metals in the mechanical integrity of the head-neck junction

Introduction: The goal of the study was to compare the squeaking frequencies of Ceramic-on-Ceramic THR in-vitro and in-vivo among patients who underwent THR. Method: Four patients, who underwent THR with a Ceramic-on-Ceramic THR (Trident. ®. , Stryker. ®. ) presented a squeaking noise. The noise was recorded and analysed with acoustic software (FMaster. ®. ). In-vitro 2 alumina ceramic (Biolox Forte Ceramtec. ®. ) 32 mm diameter (Ceramconcept. ®. ) components were tested using a PROSIM. ®. hip friction simulator. The cup was positioned with a 70° abduction angle in order to achieve edge loading conditions and the head was articulated ± 10° at 1 Hz with a load of 2.5kN for a duration of 300 cycles. Tests were conducted under lubricated conditions with 25% bovine serum and with the addition of a 3rd body alumina ceramic particle (200 μm thickness and 2 mm length). Results: In-vivo, recordings had a dominant frequency ranging between 2.2 and 2.4 kHz. In-vitro no squeaking occurred under edge loading conditions. However, with the addition of an alumina ceramic 3rd body particle in the contact region squeaking was obtained at the beginning of the tests and stopped after ~20 seconds (dominant frequency 2.6 kHz). Discussion and Conclusion: Squeaking noises of a similar frequency were recorded in-vitro and in-vivo. In-vitro noises followed edge loading and 3rd body particles and despite, the severe conditions, squeaking was intermittent and difficult to reproduce. The lower frequency of squeaking recorded in-vivo, demonstrates a potential damping effect of the soft tissues. No damage was observed on the components, however, the test duration was very short. Squeaking may be related to third body particles that could be generated by wear or impingement between the femoral neck and the metal back. Cup design seems to be of particular importance in noisy hip, leading to a high variability of squeaking rate according to the implants

The management of patients with displaced intra-capsular hip fractures is usually a hip hemiarthoplasty procedure. NICE guideline 124 published in 2011 suggested that Total Hip Replacement (THR) surgery should be considered in a sub group of patients with no cognitive impairment, who walk independently and are medically fit for a major surgical procedure. The Royal Devon and Exeter Hospital manages approximately 550 patients every year who have sustained a fracture of neck of femur, of which approximately 90 patients fit the above criteria. Prior to the guideline less than 20% of this sub-group were treated with a THR whereas after the guideline over 50% of patients were treated with THR, performed by sub-specialist Hip surgeons. This practice is financially viable; there is no apparent difference in the overall cost of treating patients with THR. The effect of adoption of the NICE guideline was examined using 100 % complete data from 12 month post operative follow up. Only the Hemi-arthroplasty patients were significantly less likely to have stepped down a rung of independent living. Both THR and Hemi-arthroplasty patients were significantly less likely to have stepped down a rung of walking ability, but there was no significant difference between THR and Hemi-arthroplasty groups. Revision rates remained negligible

Background: Whether to cross match or simply group and save for a primary THR is still a matter of debate. The argument in favour of cross match being immediate availability of blood and against it being wastage of resources, underutilization of cross matched samples etc. Patients & Methods: We retrospectively analyzed the records of 136 patients who underwent primary THR at Manchester Royal Infirmary in 2004. Result: Of the 136 patients, 104 had 220 units of blood cross matched. The average blood loss was 520 mls. The average pre op. Hb level was 12.8 g/dl while the average post op. Hb levels at 1, 3 & 5 days were 9.4, 9.9 & 10.1 gms/dl resply. Blood loss in patients on pre op. anticoagulant treatment (n = 44) was 596 mls while in the rest, it was 502 mls. The drop in Hb levels between the 2 groups was 3.6 gms/dl and 3.1 gms/dl resply. Patients with drain had an average drop in Hb level of 3.5 gms while it was 3.1 gms in others. The overall transfusion rate was 43.7 %. The most common reason for transfusion was asymptomatic low Hb (< 8 g/dl). Out of the 220 cross matched units, 99 (44.8 %) were transfused. Various probabilities like Cross-match to Transfusion ratio, Transfusion Probability & Transfusion Index were used to find out whether the cross matched units are used effectively. Discussion: The only factor which influenced the transfusion rate was pre-op. Hb value. 79 %of patients required transfusion when pre op. Hb level was < 12 gm/dl. Conclusion: 1. Group & Save is a safe policy for primary THR’s 2. Cross match only for patients with Hb of < 12gms/ dl. 3. Consider oral/IV iron therapy, autologous blood transfusion and retransfusion drain 4. Use of Aprotinin and transanamic acid reduces bleeding during surgery

Introduction and Aims: Minimal Invasive Surgery (MIS) in THR surgery offers potential advantages over standard techniques. A user-friendly surgical technique has been developed via the posterior approach to the hip using a single six to eight centimetre incision, and requiring no special instrumentation other than three long Homan retractors of standard design. The technique has been used to date in 80 sequential non-obese patients undergoing both uncemented and cemented THRs. Method: Five cemented and 75 uncemented THR procedures were performed in the lateral position via a segment of the standard posterior approach incision, centred just behind the greater trochanter. The pre- and post-operative SF12, WOMAC, Harris hip score and Pain score were assessed prospectively; blood loss, theatre time and intra-operative and post-operative complications were charted, and compared with 40 matched standard incision patients. Cup and stem component positioning was assessed radiologically. The Body Mass Index (BMI) and the incision length were charted in each patient. The post-operative time to full weightbearing and stair climbing was charted. Results: There was no statistical difference in SF12, WOMAC, Harris hip score and Pain score in the two groups of patients. Blood loss was slightly reduced, but theatre time and intra-operative and post-operative complications were not increased. Cup and stem positioning on x-ray was not compromised. Immediate full weightbearing was allowed, including stair climbing post-operatively in all patients. Conclusion: MIS THR via the posterior approach is a safe and reproducible procedure, for both cemented and uncemented prostheses. It requires no special instrumentation or long learning phase for the experienced hip surgeon. Blood loss, theatre time and morbidity have not been increased, allowing a rapid discharge program as a routine

Introduction: In the Swedish health care system waiting time for THR surgery has been unacceptable long. There are several hip disease related circumstances that generates costs for the society and the patient. In order to perform complete health economic analysis these costs have to be assessed. Patients and Material: Prior to THR surgery, 3500 patients from 20 hospitals were asked to complete a questionnaire regarding cost generating events related to the hip disease. Individual data on waiting time were collected. Follow-up questionnaire was administered one year postoperatively. Preliminary results: 2712 patients answered the pre-operative questionnaire. The sample was representative; mean age 69 years, 67% > 65 years (retirement age). Mean waiting time for orthopaedic consultation was 176 days and for surgery 312 days. 82% used any medication due to the hip disease. Among the non-retired patients 33% were on sick leave and 25% were on disability pension. 4% reported home-help service, 9% transportation service for disabled, and 46% had any home modification. 26% required help from relatives in various extents. The costs related to hip disease amounts to 8 000 Euro one year prior to surgery. Productivity loss constitutes 72% of total costs, health care costs 13%, municipal costs 6%, medication 1,5% and costs for relative care-taking 7,5%. Discussion: Productivity loss constitutes the principal cost for hip disease in patients eligible for THR surgery. One year on the waiting list costs equals the surgery cost. The waiting time for orthopaedic consultation and subsequent surgery is unacceptable long. Baseline cost data is important for further adequate health economic analyses

Background: Metal-on-metal (MOM) bearing surfaces with low diametric clearance possess a surface tension that prevents easy separation of the surfaces when lubricated. Potentially this ‘suction-fit’ may increase the torque required for dislocation. This study assessed the protective role of a MOM bearing surface as a single risk factor for dislocation. Method: Prospective data was recorded on a series of 229 patients undergoing 249 primary THR for osteoarthritis. From 1993–8, patients under 70 years old were routinely given a 28mm ceramic-on-polyethylene (COP) bearing surface. Due to a high dislocation rate (see results below), an alternative was sought (1998–2001) and a 28mm metal-on-metal (MOM) bearing system chosen. For all cases in both groups, the acetabulum was uncemented with a modular 10° posterior lip insert allowing the same primary arc range (Duraloc/PFC/ Ultima, Johnson & Johnson). The cemented femoral component was the same in all cases (Ultima). All operations were performed by the same surgeon using the posterior approach. Variables in patient and prosthesis factors were compared. Statistical analysis was performed by the Chi-square and student’s t-test where appropriate. Results: We identified 140 THR in 129 patients who received a COP bearing and 109 THR in 100 patients who received a MOM bearing. Nine of 140 (6.4%) COP bearings dislocated within 3 months of surgery compared to 1 of 109 (0.9%) in the MOM group (p=0.028). No significant differences were identified between groups when comparing factors relating to the patient or prosthesis. Discussion: This study has shown a high dislocation rate for a COP bearing that was reduced to a low dislocation rate by changing the bearing surface to a MOM design. A potential mechanism for this may be the ‘suction fit’ from the surface tension of the low clearance, high tolerance that the metal-on-metal bearing possesses, requiring increased torque to dislocate during impingement

Pelvic osteolysis secondary to polyethylene wear is a major complication following THR. Identification of implant specific characteristics associated with osteolysis is essential. The purpose of this study is to compare incidence of CT scan identifiable osteolysis in 2 groups of young, active patients following THR; one with multi-holed acetabular shells with screws, one with cups without screw holes. Between 1990–1993, 77 patients (85 hips) underwent THR with a cementless titanium, multi-holed shell with screws, modular, compression molded polyethylene and an uncemented titanium femoral stem. Average follow-up: 9 years, average age at surgery: 51 years. Between 1984–1987, 163 patients (183 hips) underwent THR with a cementless cobalt-chrome, solid shell, modular, heat-pressed polyeth-ylene liner and uncemented cobalt-chrome femoral stem. Average follow-up: 16 years, average age at operation: 52 years. All polyethylene was irradiated in air. At most recent follow-up, CT scans with metal suppression software was obtained to evaluate incidence of pelvic osteolysis. Patients classified: Group 1-no osteolysis, Group 2-cavitary osteolysis, Group 3-segmental osteolysis. Patients with titanium, multi-holed shells had: Group 1-50.0%, Group 2-38.7%, and Group 3-11.3%. Patients with cobalt-chrome, solid shells had: Group 1-59.3%, Group 2-33.3% and Group 3-7.4%. Although the patients with solid cups had much longer follow-up, less secure capture mechanism, less congruency between polyethylene and shell, and heat-pressed polyethylene, the incidence and extent of pelvic osteolysis was less than in the patients with multi-holed shell with screws. The presence of 6.5 mm cancellous screws is a serious independent risk factor for pelvic osteolysis following THR

Metal on Metal Hip Resurfacing Arthroplasty (MoMHRA) has gained popularity due to its perceived advantages of bone conservation and relative ease of revision to a conventional THR if it fails. Known MoMHRA-associated complications include femoral neck fracture, avascular necrosis/collapse of the femoral head/neck, aseptic loosening and soft tissue responses such as ALVAL and pseudotumours. This study’s aim was to assess the functional outcome of failed MoMHRA revised to THR and compare it with a matched cohort of primary THRs. Method: We have revised 53 MoMHRA cases to THR; the reasons for revision were femoral neck fracture (Fracture Group, n=21), soft tissue reaction (Pseudotumour Group, n=16) and other causes (Other Group, n=16: loosening, AVN and infection). Average followup was 2.9 years. These MoMHRA revisions were compared with 103 matched controls from a primary THR cohort; matched for age, gender and length of followup. We compared, using the MannWhitney U test, operative time (OT, measured in minutes), and Oxford Hip Score (OHS) between the revised MoMHRA groups and their individual controls. We also compared, using the Kruskal Wallis test, UCLA Activity Score in the revised MoMHRA groups. Results: There were no differences between the Fracture Group (mean OT 99.6, SD: 30.4; mean OHS 19.8, SD:9.2) and its controls (mean OT 95.9, SD: 31.8; mean OHS 17.3, SD: 7.5) nor between the Other Group (mean OT 129.4, SD: 36.7; mean OHS 22.2, SD: 9.4) and its controls (mean OT 104.4, SD: 39.2; mean OHS 20.3, SD: 10.1) in terms of OT and OHS. The Pseudotumour Group had significantly longer OT (mean 161.6, SD: 24.5, p< 0.001) and worse outcome (mean OHS 39.1, SD: 9.3, p< 0.001) than its controls (mean OT 113.1, SD: 51.7; mean OHS 20.0, SD: 9.2). In the Fracture Group, there were 3 infections requiring revisions. For the Pseudotumour Group, there were 3 recurrent dislocations, 1 femoral artery stenosis and 3 femoral nerve palsies. In the Other Group, there were 2 periprosthetic fractures. There was significant difference (p< 0.001) in UCLA scores between the MoMHRA groups. The Pseudotumour Group had the lowest mean UCLA score of 3.8 (SD: 1.89). The Fracture Group (mean: 7.0, S.D. 2.0) and the Other Group (mean: 6.7, S.D. 2.1) had similar UCLA scores. Discussion: The results demonstrate that outcome after revision of MoMHRA is dependent upon the indication for revision. Patients revised for soft tissue reactions had significantly worse outcome. Patients with soft tissue reactions are more likely to experience complications and require further surgical intervention. The pseudotumour associated revisions were associated with a significantly prolonged OT. The overall complication rate for the study groups was quite high, with 11 (21%) revised MoMHRA cases experiencing a complication. The Pseudotumour Group had a higher complication rate (37%)

The Birmingham Hip Resurfacing (BHR) has become increasingly popular for young active patients with severe OA of the hip. Although it has been in use in the UK since 1991, none were performed in NZ until late 2004. We have reviewed our initial results & have compared them to a similar group of patients who received conventional total hip replacement (THR) with ceramic-on-ceramic bearings. All patients aged 65 years or less undergoing either BHR or ceramic-on-ceramic THR under the care of the 2 senior authors (DRT & SAE) between October 2003 & July 2006 were included in the study. Patients were assessed pre- & post-operatively clinically & by questionnaires including the Harris Hip (HH) score & modified University of California Los Angeles (UCLA) activity score. Patients were also asked about activity levels prior to their hip symptoms. 59 BHR (38 resurfacings & 21 modular) and 55 THR were performed. 3 BHR & 1 THR patients were not able to be reviewed giving 97% follow up at 6–39 months. 3 patients had minor superficial wound infections (1 BHR & 2 THR). 1 BHR dislocated in recovery but has since been stable. 1 BHR has recently been revised for deep infection. We have had no peri-prosthetic fractures. BHR patients were slightly younger & were more active than the THR patients both pre- and post-operatively. Both group’s HH & UCLA scores improved significantly with surgery. BHR patients had a slightly greater improvement in HH score, but this failed to reach significance. When patients with single joint disease were considered, THR patients remained less active than prior to their hip symptoms whereas the BHR group’s activity scores matched their pre-disease level. All but 2 BHR patients and all of the THR patients were satisfied with their result at the time of review. Our initial experience with the BHR has been positive. Although we have achieved excellent results with both the BHR and with ceramic-on-ceramic THR, the results of the BHR do seem superior in relation to post operative activity levels. The two groups were, however, non-randomised and did differ with respect to age & activity levels, so these comparative results should be interpreted with some caution

