Aims

The aim was to assess whether robotic-assisted total knee arthroplasty (rTKA) had greater knee-specific outcomes, improved fulfilment of expectations, health-related quality of life (HRQoL), and patient satisfaction when compared with manual TKA (mTKA).

Aims

Achievement of accurate microbiological diagnosis prior to revision is key to reducing the high rates of persistent infection after revision knee surgery. The effect of change in the microorganism between the first- and second-stage revision of total knee arthroplasty for periprosthetic joint infection (PJI) on the success of management is not clear.

Aims

The primary aim was to assess whether robotic total knee arthroplasty (rTKA) had a greater early knee-specific outcome when compared to manual TKA (mTKA). Secondary aims were to assess whether rTKA was associated with improved expectation fulfilment, health-related quality of life (HRQoL), and patient satisfaction when compared to mTKA.

Aims

The aim of this study was to identify variables associated with time to revision, demographic details associated with revision indication, and type of prosthesis employed, and to describe the survival of hinge knee arthroplasty (HKA) when used for first-time knee revision surgery and factors that were associated with re-revision.

Aims

The primary aim of our study was to assess the influence of age on hip-specific outcome following total hip arthroplasty (THA). Secondary aims were to assess health-related quality of life (HRQoL) and level of activity according to age.

Aims

The primary aim was to assess the rate of postoperative COVID-19 following hip and knee arthroplasty performed in March 2020 in the UK. The secondary aims were to assess whether there were clinical factors associated with COVID-19 status, the mortality rate of patients with COVID-19, and the rate of potential COVID-19 in patients not presenting to healthcare services.

Aims

The aim of this study was to assess the quality of life of patients on the waiting list for a total hip (THA) or knee arthroplasty (KA) during the COVID-19 pandemic. Secondary aims were to assess whether length of time on the waiting list influenced quality of life and rate of deferral of surgery.

Aims

The primary aim is to estimate the current and potential number of patients on NHS England orthopaedic elective waiting lists by November 2020. The secondary aims are to model recovery strategies; review the deficit of hip and knee arthroplasty from National Joint Registry (NJR) data; and assess the cost of returning to pre-COVID-19 waiting list numbers.

Aims

The primary aim of this study was to assess whether the postoperative Oxford Knee Score (OKS) demonstrated a ceiling effect at one and/or two years after total knee arthroplasty (TKA). The secondary aim was to identify preoperative independent predictors for patients that achieved a ceiling score after TKA.

Aims

The primary aim was to assess the rate of patient deferral of elective orthopaedic surgery and whether this changed with time during the coronavirus disease 2019 (COVID-19) pandemic. The secondary aim was to explore the reasons why patients wanted to defer surgery and what measures/circumstances would enable them to go forward with surgery.

Aims

Stiffness is a common complication after total knee arthroplasty (TKA). Pathogenesis is not understood, treatment options are limited, and diagnosis is challenging. The aim of this study was to investigate if MRI can be used to visualize intra-articular scarring in patients with stiff, painful knee arthroplasties.

Aims

The primary aim of this study was to assess whether pain in the contralateral knee had a clinically significant influence on the outcome of total knee arthroplasty (TKA) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Secondary aims were to: describe the prevalence of contralateral knee pain; identify if it clinically improves after TKA; and assess whether contralateral knee pain independently influences patient satisfaction with their TKA.

Aims

The primary aim of the study was to perform an analysis to identify the cost per quality-adjusted life-year (QALY) of robot-assisted unicompartmental knee arthroplasty (rUKA) relative to manual total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) for patients with isolated medial compartment osteoarthritis (OA) of the knee. Secondary aims were to assess how case volume and length of hospital stay influenced the relative cost per QALY.

Objectives

Our primary aim was to describe migration of the Exeter stem with a 32 mm head on highly crosslinked polyethylene and whether this is influenced by age. Our secondary aims were to assess functional outcome, satisfaction, activity, and bone mineral density (BMD) according to age.

Aims

The primary aim of this study was to assess the rate of patient satisfaction one year after total knee arthroplasty (TKA) according to the focus of the question asked. The secondary aims were to identify independent predictors of patient satisfaction according to the focus of the question.

Aims

The primary aim of this study was to assess whether patient satisfaction one year after total knee arthroplasty (TKA) changed with longer follow-up. The secondary aims were to identify predictors of satisfaction at one year, persistence of patient dissatisfaction, and late onset dissatisfaction in patients that were originally satisfied at one year.

Aims

The aim of this consensus was to develop a definition of post-operative fibrosis of the knee.

The aim of this study was to compare the maximum laxity conferred by the cruciate-retaining (CR) and posterior-stabilised (PS) Triathlon single-radius total knee arthroplasty (TKA) for anterior drawer, varus–valgus opening and rotation in eight cadaver knees through a defined arc of flexion (0º to 110º). The null hypothesis was that the limits of laxity of CR- and PS-TKAs are not significantly different.

