Total knee replacement (TKA) is one of the most successful procedures in orthopaedic surgery. Although originally limited to more elderly and less active individuals, the inclusion criteria for TKA have changed, with ever younger, more active and heavier patients receiving TKA. This broadening of indications coincided with the widespread adoption of modular cemented and cementless TKA systems in the 1980's, and soon thereafter wear debris related osteolysis and associated prosthetic loosening became major modes of failure for TKA implants of all designs. Initially, tibial components were cemented all polyethylene monoblock constructs. Subsequent long-term follow-up studies of some of these implant designs have demonstrated excellent durability in survivorship studies out to twenty years. While aseptic loosening of these all polyethylene tibial components was a leading cause of failure in these implants, major polyethylene wear-related osteolysis around well-fixed implants was rarely (if ever) observed. Cemented metal-backed nonmodular tibial components were first introduced to allow for improved tibial load distribution and protection of the underlying (often osteoporotic) bone. Eventually, modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80s mainly to facilitate screw fixation for cementless implants. These designs also provided intraoperative versatility by allowing interchange of various polyethylene thicknesses, and also aided the addition of stems and wedges. Modular vs. All Polyethylene Tibial Components in Primary TKA: Kremers et al. reviewed 10,601 adult (>18 years) patients with 14,524 condylar type primary TKA procedures performed at our institution between 1/1/1988 and 12/31/2005 and examined factors effecting outcome. The mean age was 68.7 years and 55% were female. Over an average 9 years follow-up, a total of 865 revisions, including 252 tibia revisions were performed, corresponding to overall survival of 89% (Confidence intervals (CI): 88%, 90%) at 15 years. In comparison to metal modular designs, risk of tibial revision was significantly lower with all polyethylene tibias (HR 0.3, 95% CI: 0.2, 0.5). With any revision as the endpoint, there were no significant differences across the 18 designs examined. Similarly, there were no significant differences across the 18 designs when we considered revisions for aseptic loosening, wear, osteolysis. Among patient characteristics, male gender, younger age, higher BMI were all significantly associated with higher risk of revisions (p<0.008). In a more recent review from our institution of over 11, 600 primary TKA procedures, Houdek et al. again showed that all polyethylene tibial components had superior survivorship vs. metal backed designs, with a lower risk of revision for loosening, osteolysis or component fracture. Furthermore, results for all polyethylene designs were better for all BMI subgroups except for those <25 BMI where there was no difference. All polyethylene results were also better for all age groups except for those under age <55 where there again was no difference. Finally, in a recently published meta-analysis of 28 articles containing data on 95,847 primary TKA procedures, all polyethylene tibial components were associated with a lower risk of revision and adverse outcomes. The available current data support the use of all polyethylene tibial designs in TKA in all patients regardless of age and BMI. In all patients, (not just older individuals) use of an all polyethylene tibial component is an attractive and more cost effective alternative, and is associated with the better survivorship and lower risk of revision than seen with modular metal backed tibial components

Management of the pathologic long-head biceps tendon remains controversial. Biceps tenotomy is a simple intervention but may result in visible deformity and subjective cramping. Comparatively, biceps tenodesis is technically challenging, and has increased operative times, and a more prolonged recovery. The purpose of this study was to determine the incidence of popeye deformity following biceps tenotomy versus tenodesis, identify predictors for developing a deformity, and compare subjective and objective outcomes between those that have one and those that do not. Data for this study were collected as part of a randomized clinical trial comparing tenodesis versus tenotomy in the treatment of lesions of the long head of biceps tendon. Patients 18 years of age or older with an arthroscopy confirmed biceps lesion were randomized to one of these two techniques. The primary outcome measure for this sub-study was the rate of a popeye deformity at 24-months post-operative as determined by an evaluator blinded to group allocation. Secondary outcomes were patient reported presence/absence of a popeye deformity, satisfaction with the appearance of their arm, as well as pain and cramping on a VAS. Isometric elbow flexion and supination strength were also measured. Interrater reliability (Cohen's kappa) was calculated between patient and evaluator on the presence of a deformity, and logistic regression was used to identify predictors of its occurrence. Linear regression was performed to identify if age, gender, or BMI were predictive of satisfaction in appearance if a deformity was present. Fifty-six participants were randomly assigned to each group of which 42 in the tenodesis group and 45 in the tenotomy group completed a 24-month follow-up. The incidence of popeye deformity was 9.5% (4/42) in the tenodesis group and 33% (15/45) in the tenotomy group (18 male, 1 female) with a relative risk of 3.5 (p=0.016). There was strong interrater agreement between evaluator and patient perceived deformity (kappa=0.636; p<0.001). Gender tended towards being a significant predictor of having a popeye with males having 6.6 greater odds (p=0.090). BMI also tended towards significance with lower BMI predictive of popeye deformity (OR 1.21; p=0.051). Age was not predictive (p=0.191). Mean (SD) satisfaction score regarding the appearance of their popeye deformity was 7.3 (2.6). Age was a significant predictor, with lower age associated with decreased satisfaction (F=14.951, adjusted r2=0.582, p=0.004), but there was no association with gender (p=0.083) or BMI (p=0.949). There were no differences in pain, cramping, or strength between those who had a popeye deformity and those who did not. The risk of developing a popeye deformity was 3.5 times higher after tenotomy compared to tenodesis. Male gender and lower BMI tended towards being predictive of having a deformity; however, those with a high BMI may have had popeye deformities that were not as visually apparent to an examiner as those with a lower BMI. Younger patients were significantly less satisfied with a deformity despite no difference in functional outcomes at 24 months. Thus, biceps tenodesis may be favored in younger patients with low BMI to mitigate the risk of an unsatisfactory popeye deformity

