Anxiety and depression are risk factors for poor outcome following knee replacement surgery. The aim of this study was to investigate the prevalence of anxiety and depression before and after primary (pKR) and revision knee replacement (rKR). Retrospective cohort study. 315,720 pKR and 12,727 rKR recruited from the NHS Patient Reported Outcome Measures (PROMs) programme from 2013–2021. Anxiety and depression were defined using: (i) Survey question: “Have you been told by a doctor that you have depression? Yes/No”; (ii) EQ-5D anxiety/depression domain. Rates of EQ-5D anxiety/depression were investigated at baseline and at 6-months following surgery. The prevalence of depression was investigated by patient age and gender.Abstract
Introduction
Methodology
This multi-centre randomised controlled trial evaluated the clinical and cost effectiveness of liposomal bupivacaine for pain and recovery following knee replacement. 533patients undergoing primary knee replacement were randomised to receive either liposomal bupivacaine (266mg) plus bupivacaine hydrochloride (100mg) or control (bupivacaine hydrochloride 100mg), administered at the surgical site. The co-primary outcomes were pain visual analogue score (VAS) area under the curve (AUC) 6 to 72hours and the Quality of Recovery 40 (QoR-40) score at 72hours.Abstract
Introduction
Methodology
Our aim was to investigate trends in the incidence rate and main indication for revision knee replacement (rKR) over the past 15 years in the UK. Cross-sectional study from 2006 - 2020 using data from the National Joint Registry (NJR). Crude incidence rates were calculated using population statistics from the Office for National Statistics.Abstract
Introduction
Methodology
There is a lack of evidence as to the best way to deliver rehabilitation following TKA. Previous work has suggested that postoperative physiotherapy applied to all patients is not effective at improving one-year post-surgical outcomes. The aim of this study was to target physiotherapy to those at risk of poor outcome following TKA, and to determine if a therapist-led intervention offered superior results compared to a home-exercise based protocol in this ‘at risk’ group. The Targeted Rehabilitation to Improve Outcomes (TRIO) study was a prospective randomised controlled trial run at 15-centres in the UK. Patients were identified as ‘potential poor outcome’ based on an Oxford Knee Score (OKS) classification at 6-weeks post-surgery and randomised to either therapist-led or home-exercise based protocols. Patients were reviewed by a physiotherapist and commenced 18-exercise sessions over 6-weeks. The therapist-led group undertook a progressive functional protocol (modified weekly in 1-1 contact sessions) in contrast to the static home-exercise based regime. Evaluation took place following rehabilitation intervention, then at 6-months and 1-year post-surgery. Primary outcome was comparative group OKS at 1-year. Secondary outcomes included, ‘worst’ and ‘average’ pain scores, OXS and EQ-5D, and satisfaction questionnaire. Health economic (cost-utility) analysis was undertaken from NHS perspective up to 1-year post-surgery. Incremental cost per Quality Adjusted Life Years (QALYs) were calculated from intervention costs, patient reported primary and secondary care usage, and EQ-5D data. 4264 patients were screened, 1296 were eligible, 334 patients were randomised, 8 were lost to follow-up, therapy compliance was >85%. Clinically meaningful improvement in OKS (between baseline and 1-year) was seen in both arms (p < 0 .001). Between group difference in 1-year OKS was 1.91 (95%CI, −0.17–3.99) points favouring the therapist-led arm (p=0.07). Incorporating all time point data, between group difference in OKS was 2.25 points (95%CI, 0.61–3.90, p=0.008). Small, non-significant reductions (< 5 %) in both worst and average pain scores were observed favouring the therapist-led group. Enhanced satisfaction with pain relief (OR 1.65, p < 0 .02), ability to perform daily functional tasks (OR 1.66, p < 0 .02), and perform heavy functional tasks (OR 1.6, p=0.04) was reported in the therapist-led group. There was a small non-significant difference of 0.02 points (95%CI −0.02–0.06) between groups in EQ-5D, resulting in a £12,125 cost per QALY of delivering the therapist led intervention with a 57% chance of being cost-effective at the standard UK policy threshold of £20,000 per QALY. TRIO is the largest randomised trial of physiotherapy following TKA, and the first to target rehabilitation to patients at risk of poor outcomes. Both therapist-led and home-exercise based rehabilitation groups made clinically meaningful improvements in outcome by 1-year. We observed a modest difference in OKS in favour of therapist-led rehabilitation compared to the home-exercises which was not statistically significant. The relatively tight confidence intervals suggests that any difference which might exist is too small to be clinically relevant. Patient satisfaction with outcome was however higher in those that received greater physiotherapist contact. While cost per QALY estimates were below UK policy threshold, this result is uncertain and insufficient to make accept-decline recommendations.
