Aims. In-hospital length of stay (LOS) and discharge dispositions following arthroplasty could act as surrogate measures for improvement in patient pathways, and have major cost saving implications for healthcare providers. With the ever-growing adoption of robotic technology in arthroplasty, it is imperative to evaluate its impact on LOS. The objectives of this study were to compare LOS and discharge dispositions following robotic arm-assisted total knee arthroplasty (RO TKA) and unicompartmental arthroplasty (RO UKA) versus conventional technique (CO TKA and UKA). Methods. This large-scale, single-institution study included patients of any age undergoing primary TKA (n = 1,375) or UKA (n = 337) for any cause between May 2019 and January 2023. Data extracted included patient demographics, LOS, need for post anaesthesia care unit (PACU) admission, anaesthesia type, readmission within 30 days, and discharge dispositions. Univariate and multivariate logistic regression models were also employed to identify factors and patient characteristics related to delayed discharge. Results. The median LOS in the RO TKA group was 76 hours (interquartile range (IQR) 54 to 104) versus 82.5 (IQR 58 to 127) in the CO TKA group (p < 0.001) and 54 hours (IQR 34 to 77) in the RO UKA versus 58 (IQR 35 to 81) in the CO UKA (p = 0.031). Discharge dispositions were comparable between the two groups. A higher percentage of patients undergoing CO TKA required PACU admission (8% vs 5.2%; p = 0.040). Conclusion. Our study showed that robotic arm assistance was associated with a shorter LOS in patients undergoing primary UKA and TKA, and no difference in the discharge destinations. Our results suggest that robotic arm assistance could be advantageous in partly addressing the upsurge of knee arthroplasty procedures and the concomitant healthcare burden; however, this needs to be corroborated by long-term cost-effectiveness analyses and data from randomized controlled studies. Cite this article: Bone Jt Open 2023;4(10):791–800

Introduction. Postoperative pain is a concern for patients undergoing Total Knee Arthroplasty (TKA) and plays an important role in opioid consumption, length of stay, and postoperative function. The purpose of this study was to compare outcomes in patients who underwent primary TKA comparing femoral and sciatic (F+S) combination motor nerve block versus an adductor canal and the interspace between the popliteal artery and the capsule of the posterior knee (ACB+IPACK) combination sensory nerve block. Methods. 100 consecutive primary TKA cases performed by a single surgeon using the same surgical approach and implant design were reviewed. The first 50 patients received F+S nerve blocks and the second 50 received ACB+IPACK blocks preoperatively. Both groups also received total intravenous anesthesia (TIVA). Differences in opioid requirements, length of stay (LOS), distance walked, Western Ontario & McMasters University Osteoarthritis Index (WOMAC), Knee Society (KSS) function scores, Visual Analog Scores (VAS) for pain at rest and with activity, and postoperative complications were analyzed. There were no differences in the groups with respect to age, sex or BMI. Results. 62% of patients were discharged on postoperative day #1 in the ACB+IPACK group compared to 14% in the F+S group (p<.0001). The ACB+IPACK patients had a shorter LOS (average 1.48 days versus 2.02 days, p<0.0001), ambulated further on postop day #0 (average 21.4 feet versus 5.3 feet, p<0.0001), required less narcotics the day after surgery (average 15.7 versus 24.0 morphine equivalents p<0.0001) and at 2 weeks postoperative (average 6.2 versus 9.3 morphine equivalents, p=0.025), and required less manipulations under anesthesia (1 versus 5, p=0.204). WOMAC, KSS, and VAS scores were not significantly different. Discussion. The use of combination adductor canal and IPACK sensory blocks demonstrated improved early ambulation with decreased opioid use, length of stay, and postoperative manipulations. This study suggests that the use of combination sensory adductor canal and IPACK nerve blocks are superior to motor nerve blocks in patients undergoing primary TKA

