National Institute for Health and Clinical Excellence (NICE) guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractured neck of femur (NOF) in cognitively intact patients who were independently mobile prior to the injury. The National Joint Registry for England and Wales (NJR) has collected data on THRs performed since 2003. This retrospective cohort study explores risk factors independently associated with implant failure and perioperative mortality. NJR data recording a THR performed for acute fractured NOF between 2003 and 2010 were analysed. Cox proportional hazards models were used to analyse the extent to which risk of implant revision was related to specific covariates. Multivariable logistic regression was used to analyse factors affecting 90-day perioperative mortality. Significance was taken as p< 0.01.Introduction
Methods
Current analysis of unicondylar knee replacements (UKR) by national registries is based on the pooled results of medial and lateral implants. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of lateral UKR implanted, their survival and reason for failure in comparison to medial UKR. By combining information on the side of operation with component details held on the NJR we were able to determine implant laterality (medial vs. lateral) for 32,847 of the 35,624 (92%) UKR registered before December 2010. Kaplan Meier plots, Life tables and Cox' proportion hazards were used to compare the risk of failure for lateral and medial UKRs after adjustment for patient and implant covariates.Background
Methods
Both surgeon and hospital volume influence patient outcomes following revision knee arthroplasty. To audit all centres performing revision knee procedures in England and Wales over a 2-year period. All centres were audited against two pre-defined standards linked to hospital volume Operative volume should be greater than 10 revisions per year; More than 2.5 revisions should be performed for every 100 primary arthroplasties implanted.Background
Purpose
Following in-depth analysis of the market leading brand combinations in which we identified implant influences on risk of revision, we compared revision in patients implanted with different categories of hip replacement in order to find implant with the lowest revision risk, once known flawed options were removed. All patients with osteoarthritis who underwent a hip replacement (2003–2010) using an Exeter-Contemporary (cemented), Corail-Pinnacle (cementless), Exeter-Trident (Hybrid) or a Birmingham Hip resurfacing (BHR) were initially included within the analysis. Operations involving factors that were significant predictors of revision were excluded. Cox proportional hazard models were then used to assess the relative risk of revision for a category of implant (compared with cemented), after adjustment for patient covariates.Introduction
Methods
To determine how patient characteristics; health status and pre-operative knee function effect patient reported satisfaction and operative success following total knee replacement (TKR). We hypothesised that a number of patient factors would influence the reported levels of symptomatic improvement (success) and satisfaction and that these two outcomes would represent different aspects of the patient's perception of outcome. Retrospective cohort analysis of patient reported outcome measures (PROMs) and National Joint Registry (NJR) data. Complete patient data was available for 9,874 TKRs performed for osteoarthritis between 1/8/08 and 31/12/10. The relationship of the background factors to patient perceived satisfaction and success was investigated using ordinal logistic regression and structural equation modelling (SEM).Purpose
Design
The most appropriate form of chemical thromboprophylaxis following knee replacement is a contentious issue. Most national guidelines recommend the use of low molecular weight Heparin (LMWH) whilst opposing the use of aspirin. We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or LMWH. Data from the National Joint Registry for England and Wales was linked to an administrative database of hospital admissions in the English National Health Service. A total of 156 798 patients undergoing knee replacement between April 2003 and September 2008 were included and followed up for 90 days. Multivariable risk modelling was used to estimate odds ratios adjusted for baseline risk factors (AOR). An AOR < 1 indicates that risk rates are lower with LMWH than with aspirin.Background
Methods
There is a lack of information on the independent preoperative predictors of perioperative mortality, including the influence of previous stroke and acute coronary syndromes (myocardial infarction + unstable angina, ACS). Previous studies have grouped variables under the umbrella term “ischaemic heart disease”. In this study, we investigated the influence of vascular risk factors separately. The Hospital Episode Statistics database was analyzed for elective admissions for total hip (THR) and total knee (TKR) replacements between 2004 and 2009. Independent preoperative predictors of perioperative outcome were identified from admission secondary diagnosis codes. Perioperative mortality was defined as 30-day in-hospital death. Logistic regression analysis was used to identify independent predictors of 30-day mortality. Data was adjusted for age, social deprivation and Charlson co-morbidity score.Background
Methods
Dislocation is a major complication following total hip arthroplasty (THA). Aetiology is multi-factorial, but increasing femoral head size may result in lower dislocation rates. The latest England and Wales National Joint Registry (NJR) annual report has highlighted a statistically significant increase in the use of femoral heads of size 36mm+ from 5% in 2005 to 26% in 2009, together with an increase in the use of the posterior approach. The aim of this study was to determine whether national dislocation rates have fallen over the same period. Hospital episode statistics (HES) data for England was analysed so as to determine trends in national rates of 3-, 6-, 12- and 18-month dislocation rates following primary THA performed between 2005 and 2009 (247,546 THAs). 18-month revision rates were also examined.Background