To assess how the cost-effectiveness of total hip arthroplasty (THA) and total knee arthroplasty (TKA) varies with age, sex, and preoperative Oxford Hip or Knee Score (OHS/OKS); and to identify the patient groups for whom THA/TKA is cost-effective. We conducted a cost-effectiveness analysis using a Markov model from a United Kingdom NHS perspective, informed by published analyses of patient-level data. We assessed the cost-effectiveness of THA and TKA in adults with hip or knee osteoarthritis compared with having no arthroplasty surgery during the ten-year time horizon.Aims
Methods
This article reviews four commonly used approaches to assess patient responsiveness to a treatment or therapy [Return To Normal (RTN), Minimal Important Difference (MID), Minimal Clinically Important Difference (MCID), OMERACT-OARSI (OO)], and demonstrates how each of the methods can be formulated in a multi-level modelling (MLM) framework. Data from the Arthroplasty Pain Experience (APEX) cohort study was used. Patients undergoing total hip and knee replacement completed the Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire prior to surgery and then at 3, 6 and 12 months after surgery. We compare baseline scores, change scores, and proportion of individuals defined as “responders” using traditional and multi-level model (MLM) approaches to patient responsiveness.Background
Methods
Knee arthroplasty is an effective intervention for painful arthritis when conservative measures have failed. Despite recent advances in component design and implantation techniques, a significant proportion of patients experience problems relating to the patella-femoral joint (PFJ). Detailed knowledge of the shape and orientation of the normal and replaced femoral trochlea groove is critical when considering potential causes of anterior knee pain. Furthermore, to date it has proved difficult to establish a diagnosis due to shortcomings in current imaging techniques for obtaining satisfactory coronal plane motion data of the patella in the replaced knee. The aim of this study was to correlate the trochlea shape of normal and replaced knees with corresponding coronal plane PFJ kinematic data. Bony and cartilagenous trochlea geometries from 3T MRI scans of 20 normal healthy volunteers were compared with both anatomical and standard total knee replacements (TKR) and patellofemoral joint replacement (PFJR) geometries. Following segmentation and standardized alignment, the path of the apex of the trochlea groove was measured using customized Matlab software. (Fig1). Next, kinematic data of the 20 normal healthy volunteers (Normal) was compared with that of 20 TKR, and 20 PFJR patients using the validated MAUSTM system Introduction
Method
The Swansea Morriston Achilles Rupture Treatment
(SMART) programme was introduced in 2008. This paper summarises
the outcome of this programme. Patients with a rupture of the Achilles
tendon treated in our unit follow a comprehensive management protocol
that includes a dedicated Achilles clinic, ultrasound examination,
the use of functional orthoses, early weight-bearing, an accelerated
exercise regime and guidelines for return to work and sport. The
choice of conservative or surgical treatment was based on ultrasound
findings. The rate of re-rupture, the outcome using the Achilles Tendon
Total Rupture Score (ATRS) and the Achilles Tendon Repair Score,
(AS), and the complications were recorded. An elementary cost analysis
was also performed. Between 2008 and 2014 a total of 273 patients presented with
an acute rupture 211 of whom were managed conservatively and 62
had surgical repair. There were three
re-ruptures (1.1%). There were 215 men and 58 women with a mean
age of 46.5 years (20 to 86). Functional outcome was satisfactory.
Mean ATRS and AS at four months was 53.0
( The SMART programme resulted in a low rate of re-rupture, a satisfactory
outcome, a reduced rate of surgical intervention and a reduction
in healthcare costs. Cite this article:
Historically the incidence of Achilles re-ruptures has been described as around 5% after surgical repair and up to 21% after conservative management. In 2008 we commenced a dedicated Achilles tendon rupture clinic for both conservative and surgically managed patients using new standardised operating procedures (SOP). We have evaluated the impact of this new service, particularly with regard to re-rupture rate. The SOP was stage dependent and included an initial ultrasound examination, functional orthotics with early weight bearing, accelerated exercise and guidelines for the return to work and sport. Evaluation included re-rupture rate, complication rate, and outcome measured by the Achilles Tendon Total Rupture Score (ATRS) and Achilles Tendon Repair Score (AS). A basic cost evaluation was performed to assess any potential savings.Introduction:
Materials and methods:
Previous attempts to measure coronal plane patellofemoral kinematics following knee replacement have suffered from methodological drawbacks; the patella being obscured by the components, metal artefact and technical inaccuracies. The aim of this study was to assess whether there was any significant difference in the patellofemoral kinematics between normal, TKR and PFJR patients using the validated MAUS™ technique (combining motion analysis with ultrasound). 60 patients were recruited into three groups; normal healthy volunteers (Normal), TKR, and PFJR patients. The MAUS technique incorporates a 12 camera analysis system (providing gross alignment data for tibial and femoral segments) and an ultrasound probe (providing coordinates of bony landmarks on patella femur and tibia) during a squat exercise. 6 DOF kinematics were described between 0 and 90° flexion. The validated accuracy of the MAUS technique registering the ultrasound images within the motion capture system is 1.84 mm (2 × SD). Movements of the Normal group were significantly different from the TKR group (p=0.03) and the PFJR group (p<0.01), whilst there was no significant difference between the TKR and PFJR groups (p=0.27). Our data suggest that many aspects of patellofemoral kinematics are absent following TKR and PFJR, which could be addressed in future designs of knee TKR and PFJR.