The choice to use alumina in the manufacture of a low-wear THR bearing made by Boutin and its co-workers has proven its effectiveness in almost 35 years of clinical use. A continuous development process aimed to improve mechanical properties led to today’s materials that exhibit extreme high reliability. The recent introduction in clinical use of an alumina matrix composite developed by CeramTec and available under the trade name Biolox®Delta represents the latest evolution of alumina. This material allow new design in ceramic components thanks to its equilibrium among high hardness, high toughness, and high bending strength. Composites obtained introducing zirconia in the alumina matrix, known as Zirconia Toughened Alumina (ZTA) are candidate for use in THA bearings from a long time. A real breakthrough was represented by alumina ceramics toughened both by phase transformation both by platelets nucleated in-situ during sintering. Optimised processing and quality control led to optimised material behaviour. The chemical composition and the microstructure of Biolox®Delta were optimised to achieve a ceramic material joining strength of more than 1200 MPa, Vickers hardness 1975, fracture toughness of 6,5 MPam-1/2, and extremely low wear also in the most severe simulator tests performed in microseparation mode. The paper reviews the improvements introduced in the technology of ceramic for arthoplasty, and their effects on the microstructural properties and on the performances of the past and actual generation of ceramic for THR bearings, and summarise the results obtained in the development of alumina matrix composite Biolox® Delta

Hypothesis. The Synergy femoral component was introduced in 1996 as a second generation titanium proximally porous-coated tapered stem with dual offsets to help better restore femoral offset at THR. The purpose of this prospective study was to evaluate the long-term (minimum 10 year) clinical and radiographic results and survivorship of this femoral component at our institution. Methods & Analysis. From 1996 to 1999, 256 cementless Synergy femoral components were inserted and followed prospectively in 254 patients requiring THR. 185 were standard offset stems (72.3%) while 71 stems (27.7%) were high offset. The average follow-up was 11.2 years (range 10.0 to 12.9 years). Average age at index THR was 58.9 year. Two hundred and eight stems had standard porous coating while 48 had additional HA coating. Fifty-two cases were either lost to follow-up or had died prior to 10 years follow-up. Patients were followed prospectively using validated clinical outcome scores and radiographs. Kaplan-Meier survival analysis was performed. Results. All health-related outcomes were significantly improved from pre-operative with a mean Harris Hip score and WOMAC at last follow-up of 91.6 and 81.8, respectively. From the initial 256 femoral stems inserted, only 5 stems have been revised. Two stems have been revised for infection. Only one stem has been revised due to subsidence at nine months, likely as a result of a calcar fracture at the index THR. Two stems were revised for peri-prosthetic fracture as a result of patient falls. Radiographic review of remaining stems in situ identified no cases of loosening. Kaplan-Meier survivorship analysis of the femoral component, with revision for aseptic loosening, was 99.2% at 12 years. Conclusion. The Synergy femoral component, a second generation titanium proximally porous-coated tapered stem design with dual offsets, has demonstrated excellent clinical and radiographic results and long-term survivorship (99% at 10 years) at our institution

There is a lack of properly undertaken comparative studies of total hip replacement (THR). A randomised trial was established to examine the hypothesis that there are no important differences in clinical outcome at 2 years and at long-term follow-up between cemented and uncemented primary THR in middle aged patients.Eighty-three patients with 90 osteoarthritic hips were randomised to a cemented Exeter THR involving a matte or polished tapered stem (n=47, median age 68yrs) or an uncemented PCA proximally porous-coated cobalt-chrome stem and porous coated press fit cup (n=43, median age 66yrs). Patients underwent immediate full weight bearing post-operatively. The follow-up period is 8 to 16 years. The median Harris hip scores for the cemented and uncemented groups respectively were 92 and 95 at 2 years and 89 and 96 at long-term follow-up. Four cemented hips have been revised for aseptic loosening. There have been no failures of the polished stems. An analysis of a larger series of matt versus polished cemented stems also found that the results of the polished stems were superior. Four uncemented hips have been revised, two more recently for acetabular wear and osteolysis. There was a high rate of radiographic demarcation of the cemented cups. There were no important differences in the clinical scores between cemented and uncemented THR. Some matte surfaced femoral stems failed and this trend was confirmed by analysis of a larger series. Osteolysis around the uncemented acetabular components is a concern. Importantly immediate weight bearing was associated with good results of uncemented stems

Purpose. The purpose of the study was to determine the rate of conversion from RSA to THR in a number of Canadian centers performing resurfacings. Method. Retrospective review was undertaken in 12 Canadian Centers to determine the rate of revision and reason for conversion from RSA to THR. Averages and cross-tabulation with Chi-Squared analysis was performed. kaplan Meier survivorship was calculated. Results. A total of 2810 resurfacings were performed up to December 2008. 770 hips had a minimum of 5 year follow-up. The overall survivorship of this group was 97.8%. 80 patients underwent conversion to THR. Five resurfacing systems were used. The reason for failure is reported: 21 were for femoral neck fracture, 25 were for loosening, 9 were for deep infection, 3 foravn, 4 pseudotumors, 2 for impingement, 6 for groin pain and 10 for other reasons. The cumulative conversion rate is 2.8%. The survivorship was significantly different analyzed by gender. The 5 year female survivorship was 95.4% and for males was 97.7%. Surgeon experience proved to be a significant factor in conversion rates. Conclusion. The revision rate to date with this new technology suggests that with increasing experience hip resurfacing arthroplasty remains an acceptable option for the treatment of hip arthritis

We undertook a retrospective audit to assess the effectiveness of use of Quixil in reducing the amount of blood transfusion requirements following revision THR. As Quixil was used from mid 2007 for revision THRs, we looked at blood transfusion requirements for 1 year before introduction of Quixil and compared it with requirements after introduction of Quixil for a similar period. Method and Materials: 44 patients underwent revision THR by the senior author during the period from June 2007 – June 2008 (Quixil group) while 45 patients did not have Quixil during revision THR for the period May 2006 – May 2007 (Non-quixil group). In the quixil group, M: F = 18:26 and average age 75.3 (range: 63 – 88 yrs). In the non-quixil group, M: F = 17:28 and average age 71.3 (range: 47 – 85 yrs). The duration of surgery was similar in both groups. Blood loss during the operation was evaluated by measuring the volume in the suction apparatus and by estimating the amount of lost blood in the swabs at the end of the operation. Drains were not used in these procedures. All blood transfusions were recorded. Results: The average blood loss was 1010 mls (range: 300 – 2200 mls) in the quixil group vs. 1021 mls (range: 500 – 2000 mls) in the non-quixil group. The use of cell saver and intra-operative blood transfusion were similar in both groups. The mean pre-op Hb in quixil vs. non-quixil group was 13.0 g/dl (range: 9.7– 16.2) vs. 12.4 g/dl (range: 8.8 – 16.2). The mean post-op Hb in quixil group vs. non-quixil group was 10.2 g/dl (range: 6.4 – 13.2) vs. 9.1 g/dl (range: 5.3 – 12.9)(a difference of 1.1 g/dl). There was a difference in the blood transfused post-operatively between the two groups – 21 vs. 29 patients. Total units of blood transfused in quixil vs. non-quixil group were 60 vs. 86 (a difference of 26 units stastically significant) and total units of intra-op blood transfused in quixil vs. non-quixil group were 16 vs. 23 (a difference of 7 units). Limitations of the study: Retrospective study, Small numbers of patients. Conclusion: The use of fibrin tissue adhesive in revision total hip arthroplasty seems to be an effective and safe means with which to reduce blood loss and blood-transfusion requirements as well as prevent in the postoperative decrease in the level of hemoglobin

Introduction: The Birmingham Hip Resurfacing (BHR) system comprises both a BHR femoral head and a large modular femoral head for use should a total hip replacement be required. The modular femoral head has identical material chemistry, microstructure, spherical form, and surface roughness of the bearing surfaces of resurfacing femoral head and both BHR and THR devices share the same acetabular components. Hence, if the femoral component of a BHR needs revision surgery, the Birmingham hip system provides the potential of converting it to a THR without the need to also revise the well fixed cup. Although it stands to reason that the wear behaviour of the BHR and Birmingham THR will be similar, it is important to investigate the wear behaviour of new THR modular heads against worn BHR cups, representing revision of BHR to Birmingham THR without cup revision. The aim of this study is to assess the viability of the femoral component revision for BHR devices whilst leaving the acetabular components in situ in the pelvis. Materials and Methods: The wear and friction tests were conducted with pristine modular heads paired with BHR cups which had already undergone 5 million cycles (Mc) of wear in a hip simulator against BHR heads. Results and Discussions: The average wear rate of the new Birmingham THR modular heads against worn cups was 0.42 mm. 3. /Mc whilst the new BHR heads against new cups generated wear rate of 0.67 mm. 3. /Mc. Supported by the friction test results, it indicated that the new femoral heads paired with worn cup did not negatively affect the substantial amount of fluid-film lubrication that had developed over the course of the original test. Therefore, it is acceptable to use new femoral heads against worn cups, if the cups are not damaged, well fixed and correctly orientated

Purpose: A retrospective database analysis was conducted to. determine the extent to which the American College of Chest Physicians (ACCP) guidelines for VTE prophylaxis are followed after total hip replacement (THR) and total knee replacement (TKR) and. evaluate the incidence of VTE for patients receiving and not receiving prophylaxis according to ACCP guidelines (‘ACCP’ and ‘non-ACCP’, respectively). Method: A claims database associated with a large US health plan was linked to the Premier database, which provides details of in-patient medication use. Patients ≥18 years undergoing TKR/THR and enrolled in the health plan 90 days before and 90 days following discharge from hospitalization (or until death) were included. Patients were considered to have received ACCP-guideline prophylaxis if they:. received LMWH, fondaparinux, or VKA following surgery. initiated prophylaxis within one day of surgery (for THR patients) and. were prescribed prophylaxis for a minimum of ten days, or until the occurrence of major bleeding, VTE, or death. In addition, the number of DVTs and PEs occurring in ACCP and non-ACCP patients was recorded. Results: Of the 30,644 eligible patients from the health plan, 3,497 patients were linked to the in-patient database. Except for geographic indicators, there were no significant differences in demographics or baseline co-morbidities between those included and excluded from the final study sample. Of the 3,497 linked patients, 1,395 (40%) received ACCP prophylaxis. The number of DVTs occurring in the ACCP and non-ACCP groups were 28 (2.01%) and 79 (3.76%), suggesting that non-ACCP patients were almost twice as likely as ACCP patients to have a DVT (p=0.0521). The number of PEs occurring in the ACCP and non-ACCP groups were 2 (0.14%) and 25 (1.19%), respectively, suggesting that non-ACCP patients were 8.5 times more likely than ACCP patients to experience a PE (p< 0.0001). Conclusion: This study offers a unique perspective on ‘real-world’ prophylaxis patterns and clinical outcomes in THR/TKR patients. It suggests that 40% of patients received ACCP prophylaxis and that patients not receiving ACCP prophylaxis were almost twice as likely to have a DVT and more than eight times as likely to experience a PE

Introduction: The tissue sparing direct anterior approach (DAA/MicroHip) has been developed to improve patients’ rehabilitation and long-term function. But there was no long term evaluation up to now. The approach is aligned along the interneural plane of Smith-Peterson, with complete preservation of the musculotendinous structures. The femoral neck oeteotomy is performed without dislocation or resection of the joint capsule. Because we perform the DAA without traction table no additional traction was applied to the soft tissues. Methods: 55 patients underwent traditional THR (lateral approach) surgery In 2003 and 216 consecutive, non selected patients underwent THR with DAA. All Data was recorded prospectively including Haris Hip Score and gate analysis on a treadmill incorporating a dynamic force place. This data is compared to a similar group of patients operated by a traditional Harding approach. No other variables other than the surgical technique were changed for the protocol. Results: The two groups of patients were comparable in terms of age and BMI. Blood loss dropped by 42%. Hospital stay was reduced by 2.1 days (+/−0.6.) Cup inclination was 45.56 (+/−3.4) in the traditional group and 44.8 (+/−3.7) in the MicroHip group. The dislocation rate was lower in the MicroHip group, being 0.4% compared with 3.5 in the traditional group. Harris Hip score for the MicroHip group was 91.35 (78.3) at 3 months and 94.43 (86.4) at 1 year. At five years there was still a significant difference (p< 0.001) between the two groups. The gate analyze (excluding all patients with additional joint problems) in 98.8% of the DAA group no significant difference between the operated and the non-operated leg at five years. Discussion: Even if the DAA a demanding technique for THR and should be used only by high volume surgeons we could prove that there is a significant long-term benefit for the patients. The benefit is certainly higher for high demand patient, but also handicapped patients or very obese patients demonstrate a better outcome. The results indicate that the joint function is more influenced by the soft tissues then by the implant design. But implant design is never the less very important for long term survivorship

Purpose: The Synergy femoral component was introduced in late 1996 as a second generation titanium proximally porous-coated tapered stem with dual offsets (standard & high) to help better restore femoral offset at THR. The purpose of this prospective study was to evaluate the long-term (minimum 10 year) clinical and radiographic results and survivorship of this second-generation femoral component at our institution. Method: From December 1996 to December 1999, 256 cementless Synergy femoral components were inserted and followed prospectively in 254 patients requiring THR. 185 were standard offset stems(72.3%) while 71 stems (27.7%) were high offset. The average follow-up was 11.2 years (range 10.0 to 12.9 years). Average age at index THR was 58.9 years (range 19 to 86 years). Two hundred eight stems had standard porous coating while 48 had additional HA coating. Fifty-two cases were either lost to follow-up or had died prior to 10 years follow-up. Patients were followed prospectively using validated clinical outcome scores (WOMAC, SF-12, Harris Hip scores) and radiographs. Kaplan-Meier survival analysis was performed. Results: All health-related outcomes were significantly improved from pre-operative with a mean Harris Hip score and WOMAC at last follow-up of 91.6 and 81.8, respectively. From the initial 256 femoral stems inserted, only 5 stems have been revised. Two stems have been revised for infection. To date, only one stem has been revised due to subsidence at nine months following surgery likely, as a result of a calcar fracture occurring at the index THR. Two stems were revised for peri-prosthetic fracture as a result of patient falls at six months and 9.8 years post-op. Radiographic review of remaining stems in-situ identified no cases of loosening with all stems showing evidence of osseous integration. The Kaplan-Meier survivorship analysis of the femoral component, with revision for aseptic loosening, was 99.2%±0.008 at five, 10 and 12 years. Conclusion: The Synergy femoral component, a second generation titanium proximally porous-coated tapered stem design with dual offsets, has demonstrated excellent clinical & radiographic results and long-term survivorship (99% at 10 years) at our institution

Introduction: Although there is evidence that laminar flow operating theatres (LFOTs) can reduce the incidence of wound infection over standard operating theatres (STOTs) when no routine peri-operative antibiotics were used, the evidence for the use with concurrent parenteral antibiotics is less compelling. A number of prior studies have compared the bacterial load observed in LFOTs and STOTs by wound culture and air sampling during surgery. However many organisms responsible for low grade infection after THR are not readily identified on routine culture and may be detectable only by more sensitive techniques such as the polymerase chain reaction (PCR), a molecular biology test for the presence of bacterial DNA. The purpose of this study was to compare the wound contamination rate during THRs performed in STOT with that in LFOTs using PCR. Method: Patients undergoing primary THR for osteoarthritis without a history of joint infection were recruited for the study. Surgery was performed in either STOTs or LFOTs, using identical skin preparation solutions, surgical drapes and operating attire. Specimens of the deep tissue, taken at the beginning and end of surgery, were each immediately separated into two sterile containers, one sent for culture (aerobic, anaerobic and enriched meat broth) and the other frozen at minus 80 degrees Celsius for PCR at a later date. Results: In each theatre type, 40 specimens from 20 THRs were analysed by both PCR and culture (80 specimens and 40 THRs in total). Using PCR, bacterial DNA was identified on 12 of 40 specimens (30%) from STOTs. Of these 12, three were taken at the start of surgery and nine at the end of the surgery, equivalent to a 45% wound contamination rate (9 of 20). Only two specimens (5%), both taken at the end of surgery, were positive on enriched culture. In LFOTs, bacterial DNA was identified by PCR on eight of 40 specimens (20%). Of these eight, two were taken at the start of surgery and six at the end of surgery, equivalent to a 30% wound contamination rate (6 of 20). None of the specimens were positive on enriched culture. Discussions: We concluded that wound contamination of primary THR occurs frequently in both STOTs and LFOTs. Although STOTs showed evidence of more frequent wound contamination than LFOTs, with the numbers available, no significant difference was detected. These data are important in that they confirm that continued vigilance to technique continue to be important as significant wound contamination can occur despite the use of ultra clean air operating theatres

