Revision total knee arthroplasty (rTKA) is a technically challenging and costly procedure. It is well-documented that primary TKA (pTKA) have better survivorship than rTKA; however, we were unable to identify any studies explicitly investigating previous rTKA as a risk factor for failure following rTKA. The purpose of this study is to compare the outcomes following rTKA between patients undergoing index rTKA and those who had been previously revised. This retrospective, observational study reviewed patients who underwent unilateral, aseptic rTKA at an academic orthopaedic speciality hospital between June 2011 and April 2020 with > one-year of follow-up. Patients were dichotomized based on whether this was their first revision procedure or not. Patient demographics, surgical factors, postoperative outcomes, and re-revision rates were compared between the groups.Aims
Methods
OBJECTIVES. The use of a mobile bearing has been suggested to decrease the rate of patellar complications after total knee arthroplasty (TKA). However, to resurface or retain the native patella remains debated. Few long-term results have been documented. The present retrospective study was designed to evaluate the long-term (more than 10 years) results of mobile bearing
Introduction. Computed tomography (CT) based preoperative planning provides useful information for severe TKA and revision TKA cases, such as the amount of augmentation, length of stem extension and component alignment, to achieve correct alignment and joint line. In this study, we evaluated TKA alignment performed with CT preoperative planning. Materials and Methods. 7 primary
Outcomes for guided motion primary total knee arthroplasty (TKA) in obese patients are unknown. 1,684 consecutive patients underwent 2,059 primary
Aims. Simultaneous bilateral total knee arthroplasty (TKA) has been used due to its financial advantages, overall resource usage, and convenience for the patient. The training model where a trainee performs the first TKA, followed by the trainer surgeon performing the second TKA, is a unique model to our institution. This study aims to analyze the functional and clinical outcomes of bilateral simultaneous TKA when performed by a trainee or a supervising surgeon, and also to assess these outcomes based on which side was done by the trainee or by the surgeon. Methods. This was a retrospective cohort study of all simultaneous bilateral
Aims. Varus-valgus constrained (VVC) devices are typically used in revision settings, often with stems to mitigate the risk of aseptic loosening. However, in at least one system, the VVC insert is compatible with the primary posterior-stabilized (PS) femoral component, which may be an option in complex primary situations. We sought to determine the implant survivorship, radiological and clinical outcomes, and complications when this VVC insert was coupled with a PS femur without stems in complex primary total knee arthroplasties (TKAs). Methods. Through our institution’s total joint registry, we identified 113 primary
The Columbus® knee system was designed as a standard knee implant that allows high flexion without the need for additional bone resection. The aim of this retrospective study was to investigate the correlation between the maximum flexion achieved at five years and the slope of the tibial component. The hypothesis was that increased slope would give increased flexion. The study design was a retrospective cohort study at a single centre. The inclusion criterion was having had a navigated cemented Columbus primary TKA implanted between March 2005 and December 2006 using the image free OrthoPilot® navigation system (Aesculap, Tuttlingen, Germany) in our institution. Follow-up had been carried out at review clinics by an independent arthroplasty team. Patient-related data had been recorded either in case notes, the departmental proprietary database or as radiographic images. In addition to demographics, five-year follow-up range of motion (ROM) was collected. All available radiographs on the national Picture Archiving and Communication System (Eastman Kodak Company, 10.1_SP1, 2006), whether taken at our institution or at the patient's local hospital, were analysed by a trainee orthopaedic surgeon (NCS) who was independent of the patients' care. Component position according to the Knee Society TKA scoring system was determined from the five-year review lateral x-ray. The tibial slope was calculated as 90° minus the angle of the tibial component so giving a posterior slope as a positive number and an anterior slope as a negative number. The correlation between maximum flexion angle and tibial slope was calculated. Further to this a subgroup of only CR prostheses and patients with BMI <35 were analysed for a relationship. The tibial slope of the group of patients having 90° or less of flexion (poor flexion) was compared to those having 110° or more (good flexion) using a t-test, as was the flexion of the those with BMI <30 to those with BMI > 35. A total of 219 knees in 205 patients were identified. 