Introduction. Social determinants of health (SDOH) may contribute markedly to the total cost of care (COC) for patients undergoing elective total knee arthroplasty (TKA). This study investigated the association between demographics, health status, and SDOH on lengths of stay (LOS) and 30-day COC. Methods. Patients who underwent TKA between January 2018 and December 2019 were identified. Those who had complete SDOH data were utilized, leaving 234 patients. Data elements were drawn from the Chesapeake Regional Information System, the Center for Disease Control social vulnerability index (SVI), the Food Access Research Atlas (FARA). The SVI identifies areas vulnerable to catastrophic events, with 4 themed scores including: (1) socioeconomic status; (2) household composition and disability; (3) minority status and language; and (4) housing and transportation. Food deserts were defined as neighborhoods located 1 or 10 miles from a grocery store in urban and rural areas, respectively. Multiple regression analyses were performed to determine an association with LOS and cost, after controlling for demographics. Results. Increased 30-day COC associated with SVI theme 3, (3.074 days; p=0.001) and patients who lived in a food desert ($53,205; p=0.001), as well as those who had anemia ($16,112; P = 0.038), chronic obstructive pulmonary disease ($32,570, P = 0.001), congestive heart failure ($30,927, P = 0.003), and dementia ($33,456, P = 0.008). Longer hospital lengths of stay were associated with SVI theme 3. In addition, patients who had anemia and congestive heart failure were at risk for longer hospital lengths of stay (P < 0.001, P = 0.001, respectively). Conclusion. Higher SVI theme 3 scores and living in food deserts were risk factors for increased LOS and costs, respectively. Identifying social factors including a patient's transportation options, living situation and access to healthy foods may prove to be both prognostic of outcomes and an opportunity for intervention

Introduction. We designed this study to compare 30-day complications and length of hospital stay between patients undergoing total knee arthroplasty (TKA) with general anesthesia, to those undergoing TKA with spinal, epidural anesthesia, or Monitored Anesthesia Care (MAC, a combination of local anesthesia with sedation and analgesia provided by an anesthesiologist) with or without regional nerve blocks. Methods. We identified patients ≥18 years undergoing TKA between the years of 2006 and 2017 from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). We collected patient demographics, anesthesia type, 30-day complications, length of operation and hospital stay from the database. We used multivariable regression to compare complications and length of stay (LOS) between anesthesia types, while adjusting for relevant covariables. Results. We identified 265,325 TKA patients. Of these, 91 (0.03%) underwent epidural anesthesia with a nerve block, while 1,855 (0.70%) underwent epidural anesthesia with no block, 12,800 (4.82%) underwent MAC with a block, 25,643 (9.66%) underwent MAC with no block, 13,575 (5.12%) underwent spinal anesthesia with a block, 80,803 (30.45%) underwent spinal anesthesia with no block, and 130,558 (49.21%) underwent general anesthesia. The rate of complications was not associated with the presence of a block, while the unadjusted LOS was significantly lower with the use of a block in patients treated with spinal anesthesia (2.54±2.07 vs. 2.84±2.25), epidural anesthesia (2.87±1.81 vs. 3.88± 4.67), and MAC (2.51±2.14 vs. 2.68±2.11), p<0.0001. The unadjusted rate of major complications was significantly lower in patients who underwent spinal anesthesia (2.10%), and MAC (1.91%) compared to general anesthesia (2.31%), p<0.0001. Similarly, the unadjusted rate of minor complications was significantly lower for patients treated with spinal anesthesia(1.86%) and MAC (1.78%) compared to general anesthesia (2.11%), p<0.0001. The unadjusted LOS was significantly longer in patients treated with epidural (3.83±4.58), compared to general (2.94±3.64) anesthesia, p<0.0001. In contrast, the unadjusted LOS was significantly lower for patients treated with spinal anesthesia (2.80±2.23), and MAC (2.62±2.12) compared to general anesthesia, p<0.0001. Following covariable adjustment, spinal anesthesia and MAC were associated with a 0.93 (0.87–0.98), and 0.84 (0.78–0.91), odds of major complications compared to general anesthesia. Similarly, spinal anesthesia and MAC were associated with a 0.92 (0.87–0.98) and 0.89 (0.82–0.97) odds of minor complications compared to general anesthesia. Following covariable adjustment, epidural anesthesia increased the LOS by 0.25 (0.27–0.28) days compared to general, while spinal anesthesia and MAC decreased the LOS by 0.04 (95%CI 0.05–0.04), and 0.10 (0.11–0.09) days, compared to general. In patients treated with spinal anesthesia, epidural anesthesia, and MAC, the use of a block was independently associated with a decreased LOS by 0.10 (0.12–0.90), 0.24 (0.39–0.09), and 0.07 (0.08–0.05). Conclusion. Patients who undergo TKA with spinal anesthetic, and MAC appear to have superior outcomes compared to those who undergo TKA with general anesthesia. In addition, the use of a regional nerve block appears to be independently associated with a shorter LOS in patients who undergo TKA with neuraxial (spinal and epidural) anesthetic, and MAC. For figures, tables, or references, please contact authors directly