Introduction:. Femoral head surface roughness has been recognized as an important determinant of linear and volumetric polyethylene (UHMWPE) wear in total hip replacement (THR), particularly for metal heads. Fisher et al. 1. found that a 2- μm scratch with a 1- μm buildup of metal debris produced a 70-fold increase in the wear rate. Ceramic materials and hard-on-hard bearing couples have been introduced to provide more scratch resistance. However, THR bearing surfaces of all materials can become damaged during in vivo function, potentially impacting wettability. The purpose of this study is to quantify surface roughness as related to distinct damage types on retrieved femoral heads and to assess wettability of common bearing materials. Materials and Methods:. An IRB-approved archive of retrieved THR bearing components was queried, identifying 29 metal (CoCr) and ceramic (alumina, zirconia) femoral heads that had articulated with UHMWPE and ceramic acetabular liners, respectively. Mean in vivo functional duration was 5.5 ± 4.5 years (range, 1 month to 27 yrs), and patient age and weight averaged 68 ± 12 years (range, 36–81) and 72 ± 21 kilograms (range, 52–123), respectively. Retrieval reasons were dislocation (18), loosening (4), polyethylene wear (2), infection (1), squeaking (1) and unknown (3). Damage appearance and surface roughness were evaluated in a grid pattern of 49 zones distributed across the bearing surface of each head using optical microscopy to identify Mode-1 or Mode-2 wear and a non-contact interferometer (NT2000 & NPFLEX, Bruker Corp.) Wettability of smooth and rough CoCr and alumina materials was assessed using contact angle measurements (DSA30, Krüss USA). Results:. Among the metal heads, scratching was the most common damage (Mode-1) and was visualized on over 90% of all heads. Metal transfer and discoloration (Mode-2) damage, confirmed as titanium deposits, was visualized on 79% of dislocated heads. Zones with metal transfer had significantly higher surface roughness compared to zones without this damage (Table 1, p < 0.001). Among the ceramic heads, Mode-1 wear was visualized as a long, narrow wear region consistent with stripe wear. 2. and metal transfer (Mode-2) was visualized as dark smears similar to previous studies. 3. Areas of roughening (Mode-1 & Mode-2) exhibited significantly higher surface roughness than areas without such damage (Table 2). When comparing wettability, the contact angle for alumina (32.8°) was lower than CoCr (54.5°) and both materials had significantly higher contact angles with increased surface roughness. Conclusions:. Damage mechanisms leading to Mode-1 and Mode-2 wear were visualized on both metal and ceramic heads, leading to significant increases in surface roughness. However, the surface morphology of each damage mode differed between material types (Figure 3). These results, along with the empirical evidence relating surface roughness and wettability, have implications for wear and the ability to maintain suitable fluid films between bearing surfaces. Continued investigation into clinical phenomena possibly related to these parameters, such as squeaking in ceramic-on-ceramic bearings. 4. or accelerated wear in metal-on-metal bearings,. 5. is warranted

Metal-on-metal articulations are increasingly used in THR. Hypersensitivity reactions to the metal ions can occur. The symptoms and signs are similar to a patient presenting with an infected prosthesis. Correct diagnosis before revision surgery is crucial to implant selection and operation planning. We present a practical approach to this diagnostic problem. The history, clinical findings, hip scores, radiology, serum metal ions, ESR, C-RP, hip arthroscopy and aspirate results, synovial fluid metal ion levels, labelled white cell/colloid scan, 99m-technetium scan, revision hip findings and histology of a typical patient who had an allergic response to a metal-on-metal hip articulation are presented, and how the findings differ from a patient with an infected implant. Clinical examination, hip scores and serum metal ion levels were repeated one year after revision of the metal-on-metal hip articulation to a ceramic-on-ceramic. In hypersensitivity, the periarticular tissues undergo lymphocyte-dominated infiltration, the histology differs from that found in infection. The white cell labelled/colloid scan also uses this difference for diagnosis. Hip aspiration is the single best investigation for infection. Conclusion: There is no single investigation available in most hospitals that will reliably differentiate infection from allergy in the painful THR. Hip aspiration, labelled white cell/colloid scan and histology obtained from hip arthroscopy biopsy are the most useful investigations

Studies using roentgen stereophotogrammetric analysis (RSA) have shown that the femoral components of cemented total hip replacements (THR) migrate distally relative to the bone, but it is not clear whether this occurs at the cement-implant or the cement-bone interface or within the cement mantle. Our aim was to determine where this migration occurred, since this has important implications for the way in which implants function and fail. Using RSA we compared for two years the migration of the tip of the stem with that of the cement restrictor for two different designs of THR, the Exeter and Charnley Elite. We have assumed that if the cement restrictor migrates, then at least part of the cement mantle also migrates. Our results have shown that the Exeter migrates distally three times faster than the Charnley Elite and at different interfaces. With the Exeter migration was at the cement-implant interface whereas with the Charnley Elite there was migration at both the cement-bone and the cement-implant interfaces

Background. It is hypothesised that good torsional resistance of the acetabular cement mantle can increase the stability and longevity of cemented THR. Surgeons aim to achieve this by drilling keyholes (KH) in the acetabulum for the cement to penetrate. This study aims to reduce the surgical variability by investigating the influence of KH diameter on torsional resistance for a range of acetabular diameters. Methods. Three most common diameters of acetabula were tested (50, 54 and 58 mm) to compare three types of KHs: A) 3 × 12 mm diameter, 120° apart, 6 mm deep blind holes; B) 6 × 6 mm diameter, 60° apart, 6 mm deep blind holes; C) 6 × 6 mm diameter, 60° apart, through holes. An anatomically accurate experimental rig to simulate the implanted acetabulum was used, it allowed the torque strength of a cement mantle to be measured. The cups were cemented into the rig to create a 4 mm mantle and left to cure for 24 h at room temperature. Each sample was tested in the torque rig by applying a ramp displacement at 1.5 °/min until failure. The test was repeated four times for each acetabulum-keyhole combination. Peak torque was used for quantifying torsional resistance. Results. The mean and standard deviation peak torque for the A keyholes was 194 Nm (25.7), 251 Nm (25.3) and 334 Nm (20.9) for 50, 54 and 58 mm respectively; for the B keyholes the peak torque was 146 Nm (54.0), 143 Nm (48.6), 123 Nm (29.5); and for the C keyholes the peak torque was 208 Nm (6.0), 278 Nm (25.5), 244 Nm (74.1). Mann-Whitney test detected significant differences only between A and B groups at 54 mm (p = 0.021) and 58 mm (p=0.021). The torsional resistance increased with acetabular diameter only for the A keyholes (Kruskal Wallis Test, p = 0.01). Conclusions. The larger keyholes provided more consistent and substantially higher peak torque values. The difference was more evident with the increasing acetabular diameter. The large variability in the B keyholes was caused by poor cement penetration, this could potentially be the case clinically. C keyholes were an improvement, yet there were still consistency issues for the larger acetabulum. The limiting factor was the cement-cup interface, which is also where the failure occurred (except for most of the B keyholes and 58 mm acetabulum C keyholes). Level of Evidence. II b

Introduction: Implant loosening/pseudartrhosis after THR/TKR with large femoral bone defects is associated with pain and immobilization in a wheelchair. In these cases a total femur replacement (Combined total hip and knee replacement connected with an intramedullary rod) can be a therapeutic procedure as known from tumor surgery. We describe this technique and results with in a case serie of patients. Study Type: Monocentric prospective case serie. Patients and Methods: All patients who had a total femur replacement were followed regularly after 3, 6 months, 1, 3 and 5 years. The follow up was documented with clinical examination, x-rays and validated questionnaires. Indications were loosening after stem revisions (THR), pseudarthrosis and loosening of femoral component after TKR, pseudarthrosis and instability after THR and fracture. For every case the implants were planned with a total leg x-ray and manufactured (Link). The implants were removed and the knee and hip joint prepared. The approach was performed with two incisions (knee, hip) to reduce the invasivity. The implantation started with the knee implants connected with the intramedullary rod and was finished with the hip implants. Postoperative weight bearing was following pain. Results: Included were 5 cases of total femur replacement in 4 patients (three women, age from 54 to 69) with a follow up between 12 to 94 months, average 3.5 years. Three cases with stem loosening after THR and revisions before, one case with loosening and pseudarthrosis after TKR, one with pseudarthrosis and instability after THR with femur fracture. Every patient had 2–4 interventions of the affected joint before. The pain diminuished significant in all patients in the questionnaires and the pain medication could be reduced substantially. All patients gained mobility already three months after the procedure, every patient could walk with crutches. No patients needed to be reoperated in the follow-up period. Every patient could keep the mobility over the the follow-up time. Two patients reported some pain in the knee. Radiologically the defects of the femur were partially consolidated and we could not see further bone loss. Conclusion: Total femur replacement can be used also in selected patients with large bone defects after arthroplasty (THR/TKN) and loosening or pseudarthrosis. The patients profit from the reduction of pain and the gain in mobility

From 01/1988 to 04/2001 224 THR were performed assisted by a surgical robot (ROBODOC). The short term run of 5 years should reveal, if any benefit ore disadvantage could be detected comparing Robodo chips with hand -broached hips. In all 224 cases a straight stem prosthesis with a proximal sleeve was used (S-Rom-Prosthesis). The cup was implanted manually (RM-Cup). The average follow up has been 5 years (4,0–6,2 years). At the last investigation 3 patients had died, 6 patients could not be reached. 215 patients (96%) were examined. According to Merle d’Aubigné pain and walking ability were mesured with a maximal score of 12 points. Robot assisted hip surgery surely offers an improved primary stability of the stem because of the outstanding precision. Missing stem loosening after 5 years seem to promiss a longer survival rate. To avoid a high learning curve certificated qualifying courses are compulsory

Dislocation is the most relevant early complication after primary total hip replacement (THR) in literature. Many factors have been advocated for dislocation, either surgeon-related either patient-related. Component positioning seems to be of major importance in determining dislocation. We evaluated 152 randomised THR with a CT study between 985 THR done at our Institute since november 2004 to november 2006. 152 randomised primary THR on a total of 985. The same prosthetic pattern (head size, stem, cup). Lateral approach with total capsulectomy and external rotator tendon resection. All 152 patients underwent a post operative standardized CT study assessing cup antiverion and inclination angles and stem antiversion angle. Dislocated patients where furthermore analysed for any detail concerning their procedure and follow-up. A safe zone was then deduced for safer positioning. During the follow-up period dislocation occurred in 5 hips (only one in the randomised group) assessing our rate of dislocation at 0.5%. All dislocation were managed with closed reduction and an articulated hip brace. No open reduction or revision surgery were further needed. The mean cup abduction was 47° in the dislocated hips and 49° in the control group. Mean cup anteversion was 29° in both groups. The mean stem anteversion was 8.2° in the dislocated group and 3.1° in the control group. No statistical difference could be reached between dislocation and cup positioning. A correlation between hip dyspalsia (Crowe II) as primitive diagnosis and dislocation could be reached considering all the THR procedures. In THR inappropriate cup and stem positioning is considered an important risk factor of postoperative dislocation. Accurate and reproducible measurement is mandatory for implant positioning evaluation. Conventional radiographs cannot provide accurate and reproducible measurement. CT can provide a precise measurement of prosthetic components. Several studies failed to demonstrate a correlation between component positioning and dislocation often because of small number of patients and many bias. We tried to reduce bias using the same prosthetic pattern and the same surgical approach. Notwithstanding we could not reach a statistical difference in term of prosthetic positioning between dislocated and control group. Perhaps the dislocated group was too small to have a statistical meaning. We could determine a Safe Zone of cup and stem positioning for our patients: cup anteversion between 24° and 33°, cup inclination between 42° and 50°, stem anteversion between −3° and 10°. Dislocation is the main early complication after THR. Its etiology depends on many factors. Sometimes the cause can’t be identified. Orientation of prosthetic components may be responsable for dislocation but its truly correlation can be hard to be assessed. In this study we found no correlation between implant positioning and occurrence of dislocation, but we defined a tighter Safe Zone than previous reported, in which the risk of dislocation is nought. A correlation between hip dyspalsia (Crowe II) as primitive diagnosis and dislocation could be reached

A multicentre retrospective study of 879 total hip replacements (THR) was undertaken to investigate any differences in outcome between trainee surgeons and consultants. The effect of trainee supervision was also assessed. The primary outcome measures were survivorship and the Harris Hip Score (HHS). Length of stay was a secondary outcome. Patients were evaluated pre-operatively and at 1, 3, 5, 7 and 10 years post-operatively. Surgical outcome was compared between junior trainees, senior trainees and consultants. The effect of supervision was determined by comparing supervised and unsupervised trainees. There was no significant difference in post-operative HHS among consultants, senior and junior trainees at 1 year (p=0.122), at 3 years (p=0.282), at 5 years (p=0.063), at 7 years (p=0.875), or at 10 years (p=0.924) follow up. Additionally there was no significant difference in HHS between supervised and unsupervised trainees at 1 year (p=0.220), 3 years (p=0.0.542), 5 years (p=0.880), 7 years (p=0.953) and 10-year (p=0.787) follow-up. Comparison of surgical outcome between the supervised and unsupervised trainees also shows no significant difference in hospital stay (p=0.989), or implant survival years (p=0.257). This study provides evidence that when trainees are appropriately supervised, they can obtain equally good results compared with consultants when performing THR

Aim. The purpose of this study was to perform a randomised controlled trial (RCT) to compare the >20 year outcomes of cemented versus cementless Mallory Head total hip replacements (THRs). Methods. Two hundred and fifty patients with unilateral osteoarthritis of their hip, a mean age of 64 years and 48% of whom were female were randomised to receive either a cemented (n=124) or cementless (n=126) THR. Results. At >20 years follow-up, the cementless Mallory Head THR outperformed its cemented counterpart in terms of overall Kaplan Meier survivorship (p=0.01), socket survivorship (p=0.009) and stem survivorship (p< 0.0001). Age significantly affected acetabular socket revision rates for both cementless (>65 - 12% versus < 65 - 36%, p=0.003) and cemented (>65 - 19% versus < 65 - 55%, p< 0.0001) sockets. Male gender adversely affected cementless (males - 31% versus females - 12%, p=0.01), but not cemented (males - 35% versus females - 36%, p=1.000) socket survivorships. For the femoral stems, age did not affect cementless stem survivorship (>65 - 0% versus < 65 - 2%, p=0.465), but did so with cemented stems (>65 - 16% versus < 65 - 33%, p=0.001). Gender did not influence cementless or cemented stem survivorships. Conclusion. This RCT has demonstrated that cementless THRs offer significantly better overall, socket and stem survivorships at 20 or more years. The cementless tapered femoral stem performed particularly well with 100% survivorship at 20 years, excluding infections. Caution should be taken in generalising these results to other cemented and cementless THRs

