Aims. We compared the risks of re-revision and mortality between two-stage revision surgery and single-stage revision surgery among patients with infected primary knee arthroplasty. Methods. Patients with a periprosthetic joint infection (PJI) of their primary knee arthroplasty, initially revised with a single-stage or a two-stage procedure in England and Wales between 2003 and 2014, were identified from the National Joint Registry. We used Poisson regression with restricted cubic splines to compute hazard ratios (HR) at different postoperative periods. The total number of revisions and re-revisions undergone by patients was compared between the two strategies. Results. A total of 489 primary knee arthroplasties were revised with single-stage procedure (1,390 person-years) and 2,377 with two-stage procedure (8,349 person-years). The adjusted incidence rates of all-cause re-revision and for infection were comparable between these strategies (HR overall five years, 1.15 (95% confidence interval (CI) 0.87 to 1.52), p = 0.308; HR overall five years, 0.99 (95% CI 0.70 to 1.39), p = 0.949, respectively). Patients initially managed with single-stage revision received fewer revision procedures overall than after two-stage revision (1.2 vs 2.2, p < 0.001). Mortality was lower for single-stage revision between six and 18 months postoperative (HR at six months, 0.51 (95% CI 0.25 to 1.00), p = 0.049 HR at 18 months, 0.33 (95% CI 0.12 to 0.99), p = 0.048) and comparable at other timepoints. Conclusion. The risk of re-revision was similar between single- and two-stage revision for infected primary knee arthroplasty. Single-stage group required fewer revisions overall, with lower or comparable mortality at specific postoperative periods. The single-stage revision is a safe and effective strategy to treat infected knee arthroplasties. There is potential for increased use to reduce the burden of knee PJI for patients, and for the healthcare system. Cite this article: Bone Joint Res 2022;11(10):690–699

Abstract. Introduction. There is a longstanding presumed association between obesity, complications, and revision surgery in primary knee arthroplasty. This has more recently been called into question, particularly in centres where a high volume of arthroplasty is performed. We investigated the correlation between Body Mass Index (BMI), mortality, and revision surgery. Method. This was a cohort study of at least 10 years following primary knee arthroplasty from a single high volume arthroplasty unit. Mortality and revision rates were collected from all patients who underwent primary knee arthroplasty between 2009 and 2010. Kaplan Meier analysis was performed. Results. There were 1161 female and 948 male patients with a mean age of 69 (21 to 97). All cause survivorship excluding mortality was 97.2% up to 13yrs with a minimum of 10 years. The revision rate in this series was 2.8% with no significant difference in revision rates after 10 year between patients with BMI above and below 40 (p=0.438). There was no significant difference in 10-year mortality between patients above and below a BMI of 40 (p=0.238). Conclusion. This study shows no significant difference in the long term survival of total knee replacement between patients with normal and high BMI. Careful consideration should be given before rationing surgery based on BMI alone

There is a longstanding presumed association between obesity, complications, and revision surgery in primary knee arthroplasty. This has more recently been called into question, particularly in centres where a high volume of arthroplasty is performed. We investigated the correlation between Body Mass Index (BMI), mortality, and revision surgery. This was a cohort study of at least 10 years following primary knee arthroplasty from a single high volume arthroplasty unit. Mortality and revision rates were collected from all patients who underwent primary knee arthroplasty between 2009 and 2010. Kaplan Meier analysis was performed. There were 1161 female and 948 male patients with a mean age of 69 (21 to 97). All cause survivorship excluding mortality was 97.2% up to 13yrs with a minimum of 10 years. The revision rate in this series was 2.8% with no significant difference in revision rates after 10 year between patients with BMI above and below 40 (p=0.438). There was no significant difference in 10–year mortality between patients above and below a BMI of 40 (p=0.238). This study shows no significant difference in the long term survival of total knee replacement between patients with normal and high BMI. Careful consideration should be given before rationing surgery based on BMI alone

Aims. The aim of this study was to report the meaningful values of the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) and EuroQol visual analogue scale (EQ-VAS) in patients undergoing primary knee arthroplasty (KA). Methods. This is a retrospective study of patients undergoing primary KA for osteoarthritis in a university teaching hospital (Royal Infirmary of Edinburgh) (1 January 2013 to 31 December 2019). Pre- and postoperative (one-year) data were prospectively collected for 3,181 patients (median age 69.9 years (interquartile range (IQR) 64.2 to 76.1); females, n = 1,745 (54.9%); median BMI 30.1 kg/m. 2. (IQR 26.6 to 34.2)). The reliability of the EQ-5D-3L was measured using Cronbach’s alpha. Responsiveness was determined by calculating the anchor-based minimal clinically important difference (MCID), the minimal important change (MIC) (cohort and individual), the patient-acceptable symptom state (PASS) predictive of satisfaction, and the minimal detectable change at 90% confidence intervals (MDC-90). Results. The EQ-5D-3L demonstrated good internal consistency with an overall Cronbach alpha of 0.75 (preoperative) and 0.88 (postoperative), respectively. The MCID for the Index score was 0.085 (95% confidence interval (CI) 0.042 to 0.127) and EQ-VAS was 6.41 (95% CI 3.497 to 9.323). The MIC. COHORT. was 0.289 for the EQ-5D and 5.27 for the EQ-VAS. However, the MIC. INDIVIDUAL. for both the EQ-5D-3L Index (0.105) and EQ-VAS (-1) demonstrated poor-to-acceptable reliability. The MDC-90 was 0.023 for the EQ-5D-3L Index and 1.0 for the EQ-VAS. The PASS for the postoperative EQ-5D-3L Index and EQ-VAS scores predictive of patient satisfaction were 0.708 and 77.0, respectively. Conclusion. The meaningful values of the EQ-5D-3L Index and EQ-VAS scores can be used to measure clinically relevant changes in health-related quality of life in patients undergoing primary KA. Cite this article: Bone Joint Res 2022;11(9):619–628

Aims. This study investigates whether primary knee arthroplasty (KA) restores health-related quality of life (HRQoL) to levels expected in the general population. Methods. This retrospective case-control study compared HRQoL data from two sources: patients undergoing primary KA in a university-teaching hospital (2013 to 2019), and the Health Survey for England (HSE; 2010 to 2012). Patient-level data from the HSE were used to represent the general population. Propensity score matching was used to balance covariates and facilitate group comparisons. A propensity score was estimated using logistic regression based upon the covariates sex, age, and BMI. Two matched cohorts with 3,029 patients each were obtained for the adjusted analyses (median age 70.3 (interquartile range (IQR) 64 to 77); number of female patients 3,233 (53.4%); median BMI 29.7 kg/m. 2. (IQR 26.5 to 33.7)). HRQoL was measured using the three-level version of the EuroQol five-dimension questionnaire (EQ-5D-3L), and summarized using the Index and EuroQol visual analogue scale (EQ-VAS) scores. Results. Patients awaiting KA had significantly lower EQ-5D-3L Index scores than the general population (median 0.620 (IQR 0.16 to 0.69) vs median 0.796 (IQR 0.69 to 1.00); p < 0.001). By one year postoperatively, the median EQ-5D-3L Index score improved significantly in the KA cohort (mean change 0.32 (SD 0.33); p < 0.001), and demonstrated no clinically relevant differences when compared to the general population (median 0.796 (IQR 0.69 to 1.00) vs median 0.796 (IQR 0.69 to 1.00)). Compared to the general population cohort, the postoperative EQ-VAS was significantly higher in the KA cohort (p < 0.001). Subgroup comparisons demonstrated that older age groups had statistically better EQ-VAS scores than matched peers in the general population. Conclusion. Patients awaiting KA for osteoarthritis had significantly poorer HRQoL than the general population. However, within one year of surgery, primary KA restored HRQoL to levels expected for the patient’s age-, BMI-, and sex-matched peers. Cite this article: Bone Joint J 2023;105-B(4):365–372

Aims. The aim of this study was to assess factors associated with the estimated lifetime risk of revision surgery after primary knee arthroplasty (KA). Methods. All patients from the Scottish Arthroplasty Project dataset undergoing primary KA during the period 1 January 1998 to 31 December 2019 were included. The cumulative incidence function for revision and death was calculated up to 20 years. Adjusted analyses used cause-specific Cox regression modelling to determine the influence of patient factors. The lifetime risk was calculated as a percentage for patients aged between 45 and 99 years using multiple-decrement life table methodology. Results. The estimated lifetime risk of revision ranged between 32.7% (95% confidence interval (CI) 22.6 to 47.3) for patients aged 45 to 49 years and 0.6% (95% CI 0.1 to 4.5) for patients aged over 90 years. At 20 years, the overall cumulative incidence of revision (6.8% (95% CI 6.6 to 7.0)) was significantly less than that of death (66.3% (95% CI 65.4 to 67.1)). Adjusted analyses demonstrated converse effect of increasing age on risk of revision (hazard ratio (HR) 0.5 (95% CI 0.5 to 0.6)) and death (HR 3.6 (95% CI 3.4 to 3.7)). Male sex was associated with increased risks of revision (HR 1.1 (95% CI 1.1 to 1.2); p < 0.001) and death (HR 1.4 (95% CI 1.3 to 1.4); p < 0.001). Compared to patients undergoing primary KA for osteoarthritis, patients with inflammatory arthropathy had a higher risk of death (HR 1.7 (95% CI 1.7 to 1.8); p < 0.001), but were less likely to be revised (HR 0.9 (95% CI 0.7 to 1.0); p < 0.001). Patients with a greater number of comorbidities (HR 1.4 (95% CI 1.3 to 1.4)) and greater levels of socioeconomic deprivation (HR 1.4 (95% CI 1.4 to 1.5)) were at increased risk of death, but neither increased the risk of revision. Conclusion. The estimated lifetime risk of revision KA varied depending on patient sex, age, and underlying diagnosis. Patients aged between 45 and 49 years had a one in three risk of undergoing revision surgery within their lifetime, which decreased with age to one in 159 in those aged 90 years or more. Cite this article: Bone Joint J 2022;104-B(12):1313–1322

The June 2024 Knee Roundup. 360. looks at: The estimated lifetime risk of revision after primary knee arthroplasty influenced by age, sex, and indication; Should high-risk patients seek out care from high-volume surgeons?; Stability and fracture rates in medial unicondylar knee arthroplasties; Rethinking antibiotic prophylaxis for dental procedures post-arthroplasty; Evaluating DAIR: a viable alternative for acute periprosthetic joint infection; The characteristics and predictors of mortality in periprosthetic fractures around the knee; Patient health-related quality of life deteriorates significantly while waiting six to 12 months for total hip or knee arthroplasty; The importance of looking for diversity in knee implants

Introduction and Objectives: Currently it has become popular to use cement impregnated with antibiotics in revisions of septic total knee replacements. However, the use of cement with antibiotics in primary knee arthroplasties continues to be a cause of controversy. However, contrary to American opinion, in some European studies it has been seen that the use of cement with antibiotics decreases the infection rate in primary knee arthroplasties. Materials and Methods: We hereby present a comparative study of 642 patients that underwent primary total knee replacement (TKR) (Legacy-Zimmer) between 2003 and 200. We divided the patients into 2 groups. One group of 296 patients underwent primary TKR using cement without antibiotic. A second group of 346 patients underwent primary TKR using gentamycin-loaded cement. Mean follow-up was 1 year. Our aim was to find differences in postoperative infection rates during the first year of follow-up. Results: We found no differences in demographic variables, operation time, ischemia time, rate of transfusions, days of hospitalization or medical complications. We saw 10 infections (3.3% infection rate) in group 1. We saw 3 infections (0.09 % infection rate) in group 2. We carried out a comparative statistical analysis and it was significant. Discussion and Conclusions: Cement impregnated with gentamycin is effective in the prevention of deep infection in the short and medium term in primary total knee replacement

Abstract. INTRODUCTION. This study investigates whether primary knee arthroplasty (KA) restores health-related quality of life (HRQoL) to levels expected in the general population. METHODOLOGY. This retrospective case-control study utilises two sources: patients undergoing primary KA from a University Teaching hospital; and individual-level data from the Health Survey for England which was used to represent the General Population. Propensity score matching was used to balance covariates (sex, age and body mass index (BMI)) and facilitate group comparisons. Two matched cohorts with 3029 patients each were obtained for the adjusted analyses (median age 70.3 interquartile range (IQR) 64–77; Female sex 3233 (53.4%); median BMI 29.7 IQR 26.5-33.7). HRQoL was measured using the three-level version of the EuroQol 5-Dimensions’ (EQ-5D-3L) Index and EQ-VAS scores. RESULTS. Patients awaiting KA had significantly lower EQ-5D-3L Index scores than the General Population (median 0.620 (IQR 0.16-0.69) vs median 0.796 (IQR 0.69-1.00), p<0.001). By one-year post-operation, the median EQ-5D-3L Index score improved significantly in the KA cohort (mean change 0.32 (Standard deviation 0.33), p<0.001), and demonstrated no significant differences when compared to the General Population (0.796 (IQR 0.69-1.00) vs 0.796 (0.69-1.00), p=1.0). Older age-groups had statistically better Index scores than matched peers in the General Population. Compared to the General Population cohort, the post-operative EQ-VAS was significantly higher in the KA cohort (p<0.001). CONCLUSION. Patients awaiting KA for osteoarthritis have significantly poorer HRQoL than the General Population. However, within one year of surgery, primary KA restored HRQoL to levels expected for patient's age, BMI and sex-matched peers

This study aims to determine the lifetime risk of revision surgery after primary knee arthroplasty (KA). The Scottish Arthroplasty Project dataset was utilised to identify all patients undergoing primary KA during the period 1998–2019. The cumulative incidence function for revision and death was calculated and adjusted analyses utilised cause-specific Cox regression modelling to determine the influence of patient-factors. The lifetime risk was calculated for patients aged between 45–99 years using multiple decrement lifetable methodology. The lifetime risk of revision ranged between 32.7% (95% Confidence Interval (CI) 22.62–47.31) for patients aged 45–49 years and 0.63% (95%CI 0.1–4.5) for patients aged over 90 years. Adjusted analyses demonstrated the converse effect of age on revision (Hazard Ratio (HR) 0.5, 95%CI 0.5–0.6) and death (HR 3.5, 95%CI 3.4–3.7). Male sex was associated with increased risks of revision (HR 1.1, 95%CI 1.1–1.2) and death (HR 1.4, 95%CI 1.3–1.4). Patients with inflammatory arthropathy had a higher risk of death (HR 1.7, 95%CI 1.7–1.8), but were less likely to be revised (HR 0.85, 95%CI 0.74–0.98) than those treated for osteoarthritis. Patients with greater number of comorbidities and greater levels of socio-economic deprivation were at increased risk of death, but neither increased the risk of revision. The lifetime risk of revision knee arthroplasty varies depending on patient sex, age at surgery and underlying diagnosis. Patients aged between 45 and 49 years have a one in three probability of revision surgery within their lifetime. Conversely, patients aged 90 years or over were very unlikely to experience revision