The investigation was undertaken in eight loaded cadaver knees undergoing subjective stress testing using a measurement rig. Firstly the native knee was tested prior to preparation for CR-TKA and subsequently for PS-TKA implantation. Surgical navigation was used to track maximal displacements/rotations at 0º, 30º, 60º, 90º and 110° of flexion. Mixed-effects modelling was used to define the behaviour of the TKAs.

The laxity measured for the CR- and PS-TKAs revealed no statistically significant differences over the studied flexion arc for the two versions of TKA. Compared with the native knee both TKAs exhibited slightly increased anterior drawer and decreased varus-valgus and internal-external roational laxities. We believe further study is required to define the clinical states for which the additional constraint offered by a PS-TKA implant may be beneficial.

Cite this article: Bone Joint J 2015; 97-B:642–8.

The National Institute for Health and Clinical Excellence (NICE) has thus far relied on historical data and predominantly industry-sponsored trials to provide evidence for venous thromboembolic (VTE) prophylaxis in joint replacement patients. We argue that the NICE guidelines may be reliant on assumptions that are in need of revision. Following the publication of large scale, independent observational studies showing little difference between low-molecular-weight heparins and aspirin, and recent changes to the guidance provided by other international bodies, should NICE reconsider their recommendations?

Cite this article: Bone Joint Res 2014;3:146–9.

Pre-operative variables are increasingly being used to determine eligibility for total knee replacement (TKR). This study was undertaken to evaluate the relationships, interactions and predictive capacity of variables available pre- and post-operatively on patient satisfaction following TKR. Using nationally collected patient reported outcome measures and data from the National Joint Registry for England and Wales, we identified 22 798 patients who underwent TKR for osteoarthritis between August 2008 and September 2010. The ability of specific covariates to predict satisfaction was assessed using ordinal logistic regression and structural equational modelling. Only 4959 (22%) of 22 278 patients rated the results of their TKR as ‘excellent’, despite the majority (71%, n = 15 882) perceiving their knee symptoms to be much improved. The strongest predictors of satisfaction were post-operative variables. Satisfaction was significantly and positively related to the perception of symptom improvement (operative success) and the post-operative EuroQol-5D score. While also significant within the models pre-operative variables were less important and had a minimal influence upon post-operative satisfaction. The most robust predictions of satisfaction occurred only when both pre- and post-operative variables were considered together. These findings question the appropriateness of restricting access to care based on arbitrary pre-operative thresholds as these factors have little bearing on post-operative satisfaction.

Cite this article: Bone Joint J 2013;95-B:1359–65.

The popularity of cementless total hip replacement (THR) has surpassed cemented THR in England and Wales. This retrospective cohort study records survival time to revision following primary cementless THR with the most common combination (accounting for almost a third of all cementless THRs), and explores risk factors independently associated with failure, using data from the National Joint Registry for England and Wales. Patients with osteoarthritis who had a DePuy Corail/Pinnacle THR implanted between the establishment of the registry in 2003 and 31 December 2010 were included within analyses. There were 35 386 procedures. Cox proportional hazard models were used to analyse the extent to which the risk of revision was related to patient, surgeon and implant covariates. The overall rate of revision at five years was 2.4% (99% confidence interval 2.02 to 2.79). In the final adjusted model, we found that the risk of revision was significantly higher in patients receiving metal-on-metal (MoM: hazard ratio (HR) 1.93, p < 0.001) and ceramic-on-ceramic bearings (CoC: HR 1.55, p = 0.003) compared with the best performing bearing (metal-on-polyethylene). The risk of revision was also greater for smaller femoral stems (sizes 8 to 10: HR 1.82, p < 0.001) compared with mid-range sizes. In a secondary analysis of only patients where body mass index (BMI) data were available (n = 17 166), BMI ≥ 30 kg/m² significantly increased the risk of revision (HR 1.55, p = 0.002). The influence of the bearing on the risk of revision remained significant (MoM: HR 2.19, p < 0.001; CoC: HR 2.09, p = 0.001). The risk of revision was independent of age, gender, head size and offset, shell, liner and stem type, and surgeon characteristics.

We found significant differences in failure between bearing surfaces and femoral stem size after adjustment for a range of covariates in a large cohort of single-brand cementless THRs. In this study of procedures performed since 2003, hard bearings had significantly higher rates of revision, but we found no evidence that head size had an effect. Patient characteristics, such as BMI and American Society of Anesthesiologists grade, also influence the survival of cementless components.

Cite this article: Bone Joint J 2013;95-B:747–57.