We want to show our results of infected THR in the years from 2006 to 2008. We use an algorithm similar to Mc Phersons’s:. In early cases with not affected surrounding tissue we prefer the one stage procedure:. When there are no radiolucent lines in X-ray und the Scan does not show any tracer enhancement we perform synovectomy and replacement of the poly liner. If soft tissue does not have an inflammation and only the bony bed is affected, we perform a one stage procedure with use of antibiotic augmented morcelliced bone graft. We use freeze-dried cancellous bone granula from a commercial tissue bank which are bathed for 30 minutes in a combination of Tobramycin and Vancomycin which is placed into the interface of implant and bony bed. In chronic cases with affected soft tissue we treat the patient with a two stage exchange by use of a so called intermediate spacer and the definite revision after 3 months. The intermediate spacer contains a stainless steel rod coated by Gentamicin bone cement (Tecres company) in the shape of a prosthesis. This provides the release of antibiotics into the surrounding tissue. We treated 36 patients:. 18 patients were treated by use of a single procedure and 15 could be healed in 5 cases we could heal the patients by synovectomy and change of the poly liner. 10 cases could be healed by a THR revision with antibiotic augmented morcelliced bone graft. in two cases a two stage treatment was necessary after a synovektomie and change of poly liner. one patient was treated by synovektomy first, after persistent inflammation a THR Revision with antibiotic augmented morcelliced bone graft was performed and finally she could be healed by a two stage procedure. 20 patients were treated by a two stage THR with an intermediate spacer. 17 patients could be healed (three cases included from failed single procedure group). 3 patients are changed to a Girdlestone Hip (one died by reason of neoplasma, one could not be healed despite 4 revision with spacer, one could not be operated as he had chronic cardiac disease and ~prostatae). 1 patient get a permanent head-spacer as the femur prosthesis (Lord) could not be revised based on cardiac and pulmonary disease. Using Mc Pherson’s algorithm we could be successful with a single stage procedure in 15 from 18 cases. The remnant three patient could be healed by a two stage procedure. Only 4 patient could not be healed by a two stage procedure which was performed for 20 times. As we were successful too in three cases by treating chronic periprosthetic hip infection with a single procedure by using antibiotic augmented bone granula, investigation are requested to prove if this procedure could be postulated for all chronic periprothetic infections too

Introduction. There is a paucity of research investigating the effect of the experience of the operating surgeon on the long term function and survivorship of total hip replacements (THR). With the advent of individualised surgeon data being available to patients via the National Joint Registry, the desire to avoid complications and poor performance grows. This potentially reduces the availability of operative opportunities for trainees as consultants seek to ensure good results. Method & Results. A multicentre retrospective study of 879 THR was undertaken to investigate any differences in outcome between trainee surgeons and consultants. The effect of trainee supervision on the surgical outcome was also assessed. The primary outcome measures were survivorship and the Harris Hip Score (HHS). Rates of deep infection and dislocation were also recorded. Patients were evaluated pre-operatively and at 1, 3, 5, 7 and 10 years post-operatively. Surgical outcome was compared between junior trainees, senior trainees and consultants. The effect of supervision on final outcome was determined by comparing supervised and unsupervised trainees. 66.4% of patients were operated by consultants, 15.7% by junior trainees (ST3–5 equivalent) and 16.8% by senior trainees (ST6–8 equivalent). 10 year implant survival rates were; consultants 96.4 %, senior trainees 98.0 % and junior trainees 97.1%. There was no significant difference in post-operative HHS among consultants, senior and junior trainees at 1 year (p=0.122), 3 year (p=0.282), 5 year (p=0.063), 7 year (p=0.875), or at 10 years (p=0.924). There was no significant difference in HHS between supervised and unsupervised trainees at 1 year (p=0.220), 3 year (p=0.0.542), 5 year (p=0.880), 7 year (p=0.953) and 10-years (p=0.787). Comparison of surgical outcome between the supervised and unsupervised trainees also shows no significant difference in implant survival years (p=0.257). Conclusion. This study provides evidence that when trainees are appropriately supervised there is no negative effect on patient outcomes

Autologous drains are used frequently in total knee replacement surgery but not in total hip replacement surgery (THR). Previous studies have shown that these drains are not cost effective in THR surgery. We studied the effectiveness of autologous drains in THR surgery compared with normal suction drains. All the patients had an uncemented hip. The Bellovac®A.B.T (Astra) autologous drainage system was used. Patients using the drains were studied prospectively and the volume of drainage, volume of autotransfusion, amount of homologous blood transfused and the hospital stay were all recorded. A group of patients who had normal suction drains were studied retrospectively to determine the transfusion rate and hospital stay using these drains. In the group using standard suction drains there were 43 patients with a mean age of 72. The mean drainage was 641 ml (Range 500 – 1070). 10 patients out of 43 had a transfusion (Transfusion rate 23%). A total of 21 units of blood were used. The mean hospital stay was 14 nights. In the group using autologous drains there were 38 patients with a mean age of 67. The mean drainage was 703 ml (Range 200 – 1700), and of this the mean volume of blood that was given back to the patient was 445 ml (Range 50 – 1050). 2 out of 38 patients have required a blood transfusion, a transfusion rate of 5 % . This reduction in transfusion rate is significant (p< 0.005). The mean hospital stay was 9 nights. The difference in the hospital stay was not statistically significant. Using the autologous drainage system in uncemented total hip replacement surgery reduces the need for a homologous blood transfusion. It is simple and easy to use and avoids the complications of a blood transfusion. It was also found to be cost effective

The world’s clinical experience of highly cross-linked UHMWPE cups (HCLPE) lies in the cemented THR experience beginning in Japan (H, Oonishi), then South Africa (CJ. Grobbelaar) followed by England (M. Wroblewski). The South-African THR concept was to cross-link RCH1000 to a depth of only 300um with 10 Mrad radiation dose in a pressurized acetylene atmosphere. Subsequent sterilization was 3 Mrad in air. The modified Charnley stem had a 30 mm stainless-steel head. Between 1977 and 1983, over 1,000 cases had been implanted by surgeons Grobbelaar and Weber (Grobbelaar, SABJS-99). Analysis has been performed on 100 survivors with follow-up 14 – 21 years. In the Pretoria series, there were only two of 64 cases with revision for granulomas and in the Johannesburg series two of 39 survivors with wear-related problems. Wear was only measurable in nine of 39 cases analyzed radiographically and total linear wear varied from 0.7 to 1.5 mm. We have had the first-time opportunity to perform the retrieval analysis on Dr Weber’s cases. We now have & #65298; cases of revised cups and one sample off the shelf. These were examined by SEM to examine the microwear phenomena of the HCLPE surfaces. On the peripheral of the load-bearing area, the machine tracks were folded and their edges became fibrillated, some nodules, ripples, fibrils and folds (with attached fibrils) were observed. Fibrils were small in size and quite rare. Multi-oriented scratches and delaminations were sometimes observed. This study is the first time review for the retrieval analysis on Dr. Weber’s HCLPE cases. The SEM study showed that the load-bearing area had very little wear evident after 20 years. This confirms the clinical and radiographic observation of Dr. Weber. While the retrieval data to date includes only 2 HCLPE cups, these results are encouraging

Objectives. To investigate psychosocial and biomedical outcomes following total hip replacement (THR) and to identify predictors of recovery from THR. Methods. Patients with osteoarthritis (OA) on the waiting list for primary THR in North West England were assessed pre-operatively and at six and 12 months post-operatively to investigate psychosocial and biomedical outcomes. Psychosocial outcomes were anxiety and depression, social support and health-related quality of life (HRQoL). Biomedical outcomes were pain, physical function and stiffness. The primary outcome was the Short-Form 36 (SF-36) Health Survey Total Physical Function. Potential predictors of outcome were age, sex, body mass index, previous joint replacement, involvement in the decision for THR, any comorbidities, any complications, type of medication, and pre-operative ENRICHD Social Support Instrument score, Hospital Anxiety and Depression scores and Western Ontario and McMaster Universities osteoarthritis index score. Results. The study included 206 patients undergoing THR. There were 88 men and 118 women with a mean age of 66.3 years (. sd. 10.4;36 to 89). Pain, stiffness and physical function, severity of OA, HRQoL, anxiety and depression all improved significantly from pre-operative to 12-month assessment (all p < 0.001), with the greatest improvement occurring in the first six months (all p < 0.001). The predictors that were found to influence recovery six months after THR were: pain (p < 0.001), anxiety (p = 0.034), depression (p = 0.001), previous joint replacement (p = 0.006) and anti-inflammatory drugs (p = 0.012). Conclusions. The study identified the key psychosocial and biomedical predictors of recovery following THR. By identifying these predictors, we are able to identify and provide more support for patients at risk of poor recovery following THR. Cite this article: Bone Joint Res 2013;2:248–54

Introduction: The Scottish Arthroplasty Project (SAP) publishes an annual report including infection rates post-arthroplasty having obtained their results from the patients’ ICD-10 codes. The aim of this project was to validate the THR infection rate for one unit as published in the 2006 Scottish Arthroplasty Project (SAP) Report. Method: The details of the SAP results were obtained. The BGH keeps its own record of post-operative THR infections; only those that met the dates and criteria of the SAP 2006 report were included and compared. The ICD-10 coding status was analysed in more detail. Results: Published rate of infection in the 2006 SAP report after total hip replacement is three times lower than the unit recorded. 12 patients were eligible (1.49% infection rate), the SAP report recorded 4 cases of infection. The SAP searches for infection only using three ICD-10 codes. Six ICD-10 codes had been used to classify these 12 patients. Discussion: A recent cardiac surgery study comparing postoperative mortality rates from hospital statistics with the central cardiac database statistics found an over reporting by the national central database.* We have found the reverse with a threefold under calculation in the national report. However the unreported figures still do not place BGH as an outlier. The reasons for the discrepancy are multifactorial; but include poor coding practice, narrow range of code searching and difficulties in diagnosing infection. This audit shows that investigating the results of not only the outlying units but also randomly picking those who appear to have excellent results is worthwhile

Introduction. The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998 and femoral heads larger than 32mm in diameter introduced 2004. The purpose of this study was to re-assemble a previous multi-center patient cohort in order to evaluate the radiographic and wear analysis of patients receiving this form of highly crosslinked polyethylene articulating against large diameter femoral heads at a minimum of 10 years follow-up. Methods. Two centers contributed patients to this ongoing clinical study. Inclusion criteria for patients was: primary THR; femoral heads greater than 32mm; minimum 10 year follow-up. 69 hips have been enrolled with an average follow-up of 11.2 years (10–15), 32 females (50%). Wear analysis was performed using the Martell Hip Analysis software. Radiographic grading was performed on the longest follow-up AP hip films. The extent of radiolucency in each zone greater than 0.5mm in thickness was recorded along with the presence of sclerotic lines and osteolysis. Results. Wear analysis: Using the average of the slopes of the individual regression lines, the wear rate was 0.004±0.094mm/yr. Using the early to latest film method, the wear rate was 0.035±0.076mm/yr. Radiographic analysis: Acetabular side: the greatest incidence of radiolucency occurred in zone 1 at 27%; sclerotic lines had a less than 2% incidence in any of the 3 zones; there was no identified osteolysis. Femoral side: the highest incidence of radiolucencies was in zones 1 and 3, 7% and 4%; sclerotic lines were rare in any zone, maximum in zone 3, 4%; there was no identified osteolysis. Conclusion. The wear of this form of irradiated and melted highly crosslinked polyethylene remained at levels lower than the detection limit of the software at minimum 10 year follow-up and there was no identified osteolysis

Introduction. The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998. Numerous publications have reported reduced wear rates and a reduction in particle induced peri-prosthetic osteolysis at short to mid-term follow-up. The purpose of this study was to re-assemble a previous multi-center patient cohort in order to evaluate the radiographic and wear analysis of patients receiving this form of highly crosslinked polyethylene articulating against 32mm femoral heads or less at a minimum of 13 years follow-up. Methods. Inclusion criteria for patients was a primary THR with femoral heads 32mm or less and a minimum 13 year follow-up. 139 hips have been enrolled with an average follow-up of 13.7 years (13–16), 80 females (57%). Wear analysis was performed using the Martell Hip Analysis software. Radiographic grading was performed on the longest follow-up AP hip films. The extent of radiolucency in each zone greater than 0.5mm in thickness was recorded along with the presence of sclerotic lines and osteolysis. Results. Wear analysis: Using the average of the slopes of the individual regression lines, the wear rate was 0.006±0.033mm/yr. Using the early to latest film method, the wear rate was 0.003±0.056mm/yr. Radiographic analysis: Acetabular side: the greatest incidence of radiolucency occurred in zone 1 at 21%; sclerotic lines had a less than 2% incidence in any of the 3 zones; there was no identified osteolysis. Femoral side: the incidence of radiolucencies was limited to zone 1, 2%; sclerotic lines were rare in any zone, maximum in zone 3, 4%; there was no identified osteolysis. Conclusion. The wear of this form of irradiated and melted highly crosslinked polyethylene remained at levels lower than the detection limit of the software at minimum 13 year follow-up and there was no identified osteolysis

Manual postoperative CT calculation of anteversion and inclination of the acetabular cup can be inaccurate and depends on the observer's experience. The aim of this study is to describe and present a validation of a new CT-image-based dedicate software (EGIT) for calculation of the acetabular component placement. The software principle is based on a three-dimensional reconstruction of a patient's bones from anatomical data collected postoperatively on the patient's CT scan. 15 Patient to be operated for THR were enrolled in this study. All patients were evaluated with post operative CT-scan. Measurement of Cup positioning were performed with two different methods: a manual method, performed by an expert radiologist, and a software CT image based method. Statistical analysis was performed with Intraclass Correlation Coefficent to asses interobserver and intraobserver reliability. A paired T-test was used to detect differences between manual and software methods. The Intraclass Correlation Coefficient was excellent for both the intraobserver and interobserver reliability. As expected the ICC is higher in the interobserver case. A mean cup anteversion of 14.2 (S.D. ±6.9), mean inclination of 44.2 (S.D.± 5.8) are detected with EGIT by the expert surgeon; Mean Cup anteversion of 13.6 (S.D. ± 5.11), mean inclination of 43.3 (S.D.± 5.1) are detected with manual method by expert radiologist. No statistical difference have been found (P> 0.05). The EGIT software seems to be an easy, accurate and reproducible method to calculate acetabular cup positioning using standard post-operative CT scan in THA

Of 960 first-revision total hip replacements (THR) because of deep infection identified in the Swedish Hip Arthroplasty Registry, 16.9% were treated with a permanent implant extraction, while a staged or direct reconstruction revision protocol were employed in 56.2% and 26.9% respectively. The majority of the interventions were performed more than one year after index THR, and the dominating pathogen was coagulase negative staphylococci (CNS). We found a significant shift in types of bacteria over the years (Chi-square test, p smaller than 0.001): an increase in the CNS group and a decrease in Gram-negative aerobes. Patients treated with a permanent resection were generally older (p< 0.001), had more often a previous ipsilateral hip fracture (p< 0.001), and had more frequently Gram-negative infections (p=0.02). No systematic differences in patient characteristics or pathogens were detected between one-stage or two-stage procedures, of which the latter had a median re-implantation time of 2 (range: 0.2–62) months. Of 798 (one- or two-stage) revisions, 60 (7.5%) were revised again due to recurrent infection, with no difference between the two methods, and implying a 10-year survival of 90%; 95% confidence interval (CI95%) 88.2–93.0. Previous surgery for soft-tissue problems (RR 3.2 (CI95% 1.3–7.2)) predicted a worse outcome for one-stage procedures. The prognosis of two-staged revisions improved with increasing re-implantation interval (RR 0.8 (CI95% 0.7–1.0)) per month, and a 6 month interval carried the lowest risk of repeat revision due to infection; RR 0.1 (CI95% 0.0–0.9). Staged revisions in female patients (RR 2.3, (CI95% 0.9–5.7)) and with Staphylococcus aureus infections (RR 2.3 (CI95% 0.9–5.5)) predicted a worse outcome. Ten-year survival with repeat revision for aseptic loosening as end-point was 89% (95%CI 85.7–92.0), but decreased to 79% when all reasons for revision were taken into account (95%CI 75.0–82.3) mainly because of revision for peri-prosthetic fractures. The results suggest that direct and staged revision protocols can have a good prognosis on a national level, but efforts must be made to counteract periprosthetic fractures and the high incidence of permanent implant extraction in elderly patients