Introduction. High BMI has been classically regarded as a contraindication for unicompartmental knee arthroplasty (UKA) as it can potentially lead to poor clinical outcomes and a higher risk of failure. In recent years, UKA has increased in popularity and, as a result, patient selection criteria are beginning to broaden. However, UKA performed manually continues to be technically challenging and surgical technique errors may result in suboptimal implant positioning. UKA performed with robotic assistance has been shown to improve component positioning, overall limb alignment, and ligament balancing, resulting in overall improved clinical outcomes. The purpose of this study is to examine the effect of high BMI in patients receiving UKA with robotic assistance. Methods. 1007 patients (1135 knees) were identified in an initial and consecutive multi-surgeon multi-center series receiving robotically assisted medial UKA, with a fixed bearing metal backed onlay tibial component. As part of an IRB approved study, every patient in the series was contacted at a minimum two year (±2 months) follow up and asked a series of questions to determine implant survivorship and satisfaction. 160 patients were lost to follow up, 35 patients declined to participate, and 15 patients were deceased. 797 patients (909 knees) at a minimum two year follow up enrolled in the study for an enrollment rate of 80%. 45% of the patients were female. The average age at time of surgery was 69.0 ± 9.5 (range: 39–93). BMI data was available for 887 knees; the average BMI at time of surgery was 29.4 ± 4.9. Patients were stratified in to five categories based on their BMI: normal (< 25; 16%), overweight (25–30; 46%), obese class I (30–35; 25%), obese class II (35–40; 11%) and obese class III (>40; 2%). Results. Across all BMI groups, nine knees were reported as revised at two years post-operative yielding a two year revision rate of 0.99%, 4 in the overweight group, 2 in the obese class I group and 3 in the obese class II group. There was no significant difference in the rate of revision between the BMI groups (c. 2. (4, N = 887) = 6.04, p = 0.20). Of the 3 revisions for tibial component loosening, one occurred in the overweight group, one in the obese group and one in the morbidly obese group. The overall patient satisfaction rate for the entire population was 92% with the following distribution: normal: 92%, overweight: 93%, obese class I: 92%, obese class II: 87% and obese class III: 83%. While the most severely obese patients tended to be less satisfied, this was not statistically significant between the groups (c. 2. (4, N = 887) = 5.12, p = 0.27). Conclusion. These results suggest that BMI does not effect the survivorship or the satisfaction of patients undergoing robotically assisted UKA. Advancement in UKA implant designs and improvements in surgical technique may help to broaden indications and patient selection for UKA. This study will continue to track patients mid to long term to determine the longer term effect of robotically assisted UKA on high BMI patients

A number of studies have reported longer length of hospital stay (LOS) after surgery in patients with higher ASA grades. The impact of Body Mass Index (BMI) on LOS after Total Hip Replacement (THR) remains unclear with conflicting findings in reported literature. In our hospital we strongly encourage all patients with a raised BMI to participate in a weight reduction programme prior to surgery. This prompted us to investigate the impact BMI has on LOS compared to the more established impact of ASA grade. A retrospective analysis was conducted on all elective primary THR patients between 11/2013 to 02/2014. LOS in BMI groups <30, 30–39 and ≥40 and ASA grades 1–2 and 3–4 was compared. Where appropriate, independent t-test and non-parametric Mann-Whitney test were used to predict significance. 122 THR were analysed. Mean LOS in BMI groups <30, 30–39 and ≥40 were 5.6, 6.2 and 8.0 days, respectively. This was not predicted significant (p=0.7). Mean LOS in ASA groups 1–2 and 3–4 were 5.2 and 9.3, respectively. This was predicted significant (p-value < 0.01). In patients undergoing primary THR, ASA grade is a better predictor of LOS than BMI. Our data adds to the evidence that high BMI alone is not a significant factor in prolonging LOS after a primary THR. This should be taken into account when allocating resources to optimise patients for surgery