Current analysis of unicondylar knee replacements (UKRs) by national registries is based on the pooled results of medial and lateral implants. Consequently, little is known about the differential performance of medial and lateral replacements and the influence of each implant type within these pooled analyses. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of UKRs implanted on the lateral side of the knee, and their survival and reason for failure compared with medial UKRs. By combining information on the side of operation with component details held on the NJR, we were able to determine implant laterality (medial versus lateral) for 32 847 of the 35 624 unicondylar replacements (92%) registered before December 2010. Of these, 2052 (6%) were inserted on the lateral side of the knee. The rates of survival at five years were 93.1% (95% confidence interval (CI) 92.7 to 93.5) for medial and 93.0% (95% CI 91.1 to 94.9) for lateral UKRs (p = 0.49). The rates of failure remained equivalent after adjusting for patient age, gender, American Society of Anesthesiologists (ASA) grade, indication for surgery and implant design using Cox’s proportional hazards method (hazard ratio for lateral relative to medial replacement = 0.88 (95% CI 0.69 to 1.13); p = 0.32). Aseptic loosening/lysis and unexplained pain were the main reasons for revision in both groups, although the reasons did vary depending on whether a mobile- or a fixed-bearing design was used. At a maximum of eight years the mid-term survival rates of medial and lateral UKRs are similar.

Despite excellent results, the use of cemented total hip replacement (THR) is declining. This retrospective cohort study records survival time to revision following primary cemented THR using the most common combination of components that accounted for almost a quarter of all cemented THRs, exploring risk factors independently associated with failure. All patients with osteoarthritis who had an Exeter V40/Contemporary THR (Stryker) implanted before 31 December 2010 and recorded in the National Joint Registry for England and Wales were included in the analysis. Cox’s proportional hazard models were used to analyse the extent to which risk of revision was related to patient, surgeon and implant covariates, with a significance threshold of p < 0.01. A total of 34 721 THRs were included in the study. The overall seven-year rate of revision for any reason was 1.70% (99% confidence interval (CI) 1.28 to 2.12). In the final adjusted model the risk of revision was significantly higher in THRs with the Contemporary hooded component (hazard ratio (HR) 1.88, p < 0.001) than with the flanged version, and in smaller head sizes (< 28 mm) compared with 28 mm diameter heads (HR 1.50, p = 0.005). The seven-year revision rate was 1.16% (99% CI 0.69 to 1.63) with a 28 mm diameter head and flanged component. The overall risk of revision was independent of age, gender, American Society of Anesthesiologists grade, body mass index, surgeon volume, surgical approach, brand of cement/presence of antibiotic, femoral head material (stainless steel/alumina) and stem taper size/offset. However, the risk of revision for dislocation was significantly higher with a ‘plus’ offset head (HR 2.05, p = 0.003) and a hooded acetabular component (HR 2.34, p < 0.001).

In summary, we found that there were significant differences in failure between different designs of acetabular component and sizes of femoral head after adjustment for a range of covariates.

United Kingdom National Institute for Health and Clinical Excellence guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractures of the femoral neck in cognitively intact patients, who were independently mobile prior to the injury. This study aimed to analyse the risk factors associated with revision of the implant and mortality following THR, and to quantify risk. National Joint Registry data recording a THR performed for acute fracture of the femoral neck between 2003 and 2010 were analysed. Cox proportional hazards models were used to investigate the extent to which risk of revision was related to specific covariates. Multivariable logistic regression was used to analyse factors affecting peri-operative mortality (< 90 days). A total of 4323 procedures were studied. There were 80 patients who had undergone revision surgery at the time of censoring (five-year revision rate 3.25%, 95% confidence interval 2.44 to 4.07) and 137 patients (3.2%) patients died within 90 days. After adjusting for patient and surgeon characteristics, an increased risk of revision was associated with the use of cementless prostheses compared with cemented (hazard ratio (HR) 1.33, p = 0.021). Revision was independent of bearing surface and head size. The risk of mortality within 90 days was significantly increased with higher American Society of Anesthesiologists (ASA) grade (grade 3: odds ratio (OR) 4.04, p < 0.001; grade 4/5: OR 20.26, p < 0.001; both compared with grades 1/2) and older age (≥ 75 years: OR 1.65, p = 0.025), but reduced over the study period (9% relative risk reduction per year).

THR is a good option in patients aged < 75 years and with ASA 1/2. Cementation of the femoral component does not adversely affect peri-operative mortality but improves survival of the implant in the mid-term when compared with cementless femoral components. There are no benefits of using head sizes > 28 mm or bearings other than metal-on-polyethylene. More research is required to determine the benefits of THR over hemiarthroplasty in older patients and those with ASA grades > 2.