Introduction. Silicon nitride (SiN) is a recently introduced bearing material for THR that has shown potential in its bulk form and as a coating material on cobalt-chromium (CoCr) substrates. Previous studies have shown that SiN has low friction characteristics, low wear rates and high mechanical strength. Moreover, it has been shown to have osseointegration properties. However, there is limited evidence to support its biocompatibility as an implant material. The aim of this study was to investigate the responses of peripheral blood mononuclear cells (PBMNCs) isolated from healthy human volunteers and U937 human histiocytes (U937s) to SiN nanoparticles and CoCr wear particles. Methods. SiN nanopowder (<50nm, Sigma UK) and CoCr wear particles (nanoscale, generated in a multidirectional pin-on-plate reciprocator) were heat-treated for 4 h at 180°C and dispersed by sonication for 10 min prior to their use in cell culture experiments. Whole peripheral blood was collected from healthy donors (ethics approval BIOSCI 10–108, University of Leeds). The PBMNCs were isolated using Lymphoprep® as a density gradient medium and incubated for 24 h in 5% (v/v) CO2at 37°C to allow attachment of mononuclear phagocytes. SiN and CoCr particles were then added to the phagocytes at a volume concentration of 50 µm3 particles per cell and cultured for 24 h in RPMI-1640 culture medium in 5% (v/v) CO2 at 37°C. Cells alone were used as a negative control and lipopolysaccharide (LPS; 200ng/ml) was used as a positive control. Cell viability was measured after 24 h by ATPLite assay and tumour necrosis factor alpha (TNF-α) release was measured by sandwich ELISA. U937s were co-cultured with SiN and CoCr particles at doses of 0.05, 0.5, 5 and 50 µm3 particles per cell for 24h in 5% (v/v) CO2 at 37 C. Cells alone were used as a negative control and camptothecin (2 µg/ml) was used as a positive control. Cell viability was measured after 0, 1, 3, 6 and 9 days. Results from cell viability assays and TNF-α response were expressed as mean ±95% confidence limits and the data was analysed using one-way ANOVA and Tukey-Kramer post-hoc analysis. Results and Discussion. At a high volume concentration of particles (50µm3 per cell), SiN did not affect the viability of PBMNCs, while CoCr significantly reduced the viability over a 24 h period [Figure 1A]. Similarly, SiN particles had no effect on the viability of U937s up to 9 days with a range of particle doses (0.05–50 µm3 per cell) [Figure 2A]. In contrast, CoCr particles significantly reduced the viability of U937s after 6 days [Figure 2B]. Additionally, CoCr particles caused significantly elevated levels of pro-inflammatory cytokine TNF-α, whereas no inflammation was associated with SiN particles [Figure 1B]. Conclusion. This study has demonstrated the in-vitro biocompatibility of SiN nanoparticles. Therefore, SiN is a promising orthopaedic bearing material not only due to its suitable mechanical and tribological properties, but also due to its biocompatibility. Acknowledgements. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. GA-310477 LifeLongJoints

The purpose of this research is to propose CT-free cup orientator using tilt sensors without expensive point tracking devices in total hip replacement. In the case of using a mechanical guide, the accuracy of cup orientation can be sacrificed because of change of the patient’s posture during procedure. Several navigation systems have been introduced to secure an accurate position and orientation of the implant in THR. These systems are expensive and have some weakness due to possible interference inoptical measurement. Our orientator employs a T-bar shaped gauge and economic tilt sensors to secure a fairly orientation of acetabular cup inTHR. The T-bar gauge having three feet with adjustable distance is designed to obtain the anatomical landmarks concurrently. Each foot is placed on the anatomical landamark of the sawbone. The gauge has its own tilt sensor to identifiy the tilt angle of the guage using AD input board. Similary, the cup positioning tool and dynamic reference base (DRB) have their own tilt sensors. The experimental procedures of CT-free cup orientator are done as follows:. Place the T-bar gauge in right place on the pelvis by setting three feet on the ASIS and pubic. Attach DRB to pelvis and align its orientation parallel to the T-bargauge. Align the tilt sensor of the cup positioner parallel to DRB. We define errors as difference between experimental data and ground truth obtained by Micro-Scribe (Immersion Inc.) Errors of the cup in abduction and anteversion were 1.2 and 1.0 degrees respectively when the test is performed on a sawbone. We analyzed the causes of error to improve the accuracy of our cup orientator. Measuring landmarks and aligning three tilt sensors seemed to cause some errors. Base on this study, we expect to make an experiment on cadaver

Summary Statement. In young, active patients cementless THR demonstrates excellent prosthetic stability by RSA and outstanding clinical outcomes at 5 years using a tapered titanium femoral stem, crosslinked polyethylene liners and either titanium or tantalum shells. Introduction. Early femoral implant stability is essential to long-term success in total hip replacement. Radiostereometric analysis (RSA) provides precise measurements of micromotion of the stem relative to the femur that are otherwise not detectable by routine radiographs. This study characterised micromotion of a tapered, cementless femoral stem and tantalum porous-coated vs. titanium acetabular shells in combination with highly cross-linked UHMWPE or conventional polyethylene liners using radiostereometric analysis (RSA) for 5 years following THR. Patients and Methods. This IRB-approved, prospective, double randomised, blinded study, involved 46 patients receiving a primary THR by a single surgeon. Each patient was randomised to receive a titanium (23) (Trilogy, Zimmer) or tantalum (23) (Modular Tantalum shell, Zimmer) uncemented hemispheric shell and either a highly-crosslinked or conventional polyethylene liner. Tantalum RSA markers were implanted in each patient. All patients had a Dorr A or B femoral canal and received a cementless, porous-coated titanium tapered stem (M/L Taper, Zimmer). All final femoral broaches were stable to rotational and longitudinal stress. RSA examinations, Harris Hip, UCLA, WOMAC, SF-12 scores were obtained at 10 days, 6 months, and annually through 5 years. Results. All patients demonstrated statistically significant improvement in Harris Hip, WOMAC, and SF-12 PCS scores post-operatively. Evaluation of polyethylene wear demonstrated that median penetration measurements were significantly greater in the conventional compared to the HXPLE liner cohorts at 1 year through 5 years follow-up (p<0.003). At 5 years, conventional liners showed 0.38 ± 0.05mm vertical wear whereas HXLPE liners showed 0.08 ± 0.02mm (p<0.003). Evaluation of the femoral stems demonstrated that the rate of subsidence was highest in the first 6 months (0.09mm/yr), with no other detectable motion through 5 years. Two outlying patients had significantly higher stem subsidence values at 6 months (0.7 mm and 1.0mm). One stem stabilised without further subsidence after 6 months (0.7mm), and the other stem stabilised at 1 year (1.5mm). Neither patient has clinical evidence of loosening. Evaluation of acetabular shells demonstrated less median vertical translation in tantalum than titanium shells at each time-point except at 3-years follow-up, however due to large standard errors, there was no significant difference between the two designs (p>0.05). These large standard errors were predominantly caused by two outliers, neither of which had clinical evidence of loosening. Discussion/Conclusion. In this RSA study of young THR patients, cementless tapered femoral stems, highly crosslinked polyethylene liners, and tantalum or titanium acetabular shells all demonstrated excellent performance through 5 years follow-up. Highly crosslinked polyethylene liners demonstrated significantly less wear than conventional liners. The femoral stem showed excellent stability through 5 years, with no clinical or radiologic episodes of failure. The small amount of micromotion seen is less than that previously reported for similar tapered, cementless stems and approaches the accuracy of RSA (0.05mm). Both acetabular shells demonstrated excellent stability with minimal micromotion at 5 years without significant differences in migration. All patients demonstrated significant clinical improvement in pain and function and additional RSA evaluation of these patients is planned

This preliminary study concerns the results of THR using a minimally invasive computer assisted technique: We use the Siguier and Judet procedure. The patient is in supine position and we use an orthopedic table. The skin incision is 6 to 8 cm long and we dont cut any muscle during the approach. The first 30 cases are studied: The navigation system is scanner free and allows different controls: cup inclination and anteversion, center of rotation, laterality, lengh of the lower limb. The acetabular implant is a cementless impacted cup and the femoral implant is either cemented or cementless. The first results are rapported and the technical modifications are descreibed. A randomized study of 50 patients with CAS and 50 without CAS is now begining to determine if the risk of bad positionning the implants in MIS decreases when we use computer assisted surgery

This is a minimum 15 year follow up of a cohort of 58 patients (30 men and 28 women) who underwent 62 non-cemented THR between 1998–2000 (54 unilateral, 4 bilateral), in whom an off-the-shelf “lateral flare” femoral component was implanted. These surgeries were performed by a single surgeon and have been followed continuously by that same surgeon. The mean age at the time of surgery was 60.4 yrs (52–74). There were no exclusions for osteoporosis or type “C” femoral geometry. Although some patients have deceased during these 15 years, there have been no stem failures, revisions or impending stem revisions at the time of follow up or at the time of death in those who have passed. Two patients have undergone revision of their acetabular liner for poly wear. There have been no complaints of thigh pain; and like the results seen in other series employing this stem design, there has been no evidence of bone loss due to stress shielding or subsidence of the femoral component in any of these patients. This mid-term follow up re-affirms the dynamic tension band model of hip biomechanics, upon which the “lateral flare” design is predicated. This model predicts that the proximal lateral femur can experience compression during the gait cycle and as such can be utilized as an additional base of support upon which the femoral component can rest. Rather than relying upon a traditional “press fit” technique to achieve initial implant stability, a technique which is highly dependent upon femoral geometry, bone quality and may risk fracture on implant seating, the “lateral flare” design permits a gentler, safer and more physiologic means of achieving initial implant stability necessary for osseous integration to occur. This alterantive terchnique has been termed a “rest fit”

Introduction A review of hip replacements performed in our hospital between 1991 and 2000 has identified a group of post-operative patients in whom recurrent dislocation has been deemed untreatable because of medical comorbidity. We tried to identify a group of patients at risk of recurrent dislocations. This paper presents our experience with the Kasselt cup in these patients. Methods We have used the Kasselt cup with indications being: a) prophylaxis, in patients with perceived greater risk of recurrent dislocation and b) treatment of recurrent (three or more) dislocations following THR. Patients were identified from clinical records and a National Joint Register. From 1998 to 2002, 51 patients underwent THR utilizing semi-constrained Kasselt cup. All living patients were invited for clinical and radiographic examination. Forty-eight patients (51 hips) were available for study. Thirty-nine patients were able to attend clinic and nine were interviewed by telephone. Average follow-up was 18.6 months (range 6 to 36 months). Average age was 75.6 years (range 56 to 92 years). Twenty-nine operations were done prophylactically and 22 for recurrent dislocations. Results Three patients suffered further dislocations, from the recurrent dislocation group. One suffered a single dislocation post-operatively which was reduced by close manipulation and to-date has not re-dislocated. The second continued to dislocate. The third was revised with a Kasselt cup for recurrent dislocation and suffered three further dislocations. This patient was re-revised and to-date (six months) has had no further dislocation. The mean Harris Hip Score in the whole group was 79 (range 49 to 100). We have seen no dislocation in patients in the ‘at risk’ group in this short term. Conclusion The value of this prosthesis remains uncertain

The timing of total hip replacement (THR) in patients with active tuberculosis (TB) of the hip is controversial, because of the potential risk of reactivation of infection. There is little information about the outcome of THR in these patients. We conducted a systematic review of published studies that evaluated the outcome of THR in patients with active TB of the hip. A review of multiple databases referenced articles published between 1950 and 2012. A total of six articles were identified, comprising 65 patients. TB was confirmed histologically in all patients. The mean follow-up was 53.2 months (24 to 108). Antituberculosis treatment continued post-operatively for between six and 15 months, after debridement and THR. One non-compliant patient had reactivation of infection. At the final follow-up the mean Harris hip score was 91.7 (56 to 98). We conclude that THR in patients with active TB of the hip is a safe procedure, providing symptomatic relief and functional improvement if undertaken in association with extensive debridement and appropriate antituberculosis treatment. Cite this article: Bone Joint J 2013;95-B:578–82

Total hip replacement (THR) has been shown to be a cost-effective procedure. However, it is not risk-free. Certain conditions, such as diabetes mellitus, are thought to increase the risk of complications. In this study we have evaluated the prevalence of diabetes mellitus in patients undergoing THR and the associated risk of adverse operative outcomes. A meta-analysis and systematic review were conducted according to the guidelines of the meta-analysis of observational studies in epidemiology. Inclusion criteria were observational studies reporting the prevalence of diabetes in the study population, accompanied by reports of at least one of the following outcomes: venous thromboembolic events; acute coronary events; infections of the urinary tract, lower respiratory tract or surgical site; or requirement for revision arthroplasty. Altman and Bland’s methods were used to calculate differences in relative risks. The prevalence of diabetes mellitus was found to be 5.0% among patients undergoing THR, and was associated with an increased risk of established surgical site infection (odds ratio (OR) 2.04 (95% confidence interval (CI) 1.52 to 2.76)), urinary infection (OR 1.43 (95% CI 1.33 to 1.55)) and lower respiratory tract infections (OR 1.95 (95% CI 1.61 to 2.26)). Diabetes mellitus is a relatively common comorbidity encountered in THR. Diabetic patients have a higher rate of developing both surgical site and non-surgical site infections following THR. Cite this article: Bone Joint J 2013;95-B:1474–9

This presentation introduces a new tool to be used in the cementing of acetabular components in total hip arthroplasty, the ‘Rim Cutter’. The Rim Cutter is designed to cut a ledge in the rim of the acetabulum into which a flanged cup can be cemented. The flange is trimmed such that it fits precisely into the ledge cut in the acetabulum. We present the in vitro pilot study of the effect of using this tool on the intra-acetabular cement mantle pressure during cup insertion and also the effect on the depth of cement penetration as the cup is inserted. A significant improvement in both cement pressure and cement penetration over conventional flanged and unflanged cups is noted. Improved cement penetration around the rim of the acetabulum in THR has implications for reducing the rate of aseptic loosening. The pilot study also suggests other beneficial features of using the rim cutter such as improved cup centralisation, control of orientation and the prevention of the cup ‘bottoming out’. Further in vivo studies are required to better assess its efficacy

Component migration after THR is directly correlated with loosening and reported to be predictive for the long-term survival rate. In literature, four different patterns of stem-migration are reported. Likewise, periprothetic osteolytic zones indicate the risk of loosening and revision in the further course. Nevertheless, little is known about the distinguish migration behaviour between cemented and uncemented stems throughout the process of loosening. The aim of this study was to evaluate the influence of cementing on migration behaviour of loose femoral components after THR. A total of 207 stem-revisions have been performed at our institution between 1996 and 2001. Only patients with aseptic loosening after primary hip replacements were included in the present study. Thus, 75 patients had to be excluded due to other reasons for loosening. Migration analysis was done with the EBRA-FCA method (Einzel-Bild-Röntgen-Analyse, Femoral Component Analysis). In addition, a radiographic analysis was performed following Gruen et al. For migration analysis, a minimum of four x-rays per series are required. Hence, another 72 patients had to be excluded due to insufficient x-ray documentation. A total of 40 cemented (Group A) and 20 uncemented (Group B) femoral components could be analysed. There were no significant differences between the two groups with regard to age (60 years for Group A, 56 years for Group B), gender or side. Mean number of radiographs per series was 7.2 for Group A and 7.9 for Group B respectively. Mean stem survival differed between the two groups (11.3 years for Group A and 8.8 years for Group B), but without statistical significance (T-Test: p> 0.05). Differences in migration behaviour and distinct types of loosening after cemented and uncemented total hip replacement will be presented