Abstract. Background. There is a trend towards minimising length of stay (LOS) after total knee arthroplasty (TKA), as longer LOS is associated with poorer outcomes and higher costs. Patient factors known to influence LOS after TKA include age and ASA grade. Evidence regarding body mass index (BMI) in particular is conflicting. Some studies find that increased BMI predicts greater LOS, while others find no such relationship. Previous studies have generally not examined socioeconomic status, which may be a confounder. They have generally been conducted outside the UK, and prior to the Covid-19 pandemic. Methods. We conducted a retrospective cohort study of 1031 primary TKAs performed 01-04-2021 to 31-12-2021, after resumption of elective surgery in our centre. A multivariate regression analysis was performed using a Poisson model over pre-operative variables (BMI, age, gender, ASA grade, index of multiple deprivation, and living arrangement) and peri-operative variables (AM/PM operation, operation side, duration, and day of the week). Results. Mean LOS was 2.6 days. BMI had no effect on LOS (p > 0.05). Longer LOS was experienced by patients of greater age (p < 0.001), increased ASA grade (p < 0.001), living alone (p < 0.01), PM start time (p < 0.001), and longer operation duration (p < 0.01). Male patients had shorter LOS (p < 0.001). Index of multiple deprivation had no effect (p > 0.05). Conclusion. BMI had no effect on LOS after TKA. Being female and living alone are significant risk factors which should be taken in to account in pre-operative planning

Our aim in this audit was to determine whether intensive rehabilitation post-operatively influenced length of stay and readmission rates for patients undergoing primary total knee arthroplasty. In September 2007, a dedicated weekend physiotherapy service was set up in our Trust for patients following joint arthroplasty at a cost of £30,000 per annum. A prospective audit was conducted over two six-month periods, before and after the introduction of this service, including 202 and 240 patients respectively. Patient demographics including ASA grade and strict inclusion and exclusion criteria were used. The effect of anaesthetic type on post-operative pain control was also reviewed. Chi-squared and Mann-Whitney tests were used to analyse non-parametric data. In the second cohort, with intensive rehabilitation, a statistically significantly higher number of patients were discharged within seven days of admission (64% vs 36%, p<0.01). This was despite there being a significantly higher number of patients with high ASA grades 3-4 in this cohort (37% vs 27%, p<0.05). The median length of stay in the second cohort was seven days compared to eight in the first cohort. There was a slight increase in rate of readmission within the second cohort but this was not statistically significant. We found that the addition of a femoral nerve block significantly reduced post-operative pain. We concluded that an annual financial saving to the Trust of approximately £118,000 could be made by the addition of an additional dedicated physiotherapist in our unit. Patients can be safely discharged sooner with intensive rehabilitation and may benefit in the longer term by improved knee function

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

Abstract. Introduction. Spinal local anaesthesia and opioids have long been used as peri-operative analgesia for patients undergoing arthroplasty procedures. However, intrathecal opioids are associated with numerous complications. ERAS. ®. society guidelines for elective knee replacement (2019) strongly discourage the use of spinal opioids. This study aims to report the impact of low-dose spinal and local infiltrative analgesia on patients undergoing elective knee replacement. Methodology. Retrospective cohort study of patients undergoing knee replacement under the ERAS protocol over 2 years, at a district general hospital under the care of a single surgeon. Results. A total of 80 knee replacements were included in the study (M38:F42, mean age=72.7, mean BMI=31, ASA: 1=8, 2=54, 3=18). 91% received neuroaxial anaesthesia, 89% without intrathecal opioids. Local infiltrative analgesia was used in 99% of patients. The mean length of stay was significantly shorter (2 days), when compared to patients undergoing elective knee replacements without adherence to ERAS. ®. guidance (3.8 days), P<0.001. The average maximum pain score in PACU was 0.8 (0=no pain, 10=maximum pain). All patients were mobilised within 24 hours of surgery. No patients were readmitted within 30 days. 2 patients returned to theatre (retained surgical clip and MUA for stiffness). Conclusions. The implementation of ERAS. ®. guidelines has demonstrated significantly reduced admission days following elective knee arthroplasty. Combined with low complication rates, the reduction in admission days may result in increased hospital bed availability. This has the potential to positively impact elective arthroplasty waiting lists. Further research is underway to evaluate patient-reported outcome measures in this group