Introduction. Total knee arthroplasty (TKA) implant systems offer a range of sizes for orthopaedic surgeons to best mimic the patient's anatomy and restore joint function. From a biomechanical perspective, the challenge on the TKA implants is affected by two factors: design geometry and in vivo load. Larger geometry typically means more robust mechanical structure, while higher in vivo load means greater burden on the artificial joint. For an implant system, prosthesis geometry is largely correlated with implant size, while in vivo load is affected by the patient's demographics such as weight and height. Understanding the relationships between implant size and patients' demographics can provide useful information for new prosthesis design, implant test planning, and clinical data interpretation. Utilizing a manufacturer supported clinical database, this study examined the relationships between TKA patient's body weight, height, and body mass index (BMI) and the received implant size of a well-established implant system. Methods. A multi-site clinical database operated by Exactech, Inc. (Gainesville, FL, USA) was utilized for this study. The database contains patient information of Optetrak TKA implant recipients from over 30 physicians in US, UK, and Colombia since 1995. Nine implant sizes (0, 1, 2, 2.5, 3, 3.5, 4, 5 and 6) are seen in the database, while size 0 was excluded due to very low usage. Taking primary TKA only, a total of 2,713 cases were examined for patient's body weight, height, BMI, and their relationships with the implant size. Results. Both patient's weight and height strongly correlate with implant size (R. 2. »0.95 for both parameters with a linear regression). On average, the increase of one implant size corresponds to an increase of 7.4 kg in patient's weight and 7.0 cm in patient's height (Figure 1). However, there is almost no dependency between patient's BMI and implant size (R. 2. <0.05), and the regression line is almost flat (k=-0.08) (Figure 1). Discussion. Based on the Exactech database, this study revealed that TKA patients' weight and height increase close-to-linearly with implant size, but BMI stays fairly constant. These relationships are not all intuitive mathematically, and are likely simplified representations of higher order functions within the particular variable ranges. The most interesting finding was the independence of BMI on implant size, which provides a favorable validation of the geometry design and size selection of the Optetrak implant system. BMI (kg/m. 2. ) has the same unit dimension as stress (N/m. 2. ) excluding the constant g (9.8 N/kg). Since implant geometry is generally proportional to patient height, and joint force is generally proportional to patient weight, the mechanical stress imposed on the implant would be generally proportional to patient's BMI. The fact that BMI stays constant across sizes indicates that the implant system would experience a similar level of stress across all sizes, which has been previously observed in femorotibial contact stress analyses on the Optetrak system. This study showed that a heavier TKA patient statistically tends to receive a larger implant which, depending on implant design, will provide larger contact area and compensate for the higher load

BACKGROUND. Some papers recently reported conflicting results on implant survivorship in all-poly tibial UKRs. Furthermore, the influence of BMI on this specific implant survivorship remains unclear, since existing reports are often based on small series of non-consecutive patients with different follow up durations, enabling to generate meaningful conclusions. PURPOSE. To determine the 10-years survival rate of an all-poly tibial UKR in a large series of consecutive patients and to investigate whether a correlation exists between a higher BMI and an increased risk of revision for any reason. METHODS. A retrospective evaluation of 273 patients at 6 to 13 years of follow-up was performed. Clinical evaluation was based on KSS and WOMAC scores. Subjective evaluation was based on a VAS for pain self-assessment. Radiographic evaluation was performed by 3 independent observers. A Kaplan-Meier survival analysis was performed assuming revision for any reason as primary endpoint. Reason of revision was determined basing on clinical and radiographic data. RESULTS. The 10-years implant survivorship was 90.8%. Twenty-five revisions (9.2%) were performed and aseptic loosening of the tibial component was the most common failure mode (11 cases, 4%). No significant correlation was identified between failure and patients'BMI. Mean post-operative results for KSS and WOMAC score were 87.0 (st.dev. 14.6) and 87.37 (st.dev. 11.48), respectively. VAS showed a significant improvement (p<0.0001) respect to pre-operative condition. CONCLUSIONS. Unlike some recent reports, this study demonstrated a satisfactory 10-years implant survivorship using an all-poly tibial UKR. A higher BMI does not reduce survival rate at 6 to 13 years of follow-up

Purpose. Weight loss is often advised to our patients and considered to make a substantial difference in most musculoskeletal symptoms. Patients with end stage ankle arthrosis have severe pain, diminished health related quality of life, and limited physical function. They frequently refer to increased weight as a simple indicator of decline in their quality loose weight. Patients assume that weight loss will follow after surgery secondary to increased activity with reduced pain and disability. Method. Changes in the body mass index, mental and physical component of SF36 and Ankle Scale Osteoarthritis of 145 overweight and obese patients after ankle surgery were assessed up to five year after surgery with a mean of 37.1 month follow up from 2002 to 2009. Results. The Ankle Osteoarthritis Scale and Physical component of SF36 significantly improved, by a mean of 34.8, 9.8, respectively after ankle surgery but there was not significant change in Body mass index. Conclusion. Pain and disability of end stage ankle arthritis usually resolve gradually within one and two year after surgery but body mass index changes was insignificant in five year period. In fact following successful ankle fusion or replacement, 1/3 of our patients gained 1 unit BMI or more, 1/3 lost one unit BMI or more and 1/3 remained within one unit of their pre op BMI. This suggests that obesity is a multifactorial and an independent disease