This study examines variations in knee arthroplasty patient reported outcome measures according to patient age. We analysed prospectively collected outcome data (OKS, Eq5D, satisfaction, and revision) on 2456 primary knee arthroplasty patients. Patients were stratified into defined age groups (< 55, 55–64, 65–74, 75–84, and ≥85 years). Oxford Knee Score and Eq5D were analysed pre-operatively, and postoperatively at 6 months and 2 years. Absolute scores and post-operative change in scores were calculated and compared between age groups. Satisfaction scores (0–100) were analysed at 6 months post-operatively. Linear, logistic and ordinal regression modelling was used to describe the association between age and outcomes, for continuous, binary and ordinal outcomes, respectively. Kaplan-Meier analysis was performed to describe revision rates at 2 years.Objectives
Methods
Chronic mid body Achilles A systematic review of the literature was conducted. A search of published and grey literature databases was undertaken (1999- December 2010). Two reviewers independently assessed the studies for eligibility using a strict inclusion and exclusion criteria. All eligible articles were assessed critically using the Pedro score. Data on cohort characteristics, diagnostic criteria, treatment intervention, outcome measures and results was extracted. A narrative research synthesis method was adopted.Introduction
Methods
There is uncertainty about the relationship between improvement in range of motion (ROM) and functional outcome or patient satisfaction after total hip arthroplasty (THA). Using data from a prospective multi-centre study we investigated this relationship. We recorded the Oxford Hip Score (OHS), Merle d'Aubigne and Postel score (MDA) and range of motion (ROM) preoperatively and at one and five years and a patient satisfaction questionnaire at five years. Complete 5 year data were available for 342 patients.Introduction
Methods
We examined data from a large prospectively collected dataset which followed up patients after Exeter total hip replacement (THR) - the Exeter Primary Outcome Study. We studied 78 patients who had total hip replacement for osteoarthritis on a morphologically normal hip, and in whom the other hip was also morphologically normal for comparison. All selected patients had complete patient outcome data at 1 and 5 years, and x-rays at 1 year were available. We measured accuracy of reconstruction on AP Pelvis radiographs. The parameters measured were difference in height of lesser trochanter from horizontal pelvic line (LLD); length from ASIS to greater trochanter (indicating abductor length, AL); length from symphysis to centre of femoral head (SFH); length from centre of head to axis of femur (offset). We examined clinical outcomes including gain of Oxford Hip Score (DOHS) at 1 and 5 years, absolute OHS at 1 and 5 years, and absolute SF-36 Physical Functioning and Role Physical scores at 1 and 5 years. Examining the ratios of AL, SFH, Offset, Offset to SFH ratio and LLD between side of THR and unaffected side all showed marked variation. Thus the ratio of SFH varied from 0.85 to 1.11. For further analysis we divided the patients into 3 groups on the basis of variability of the ratio from 1; we examined whether the clinical scores above varied between these 3 groups. 1 way ANOVA demonstrated no significant difference for any of the clinical outcomes for any of the 5 grouped x-ray variables. Accuracy of reconstruction has been shown to affect the risk of dislocation after THR. Our results indicate that clinical outcomes of total hip replacement appear resilient to some degree of surgical inaccuracy. Future trials of navigation should be designed to demonstrate not only improved accuracy but also improved clinical outcome.
Despite interest, the current rate of day-case anterior cruciate ligament reconstruction (ACLR) in the UK remains low. Although specialised care pathways with standard operating procedures (SOPs) have been effective in reducing length of stay following some surgical procedures, this has not been previously reported for ACLR. We evaluate the effectiveness of SOPs for establishing day-case ACLR in a specialist unit. Fifty patients undergoing ACLR between May and September 2010 were studied prospectively (“study group”). SOPs were designed for pre-operative assessment, anaesthesia, surgical procedure, mobilisation and discharge. We evaluated length of stay, readmission rates, patient satisfaction and compliance to SOPs. A retrospective analysis of 50 patients who underwent ACLR prior to implementation of the day-case pathway was performed (“standard practice group”).Background
Methods
Interest in soft tissue Radiostereometric Analysis (RSA) is rising. Previous authors have tried, with varying levels of success, to use this technique to analyse the intra-substance portion of anterior cruciate ligament (ACL) graft constructs. These methods were either prone to large amounts of marker migration, deemed unsuitable for in-vivo use or, where alternative markers such as stainless steel sutures were used, lost the inherent accuracy that made RSA an attractive tool in the first place. We describe a modification of tantalum marker balls that allows for a new method of secure fixation to soft tissue in order to accurately analyse stretch, displacement and, potentially, dynamic movement using RSA. 1.5 mm tantalum tendon markers were predrilled with 0.3 mm holes, allowing them to be sutured directly to soft tissue. Using a previously described ACL graft model, the amount of marker ball migration was then analysed using RSA after cyclical loading between 20 N and 170 N at 25 Hz for 225,000 cycles.Aims
Methods
Osteoarthritis (OA) of the hip is an important cause of pain and morbidity. The mechanisms and pathogenesis of OA'sdevelopment remain unknown. Minor acetabular dysplasia and subtle variations in proximal femoral morphology are increasingly being recognized as factors that potentially compromise the joint biomechanically and lead to OA. Previous studies have shown that risk of hip OA increased as the femoral head to femoral neck ratio (HNR) decreased. Previous work has described the evolutionary change in inferior femoral neck trabecular density and geometry associated with upright stance, but no study has highlighted the evolutionary change in HNR. The aim of this study was to examine evolutionary evidence that the hominin bipedal stance has lead to alterations in HNR that would predispose humans to hip OA. A collaboration with The Natural History Museums of London, Oxford and the Department of Zoology, University of Oxford provided specimens from the Devonian, Jurassic, Cretaceous, Miocene, Palaeolithic and Pleistocene periods to modern day. Specimens included amphibious reptiles, dinosaurs, shrews, tupaiae, lemurs, African ground apes, Lucy (A. Afarensis), H. Erectus, H. Neaderthalis and humans. Species were grouped according to gait pattern; HAKF (hip and knee flexed), Arboreal (ability to stand with hip and knee joints extended) and hominin/bi-pedal. Imaging of specimens was performed using a 64 slice CT scanner. Three-dimensional skeletal geometries were segmented using MIMICS software. Anatomical measurements from bony landmarks were performed to describe changes in HNR, in the coronal plane of the different specimens over time using custom software. Measurements of HNR from the specimens were compared with HNR measurements made from AP pelvic radiographs of 119 normal subjects and 210 patients with known hip OA listed for hip arthroplasty.Introduction