Background. The evaluation and management of outcomes risk has become an essential element of a modern total joint replacement program. Our multidisciplinary team designed an evidence-based tool to address modifiable risk factors for adverse outcomes after primary hip and knee arthroplasty surgery. Methods. Our protocols were designed to identify, intervene, and mitigate risk through evidence-based patient optimization. Nurse navigators screened patients preoperatively, identified and treated risk factors, and followed patients for 90 days postoperatively. We compared patients participating in our optimization program (N=104) to both a historical cohort (N=193) and a contemporary cohort (N=166). Results. Risk factor identification and optimization resulted in lower hospital length of stay and post-operative emergency department visits. Patients in the optimization cohort had a statistically significant decrease in mean LOS as compared to both the historical cohort (2.55 vs 1.81 days, P<0.001) and contemporary cohort (2.56 vs 1.81 days, p<0.001). Patients in the optimization cohort had a statistically significant decrease in 30- and 90-day ED visits compared to the historical cohort (P. 30-day. =0.042, P. 90-day. =0.003). When compared with the contemporary cohort, the optimization cohort had a statistically significant decrease in 90-day ED visits (21.08% vs. 10.58%, P=0.025). The optimization cohort had a statistically significant increase in the percentage of patients discharged home. We noted nonsignificant reductions in readmission rate, transfusion rate, and surgical site infections. Conclusion. Optimization of patients prior to elective primary THA and TKA reduced average LOS, ED visits, and drove tele-rehabilitation use. Our results add to the limited body of literature supporting this patient-centered approach

Aim. The aim of this study was to determine the factors which were responsible for differences between patients achieving the Trust target of discharge on post-operative day 5 after a primary total knee replacement and those not achieving it, in the cohort of over 75 year olds. Methods and Results. Of all the patients undergoing a TKR at Addenbrooke's Hospital in 2008, those over 75 were identified (n=103). From the literature pre-, intra- and post-operative factors that had previously been shown to affect length of stay were identified. Patient notes were examined for details on each of these and the patients divided into 2 groups according to whether their discharge was achieved by day 5 or not. Data from 74 operations was available at the time of submission of this abstract. Pearson's Chi-squared test, student's independent t-test or the Mann-Whitney U test were performed on the data depending on the nature of the variable analysed. The following factors were found to be significantly different between the 2 groups at the 95% confidence level: pre-operative use of a walking aid (p=0.033), pre-operative Hb (p=0.003), post-operative Hb (p=0.001), post-operative requirement of a blood transfusion, post-operative complication (p<0.001), post-operative day on which active knee flexion to 90° was achieved (p=0.003). In addition the following factors were found to be significant at the 90% confidence level: age (p=0.082), comorbidity (p=0.086), marital status (p=0.095) and mobilisation by post-operative day 2 (p=0.082). Conclusion. Pre-operative use of any walking aid, peri-operative haemoglobin concentration and post-operative complications (including the need for a blood transfusion) seem to be the significant factors associated with a prolonged stay in hospital in the over 75 year olds. A few other factors are bordering on significance and they warrant further investigation in a larger patient cohort

In Scotland, the number of primary total knee replacements performed annually has been increasing steadily. The price of the implant is fixed but the length of hospital stay is variable. We prospectively investigated all patients who underwent primary unilateral total knee replacement in the Scottish region of Fife, between December 1994 and February 2007 and assessed their recorded pre-operative details. The data were analysed using univariate and multiple linear regression statistical analysis. Data on the length of stay were available from a total of 2106 unilateral total knee replacements. The median length of hospital stay was eight days. The significant pre-operative risk factors for an increased length of stay were the year of admission, details of the consultant looking after the patient, the stair score, the walking-aid score and age. Awareness of the pre-operative factors which increase the length of hospital stay may provide the opportunity to influence them favourably and to reduce the time in hospital and the associated costs of unilateral total knee replacement