Introduction. A smartphone-based care platform allows a customizable educational and exercise interface with patients, allowing many to recover after surgery without the need for formal physical therapy (PT). Furthermore, advances in wearable technology to monitor physical activity (PA) provides patients and physicians quantifiable metrics of the patient's recovery. The purpose of this study is to determine the feasibility of a smartphone-based exercise educational platform after primary knee arthroplasty as well as identifying factors that may predict the need for formal physical therapy. Methods. This study is part of a multi-institution, prospective study of patients after primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA) enrolled in a smartphone with smartwatch-based episode of care platform that recorded multimodal PA (steps, kcal, stairs). Postoperatively, all patients initially followed the smartphone-based exercise program. At the surgeon's discretion, patients were prescribed therapy if needed. The outcome of this study was the need for PT outside the app-based exercise program as well as time to return to preoperative step count. Variables assessed were preoperative weekly step counts (steps/day), weekly postoperative activity level (weekly step count compared to preoperative level), compliance with the exercise program (>75% completion) and patient demographic data including gender, age, BMI and narcotic use. One hundred eighty-eight patients were included in analysis: 45 PKA (24%) and 143 TKA (76%). Step count data was available on 135 patients and physical therapy data on 174. Results. Overall educational compliance was 91% and exercise compliance 34%. By 4-weeks postop, 45.6% of patients reached or exceeded their preoperative step count, including 60% of PKA and 41% of TKA (p=0.05). There was no significant difference in reaching step count based on gender (p=0.7), BMI <40kg/m2 (p=0.9) or age <65-years old (p=0.67). Sixty-three percent of patients that were compliant with the exercise program reached the step count compared to 40% of patients that weren't complaint (p=0.01). One hundred thirty-three patients (76.4%) completed the app-based exercise program without the need for PT, which included 81.4% of PKA patients and 75% of TKA patients (p=0.38). Weekly compliance with the exercise program (>75%) was significantly associated with not needing PT (p<0.001). Other factors that were significantly associated with the need for PT were a high physical activity level in postoperative week 1 (p<0.001) and a low physical activity level in postoperative week 2 (p=0.002). Conclusion. A high percentage of patients after primary knee arthroplasty were able to successfully complete the smartphone-based exercise program without the need for PT. Compliance with the exercise program was an important predictor of success. Postoperative activity level may also indicate the need for therapy as patients who were very active in the first postoperative week and then saw a decline in activity in the second week were more likely to be prescribed PT. With this platform, surgeons can monitor a patient's exercise compliance and postoperative activity level allowing many to recover at home, while being able to identify those within the first few weeks who may need structured physical therapy. For figures, tables, or references, please contact authors directly

Introduction. The purpose of this study was to examine the effects of baseline mental health on functional outcomes after primary knee arthroplasty by reviewing the data collected in a multi-centre prospective observational cohort study. We hypothesised that those patients with lower baseline mental health status would demonstrate significantly worse outcomes vs their counterparts with higher mental status following primary total knee arthroplasty. Methods. Data from a multi-centre prospective cohort study of PS (posterior stabilising implant) and CR (cruciate retaining implant) primary knee arthroplasty were compared to determine the relationship between baseline mental health status and functional outcomes post-surgery. Subjects were followed from the time of the index surgery to monitor outcomes and complications. Validated quality of life instruments, including SF-36, WOMAC, Knee Society Score, and an activity scale were used. Changes from baseline to 1 year on the SF-36 and WOMAC were evaluated. Regression analysis was completed to assess changes in WOMAC based on baseline SF-36 scores. All analyses were adjusted for age, BMI, gender, and implant type. Results. Baseline data was available for 436 subjects in the primary PS study and 493 subjects in the primary CR study. Patients improved significantly on all SF-36 and WOMAC components between baseline and 12 months post-surgery. Correlation and regression analysis between WOMAC and SF-36 showed that Global Health (GH), Mental Health (MH), Role-Emotional (RE), and Mental Component Score (MCS) subscales on the SF-36 were significantly associated with positive post-operative changes in WOMAC scores. Conclusion. This study examined the effects of baseline mental health on functional outcomes after primary knee arthroplasty and found that baseline mental health was a significant predictor of functional outcomes twelve months after surgery. This relationship between mental health and outcomes needs to be examined carefully to help surgeons better prepare their patients for surgery

Background. The purpose of this study is to evaluate the early perioperative outcomes after primary knee arthroplasty with the use of a smartphone-based exercise and educational platform compared to a standard of care control group. Methods. A multicenter prospective randomized control trial was conducted evaluating the use of the mymobility smartphone-based care platform for primary total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA). Patients in the control group (224 patients) received the respective institution's standard of care typically with formal physical therapy. Those randomized to mymobility treatment group (192 patients) were provided an Apple Watch and mymobility smartphone application. The treatment group was not initially prescribed physical therapy, but could if their surgeon determined it necessary. Early outcomes assessed included 90-day knee range of motion, KOOS Jr scores, 30-day single leg stance (SLS) time, Time up and Go (TUG) time and need for manipulation under anesthesia (MUA). There was no significant difference in age, BMI or gender between groups. Results. The 90-day knee flexion was not significantly different between controls (118.3±11.8) and mymobility (118.8 ±12) (p=0.7), nor was knee extension (1.6 ±3.5 vs. 1 ±3.1, p=0.16). KOOS Jr scores were not significantly different between control group (74 ±13.1) and mymobility group (71 ±13.3) (p=0.06). 30-day SLS was 22.3 ± 19.5 sec in controls and 24 ± 20.8 sec in mymobility (p=0.2). 30-day TUG times were 16 ± 44.3 sec in control and 15 ± 40.6 sec in mymobility (p=0.84). MUAs were performed in 4.02% of patients in the control group and 2.8% in the mymobility group (p=0.4%). Conclusion. The use of the mymobility care platform demonstrated similar early outcomes to traditional care models, while providing communication and insights into patient engagement with the care plan. There was no significant difference in 90-day range of motion or need for MUA

Infection after total knee replacement, which is a serious and expensive complication, often represent a diagnostic and therapeutic problem. The current incidence of infection after the primary procedure is 1 to 3%, depending on the published series. A correct and timely diagnosis, classification between early and delayed infection, and which microorganisms are involved, are crucial steps in defining prevention and treatment strategies. Determination of the annual and three years incidence of infection after primary total knee replacement; evaluation of the microorganisms involved and its resistance patterns; assessment of treatment – surgical approach and selection of antibiotics. Collection of clinical and laboratorial data of all patients who underwent primary total knee arthroplasty between 2011 and 2013 in our hospital; definition of periprosthesic infection cases following the Musculoskeletal Infection Society (MSIS) criteria. During the study period, 526 primary knee replacements were performed in 521 patients; with 41 patients having bilateral replacements. The mean follow-up period was 30 months; 5 patients had no follow up and 1 died in the post operatory. We reported 9 prosthetic infections, of which 2 did not reached the MSIS criteria, but were also considered based on high clinical suspicion. The majority of the cases (6) were delayed infections. The calculated 3 year incidence of infection after primary knee replacement was 1,6%, with annual rates of 3,0% (2011), 1,7% (2012) and 0,9% (2013). The microorganisms isolated were as follows: Staphylococcus aureus and coagulase-negative staphylococci, resistant to penicillin; Streptococcus agalactiae and one isolate of Serratia marcescens, both showing multiple antibiotic resistances. Only one case was treated with surgical debridement and conservation of prosthesis, in the other 8 cases a two-stage implant revision procedure was performed. The antibiotics selected were vancomycin, fluoroquinolones and association of gentamicin and clindamycin. Our local infection rates are in line with the published series from reference surgical centers. The annual incidence is decreasing, probably because the majority of our infection cases are delayed (recent years, shorter follow up period) and our preventive measures are improving. The microorganisms identified are also in agreement with published data, and our antibiotic resistance pattern is a valuable information to consider in a first empirical approach. Treatment options suitable to each case, and antibiotic protocols need to be improved in our local practice. Preventive measures in delayed infections are still under debate, and represent another future challenge

Purpose: The purpose of this study was to examine the effects of baseline mental health on functional outcomes after primary knee arthroplasty by reviewing the data collected in a multi-center prospective observational cohort study. We hypothesized that those patients with lower baseline mental health status would demonstrate significantly worse outcomes vs. their counterparts with higher mental status following primary total knee arthroplasty. Method: Data from a multi-center prospective cohort study of PS (posterior stabilizing implant) and CR (cruciate retaining implant) primary knee arthroplasty were compared to determine the relationship between baseline mental health status and functional outcomes post-surgery. Subjects were followed from the time of the index surgery to monitor outcomes and complications. Validated quality of life instruments, including SF-36, WOMAC, Knee Society Score, and an activity scale were used. The rates of improvement from 0 to 12 months were analyzed for this study. Results: Baseline data was available for 436 subjects in the primary PS study and 493 subjects in the primary CR study. Patients improved significantly on all SF-36 and WOMAC components between baseline and 12 months post-surgery. Correlation and regression analysis between WOMAC and SF-36 showed that Global Health (GH), Mental Health (MH), and Mental Component Score (MCS) subscales on the SF-36 were significantly associated with positive post-operative changes in WOMAC scores. Conclusion: This study examined the effects of baseline mental health on functional outcomes after primary knee arthroplasty and found that baseline mental health was a significant predictor of functional outcomes twelve months after surgery. This relationship between mental health and outcomes needs to be examined carefully to help surgeons better prepare their patients for surgery

The Trent Arthroplasty Audit Group (TAAG) has been prospectively collecting data on primary knee arthroplasty since 1990 and revision procedures since 1992. To date details of 27 000 primary and 1300 revision knee arthroplasties, from both teaching and district general hospitals in the Trent region, have been contributed. This provides us with a unique opportunity to look at the outcome of total knee arthroplasty across an English region, at 10 or more years of follow-up. A questionnaire was designed, with assistance from the department of epidemiology and public health, including both generic (EuroQol) and knee specific questions. Patients who underwent primary knee arthroplasty from 1990–92 were included in the study (4420 patients). Surviving patients (65%) were traced using the NHSIA patient tracing service and the questionnaire was administered by post with a response rate was 55%. The mean length of follow-up was 11 years 7 months and the mean age at the time of follow-up was 78 years. The vast majority (86%) of patients were satisfied with their joint replacement. Although 52 % took prescribed analgesia for pain in their knee, 22% still complained of pain often or all the time. 18% felt their knee totally or greatly interfered with their usual activities. 14% of patients reported re-operation on their knee, of which 11% were revision procedures. This suggests that a significant number of patients experience pain and/or disability at 10 or more years following knee replacement. Since most GPs have a high threshold for re-referral in this group of patients, it is likely that the degree of morbidity has previously been underestimated in the orthopaedic community

We discuss the role of primary knee arthroplasty in supracondylar and intercondylar fractures of the femur in elderly patients with reference to 13 cases. This method of treatment is shown to be effective and to have good results. It is recommended for all type C and some type A supracondylar fractures in old people

Aims: To report the outcome of secondary patellar resurfacing in patients with chronic anterior knee pain following primary total knee replacement. Methods: A total of twenty patients identified over a 10-year period from 623 patients managed without patellar replacement during primary knee arthroplasty were included and evaluated pre and postoperatively using the American Knee Society (AKS) score, as well as by radiological analysis. Results: The mean follow up was 36.1 months (range 12–104 months). The mean knee score improved from 46.7 to 62.2 points while the mean functional score increased from 44.7 to 52.2 points. Only 44.5% of the patients reported some improvement whereas the remaining reported no change or deterioration. Postoperative radiographic alignment of the primary knee arthroplasty did not influence outcome of secondary patellar resurfacing. Complications were noted in 6 of the 20 patients including patella fracture, patella instability and loss of a range of movement. Conclusions: Anterior knee pain following knee arthroplasty remains a difficult condition to manage and secondary resurfacing of the patella is clearly not to be advocated in all patients since it may well increase patient dissatisfaction and hasten revision

Introduction. Although we know that smoking damages health, we do not know impact of smoking on a patient's outcome following primary knee arthroplasty (KA). In the UK, clinical commissioning groups (CCGs) have the authority (& funds) to commission healthcare services for their communities. Over the past decade, an increasing number of CCGs are using smoking as a contraindication for patients with end-stage symptomatic knee arthritis being referred to a specialist for due consideration of KA without any clear evidence of the associated risks & benefits. The overall objective of this study is to compare clinical outcomes after knee arthroplasty surgery in smokers, ex-smokers & non-smokers. Methods. We obtained data from the UK Clinical Research Practice Datalink (CPRD) that contains information on over 11 million patients (7% of the UK population) registered at over 600 general practices. CPRD data was linked to Hospital Episode Statistics, hospital admissions & Patient Reported Outcome Measures (PROMs) data. We collected data on all KAs (n=64,071) performed over a 21-year period (1995 to 2016). Outcomes assessed included: local & systemic complications (at 6-months post-surgery): infections (wound, respiratory, urinary), heart attack, stroke & transient ischaemic attack, venous thromboembolism, hospital readmissions & GP visits (1-year), analgesic use (1-year), surgical revision (up to 20-years), mortality (90-days and 1-year), & 6-month change from pre-operative scores in Oxford Knee Score (OKS). Regression modelling is used to describe the association of smoking on outcomes, adjusting for confounding factors. Results. Smoking was associated with an increased risk of lower respiratory tract infections (LRTI) (4.2% smokers vs. 2.7% non-smokers) (Odds Ratio (OR) 0.76, p-value 0.017). LRTI were similar in ex-smokers & smokers at 3.9%. There was no association with any of the other 6-month complications. Pain medication use over 1-year post surgery was higher in smokers compared to non-smokers: gabapentinoids 7.4% vs. 5.2% (OR 0.74, p< 0.001), opioids 45.9% vs. 35.3% (OR 0.79, p< 0.001), NSAIDs 51.6% vs. 46.1% (OR 0.91, p = 0.044). Mortality was higher in smokers at 1-year compared to non-smokers (hazard ratio (HR) 0.53, p<0.001) & ex-smokers (HR 0.65, p = 0.037), but there was no difference observed at 90-days. There was no association of smoking on revision surgery over 20-years follow up. Smoking was associated with worse postoperative OKS being 3.1 points higher in non-smokers (p<0.001) & 3.0 points higher in ex-smokers (p<0.001). The overall change in OKS before & after surgery was 13.9 points in smokers versus 16.3 points in non-smokers (p<0.001) & 15.7 points in ex-smokers (p<0.001). Over the year following surgery, smokers were more likely to visit their GP, but there was no association with hospital readmission rates. Conclusion. This is the largest study with linked primary care & secondary care data highlighting impact of a preventable patient factor on outcome of a routinely performed planned intervention. Smokers achieved clinical meaningful improvements in patient reported pain & function (OKS) following KA, although their attained post-operative OKS was lower than in non-smokers & ex-smokers. Levels of pain medication use were notably higher in both smokers & ex-smokers. As smokers achieved good clinical outcomes following KA surgery, smoking should not be a barrier to referral for or consideration of KA. However, the study does highlight particular risks a patient is taking if he/she continues to smoke when being considered for elective knee arthroplasty. This study will help the family physicians as well as patients to make an informed decision on whether to go ahead with a planned intervention whilst patient continues to be an active smoker or not. Key Words: Knee Arthroplasty, Smoking, Patient Reported Outcomes, Epidemiology, Complications