Methods
Malalignment of some designs of stem is associated with an increased risk of aseptic loosening and revision. We investigated whether the alignment of the cemented polished, double-taper design adversely affected outcome, in a multicentre prospective study. A multicentre prospective study of 1189 total hip replacements was undertaken to investigate whether there is an association between surgical outcome and femoral stem alignment. All patients underwent a primary THR with the Exeter femoral stem (Stryker Howmedica Osteonics, Mahwah, NJ) and a variety of acetabular components. The primary outcome measure was the Oxford hip score (OHS) and change in OHS at five years. Secondary outcomes included rate of dislocation and revision. Radiographic evaluation of the femoral component was also undertaken. The long axis of the Exeter femoral component and the long axis of the femoral canal were located, and the angle at the point of intersection measured. The cementing quality was determined as defined by Barrack et al. Radiolucent lines at the cement-stem and cement-bone interface in the five year radiographs were defined using the zones described by Gruen et al. Subsidence was measured as the vertical dimension of the radiolucency craniolateral to the shoulder of the stem in Gruen zone 1 as described by Fowler et al. Cement fractures were recorded.Introduction
Methods
The options for the treatment of the young active patient with unicompartmental symptomatic osteoarthritis and pre-existing Anterior Cruciate Ligament (ACL) deficiency are limited. Patients with ACL deficiency and end-stage medial compartment osteoarthritis are usually young and active. The Oxford Unicompartmental Knee Replacement (UKA) is a well established treatment option in the management of symptomatic end-stage medial compartmental osteoarthritis, but a functionally intact ACL is a pre-requisite for its satisfactory outcome. If absent, high failure rates have been reported, primarily due to tibial loosening. Previously, we have reported results on a consecutive series of 15 such patients in whom the ACL was reconstructed and patients underwent a staged or simultaneous UKA. The aim of the current study is to provide an update on the clinical and radiological outcomes of a large, consecutive cohort of patients with ACL reconstruction and UKA for the treatment of end-stage medial compartment osteoarthritis and to evaluate, particularly, the outcome of those patients under 50. This study presents a consecutive series of 52 patients with ACL reconstruction and Oxford UKA performed over the past 10 years (mean follow-up 3.4 years). The mean age was 51 years (range: 36–67). Procedures were either carried out as Simultaneous (n=34) or Staged (n=18). Changes in clinical outcomes were measured using the Oxford Knee Score (OKS), the change in OKS (OKS=Post-op − Pre-op) and the American Knee Society Score (AKSS). Fluoroscopy assisted radiographs were taken at each review to assess for evidence of loosening, radiolucency progression, (if present), and component subsidence.Introduction
Methods
Acetabular cup lucency predicts cup survival. The relationship of subchondral plate removal and cup survival is unclear. Using data from a prospective study conducted between January 1999 and January 2002 we investigated the role of subchondral plate removal in cemented acetabular cup survival at five years. A number of cemented cups were implanted using antero-lateral and posterior approaches.1400 cups were inserted. 935 cups (67%) were followed up at 5 years and acetabular radiolucency (AR) recorded.Introduction
Methods
The introduction of hard-on-hard bearings and the consequences of increased wear due to edge-loading have renewed interest in the importance of acetabular component orientation for implant survival and functional outcome following hip arthroplasty. Some studies have shown increased dislocation risk when the cup is mal-oriented which has led to the identification of a safe-zone1. The aims of this prospective, multi-centered study of primary total hip arthroplasty (THA) were to: 1. Identify factors that influence cup orientation and 2. Describe the effect of cup orientation on clinical outcome. In a prospective study involving seven UK centers, patients undergoing primary THA between January 1999 and January 2002 were recruited. All patients underwent detailed assessment pre-operatively as well as post-op. Assessment included data on patient demographics, clinical outcome, complications and further surgery/revision. 681 primary THAs had adequate radiographs for inclusion. 590 hips received cemented cups. The primary functional outcome measure of the study was the change between pre-operative and at latest follow up OHS (OHS). Secondary outcome measures included dislocation rate and revision surgery. EBRA was used to determine acetabular inclination and version. The influence of patient's gender, BMI, surgeon's grade and approach on cup orientation was examined. Four different zones tested as possibly ± (Lewinnek Zone, Callanan's described zone and zones ± 5 and ±10 about the study's mean inclination and anteversion) for a reduced dislocation risk and an optimal functional outcome.INTRODUCTION
METHODS
A femoral head/neck ratio (HNR) of less than 1.27 is associated with an increased risk of arthritis. The aim of this study was to establish whether there is evolutionary evidence that the homonin, bipedal stance has led to alterations in HNR that predispose humans to osteoarthritis (OA). Specimens provided by The Natural History Museums of London, Oxford and the Department of Zoology, University of Oxford were grouped according to gait pattern, HAKF (Hip and knee flexed), Arboreal (ability to stand with hip and knee joints extended) and homonin/bi-pedal. Specimens included those from Devonion, Triassic, Jurrasic, Cretaceous, Miocene, Paleolithic, Pleistocene periods to modern day. Three-dimensional skeletal geometries were segmented using CT images and HNR measurements were taken from coronal views. These were compared with the HNR of 119 asymptomatic human volunteers and 210 patients that had a hip joint replacement for primary OA. Species of the HAKF group had the smallest HNR (1.10, SD:0.09). Species of the Arboreal group had significantly higher HNR (1.63, SD:0.15) in comparison to the Bipedal group (1.41, SD:0.04) (p=0.006), Human (1.33, SD:0.08) and the OA group (1.3, SD:0.09). The range of movement associated with arboreal habitat caused an associated change in HNR. This study would suggest that the HNR peaked in the Miocene period with species that ambulated on both ground and trees. More recent homonin gait appears to have developed a smaller HNR and humans have the smallest amongst their close ancestors. Evolutionary theory would suggest that modern environmental pressures might pre-dispose future hominin evolution to OA, secondary to a further reduction in HNR.