PURPOSE OF STUDY. We investigated the effect of weekend knee arthroplasty surgery on length of inpatient stay. METHODS. 341 consecutive patients undergoing primary total knee replacement were retrospectively identified. Of these 62 underwent surgery during the weekend. Length of inpatient stay, age, sex, pre-operative haemoglobin, ASA rating, and day of surgery were recorded. Multiple regression analysis was used to determine the effect of these preoperative factors on length of post-operative inpatient stay. RESULTS. The mean length of stay following primary knee replacement was 5.9 days, with a median 4 days (2-31). Multivariate analysis confirmed that age at operation, sex, pre-operative haemoglobin and ASA were predictive of length of stay following knee arthroplasty. The day of the operation was not predictive of length of post operative stay. DISCUSSION. The results from this study suggest age, sex, ASA and preoperative haemoglobin are predictive of inpatient hospital stay. This is consistent with previous published data. Day of surgery was not predictive of length of stay. Our results suggest that weekend knee arthroplasty surgery does not result in an increased length of inpatient stay

Aims. Robotic-assisted total knee arthroplasty (RA-TKA) has been introduced to provide accurate bone cuts and help achieve the target knee alignment, along with symmetric gap balancing. The purpose of this study was to determine if any early clinical benefits could be realized following TKA using robotic-assisted technology. Methods. In all, 140 consecutive patients undergoing RA-TKA and 127 consecutive patients undergoing conventional TKA with minimum six-week follow-up were reviewed. Differences in visual analogue scores (VAS) for pain at rest and with activity, postoperative opiate usage, and length of stay (LOS) between the RA-TKA and conventional TKA groups were compared. Results. Patients undergoing RA-TKA had lower average VAS pain scores at rest (p = 0.001) and with activity (p = 0.03) at two weeks following the index procedure. At the six-week interval, the RA-TKA group had lower VAS pain scores with rest (p = 0.03) and with activity (p = 0.02), and required 3.2 mg less morphine equivalents per day relative to the conventional group (p < 0.001). At six weeks, a significantly greater number of patients in the RA-TKA group were free of opioid use compared to the conventional TKA group; 70.7% vs 57.0% (p = 0.02). Patients in the RA-TKA group had a shorter LOS; 1.9 days versus 2.3 days (p < 0.001), and also had a greater percentage of patient discharged on postoperative day one; 41.3% vs 20.5% (p < 0.001). Conclusion. Patients undergoing RA-TKA had lower pain levels at both rest and with activity, required less opioid medication, and had a shorter LOS

Early and accurate prediction of hospital length-of-stay (LOS) in patients undergoing knee replacement is important for economic and operational reasons. Few studies have systematically developed a multivariable model to predict LOS. We performed a retrospective cohort study of 1609 patients aged ≥ 50 years who underwent elective, primary total or unicompartmental knee replacements. Pre-operative candidate predictors included patient demographics, knee function, self-reported measures, surgical factors and discharge plans. In order to develop the model, multivariable regression with bootstrap internal validation was used. The median LOS for the sample was four days (interquartile range 4 to 5). Statistically significant predictors of longer stay included older age, greater number of comorbidities, less knee flexion range of movement, frequent feelings of being down and depressed, greater walking aid support required, total (versus unicompartmental) knee replacement, bilateral surgery, low-volume surgeon, absence of carer at home, and expectation to receive step-down care. For ease of use, these ten variables were used to construct a nomogram-based prediction model which showed adequate predictive accuracy (optimism-corrected R² = 0.32) and calibration. If externally validated, a prediction model using easily and routinely obtained pre-operative measures may be used to predict absolute LOS in patients following knee replacement and help to better manage these patients.

Cite this article: Bone Joint J 2013;95-B:1490–6.