The current decade has seen a marked rise in popularity of minimally invasive hip replacement, done through a variety of surgical approaches. A specific downside to the direct anterior approach includes the significant difficulty getting a “straight shot” down the femoral canal for either straight, nonflexible reaming or broaching as with standard approaches. Improper alignment in the femoral canal can lead to sub-optimal load transfer and thus compromised fixation. The femoral broach and stem insertion path for this approach is best described as a curved one, rather than the typical straight path. Some femoral components appear to be more suitable to this technique due to their geometries. The purpose of the study was to describe the effects that the single geometric parameter, stem length, has on its insertion path into the femoral canal. Due to the potential introduction of human error associated with repetitively performing a specific motion, both a physical study and a computer generated analysis were conducted. For the physical portion of the study, a femoral implant body of generic fit and fill geometry was designed and manufactured. The length of the stem was varied from 40 mm to 100 mm in 10 mm increments. A medium sized synthetic femur (Sawbones, Pacific Labs, Seattle, WA) was machined to match the volume of the full length stem. The insertion path constraints were defined such that the stem had to maintain the greatest allowable insertion angle while still making contact on both the medial and lateral side of the canal during translation in the X direction. To reduce the variability in applying the constraints, a single author conducted the insertion procedure for each length stem while the path was videotaped from a fixed position directly in front of the setup. The most proximal lateral point of the stem was tracked through the insertion path and the X, Y coordinates were recorded at a frequency of 2 FPS. The area under this curve, referred to as the minimum insertion area (MIA), was calculated. For the computer generated portion of the study, a CAD model of the standard length Omnifit. ®. (Stryker Orthopaedics) was utilized. The stem was modified to create 5 additional models where the length was progressively shortened to 65%, 55%, 45%, 35%, and 25% of original length or 91mm, 77mm, 63mm, 49mm, and 35mm respectively. The femur was created from a solidified mesh of a computed tomography (CT) scan with the canal virtually broached for a full length stem. The models were each virtually assembled within the femoral canal with the similar constraints as the physical study. Again, the most proximal lateral point of the stem was tracked through the insertion path with the coordinates recorded and the MIA was calculated. There was a non-linear relationship between stem length and the MIA with the rate of change decreasing as the stem length decreased. That is, the greatest decrease in MIA was between the standard length and next longest length in the computer simulation. It was noted that marked change in MIA began to subside between the 77mm and 63mm stems and continued this trend of having less influence onward through to the shorter lengths. Although the results of the physical study showed a higher variability than the computer generated portion, it does confirm the results of the computer generated study. Minimizing the trauma associated with THR has led most of the above authors to the direct anterior approach. However, the femoral broach and stem insertion path is best described as a curved one, rather than the typical straight path used in other approaches. This curved insertion path also has benefits for other approaches since the broaches and stem can be kept away from the abductors, minimizing the potential injury to them. Shorter stem length makes this curved insertion path easier to perform. This is the first study to describe the effect that stem length has on its insertion path into the femoral canal. As expected, the physical portion of the study showed more variability than the computer generated portion. However, the physical and computer studies correlated well, with shorter stem lengths clearly allowing a more curved insertion path. The improvement tapered off in stem lengths below 63mm. This length correlates well with the other attempts at a shorter stem. This study provides quantitative data to help with shorter stem design and possible computer navigated insertion paths

Introduction: Patients who develop proximal femoral growth arrest present a typical deformity of short femoral neck, high riding greater trochanter, and caput valgum. This is seen usually seen in Perthes, AVN due to treatment of CDH, and sometimes in epiphyseal dysplasia. Method: We present a series of 34 cases (34 hips) treated at the above institutes. The cases treated in Berne were prior to 2002. Twenty patients were females. There were 24 patients with Perthes, nine with old healed and treated DDH, and one with epipyhseal dysplasia. All had Trendelenburg or delayed Trendelenburg sign. They had an average shortening of 3.5 cms, and their age range was 14 yrs to 64 yrs. Pre-op assessement was done with plain radiographs, CT scan, and or MRI scan. Results: Their Merle D’Aubigne score improved from 13 (10 to 15) to 17 (15 to 18) at the latest follow up. Twenty four (70%) had good to excellent result. Five have since undergone a total hip replacement, and five have some pain but can do reasonable amount of activity. The follow-up is 6 years (2 to 13 years). There was one trochanteric non-union, but no cases of AVN. Discussion: We describe the technique of biomechanically improving the moment arm and muscle length with this procedure. This helps the soft tissues to strengthen, improve force vectors in the correct direct in the hip, perhaps improve the longevity of the joint and also prepare the hip soft tissues for future THR

Introduction: Wear, and the resultant loosening and revision, of Total Hip Replacements (THRs) remains the limiting factor in the long term success of the prosthesis. Over 1 million Total Hip Replacements (THRs) are implanted each year, of which about 15% are revisions, most of which are a consequence of loosening of either femoral or acetabular components. This is frequently caused by either the mechanical (. Wroblewski, 1986. ) or biological (. Besong et al, 1997. ) response to the wear of ultra-high molecular weight polyethylene (UHMWPE) acetabular component. In a previous study . Bennett (2002. , . 2000. ) has demonstrated that the walking patterns of THR patients 5 years post operation directly correlated with the wear of the acetabular component, as measured radiographically. The present study considers THR patients 10 years post-operatively, ensuring more accurate wear measurements and more meaningful outcome measures. Materials and Methods: Gait Analysis was performed on a number of THR patients following routine review using a Vicon 370 data capture system and a lower body marker set. This data was processed using Polygon software and joint angles were derived for the hip in the sagittal, coronal and transverse planes. A computer simulation was used to determine the path which each of 20 points on the prosthetic femoral head traces on the acetabulum during walking. Results: It was found that patients exhibited different patterns of movement ranging from liner to multi-directional. Normal subjects have previously been found to exhibit multi-directional movement. Patients with mult-directional movement showed evidence of greater wear (. Bennett et al., 2000. ). Discussion and conclusion: Linear movement causes orientation hardening and wear resistance while multi-directional movement cause increased shear and greater wear rates. These differences in movement loci have a significant influence on UHMWPE wear rate and the long term survival of the implant

Introduction:. Total Hip Replacement (THR) is a proven and effective surgical procedure. One of the main limiting factors of the longevity of THR is the performance of the bearing surface. The optimum bearing surface choice, however, remains controversial. We wanted to understand what influenced the choice of bearing surfaces amongst South African orthopaedic surgeons. We also wanted to know if there was any consensus between surgeons and the orthopaedic trade. Aims, material and methods:. There is no epidemiological registry-based data available in South Africa in respect of bearing surfaces used in hip replacements. We sent out an electronic survey to all members of the South African Orthopaedic Association as well as to trade representatives. Patient parameters influencing the choice of bearing surfaces were surveyed and these included age, gender, level of activity and diagnosis. We used a regressional and tree analysis methodology to interpret the results. Results:. We received 133 responses from orthopaedic surgeons. There were no differences in decision making and bearing surface choices according to the surgeon's experience, type of practice or fellowship training. It was statistically significant that age was the first and most important factor when deciding upon a bearing surface. The patient's activity level then played a secondary role in the final choice. We show that gender and clinical diagnosis played no significant part in decision-making. Ceramic-on-ceramic combinations were used most commonly in younger patients and metal-on-polyethylene in older patients. 73% of surgeons chose metal-on-polyethylene in patients older than 70 years. There were no surgeons who selected metal-on-metal or ceramic-on-metal combinations for any patients. Metal-on-polyethylene was the first choice in 51% of patients with a low-activity level and 23% of those patients with a high level of activity. Ceramic-on-ceramic and ceramic-on-polyethylene was the first choice in patients with a high level of activity by 32% and 34% of surgeons respectively. We received 51 responses from the trade representatives surveyed. There was no difference between the surgeons and the trade representatives in respect of their decision making when advising on bearing surfaces to be used in specific patients. Conclusion:. While each bearing surface combination has advantages and disadvantages we have demonstrated the rationale behind the decision making and the current trends in choices of bearing surfaces by South African orthopaedic surgeons. We note that our surgeon's choices are in line with international trends, especially in respect of metal containing bearing surfaces. We have also shown that the orthopaedic trade representative's guidelines are in keeping with those of the profession

There is little in the literature on the level of participation in sports which patients undertake after total hip replacement (THR). Our aims in this study were to determine first, the level of sporting activity, second, the predictive factors for returning to sporting activity, and third, the correlation between participation in sports and satisfaction after THR. We retrospectively identified 815 patients who had undergone THR between 1995 and 2005. All were asked to complete a self-administered questionnaire regarding their sporting activity. A total of 571 patients (71%) met the inclusion criteria and completed the evaluation. At a mean follow-up of 9.8 years (. sd. 2.9), 366 patients (64%) returned to sporting activity as defined by a University of California at Los Angeles (UCLA) score of > 5. The main reasons that patients had for refraining from sports were fear of dislocation (65; 31.6%), avoiding wear (52; 25.4%), and the recommendation of the surgeon (34; 16.6%). There was a significant relationship between higher post-operative participation in sport in those patients with a higher pre-operative Harris hip score (HHS) (p = 0.0074), motivation to participate in sporting activities (p = 0.00022) and a shorter duration of symptoms (p = 0.0034). Finally, there was a correlation between age (p = 0.00013), UCLA score (p = 0.012) and pre-operative HHS (p = 0.00091) and satisfaction. In conclusion, we found that most patients participate in sporting activity after THR, regardless of the advice of their surgeon, and that there is a correlation between the level of participation and pre-operative function, motivation, duration of symptoms and post-operative satisfaction. Cite this article: Bone Joint J 2014;96-B:1041–6

Total hip replacement (THR) after acetabular fracture presents unique challenges to the orthopaedic surgeon. The majority of patients can be treated with a standard THR, resulting in a very reasonable outcome. Technical challenges however include infection, residual pelvic deformity, acetabular bone loss with ununited fractures, osteonecrosis of bone fragments, retained metalwork, heterotopic ossification, dealing with the sciatic nerve, and the difficulties of obtaining long-term acetabular component fixation. Indications for an acute THR include young patients with both femoral head and acetabular involvement with severe comminution that cannot be reconstructed, and the elderly, with severe bony comminution. The outcomes of THR for established post-traumatic arthritis include excellent pain relief and functional improvements. The use of modern implants and alternative bearing surfaces should improve outcomes further. Cite this article: Bone Joint J 2013;95-B, Supple A:11–16

United Kingdom National Institute for Health and Clinical Excellence guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractures of the femoral neck in cognitively intact patients, who were independently mobile prior to the injury. This study aimed to analyse the risk factors associated with revision of the implant and mortality following THR, and to quantify risk. National Joint Registry data recording a THR performed for acute fracture of the femoral neck between 2003 and 2010 were analysed. Cox proportional hazards models were used to investigate the extent to which risk of revision was related to specific covariates. Multivariable logistic regression was used to analyse factors affecting peri-operative mortality (< 90 days). A total of 4323 procedures were studied. There were 80 patients who had undergone revision surgery at the time of censoring (five-year revision rate 3.25%, 95% confidence interval 2.44 to 4.07) and 137 patients (3.2%) patients died within 90 days. After adjusting for patient and surgeon characteristics, an increased risk of revision was associated with the use of cementless prostheses compared with cemented (hazard ratio (HR) 1.33, p = 0.021). Revision was independent of bearing surface and head size. The risk of mortality within 90 days was significantly increased with higher American Society of Anesthesiologists (ASA) grade (grade 3: odds ratio (OR) 4.04, p < 0.001; grade 4/5: OR 20.26, p < 0.001; both compared with grades 1/2) and older age (≥ 75 years: OR 1.65, p = 0.025), but reduced over the study period (9% relative risk reduction per year). THR is a good option in patients aged < 75 years and with ASA 1/2. Cementation of the femoral component does not adversely affect peri-operative mortality but improves survival of the implant in the mid-term when compared with cementless femoral components. There are no benefits of using head sizes > 28 mm or bearings other than metal-on-polyethylene. More research is required to determine the benefits of THR over hemiarthroplasty in older patients and those with ASA grades > 2

Introduction: Patient specific cementless femoral components for THR were developed as a means of addressing the anatomic variations of the proximal femur and hip joint in an effort to achieve long term implant survival and optimum patient function. Design rules were developed with goals of achieving rigid initial stability, maximal endosteal contact for bone integration, and the precise restoration of hip kinematics. Methods: Beginning in 1989, this series of cementless titanium implants included proximal circumferential HA coating over a macrotextured surface for biologic fixation. All patients who were candidates for cementless arthroplasty (age < 65, active, or overweight) received a custom femoral component. Forty-nine consecutive primary THR in 39 patients were performed during the study period. No patients died and one patient was lost prior to 10 years; all had well fixed stems at latest follow up. The remaining 38 patients (48 hips), 16 females and 22 males, with average age 54 (28-70) and weight 181 (98-270) at surgery, were evaluated at minimum 10 years (range 10-11). Results: Average modified Harris Hip Scores were 49 (27-87) pre- and 89 (24-100) postoperatively, with pain scores of 17 (0-40) and 42 (10-44) respectively. All femoral components remain well-fixed (Engh Class 1) at final follow-up. No areas of osteolysis were seen distal to the proximal HA-bone interface. Small, focal areas of probable osteolysis were seen at the implant shoulder (4 cases), at the calcar corner (2 cases), and at both sites (1 case). Complications included four proximal margin femoral fissures recognised at surgery, two patients with dislocation, and one non-fatal PE. Reoperations included six head and liner exchanges; two for recurrent dislocation, and four for excessive wear with associated osteolysis (3 pelvic, 1 femoral); and one for fixation and grafting of a trochanteric nonunion. Discussion: The use of cementless femoral implants based on individual patient characteristics and a set of strict design rules has resulted in excellent clinical and radiographic results at 10-year follow-up. Recent data with some OTS systems have shown comparable excellent results and have diminished the need for the routine use of custom implants in uncomplicated primary situations. However, this series validates the design concepts of this system, supports its use in more complex situations, and suggests applicability on a routine basis where other available implants may be less than optimal

Rivaroxiban is a factor Xa inhibitor and is a newer oral alternative for thromboprophylaxis after joint replacements. Its major advantage is its oral administration and hence better patient compliance. However there are some doubts about its efficacy compared to dalteparin/heparin. We have recently changed over from using dalteparin injections to rivaroxiban tablets for thromboprophylaxis after hip replacements. We assessed our results to find efficacy and specificity of its action in patients undergoing THR. 504 patients underwent hip replacement in last 2 years. 316 were treated with dalteparin injections (fragmin) for thromboprophylaxis while 189 patients were treated with oral rivaroxiban for 35 days after their hip replacement. Average haemoglobin drop at 24 hours postop was 2.79 in Rivaroxiban group compared to 3. 10 in dalteparin group. 19 patients (of 189 i.e. 10.05%) required postop blood transfusion in rivaroxiban group as against 60 (of 315 i.e. 19.04%) in Dalteparin group. This difference was statistically significant. Incidence of DVT was no different in either groups, but the number of patients was too small to compare this. Rivaroxiban appears to be more specific in its action and our results suggest a significant reduction in postop blood transfusion following hip replacements without any increase in rate of Deep Vein Thrombosis. We would like to present our findings and discuss role of oral thromboprophylaxis after joint replacements