Patient-reported outcome measures (PROMs) are increasingly being used to assess functional outcome and patient satisfaction. They provide a framework for comparisons between surgical units, and individual surgeons for benchmarking and financial remuneration. Better performance may bring the reward of more customers as patients and commissioners seek out high performers for their elective procedures. Using National Joint Registry (NJR) data linked to PROMs we identified 22 691 primary total knee replacements (TKRs) undertaken for osteoarthritis in England and Wales between August 2008 and February 2011, and identified the surgical factors that influenced the improvements in the Oxford knee score (OKS) and EuroQol-5D (EQ-5D) assessment using multiple regression analysis. After correction for patient factors the only surgical factors that influenced PROMs were implant brand and hospital type (both p < 0.001). However, the effects of surgical factors upon the PROMs were modest compared with patient factors. For both the OKS and the EQ-5D the most important factors influencing the improvement in PROMs were the corresponding pre-operative score and the patient’s general health status. Despite having only a small effect on PROMs, this study has shown that both implant brand and hospital type do influence reported subjective functional scores following TKR. In the current climate of financial austerity, proposed performance-based remuneration and wider patient choice, it would seem unwise to ignore these effects and the influence of a range of additional patient factors.

Purpose

Little information is available relating to patient demographics, reasons for failure and types of implants used at time of revision following failure of patellofemoral joint (PFJ) replacement.

Following arthroplasty of the knee, the patient’s perception of improvement in symptoms is fundamental to the assessment of outcome. Better clinical outcome may offset the inferior survival observed for some types of implant. By examining linked National Joint Registry (NJR) and patient-reported outcome measures (PROMs) data, we aimed to compare PROMs collected at a minimum of six months post-operatively for total (TKR: n = 23 393) and unicondylar knee replacements (UKR: n = 505). Improvements in knee-specific (Oxford knee score, OKS) and generic (EuroQol, EQ-5D) scores were compared and adjusted for case-mix differences using multiple regression. Whereas the improvements in the OKS and EQ-5D were significantly greater for TKR than for UKR, once adjustments were made for case-mix differences and pre-operative score, the improvements in the two scores were not significantly different. The adjusted mean differences in the improvement of OKS and EQ-5D were 0.0 (95% confidence interval (CI) -0.9 to 0.9; p = 0.96) and 0.009 (95% CI -0.034 to 0.015; p = 0.37), respectively.

We found no difference in the improvement of either knee-specific or general health outcomes between TKR and UKR in a large cohort of registry patients. With concerns about significantly higher revision rates for UKR observed in worldwide registries, we question the widespread use of an arthroplasty that does not confer a significant benefit in clinical outcome.

We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or low-molecular-weight heparin (LMWH). Data from the National Joint Registry for England and Wales were linked to an administrative database of hospital admissions in the English National Health Service. A total of 156 798 patients between April 2003 and September 2008 were included and followed 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. In all, 36 159 patients (23.1%) were prescribed aspirin and 120 639 patients (76.9%) were prescribed LMWH. We found no statistically significant differences between the aspirin and LMWH groups in the rate of pulmonary embolism (0.49% vs 0.45%, AOR 0.88 (95% confidence interval (CI) 0.74 to 1.05); p = 0.16), 90-day mortality (0.39% vs 0.45%, AOR 1.13 (95% CI 0.94 to 1.37); p = 0.19) or major haemorrhage (0.37% vs 0.39%, AOR 1.01 (95% CI 0.83 to 1.22); p = 0.94). There was a significantly greater likelihood of needing to return to theatre in the aspirin group (0.26% vs 0.19%, AOR 0.73 (95% CI 0.58 to 0.94); p = 0.01). Between patients receiving LMWH or aspirin there was only a small difference in the risk of pulmonary embolism, 90-day mortality and major haemorrhage.

These results should be considered when the existing guidelines for thromboprophylaxis after knee replacement are reviewed.

Modern metal-on-metal hip resurfacing has been widely performed in the United Kingdom for over a decade. However, the literature reports conflicting views of the benefits: excellent medium- to long-term results with some brands in specific subgroups, but high failure rates and local soft-tissue reactions in others. The National Joint Registry for England and Wales (NJR) has collected data on all hip resurfacings performed since 2003. This retrospective cohort study recorded survival time to revision from a resurfacing procedure, exploring risk factors independently associated with failure. All patients with a primary diagnosis of osteoarthritis who underwent resurfacing between 2003 and 2010 were included in the analyses. Cox’s proportional hazard models were used to analyse the extent to which the risk of revision was related to patient, surgeon and implant covariates.

A total of 27 971 hip resurfacings were performed during the study period, of which 1003 (3.59%) underwent revision surgery. In the final adjusted model, we found that women were at greater risk of revision than men (hazard ratio (HR) = 1.30, p = 0.007), but the risk of revision was independent of age. Of the implant-specific predictors, five brands had a significantly greater risk of revision than the Birmingham Hip Resurfacing (BHR) (ASR: HR = 2.82, p < 0.001, Conserve: HR = 2.03, p < 0.001, Cormet: HR = 1.43, p = 0.001, Durom: HR = 1.67, p < 0.001, Recap: HR = 1.58, p = 0.007). Smaller femoral head components were also significantly more likely to require revision (≤ 44 mm: HR = 2.14, p < 0.001, 45 to 47 mm: HR = 1.48, p = 0.001) than medium or large heads, as were operations performed by low-volume surgeons (HR = 1.36, p <  0.001). Once these influences had been removed, in 4873 male patients < 60 years old undergoing resurfacing with a BHR, the five-year estimated risk of revision was 1.59%.