The stemmed tibial implant has enabled the salvage of challenging situations of bone loss in primary knee arthroplasty. This ease of use has unfortunately led to the adoption of stemmed implants in situations where this may not be warranted. In general uncontained defects of less than 5 mm may be dealt with using cement fill techniques. Defect of less than 10mm require bone grafting techniques and those above 10 mm require stems and wedges. In the third category however long term results suggest that good results are only attainable in 65% of cases whether grafts or wedges are used. The use of intramedullary guides in this setting is re-addressed to allow the accurate placement of cuts enabling the use of pegged (or non-stemmed) implants. In addition with the advent of navigation this may be a special situation where non-stemmed implants may be selected over stemmed implants

Introduction. The precise indications for tibial component metal backing and modularity remain controversial in routine primary total knee arthroplasty. This is particularly true in elderly patients where the perceived benefits of metal backing such as load redistribution and the reduction of polyethylene strain may be clinically less relevant. The cost implications for choosing a metal-backed design over an all-polyethylene design may exceed USD500 per primary knee arthroplasty case. Methods. A prospective randomised clinical trial was carried out at the QEII Health Sciences Centre, Halifax, Nova Scotia, to compare modular metal-backed versus an all-polyethylene tibial component. Outcome measures included clinical range of motion, radiographs, survivorship, Knee Society Clinical Rating System, WOMAC and SF-12. Results. 116 patients requesting primary knee arthroplasty were recruited and randomised between the Smith & Nephew Genesis I non-modular (57) and modular (59) tibial designs between September 1995 and August 1997. At 10 years clinical follow-up, 4 implant revisions or intention-to-revise decisions were recorded in the metal-tray/modular group of which 2 were for aseptic tibial component loosening. 2 implant revisions in the all-polyethylene non-modular group were recorded, neither of which were for tibial component loosening. At 5, 7 and 10 year review; the KSCRS, WOMAC and SF12 scores were similar in both groups. As most patients randomised were over seventy years of age, this impacted significantly on the numbers available for longer term review and data was analysed by comparing pre- and post-operative scores for individual patients. Conclusion. There was no difference in performance between the all-polyethylene tibial component and the metal-backed tibial component. The case for using the all-polyethylene tibia in elderly patients is justified on both clinical efficacy and cost-containment grounds

Introduction. The Rapid Recovery Program (RRP) is a holistic perioperative accelerated discharge process that aims to improve efficiency and quality of care, improve patient education, standardise protocols and pathways and encourage early mobilisation & discharge. Aims. To compare length of stay (LOS) of primary knee arthroplasty patients before and after implementation of the RRP. Method. A retrospective cohort study of all patients admitted for knee arthroplasty was performed between 1. st. May 2007 and 28. th. February 2009. Data were obtained from hospital computer records. LOS of 2 groups compared: Pre-RRP implementation (Pre-RRP) and post-RRP implementation (post-RRP) and analysed using Welch's t- and chi square tests with significant at the p<0.05 level. (Definitions: Day of operation = ‘day 0’, first post-operative day = ‘day 1’, discharge = to the patient's own home). Results. 315 patients identified: 147 Pre-RRP (mean age 72 years; range 48-90) and 168 post-RRP (mean age 71 years; range 38-98). Mean LOS was reduced from 8.5 days (range 2-30) Pre-RRP to 5.9 days (range 2-38) post-RRP (p<0.01). Median LOS was reduced from 6 days (Pre-RRP) to 4 days (post-RRP) (p<0.01). Following RRP implementation, more patients were discharged on day 3 (Pre-RRP 9% vs Post RRP 30%; p<0.001) and less patients stayed more than 5 days (Pre-RRP 60% vs Post RRP 34%; p<0.001). Conclusion. The Rapid Recovery Programme significantly reduced LOS for knee arthroplasty patients, by a mean of 2.6 days. Significantly more patients were discharged by day 3 and significantly less stayed longer than 5 days. As well as cost savings, the patient experience was enhanced and the multidisciplinary team moral increased through centralised team work. Further evaluation of patient outcomes such as complication rates and patient satisfaction must be evaluated

Aims: To establish whether pre-existing anxiety and depression negatively impacts symptomatic and functional outcome of knee arthroplasty. Methodology: A prospective study. Ethical approval was obtained prior to the study. Psychological status was assessed using the Hospital Anxiety and Depression Scale; a validated self-assessment tool for detecting anxiety and depression. The Oxford and the American Knee society scores were used to assess the knee status. All scores were documented pre-operatively and at six weeks post-operatively. Results were submitted for independent statistical analysis. Results: 105 consecutive primary knee replacements were included in the study. 39% (41 patients) had abnormal pre-operative anxiety states. This percentage dropped to 28.2% (29 patients) post-operatively (P=0.034). 25.7% (27 patients) had abnormal pre-operative depression states which improved to 15.5% (16 patients) post-operatively (P=0.011). There were high degrees of correlation between abnormal anxiety and depression states both pre-operatively (P< 0.001) and post-operatively (P< 0.001). Patients with abnormal anxiety pre-operatively had worse knee scores both pre-operatively (P=0.17) and post-operatively (P=0.009) than those who did not. Patients with abnormal depression pre-operatively had worse pre-operative Oxford scores (P=0.036), and worse Oxford (p=0.006) and AKSS knee scores post-operatively (0.043). Conclusions: Abnormal anxiety and depression states are common in patients with knee arthritis presenting for knee arthroplasty. These conditions can improve post-operatively. Patients with abnormal pre-operative anxiety and depression do less well following knee arthroplasty than those who do not. Pre-operative psychological assessment is easy to perform and does act as a predictor of early outcome. Further research is needed to assess whether treating these psychological conditions prior to knee arthroplasty improves the outcome or not

Aims

The aim of this study was to perform a systematic review and bias evaluation of the current literature to create an overview of risk factors for re-revision following revision total knee arthroplasty (rTKA).

Aims

This study aimed to describe the use of revision knee arthroplasty in Australia and examine changes in lifetime risk over a decade.

Antibiotic-impregnated cement is frequently used for fixation of total knee prostheses as a measure to prevent postoperative infection. In recent years, more cementless knee prostheses have been implanted especially for younger patients. In 1997 to June 2004, 35044 primary total knee arthroplasties for primary or secondary osteoarthritis were performed in Finland and registered in nationwide arthroplasty register. The patients aged 70 years (range 21–96) on average, and 71.7% were women. During the median follow-up of 39 months (range 0–104), 978 (2.8%) knees were revised. There were 188 (0.58%), 21 (1.09%) and 10 (1.18%) reoperations due to infection after cemented, hybrid and cementless arthroplasties, respectively (p=0.003). In hybrid arthroplasties with cemented tibial component, the septic reoperation rate did not significantly differ from cemented arthroplasties. Instead, the higher number of infections after hybrid arthroplasty was related to use of cementless tibial components (5.3% vs. 0.9%, p< 0.008). In Cox regression model adjusted for age, gender and diagnosis, the hazard ratio for septic reoperation after knee replacement with cementless tibial component was 2.4 (95% CI 1.4–4.1) compared to the cemented alternative. The fixation method did not affect the rate of septic reoperations occurring after the first postoperative year. Cementless fixation of tibial component in primary total knee arthroplasty may associate with an increased risk of early septic reoperation. Until this finding is confirmed in other materials, cementless fixation in primary knee arthroplasty should be used cautiously in patients with increased risk for infection

Aims: To investigate whether normal statistical ßuctuation in the incidence of early complications of primary Knee Arthroplasty (TKA) follows the laws of statistical probability and can thus be amenable to analysis by standard Statistical Quality Control (SQC) methods. The þnal objective is to apply such techniques to distinguish random ßuctuation from real (undetected by traditional p value statistical methods) increase in the incidence of early complications in primary joint Arthroplasty. Methods: We employed statistical quality control charts (X-bar, p, c, u and np) to analyse postoperative complications and length of stay in 1,196 consecutive primary TKAs performed over a 20-quarter time period (October 1995 to September 2000). For all analyses (Minitab 12.1 software) the standard practice of employing ± 3 standard deviation upper and lower control limits and generally accepted criteria for determining the presence or absence of statistical control were used. Results: Deep infection, major thromboembolic incident, total number of complications per case and total number of complicated cases appeared to be in stable statistical control and followed the laws of statistical ßuctuation throughout the entire study period. However, patella mal-tracking, persistent knee stiffness, postoperative length of stay and total number of postoperative complications showed an (undetected by conventional postoperative audit methods) lack of control at various time periods with subsequent return to the statistically-controlled range. Conclusions: SQC methods may be employed in the audit of postoperative events in TKA and can be a valuable tool in continuous assessment of the statistical variability of postoperative complications, with the aim of reducing the variability and improving clinical outcome Arthritic knee imaging

Patients undergoing primary knee arthroplasty at our unit routinely have two units of red cell concentrate cross-matched preoperatively. We assessed whether postoperative blood salvage and auto-transfusion reduced the need for allogenic blood transfusion as compared with standard suction drainage. Haemoglobin and haematocrit preoperatively and postoperatively were recorded. The amount of drainage and re-transfusion was noted as well as the amount of blood saved, used and wasted. 182 patients were audited. Patients were placed in one of two groups: Group A receiving auto-transfusion of blood salvaged postoperatively (128 patients); and Group B where suction wound drainage without salvage was utilized (54 patients). Pre- and postoperative haemoglobin and haematocrit estimations were similar in both groups. Total drainage averaged 1061mI (range 175–2230 ml) for group A and 760mI (range 100–2280 ml) for group B. Auto-transfusion volumes averaged 814ml (range 0–1700m1) in group A. Allogenic blood transfusion was required in 23% of patients in group A in contrast to 50% in group B. This resulted in an average wastage of 1.6 units in group A as opposed to 1.1 units in group B. Postoperative auto-transfusion of salvaged blood in patients undergoing primary total knee arthroplasty reduces the need for allogenic blood transfusion requirements. It would also serve to reduce the wastage in units of whole blood allowing such patients to be routinely “grouped and retained” rather than “crossmatched”

This study aimed to analyze the effect of two different techniques of cement application: cement on bone surface (CoB) versus cement on bone surface and implant surface (CoBaI) on the short-term effect of radiolucent lines (RLL) in primary fully cemented total knee arthroplasties (TKA) with patella resurfacing.

379 fully cemented TKAs (318 patients) were included in this monocentric study. Preoperative and postoperative at week 4 and 12 month after surgery all patients had a clinical and radiological examination and were administered the Oxford Knee Score (OKS). Cement was applied in two different ways among the two study groups: cement on bone surface (CoB group) or cement on bone surface and implant surface (CoBaI group). The evaluation of the presence of RLL or osteolysis was done as previously described using the updated Knee Society Radiographic Evaluation System.

The mean OKS and range of motion improved significantly in both groups at the 4-week and 12-month follow-up, with no significant difference between the groups (CoB vs. CoBaI). RLL were present in 4.7% in the whole study population and were significantly higher in the CoBaI group (10.5%) at the 4-week follow-up. At the 12-month follow-up RLL were seen in 29.8% of the TKAs in the CoBaI group, whereas the incidence was lower in the CoB group (24.0% (n.s.)). There were two revisions in each group. None of these due to aseptic loosening.

Our study indicated that the application of bone cement on bone surface only might be more beneficial than onto the bone surface and onto the implant surface as well in respect to the short-term presence of RLL in fully cemented primary TKA.

The long-term results will be of interest, especially in respect to aseptic loosening and might guide future directions of bone cement applications in TKA.

Introduction: The postoperative rehabilitation after a primary knee arthroplasty may be infiuenced by a variety of factors. Nevertheless, only a few studies evaluated the effect of various factors on patients’ short-term outcome. This prospective study was conducted to evaluate the effect of different factors on patients’ function six weeks after the surgery. Patients and methods. We prospectively recruited 107 patients with osteoarthritis who underwent an uncomplicated total knee arthroplasty, using the same prosthesis and operative technique. Following variables were collected before and after the surgery: age, BMI, visual analogue pain score at rest and during activity, preoperative range of knee motion, involvement of other joints, comorbidities (Katz index), self assessed health status, admission and discharge hemoglobin levels, amount of blood transfusions and intensity of postoperative physiotherapy. In order to quantify patients’ level of functioning, we used a timed up and go test (TUG) and the Oxford knee score that were collected before and after the surgery. To eliminate the infiuence of postoperative weakness on rehabilitation, hand grip measurements were performed as well. A multivariate regression analysis was performed to examine the infiuence of different peri-operative variables on the outcome measures. Adjusted R2 was measured to estimate the explanatory power of infiuence of these variables. Results: There was no significant difference between preoperative and postoperative hand grip force measurements, indicating that the general strength of the patients did not deteriorate. A postoperative TUG was worse with higher preoperative TUG and higher rest pain score (adjusted R2=0.53). The amount of improvement in TUG was better only with lower rest pain score (adjusted R2=0.06). A postoperative Oxford hip score was better only with lower rest pain score (adjusted R2=0.30). The amount of improvement in the Oxford score was not infiuenced by any of the variables (adjusted R2=0.01). Only significant infiuences (p< 0.05) are mentioned. Discussion: Most of preoperative and postoperative measured variables, including age, BMI, comorbidities, hemoglobin concentration and amount of physiotherapy had no significant effect on patient’s functional status after uncomplicated knee arthroplasty. Only the pain at rest had infiuence on the functional result. These results suggest that patient personality has a most significant effect on knee arthroplasty results, either through pain perception or otherwise

Introduction

The purpose of this study was to characterize the recovery of physical activity following knee arthroplasty by means of step counts and flight counts (flights of stairs) measured using a smartphone-based care platform.