The new technology using femoral heads with sleeves allows conservative procedures for revision hip arthroplasty. The implantation of classical ceramic heads on a previously used femoral taper is not recommanded. When there is no loosening of the femoral implant, the use of sleeves is a good solution for using an alumine on alumine couple, specially in young and active patients. Material and methods: 25 hips in 25 patients were included. In 12 cases the cause of revision was an acetabular osteolysis with or without loosening in metal on metal cimented THR. In 13 patients the revision was performed for a loosening and a wear of the PHE cup with osteolysis (4 zyrcon and 9 chrome-cobalt heads). The mean age was 49 years for the metal on metal revisions (36 to 75) and 54 years for the prosthesis using a polyethylen socket. Cementless cups were implanted using XLW delta alumina inserts. The 32 mm delta alumina sleeved heads were adjusted on the existing femoral 12–14 tapers. Patients were evaluated preoperatively and followed-up with clinical and radiological examinations. Results: At 2 years mean follow-up, average Harris Hip Score was significantly improved (97 vs 54, p< 0.05). We did not observe ceramic fracture or squeaking. The radiographic results did not demonstrate acetabular loosening, osteolysis, or femoral abnormalities. Concerning the metal on metal revisions, the aseptic loosening of the socket was combined with high rates of cobalt and chromium serum levels. Mean delay before revision was 4 years (2 to 11). Unipolar acetabular revisions were only decided after a carefull inspection of the remaining stems to detect any taper alteration or impingement lesions. Postoperative cobalt and chromium serum levels significantly decreased postoperatively. Concerning the metal on PHE and the zyrcon on PHE revisions, the mean delay before revison was 11 years (4 to 21). At this short follow up, we did not notice any parasitic impingement due to the additional sleeve or any ceramic fracture or squeaking. The radiographic results did not demonstrate acetabular loosening, osteolysis, or femoral abnormalities. Discussion: Failures of metal-on-metal or metal on PHE hip arthroplasties raise new technical problems. Conversion to ceramic on ceramic has been suggested in case of hypersensibility reactions or high rate of serum metal ions, and in case of osteolysis in young population. This prospective study evaluates a revision strategy using ceramic cups and delta ceramic heads with titanium adapter sleeves when a femoral revision is not required. Despite the limitation due to short follow-up, this technical option should be considered when wear surfaces exchange is decided

This is a report on the first 100 THR patients treated with an off the shelf version of a novel “Lateral Flare” femoral component. A prior published report has documented the up to 19 year follow up of custom fabricated stems of an identical design concept as being successful in patients < 55 years of age. HHS, radiographic measure of bone morphology, implant stability and densitometric measure of bone response after THR with an off the shelf version, “Revelation Lateral Flare”, femoral component, confirm excellent bone preservation and implant stability with this design concept. DEXA analysis of a 20 consecutive patient subset of these 100 patients, documented preservation of more than 95% of proximal femoral bone stock in Gruen zone 1 and 102% of total bone stock in Gruen zones 1–7. Implant stability measurement documented < 0.5mm of subsidence in spite of patients being permitted immediate post-operative full weight bearing activity. These findings support reasonable optimism for expectation of successful long term results being achievable with the use of an off the shelf version of the “Lateral Flare” design concept, in young, high demand patients suffering with early onset osteoarthrosis of the hip

Pre-operative planning for total hip replacement (THR) is challenging in hips with severe acetabular deformities, including those with a hypoplastic acetabulum or severe defects and in the presence of arthrodesis or ankylosis. We evaluated whether a Rapid Prototype (RP) model, which is a life-sized reproduction based on three-dimensional CT scans, can determine the feasibility of THR and provide information about the size and position of the acetabular component in severe acetabular deformities. THR was planned using an RP model in 21 complex hips in five men (five hips) and 16 women (16 hips) with a mean age of 47.7 years (24 to 70) at operation. An acetabular component was implanted successfully and THR completed in all hips. The acetabular component used was within 2 mm of the predicted size in 17 hips (80.9%). All of the acetabular components and femoral stems had radiological evidence of bone ingrowth and stability at the final follow-up, without any detectable wear or peri-prosthetic osteolysis. The RP model allowed a simulated procedure pre-operatively and was helpful in determining the feasibility of THR pre-operatively, and to decide on implant type, size and position in complex THRs. Cite this article: Bone Joint J 2013;95-B:1458–63

Introduction: Historically, it has been accepted that the pain associated with arthritis of the hip is usually located in the groin, anterior and lateral thigh with occasional radiation to the anterior knee. Patients complaining of thigh pain that extends below the knee are often considered to have a degenerative lumbar spine as the cause for their lower limb symptoms and total hip replacement (THR) may not be offered. Following review of data regarding the preoperative distribution of pain in 2000 patients attending for hip replacement, it was noted that 40% of these patients had complained of pain at or below the knee. We proposed to prospectively investigate the severity and location of pain in patients attending for THR and assessed how this distribution of pain altered following surgery. We also proposed to examine the distribution of radiological wear preoperatively and assess if there is any relationship between localisation of pain, and the severity or distribution of the radiological wear pattern. Methods: 200 consecutive patients undergoing primary THR completed a questionnaire regarding the location and severity of their pain. Pain was localised to one or more of nine areas extending from low back to the foot. The localisation of pain was quantified as to severity using a visual analogue score. Questionnaires were completed both 4 weeks preoperatively and subsequently at a 3-month review clinic. All patients underwent a standardised preoperative AP and Lateral x-ray. The AP film was divided into three areas, and the lateral film was divided into 5 areas. Each zone was assessed as to the severity of wear pattern and graded from 1–3 (no change in joint space, decreased joint space, femoral or acetabular destruction). Results: The 200 patients complained of pain in a total of 980 areas preoperatively and 105 areas postoperative. 70% of the patients had complete relief of all pain at 3 months. The most common area of pain identified by patients was to the anterior aspect of the knee (82%), followed by pain at the greater trochanter and groin. 55% patients complained of pain extending to below the knee, mostly over the anterolateral aspect of the leg. Only 7% of these patients continued to complain of any below knee pain postoperatively, and all of these patients still had some relief of their below knee pain at review. With regard to the frequencies and severity of x-ray changes, zone-1 (34%) was most commonly severely damaged with femoral and/or acetabular destruction in the AP film, with the anterior and anterolateral areas being most commonly affected areas in the lateral film (20% and 19% respectively). When the distributions and severities of x-ray changes were correlated with the distribution of pain localised pre and postoperatively we were unable to show any association between the degree of radiological wear in any one zone and the locatin of pain identified by the patient. In fact, there was a normal distribution to the severity of radiological damage between each of the zones and localisation of pain in any of the 9 areas. Conclusions: A significant number of patients who require hip arthroplasty have pain extending below the knee. This pain is frequently relieved following THR. The commonest area of sever hip joint wear with loss of femoral or acetabular bone is antero-superiorly. It is important to recognise this during surgery, such that action can be taken to ensure appropriate reaming such that subsequent correct tissue tension and leg lengths are achieved. We are unable to show any relationship between area of pain and area of radiological degeneration. We believe that patients who complain of pain in their back, buttock or thigh, which extends below the knee, can still benefit from total hip replacement. Patients who attend complaining of low back pain with radiation of pain down their leg should have their hips as well as their lumbar spine examined and imaged. Careful consideration should be taken before labelling the paid as being referred from degenerative back disease

Introduction. Many tests have been published which measure frictional torque [1–4] in THR. However, different test procedures were used in those studies. The purpose of this study was to determine the effect of test setup on the measured friction torque values. Methods. Specimen Description Table 1 lists tested study groups (n≥3). Metal-on-Metal specimens were custom designed and manufactured, and are not approved for clinical use. The remaining groups consisted of commercially available products (Stryker Orthopaedics, NJ). Test Model – A. A 50 mm outer diameter (OD), Solid-Back Trident PSL shell (Stryker Orthopaedics, NJ) was assembled into a test block and the Ti6Al4V trunnion was oriented parallel to the central axis of the articulating surface [Fig. 1]. A 2450N axial load was applied. The head underwent angular displacement of ± 20° about the central axis of the shell. Test Model – B. The same shell and block as in Test Model A were used but positioned to simulate a 50° abduction angle [Fig. 1]. A Ti6Al4V trunnion was oriented to simulate a 130° neck angle. A 2450N side load was applied and the head underwent angular displacement of ± 20° about the central axis of the shell. Test Model – C. A 54 mm OD, Solid-Back Trident PSL shell was assembled into a hip simulator and oriented with a 50° abduction angle [Fig. 1]. The head was assembled onto a stainless steel trunnion and oriented with a 130° neck angle. The load was held at 2450N and the shell underwent a ± 23° biaxial rocking motion. All tests were conducted in a lubricated environment, using 25% bovine serum. Test Models A & B yielded a maximum static torque that was defined as the peak torque observed when the velocity of the femoral head approaches zero and the head changes direction. Test Model C exhibits continuous motion and yielded a maximum dynamic torque value. Test models were statistically compared using a single-factor ANOVA test and a Tukey post-hoc test at 95% confidence level. Results. Sample group results, see Table 2, were compared between test models and it was found each model yielded significantly different (p < 0.05) values. Except for the 28 mm-SXL group where there was no significant difference between test models A & C. Discussion. Each test method yielded unique results, as highlighted by the large difference seen between static and dynamic torque values given by test models B and C. Although, test model B yielded significantly greater static torque, further analysis of raw data indicated equivalent dynamic torque values when compared to model C. Additionally, the test methods did not consistently rank test groups. Two of the three tests showed similar torques when comparing the conventional and SXL materials, while the third model found a significant difference between the two groups. Results demonstrate that careful attention must be applied when selecting a test model

With greater numbers of younger patients undergoing total hip replacement (THR), the effect of patient age on the diameter of the femoral canal may become more relevant. This study aimed to investigate the relationship between the diameter of the diaphysis of the femoral canal with increasing age in a large number of patients who underwent THR. A total of 1685 patients scheduled for THR had their femoral dimensions recorded from calibrated radiographs. There were 736 males and 949 females with mean ages of 67.1 years (34 to 92) and 70.2 years (29 to 92), respectively. The mean diameter of the femoral canal was 13.3 mm (8.0 to 23.0) for males and 12.7 mm (6.0 to 26.0) for females. There was a poor correlation between age and the diameter of the canal in males (r = 0.071, p = 0.05) but a stronger correlation in females (r = 0.31, p < 0.001). The diameter of the femoral canal diameter of a female patient undergoing THR could be predicted to increase by 3.2 mm between the ages of 40 and 80 years, in contrast a male would be expected to experience only a 0.6 mm increase during the same period. This increase in the diameter of the canal with age might affect the long-term survival of the femoral component in female patients. Cite this article: Bone Joint J 2013;95-B:339–42

Studies of patients having primary THR using highly cross-linked polyethylene show excellent clinical outcomes and very low radiographic wear results at a minimum of 5 years follow-up. Recently, a radiostereometric analysis (RSA) study of a small group of patients reported that after no detectable wear during years 1–5, they found a significant increase in femoral head penetration between 5 and 7 years follow-up. However, this increase in head penetration after 5 years has not been confirmed in a larger patient cohort. The purpose of this study was to organize a multicenter radiographic study involving leading medical centers in the U.S. having the longest-term follow-up available on this type of highly cross-linked polyethylene in order to determine if the RSA observation can be confirmed in a larger study. Six academic centers agreed to contribute radiographic data to this study. All patients received primary total hip replacements with Longevity polyethylene liners (Zimmer, Warsaw, IN) coupled with 26, 28, and 32mm cobalt chrome femoral heads. The radiographic inclusion criteria required a minimum of four radiographs per patient: one at 1 year; at least one from 2 to 4.5 years; one 4.5 to 5.5 years; and at least one from 5.5 to 9 years follow-up. The Martell Hip Analysis Suit-eTM software was used for the wear analysis. All wear values were determined by calculating head penetration between the follow-up radiograph and the 1-year radiograph to remove creep, the majority of which has been shown to occur during the first year. Separate linear regressions, representing the wear rates, were computed for the early period from 1 year to 5.5 years and the late period from 5.5 years to 9 years follow-up. The Zar test was used to determine the significance of the difference between these two linear regressions. We present the completed analysis of 165 hips. When the early and late data points were combined into one data set, the second-order regression indicated an inflection point at 6.3 years with a slightly positive inflection. There were 402 film comparisons in the early time period, and the slope and confidence interval of the regression line was 4.9μm/yr (95% CI of −28μm/yr to 38μm/yr). There were 188 film comparisons in the late period, and slope of the regression line for the late period was 10.8 μm/yr (95% CI of −58μm/yr to 80μm/yr). The Zar test showed no significant difference between the two slopes (Figure 1, p=0.886). No significant increase in femoral head penetration was found for the late period after 5 years compared to the early period before 5 years follow-up in either analysis. Additionally, no significant late increase in wear was seen within individuals. While we continue to enroll patients, at this time we do not observe the increase in wear seen in the RSA study after 5 years

Introduction This study reviews the mid to long term results of revision THR with cemented, collarless double-tapered (CCDT) stems. Methods We prospectively studied 192 revisions, in 183 patients, of femoral stems using standard (42%) or long (58%) Exeter and CPT CCDT stems. Results were analysed according to the length of stem, extent of pre-operative deficiency (Paprosky I:II:IIIa:IIIb:IV = 4:20:44:20:12%) and intra-operative bone loss. Postoperative radiographs were independently analysed for loosening and stress shielding. Risk factors of poor outcome were examined by multivariate logistic regression. The median follow-up was six years (2 to 17 years) with 55 patients having died (28%) and no cases lost to follow-up. Results There were four stem re-revisions for sepsis (2%), three for aseptic loosening (1.5%) and three for component malpositioning (1.5%). The survivorship to femoral re-revision for aseptic loosening at eight years was 95% (95%CI=90–100%) for standard and 95% (90 – 100%) for long stems (p=0.674). Migration was less than five millimetre in unrevised stems. Survivorship and outcomes was independent of the Paprosky grade. There was a trend for better longer-term results in hips with long stems. Major stress shielding was not seen and thigh pain was not a problem. Conclusions CCDT long stems are suitable for most femoral revisions in patients without severe segmental deficiency. In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source

Introduction and Aims: The purpose of the present study was to review the early results and clinical performance of FDA approved large unipolar heads (36mm and greater) used with a metal-on-metal (MM) bearing. Method: Fourteen stem type prostheses were implanted in 14 patients. There were eight primary THA, and six conversions of surface arthroplasties in which thin-walled (5mm) porous coated MM sockets were maintained. Mean age was 55.4 years (range 30–72 years). There were nine males and five females. Dislocation precautions were discontinued after capsular healing (six weeks). The initial etiology was OA in 78%. Results: The median head size was 44mm (36–52) and socket size 54mm. Mean follow-up time was 29.1 months (range 12–81). UCLA hip scores improved for pain, walking, function, and activity from 4.8, 6.2, 6.1, and 4.8 pre-operatively to 9.3, 8.5, 7.5, and 5.4 postoperatively. Range of motion normalised. There were no complications. Conclusion: This investigation shows excellent clinical results, and suggests that dislocation can be avoided by an anatomical THR with the use of large unipolar femoral heads and thin sockets with low wear bearings. The advantage of MM is the ability to manufacture thin shells with porous beads for fixation and preserve ace-tabular bone stock

We have used total hip replacement combined with cemented intramedullary nailing to treat a selected group of nine patients with pathological fractures of the proximal femur and impending fractures of the shaft due to metastases. One patient died from cardiopulmonary failure on the third postoperative day, but the others were able to walk within the first week after operation. Complications included one recurrent dislocation of the THR and one fracture of an osteolytic lesion of the femoral shaft during nail insertion. Both were managed successfully. The hybrid osteosynthesis which we describe is an alternative to the use of tumour or long-stem prostheses; it has the advantage of preserving bone stock and muscle attachments

Objectives. To define Patient Acceptable Symptom State (PASS) thresholds for the Oxford hip score (OHS) and Oxford knee score (OKS) at mid-term follow-up. Methods. In a prospective multicentre cohort study, OHS and OKS were collected at a mean follow-up of three years (1.5 to 6.0), combined with a numeric rating scale (NRS) for satisfaction and an external validation question assessing the patient’s willingness to undergo surgery again. A total of 550 patients underwent total hip replacement (THR) and 367 underwent total knee replacement (TKR). Results. Receiver operating characteristic (ROC) curves identified a PASS threshold of 42 for the OHS after THR and 37 for the OKS after TKR. THR patients with an OHS ≥ 42 and TKR patients with an OKS ≥ 37 had a higher NRS for satisfaction and a greater likelihood of being willing to undergo surgery again. Conclusions. PASS thresholds appear larger at mid-term follow-up than at six months after surgery. With- out external validation, we would advise against using these PASS thresholds as absolute thresholds in defining whether or not a patient has attained an acceptable symptom state after THR or TKR. Cite this article: Bone Joint Res 2014;3:7–13