In summary, after adjustment for a range of covariates we found that there were significant differences in the rate of failure between brands and component sizes. Younger male patients had good five-year implant survival when the BHR was used.

Arthroscopy of the knee is one of the most commonly performed orthopaedic procedures worldwide. Large-volume outcome data have not previously been available for English NHS patients. Prospectively collected admissions data, routinely collected on every English NHS patient, were analysed to determine the rates of complications within 30 days (including re-operation and re-admission), 90-day symptomatic venous thromboembolism and all-cause mortality. There were 301 701 operations performed between 2005 and 2010 – an annual incidence of 9.9 per 10 000 English population. Of these, 16 552 (6%) underwent ligament reconstruction and 106 793 (35%) underwent meniscal surgery. The 30-day re-admission rate was 0.64% (1662) and 30-day wound complication rate was 0.26% (677). The overall 30-day re-operation rate was 0.40% (1033) and the 90-day pulmonary embolism rate was 0.08% (230), of which six patients died. 90-day mortality was 0.02% (47). Age < 40 years, male gender and ligament reconstruction were significantly associated with an increased rate of 30-day re-admission and unplanned re-operation. In addition, a significant increase in 30-day admission rates were seen with Charlson comorbidity scores of 1 (p = 0.037) and ≥ 2 (p <  0.001) compared with scores of 0, and medium volume units compared with high volume units (p < 0.001).

Complications following arthroscopy of the knee are rare. It is a safe procedure, which in the majority of cases is performed as day case surgery. These data can be used for quality benchmarking, in terms of consent, consultant re-validation and individual unit performance.

Juvenile idiopathic arthritis (JIA) is a chronic disease of childhood; it causes joint damage which may require surgical intervention, often in the young adult. The aim of this study was to describe the long-term outcome and survival of hip replacement in a group of adult patients with JIA and to determine predictors of survival for the prosthesis. In this retrospective comparative study patients were identified from the database of a regional specialist adult JIA clinic. This documented a series of 47 hip replacements performed in 25 adult patients with JIA. Surgery was performed at a mean age of 27 years (11 to 47), with a mean follow-up of 19 years (2 to 36). The mean Western Ontario and McMaster Universities osteoarthritis index questionnaire (WOMAC) score at the last follow-up was 53 (19 to 96) and the mean Health Assessment Questionnaire score was 2.25 (0 to 3). The mean pain component of the WOMAC score (60 (20 to 100)) was significantly higher than the mean functional component score (46 (0 to 97)) (p = 0.02). Kaplan-Meier survival analysis revealed a survival probability of 46.6% (95% confidence interval 37.5 to 55.7) at 19 years, with a trend towards enhanced survival with the use of a cemented acetabular component and a cementless femoral component. This was not, however, statistically significant (acetabular component, p = 0.76, femoral component, p = 0.45). Cox’s proportional hazards regression analysis showed an implant survival rate of 54.9% at 19 years at the mean of covariates.

Survival of the prosthesis was significantly poorer (p = 0.001) in patients who had been taking long-term corticosteroids and significantly better (p = 0.02) in patients on methotrexate.

Interest in football continues to increase, with ever younger age groups participating at a competitive level. Football academies have sprung up under the umbrella of professional clubs in an attempt to nurture and develop such talent in a safe manner. However, increased participation predisposes the immature skeleton to injury. Over a five-year period we have prospectively collected data concerning all injuries presenting to the medical team at Newcastle United football academy. We identified 685 injuries in our cohort of 210 players with a mean age of 13.5 years (9 to 18). The majority of injuries (542;79%) were to the lower limb. A total of 20 surgical procedures were performed. Contact injuries accounted for 31% (210) of all injuries and non-contact for 69% (475).The peaks of injury occurred in early September and March. The 15- and 16-year-old age group appeared most at risk, independent of hours of participation. Strategies to minimise injury may be applicable in both the academy setting and the wider general community.

The role of modular tibial implants in total knee replacement is not fully defined. We performed a prospective randomised controlled clinical trial using radiostereophotogrammetric analysis to compare the performance of an all-polyethylene tibia with a metal-backed cruciate-retaining condylar design, PFC-∑ total knee replacement for up to 24 months. There were 51 patients who were randomised into two treatment groups. There were 10 subsequent withdrawals, leaving 21 all-polyethylene and 20 metal-backed tibial implants. No patient was lost to follow-up. There were no significant demographic differences between the groups. At two years one metal-backed implant showed migration > 1 mm, but no polyethylene implant reached this level. There was a significant increase in the SF-12 and Oxford knee scores after operation in both groups.

