There are concerns regarding initial stability and early periprosthetic fractures in cementless hip arthroplasty using short stems. This study aimed to investigate stress on the cortical bone around the stem and micromotions between the stem and cortical bone according to femoral stem length and positioning. In total, 12 femoral finite element models (FEMs) were constructed and tested in walking and stair-climbing. Femoral stems of three different lengths and two different positions were simulated, assuming press-fit fixation within each FEM. Stress on the cortical bone and micromotions between the stem and bone were measured in each condition.Aims
Methods
We wanted to evaluate the effects of a bone anabolic agent (bone morphogenetic protein 2 (BMP-2)) on an anti-catabolic background (systemic or local zoledronate) on fixation of allografted revision implants. An established allografted revision protocol was implemented bilaterally into the stifle joints of 24 canines. At revision surgery, each animal received one BMP-2 (5 µg) functionalized implant, and one raw implant. One group (12 animals) received bone graft impregnated with zoledronate (0.005 mg/ml) before impaction. The other group (12 animals) received untreated bone graft and systemic zoledronate (0.1 mg/kg) ten and 20 days after revision surgery. Animals were observed for an additional four weeks before euthanasia.Aims
Methods
COVID-19 has compounded a growing waiting list problem, with over 4.5 million patients now waiting for planned elective care in the UK. Views of patients on waiting lists are rarely considered in prioritization. Our primary aim was to understand how to support patients on waiting lists by hearing their experiences, concerns, and expectations. The secondary aim was to capture objective change in disability and coping mechanisms. A minimum representative sample of 824 patients was required for quantitative analysis to provide a 3% margin of error. Sampling was stratified by body region (upper/lower limb, spine) and duration on the waiting list. Questionnaires were sent to a random sample of elective orthopaedic waiting list patients with their planned intervention paused due to COVID-19. Analyzed parameters included baseline health, change in physical/mental health status, challenges and coping strategies, preferences/concerns regarding treatment, and objective quality of life (EuroQol five-dimension questionnaire (EQ-5D), Generalized Anxiety Disorder 2-item scale (GAD-2)). Qualitative analysis was performed via the Normalization Process Theory.Aims
Methods
The aim of the Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) was to determine the optimal treatment for adults with a bicortical undisplaced or minimally displaced fracture of the waist of the scaphoid, comparing early surgical fixation with initial cast immobilization, with immediate fixation being offered to patients with nonunion. A cost-effectiveness analysis was conducted to assess the relative merits of these forms of treatment. The differences in costs to the healthcare system and quality-adjusted life years (QALYs) of the patients over the one-year follow-up of the trial in the two treatment arms were estimated using regression analysis.Aims
Methods
The purpose of this study was to determine whether
it would be feasible to use oblique lumbar interbody fixation for
patients with degenerative lumbar disease who required a fusion
but did not have a spondylolisthesis. A series of CT digital images from 60 patients with abdominal
disease were reconstructed in three
With greater numbers of younger patients undergoing
total hip replacement (THR), the effect of patient age on the diameter
of the femoral canal may become more relevant. This study aimed
to investigate the relationship between the diameter of the diaphysis
of the femoral canal with increasing age in a large number of patients
who underwent THR. A total of 1685 patients scheduled for THR had
their femoral
Several factors have been implicated in unsatisfactory
results after total hip replacement (THR). We examined whether femoral
offset, as measured on digitised post-operative radiographs, was
associated with pain after THR. The routine post-operative radiographs
of 362 patients (230 women and 132 men, mean age 70.0 years (35.2
to 90.5)) who received primary unilateral THRs of varying designs
were measured after calibration. The femoral offset was calculated
using the known
The use of 3D-printed titanium implant (DT) can effectively guide bone regeneration. DT triggers a continuous host immune reaction, including macrophage type 1 polarization, that resists osseointegration. Interleukin 4 (IL4) is a specific cytokine modulating osteogenic capability that switches macrophage polarization type 1 to type 2, and this switch favours bone regeneration. IL4 at concentrations of 0, 30, and 100 ng/ml was used at day 3 to create a biomimetic environment for bone marrow mesenchymal stromal cell (BMMSC) osteogenesis and macrophage polarization on the DT. The osteogenic and immune responses of BMMSCs and macrophages were evaluated respectively.Aims