Introduction. Stiffness after total knee arthroplasty is a common occurrence. Despite its prevalence, little is known as to which patients are at risk for poor range of motion after total knee arthroplasty. The purpose of this study was to determine the risk factors for manipulation under anesthesia (MUA) after total knee arthroplasty (TKA). Methods. Using a single institution registry, 160 patients who underwent a manipulation under anesthesia after total knee arthroplasty between 2007 and 2013 were retrospectively evaluated. Each patient was 1:1 matched by age, gender and laterality to a control group of 160 patients who did not require MUA after TKA. Risk factors for MUA were assessed, and included medical co-morbidities, BMI, prior operations, and preoperative range of motion. Results. There were 160 patients in each group, 48 males and 112 females. Patients who required a MUA after TKA had a significantly higher percentage of overweight patients with a BMI >25 (88% vs 76%, p=0.01, Odds ratio=2.18), and previous surgery including arthroscopy (60% vs 33%, P < 0.0001, Odds ratio=3.12). Patients that underwent an MUA had a higher but not significant prevalence of depression and anxiety (22% vs. 16%, p=0.20, Odds Ratio=1.44) and diabetes (15% vs. 8%, p=0.058, Odds Ratio=2.0). Average ROM was 3–110° (Range −10–130°) and 6–102° (Range 0–140°) in the MUA and control groups respectively. In the MUA group, 29% of patients had pre-operative flexion less than 90 degrees pre-operatively compared to 3% in the control group (p=0.02, Odds Ratio=6.6). While the average preoperative range of motion did not differ between the groups, there were a larger percentage of patients with severe limitations in range of motion who ended up needing a MUA after TKA compared to controls. Conclusion. Patients with increased BMI, preoperative range of motion less than 90°, and a history of prior operations should be counseled on the increased risk of requiring a MUA after TKA

There is mixed evidence in the literature regarding increasing age, ASA and BMI as risk factors for surgical site infection in orthopaedic surgery. To investigate the matter further, we examined 1055 wounds in 1008 patients in the Department of Trauma and Orthopaedic Surgery at University College London Hospital between 2000 and 2006. All patients with a minimum two-night stay were included. Data was collected by four designated research nurses. The age, height, weight and ASA status of each patient was recorded. All wounds were classified using ASEPSIS. This is a quantitative wound scoring method which is a summation of scores calculated from visual wound characteristics and the clinical consequences of infection. Our results showed a strong linear association between age and ASEPSIS scores. Single variable regression analysis showed a t value of 3.32 and p value of 0.001. A similar linear association was seen between ASA grading and ASEPSIS scores. Single variable regression analysis showed a t value of 2.75 and p value of 0.006. The association between BMI and ASEPSIS scores was markedly different from that seen with age and ASA. The graph was U-shaped with patients with a BMI of 25-30 having the lowest average ASEPSIS scores. Patients with a lower and a higher BMI had higher average ASEPSIS scores. Single variable regression analysis was not significant since the relationship between BMI and ASEPSIS scores is not linear. In conclusion, there are clearly defined patient groups who are at increased risk of developing a surgical site infection: older patients, patients with a higher ASA, and patients with both a low and high BMI. These patients should be targeted to reduce overall infection rates. This can be achieved by ensuring adequate antibiotic prophylaxis, having a low threshold to treat suspected infection and arranging regular follow-up

Introduction. We conducted a study of 312 patients undergoing primary hip and knee arthroplasty in 2005. The aim was to identify the correlation between length of stay, ASA (American society of Anaesthesiologist) grade and BMI (Body Mass Index). Method and materials. 312 patients underwent hip and knee arthroplasty in 2005. ASA grade for surgery was documented by the anaesthetist and BMI by the nurses. 67 patients had inadequate documentation. SPSS software was used for analysis. Results. Of the 245 patients; 35 had ASA grade 1, 144 had ASA grade 2, 64 had ASA grade 3 and 2 had ASA grade 4. Mean length of stay for ASA grade 1 was 6.8 days, ASA grade 2 was 9.75 days, ASA grade 3 was 12.5 days and ASA grade 4 was 13.5 days. There was significant positive correlation (p < 0.01) between the ASA grade and post-operative length of stay. BMI was graded as I (<18.5), II (18.5-24.9), III (25-29.9) and IV (>30). There was no correlation (Pearson's correlation coefficient = 0.184) between BMI and post-operative length of stay. Conclusion. As the ASA grade increases the length of stay in hospital increases. ‘Cherry picking’ of ASA grade I and II patients by the ISTC will increase the average length of stay in NHS hospitals resulting in increased cost. Length of stay on its own is not a good indicator of hospital performance

Two big problems exist with the all polyethylene cemented tibial component; the polyethylene and the cement. The polyethylene is too weak and flexible to bear high tibial load, so it deforms and loosens. The interface stresses are too high when two flexible structures are poorly bonded and heavily loaded.

Modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80's for versatility and to facilitate screw fixation for cementless implants. These designs allow exchange of various polyethylene thicknesses, and aids the addition of stems and wedges. Other advantages include the reduction of inventory, and the potential for isolated tibial polyethylene exchanges as a simpler revision procedure. Several studies have documented the high failure rate of isolated polyethylene exchange procedures, because technical problems related to the original components are left uncorrected. However, revision for wear is the simplest revision ever!

Since the late 1980's the phenomena of polyethylene wear and osteolysis have been observed much more frequently when compared with earlier eras. The reasons for this increased prevalence of synovitis, progressive osteolysis, and severe polyethylene wear remain unclear. There is some association with the widespread use of both cementless and cemented modular tibial designs. Improved polyethylene attachment is the answer even if a screw, a wire, or a pin is needed. Do not abandon the modular tibia.

Aims. There is little published on the outcomes after restarting elective orthopaedic procedures following cessation of surgery due to the COVID-19 pandemic. During the pandemic, the reported perioperative mortality in patients who acquired SARS-CoV-2 infection while undergoing elective orthopaedic surgery was 18% to 20%. The aim of this study is to report the surgical outcomes, complications, and risk of developing COVID-19 in 2,316 consecutive patients who underwent elective orthopaedic surgery in the latter part of 2020 and comparing it to the same, pre-pandemic, period in 2019. Methods. A retrospective service evaluation of patients who underwent elective surgical procedures between 16 June 2020 and 12 December 2020 was undertaken. The number and type of cases, demographic details, American society of Anesthesiologists (ASA) grade, BMI, 30-day readmission rates, mortality, and complications at one- and six-week intervals were obtained and compared with patients who underwent surgery during the same six-month period in 2019. Results. A total of 2,316 patients underwent surgery in 2020 compared to 2,552 in the same period in 2019. There were no statistical differences in sex distribution, BMI, or ASA grade. The 30-day readmission rate and six-week validated complication rates were significantly lower for the 2020 patients compared to those in 2019 (p < 0.05). No deaths were reported at 30 days in the 2020 group as opposed to three in the 2019 group (p < 0.05). In 2020 one patient developed COVID-19 symptoms five days following foot and ankle surgery. This was possibly due to a family contact immediately following discharge from hospital, and the patient subsequently made a full recovery. Conclusion. Elective surgery was safely resumed following the cessation of operating during the COVID-19 pandemic in 2020. Strict adherence to protocols resulted in 2,316 elective surgical procedures being performed with lower complications, readmissions, and mortality compared to 2019. Furthermore, only one patient developed COVID-19 with no evidence that this was a direct result of undergoing surgery. Level of evidence: III. Cite this article: Bone Jt Open 2022;3(1):42–53

Aims. The new COVID-19 variant was reported by the authorities of the UK to the World Health Organization (WHO) on 14 December 2020. We aim to describe the clinical characteristics and nosocomial infection rates in major trauma and orthopaedic patients comparing the first and second wave of COVID-19 infection. Methods. A retrospective analysis of a prospectively collected trauma database was reviewed at a level 1 major trauma centre from 1 December 2020 to 18 February 2021 looking at demographics, clinical characteristics, and nosocomial infections and compared to our previously published first wave data (26 January 2020 to 14 April 2020). Results. From 1 December 2020 to 18 February 2021, 522 major trauma patients were identified with a mean age of 54.6 years, and 53.4% (n = 279) were male. Common admissions were falls (318; 60.9%) and road traffic accidents (RTAs; 71 (13.6%); 262 of these patients (50.2%) had surgery. In all, 75 patients (14.4%) tested positive for COVID-19, of which 51 (68%) were nosocomial. Surgery on COVID-19 patients increased to 46 (61.3%) in the second wave compared to 13 (33.3%) in the first wave (p = 0.005). ICU admissions of patients with COVID-19 infection increased from two (5.1%) to 16 (20.5%), respectively (p = 0.024). Second wave mortality was 6.1% (n = 32) compared to first wave of 4.7% (n = 31). Cardiovascular (CV) disease (35.9%; n = 14); p = 0.027) and dementia (17.9%; n = 7); p = 0.030) were less in second wave than the first. Overall, 13 patients (25.5%) were Black, Asian and Minority ethnic (BAME), and five (9.8%) had a BMI > 30 kg/m. 2. The mean time from admission to diagnosis of COVID-19 was 13.9 days (3 to 44). Overall, 12/75 (16%) of all COVID-19 patients died. Conclusion. During the second wave, COVID-19 infected three-times more patients. There were double the number of operative cases, and quadruple the cases of ICU admissions. The patients were younger with less dementia and CV disease with lower mortality. Concomitant COVID-19 and the necessity of major trauma surgery showed 13% mortality in the second wave compared with 15.4% in the first wave. In contrast to the literature, we showed a high percentage of nosocomial infection, normal BMI, and limited BAME infections. Cite this article: Bone Jt Open 2021;2(8):661–670

