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

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:. 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

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

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. 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

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: 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:. 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. 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. 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

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

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

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

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

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

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