Periprosthetic joint infections (PJIs) are uncommon but are devastating complications of total knee replacement (TKR). We analysed the risk factors of revision for PJI following primary TKR and their association with PJI at different post-operative periods. Primary TKRs and subsequent revision surgeries performed for PJI from 2003–2014 were identified from the National Joint Registry (NJR). Multilevel piece-wise exponential non-proportional hazards models were used to estimate the effect of the investigated factors at different post-operative periods. Patient, perioperative and healthcare system characteristics were investigated and data from the Hospital Episode Statistics for England were linked to obtain information on specific comorbidities. The index TKRs consisted of 679,010 primaries with 3,659 subsequently revised for PJI, 7% within 3 months, 6% between 3–6months, 17% between 6–12months, 27% between 1–2years and 43% ≥2 years from the index procedure. Risk factors for revision for PJI included male sex, high BMI, high ASA grade and young age. Patients with chronic pulmonary disease, diabetes and liver disease had higher risk of revision for PJI, as had patients who had a primary TKR for an indication of trauma or inflammatory arthropathy. Surgical procedure, fixation method, constraint and bearing type influenced the risk of revision for PJI. Their effects were period-specific. No or small associations were found with the operating surgeon grade, surgical volume and hospital surgical volume. These findings from the world's largest joint replacement registry show a more complex picture than the meta-analyses published to date with specific time-dependent effects for the identified risk factors.

Background

Performing total knee replacement needs both bony & soft tissue consideration. Late John Insall advocating spacer blocks with concept of balanced & equal flexion – extension Gap. Although we usually excise both ACL & PCL, still it is possible to retain more soft tissue. Both PCL retaining & sacrificing Require intact collaterals for stability. Superficial MCL & LCL should be preserved, if possible. After PCL removal the following advantages could obtain: More correction of fixed varus or valgus deformity, More surgical exposure. but there are no proved disadvantages like; increasing in stress & loosening of bone-cement-prosthesis interface, specific clinical difference in ROM, forward lean during stepping up, proprioception inferiority. In other hand over tight PCL cause excessive rollback of tibia & knee hinges open, preventing flexion (booking), and Severe posteromedial poly wear in poor balance PCL might be happened. Mid range laxity when Post. Capsule is tight, even with correct tensioning in full extension & 90 degree flexion, may occur (and secondary collateral ligaments imbalance throughout ROM). There is a major effect of capsular contracture in coronal mal alignment with flexion contracture. Full MCL releases not only correct fixed varus but also open the medial space in flexion. MCL & post. Capsule has combined valgus resistant effect in extension. PCL release increase flexion gap more, May be necessary to release something that affect extension gap as compensated balancing (Post.medial capsule). Any flexion contracture need to posterior capsulotomy & post. Condyle osteophyte removal before femoral recut. So it is possible to perform posteromedial capsulotomy prior to superficial MCL release.

Aim

Patients reporting penicillin allergy do often receive clindamycin as systemic antibiotic prophylaxis. The effect of clindamycin has however not been compared to antibiotics with proven effect in joint arthroplasty surgery. The aim of the study was to reveal if there were differences in the rate of revision due to infection after total knee arthroplasty (TKA) depending on which antibiotic was used as systemic prophylaxis.

There has not been any published work quantifying the volume cement used/needed for knee arthroplasty. The number of mixes of cement used is at the discretion of the surgeon, based on their own experience/training.

The objective of this study was to quantify the volume of cement used for knee arthroplasty in our institution, and to observe variations between surgeons and implant size. The study then aimed to calculate the theoretical volumes required and observe the volume of cement actually implanted before commenting on cost implications of cement usage.

Prospective data for 85 consecutive knee arthroplasties performed by 9 consultants was examined. A single mix in this institution refers to 40g of Palacos R+G. Significant variation between surgeons was seen, with a range of one to three mixes being used. Several surgeons used one mix exclusively, independent of implant size, whilst others exclusively used two mixes. The departmental average was 1.4 mixes per knee. The total surface area of our largest implants (Size 8 Triathlon Femoral and Tibial components) was measured-108cm² and compared to the volume of a single mix of cement −49 cm³. Even using the largest component size, a single mix will provide 4.5mm of uniform cement coverage. The volume of cement actually implanted during 10 knee arthroplasties was examined by weighing the residual cement. The average volume of cement implanted was 18cm³ per knee.

In 2009 1085 knee replacements were performed in this institution. If all surgeons in the department used a single mix of cement this could potentially save £16,357.46 per year. (Presuming average usage was 1.4 mixes per knee, 434 ‘extra’ mixes were used, costing £37.69 each) We conclude that a single mix of cement will cover the area required for all Triathlon implants and that less than half a mix (on average) is actually implanted.

We report a ten-year rate of survival of 96% for the cemented Freeman-Samuelson knee arthroplasty in patients from the Swedish Knee Registry and the Royal London Hospital with revision for aseptic loosening as the criterion for failure.

Patient function is poorly characterised following revision TKA. Modern semi-constrained implants are suggested to offer high levels of function, however, data is lacking to justify this claim.

52 consecutive aseptic revision TKA procedures performed at a single centre were prospectively evaluated; all were revision of a primary implant to a Triathlon total stabiliser prosthesis. Patients were assessed pre-operatively and at 6, 26, 52 and 104 weeks post-op. Outcome assessments were the Oxford Knee Score (OKS), range of motion, pain rating scale and timed functional assessment battery. Analysis was by repeated measures ANOVA with post-hoc Tukey HSD 95% simultaneous confidence intervals as pairwise comparison. Secondary analysis compared the results of this revision cohort to previously reported primary TKA data, performed by the same surgeons, with identical outcome assessments at equivalent time points.

Mean age was 73.23 (SD 10.41) years, 57% were male. Mean time since index surgery was 9.03 (SD 5.6) years. 3 patients were lost to follow-up. All outcome parameters improved significantly over time (p <0.001). Post-hoc analysis demonstrated that all outcomes changed between pre-op, 6 week and 26 weeks post-op assessments.

No difference was seen between primary and revision cohorts in OKS (p = 0.2) or pain scores (p=0.19). Range of motion and functional performance was different between groups over the 2 year period (p=0.03), however this was due to differing pre-operative scores, post-hoc analysis showed no difference between groups at any post-operative time point.

Patients undergoing aseptic revision TKA with semi-constrained implants made substantial improvements in OKS, pain scores, knee flexion, and timed functional performance, with the outcomes achieved comparable to those of primary TKA. High levels of function can be achieved following revision knee arthroplasty, which may be important considering the changing need for, and demographics of, revision surgery.

We devised a four-part clinical risk classification system for patients undergoing primary total knee arthroplasty (PTKR) to facilitate risk estimation. We retrospectively reviewed a series of consecutive PTKRs performed by the senior author. A classification system was devised to take account of principal risk factors in PTKR (Table 1). The patients were grouped accordingly, and the following were compared:

Length of stay

Multiple regression analysis was performed. This revealed:

Similar complication rates in the NCP and CPI groups.

Conclusion: This classification correlates well with complication rates from surgery, and has a role in stratifying patients for preoperative planning and risk counselling. It is reproducible and can be used for larger patient groups via the National Joint Registry. Our findings also have implications for payment by results and fixed tariffs for PTKR.

Aims

To devise a simple clinical risk classification system for patients undergoing primary total knee arthroplasty (PTKR) to facilitate risk and cost estimation, and aid pre-operative planning.

The Oxford Knee Score (OKS) is a valid and reliable self-administered patient questionnaire that enables assessment of the outcome following total knee replacement (TKR). There is as yet no literature on the behavioral trends of the OKS over time. Our aim is to present a retrospective audit of the OKS for patients who have undergone TKR during the past ten years.

We retrospectively analysed 3276 OKS of patients who had a primary TKR and had been registered as part of a multi-surgeon, outcome-monitoring program at St. Helier hospital. The OKS was gathered pre-operatively and post-operatively by means of postal questionnaires at annual intervals. Patients were grouped as per their age at operation into four groups: 60, 61-70, 71- 80 and >80. A cross-sectional analysis of OKS at different time points was performed.

The numbers of OKS available for analysis were 504 pre-operatively, 589 at one-year, 512 at two-year and gradually decreasing numbers with 87 knees ten-year post-operatively. There was as expected a significant decrease (improvement) of the OKS between pre-operative and one-year post-operative period and then reached a plateau. Beyond eight years, there is a gradual rise in the score (deterioration). The younger patients (60) showed a significant increase in their average OKS between one and five-years post-operatively. However beyond five years, they followed the trend of their older counterparts. When the twelve questions in the OKS were analysed, certain components revealed greater improvement (e.g. description of knee pain and limping) than others (e.g. night pain).

The OKS is seen to plateau a year after TKR. According to the OKS the outcome of the TKR is not as good in the younger age group as compared to the older age group. Further investigation is required to ascertain the cause of this observed difference.

Out of a total of 623 patients who, over a ten-year period, underwent primary total knee replacement (TKR) without patellar resurfacing, 20 underwent secondary resurfacing for chronic anterior knee pain.

They were evaluated pre- and postoperatively using the clinical and radiological American Knee Society score. The mean follow-up was 36.1 months (12 to 104). The mean knee score improved from 46.7 to 62.2 points and the mean functional score from 44.7 to 52.2 points. Only 44.4% of the patients, however, reported some improvement; the remainder reported no change or deterioration. The radiographic alignment of the TKR did not influence the outcome of secondary resurfacing of the patella. Complications were noted in six of the 20 patients including fracture and instability of the patella and loss of movement.

Anterior knee pain after TKR remains difficult to manage. Secondary resurfacing of the patella is not advocated in all patients since it may increase patient dissatisfaction and hasten revision.

Restoration of the mechanical axis is thought to be a critical factor in determining the Outcome of knee replacement surgery. There is strong theoretical evidence that reproduction of this axis improves mechanical loading and hence longevity of the implant. Clinical studies are small in number.

Per-operative use of intra-and-extra-medullary alignment jigs help to determine the distal femoral and proximal tibial cuts. Studies have shown large margins of error using the standard jigs provided with most total knee replacement systems. On this basis computer assisted guidance systems are being introduced such as Orthopilot and BrainLab. These systems allow more accurate placement of the bony cuts and hence improve overall lower limb alignment.

No study has shown conclusively that accurately reproducing the mechanical axis of the lower limb improves survivorship of the implant. Prior to investing in these systems we felt it would be prudent to investigate how critical reproduction of the mechanical axis was in the primary total knee replacement.

We assessed 100 primary kinematic total knee replacements performed in 1990. All case notes were reviewed looking for basic demographics, pathology and clinical outcome.

All cases had a long leg film weight-bearing alignment film taken post-operatively. These were digitised and then analysed using Design CAD 97 software and from this the mechanical axis calculated.

Using these data the patients were divided into two groups. The first were within 3 degrees varus/valgus of the mechanical axis. The second were outside this range. These two groups were then correlated to clinical outcome.

Conclusions: Our results suggest that accurate reproduction of the lower limb alignment and the mechanical axis improves clinical outcome and survivorship of the implant using revision as an endpoint. Our data would support the introduction and use of intra operative computer aided guidance systems.

Restoration of the mechanical axis is thought to be a critical factor in determining the outcome of knee replacement surgery. There is strong theoretical evidence that reproduction of this axis improves mechanical loading and hence longevity of the implant. Per operative use alignment jigs help to determine the bony cuts. Studies have shown large margins of error using the standard jigs. On this basis computer navigation systems are being introduced. No study has shown conclusively that accurately reproducing the mechanical axis of the lower limb improves survivorship of the implant. Prior to investing in these systems we felt it would be prudent to investigate how critical reproduction of the mechanical axis was in the primary total knee replacement.

We assessed 100 primary total knee replacements performed in 1990. All case notes were reviewed looking for basic demographics, pathology, and clinical outcome. All cases had a long leg þlm weight bearing alignment þlm taken post operatively. These were digitised and then analysed using CAD software. From this the mechanical axis calculated.

Using this data the patients were divided into two groups. The þrst were within 3 degrees varus/valgus of the mechanical axis. The second were outside this range. These two groups were then correlated to clinical outcome.

Our results suggest that accurate reproduction of the mechanical axis improves clinical outcome and survi-vorship of the implant. Our data would support the use of intra operative computer navigation systems

Background and purpose: Development of minimal invasive operation techniques has given unicompartemental knee arthroplasty (UKA) renewed interest. Indications for use of UKA are however debated, and short-term advantages of UKA over total knee arthroplasty (TKA) should be weighed against the higher risk of reoperation. More knowledge on long term results of pain and function after knee arthroplasties is therefore needed and was the purpose of this study.

Methods: Patient-reported pain and function were collected at least two years after the operations in postal questionnaires from 1643 osteoarthritis patients reported to the Norwegian Arthroplasty Register with intact primary TKA (n=1271) or UKA (n=372). The questionnaire contained instruments for calculation of the knee specific Knee Osteoarthritis Outcome Score (KOOS), and for quality of life (EQ-5D, post- and pre-operative). 5 subscales from KOOS were used as outcome. To incorporate an outcome for anterior knee pain an additional subscale based on 7 questions from KOOS, clinically accepted to be related to such discomfort, was calculated. Pain and satisfaction from a visual analogue scale (VAS) were also used as outcomes together with improvement in EQ-5D index score. The outcomes were measured on a scale from 0 (worst) to 100 (best) units with an argued minimal perceptible clinical difference of 8–10 units. Group differences were analysed with multiple linear regression, adjusted for confounding by age, gender, Charnley category, time since operation and preoperative EQ-5D index score.

Results: UKA performed better than TKA for the KOOS subscales Activity in Daily Living (difference in mean outcome score =−3.4,p=0.02) and Sport and Recreation (difference =−4.4,p=0.02) and for Anterior Pain (difference=−4.5,p< 0.01). The difference was also significant for the outcome Pain(VAS) but now in favour of TKA (difference=3.3,p=0.02). Motivated by the discrepancy in the results of the pain related outcomes, Anterior Pain (UKA best), Pain(VAS) (TKA best) and Pain(KOOS) (no difference) further investigation of the questions (0=best to 4=worst) used for calculation of Pain(KOOS) and Anterior Pain were performed. Patients that had undergone UKA had more often pain from the knee (difference=0.26,p< 0.01), while they had less pain when they were bending the knee fully (difference=−0.37,p< 0.01) and less problems when squatting (difference=−0.25,p< 0.01).

Interpretation: Estimated differences did not reach the level of minimal perceptible clinical difference. There are however indication of differences in the way the two treatment groups experience knee related discomfort. Even though UKA offers a lower level of pain and less problems in activities involving bending of the knee, these patients seem to experience pain from the knee more often.