Background. Obesity has been linked with increased rates of knee osteoarthritis. Limited information is available on the survival and functional outcome results of rTKR in the obese patients. This registry-based study aimed to identify whether BMI is an independent risk factor for poorer functional outcomes and /or implant survival in rTKA. Methods. New Zealand Joint Registry (NZJR) data of patients who underwent rTKA from 1st January 2010 to January 2023 was performed. Demographics, American Society of Anesthesiologists (ASA), BMI, Operative time, indications for revision and components revised of the patients undergoing rTKA was collected. Oxford knee score (OKS) at 6 months and rates of second revision (re- revision) were stratified based on standardised BMI categories. Results. Of the 2687 revisions, functional outcome scores were available for 1261 patients. Oxford knee scores following rTKA are significantly inferior in higher BMI patients (36.5 vs 31.5 p<0.001). This held true when adjusted for age (35.7 vs 30.9 p<0.001). Tibial component loosening was a more common indication for revision in patients with BMI >40 (31.1% vs 21% for BMI <25), whereas periprosthetic femoral fracture was significantly more commonly seen in patients with BMI <25. Re-revision rates displayed no significant differences between any pairs of BMI groups (2.18/100 component years) and adjusting for age and sex did not alter this (p= 0.462). Indications for re-revision were also not different between BMI categories. Over 50% of the rTKA patients were obese. Significantly more obese patients were ASA grade 3,4 and more were <75 years. Operative time was longer in the obese patients (p<0.001). Conclusions. Although overall re-revision rates are similar between all BMI categories, the functional outcomes favour those with lower BMI. Patients with higher BMI are younger, more comorbid and carry potentially higher perioperative risks. The registry data provides valuable information when providing counsel to patients undergoing rTKA and lends further support to optimising patients prior to pTKA

Increased collection of patient-reported outcome measures (PROM) in registries enables international comparison of patient-centered outcomes after knee and hip replacement. We aimed to investigate 1) variations in PROM improvement, 2) the possible confounding factor of BMI, and 3) differences in comorbidity distributions between registries. Registries affiliated with the International Society of Arthroplasty Registries (ISAR) or OECD membership countries were invited to report aggregate EQ-5D, OKS, OHS, HOOS-PS and KOOS-PS values. Eligible patients underwent primary total, unilateral knee or hip replacement for osteoarthritis within three years and had completed PROMs preoperatively and either 6 or 12 months postoperatively, excluding patients with subsequent revisions. For each PROM cohort, Chi-square tests were performed for BMI distributions across registries and 12 predefined PROM strata (male/female, age 20-64/65-74/>75, high or low preoperative PROM scores). Comorbidity distributions were reported for available comorbidity indexes. Thirteen registries from 9 countries contributed data, n~130000 knee (range 140 to 79848) and n~113000 hip (range 137 to 85281). Mean EQ-5D index values (10 registries) ranged from 0.53 to 0.71 (knee) and 0.50 to 0.70 (hips) preoperatively and 0.78 to 0.85 (knee) and 0.83 to 0.87 (hip) postoperatively. Mean OKS (6 registries) ranged from 19.3 to 23.6 preoperatively and 36.2 to 41.2 postoperatively. Mean OHS (7 registries) ranged from 18.0 to 23.2 preoperatively and 39.8 to 44.2 postoperatively. Four registries reported KOOS-PS and three reported HOOS-PS. Proportions of patients with BMI >30 ranged from 35 to 62% (10 knee registries) and 16 to 43% (11 hip registries). For both knee and hip registries, distributions of patients across six BMI categories differed significantly among registries (p30 were for patients in the youngest age groups (20 to 64 and 65 to 74 years) with the lowest baseline scores. Additionally, females with lowest preoperative PROM scores had highest BMI. These findings were echoed for the OHS and OKS cohorts. Proportions of patients with ASA scores ≥3 ranged from 7 to 42% (9 knee registries) and 6 to 35% (8 hip registries). PROM-score improvement varies between international registries, which may be partially explained by differences in age, sex and preoperative scores. BMI and comorbidity may be relevant to adjust for