Introduction: Patients following resurfacing frequently remark about the natural feel of the resurfaced hip joint in contrast to those with total hip arthroplasty. Possible reasons for this include the larger femoral head size, conservation of bone and superior biomechanics of the implant with more accurate restoration of femoral offset, leg length and femoral anteversion. Our aim was to assess femoral offset and leg length following hip resurfacing and hybrid THR (uncemented acetabulum) performed by the same surgeon. Methods: A consecutive group of patients were identified (35 resurfacing and 25 hybrid). AP pelvis radiographs were evalulated, films with evidence of malrotation or inadequate imaging of the femur were excluded, leaving 21 resurfacing and 15 hybrid. Comparison was made between the pre-op and post-op films together with the contralateral hip on the same film. Patients with hip dysplasia or significant pathology in the contralateral hip were excluded. Magnification of the films was measured by comparison of the templated diameter of the implanted femoral head and the acutal diameter of the implant. To allow comparison between pre-op films a measurement was taken between the obturaror foraminae. All films were analysed by the same investigator using the technique described by Jolles et al (J Arthroplasty 2002). A horizontal line was drawn between the base of the teardrop on both sides, and perpendicular lines drawn from the back of the teardrops. The anatomical femoral axis was drawn and femoral offset measured from this. The centre of rotation of the femoral head was determined by templating and the acetabular offset obtained. Distance from tip of the greater trochanter to the centre of the femoral head in the axis of the femur was determined on pre and post-op films, as this shows little variation with rotation of the femur. Leg length was measured from the horizontal line to the tip of the greater trochanter together with the angle between the femoral axis and the horizontal to correct for abduction of the hip. Results: Mean total femoral offset compared to the contralateral side was −1.3mm (SD 5.3) and −3.2mm (SD 6.5) for the resurfacing and hybrid groups respectively. No significant difference was detected in leg length or other measurements. Discussion and Conclusion: No significant differences were demonstrated between femoral offset or leg length in the resurfacing and hybrid arthroplasty groups. This study does not support the hypothesis that resurfacing produces more accurate restoration of hip biomechanics than hybrid total hip arthroplasty

Although the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index was originally developed for the assessment of non-operative treatment, it is commonly used to evaluate patients undergoing either total hip (THR) or total knee replacement (TKR). We assessed the importance of the 17 WOMAC function items from the perspective of 1198 patients who underwent either THR (n = 704) or TKR (n = 494) in order to develop joint-specific short forms. After these patients were administered the WOMAC pre-operatively and at three, six, 12 and 24 months’ follow-up, they were asked to nominate an item of the function scale that was most important to them. The items chosen were significantly different between patients undergoing THR and those undergoing TKR (p < 0.001), and there was a shift in the priorities after surgery in both groups. Setting a threshold for prioritised items of ≥ 5% across all follow-up, eight items were selected for THR and seven for TKR, of which six items were common to both. The items comprising specific WOMAC-THR and TKR function short forms were found to be equally responsive compared with the original WOMAC function form. . Cite this article: Bone Joint J 2013;95-B:239–43

Aims: In 1979 a national observation study of total hip arthroplasties was started in Sweden. The Swedish Hip Register describes the epidemiology of primary and revision surgery and identifies risk factors for failure. Every unit reports details concerning implants, surgical and cementing technique and revision procedures online via the Internet home page (. www.jru.orthop.gu.se. ). Methods: Currently the register contains 203 625 primary total hip arthroplasties performed during 1979–2001 and 18 067 revision procedures. Revision is the failure endpoint definition and modified Kaplan-Meier statistics and Poisson models are used for survival analysis. Each hospital receive their results annually providing a system for continuous improvement. Results: The results show that serious complications have declined significantly despite an increasing number of patients at risk. The revision burden for cemented THR (94% of the implants are cemented) is only 7.5%, which is much lower than in other countries. Over the 22 year period revision for aseptic loosening has been reduced to one quarter. Demographics are important since male gender and young age significantly increase the risk for revision. Cementless implants have in general had a worse outcome than expected but improved during the last decade. Conclusion: Problem areas are the young population and revision surgery which must be improved. The revision burden is about two times higher in all other countries. This finding implies that the register is extremely cost-effective and the reduction in direct costs for the health care service in Sweden corresponds to approximately USD 140 millions over the last ten years

Aims: In younger patients with dysplastic hip we come to the polemic Ð THR or joint-saving operation? The purpose of this presentation is to introduce the indications and the results of joint-saving operations as performed at our department. Methods: We analyzed patients with dysplastic hip, who undergone a joint-saving surgery at our department in past years 1997 Ð 2002. As those were younger patients, we indicated osteotomy Ð Chiari, Salter, Dega as well as pelvic osteotomy with the use of bone allograft. In all the patients we also performed a debridement and intertrochanteric osteotomy. In patients with signs of femoral head necrosis we performed transtrochanteric rotation osteotomy sec Sugioka. The postoperative following of the patients was 6 months to 5 years. Results: In years 1997 Ð 2002 we performed 7500 operations, 62 of them were pelvic osteotomies combined with intertrochanteric osteotomy and debridement of the hip. The age of patients varied between 18 and 68 years, 37 of them were women and 25 men. Oldest men was 58, youngest 24 years, oldest woman was 68 years and the youngest one was 18 years old. In 22 patients (35,5%) the results were very good, in 29 patients (46,8%) patients the results were good, in 3 patients (4,8%) the results were not sufþcient. In 8 patients (12,9%) the state remained unchanged. Conclusions: The results of above mentioned operations performed at The 2nd Department of Orthopaedic at the Faculty of Medicine of Comenius University, Bratislava, show good results. We continue indicating the combined one-stage osteotomy of the pelvis with intertrochanteric osteotomy and debridement of the hip

In fall 2004 we started with minimal invasive hip surgery at our clinic. Our requirements: Use of our standard implant system (Bicon threaded cup and Zweymüller stem), fast realization of the minimal invasive procedure through the continuation of the used, anterolateral Watson-Jones approach, modified for this technique, retaining the supine position with unchanged orientation concerning the positioning of the implant parts. Our expectations: Reduction in operative trauma through lower blood loss with less post-operative pain, less limping especially during the first weeks, less trochanter pain through the preservation of the gluteal muscle tendons, fewer posterior dislocations by preservation of the dorsal capsule, and a better cosmetic result. The patient is placed in supine position on the standard OR table with the option of tilting the legs down. The contralateral leg lies on a leg holder in extended position, flexed by approx. 20 degrees. This allows to bring the leg in hyperextension (without hyperlordosis of the lumbar spine), adduction and external rotation during broaching the femur. The main criterion of the minimal invasivness is the preservation of the gluteal tendons and not primarily the reduction of the length of the skin incision. An extensive capsular release with partial dissection of the rectus tendon for exposure of the acetabulum is necessary. For the stem implantation a notching of the piriformis can be necessary in addition to this. During the stem preparation the soft tissues should not influence the axial entrance of the rasps into the femoral canal otherwise there is a danger of a dorsolateral perforation. Right-left-lateral-double-offset rasps and the use of manipulation rasps as trial prostheses have worked satisfactorily. Retrospective analyses of numerous peri- and post-operative data were accomplished, as well as radiological evaluations regarding the optimal position of the implanted joints, and compared with a conventional control group. After a learning curve the OP duration was the same in both groups. The development of the haemoglobin and hematocrit levels were identical, 1/3 of the patients needed blood subsitution (autologous or stored blood). 90% of the analysed postoperative x-rays in standing position showed equal bilateral leg length corresponding to the preoperative planning, the planned offset was achieved in 93%. Deviations of the remaining were without clinical relevance. The complication rate was 2,5%. Conclusions: The anterolaterale approach in supine position is standardised for the minimal invasive THR. The compliance with the developed implantation technique is a requirement for the optimal positioning of the prosthesis and to avoid complications. The subjective patient assessments, especially of those who experienced both methods, are impressive

Purpose: The original AML prosthesis was fully coated and later the manufacturer switched it to 5/8ths coating. The second generation Prodigy femoral component was developed to return to full coating of the prosthesis and to provide a medial relief to decrease bone stress shielding. The purpose of this study was to evaluate the minimum ten year results using this device and to compare the results to the same surgeon’s results at 10 years using a first generation proximally coated device. Method: 100 consecutive primary total hip replacements were performed by a single surgeon in 86 patients using the Prodigy (DePuy, Warsaw, Indiana) femoral component between 1994 and 1997. The components were mated with 80 HGI and 20 Duraloc acetabular components. Patients were evaluated with WOMAC ratings, need for revision and radiographic loosening. The same parameters had been evaluated at minimum 10-year follow-up for the same surgeon’s initial 100 consecutive PCA (Stryker, New Jersey) primary THR’s and were compared to the present series. Results: At minimum 10 year follow-up, 71 patients with 83 hips were living. The average clinical follow-up for the living patients was 11 years (range 10 to 12 years) and the average radiographic follow-up was 9.2 years for this group (range 7–12 years). No femoral component was revised for loosening and all femoral components were bone ingrown on radiographs. 7 acetabular components required a liner exchange or revision for polyethylene wear. This compares favorably to the same surgeon’s 10 year results with the PCA where 6 femoral components were revised for wear or loosening and an additional 2 were radiographically loose. Conclusion: The Prodigy femoral component demonstrated excellent durability at 10 years. With the newer cementless stems with a wide variety of sizes, femoral loosening is rarely a clinical problem

Patient expectations and their fulfilment are an important factor in determining patient-reported outcome and satisfaction of hip (THR) and knee replacement (TKR). The aim of this prospective cohort study was to examine the expectations of patients undergoing THR and TKR, and to identify differences in expectations, predictors of high expectations and the relationship between the fulfilment of expectations and patient-reported outcome measures. During the study period, patients who underwent 346 THRs and 323 TKRs completed an expectation questionnaire, Oxford score and Short-Form 12 (SF-12) score pre-operatively. At one year post-operatively, the Oxford score, SF-12, patient satisfaction and expectation fulfilment were assessed. Univariable and multivariable analysis were performed. Improvements in mobility and daytime pain were the most important expectations in both groups. Expectation level did not differ between THR and TKR. Poor Oxford score, younger age and male gender significantly predicted high pre-operative expectations (p < 0.001). The level of pre-operative expectation was not significantly associated with the fulfilment of expectations or outcome. THR better met the expectations identified as important by patients. TKR failed to meet expectations of kneeling, squatting and stair climbing. High fulfilment of expectation in both THR and TKR was significantly predicted by young age, greater improvements in Oxford score and high pre-operative mental health scores. The fulfilment of expectations was highly correlated with satisfaction

Introduction: We perform MIS since 2004 and have done 1257 THR (SL-Plus stem and since 2005 SL MIA stem with a modification in the proximal part). The operation is performed with the anterolateral approach in supine position under direct view with visible landmarks. Material and Methods: Till know we implanted 357 THR with the new designed stem and the BICON threaded cup. A precise preoperative planning for implant size, neck length and offset is obligatory and is performed with manuel templanting or digital planning on AP X-ray in standing position. We evaluated used sizes of standard and offset stems and cups, neck length, material of bearing surfaces and on the AP X-ray postoperative in standing position the inclination and anteversion angle of the cup as well as the stem position, postoperative leg length and Trendelenburg sign. Results: According to the preoperative templating we used offset stems in 30%. of our patients. The neck length small in 14%, medium in 46%, large in 40%. The range of cup inclination angle was in safe zone with an average of 45,8°, neutral stem position in 92,2%. Leg length equal in 73% and lengthening or shortening +/−in average 8,4mm and 6,5 mm. The Trendelenburg sign was negativ in 93% at the time of removal of skin sutures. Conculsion: The requirement for precise positioning of implant, leg length and muscular function are full-filled with our minimal invasive technique. Also more demanding bearing couples as CC are not at risk

It has recently been reported that the transverse acetabular ligament (TAL) is helpful in determining the position of the acetabular component in total hip replacement (THR). In this study we used a computer-assisted navigation system to determine whether the TAL is useful as a landmark in THR. The study was carried out in 121 consecutive patients undergoing primary THR (134 hips), including 67 dysplastic hips (50%). There were 26 men (29 hips) and 95 women (105 hips) with a mean age of 60.2 years (17 to 82) at the time of operation. After identification of the TAL, its anteversion was measured intra-operatively by aligning the inferomedial rim of the trial acetabular component with the TAL using computer-assisted navigation. The TAL was identified in 112 hips (83.6%). Intra-observer reproducibility in the measurement of anteversion of the TAL was high, but inter-observer reproducibility was moderate. . Each surgeon was able to align the trial component according to the target value of the angle of anteversion of the TAL, but it was clear that methods may differ among surgeons. Of the measurements of the angle of anteversion of the TAL, 5.4% (6 of 112 hips) were outliers from the safe zone. In summary, we found that the TAL is useful as a landmark when implanting the acetabular component within the safe zone in almost all hips, and to prevent it being implanted in retroversion in all hips, including dysplastic hips. However, as anteversion of the TAL may be excessive in a few hips, it is advisable to pay attention to individual variations, particularly in those with severe posterior pelvic tilt. Cite this article: Bone Joint J 2014;96-B:306–11

The debate whether to use cemented or uncemented components in primary total hip replacement (THR) has not yet been considered with reference to the cost implications to the National Health Service. We obtained the number of cemented and uncemented components implanted in 2009 from the National Joint Registry for England and Wales. The cost of each component was established. The initial financial saving if all were cemented was then calculated. Subsequently the five-year rates of revision for each type of component were reviewed and the predicted number of revisions at five years for the actual components used was compared with the predicted number of revisions for a cemented THR. This was then multiplied by the mean cost of revision surgery to provide an indication of the savings over the first five years if all primary THRs were cemented. The saving at primary THR was calculated to be £10 million with an additional saving during the first five years of between £5 million and £8.5 million. The use of cemented components in routine primary THR in the NHS as a whole can be justified on a financial level but we recognise individual patient factors must be considered when deciding which components to use

Autologous retransfusion and no-drainage are both blood-saving measures in total hip replacement (THR). A new combined intra- and post-operative autotransfusion filter system has been developed especially for primary THR, and we conducted a randomised controlled blinded study comparing this with no-drainage. A total of 204 THR patients were randomised to autologous blood transfusion (ABT) (n = 102) or no-drainage (n = 102). In the ABT group, a mean of 488 ml (. sd. 252) of blood was retransfused. The mean lowest post-operative haemoglobin level during the hospital stay was higher in the autotransfusion group (10.6 g/dl (7.8 to 13.9) vs 10.2 g/dl (7.5 to 13.3); p = 0.01). The mean haemoglobin levels for the ABT and no-drainage groups were not significantly different on the first day (11.3 g/dl (7.8 to 13.9) vs 11.0 g/dl (8.1 to 13.4); p = 0.07), the second day (11.1 g/dl (8.2 to 13.8) vs 10.8 g/dl (7.5 to 13.3); p = 0.09) or the third day (10.8 g/dl (8.0 to 13.0) vs 10.6 g/dl (7.5 to 14.1); p = 0.15). The mean total peri-operative net blood loss was 1464 ml (. sd. 505) in the ABT group and 1654 ml (. sd. 553) in the no-drainage group (p = 0.01). Homologous blood transfusions were needed in four patients (3.9%) in the ABT group and nine (8.8%) in the no-drainage group (p = 0.15). No statistically significant difference in adverse events was found between the groups. The use of a new intra- and post-operative autologous blood transfusion filter system results in less total blood loss and a smaller maximum decrease in haemoglobin levels than no-drainage following primary THR. Cite this article: Bone Joint J 2013;95-B:616–22