Aims. To compare rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications), and compare these with primary arthroplasty and re-revision arthroplasty. Methods. Patients undergoing primary knee arthroplasty were identified in the national Hospital Episode Statistics (HES) between 1 April 1997 to 31 March 2017. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes, including infection (undergoing surgery), pulmonary embolism, myocardial infarction, and stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications (e.g. loosening, instability, wear) were included in the elective indications cohort. Results. A total of 939,021 primary knee arthroplasty procedures were included (939,021 patients), of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% confidence interval (CI) 0.37 to 0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44 to 0.47). Revision arthroplasty for infection was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75 to 2.35; odds ratio (OR) 3.54; 95% CI 2.81 to 4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94 to 6.82; OR 6.23; 95% CI 4.39 to 8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. Conclusion. Patients undergoing revision arthroplasty for urgent indications (infection or fracture) are at higher risk of mortality and serious adverse events in comparison to primary knee arthroplasty and revision arthroplasty for elective indications. These findings will be important for patient consent and shared decision-making and should inform service design for this patient cohort. Cite this article: Bone Joint J 2021;103-B(10):1578–1585

Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty. Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort. 939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements

Abstract. Introduction. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision and compare these with primary knee arthroplasty. Methodology. Primary and revision arthroplasty procedures were identified in the national Hospital Episode Statistics and were linked by patient and side. A logistic regression model was used to investigate factors associated with 90-day mortality (primary outcome) and secondary serious adverse outcomes. Urgent indications for revision arthroplasty were defined as infection or fracture; other indications (e.g. loosening, instability, wear) were included in the elective cohort. Results. 939,021 primary knee arthroplasty and 40,584 revision cases were included. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of PE, MI, and stroke were observed in the infection and fracture cohort. Conclusion. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency with an anticipation for increased care requirements

Aims. The metabolic equivalent of task (MET) score examines patient performance in relation to energy expenditure before and after knee arthroplasty. This study assesses its use in a knee arthroplasty population in comparison with the widely used Oxford Knee Score (OKS) and EuroQol five-dimension index (EQ-5D), which are reported to be limited by ceiling effects. Methods. A total of 116 patients with OKS, EQ-5D, and MET scores before, and at least six months following, unilateral primary knee arthroplasty were identified from a database. Procedures were performed by a single surgeon between 2014 and 2019 consecutively. Scores were analyzed for normality, skewness, kurtosis, and the presence of ceiling/floor effects. Concurrent validity between the MET score, OKS, and EQ-5D was assessed using Spearman’s rank. Results. Postoperatively the OKS and EQ-5D demonstrated negative skews in distribution, with high kurtosis at six months and one year. The OKS demonstrated a ceiling effect at one year (15.7%) postoperatively. The EQ-5D demonstrated a ceiling effect at six months (30.2%) and one year (39.8%) postoperatively. The MET score did not demonstrate a skewed distribution or ceiling effect either at six months or one year postoperatively. Weak-moderate correlations were noted between the MET score and conventional scores at six months and one year postoperatively. Conclusion. In contrast to the OKS and EQ-5D, the MET score was normally distributed postoperatively with no ceiling effect. It is worth consideration as an arthroplasty outcome measure, particularly for patients with high expectations. Cite this article: Bone Jt Open 2023;4(3):129–137

Aims. The aim of this study was to describe the pattern of revision indications for unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) and any change to this pattern for UKA patients over the last 20 years, and to investigate potential associations to changes in surgical practice over time. Methods. All primary knee arthroplasty surgeries performed due to primary osteoarthritis and their revisions reported to the Danish Knee Arthroplasty Register from 1997 to 2017 were included. Complex surgeries were excluded. The data was linked to the National Patient Register and the Civil Registration System for comorbidity, mortality, and emigration status. TKAs were propensity score matched 4:1 to UKAs. Revision risks were compared using competing risk Cox proportional hazard regression with a shared γ frailty component. Results. Aseptic loosening (loosening) was the most common revision indication for both UKA (26.7%) and TKA (29.5%). Pain and disease progression accounted for 54.6% of the remaining UKA revisions. Infections and instability accounted for 56.1% of the remaining TKA revision. The incidence of revision due to loosening or pain decreased over the last decade, being the second and third least common indications in 2017. There was a decrease associated with fixation method for pain (hazard ratio (HR) 0.40; 95% confidence interval (CI) 0.17 to 0.94) and loosening (HR 0.29; 95% CI 0.10 to 0.81) for cementless compared to cemented, and units UKA usage for pain (HR 0.67, 95% CI 0.50 to 0.91), and loosening (HR 0.51; 95% CI 0.37 to 0.70) for high usage. Conclusion. The overall revision patterns for UKA and TKA for the last 20 years are comparable to previous published patterns. We found large changes to UKA revision patterns in the last decade, and with the current surgical practice, revision due to pain or loosening are significantly less likely. Cite this article: Bone Jt Open 2023;4(12):923–931

Aims. Our unit was identified as a negative outlier in the national patient-reported outcome measures (PROMs) programme, which has significant funding implications. As a centre that carries out a high volume of unicompartmental knee arthroplasty (UKA), our objectives were: 1) to determine whether the PROMs programme included primary UKA when calculating the gain in Oxford Knee Score (OKS); and 2) to determine the impact of excluding primary UKA on calculated OKS gains for primary knee arthroplasty. Materials and Methods. National PROMs data from England (2012 to 2016) were analyzed. Inclusion of UKA cases in the national PROMs programme was determined using clinical codes. Local OKS gain was calculated for UKA and TKA and compared with the published PROMs results for 2012/13. Results. Use of the recommended codes for primary UKA excluded 99.6% of UKAs locally and 97% nationally from PROMs programme analysis. Inclusion of primary UKAs in PROMs analysis improved our OKS gain from 15.1 (below average) to 16.3 (above average) for 2012/13 for primary knee arthroplasty. Conclusion. Exclusion of UKA patients from the PROMs programme is a nationwide issue that potentially introduces bias when comparing OKS gain between centres. Where commissioning decisions are based on routinely collected data, it is imperative that the underlying methodology is appropriate to generate valid results

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. Methods. Patient demographic details, BMI, American Society of Anesthesiologists (ASA) grade, indication for revision, surgical approach, surgeon grade, implant type (fixed and rotating), time of revision from primary implantation, and re-revision if undertaken were obtained from the National Joint Registry data for England, Wales, Northern Ireland, and the Isle of Man over an 18-year period (2003 to 2021). Results. There were 3,855 patient episodes analyzed with a median age of 73 years (interquartile range (IQR) 66 to 80), and the majority were female (n = 2,480, 64.3%). The median time to revision from primary knee arthroplasty was 1,219 days (IQR 579 to 2,422). Younger age (p < 0.001), decreasing ASA grade (p < 0.001), and indications for revision of sepsis (p < 0.001), unexplained pain (p < 0.001), non-polyethylene wear (p < 0.001), and malalignment (p < 0.001) were all associated with an earlier time to revision from primary implantation. The median follow-up was 4.56 years (range 0.00 to 17.52), during which there were 410 re-revisions. The overall unadjusted probability of re-revision for all revision HKAs at one, five, and ten years after surgery were 2.7% (95% confidence interval (CI) 2.2 to 3.3), 10.7% (95% CI 9.6 to 11.9), and 16.2% (95% CI 14.5 to 17.9), respectively. Male sex (p < 0.001), younger age (p < 0.001), revision for septic indications (p < 0.001) or implant fracture (p = 0.010), a fixed hinge (p < 0.001), or surgery performed by a non-consultant grade (p = 0.023) were independently associated with an increased risk of re-revision. Conclusion. There were several factors associated with time to first revision. The re-revision rate was 16.2% at ten years; however, the risk factors associated with an increased risk of re-revision could be used to counsel patients regarding their outcome. Cite this article: Bone Joint J 2023;105-B(1):47–55

Aims. The purpose is to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model. Methods. A multicentre prospective randomized controlled trial was conducted evaluating the use of a smartphone-based care management system for primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA). Patients in the control group (n = 244) received the respective institution’s standard of care with formal physiotherapy. The treatment group (n = 208) were provided a smartwatch and smartphone application. Early outcomes assessed included 90-day knee range of movement, EuroQoL five-dimension five-level score, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score, 30-day single leg stance (SLS) time, Time up and Go (TUG) time, and need for manipulation under anaesthesia (MUA). Results. Overall, 90-day mean flexion was not significantly different between the control (121° (SD 11.7°)) and treatment groups (121. o. ; p = 0.559); 90-day mean SLS was 22.7 seconds (SD 9.8) in controls and 24.3 seconds (SD 20.8) in treatment (p = 0.519); 90-day mean TUG times were 10.1 seconds (SD 4.8) in control and 9.3 seconds (SD 3.3) in treatment (p = 0.139). Mean KOOS JR scores were significantly different between control group (73.6 (SD 13.4)) and treatment group (70.4 (SD 12.6); p = 0.026). MUAs were performed in nine (3.7%) patients in the control group and four (1.9%) in the treatment group (p = 0.398). Physiotherapy was performed by 230 (94.4%) of control group and 123 (59.3%) of treatment group (p < 0.001). There were no significant differences between groups in postoperative urgent care visits, or readmissions within 90 days, with significantly fewer emergency department visits in the treatment group (16 (8.2%) vs five (2.5%), p = 0.014). Conclusion. The use of the smartwatch/smartphone care platform demonstrated non-inferiority of clinically significant outcomes to traditional care models, while requiring significantly less postoperative physiotherapy and fewer emergency department visits. This platform could aid in decreasing postoperative costs, while improving patient engagement and communication with the healthcare team. Cite this article: Bone Joint J 2021;103-B(6 Supple A):3–12

In 1975, Sweden started registering primary knee replacement surgeries based on the personal identity number. Individual-based registrations of primary total hip replacements started in 1992 and for hemiarthroplasties the registration started in 2006. The completeness of these registrations is estimated at 98% during the last 10-year period. The long history and high completeness allow for accurate calculations of population-based prevalence of joint replacement and trends over time. We used all data on primary joint replacements available in the Swedish Arthroplasty Register. The prevalence was calculated using number of alive patients with 1) at least one joint replacement 2) at least one hip replacement 3) at least one knee replacement at the end of each year from 2010 – 2021. Publicly available population numbers were retrieved from Statistics Sweden. We calculated total prevalence and prevalence per age in years. By the end of 2021, 3.2% of the Swedish population had at least one hip or knee replacement. This was an increase from 2.5% in 2010. Among 80-year-old, the prevalence was 17.5% for any joint replacement. For both hip and knee replacement and all ages, the prevalence was higher for women. For knee replacement, the 2021 prevalence peaked at the age of 89 (9,4%) while the prevalence continuously increased with age for hip replacements. A considerable proportion of the Swedish elderly population is living with at least one hip or knee replacement. The prevalence has increased during the last 12-year period for both hips and knees. An increasing prevalence may also affect the incidence of fractures and infections. Knowledge about the prevalence is fundamental for planning future demand for primary and revision hip and knee replacement

Aims. Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements. Methods. We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma. Results. Of the 14,584 included patients, the most commonly performed surgeries were knee arthroplasty (24.8%), hip arthroplasty (24.6%), and hip fracture surgery (17.4%). A total of 10.3% of patients received RBC transfusion; the proportion of patients receiving RBC transfusions varied widely based on the surgical subgroup (0.0% to 33.1%). Primary knee arthroplasty and hip arthroplasty, the two most common surgeries, were associated with in-hospital transfusion frequencies of 2.8% and 4.5%, respectively. RBC transfusion occurred in 25.0% of hip fracture surgeries, accounting for the greatest total number of RBC units transfused in our cohort (38.0% of all transfused RBC units). Platelet and plasma transfusions were uncommon. Conclusion. Orthopaedic surgeries were associated with variable rates of transfusion. The rate of RBC transfusion is highly dependent on the surgery type. Identifying surgeries with the highest transfusion rates, and further evaluation of factors that contribute to transfusion in identified at-risk populations, can serve to inform perioperative planning and blood bank requirements, and facilitate pre-emptive transfusion mitigation strategies. Cite this article: Bone Jt Open 2021;2(10):850–857

Abstract. Introduction. The role of patellar resurfacing in total knee arthroplasty remains controversial. We questioned the effect of patellar resurfacing on the early and late revision rates after total knee arthroplasty. Materials and Methods. We analysed the data of cumulative revisions of primary knee replacement from the NJR 19th Annual Report. NJR included secondary patellar resurfacing as a revision. We compared differences in the 3-year and 15-year revision rates between the patellar resurfacing and non-resurfacing for the different combinations of total knee replacements using a paired t-test. We performed subgroup analysis for the five combinations with the highest volumes. Results. Twenty-seven implant combinations had the 15-year revision rates reported. Patellar resurfacing group had lower mean 3-year revision rate of 1.68 (SD 0.7) compared to 2.02 (SD 0.9) in non-resurfacing group (p=0.05). However, 15-year revision rate was similar between the two groups (mean 5.7, SD 2.1 vs. mean 5.7, SD 2.2; p = 0.46). High volume implants showed that two combinations (NexGen CR and PS) had similar revision rates at 3 and 15 years between resurfacing and non-resurfacing groups. Three combinations (PFC Sigma CR and PS and Genesis 2 CR) had higher revision rate in non-resurfacing group at 3 years (p=0.01) and the difference persisted at 15 years (p=0.05). Conclusions. Although revision rate in total knee arthroplasty was higher without patellar resurfacing at 3 years, at 15 years the difference was not significant. However, the higher revision without patellar resurfacing can be prosthetic combination specific which surgeons need to be aware of

The aim of this retrospective cohort study was to investigate the reasons for total knee arthroplasty (TKA) revisions at a tertiary hospital over a four-year period. The study aimed to identify the primary causes of TKA revisions and shed light on the implications for patient care and outcomes. The study included 31 patients who underwent revisions after primary knee arthroplasty between January 2017 and December 2020. A retrospective approach was employed, utilizing medical records and radiological findings to identify the reasons for TKA revisions. The study excluded oncology patients to focus on non-oncologic indications for revision surgeries. Patient demographics, including age and gender, were recorded. Data analysis involved categorizing the reasons for revision based on clinical assessments and radiological evidence. Among the 31 patients included in the study, 9 were males and 22 were females. The age of the patients ranged from 43 to 81, with a median age of 65 and an interquartile range of 18.5. The primary reasons for TKA revisions were identified as aseptic loosening (10 cases) and prosthetic joint infection (PJI) (13 cases). Additional reasons included revision from surgitech hemicap (1 case), patella osteoarthritis (1 case), stiffness (2 cases), patella maltracking (2 cases), periprosthetic fracture (1 case), and patella resurfacing (1 case). The findings of this retrospective cohort study highlight aseptic loosening and PJI as the leading causes of TKA revisions in the examined patient population. These results emphasize the importance of optimizing surgical techniques, implant selection, and infection control measures to reduce the incidence of TKA revisions. Future research efforts should focus on preventive strategies to enhance patient outcomes and mitigate the need for revision surgeries in TKA procedures