Aims. The aim of this prospective multicentre study was to describe trends in length of stay and early complications and readmissions following unicompartmental knee arthroplasty (UKA) performed at eight different centres in Denmark using a fast-track protocol and to compare the length of stay between centres with high and low utilization of UKA. Methods. We included data from eight dedicated fast-track centres, all reporting UKAs to the same database, between 2010 and 2018. Complete ( > 99%) data on length of stay, 90-day readmission, and mortality were obtained during the study period. Specific reasons for a length of stay of > two days, length of stay > four days, and 30- and 90-day readmission were recorded. The use of UKA in the different centres was dichotomized into ≥ 20% versus < 20% of arthroplasties which were undertaken being UKAs, and ≥ 52 UKAs versus < 52 UKAs being undertaken annually. Results. A total of 3,927 procedures were included. Length of stay (mean 1.1 days (SD 1.1), median 1 (IQR 0 to 1)) was unchanged during the study period. The proportion of procedures with a length of stay > two days was also largely unchanged during this time. The percentage of patients discharged on the day of surgery varied greatly between centres (0% to 50% (0 to 481)), with centres with high UKA utilization (both usage and volume) having a larger proportion of same-day discharges. The 30- and 90-day readmissions were 166 (4.2%) and 272 (6.9%), respectively; the 90-day mortality was 0.08% (n = 3). Conclusion. Our findings suggest general underutilization of the potential for quicker recovery following UKA in a fast-track setup. Cite this article: Bone Joint J 2020;102-B(9):1167–1175

Abstract. Introduction. It is common practice for all patients to have postoperative bloods tests after total knee arthroplasty (TKA). However there have been significant improvement in perioperative care with arthroplasty surgery. As healthcare systems and providers strive towards a more efficient service we must re-consider whether such an intervention is necessary for all patients. Methodology. This retrospective study included all patients who underwent a primary unilateral TKA at a single tertiary arthroplasty centre during a 1 year period. Electronic medical records of 776 patients were reviewed for patient demographics, length of stay and American Society of Anaesthesiologists grade. Blood tests were examined to investigate the incidence of post operative anaemia requiring transfusion, electrolyte abnormalities that required treatment and the incidence of acute kidney injury. Results. Average length of stay in hospital was 4.3 days. Pre-operative (R=-0.22) & post-operative haemoglobin (R=0.2) levels were both negatively correlated with length of stay (p<0.01). There was 1 patient that required a blood transfusion post operatively due to symptomatic anaemia. This patient underwent a complex primary TKA. Significant abnormal post-operative electrolyte levels were found in 100 (12.9%) of patients. 87 of these patients either had abnormal electrolyte levels pre-operatively or were taking a medication that causes the electrolyte abnormality. Medical treatment for abnormal electrolyte levels was required in 32 (4.1%) of all patients. The incidence of acute kidney injury was 4.4%. Conclusion. Routine blood tests after primary total knee arthroplasty is unnecessary for most patients. Blood tests should only be performed in those with identifiable risk factors

Aims. Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up. Methods. This prospective study included 16 patients undergoing robotic arm-assisted revision of UKA to TKA versus 35 matched patients receiving robotic arm-assisted primary TKA. In all study patients, the following data were recorded: operating time, polyethylene liner size, change in haemoglobin concentration (g/dl), length of inpatient stay, postoperative complications, and hip-knee-ankle (HKA) alignment. All procedures were performed using the principles of functional alignment. At most recent follow-up, range of motion (ROM), Forgotten Joint Score (FJS), and Oxford Knee Score (OKS) were collected. Mean follow-up time was 21 months (6 to 36). Results. There were no differences between the two treatment groups with regard to mean change in haemoglobin concentration (p = 0.477), length of stay (LOS, p = 0.172), mean polyethylene thickness (p = 0.065), or postoperative complication rates (p = 0.295). At the most recent follow-up, the primary robotic arm-assisted TKA group had a statistically significantly improved OKS compared with the revision UKA to TKA group (44.6 (SD 2.7) vs 42.3 (SD 2.5); p = 0.004) but there was no difference in the overall ROM (p = 0.056) or FJS between the two treatment groups (86.1 (SD 9.6) vs 84.1 (4.9); p = 0.439). Conclusion. Robotic arm-assisted revision of UKA to TKA was associated with comparable intraoperative blood loss, early postoperative rehabilitation, functional outcomes, and complications to primary robotic TKA at short-term follow-up. Robotic arm-assisted surgery offers a safe and reproducible technique for revising failed UKA to TKA. Cite this article: Bone Joint J 2024;106-B(7):680–687