Methods
Limb alignment in total knee arthroplasty (TKA) influences periarticular soft-tissue tension, biomechanics through knee flexion, and implant survival. Despite this, there is no uniform consensus on the optimal alignment technique for TKA. Neutral mechanical alignment facilitates knee flexion and symmetrical component wear but forces the limb into an unnatural position that alters native knee kinematics through the arc of knee flexion. Kinematic alignment aims to restore native limb alignment, but the safe ranges with this technique remain uncertain and the effects of this alignment technique on component survivorship remain unknown. Anatomical alignment aims to restore predisease limb alignment and knee geometry, but existing studies using this technique are based on cadaveric specimens or clinical trials with limited follow-up times. Functional alignment aims to restore the native plane and obliquity of the joint by manipulating implant positioning while limiting soft tissue releases, but the results of high-quality studies with long-term outcomes are still awaited. The drawbacks of existing studies on alignment include the use of surgical techniques with limited accuracy and reproducibility of achieving the planned alignment, poor correlation of intraoperative data to long-term functional outcomes and implant survivorship, and a paucity of studies on the safe ranges of limb alignment. Further studies on alignment in TKA should use surgical adjuncts (e.g. robotic technology) to help execute the planned alignment with improved accuracy, include intraoperative assessments of knee biomechanics and periarticular soft-tissue tension, and correlate alignment to long-term functional outcomes and survivorship.
Although total knee arthroplasty (TKA) is a highly successful procedure, about 20% of patients remain dissatisfied postoperatively. This proportion is derived from dichotomous models of the assessment of surgical success or failure, which may not reflect the spectrum of outcomes. The aim of this study was to explore differing responses to surgery, and assess whether there are distinct groups of patients with differing patterns of outcome. This was a secondary analysis of a UK multicentre TKA longitudinal cohort study. We used a group-based trajectory modelling analysis of Oxford Knee Score (OKS) in the first year following surgery with longitudinal data involving five different timepoints and multiple predictor variables. Associations between the derived trajectory groups and categorical baseline variables were assessed, and predictors of trajectory group membership were identified using Poisson regression and multinomial logistic regression, as appropriate. The final model was adjusted for sociodemographic factors (age, sex) and baseline OKS.Aims
Methods
The primary aim was to assess the patient-perceived effect of restrictions imposed due to COVID-19 on rehabilitation following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Secondary aims were to assess perceived restrictions, influence on mental health, and functional outcome compared to patients undergoing surgery without restriction. During February and March 2020, 105 patients underwent THA (n = 48) or TKA (n = 57) and completed preoperative and six-month postoperative assessments. A cohort of 415 patients undergoing surgery in 2019 were used as the control. Patient demographic data, BMI, comorbidities, Oxford Hip Score (OHS) or Knee Score (OKS), and EuroQoL five-domain (EQ-5D) score were collected preoperatively and at six months postoperatively. At six months postoperatively, the 2020 patients were also asked to complete a questionnaire relating to the effect of the social restrictions on their outcome and their mental health.Aims
Methods
The aim of this study was to determine whether national standards of best practice are associated with improved health-related quality of life (HRQoL) outcomes in hip fracture patients. This was a multicentre cohort study conducted in 20 acute UK NHS hospitals treating hip fracture patients. Patients aged ≥ 60 years treated operatively for a hip fracture were eligible for inclusion. Regression models were fitted to each of the “Best Practice Tariff” indicators and overall attainment. The impact of attainment on HRQoL was assessed by quantifying improvement in EuroQol five-dimension five-level questionnaire (EQ-5D-5L) from estimated regression model coefficients.Aims
Methods