In an uncomplicated primary total knee replacement the all-polyethylene PFC-∑ tibial prosthesis showed no statistical difference in migration from that of the metal-backed counterpart. There was no difference in the clinical results as assessed by the SF-12, the Oxford knee score, alignment or range of movement at 24 months, although these assessment measures were not statistically powered in this study.

Statement of purpose: To evaluate survivorship and knee function in patients who have undergone Kinematic Condylar Total Knee Replacement at a minimum of 15 years.

Methods: We evaluated all patients undergoing primary cemented TKR with the Kinematic Condylar implant (Howmedica), between January 1981 and December 1988. All operations were performed by a single surgeon through a medial parapatellar approach, with sparing of the PCL, all cemented and no patellae resurfaced.

Operation notes were analysed to confirm the type of procedure, underlying diagnosis, and thickness of tibial insert. Information was derived from patient records and postal questionnaire to all surviving patients, which included: WOMAC, SF-36, satisfaction scale and history of revision surgery.

Results: We have identified a total of 804 consecutive cases, 185 of these were bilateral giving a total of 619 patients. Mean age at implantation was 66 (range 17 to 83), with female:male ratio of 3:1. The underlying diagnosis was Osteoarthritis in 49%, and Rheumatoid Arthritis in 51% of patients.

As at September 2003 there were 153 patients (25%) still alive, using revision as an endpoint survivorship was 59.3% at a mean time since implantation of 17 years 8 months. Pain and function portions of the WOMAC questionnaire revealed mean scores of 37 and 47 out of 100.

Conclusion: This cohort has been shown to have 92% implant survivorship at ten years. We have shown that the survivorship deteriorates significantly between 10 and 17 years. Functional and pain scores after 17 years for patients with surviving implants were poor.

Survival was significantly better in females, no effect from pre-operative diagnosis was seen. 73% of these patients had 6mm tibial inserts, we postulate that the deterioration in survival is related to accelerated poly-ethylene wear beyond 10 years.

Statement of purpose: To study the biology of tendon – bone integration in human hamstring tendon autograft at the femoral tunnel interface

Methods: A total of 70 patients undergoing revision anterior cruciate surgery for both traumatic and atraumatic injury were studied. All surgery was performed under the supervision of the senior author. At time of surgery tissue was taken from the residual graft and femoral tunnel. The demographics of the original surgery, mechanism of failure, patient characteristics were recorded. We have also recorded variables such as tunnel positioning, early rehabilitation, associated ligamentous laxity. Local ethical committee approval has been granted. The specimens were analysed for gross evidence of cell necrosis, macrophage and fibroblast ingrowth (H& E). Vascularity was quantified by multiple high powered field counting. The influence of makers of cell turnover and matrix degradation have been determined by cell staining for TIMP-1, -2 and –3 (Immunohistochemistry) and early correlations drawn between the histological findings and patient factors such as mechanism of reinjury. We have also examined the graft expression of receptors of IGF1, FGF, MMP-1, 7, 8, 11, and 13 as key markers of collagen remodelling.

Results: We have found novel expression of MMP-13 in collagen graft tissue. There is clear evidence in a subgroup of certain patients exhibiting aggressive vascular ingrowth in association with IGF and MMP-11 and −13 expression suggesting a possible regulatory process. Areas of poor cellularity appear to exhibit low levels of MMP-13 but moderate levels IGF-II suggesting an alternative cellular response to graft fixation at the femoral tunnel. There appear to be distinct subgroups of cellular response in patients with atraumatic failure.

Conclusion: This is the first study to the biology of ACL graft failure at the bone tendon interface in a human model. Previous work has been case reports or using a canine model. These have limited application to the clinical work. We have found clear evidence of a processs of graft – host bone integration through neovascularisation. There is evidence of the graft remodelling through local expression of collagen resorptive agents. This work is being extended to look at the role of exogenous factors in augmenting graft integration at the host site.

J Bone Joint Surg Am. 1993 Dec;75(12):1795–803.

Am J Sports Med. 2001 Nov–Dec;29(6):689–98.

Methods Mol Biol. 2001;151:389–97.

Statement of purpose: We studied anterior knee function in a cohort of patients with either osteoarthritis or rheumatoid disease who had undergone knee replacement in a single unit using a standard implant.

We identified a consecutive series of patients who had undergone knee replacement surgery for either osteoarthritis or rheumatoid disease between 1990 and 1995 under the care of a single surgeon using the same implant and surgical technique. There were ninety patients in each group. All were examined and underwent radiography of the anterior compartment. Data was collated for Hospital for Special Surgery (HSS) score, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score, a specific patellar score and a Visual Analog score (VAS).