Establishing a full-thickness cartilage in the lateral compartment and functionally intact ACL is vital before proceeding with unicompartmental knee replacement (UKR). The aim of this study is to assess whether MRI is a useful adjunct in predicting suitability for UKR, as compared to standard and stress radiographs. We identified 50 patients with a knee found suitable for UKR based on their standard and stress radiographs (full-thickness cartilage on lateral side). These patients underwent an additional cartilage-specific MRI scan to identify the status of ACL and the lateral compartment. The final decision regarding the suitability for UKR was based on the intra-operative observation.INTRODUCTION
METHODS
Late stage medial unicompartmental osteoarthritic disease of the knee can be treated by either Total Knee Replacement (TKR) or Unicompartmental Replacement (UKR). As a precursor to the TOPKAT study this work tested the postulate that individual surgeons show high variation in the choice of treatment for individual patients. Four surgeons representing four different levels of expertise or familiarity with partial knee replacement (UKR design centre knee surgeon, specialist knee surgeon, arthroplasty surgeon and a year six trainee) made a forced choice decision of whether they would perform a TKR or UKR based on the same pre-operative radiographic and clinical data in 140 individual patients. Consistency of decision was also evaluated for each surgeon 3 months later and the effect of additional clinical data was also evaluated. The sample consisted of the 100 patients who had subsequently undergone UKR and 40 who had undergone TKR.Purpose
Method
To examine the clinical characteristics of patients undergoing knee arthroplasty with a pre-operative Oxford Knee Score >34 (‘good’/‘excellent’), and assess the appropriateness of surgical intervention for this group. In the current cost-constrained health economy, justification of surgical intervention is increasingly sought. As a validated disease-specific outcome measure, the pre-operative Oxford Knee Score (OKS) has been suggested as a possible threshold measurement in knee arthroplasty. However, contrary to expectations, analysis of pre-operative OKS in the joint registry population demonstrates a normal distribution curve with a sub-group of high-scoring patients. This suggests that either the baseline OKS does not accurately define surgical threshold, or that patients with a high OKS are inappropriately having knee replacements.Purpose
Background
The Oxford Knee Score (OKS) is a validated and widely used PROM that has been successfully used in assessing the outcome of knee arthroplasty (KA). It has been adopted as the nationally agreed outcome measure for this procedure and is now routinely collected. Increasingly, it is being used on an individual patient basis as a pre-operative measure of osteoarthritis and the need for joint replacement, despite not being validated for this use. The aim of this paper is to present evidence that challenges this new role for the OKS. We have analysed pre-operative and post-operative OKS data from 3 large cohorts all undergoing KA, totalling over 3000 patients. In addition we have correlated the OKS to patient satisfaction scores. We have validated our findings using data published from the UK NJR.Purpose
Method
The purpose was to determine if the use of cold irrigation fluid in routine knee arthroscopy leads to a reduction in post operative pain. Some surgeons use cooled irrigation fluid in knee arthroscopy in the hope that it may lead to a reduction in post operative pain and swelling. There is currently no evidence for this, although there is some evidence to support the use of cold therapy post operatively in knee surgery.Purpose
Background
Preoperative psychological distress has been reported to predict poor outcome and patient dissatisfaction after total hip replacement (THR). We investigated this relationship in a prospective multi-centre study between January 1999 and January 2002. We recorded the Oxford Hip Score (OHS) and SF36 score preoperatively and up to five years after surgery and a global satisfaction questionnaire at five year follow up for 1039 patients. We dichotomised the patients into the mentally distressed (Mental Health Scale score - MHS <50) and the not mentally distressed (MHS (50) groups based on their pre-operative MHS of the SF36. 776 (677 not distressed and 99 distressed) out of 1039 patients were followed up at 5 years.Introduction
Methods
Anteromedial osteoarthritis of the knee (anteromedial gonarthrosis-AMG) is a common form of knee arthritis. In a clinical setting, knee arthritis has always been assessed by plain radiography in conjunction with pain and function assessments. Whilst this is useful for surgical decision making in bone on bone arthritis, plain radiography gives no insight to the earlier stages of disease. In a recent study 82% of patients with painful arthritis had only partial thickness joint space loss on plain radiography. These patients are managed with various surgical treatments; injection, arthroscopy, osteotomy and arthroplasty with varying results. We believe these varying results are in part due to these patients being at different stages of disease, which will respond differently to different treatments. However radiography cannot delineate these stages. We describe the Magnetic Resonance Imaging (MRI) findings of this partial thickness AMG as a way of understanding these earlier stages of the disease. 46 subjects with symptomatic partial thickness AMG underwent MRI assessment with dedicated 3 Tesla sequences. All joint compartments were scored for both partial and full thickness cartilage lesions, osteophytes and bone marrow lesions (BML). Both menisci were assessed for extrusion and tear. Anterior cruciate ligament (ACL) integrity was also assessed. Osteophytes were graded on a four point scale in the intercondylar notch and the lateral margins of the joint compartments. Scoring was performed by a consultant radiologist and clinical research fellow using a validated MRI atlas with consensus reached for disagreements. The results were tabulated and relationships of the interval data assessed with linear by linear Chi2 test and Pearson's Correlation.Introduction