Mechanical failure because of wear or fracture of the polyethylene tibial post in posteriorly-stabilised total knee replacements has been extensively described. In this study of 12 patients with a clinically and radiologically successful NexGen LPS posteriorly-stabilised prosthesis impingement of the anterior tibial post was evaluated in vivo in three
The aim of this prospective cohort study was to evaluate the early migration of the TriFit cementless proximally coated tapered femoral stem using radiostereometric analysis (RSA). A total of 21 patients (eight men and 13 women) undergoing primary total hip arthroplasty (THA) for osteoarthritis of the hip were recruited in this study and followed up for two years. Two patients were lost to follow-up. All patients received a TriFit stem and Trinity Cup with a vitamin E-infused highly cross-linked ultra-high molecular weight polyethylene liner. Radiographs for RSA were taken postoperatively and then at three, 12, and 24 months. Oxford Hip Score (OHS), EuroQol five-dimension questionnaire (EQ-5D), and adverse events were reported.Aims
Methods
Poly(methyl methacrylate) (PMMA)-based bone cements are the industry standard in orthopaedics. PMMA cement has inherent disadvantages, which has led to the development and evaluation of a novel silorane-based biomaterial (SBB) for use as an orthopaedic cement. In this study we test both elution and mechanical properties of both PMMA and SBB, with and without antibiotic loading. For each cement (PMMA or SBB), three formulations were prepared (rifampin-added, vancomycin-added, and control) and made into pellets (6 mm × 12 mm) for testing. Antibiotic elution into phosphate-buffered saline was measured over 14 days. Compressive strength and modulus of all cement pellets were tested over 14 days.Aims
Methods
This study sought to compare the rate of deep surgical site infection (SSI), as measured by the Centers for Disease Control and Prevention (CDC) definition, after surgery for a fracture of the hip between patients treated with standard dressings and those treated with incisional negative pressure wound therapy (iNPWT). Secondary objectives included determining the rate of recruitment and willingness to participate in the trial. The study was a two-arm multicentre randomized controlled feasibility trial that was embedded in the World Hip Trauma Evaluation cohort study. Any patient aged > 65 years having surgery for hip fracture at five recruitment centres in the UK was considered to be eligible. They were randomly allocated to have either a standard dressing or iNPWT after closure of the wound. The primary outcome measure was deep SSI at 30 and 90 days, diagnosed according to the CDC criteria. Secondary outcomes were: rate of recruitment; further surgery within 120 days; health-related quality of life (HRQoL) using the EuroQol five-level five-dimension questionnaire (EQ-5D-5L); and related complications within 120 days as well as mobility and residential status at this time.Aims
Methods
Carbon-fibre and polyester-fibre implants of comparable
Periprosthetic femoral fractures (PPF) are a serious complication of total hip arthroplasty (THA) and are becoming an increasingly common indication for revision arthroplasty with the ageing population. This study aimed to identify potential risk factors for PPF based on an analysis of registry data. Cases recorded with PPF as the primary indication for revision arthroplasty in the German Arthroplasty Registry (Endoprothesenregister Deutschland (EPRD)), as well as those classified as having a PPF according to the International Classification of Diseases (ICD) codes in patients’ insurance records were identified from the complete datasets of 249,639 registered primary hip arthroplasties in the EPRD and included in the analysis.Aims
Methods
Ideal component sizing may be difficult to achieve in unicompartmental knee arthroplasty (UKA). Anatomical variants, incremental implant size, and a reduced surgical exposure may lead to over- or under-sizing of the components. The purpose of this study was to compare the accuracy of UKA sizing with robotic-assisted techniques versus a conventional surgical technique. Three groups of 93 medial UKAs were assessed. The first group was performed by a conventional technique, the second group with an image-free robotic-assisted system (Image-Free group), and the last group with an image-based robotic arm-assisted system, using a preoperative CT scan (Image-Based group). There were no demographic differences between groups. We compared six parameters on postoperative radiographs to assess UKA sizing. Incorrect sizing was defined by an over- or under-sizing greater than 3 mm.Aims
Methods
We report three cases of thoracic spine translocation without neurological deficit. In each case bilateral pedicular fractures, demonstrated by computed tomography, produced 'floating arches' which account for the sparing of the cord. If computed tomography demonstrates adequate canal