Results: There were no discernible differences between the rheumatoid and osteoarthritis groups in all the measured scores, with good anterior knee function noted in both.

Conclusion: Based on our outcome studies in a matched group of patients no differences were found for anterior knee function between osteoarthritis or rheumatoid disease. We do not routinely resurface the patella and do not consider there to be any particular indication for such in the rheumatoid disease patient.

We carried out 60 revision procedures for failed porous coated anatomic total knee replacements in 54 patients, which were divided into two groups. The 14 knees in group I had a well-fixed femoral component at surgery which was retained, and in the 46 knees in group II both tibial and femoral components were loose and were revised using a variety of implants. Our review comprised clinical and radiological assessment.

A total of 13 knees required a second revision. Six (42%) in group I failed very early (mean 2.1 years) when compared with seven (15%) in group II (mean 6.8 years). Failure was due to wear of the polyethylene insert by the abraded, retained femoral component (crude odds ratio 4.07; 95% CI 1.07 to 15.5). We recommend a complete change of primary bearing surfaces at the time of revision of an uncemented total knee replacement in order to prevent early wear of polyethylene.

There is little data on the long-term outcome of rotating hinge total knee arthroplasty. We provide a clinical and radiographic assessment of survivorship of the Kinematic rotating hinge total knee arthroplasty (How-medica, Rutherford, NJ), in a series of 72 implants, performed by a single surgeon in one unit, between 1983 and 1997. Survival analysis using known all cause revision revealed a 92% five-year implant survival, but worst-case scenario was 31% at five years.

In a subset of 27 patients we used the Nottingham Health Profile (NHP) to assess prospectively the changes in health-related quality of life following rotating hinge arthroplasty. In this salvage arthroplasty setting we demonstrate a significant improvement in two modalities of the NHP (pain and physical mobility).

Introduction: Arthroscopic A.C.L. reconstruction using Semitendinosus (S.T.) and Gracilis (Gr.) tendons is a popular technique for the treatment of ACL deficient knees. It is common to find accessory tendinous bands (vinculae) arising from these two tendons when harvesting them. The implications are that extra care must be taken with the use of the tendon stripper if one is to avoid cutting the main tendon. Our clinical experience reveals that these connections are highly variable and, contrary to popular thinking, may be present beyond 10cm. proximally.

Aim: Our aim was to map these intertendinous connections and assess their variability using a cadaveric model. In particular we were interested to identify the presence of vinculae arising proximally beyond 10cm.

Procedure: We dissected the tendons of Gr. and S.T. of ten embalmed adult human cadaveric legs. Various vinculae from both tendons were identified and their origin and insertion mapped. All measurements were done using the tibial crest as a reference.

Results: We found that vinculae have a high variability. Bands were seen between tendons, connecting them to the popliteal fascia, sartorius, gastrognemis, pretibial and superficial fascia. Vinculae originated more than 10cm proximally from Semitendinosus and Gracilis in eight and two occasions respectively. There was a constant connection band between S.T. and the grastrocriernius fascia.

Conclusion: Our results confirm that vincular anatomy is more variable than previously reported. Surgeons should be aware of our new finding of vinculae commonly originating beyond 10cm. proximally. This work has prompted us to investigate the role of MRI for pre-operatively templating vinculae.

Purpose: To study the effect of retaining an abraded femoral component on the outcome of primary revision of uncemented total knee prosthesis.

Method: 66 revision procedures for failed uncemented porous coated anatomic (PCA) total knee replacement were performed in 60 patients. At review, four patients had died while two were lost to follow up, therefore 60 knees in 54 patients were included in this prospective study. The principal indications for primary revision were polyethylene wear and loosening of the tibial base plate. 14 patients had a well fixed femoral component and hence were retained while 46 patients had both the components revised. All patients were prospectively assessed prior to surgery, at three months, six months and yearly thereafter. Review comprised clinical and radiological assessment. The mean follow up was 8.4 yrs (7–12 yrs)

Summary of results: The mean pre-operative Hospital for Special Surgery knee score after the first revision improved at a follow up of 8.4yr (7–12yr) giving 39 (65%) excellent, 17 (28.4%) good and four (6.6%) poor results. 13 out of 60 knees needed a further revision. Six of these second revisions which had only the tibial component changed failed very early (mean of 2.1 yr) when compared to the rest (6.8yr), probably due to wear between the abraded retained femoral component and polyethylene insert. The estimated odds ratio (relative risk) of second revision in patients with retained femoral component compared to those with revision of both the components was 4.17 (95% C.I. 1.07 – 15.4).

Conclusion: We recommend exchange of all the components at the time of revision of PCA knee prostheses. Significance: To our knowledge, this is the only study involving such a large number of PCA revisions and looking into the effect of retaining the femoral component compared to changing both the components on the outcome of revision.

Aim: To prospectively determine the functional outcome of revision total knee replacement (TKR).