Patient-reported outcome measures (PROMs) have failed to highlight differences in function or outcome when comparing knee replacement designs and implantation techniques. Ankle-worn inertial measurement units (IMUs) can be used to remotely measure and monitor the bi-lateral impact load of patients, augmenting traditional PROMs with objective data. The aim of this study was to compare IMU-based impact loads with PROMs in patients who had undergone conventional total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and robotic-assisted TKA (RA-TKA). 77 patients undergoing primary knee arthroplasty (29 RA-TKA, 37 TKA, and 11 UKA) for osteoarthritis were prospectively enrolled. Remote patient monitoring was performed pre-operatively, then weekly from post-operative weeks two to six using ankle-worn IMUs and PROMs. IMU-based outcomes included: cumulative impact load, bone stimulus, and impact load asymmetry. PROMs scores included: Oxford Knee Score (OKS), EuroQol Five-dimension with EuroQol visual analogue scale, and the Forgotten Joint Score. On average, patients showed improved impact load asymmetry by 67% (p=0.001), bone stimulus by 41% (p<0.001), and cumulative impact load by 121% (p=0.035) between post-operative week two and six. Differences in IMU-based outcomes were observed in the initial six weeks post-operatively between surgical procedures. The mean change scores for OKS were 7.5 (RA-TKA), 11.4 (TKA), and 11.2 (UKA) over the early post-operative period (p=0.144). Improvements in OKS were consistent with IMU outcomes in the RA-TKA group, however, conventional TKA and UKA groups did not reflect the same trend in improvement as OKS, demonstrating a functional decline. Our data illustrate that PROMs do not necessarily align with patient function, with some patients reporting good PROMs, yet show a decline in cumulative impact load or load asymmetry. These data also provide evidence for a difference in the functional outcome of TKA and UKA patients that might be overlooked by using PROMs alone

Malnutrition is considered a risk factor for postoperative complications in total hip and knee arthroplasty, though prospective studies investigating this assumption are lacking. The aim of this study was to prospectively analyse the 90-day postoperative complications, postoperative length of stay (LOS) and readmission rates of patients undergoing primary total hip and total kneearthroplasty using albumin, total lymphocyte count (TLC) and transferrin as serum markers of potential malnutrition. 603 primary hip and 823 primary knee arthroplasties over a 3-year period from a single centre wereprospectively analysed. BMI, demographic and comorbidity data were recorded. Complications werecategorised as surgical site infection, venous thromboembolism (deep vein thrombosis andpulmonary embolus), implant related (such as dislocation), and non-implant related (such aspneumonia). Outcomes were compared between groups, with malnutrition defined as serumalbumin <3.5g/dL, transferrin <200 mg/dL, or TLC <1,500 cells/mm³. Potential malnutrition was present in 9.3% of the study population. This group experienced a longeraverage LOS at 6.5 days compared to the normal albumin group at 5.0 days (p=0.003). Surgical siteinfection rate was higher in the malnourished group (12.5 vs 7.8%, p=0.02). There was no differencebetween the two groups in implant related complications (0.8 vs 1.0%, p=0.95) medicalcomplications (7.8 vs 13.3%, p=0.17), rate of venous thromboembolism (2.3 vs 2.7%) or 90-dayreadmission rate (14.1 vs 17.0%, p=0.56). TLC and transferrin were not predictive of any of theprimary outcomes measured (p<0.05). Pacific Island (p<0.001), Indian (p=0.02) and Asian (p=0.02) patients had lower albumin than NZ European. This study demonstrates an association between low albumin levels and increased postoperativeLOS and surgical site infection in total joint arthroplasty, providing rationale for consideration ofpreoperative nutritional screening and optimisation

Abstract. Background. 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. Methods. 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. Results. The 1,000 mUKA cohort represented 55% of all primary knee replacements in the period, with an average age of 67.7 years and a 54%/46% male/female split. There were 17 revisions (11 for arthritis progression, 4 infections, 1 dislocation and 1 aseptic loosening). The 10-year survival was 98% (44 at risk in 10th year). One patient sustained a periprosthetic fracture at 3 weeks, treated with buttress plate fixation. Discussion. This is the first detailed series reporting the long-term outcome of the cementless Oxford mUKA implanted using microplasty instrumentation. There was a low failure rate, with only one revision for aseptic loosening. Lateral progression was the commonest cause for revision, with an incidence of 1%. This report provides evidence that the combination of evidence-based indications, well-designed instrumentation and cementless fixation can provide excellent long-term survival for the Oxford mUKA in treating AMOA

Abstract. Introduction. This multi-centre randomised controlled trial evaluated the clinical and cost effectiveness of liposomal bupivacaine for pain and recovery following knee replacement. Methodology. 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. Results. Primary analysis found no difference in pain VAS AUC 6 to 72hours between liposomal bupivacaine and control (MD -21.5 (97.5% CI -46.8 to 3.8; p=0.057)), nor the QoR-40 at 72hours (MD 0.54, 97.5% CI -2.05 to 3.13, p=0.643). Analyses of pain VAS and QoR-40 scores on days 0, 1, 2 and 3 demonstrated only one significant difference, with the liposomal bupivacaine arm having lower pain scores the evening of surgery (day0; MD -0.54, 97.5% CI -1.07 to -0.02; p=0.021). No difference in cumulative opioid consumption or functional outcome at 6weeks, 6months or 1year was detected. Heath economic analysis found liposomal bupivacaine to be less effective in terms of QALYs as well as more costly. No difference in adverse events between arms was identified. Conclusion. This is the largest RCT evaluating the clinical and cost effectiveness of liposomal bupivacaine It found that compared to bupivacaine hydrochloride local infiltration of liposomal bupivacaine at the surgical site does not provide any clinical or cost benefit for knee replacement and therefore should not be routinely used

Aims. As the peak of the COVID-19 pandemic passes, the challenge shifts to safe resumption of routine medical services, including elective orthopaedic surgery. Protocols including pre-operative self-isolation, COVID-19 testing, and surgery at a non-COVID-19 site have been developed to minimize risk of transmission. Despite this, it is likely that many patients will want to delay surgery for fear of contracting COVID-19. The aim of this study is to identify the number of patients who still want to proceed with planned elective orthopaedic surgery in this current environment. Methods. This is a prospective, single surgeon study of 102 patients who were on the waiting list for an elective hip or knee procedure during the COVID-19 pandemic. Baseline characteristics including age, ASA grade, COVID-19 risk, procedure type, surgical priority, and admission type were recorded. The primary outcome was patient consent to continue with planned surgical care after resumption of elective orthopaedic services. Subgroup analysis was also performed to determine if any specific patient factors influenced the decision to proceed with surgery. Results. Overall, 58 patients (56.8%) wanted to continue with planned surgical care at the earliest possibility. Patients classified as ASA I and ASA II were more likely to agree to surgery (60.5% and 60.0%, respectively) compared to ASA III and ASA IV patients (44.4% and 0.0%, respectively) (p = 0.01). In addition, patients undergoing soft tissue knee surgery were more likely to consent to surgery (90.0%) compared to patients undergoing primary hip arthroplasty (68.6%), primary knee arthroplasty (48.7%), revision hip or knee arthroplasty (0.0%), or hip and knee injections (43.8%) (p = 0.03). Conclusion. Restarting elective orthopaedic services during the COVID-19 pandemic remains a significant challenge. Given the uncertain environment, it is unsurprising that only 56% of patients were prepared to continue with their planned surgical care upon resumption of elective services. Cite this article: Bone Joint Open 2020;1-6:267–271

The rising prevalence of osteoarthritis, associated with an ageing population, is expected to deliver increasing demand across Scotland for primary hip and knee arthroplasty in the future. Understanding the scale of potential change to operative workflow is essential to ensure adequate provision of services, and prevent prolonged waiting times that can cause patient harm. We therefore set out to provide projections of future primary hip and knee arthroplasty out to 2038 utilising historical trend data (2008–2018) from the Scottish Arthroplasty Project. All analyses were performed using the Holt's exponential smoothing projection method with the forecast package in R statistics. Results were adjusted for projected future population estimates provided by National Records of Scotland. Independent age & sex group predictions were also performed. All results are presented per 100,000 population at-risk per year (/100k/year). The predicted rise of primary hip arthroplasty for all ages is from 120/100k/year in 2018 to 152/100k/year in 2038, a 27% increase. The predicted rise of primary knee arthroplasty for all ages is from 164/100k/year in 2018 to 220/100k/year in 2038, a 34% increase. Based on a static 3 day length of stay average this would see 4280 additional patient bed days for hips, and 7392 for knees, required nationally per year by 2038. The associated supplementary cost to the NHS is anticipated to be around £21 million per annum. Knowledge of increasing resource utilisation and cost associated with predicted future demand for primary hip and knee arthroplasty provides key information for service organisation and delivery

The current standard of practice following knee arthroplasty is to demonstrate the appropriate alignment of knee replacements using knee radiographs. Recent studies have suggested that standard knee radiographs provide adequate accuracy for tibial prosthesis alignment assessment as compared with long knee view radiographs which are more technically demanding and carry greater radiation exposure. In this study, we aim to address whether alignment measured on standard knee radiographs are reliable and reproducible over time. We examined a cohort of 80 patients 37 male (46%), 43 females (54%), mean age = 68 years) who underwent total knee arthroplasty (TKA). Standard knee anteroposterior radiographs performed within 2 days following surgery were compared to standard knee anteroposterior radiographs taken 1 year following the surgery in patients with well-functioning prosthesis. Tibial prosthesis alignment angles between the longitude of the tibial shaft and the tibial baseplate were calculated using Centricity Enterprise Web V3.0 software. The data was examined using R software. In well-functioning primary knee arthroplasties, tibial prosthesis alignment angles measured in the 1-year follow-up standard view knee radiographs were found to deviate from measurements obtained with the same radiographic specifications in the immediate post-operative period. A significant mean percentage difference was found between the two radiographs. Long knee view radiographs may be required in order to accurately assess tibial prothesis alignment following total knee arthroplasty

In the UK and USA in 2016 more than 263,000 primary knee replacements were performed. Around 20% of patients report chronic post-surgical pain (CPSP) at three or more months after total knee replacement (TKR). A large proportion of adults with all types of chronic musculoskeletal pain do not use services for a number of reasons, despite being in constant or daily pain. Given the high prevalence of CPSP, there is potentially a large hidden population with an unexpressed need for care, experiencing ongoing pain and disability; understanding why they do not use health services may herald further insight into why many remain dissatisfied with knee replacement surgery. The aim of this study is to understand why some people with CPSP after TKR do not access services or make little use of healthcare. We conducted face-to-face in-depth interviews with 34 patients from 2 high-volume orthopaedic hospitals in England, to investigate their experience of long-term pain after knee replacement; their knowledge and understanding of CPSP; and their decisions about consulting for CPSP. The sample size was based on achievement of saturation and participants provided written informed consent. Interviews were transcribed and analysed using an inductive thematic approach with double coding for rigor. Ethical approval for the study was granted by the West Midlands Solihull Research Ethics Committee (15/WM/0469). A core theme within the analysis suggests that participants do not seek healthcare because they believe that nothing further can be done, either by themselves or by healthcare professionals. Surgeons' satisfaction with the knee surgery and reassurances that pain would improve, left patients feeling uncertain about whether to re-consult, and some assumed that further consultation could lead to further surgery or medication, which they wish to avoid. Some participants' comorbidities took precedence over their knee pain when seeking healthcare. Others felt they had received their “share” of healthcare resources and that others were more deserving of treatment. People's descriptions of pain varied, from dull, or aching to shooting pains. Many described their pain as “discomfort” rather than pain. The majority described pain that was better than their pre-surgical pain, though others described pain that was worse, which they believed to be nerve damage. Many expressed disappointment in the outcome of their TKR. Expectations of pain varied, where most had expected some post-surgical pain, others underestimated it, and some had expected to be completely pain free following their TKR. Our analysis suggests that the reasons that some people with CPSP after TKR do not consult are varied and complex, spanning psychosocial, structural, moral, and organisational domains. There was an overriding sense that further consultation would be futile or may lead to unwanted treatment. Results suggest that improved information for patients about CPSP and appropriate post-surgical healthcare services may help patients and clinicians to manage this condition more effectively

Aims

The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery.

Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses. 1. In a knee simulator study, Kretzer. 2. , demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design). In primary knees, we did not observe an increase in serum metal ion levels at 3, 6 or 12 months. Two patients with a hip arthroplasty had elevated preTKA Co and Cr levels. There was no difference between unilateral and bilateral knee prostheses. In the revision group, elevated pre-revision levels were found in 2 failures for implant loosening. In both cases, ion levels decreased postoperatively. In revisions with a standard TKA, there was no significant increase in metal ions compared to primary knee arthroplasty. RHK were associated with a significant increase in Co levels even at short-term (3–12 months). The megaprosthesis group had the highest metal ion levels and showed a significant increase in Co and Cr with time in patients followed prospectively. With the current data, we could not demonstrate a correlation between metal ion levels, size of the implant or length of time in situ. In primary knee arthroplasty with a standard TKA or UKA, metal ion levels were not elevated till one year postoperatively. This suggests a different mechanism of metal ion release in comparison to metal-on-metal hip arthroplasties. In two cases of revision for implant loosening, pre-revision levels were elevated, possibly associated with component wear, and decreased after revision. With RHK, slightly elevated ion levels were found prospectively. Megaprostheses had significantly elevated Co and Cr levels, due to corrosion of large metallic surfaces and/or wear of components which were not perfectly aligned during difficult reconstruction after tumour resection. Further research is needed to assess the clinical relevance of metal ion levels in knee arthroplasty

Aim. In surgeries on patients with advanced ligament instabilities or severe bone defects modern-generation of rotating hinged knee prostheses are one of the main options. The objective of our study is to evaluate the mid-term functional results and complications of several surgeries using this form of prosthesis. Material and Method. The rotating hinged knee prosthesis (RHKP) was applied to 208 knees of 204 patients in primary surgeries between September 2009 and December 2017, the minimum followup was 15 months (mean, 65 months; range, 15–115 months). Of the total number of female patients there were 152 (74.5%), men − 52 (25.5%). The average age of the patients was 64,6 years (from 32 to 85). The main indications for using RHKP were severe varus deformity with flexion contracture in 107 knees (51,4%), severe valgus deformity (from 20 to 50 degrees) in 54 knees (26,0 %), severe ligamentous deficiencies in 24 knees (11,5%) and ankylosis in the flexion position in 23 cases (11,1%). Patients were evaluated clinically (Knee Society score) and radiographically (positions of components, signs of loosening, bone loss). Results. The average Knee Society Knee Scores, and Knee Society Functional Scores were 27, and 18, respectively, before the surgery; and 86, and 77 in the final post-surgery follow-ups. In addition, the average range of motion increased from the pre-operative level of 46 to 104 degrees at the final evaluation. Four patients (2%) had various complications after the surgery : two patients had deep infection, in one case took place fracture of the hinge mechanism and in one - post-operative rupture of the patellar tendon. Conclusions. Primary knee arthroplasty using RKHP can be successful in cases with advanced ligament instability or severe bone defects. Modern-generation of the kinematic rotating-hinge total knee prostheses allow to achieve in difficult primary cases the same consistently good results as commonly used constructions in standard situations