Abstract. Introduction. In patients with bilateral unicompartmental knee osteoarthritis, simultaneous bilateral surgery is cost effective, with both patient-specific and wider socioeconomic benefits. There are concerns however regarding higher complication rates with bilateral knee surgery. This study compares simultaneous bilateral unicompartmental knee arthroplasty (UKA), to single side UKA in terms of complications and outcomes. Methodology. This is a retrospective case-control study of single side medial UKA patients (controls) and simultaneous bilateral medial UKA patients (cases). All patients underwent surgery between 2018 and 2022 by a single surgeon. The two cohorts were compared for perioperative blood loss (PBL), length of stay (LOS), complications (infections, blood clots, wound problems), Oxford Knee Score improvement (OKS) and revision surgery, with a follow-up period of up to 5 years. Results. 64 patients were followed up comprising 55 controls and 9 cases. Average length of stay for controls was 1.55 days and 2.22 days for cases (p=0.03). Average haemoglobin drop was 7.5g/l in controls and 12.8g/l in cases (p=0.04). The OKS improvement was comparable in both groups (p=0.95) with no complications and no revision surgery in either group. Conclusion. The statistically significant differences in PBL and LOS were not clinically relevant. There were no blood transfusions and postoperative haemoglobin was within normal range in more than 60% of cases. Simultaneous bilateral unicompartmental knee arthroplasty is a financially favourable and safe option for patients with bilateral knee medial unicompartmental osteoarthritis

Aims. The primary aim of the study was to perform an analysis to identify the cost per quality-adjusted life-year (QALY) of robot-assisted unicompartmental knee arthroplasty (rUKA) relative to manual total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) for patients with isolated medial compartment osteoarthritis (OA) of the knee. Secondary aims were to assess how case volume and length of hospital stay influenced the relative cost per QALY. Patients and Methods. A Markov decision analysis was performed, using known parameters for costs, outcomes, implant survival, and mortality, to assess the cost-effectiveness of rUKA relative to manual TKA and UKA for patients with isolated medial compartment OA of the knee with a mean age of 65 years. The influence of case volume and shorter hospital stay were assessed. Results. Using a model with an annual case volume of 100 patients, the cost per QALY of rUKA was £1395 and £1170 relative to TKA and UKA, respectively. The cost per QALY was influenced by case volume: a low-volume centre performing ten cases per year would achieve a cost per QALY of £7170 and £8604 relative to TKA and UKA. For a high-volume centre performing 200 rUKAs per year with a mean two-day length of stay, the cost per QALY would be £648; if performed as day-cases, the cost would be reduced to £364 relative to TKA. For a high-volume centre performing 200 rUKAs per year with a shorter length of stay of one day relative to manual UKA, the cost per QALY would be £574. Conclusion . rUKA is a cost-effective alternative to manual TKA and UKA for patients with isolated medial compartment OA of the knee. The cost per QALY of rUKA decreased with reducing length of hospital stay and with increasing case volume, compared with TKA and UKA. Cite this article: Bone Joint J 2019;101-B:1063–1070

Aims. The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources. Methods. Day-case TKAs, defined as patients discharged on the same calendar day as surgery, were retrospectively reviewed with a minimum follow-up of six months. Analysis of hospital and primary care records was performed to determine readmission and reattendance rates. Telephone interviews were conducted to determine patient satisfaction. Results. Since 2016, 301/7350 TKAs (4.1%) in 290 patients at our institution were discharged on the day of surgery. Mean follow-up was 31.4 months (6.2 to 70.0). In all, 28 patients (9.3%) attended the emergency department or other acute care settings within 90 days of surgery, most often with wound concerns or leg swelling; six patients (2.0%) were readmitted. No patients underwent a subsequent revision procedure, and there were no periprosthetic infections. Two patients (0.7%) underwent secondary patella resurfacing, and one patient underwent arthroscopic arthrolysis after previous manipulation under anaesthetic (MUA). Three patients (1.0%) underwent MUA alone. Primary care consultation records, available for 206 patients, showed 16 patients (7.8%) contacted their general practitioner within two weeks postoperatively; two (1.0%) were referred to secondary care. Overall, 115/121 patients (95%) telephoned stated they would have day-case TKA again. Conclusion. Day-case TKA can be safely delivered in the NHS with no additional resources. We found low incidence of contact with primary and secondary care in the postoperative period, and high patient satisfaction. Cite this article: Bone Jt Open 2023;4(8):621–627