Method: We carried out a prospective outcome study recruiting 65 consecutive revision total knee replacements carried out by the senior author between 1992 and 1995. The indications for revision were aseptic loosening in 40 cases, instability in 7, infection in 4, and 16 cases for other causes. All patient was assessed preoperatively and at 3 and 12 months postop using the Nottingham Health Profile (NHP) to measure general health status. As part of this ongoing study, followup data is available for 24 patient at 5 years.

Results: There were 65 revisions in 60 patients, 5 being bilateral. There were 37 females and 23 males, with a mean age of 63 years (range 29 to 86 years). The preoperative scores showed that the patient had significant disability related to their failed TKR. Three months postop, there was a significant improvement in the NHP scores for pain and social isolation. At 12 months, the level of pain was again significantly improved over the 3 month score.

At 5 years, the pain score for the revision group deteriorated but remained better than the baseline level. This is in contrast to post primary TKR, where the improvement in pain score was maintained from 3 months onwards.

Conclusion: This study shows a significant improvement in the level of pain following revision knee arthroplasty. However, patients remain significantly disabled afterwards and do not show the very marked improvement in general health seen after primary TKR.

Introduction: The management of the acutely locked knee remains controversial. The incidence of ‘benign’ causes for an acutely locked knee that do not require surgical intervention is perhaps greater than is generally appreciated.

Aim: To study the features of the acutely locked knee, identifying which features are predictive of the cause of the locking.

Patients: Consecutive patients presenting with an acutely locked knee for Orthopaedic consultation were included in the study.

Methods: A prospective cross-sectional study was undertaken to observe the management of acutely locked knees.

Results: To date, forty patients presenting with acutely locked knees have been studied. Thirty-eight underwent examination and arthroscopy under general anaesthesia. 85% of patients were found to have distinct pathology causing a mechanical block to full extension. Eight percent were found to have only degenerative change and two patients unlocked without any surgical intervention. In those patients found to have a mechanical block to extension, consistent features of a definitive injury, joint line tenderness and the presence of an effusion were strongly predictive. We are currently evaluating an algorithm for the pre-operative prediction of remediable mechanical causes of locking.

Discussion: We suggest that patients presenting with acutely locked knees due to a non-mechanical cause can be identified consistently based upon the history and examination alone.

Aim: To determine the quality of life and radiological outcome of the rotating hinge total knee prosthesis as a salvage procedure for failed knee arthroplasty.

Methods: Forty-seven consecutive revision total knee arthroplasties, using the rotating hinge component, implanted between November 1983 and June 1997, were studied. The principal indications for surgery were pain with ligamentous laxity and gross bone loss. There were 43 patients, 11 males, 32 females, 19 left and 28 right, 21 with rheumatoid disease and 22 with osteoarthritis. The mean age at revision was 68 years, mean time from primary procedure to revision of 8 years and a mean number of previous knee procedures of 1.6 (range 1–5). The average time to final follow-up was 5 years. Quality of life was determined using the Nottingham Health Profile (NHP) combined with standard clinical and radiological assessment.

Results: Of the 47 revision procedures, full clinical follow-up information was available on 43 (91.5%), radiographic follow-up on 38 (80.9%). Complications occurred in 10 out of the 47 arthroplasties (21.3%) including 4 deep infections, 2 femoral fractures, 2 patients with clinically apparent aseptic loosening and 2 significant extensor mechanism problems. Survivorship analysis revealed a 5year cumulative implant survival of 89%. Significant improvements in quality of life (pain and physical mobility) were shown at 12 months post-operatively.

Discussion: This is a prospectively-studied series of salvage arthroplasty procedures. We regard quality of life as a key indicator of surgical success after knee arthroplasty. Rotating hinge arthroplasty offers objective and reproducible improvement in quality of life for failed knee arthroplasty with ligamentous instability.

Aim: To prospectively determine whether social deprivation has an effect on the level of disability at presentation and the outcome from total knee replacement (TKR).

Method: A prospective outcome study was carried out between 1992 and 1996, recruiting over 2500 total knee replacements. All patients were assessed preoperatively and at 3 and 12 months postop using the Knee Society (KS) scores for clinical evaluation and the Nottingham Health Profile (NHP) to measure general health status. The Townsend Score was used as the index of social deprivation and was calculated for each patient on the basis of their address.

Results: There was no significant difference between either the Knee Society or NHP scores at baseline and the Townsend Score. This indicated that social deprivation has no effect on the level of the knee arthritis immediately prior to joint replacement, both in terms of patient disability and health status.

There was also no significant difference between either the Knee Society or NHP scores postoperatively and the Townsend Score. This indicated that social deprivation has no effect on the outcome from knee replacement.

Conclusion: This study shows that social deprivation has no significant effect on the level of disability at presentation and the outcome from total knee replacement. This is contrary to previously published reports which have shown worse outcomes in more deprived patients.