123 had five-year radiograph and maximum flexion measurement available. Cohort demographics were mean age 68(8.6), mean BMI 32.0(5.9) and mean maximum flexion at five years of 101°(11°). The tibial slope angle showed variation around the mean of 2°(2.8°). There was no correlation between tibial slope and maximum flexion for either that whole cohort (r=-0.051, p=0.572, Figure 1b) or the subgroup of CR and BMI <35 patients (n=78, r = −0.089, p=0.438). The mean tibial slope of those patients having poor flexion was 2° (SD2.6°) and this was not significantly different to the mean for those with good flexion, 3° (SD3.1°) p=0.614. The mean flexion of those with BMI <30 was 100° (SD8.7°) and this was not significantly different to those with BMI >35, mean 101° (SD11.4°). This study did not find any correlation between the tibial slope and maximum flexion angle in 123
To assess the outcome and complication rate of rotating hinge knee prostheses in our unit. From our knee database we have identified 137 consecutive rotating hinged TKRs (implanted 2004–2010) for severe instability, arthrofibrosis and severe bone loss in either primary or revision arthroplasty. Prospective pre-operative scores and post-operative scores were obtained. 23 had died or were lost to follow-up. This left 114 cases with complete outcome and complication data.Aim
Method
Although total knee arthroplasty (TKA) has been a reliable procedure providing durable pain relief, polyethylene (PE) wear remains a major limitation of the long-term success of TKA. One potential method of lowering PE wear in TKA is to use oxidized zirconium (OxZr)-bearing surface. Although wear simulating testing of an OxZr counter surface of femoral component produced less PE wear and fewer particles than did cobalt-chrome (Co-Cr) counter surface of femoral component [1–4], this finding has not been demonstrated in vivo to our knowledge. We measured in vivo PE wear by isolating and analyzing PE wear particles in synovial fluid from wellfunctioning TKA [5]. The purpose of the current study was to determine the size, shape, and amount of PE wear particles isolated from synovial fluid of patients who underwent a bilateral simultaneous TKA prosthesis, but different materials of femoral components. We performed a bilateral simultaneous TKA in 100 patients (200 knees) who received an OxZr femoral component in one knee and a Co-Cr femoral component in the other. Mean age was 55.6 (44–60) years. Synovial fluid was obtained from 28 patients (56 knees) who had undergone a simultaneous bilateral TKA under completely sterile conditions at one or two years after the operation. Randomization to an OxZr or Co-Cr femoral component was accomplished with use of a sealed study number envelope, which was opened in the operating room before the skin incision had been made. After the opening the randomization envelope, the first knee received prosthesis indicated by the envelope (OxZr or Co-Cr component) and the contralateral (second TKA) knee received the other prosthesis (OxZr or Co-Cr component). All operations were performed by one surgeon using the same design of total knee prosthesis: Genesis II (Smith and Nephew, Memphis, Tennessee). Only the material of the femoral component differed between two groups. The preoperative diagnosis was osteoarthritis in all patients. Preoperative and post operative KS and HSS knee scores, KS functional scores and UCLA activity scores were evaluated. The amount of polyethylene wear particles in the aspirated synovial fluid sample was analyzed by thermogravimetic analysis (TGA) using a TGA instrument (TGA/SDTA 84le model, Mettler Toledo CO., Greifensee, Switzerland). The weight of the sample solution was measured before and after removing the organic content by heating the sample solution. The sample solution was casted onto petri dishes. The petri dish was covered and kept in a dry oven at 60°C for 2 days. While the sample solution was kept in a dry oven for 2 days, a small hole was made on the cover of the petri dish to allow water to evaporate slowly for 2 days. After this procedure, the cover of petri dish was removed and TGA sample was dried at 60°C for another 2 days. After the sample was completely dried out, the dried sample was measured using analytical balance. TGA was used to determine the weight change profiles of polyethylene subject to heating under a nitrogen atmosphere. The nitrogen flow rate was kept constant at 50mL per minute. TGA data were taken at heating rate as 5°C per minute in the temperature range of 20° to 1000°C. The weight loss data were recorded as a function of time and temperature using special software in computer. When the temperature reached to the point of decomposition of the sample, the sample started to lose weight. By calculating the weight of the sample around the temperature which led to start to decomposition, real amount of polyethylene in the sample was measured. The size and shape of PE particles were examined using scanning electron microscopy (JSH-6360A model, Jeol Co., Tokyo, Japan). The samples were coated using a platinum sputtering machine for 20 sec. ANOVA, nonparametric chi square test, nonpaired t-test and Mann-Whitney U-test were used for statistical analyses. Differences of P<