Introduction. Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses. 1. In a knee simulator study, Kretzer. 2. , demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. Patients and Methods. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients) (Fig 1). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design). Results (Fig 2 and 3). In primary knees, we did not observe an increase in serum metal ion levels at 3, 6 or 12 months. Two patients with a hip arthroplasty had elevated preTKA Co and Cr levels. There was no difference between unilateral and bilateral knee prostheses. In the revision group, elevated pre-revision levels were found in 2 failures for implant loosening. In both cases, ion levels decreased postoperatively. In revisions with a standard TKA, there was no significant increase in metal ions compared to primary knee arthroplasty. RHK were associated with a significant increase in Co levels even at short-term (3–12 months). The megaprosthesis group had the highest metal ion levels and showed a significant increase in Co and Cr with time in patients followed prospectively. With the current data, we could not demonstrate a correlation between metal ion levels, size of the implant or length of time in situ. Discussion. In primary knee arthroplasty with a standard TKA or UKA, metal ion levels were not elevated till one year postoperatively. This suggests a different mechanism of metal ion release in comparison to metal-on-metal hip arthroplasties. In two cases of revision for implant loosening, pre-revision levels were elevated, possibly associated with component wear, and decreased after revision. With RHK, slightly elevated ion levels were found prospectively. Megaprostheses had significantly elevated Co and Cr levels, due to corrosion of large metallic surfaces and/or wear of components which were not perfectly aligned during difficult reconstruction after tumour resection. Further research is needed to assess the clinical relevance of metal ion levels in knee arthroplasty. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Aim. The primary aim of this study was to examine whether the use of iodine impregnated incision drape (IIID) decreased the risk of periprosthetic joint infections (PJIs). The secondary aim was to investigate whether intraoperative contamination could predict postoperative infection. PJI is a devastating incident for the patients and in a population that is getting older and the incidence of arthroplasty surgery is rising it is vital to keep the infection rate as low as possible. Despite prophylactic measures as pre-operative decontamination, antisepsis and prophylactic antibiotics the infection rate has been constant at 1–2%. Method. We performed a transregional, prospective, randomized two arm study (IIID vs control group) of 1187 patients undergoing primary knee arthroplasty surgery. A database with patient demographics and surgical observations was established with the purpose of following the patients for ten years. Patients, who developed an infection within the first year of surgery were analyzed for correlation with the intraoperative bacterial findings and the use of IIID. Results. 31/1187 (3.6%) patients were re-operated during the follow-up period. 18/1187 (1.5%) patients were deemed infected and received antibiotic treatment. 9/18 patients deemed infected were male. Of the 18 infected patients 2 were contaminated at the primary surgery. Chi square test showed no correlation between contamination and infection (OR 0.97, 95% CI 0.38–2.46, p=0.95). 9 of the 18 infected patients were operated with IIID at the primary surgery. No correlation was found between the use of IIID at primary surgery and subsequent infection (OR 0.86, 95% CI 0.20–3.79, p=1). Conclusions. We found no effect of the use of IIID and subsequent development of PJI. Nor did we find a correlation between the intraoperative contamination and development of PJI within the first year of follow-up. Acknowledgements. University of Copenhagen and 3M Health Care (St. Paul, Minnesota) funded the study. 3M did not participate in the design of the study, data collection, data analysis or data interpretation

Introduction. Recent focus has queried whether of deoxyribonucleic acid (DNA) sequencing modalities of bacterial DNA found in periarticular fluid and tissues will improve in periprosthetic joint infection (PJI) diagnosis and organism identification diagnostic accuracy for periprosthetic joint infection The purpose of this study was to compare the diagnostic accuracy of next generation sequencing (NGS) to polymerase chain reaction (PCR) multiplex, and culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al. [1] in the diagnosis of periprosthetic knee infections. Methods. In this retrospective study, aspirate or tissue samples were collected in 70 revision and 58 primary knee arthroplasties for routine diagnostic workup for PJI and sent to the laboratory for NGS and PCR multiplex. Concordance along with statistical differences between diagnostic studies were calculated using Chi-squared test for categorical data. Results. When comparing to the MSIS criteria, concordance was 78.1% for NGS, 66.4% for PCR, and 85.9% for culture (p<0.001). There was no significant difference based on prior infection (p=0.825), or sample collection method (tissue swab or synovial fluid) (p=0.986). Fifteen samples were culture positive and NGS negative, of which 10 (66.7%) met both criteria for PJI. Thirteen patients were culture negative but NGS positive, of which 2 (15.4%) met both criteria. Concordance was 100% between the MSIS criteria and criteria proposed by Parvizi et al. [1]. Conclusion. In this initial cohort NGS was more accurate than 16s subunit PCR techniques, but less accurate than culture in the diagnosis of PJI determining the presence or absence of PJI. What is not clear is how NGS will perform against culture in terms of identifying the specific bacterial strain. Currently, laboratory tests used for either criteria for PJI diagnosis should be obtained regardless of NGS along with the overall clinical picture to help guide decision making for PJI treatment. For figures, tables, or references, please contact authors directly

Management of severe bone loss in total knee arthroplasty presents a formidable challenge. This situation may arise in neglected primary knee arthroplasty with large deformities and attritional bone loss, in revision situations where osteolysis and loosening have caused large areas of bone loss and in tumor situations. Another area of large bone loss is frequently seen in periprosthetic fractures. Trabecular metal (TM) with its dodecahedron configuration and modulus of elasticity between cortical and cancellous bone offers an excellent bail out option in the management of these very difficult situations. Severe bone loss in the distal femur and proximal tibia lend themselves to receiving the TM cones. The host bone surfaces need to be prepared to receive these cones using a high speed burr. The cones acts as a filler with an interference fit through which the stemmed implant can be introduced and cemented. All areas of bone void is filled with morselised cancellous bone fragments. We present our experience of 64 TM cones (28 femoral, 36 tibial cones) over a 10-year period and our results and outcomes for the same. We have had to revise only one patient for recurrence of the tumor for which the cone was implanted in the first place. We also describe our technique of using two stacked cones for massive distal femoral bone loss and its outcomes. We found excellent osteointegration and new host bone formation around the TM construct. The purported role of possible resistance to infection in situations using the TM cones is also discussed. In summary we believe that the use of the TM cones offers an excellent alternative to massive allografts, custom and/or tumor implants in the management of massive bone loss situations

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.

Aims

Metal particles detached from metal-on-metal hip prostheses (MoM-THA) have been shown to cause inflammation and destruction of tissues. To further explore this, we investigated the histopathology (aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL) score) and metal concentrations of the periprosthetic tissues obtained from patients who underwent revision knee arthroplasty. We also aimed to investigate whether accumulated metal debris was associated with ALVAL-type reactions in the synovium.

Aims

Routinely collected patient-reported outcome measures (PROMs) have been useful to quantify and quality-assess provision of total hip arthroplasty (THA) and total knee arthroplasty (TKA) in the UK for the past decade. This study aimed to explore whether the outcome following primary THA and TKA had improved over the past seven years.

The June 2023 Research Roundup³⁶⁰ looks at: Characterizing recurrent infections after one-stage revision for periprosthetic joint infection of the knee; Predicted waiting times for orthopaedic surgery: an urgent need to address the deficit in capacity; Vascular impulse technology versus elevation for reducing the swelling of upper and lower limb joint fractures; Desperate patients will accept higher risks; How long does it take to find a positive culture in periprosthetic joint infection?

Background. The Enhanced Recovery Programme (ERP) is an evidence based initiative aimed at speeding up patient recovery after major surgery and improving their outcomes. The Royal National Orthopaedic Hospital, Stanmore (RNOH) is a specialist orthopaedic and implemented an ERP for primary knee arthroplasties from October 2010. Aims. To analyse the initial results of patients participating in our ERP for primary knee arthroplasty to identify what factors predict their Length of Stay (LoS) and establish where changes can be made to improve outcomes further. Method. We interrogated our prospective ERP database and determined which patients achieved and which ones exceeded the 5-day LoS target. We then performed a further retrospective notes review to gather supplementary information including non-modifiable patient factors to identify factors which influenced their LoS. Results. 261 patients participated in the Knee ERP at the RNOH between October 2010 and December 2011 including patients undergoing complex procedures and bilateral procedures during the same in-patient episode. Mean age was 64 years (32–85 years). Mean LoS was 6.1 days (2–29 days). ASA grade and attendance at the multidisciplinary Joint School all had a positive influence on the LoS, particularly when combined. The day of mobilisation had the greatest correlation with those mobilising early. Mean LoS was 2.8 (Day 0), 4.41 (Day 1), 6.38 (Day 2), 9.23 (Day 3) and 12.95 (Day 4 or later). Conclusion. Identifying and targeting modifiable variables can further improve the outcomes for this particular group of patients. ASA grade and attendance at the multidisciplinary Joint School are among the positive influences on patient LoS. Adjusting analgesia to reduce unwanted effects may facilitate earlier engagement with the physiotherapy service and thus earlier mobilisation. Early results suggest encouraging patients to attend Joint School with subsequently early postoperative mobilisation can positively influence safe return to the home environment

Aims

This study aimed to investigate the estimated change in primary and revision arthroplasty rate in the Netherlands and Denmark for hips, knees, and shoulders during the COVID-19 pandemic in 2020 (COVID-period). Additional points of focus included the comparison of patient characteristics and hospital type (2019 vs COVID-period), and the estimated loss of quality-adjusted life years (QALYs) and impact on waiting lists.

The February 2023 Knee Roundup³⁶⁰ looks at: Machine-learning models: are all complications predictable?; Positive cultures can be safely ignored in revision arthroplasty patients that do not meet the 2018 International Consensus Meeting Criteria; Spinal versus general anaesthesia in contemporary primary total knee arthroplasty; Preoperative pain and early arthritis are associated with poor outcomes in total knee arthroplasty; Risk factors for infection and revision surgery following patellar tendon and quadriceps tendon repairs; Supervised versus unsupervised rehabilitation following total knee arthroplasty; Kinematic alignment has similar outcomes to mechanical alignment: a systematic review and meta-analysis; Lifetime risk of revision after knee arthroplasty influenced by age, sex, and indication; Risk factors for knee osteoarthritis after traumatic knee injury.

Aims

The impact of a diaphyseal femoral deformity on knee alignment varies according to its severity and localization. The aims of this study were to determine a method of assessing the impact of diaphyseal femoral deformities on knee alignment for the varus knee, and to evaluate the reliability and the reproducibility of this method in a large cohort of osteoarthritic patients.

Aims

To map the Oxford Knee Score (OKS) and High Activity Arthroplasty Score (HAAS) items to a common scale, and to investigate the psychometric properties of this new scale for the measurement of knee health.

Periprosthetic joint infection (PJI) is one of the most feared complications following total knee arthroplasty (TKA). Despite improved peri-operative antibiotic management and local antibiotic-loaded bone cement PJI is reported in about 0.5–1.9 % of primary knee replacement. In case of revision knee arthroplasty the infection rate even occurs at about 8–10 %. Depending on an acute or late PJI several surgical methods are used to treat the infection. However, suffering of a late PJI, the only surgical procedure remains the exchange of the TKA in combination with a radical debridement and removal of all foreign material. In order to achieve complete debridement of the joint, the soft tissue must be radically excised. Frequently, the debridement of the posterior capsule causes severe difficulties, therefore it might be necessary to resect the collateral ligaments to be able to reach the posterior parts of the capsule. But this necessitates the use of a higher level of constraint such as a rotating or total hinge and fully cemented long stemmed revision implants. Furthermore, due to the cemented stems, a sufficient amount of antibiotic-loaded cement may be delivered to the bone as topical therapy. Up to now, several studies have shown excellent functional long-term results for hinge knee prostheses after PJI and a very good infection control rate. Advantages of the hinge knee prosthesis in cases of PJI are the opportunity for a complete debridement especially while addressing the posterior capsule after resection of the collateral ligaments and for delivering antibiotic-loaded bone cement at the stems of the prosthesis for topic therapy. Disadvantages are the need for a higher level of constraint and a possible higher blood loss due to the radical debridement

Compromised patellar bone stock poses significant the chnical problems in primary and revision knee arthroplasty. In these situations, traditional approaches have included: non resurfacing, patellectomy, patellar bone grafting, ‘Gull-Wing’ osteotomy. A new material (Trabecular Metal) fabricated using a tantalum metal and vapor deposition techhnique that create a metallic strut configuration with 80%porosity, and physical and mechanical properties similar to bone has been introduced. The authors studied the short-term results following patellar resurfacing using trabecular metal patella in primary and revision total knee arhroplasty (TKA). Nine patients undergoing primary (2 cases) or revision (7 cases) TKA with the use of a trabecular metal patella were evaluated at a mean of 16 months follow-up. All patients had marked patellar bone deficiency precluding resurfacing with a standard cemented patellar button. The all polyethylene patela was cemented into the trabecular metal base and the remaining patella bone stock; additional fixation was provided by # 2 non absorbable sutures through the peripheral holes on the metal shell. Revision TKA may be complicated by severe patellar bone loss that preclude implantantion of a standard cemented patellar component. Several options including patellectomy, non resurfacing and osteotomy or grafting of remaining bony shell have been proposed. It is rare in primary knee arthroplasty that the patella has been so eroded that resurfacing is not feasible. Trabecular metall patella may be indicate in the complex revision or even primary knee arthroplasty in which all that remains of the patella is a thin shell of anterior cortical. The short-term results of patellar resurfacing with trabecular metal have demonstrated favorable results

Introduction: We report our experience with use of the SMILES prosthesis in primary knee arthroplasty. Methods: The Stanmore Modular Individualised Lower Extremity System (SMILES prosthesis) has been shown to be effective in complex revision knee surgery. It incorporates a rotating hinge platform knee joint and can overcome the major problems of bone loss and ligamentous laxity. 38 patients (41 knees) who received a primary SMILES knee prosthesis by one of the senior authors between 1990 and 2006 were retrospectively studied. Knee function was assessed pre and post-operatively using the Oxford knee score (0–48 scoring system) and the Knee Society Score. Patients receiving surgery for tumours were excluded. The main indications for primary SMILES were bone loss and ligamentous laxity. Results: The minimum follow-up was 18 months with a mean of 5 years (1–17). The mean age of the patients was 57.7 years (23–86); 15 of the patients were male. The indications for surgery were trauma (12), osteoarthritis with deficient medial collateral ligament (8), polio (7), rheumatoid arthritis (5), epiphyseal dysplasia (4), achondroplasia (2), avascular necrosis (1), osteogenesis imperfecta (1) and ankylosing spondylitis (1). 2 patients died and 5 were lost to follow-up. 2 patients required revision surgery (one for infection and one for re-bushing). Post-operative complications included peroneal nerve palsy (1) and DVT (1). The mean Oxford knee score improved from 9 pre-op to 44 post-op, and the mean knee society score improved from 24 pre-op to 71 post-op. The average range of motion was 57 degrees pre-op and 88 degrees post-op. Conclusion: We conclude that the SMILES prosthesis offers significant improvement in clinician and patient assessed outcome scores in complex primary knee arthroplasty. The cost compares favourably with other designs and its use is well established