Methods
Medical complications and death are rare events following elective orthopaedic surgery. Diagnostic and operative codes are routinely collected on every patient admitted to English NHS hospitals. This is the first study investigating rates of these events following total joint replacement (TJR) on a national scale. All patients (585177 patients) who underwent TJR (hip arthroplasty [THR], knee arthroplasty [TKR], or hip resurfacing) between 2005 and 2010 were identified. Patients were subdivided based on Charlson co-morbidity score. Data was extracted on 30-day complication rates for myocardial infarction (MI), cerebrovascular event (CVA), chest infection (LRTI), renal failure (RF), pulmonary embolus (PE) and inpatient 90-day mortality (MR).Background
Methods
The National Institute for Health and Clinical Effectiveness recommends both low molecular weight heparin (LMWH) and Rivaroxaban for venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. Despite evidence in the literature that suggests Rivaroxaban reduces VTE events, there are emerging concerns from the orthopaedic community regarding an increase in wound complications following its use. Through the orthopaedic clinical directors forum, Trusts replacing LMWH with Rivaroxaban for lower limb arthroplasty thromboprophylaxis during 2009 were identified. Prospectively collected Hospital episode statistics (HES) data was then analysed for these units so as to determine rates of 90-day symptomatic deep venous thrombosis (DVT), pulmonary embolism (PE), major bleed (cerebrovascular accident or gastrointestinal haemorrhage), all-cause mortality, and 30-day wound infection and readmission rates before and after the change to Rivaroxaban. 2752 patients prescribed Rivaroxaban following TKR or THR were compared to 10358 patients prescribed LMWH. Data was analysed using odds ratios (OR).Background
Methods
A recent Cochrane review has shown that total shoulder arthroplasty (TSA) seems to offer an advantage in terms of shoulder function over hemiarthroplasty, with no other obvious clinical benefits. This is the first study to compare complication rates on a national scale. All patients (9804 patients) who underwent either TSA or shoulder hemiarthroplasty as a planned procedure between 2005 and 2008 in the English NHS were identified using the hospital episodes statistic database. Data was extracted on 30-day rates of readmission, wound complications, reoperation and medical complications (myocardial infarction (MI) and chest infection (LRTI)), and inpatient 90-day DVT, PE and mortality rates (MR). Revision rate at 18 months was analysed for the whole cohort and, for a subset of 939 patients, 5-year revision rate. Odds ratio (OR) was used to compare groups.Background
Methods
In 2011 20% of intracapsular fractured neck of femurs were treated with an uncemented hemiarthroplasty in the English NHS. National guidelines recommend cemented implants, based on evidence of less pain, better mobility and lower costs. We aimed to compare complications following cemented and uncemented hemiarthroplasty using the national hospital episode statistics (HES) database in England. Dislocation, revision, return to theatre and medical complications were extracted for all patients with NOF fracture who underwent either cemented or uncemented hemiarthroplasty between January 2005 and December 2008. To make a ‘like for like’ comparison all 30424 patients with an uncemented impant were matched to 30424 cemented implants (from a total of 42838) in terms of age, sex and Charlson co-morbidity score.Background
Methods
Bearing diameter and acetabular component orientation have been shown to be important variables effecting blood metal ion levels following hip resurfacing arthroplasty. So far no studies on bilateral hip resurfacings have taken into account these variables. We examined the serum ion results of patients under the care of two experienced hip resurfacing surgeons who carry out ion analysis as part of routine post operative care. Surgeon 1: Patients were implanted exclusively with a “third generation” resurfacing device. Surgeon 2: Patients were implanted with the same “third generation” device and also a low clearance “fourth generation” resurfacing device. Only ion results from patients who were 12 months post surgery were included. Bilateral patients were matched to unilateral patients according to the surgeon performing the operation; the resurfacing system implanted and cup inclination and anteversion angles. The ion data from each bilateral group was tested against the corresponding unilateral groups using the Mann Whitney U test for non parametric data. Significance was drawn at p<0.05. Surgeon 1: There were 310 patients with unilateral joints and 50 with bilateral joints. There were no significant differences with regard to time to follow up, activity levels, joint sizes or cup orientations. Serum chromium (Cr) and cobalt (Co) concentrations were significantly greater in the bilateral group (p<0.001). Median ion levels were greater in the bilateral group by a factor of >2 in the smallest joint sizes and <2 in the largest joints. Surgeon 2: There were 11 patients with bilateral third generation resurfacing joints and 50 with unilateral joints of the same design. The same relationship as described above was identified. There was a notable difference in the fourth generation implant group (n=13 bilateral, n=100 unilateral). Median ion levels for patients receiving bilateral joints of sizes <47mm were ten times greater than in the corresponding unilateral group. Bearing diameter and component design are critical factors in determining metal ion levels following bilateral hip resurfacings. Surgeons must consider the potential implications of gross increases in metal ion levels prior to performing bilateral hip resurfacings in smaller patients.