0.05 were considered statistically significant. Mean preoperative KS (27.5 vs 27.2 points) scores, HSS (51.1 vs 51.2 points) knee scores, KS functional scores (55.4 vs 55.4 points) and UCLA activity scores (2.8 vs 2.8 point) were not significantly different between two groups. Mean postoperative KS (93 vs 92 points), HSS knee scores (90 vs 89 points), KS functional scores (78 vs 78 points), and UCLA activity scores (7.8 vs 7.8) were not significantly different. Mean weight of the polyethylene particles was 0.0219 g (SD, 0.0058) in the Co-Cr femoral component groups and it was 0.0214 g (SD, 0.005) in the OxZr group. This difference was not significant (P=0.711139, paired t-test). The size of particles was not different between the two groups. Also, shape of particles was not different between the two groups. Under the condition and the duration of this study in this specific group of patients, TKA with OxZr or Co-CR femoral knee component had excellent clinical and radiographic outcomes with no osteolysis. While the wear simulator test in vitro demonstrated significant decrease in PE particles in the knees with an OxZr femoral component, our study in vivo revealed that total particle weight, size, and shape of PE wear particles were similar in the knees with an OxZr femoral component and in those with a Co-Cr femoral component.
Aims. Total knee arthroplasty (TKA) is a common and safe orthopaedic procedure. Zimmer Biomet's NexGen is the second most popular brand of implant used in the UK. The primary cause of revision after the first year is aseptic loosening. We present our experience of using this implant, with significant concerns around its performance with regards early aseptic loosening of the tibial component. Methods. A retrospective, single-surgeon review was carried out of all of the NexGen Legacy Posterior Stabilized (LPS)
Aims. The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources. Methods. Day-case
Aim. Antimicrobial resistance (AMR) aggravates an already difficult treatment of periprosthetic joint infections (PJI). The prevalence of drug-resistant pathogens varies across countries and increases over time. Regular monitoring of bacteriological analyses should be performed. Due to many factors influencing the AMR, the correct choice of antimicrobial management remains arguable. The primary purpose of this retrospective study was to identify and compare causative bacteria and to compare the incidence of antibiotic resistance between the septic revision total knee arthroplasty (TKA) and septic revision total hip arthroplasty (THA). Method. A review of all revision
Aims. While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) resulting from MA. Methods. A retrospective cohort study was undertaken of 700 primary MA
Aims. Nearly 99,000 total knee arthroplasties (TKAs) are performed in UK annually. Despite plenty of research, the satisfaction rate of this surgery is around 80%. One of the important intraoperative factors affecting the outcome is alignment. The relationship between joint obliquity and functional outcomes is not well understood. Therefore, a study is required to investigate and compare the effects of two types of alignment (mechanical and kinematic) on functional outcomes and range of motion. Methods. The aim of the study is to compare navigated kinematically aligned
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. Methods. Well-functioning primary
Aims. Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA. Methods. A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years’ consultant experience in the NHS and fulfilling any one of the following criteria: a ‘high volume’ knee arthroplasty practice (> 150
Aims. The use of high tibial osteotomy (HTO) to delay total knee arthroplasty (TKA) in young patients with osteoarthritis (OA) and constitutional deformity remains debated. The aim of this study was to compare the long-term outcomes of TKA after HTO compared to TKA without HTO, using the time from the index OA surgery as reference (HTO for the study group, TKA for the control group). Methods. This was a case-control study of consecutive patients receiving a posterior-stabilized TKA for OA between 1996 and 2010 with previous HTO. A total of 73
Aims. Up to one in five patients undergoing primary total hip (THA) and knee arthroplasty (TKA) require contralateral surgery. This is frequently performed as a staged procedure. This study aimed to determine if outcomes, as determined by the Oxford Hip Score (OHS) and Knee Score (OKS) differed following second-side surgery. Methods. Over a five-year period all patients who underwent staged bilateral primary THA or TKA utilizing the same type of implants were studied. Eligible patients had both preoperative and one year Oxford scores and had their second procedure completed within a mean (2 SDs) of the primary surgery. Patient demographics, radiographs, and OHS and OKS were analyzed. Results. A total of 236 patients met the inclusion criteria, of which 122 were THAs and 114