Method
Anteromedial gonarthrosis is a common well described pattern of knee osteoarthritis with cartilage wear beginning in the anteromedial quadrant of the medial tibial plateau in the presence of an intact and functioning ACL. It is well known that mechanical factors such as limb alignment and meniscal integrity affect the progression of arthritis and there is some evidence that the morphology of the tibial plateau may be a risk factor in the development of this disease. The extension facet angle is the angle of the downslope of the anterior portion of the medial tibial plateau joint surface in relation to the middle portion on a sagittal view. If this is an important factor in the development of AMG there may be potential for disease modifying intervention. This study investigates if there is a significant difference in this angle as measured on MRI between a study cohort with early AMG (partial thickness cartilage damage and intact ACL) and a comparator control cohort of patients (no cartilage damage and ACL rupture). 3 Tesla MRI scans of 99 patients; 54 with partial thickness cartilage damage and 44 comparitors with no cartilage damage (acute ACL rupture) were assessed. The extension facet angle was measured (Osirix v3.6) using a validated technique on two consecutive MRI T2 sagittal slices orientated at the mid-coronal point of the medial femoral condyle. (InterClass Correlation 0.95, IntraClass Correlation 0.97, within subject variation of 1.1° and coefficient of variation 10.7%). The mean of the two extension angle values was used. The results were tabulated and analysed (R v2.9.1).Introduction
Methods
The heat produced by drills, saws and PMMA cement in the handling of bone can cause thermal necrosis. Thermal necrosis could be a factor in the formation of a fibrous tissue membrane and impaired bony ingrowth into porous prostheses. This has been proposed to lead to non-union of osteotomies and fractures, the failure of the bone-cement interface and the failure of resurfacing arthroplasty. We compared three proprietary blades (the De Soutter, the Stryker Dual Cut and the Stryker Precision) in an in-vitro setting with porcine tibiae, using thermocouples embedded in the bone below the cutting surface to measure the increases in bone temperature. There was a significant (p=0.001) difference in the change in temperature (δT) between the blade types. The mean increase in temperature was highest for the De Soutter, 2.84°C (SD: 1.83°C, range 0.48°C to 9.30°C); mean δT was 1.81°C (SD: 1.00°C, range 0.18°C to 4.85°C) for the Precision and 1.68°C (SD: 0.95°C, range 0.24°C to 5.67°C). Performing paired tests, there was no significant difference in δT between the Precision and Dual Cut blades (p=0.340), but both these blades had significantly (p=0.003 for Precision vs De Soutter, p<0.001 for Dual Cut vs De Soutter) lower values for δT than the Dual Cut.
The results of the mobile bearing Oxford unicompartmental knee replacement (UKR) in the lateral compartment have been disappointing with a five year survival of 82%. Therefore, it is recommended that mobile bearings should not be used for lateral UKR. This low survivorship is primarily due to high dislocation rate, all occurring in the first year. A detailed analysis of the causes of bearing dislocation confirmed the elevated lateral tibial joint line to be a contributory factor. A new surgical technique was therefore introduced in which care was taken neither to remove too much bone from distal femur nor to over tighten the knee and thus ensure that the tibial joint line was not elevated. Other modifications to the technique were also introduced including use of a domed tibial component. The aim of this study is to compare the outcome of these iterations: the original series [series I], Series II with improved surgical technique and the domed tibial component [Series III].Introduction
Aim
Total knee arthroplasty (TKA) accounts for 84% of all knee replacement surgery in the UK (NJR 2009) despite published epidemiological data showing that single compartment disease is most prevalent. We investigated this incompatibility further by describing the compartmental pattern and stage of cartilage loss of all patients with osteoarthritis (OA) presenting to a specialist knee clinic over one year. All new primary referrals in a calendar year by local General Practitioners to knee clinic at a United Kingdom Hospital were assessed. Tertiary referrals and second opinions were excluded. The final diagnosis after all imaging was recorded and tabulated. The standing AP, lateral and skyline radiographs of all cases of arthritis were scored to assess the pattern of disease.Introduction
Methods
We obtained information from the Elective Orthopaedic
Centre on 1523 patients with baseline and six-month Oxford hip scores
(OHS) after undergoing primary hip replacement (THR) and 1784 patients
with Oxford knee scores (OKS) for primary knee replacement (TKR)
who completed a six-month satisfaction questionnaire. Receiver operating characteristic curves identified an absolute
change in OHS of 14 points or more as the point that discriminates
best between patients’ satisfaction levels and an 11-point change
for the OKS. Satisfaction is highest (97.6%) in patients with an
absolute change in OHS of 14 points or more, compared with lower
levels of satisfaction (81.8%) below this threshold. Similarly,
an 11-point absolute change in OKS was associated with 95.4% satisfaction
compared with 76.5% below this threshold. For the six-month OHS
a score of 35 points or more distinguished patients with the highest
satisfaction level, and for the six-month OKS 30 points or more identified
the highest level of satisfaction. The thresholds varied according
to patients’ pre-operative score, where those with severe pre-operative
pain/function required a lower six-month score to achieve the highest
levels of satisfaction. Our data suggest that the choice of a six-month follow-up to
assess patient-reported outcomes of THR/TKR is acceptable. The thresholds
help to differentiate between patients with different levels of
satisfaction, but external validation will be required prior to
general implementation in clinical practice.
