Cementless fixation of Oxford Unicompartmental Knee Replacements (UKRs) is an alternative to cemented fixation, however, it is unknown whether cementless fixation is as good long-term. This study aimed to compare primary and long-term fixation of cemented and cementless Oxford UKRs using radiostereometric analysis (RSA). Twenty-nine patients were randomised to receive cemented or cementless Oxford UKRs and followed for ten years. Differences in primary fixation and long-term fixation of the tibial components (inferred from 0/3/6-month and 6-month/1-year/2-year/5-year/10-year migration, respectively) were analysed using RSA and radiolucencies were assessed on radiographs. Migration rates were determined by linear regression and clinical outcomes measured using the Oxford Knee Score (OKS).Abstract
Introduction
Methodology
Re-revision knee replacement (RR-KR) is complex surgery, with a significant impact on individual patients and health resource use. The aim of this study was to investigate early patient-relevant outcomes following RR-KR. 206 patients (250 knees) undergoing RR-KR were recruited from a major revision centre between 2015–2018. Patient-relevant outcomes assessed were: implant survivorship, complications (90-days), joint function and quality of life (final follow-up). Risk factors for further revision surgery at 1 year were investigated using multiple logistic regression.Abstract
Introduction
Methodology:
Since 2012 we have routinely used the cementless Oxford medial unicompartmental knee arthroplasty (mUKA), with microplasty instrumentation, in patients with anteromedial osteoarthritis (AMOA) meeting modern indications. We report the 10-year survival of 1000 mUKA with minimum 4-year follow-up. National Joint Registry (NJR) surgeon reports were interrogated for each senior author to identify the first 1,000 mUKAs performed for osteoarthritis. A minimum of 4 years follow-up was required. There was no loss to follow-up. The NJR status of each knee was established. For each mUKA revision the indication and mechanism of failure was determined using local patient records. The 10-year implant survival was calculated using life-table analysis.Abstract
Background
Methods
Aims
Materials and Methods
Endoprosthetic replacement (EPR) is an available option for the management of massive bone loss around failed knee implants. The aim of this study was to determine the results of knee EPRs performed for non-tumour indications. Since 2007, 85 EPRs were performed for in a single tertiary centre by seven surgeons. Mean age at surgery was 73.5 years (range:35–95) with infection as the most common indication (49%), followed by aseptic loosening (18%), complex primary replacement (16%), fracture (15%) and mechanical failure (2%). Mean follow up was 4 years (range:1–9). Functional outcome was determined using the Oxford Knee Score (OKS). At follow-up, 21 patients were deceased and 2 lost to follow-up. Complication rate was 19%. Of the 7 infected cases, 6 were treated with DAIR (debridement, antibiotics, and implant retention) and one underwent above knee amputation. Four of the patients undergoing DAIR were cleared of infection and 2 are on long-term antibiotics. Accounting for implant revision, loss to follow-up and those on long-term antibiotics as failures, 5-year survival was 89% with an average OKS of 25 (SD=10). This mid-term study shows that distal femur EPR is a valuable option for the increasing burden of complex revision knee surgery
Since 2011, the knee service at the Nuffield Orthopaedic Centre has been offering a neutralising medial opening wedge high tibial osteotomy (HTO) to a group of patients presenting with early medial osteoarthritis of the knee, varus alignment and symptoms for more than 2 years. During development of this practice an association was observed between this phenotype of osteoarthritis and the presence of CAM deformity at the hip. A retrospective cohort study. All patients who underwent HTO since 2011 were identified (n=30). Comparator groups were used in order to establish whether meaningful observations were being made: Control group: The spouses of a high-risk osteoarthritis cohort recruited for a different study at our unit (n=20) Pre-arthroplasty group: Patients who have undergone uni-compartmental arthroplasty (UKA) for antero-medial osteoarthritis (n=20)All patients had standing bilateral full-length radiographs available for analysis using in house developed Matlab-based software for hip measurements and MediCAD for lower limb alignment measurements.Background
Methods
The burden of peri-prosthetic joint infection (PJI) following hip and knee surgery is increasing. Endoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants. To determine clinical outcome of EPRs for treatment of PJI around the hip and knee joint.Introduction
Aims
Restrictions placed on the working hours of doctors have led to increasing time-pressures on surgical training. Consequently, there has been growing interest in developing new techniques to teach and assess technical skills. The primary aim of this study was to determine whether a novel set of visual parameters assessing visuospatial ability, fine motor dexterity and gaze control could objectively distinguish between varying levels of arthroscopic experience. The secondary aim was to evaluate the correlations between these new parameters and previously established technical skill assessment methods. 27 subjects were divided into a “novice” group (n=7), “trainee” group (n=15) and expert group (n=5) based on previous arthroscopic experience. All subjects performed a diagnostic knee arthroscopy task on a simulator. Their performance was assessed using new simple visual parameters that included “prevalence of instrument loss,” “triangulation time” and “prevalence of look downs”. In addition, performance was also evaluated using previously validated technical skill assessment methods (a global rating scale and motion analysis).Introduction