To describe the longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing TKA and the associated impact on complications and lengths of hospital stay. We identified patients who underwent primary TKA between 2006 – 2017 within the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We recorded patient demographics, length of stay (LOS), and 30-day major and minor complications. We labelled those with an obese Body Mass Index (BMI ≥ 30), hypertension, and diabetes as having MetS. We evaluated mean BMI, LOS, and 30-day complication rates in all patients, obese patients, and those with MetS from 2006-2017. We used multivariable regression to evaluate the trends in BMI, complications, and LOS over time in all patients and those with MetS, and the effect of BMI and MetS on complication rates and LOS, stratified by year. 270,846 patients underwent primary TKA at hospitals participating in the NSQIP database. 63.71% of patients were obese (n = 172,333), 15.21% were morbidly obese (n = 41,130), and 12.37% met criteria for MetS (n = 33,470). Mean BMI in TKA patients increased at a rate of 0.03 per year (0.02-0.05; p < 0 .0001). Despite this, the rate of adverse events in obese patients decreased: major complications by an odds ratio (OR) of 0.94 (0.93-0.96; p < 0 .0001) and minor complications by 0.94 (0.93-0.95; p < 0 .001). LOS also decreased over time at an average rate of −0.058 days per year (-0.059 to −0.057; p < 0 .0001). The proportion of patients with MetS did not increase, however similar improvements in major complications (OR 0.94 [0.91-0.97] p < 0 .0001), minor complications (OR 0.97 [0.94-1.00]; p < 0 .0330), and LOS (mean −0.055 [-0.056 to −0.054] p < 0 .0001) were found. In morbidly obese patients (BMI ≥ 40), there was a decreased proportion per year (OR 0.989 [0.98-0.994] p < 0 .0001). Factors specifically associated with major complications in obese patients included COPD (OR 1.75 [1.55-2.00] p < 0.0001) and diabetes (OR 1.10 [1.02-1.1] p = 0.017). Hypertension (OR 1.12 [1.03-1.21] p = 0.0079) was associated with minor complications. Similarly, in patients with MetS, major complications were associated with COPD (OR 1.72 [1.35-2.18] p < 0.0001). Neuraxial anesthesia was associated with a lower risk for major complications in the obese cohort (OR 0.87 [0.81-0.92] p < 0.0001). BMI ≥ 40 was associated with a greater risk for minor complications (OR 1.37 [1.26-1.50] p < 0.0001), major complications (1.11 [1.02-1.21] p = 0.015), and increased LOS (+0.08 days [0.07-0.09] p < 0.0001). Mean BMI in patients undergoing primary TKA increased from 2006 - 2017. MetS comorbidities such as diabetes and hypertension elevated the risk for complications in obese patients. COPD contributed to higher rates of major complications. The obesity-specific risk reduction with spinal anesthesia suggests an improved post-anesthetic clinical course in obese patients with pre-existing pulmonary pathology. Encouragingly, the overall rates of complications and LOS in patients with obesity and MetS exhibited a longitudinal decline. This finding may be related to the decreased proportion of patients with BMI ≥ 40 treated over the same period, possibly the result of quality improvement initiatives aimed at delaying high-risk surgery in morbidly obese patients until healthy weight loss is achieved. These findings may also reflect increased awareness and improved management of these patients and their elevated risk profiles

Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative calcar fractures, post-operative fractures and dislocations were not associated with worse OHS. Patients with increased BMI had worse pre and post-operative hip functions yet, there was a significant multivariate association between increased BMI and increased improvement in OHS from pre-op to 1 year in women aged 55–80 and men under the age of 60. Femoral stem size increases with age but decreases in male patients over 80. There was no difference found in OHS between bilateral hip replacements and unilateral, nor was there any change found with laterality side of the replacement. Conclusions. This study suggests that ageing >70 is not associated with poorer outcomes despite small number of revisable complication rates that increase with age from 50 upwards. Men had marginally higher average OHS than women At 1 year. Higher BMI or ASA scores are associated with worse pre-operative hips and worse final outcome score. Despite this, the Delta OHS increases with increased BMI shown in the 55–80 year old female patients and male patients under 60. Key Words: THR, Uncemented, Oxford hip score, outcome