To assess the incidence of radiolucency in cemented and cementless Oxford unicompartmental knee replacement at two years. Most unicompartmental knee replacements (UKRs) employ cement for fixation of the prosthetic components. The information in the literature about the relative merits of cemented and cementless UKR is contradictory, with some favouring cementless fixation and others favouring cemented fixation. In addition, there is concern about the radiolucency that frequently develops beneath the tibial component with cemented fixation. The exact cause of the occurrence of radiolucency is unknown but it has been hypothesised that it may suggest suboptimal fixation.Purpose of Study
Introduction
This study aims to investigate femoral blood flow during Metal-on-Metal Hip Resurfacing (MMHR) by monitoring oxygen concentration during the operative procedure. Patients undergoing MMHR using the posterior approach were evaluated. Following division of fascia lata, a calibrated gas-measuring electrode was inserted into the femoral neck, aiming for the supero-lateral quadrant of the head. Baseline oxygen concentration levels were detected after electrode insertion 2-3cm below the femoral head surface and all intra-operative measures were referenced against these. Oxygen levels were continuously monitored throughout the operation. Data from ten patients are presented. Oxygen concentration dropped most noticeably during the surgical approach and was reduced by 62% (Std.dev +/-26%) following dislocation and capsulectomy. Insertion of implants resulted in a further oxygenation decrease by 18% (Std.dev +/-28%). The last obtained measure before wound closure detected 22% (Std.dev +/-31%) of initial baseline oxygen levels. Variation between subjects was observed and three patients demonstrated a limited recovery of oxygen levels during implant insertion and hip relocation. Intra-operative measurement of oxygen concentration in blood perfusing the femoral head is feasible. Results in ten patients undergoing MMHR showed a dramatic effect on the oxygenation in the femoral head during surgical approach and implant fixation. This may increase the risk of avascular necrosis and subsequent femoral neck fracture. Future experiments will determine if less invasive procedures or specific positioning of the limb can protect the blood supply to femoral neck and head.
We obtained pre-operative and six-month post-operative
Oxford hip (OHS) and knee scores (OKS) for 1523 patients who underwent
total hip replacement and 1784 patients who underwent total knee
replacement. They all also completed a six-month satisfaction question. Scatter plots showed no relationship between pre-operative Oxford
scores and six-month satisfaction scores. Spearman’s rank correlation
coefficients were -0.04 (95% confidence interval (CI) -0.09 to 0.01)
between OHS and satisfaction and 0.04 (95% CI -0.01 to 0.08) between
OKS and satisfaction. A receiver operating characteristic (ROC) curve
analysis was used to identify a cut-off point for the pre-operative
OHS/OKS that identifies whether or not a patient is satisfied with
surgery. We obtained an area under the ROC curve of 0.51 (95% CI
0.45 to 0.56) for hip replacement and 0.56 (95% CI 0.51 to 0.60)
for knee replacement, indicating that pre-operative Oxford scores
have no predictive accuracy in distinguishing satisfied from dissatisfied
patients. In the NHS widespread attempts are being made to use patient-reported
outcome measures (PROMs) data for the purpose of prioritising patients
for surgery. Oxford hip and knee scores have no predictive accuracy
in relation to post-operative patient satisfaction. This evidence
does not support their current use in prioritising access to care.
This study investigates if there is a significant difference in this angle as measured on MRI between a study cohort with early AMG (partial thickness cartilage damage and intact ACL) and a comparator control cohort of patients (no cartilage damage and ACL rupture).
8 MoMHRA implants revised due to pseudotumour; 22 MoMHRA implants revised due to other reasons of failure (femoral neck fracture and infection). The linear wear of retrieved implants was measured using a Taylor-Hobson Roundness machine. The average linear wear rate was defined as the maximum linear wear depth divided by the duration of the implant in vivo.
significantly higher median linear wear rate of the femoral component: 8.1um/year (range 2.75–25.4um/year) vs. 1.79um/year (range 0.82–4.15um/year), p=0.002; and significantly higher median linear wear rate of the acetabular component: 7.36um/year (range1.61–24.9um/year) vs. 1.28um/year (range 0.18–3.33um/year), p=0.001. Similarly, differences were also measured in absolute wear values. The median absolute linear wear was significantly higher in the pseudotumour implant group:
21.05um (range 2.74–164.80um) vs. 4.44um (range 1.50–8.80um) for the femoral component, p=0.005; and 14.87um (range 1.93–161.68um) vs. 2.51um (range 0.23–6.04um) for the acetabular component, p=0.008. Wear on the acetabular cup components in the pseudotumour group always involved the edge, indicating edge-loading of the bearing. In contrast, edge-loading was observed in only one acetabular component in the non-pseudotumour group of implants. The deepest wear was observed well within the bearing surface for the rest of the non-pseudotumour group. The difference in the incidence of edge-loading between the two groups was statistically significant (Fisher’s exact test, p=0.03).
The results of mobile bearing Oxford unicompartmental knee replacement (UKR) in the lateral compartment have been disappointing (five-year survival: 82%). Therefore, it is recommended that mobile bearings should not be used for lateral UKR. This low survivorship is primarily due to a high dislocation rate. A detailed analysis confirmed the elevated lateral tibial joint line to be a contributory factor to bearing dislocation. A new surgical technique was therefore introduced in which care was taken neither to remove too much bone from the distal femur nor to over tighten the knee and therefore ensure that the tibial joint line was not elevated. Other modifications included use of a domed tibial component. The aim of this study is to compare the outcome of these iterations: the original series (series I), those with improved surgical technique (series II) and the domed tibial component (series III). The primary outcome measure was bearing dislocation at one year. One year was chosen as all the dislocations in the first series occurred within a year. In the original series (n=53), implanted using a standard open approach, there were six dislocations in the first year, the average flexion 110°, and 95% had no/mild pain on activity. In the second series (n=65), there were 3 dislocations, the average flexion was 117°, and 80% had no/mild pain on activity. In the third series with the modified technique and a convex domed tibial plateau, there was one dislocation, average flexion was 125° and 94% had no/mild pain on activity. At four years the cumulative primary dislocation rates were 10%, 5% and 0% respectively, and were significantly different (p=0.04). The improved surgical technique and implant design has reduced dislocation rate to an acceptable level so a mobile bearing can now be recommended for lateral UKR.