Methods
Motion analysis is a validated method of assessing technical dexterity within surgical skills centers. A more accessible and cost-effective method of skills assessment is to use a global rating scale (GRS). We aimed to perform a validation experiment to compare an arthroscopic GRS against motion analysis for monitoring orthopaedic trainees learning simulated arthroscopic meniscal repairs. An arthroscopic meniscal repair task on a knee simulator was set up in a bioskills laboratory. Nineteen orthopaedic trainees with no experience of meniscal repair were recruited and their performance assessed whilst undertaking a standardized meniscal repair on 12 occasions. An arthroscopic GRS, assessing parameters such as “depth perception,” “bimanual dexterity,” “instrument handling,” and “final product analysis” was used to evaluate technical skill. Performance was assessed blindly by watching video recordings of the arthroscopic tasks. Dexterity analysis was performed using a motion analysis tracking system which measured “time taken,” “total path length of the subject's hands,” and “number of hand movements”.Introduction
Methods
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
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
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
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
Rheumatology and Musculoskeletal Sciences, NIHR Biomedical Research Unit, University of Oxford and the Nuffield Orthopaedic Hospital, Oxford The aim of this study was to use motion analysis to objectively study the learning curve of surgical trainees performing arthroscopic meniscal repair on a training model in a skills laboratory. With improving technology and an appreciation of its likely chondroprotective effects, meniscal repair surgery is becoming more common. It remains a difficult procedure and is not routinely learnt during surgical training.Purpose
Background
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
A feasibility study of the use of an MRI based patient specific knee arthroplasty system within the NHS. Introducing new technologies within a public funded health system can be challenging. We assess the use and potential benefit of customised jigs for knee arthroplasty. Outcomes assessed were safety and accuracy of implantation. Eight knee replacements using custom jigs were compared to 11 conventionally instrumented replacements matched to surgeon and operative day. Parameters measured include tourniquet time; drain output; hospital stay; adjusted change in haemoglobin; complications; and component position on post-operative long-leg alignment films None of the parameters observed demonstrated a statistically significant difference from the conventional arthroplasty group. No complications were seen in either group. No significant differences were seen in alignment. Our early experiences show that this technology appears safe and allows accurate implantation of the prosthesis. There was a trend for decreased stay and blood loss. The health economic benefits of navigational arthroplasty have been demonstrated in other studies and come from the lack of instrumentation of the intramedullary canal. MRI based patient specific instrumentation is considered technically easier and more convenient than intra-operative navigation. A larger study is planned to assess the health economic implications of adopting this new technology.
100% of medial compartments showed full thickness anteromedial loss with preservation of the posteromedial cartilage. When present, the meniscus was extruded in 96% of cases. 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.
We believe this technique provides good oncological and functional results and recommend this treatment option is considered in young active patients required distal fibula excisions for sarcoma.
This study evaluated the long term outcome of isolated posterior cruciate ligament (PCL) reconstruction. Thirty patients underwent surgery with hamstring tendon autograft after failing conservative management. At 10 years after surgery patients were assessed with radiographs, full IKDC examination and KT1000 instrumented testing. The mean IKDC subjective knee score was 87 out of a possible 100. Regular participation in moderate to strenuous activities improved from 26% preoperatively to 88% of patients. At 10 years endoscopic reconstruction of the PCL with hamstring tendon autograft is effective in reducing knee symptoms. Patients can expect to continue participating in moderate to strenuous activties over the long term. Osteoarthritis is observed in some patients with 18% showing some loss of joint space which compares favorably with non-operatively managed PCL injuries. This is a successful procedure for symptomatic patients with PCL laxity who have failed conservative management.
In 2004, our centre has changed from the “STAR” to the “Mobility” Total Ankle Replacement device and a study was undertaken in order to ascertain if there was a learning curve to useage of this new device and perform a comparison in terms of survival, function, additional procedures and complications. The indications were 55% osteoarthritis, 30% Rheumatoid and 8% JIA with the remainder being haemophiliac, haemochromatosis and ankylosing spondylitis. One third of TARs in this unit are combined with additional procedures such as subtalar fusion. Only isolated TARs were considered in this study and the tourniquet time, wound problems, length of stay and known complications for the last 20 STAR TARs was compared to the first 20 Mobility TARs. 68 Mobility TARs have been implanted since Oct 2004 and survival data was collected for this entire cohort and compared to a similar number of STARs.
The survival curve of the mobility and STAR shows no loss of the Mobility due to revision at up to 3 years. Clinical outcome scores will be presented.
The early results for this new prosthesis show no cause for concern and surveillance is ongoing.
