Introduction: Although
Introduction. Corrosion products from modular taper junctions of hip prostheses have been implicated in adverse local tissue reactions after
Background. As the number of ceramic
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
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
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
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
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
Introduction: Outcome reporting following
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
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
The choice to use alumina in the manufacture of a low-wear
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
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
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
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
Summary Statement. This data may help explain the variability in physical function after primary TKR as compared to primary
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
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
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