Roentgen Stereophotogrammetric Analysis (RSA) can predict long-term outcome of prostheses by measuring migration over time. The Exeter femoral stem is a double-tapered highly polished implant and has been shown to subside within the cement mantle in 2 year RSA studies. It has a proven track record in terms of long-term survivorship and low revision rates. Several studies have demonstrated excellent clinical outcomes following its implantation but this is the first study to assess stem migration at 10 years, using RSA. This is a single-centre study involving 20 patients (mean age: 63 years, SD=7) undergoing primary total hip replacement for degenerative osteoarthritis using the lateral (Hardinge) approach. RSA radiographs were taken with the patient bearing full weight post-operatively, at 3, 6, 12 months and at 2, 5 and 10 years follow-up. The three-dimensional migration of the Exeter femoral stem was determined. The mean Oxford Hip Score at 10 years was 43.4 (SD=4.6) and there were no revisions. The stems subsided and rotated internally during a 10-year period. The mean migrations of the head and tip of the femoral stem in all three anatomic directions (antero-posterior, medio-lateral &
supero-distal) were 0.69 mm posterior, 0.04 mm lateral and 1.67 mm distal for the head and 0.20 mm anterior, 0.02 mm lateral and 1.23 mm distal for the tip. The total migration at 10 years was 1.81 mm for the head and 1.25 mm for the tip. The Exeter femoral stem exhibits migration which is a complex combination of translation and rotation in three dimensions. Comparing our 10 year with our previous 2 year migration results, the Exeter stems show continued, but slow distal migration and internal rotation. The subsidence continues to compress the cement and bone-cement interface which maintains secure fixation in the long term.
About ten years ago we introduced sophisticated instrumentation and an increased range of component sizes for the Oxford unicompartmental knee replacement (UKR) to facilitate a minimally invasive surgical (MIS) approach. The device is now routinely implanted through an incision from the medial pole of the patella to the tibial tuberosity. This has resulted in a more rapid recovery and an improved functional result. As the access to the knee is limited there is a concern that the long term results may be compromised. The aim of this study was to determine the 10 year survival. A prospective follow up of all Phase 3 minimally invasive Oxford UKR implanted by two senior authors (DWM &
CAFD) has been undertaken. So far 1015 UKRs have been implanted for anteromedial osteoarthritis. All patients received a cemented implant through a MIS approach and were followed up prospectively by an independent observer. The data was collected prospectively regarding pre-operative status, complications and clinical as well as functional outcome at predetermined intervals. The average age of patients was 66.4 years (range: 33 – 88) with mean Oxford Knee Score 41 (SD: 7.9) at the time of last follow up, Knee Society Score (objective) of 84 (SD: 13) and Knee Society Score (functional) of 83 (SD: 21). At ten years the survival of this cohort is 96%. There were 22 revisions including 7 for progression of arthritis, 5 for infection, 5 for bearing dislocation, 4 for unexplained pain and one for rupture of ACL secondary to trauma. We conclude that the Oxford Knee can be implanted reliably through a minimally invasive approach, giving excellent long term results.
90% of lateral compartments were normal and none had full thickness cartilage loss. However 10% showed high signal in the tibial plateau. There was a highly reproducible pattern of osteophyte formation; 94% posteromedial and posterolateral aspect of medial femoral condyle; 90% medial tibial; 80% medial femoral and 84% lateral intercondylar notch.
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.
Patello-femoral instability (PFI) affects 40 individuals per 100,000 population and causes significant morbidity. The causes of patello-femoral instability are multi-factorial, and an isolated anatomical abnormality does not necessarily indicate instability. Patello-femoral subluxation ranges from 0% (stable patella tracking) to 100% (dislocation) and there is an established relationship between the amount of subluxation and anterior knee pain. Traditionally, magnetic resonance (MR) imaging and standard radiographs are used to guide the clinician towards a suitable corrective procedure for PFI. The multi-factorial nature of patello-femoral instability is not addressed with current imaging techniques. This study aims to address which anatomical variables assessed on MR images are most relevant to patello-femoral subluxation. This information will aid surgical decision making, particularly in selecting the most appropriate reconstructive surgery. A retrospective analysis of MR studies of 60 patients with suspected patello-femoral instability was performed. All patients were graded for degree of subluxation using a dynamic MR scan. The patient scans were assessed for the presence of a specific range of anatomical variables:
patella alta, (modified Insall-Salvatti) patella type (Wiberg classification) trochlea sulcus angles for bone and cartilage surfaces the distance of the vastus medialis obliquis (VMO) muscle from the patella trochlea and patella cartilage thickness the horizontal distance between the tibial tubercle and the midpoint of the femoral trochlea (TTD) patella engagement – the percentage of the patella height that is captured in the trochlea groove in full extension. The Wilk’s Lambda test for multi-variate analysis was used to establish whether any relationship was present between the degree of patello-femoral instability and bony or soft tissue anatomical variables. Non-parametric statistical tests were applied across the groups and within the groups to assess their relative significance. The following variables showed a significant relationship with patellofemoral subluxation; distance of the VMO from the patella (<
0.001), TTD (<
0.001), patella engagement (0.001), sulcus angles (0.004) and patella alta (0.005). This study agrees with previous work showing a significant correlation between subluxation and trochlea sulcus angle and TTD. This is the first study to establish a significant correlation between patella engagement and radiological instability. The lower the percentage engagement of the patella in the trochlea, the greater the degree of patello-femoral instability. Patella engagement showed a more significant relationship with subluxation than patella alta. We report a new method of predicting patello-femoral instability by measuring the overlap of the patella in the trochlea groove.