Total hip arthroplasty (THA) is performed under general anesthesia (GA) or spinal anesthesia (SA). The first objective of this study was to determine which patient factors are associated with receiving SA versus GA. The second objective was to discern the effect of anesthesia type on short-term postoperative complications and readmission. The third objective was to elucidate factors that impact the effect of anesthesia type on outcome following arthroplasty. This retrospective cohort study included 108,905 patients (median age, 66 years; IQR 60-73 years; 56.0% females) who underwent primary THA for treatment of primary osteoarthritis in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database during the period of 2013-2018. Multivariable logistic regression analysis was performed to evaluate variables associated with anesthesia type and outcomes following arthroplasty. Anesthesia type administered during THA was significantly associated with race. Specifically, Black and Hispanic patients were less likely to receive SA compared to White patients (White: OR 1.00; Black: OR 0.73; 95% confidence interval [CI] 0.71-0.75; Hispanic: OR 0.81; CI, 0.75-0.88), while Asian patients were more likely to receive SA (OR 1.44, CI 1.31-1.59). Spinal anesthesia was associated with increased age (OR 1.01; CI 1.00-1.01). Patients with less frailty and lower comorbidity were more likely to receive SA based on the modified frailty index ([mFI-5]=0: OR 1.00; mFI-5=1: OR 0.90, CI 0.88-0.93; mFI-5=2 or greater: OR 0.86, CI 0.83-0.90) and American Society of Anesthesiologists (ASA) class (ASA=1: OR 1.00; ASA=2: OR 0.85, CI 0.79-0.91; ASA=3: OR 0.64, CI 0.59-0.69; ASA=4-5: OR 0.47; CI 0.41-0.53). With increased BMI, patients were less likely to be treated with SA (OR 0.99; CI 0.98-0.99). Patients treated with SA had less post-operative complications than GA (OR 0.74; CI 0.67-0.81) and a lower risk of readmission than GA (OR 0.88; CI 0.82-0.95) following THA. Race, age, BMI, and ASA class were found to affect the impact of anesthesia type on post-operative complications. Stratified analysis demonstrated that the reduced risk of complications following arthroplasty noted in patients treated with SA compared to GA was more pronounced in Black, Asian, and Hispanic patients compared to White patients. Furthermore, the positive effect of SA compared to GA was stronger in patients who had reduced age, elevated BMI, and lower ASA class. Among patients undergoing THA for management of primary osteoarthritis, factors including race, BMI, and frailty appear to have impacted the type of anesthesia received. Patients treated with SA had a significantly lower risk of readmission to hospital and adverse events within 30 days of surgery compared to those treated with GA. Furthermore, the positive effect on outcome afforded by SA was different between patients depending on race, age, BMI, and ASA class. These findings may help to guide selection of anesthesia type in subpopulations of patients undergoing primary THA

Obesity is a common in individuals undergoing arthroplasty, and the potential for weight loss with improved mobility may be expected by some. The aim of this study was 1. determine the proportion that achieved weight loss after hip or knee arthroplasty, and 2. examine the effect of obesity on patient reported outcomes (PROMS) and satisfaction with surgery. Participants underwent primary TKA or THA between July 2015 and December 2020 and consented to participation in a research database with baseline PROMS, including weight, BMI, Oxford Knee, or Hip Score, and EQ5D. Participants repeated PROMS at 12 months after surgery with additional questions regarding satisfaction with surgery. 3449 patients completed PROMS 1 year after arthroplasty with weight and BMI. There were 1810 THA and 1639 TKA procedures. The mean baseline BMI was higher in TKA (29.8, SD 5.2) compared to THA (27.7, SD 5.0), p=0.001. A higher proportion of TKA were classified as obese class 1 (29% TKA, 19% THA), obese class 2 (11% TKA and 6% THA), and obese class 3 (5% TKA and 2% THA), p=0.001. The mean weight loss after 1 year was 0.4kg and 0.9kg in obese THA subjects and TKA subjects respectively. In the obese >5kg weight loss was achieved in 13% of TKA and 7% of THA (p=0.001). Obese experienced equivalent improvement in Oxford scores, compared to non-obese subjects. Satisfaction with surgery was reported by 95% of THA and 91% of TKA subjects with no significant differences between BMI group grades (p=0.491 THA and p=0.473 TKA). Preoperative obesity was observed in 44% of TKA and 27% of THA subjects. In the obese only 1 in 10 subjects lost 5kg or more over 12 months. Obese patients experienced equivalent improvements in outcome after arthroplasty and rates of satisfaction with surgery to the non-obese

The aim of this study was to examine the incidence of obesity in patients undergoing primary total shoulder replacement (TSR) (stemmed and reverse) for osteoarthritis (OA) in Australia compared to the incidence of obesity in the general population. A 2017–18 cohort of 2,621 patients from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) who underwent TSR, were compared with matched controls from the Australian Bureau of Statistics (ABS) National Health Survey from the same period. The two groups were analysed according to BMI category, sex and age. According to the 2017–18 National Health Survey, 35.6% of Australian adults are overweight and 31.3% are obese. Of the primary TSR cases performed, 34.2% were overweight and 28.6% were obese. The relative risk of requiring TSR for OA increased with increasing BMI category. Class-3 obese females, aged 55–64, were 8.9 times more likely to require TSR compared to normal weight counterparts. Males in the same age and BMI category were 2.5 times more likely. Class-3 obese patients underwent TSR 4 years (female) and 7 years (male) sooner than their normal weight counterparts. Our findings suggest that the obese population is at risk for early and more frequent TSR for OA. Previous studies demonstrate that obese patients undergoing TSR also exhibit increased risks of longer operative times, higher superficial infection rates, higher periprosthetic fracture rates, significantly reduced post-operative forward flexion range and greater revision rates. Obesity significantly increases the risk of requiring TSR. To our knowledge this is the first study to publish data pertaining to age and BMI stratification of TSR Societal efforts are vital to diminish the prevalence and burden of obesity related TSR. There may well be reversible pathophysiology in the obese population to address prior to surgery (adipokines, leptin, NMDA receptor upregulation). Surgery occurs due to recalcitrant or increased pain despite non-op Mx