Introduction and Aims: To assess the 10-year outcome of knee arthroplasty surgery in a generalist setting, across a single UK health region. Method: The Trent Arthroplasy Audit Group has been collecting prospective data on primary knee replacements since 1990. 4677 primary knee replacements were performed in the period 1990–92. A validated self-administered questionnaire, including a EuroQol health evaluation questionnaire, was mailed to all surviving patients. The mean age at the time of surgery was 70 years. Results: Thirty-nine percent of the patients had died by 10 years. Responses were received from 87% of patients. Eighty-two percent of patients had been satisfied with the result of their knee replacement. Twenty-one percent of patients felt that it was not as good as they had been led to believe before surgery. Forty percent of patients had had problems with their knee in the 10 years since surgery. Twenty-one percent had had some form of surgical intervention. Eighty-two percent of patients were taking medication to alleviate pain in their replaced knee. Eighteen percent complained of constant pain in this knee. When the pain occurred it was described as being severe in 16% and moderate in 40%. Most patients were on prescribed medication, but had not been referred to a surgeon to identify if there was a problem with their implant. The revision rate, for all causes at 10 years was 13%. Conclusion: The results of knee arthroplasty at 10 years are disappointing. Patients’ responses indicate that previously successful knees are becoming painful. At the present time there appears to be inadequate long-term follow-up/re-referral of patients and surgeons have a high threshold for revision surgery. More detailed clinical examination is planned for this group of patients

The Trent Arthroplasty Audit Group (TAAG) is an arthroplasty register set up over ten years ago to record data on all hip and knee arthroplasties performed in the Trent region. This currently serves a population of 5.16 million with an average of 10,000 arthroplasties recorded each year. Patients are sent a postal questionnaire at one year post surgery to record satisfaction with surgery amongst some of its parameters. We analysed the questionnaires returned on patients having undergone primary knee arthroplasties during the years 97/98. Those recording a poor satisfaction score were then analysed to see if any trends emerged and thus achieve our aim of improving overall satisfaction scores within Trent. In 1997/98, 3219 primary knee replacements were perfomed in Trent, of which 241(12%) recorded a poor satisfaction rating. Analysing this group, 30% of patients had no clinically identifiable cause for their dissatisfaction. No correlation between type of implant used could be suggested. In 28% of patients the surgeons were unaware of their patients’ dissatisfaction in clinic. Bilateral arthroplasties had been performed in 25% of the dissatisfied group. Re-evaluating this group 4 years post-op, improved their dissatisfaction to 7%. Our study indicates that a high proportion of patients (12%), undergoing knee replacement surgery record a poor satisfaction score at one year post-op. The respective consultants were unaware of any problem in 30% of cases, despite follow up. This rating improved to 7% without intervention in many cases. We suggest that this may be due to high expectations and appropriate pre-operative counselling needs to be undertaken before such surgery

It is unusual to require the use of a total knee implant with more constraint than a posterior-stabilised post in primary knee arthroplasty. The most common indication is a knee with a severe deformity, usually fixed valgus with an incompetent medial collateral ligament, and an inability to correctly balance the knee in both flexion and extension. The pre-operative deformity is usually greater than 15–20 degrees fixed valgus and may be associated with a severe flexion contracture. This is usually seen in an elderly female patient with advanced osteoarthritis. Those pre-operative diagnoses more likely to require a constrained design include advanced rheumatoid arthritis, true neuropathic joint, and the “Charcot-like” joint due to bone loss or crystalline arthritis. Rarely, patients with periarticular knee Paget's disease of bone may require more constraint following correction of a severe deformity through the knee joint. Beware those patients with a staple or screw at the medial epicondyle or those with severe heterotopic ossification at the medial joint line, as this may signify a serious prior injury to the medial collateral ligament. Finally, there is a possibility of inadvertent division of the medial collateral ligament intra-operatively. Although this situation may be treated with suture repair and bracing, my choice is to switch to more constraint and early unbraced motion. There are over 20 designs of varus-valgus constrained components, with a variety of tibial post designs with specific rotary and angular biomechanics, and many have the option of adding modular stems. Our experience with constrained, non-linked designs has been favorable with both the use of nonmodular and modular stem extensions. Longer-term survival analysis has shown a 96% survival at 10 years with these constrained components. However, the older designs frequently required a lateral retinacular release for proper patella tracking, and there were patella complications (fracture and osteonecrosis) in 16%. With a more modern design, over the past 12 years, the need for a lateral retinacular release and patella complications have been notably decreased. Varus-valgus constrained components have a small but important role in primary total knee arthroplasty for patients with severe deformity or an incompetent medial collateral ligament

The August 2023 Research Roundup³⁶⁰ looks at: Can artificial intelligence improve the readability of patient education materials?; What is the value of radiology input during a multidisciplinary orthopaedic oncology conference?; Periprosthetic joint infection in patients with multiple arthroplasties; Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project - Phase III outcomes; Knot tying in arthroplasty and arthroscopy causes lesions to surgical gloves: a potential risk of infection; Vascular calcification of the ankle in plain radiographs equals diabetes mellitus?

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

Introduction: The emergence of Independent Sector Treatment Centres (ISTCs) in the UK for the provision of elective orthopaedic services began in 2002–3. Within our trust the bulk of elective orthopaedic surgery is performed in an ISTC however there is a small but significant cohort of patients who are deemed not suitable for treatment at the ISTC. Patients with a BMI (body mass index) ≥40 or an ASA (American society of anaesthesiologists) grade of 3 or more are automatically rejected. With increasing levels of obesity and an aging population the size of the reject cohort is going to rise. These patients are then returned to the NHS to be placed on a new (complex elective) waiting list for their surgery. The aim of this study was to assess the early outcomes and complications following primary knee arthroplasty on our high risk patients. Methods: A retrospective review of a consecutive series of 214 primary knee arthroplasties in patients rejected from the ISTC was performed. Data (demographics, ASA grade, BMI, length of stay, complications, range of knee movement and requirement for HDU/ICU) were collected from preoperative assessments, inpatient notes, anaesthetic charts, discharge summaries and follow up clinic letters. All patients were followed up for a minimum of 6 months. Results: 155 (72%) patients were female. 140 (65%) had ASA of 3 or more. 88 (41%) had a BMI of 40 or more. Median length of stay was 8 days (6 to 11 IQR) and did not vary with increasing BMI but increased to 10 days in the ASA 3 and 12 days in the ASA 4 group. There were a total 90 complications in 71 patients. The most common complications were 22 superficial wound infections (10.3%), 11 Pneumonias (5.1%), and 9 symptomatic DVTs (4.2%). There were 16 severe complications (2 Deep infections, 4 PEs, 2 CVAs, 4 acute renal failures and 4 dislocations) in 15 patients. Patients with a BMI < 40 had a total complication rate of 38% (7.9% severe) compared with 26% (5.7% severe) in BMI ≥40 group. Patients with an ASA < 3 had a complication rate of 31% (4.1% severe) vs. 34% (8.6% severe) in patients with an ASA ≥ 3. HDU/ICU beds were required postoperatively for 20 patients (9 planned and 11 unplanned). At six months 72% achieved a knee range of movement ≥ 0 to 90 degrees. Surgeons who performed high volumes of surgery in this difficult group had lower complications then lower volume surgeons. Conclusion: This is one of the largest consecutive groups of high risk patients undergoing primary total knee arthroplasty. Our results show that elevated BMI does not appear to adversely affect complication rates in knee arthroplasty in our series although ASA grades of 3 and 4 are associated with increased length of stay and complication rates. It is also clear that small groups of surgeons operating on these difficult patients may reduce complications

We aim to explore the potential technologies for monitoring and assessment of patients undergoing arthroplasty by examining selected literature focusing on the technology currently available and reflecting on possible future development and application. The reviewed literature indicates a large variety of different hardware and software, widely available and used in a limited manner, to assess patients’ performance. There are extensive opportunities to enhance and integrate the systems which are already in existence to develop patient-specific pathways for rehabilitation.

Cite this article: Bone Joint J 2022;104-B(10):1104–1109.

We sought to determine the incidence of complications and re-operation up to one year following primary total knee replacement in a single health region. The Trent Arthroplasty Audit group collects prospective data on all knee replacements performed within this health region (population 5.2 million). All patients are sent a validated, self-administered questionnaire one year after surgery. The questionnaire addresses patient satisfaction and any complications and re-operations following surgery. We analysed the returned questionnaires of 5352 patients [5896 knees] who had their primary knee arthroplasty between 1998 to 2000. Responses were received from 4169 patients [4592 knees] (response rate 80%). Clinical records were also examined to gain further information. 516 patients reported complications in 546 knees. Complication rate of (12%) and 3.5% had a further operation on the joint within one year. Complications were highest following knee replacement for trauma (36%) followed by osteoarthritis (12%) and lowest for rheumatoid arthritis (8%). We have no knowledge of the complexity of the surgery but 60% of the complications occurred in patients operated on by a Consultant, 29% by a Specialist Registrar and 10% by an Associate Specialist & Staff Grade. On the whole Consultants performing fewer than 10 joint replacements per year registered a higher complication rate (21%) as compared to Consultants performing more than 25 joints per year (12%), but they performed 18% of the arthroplasties. The incidence of complications, as stated by the patient was as follows: Pain 7%, Stiffness 2%, Superficial infection 1%, Swelling 0.7%, Deep infection 0.7%, DVT 0.4%. 1.2% (infection 0.4%: Instability 0.7%: Patellar resurfacing 0.2%), Manipulation (1.3%), Arthroscopy (0.7%), ORlF of Peri-prosthetic fracture (0.06%). 12 % of the patients who had a primary knee replacement in Trent region between 1998 and 2000 considered that they had a complication. Complications rates appear to be higher for surgeons performing less than 10 joint replacements per year. Only 43% of Consultants performed more than 10 knee arthroplasties themselves in any one of these three years. The deep infection rate was 0.4% and one-year post surgery the revision rate, for all causes was 1.2% and the manipulation rate was 1.3%

Aims

The aim of this study was to describe and compare joint-specific and generic health-related quality of life outcomes of the first versus second knee in patients undergoing staged bilateral total knee arthroplasty (BTKA) for osteoarthritis.

Aims

The primary aim was to assess change in health-related quality of life (HRQoL) of patients as they waited from six to 12 months for a total hip (THA) or total or partial knee arthroplasty (KA). Secondary aims were to assess change in joint-specific function, mental health, quality of sleep, number living in a state worse than death (WTD), wellbeing, and patient satisfaction with their healthcare.

Aims

Patient dissatisfaction following primary total knee arthroplasty (TKA) with manual jig-based instruments has been reported to be as high as 30%. Robotic-assisted total knee arthroplasty (RA-TKA) has been increasingly used in an effort to improve patient outcomes, however there is a paucity of literature examining patient satisfaction after RA-TKA. This study aims to identify the incidence of patients who were not satisfied following RA-TKA and to determine factors associated with higher levels of dissatisfaction.

Aims

The primary objective of this registry-based study was to compare patient-reported outcomes of cementless and cemented medial unicompartmental knee arthroplasty (UKA) during the first postoperative year. The secondary objective was to assess one- and three-year implant survival of both fixation techniques.

Aims

The aim of this study was to determine the long-term mortality rate, and to identify factors associated with this, following primary and revision knee arthroplasty (KA).

The statements contained in this document are solely those of the authors and do not necessarily reflect the views or policies of CMS. The authors assume responsibility for the accuracy and completeness of the information contained in this document. Background. The Bundled Payments for Care Improvement (BPCI) initiative was introduced to reduce healthcare costs while maintaining quality. We examined data from a healthcare system comprised of five hospitals that elected to participate in the BPCI Major Joint Replacement of the Lower Extremity Model 2 initiative beginning July 1, 2015. We compared one hospital that did 507 BPCI knee cases to the four other hospitals that did 566 cases. Stratifying the data by hospital volume, we sought to determine if costs decreased during the BPCI period, how the savings were achieved, and if savings resulted in financial rewards for participation. Methods. The Medicare data included the target cost for each episode (based on historical data from 2009–2012 for each hospital that was adjusted quarterly) and actual Part A and Part B spending for 90 days. Using 1,836 primary knee replacements, we analyzed the costs associated with the anchor hospitalization, inpatient rehabilitation, skilled nursing facilities, home health, outpatient physical therapy and readmission to compare the 1,073 knees done during the 16-month BPCI initiative period with the 763 knees done during the 1-year period preceding BPCI participation. Owing to the nonparametric distribution of the cost data, a Mann-Whitney U test was used to compare the higher volume hospital with the four lower volume hospitals. Results. Compared to the preceding year, the mean episode of care cost during BPCI participation decreased by 8.5% (from $20,853 to $19,087, p=0.24) at the higher volume hospital while remaining virtually unchanged (going from $20,383 to $20,380, p=0.10) at the lower volume hospitals. During the BPCI period, the mean Medicare 90-day target cost was $18,307 at the higher volume hospital and $22,287 at the lower volume hospitals (p<0.001). At the higher volume hospital, the major components of the savings included $367,290 from reduced readmission rates (5.7% versus 8.7%, p=0.11), $207,608 primarily due to a reduction in the length of stay at skilled nursing facilities (mean 15 days versus 25 days, p=0.005), and $130,894 associated with a decreased percentage of patients using inpatient rehabilitation (3.2% versus 4.9%, p=0.22). Although offset by other cost increases, the largest component of the savings at the lower volume hospitals was $262,548 due to a decrease in the percentage of patients (2.3% versus 4.8%, p=0.04) using inpatient rehabilitation. Despite its savings, the mean reconciliation penalty was $851 per case at the higher volume hospital while the lower volume hospitals received a mean reward of $2,165 per case. Conclusion. Based on the reduction in costs and decreased readmission rates, the BPCI initiative is achieving its objectives. Despite an 8.5% decrease in costs, the $18,307 target based on historical data resulted in an $851 penalty per case at the higher volume hospital. In contrast, as a result of a $3,980 higher target, the lower volume hospitals were rewarded even though they did not achieve cost savings. As structured, there is no incentive for centers with historically low costs to participate in BPCI