Abstract. Introduction. Risk factors for osteoarthritis include raised BMI and female gender. Whether these two factors influenced synovial gene expression was investigated using a triangulation and modelling strategy which generated 12 datasets of gene expression in synovial tissue from three knee pathologies with matching BMI groups, obese and overweight, and gender distributions. Methodology. Intra-operative synovial biopsies were immersed in RNAlater at 4oC before storage at -80oC. Total RNA was extracted using RNAeasy with gDNA removal. Following RT- PCR and quality assessment, cDNA was applied to Affymetrix Clariom D microarray gene chips. Bioinformatics analyses were performed. Linear models were prepared in limma with gender and BMI factors incorporated sequentially for each pathology comparison, generating 12 models of probes differentially expressed at FDR p<0.05 and Bayes number, B>0. Data analysis of differently expressed genes utilized Ingenuity Pathway Analysis and Cytoscape with Cluego and Cytohubba plug-ins. Results. Expression of 453 synovial genes was influenced by BMI and gender, 360 encode proteins such as HIF-1a, HSF1, HSPA4, HSPA5. Top canonical pathways include Unfolded protein response, Protein Ubiquiitation and Clathrin mediated endocytosis signalling linked by modulation of heat shock proteins, comparable to pathology dependent regulation. In addition BMI and gender modulate gene expression in the NRF2-mediated oxidative stress response pathway with down regulation of Glutathione-S-transferases potentially down regulating antioxidant defences. Conclusion. The enhanced risk of osteoarthritis induced by an elevated BMI and female gender maybe include differential expression of heat shock proteins and genes in the NRF2 pathway

Introduction. Body mass index (BMI) is a topical area of interest in the field of lower limb arthroplasty. It has been well established that BMI can influence post-operative outcomes. This study compares post-operative outcomes, including satisfaction rates, length of stay (LOS) and radiographic findings in different BMI groups following total hip arthroplasty (THA). Methods. We retrospectively evaluated all non-navigated THAs performed at our institution from 2006–2016. Case-notes were reviewed for dichotomised satisfaction score, LOS and radiographic parameters including inclination, anteversion, limb length discrepancy (LLD) and offset discrepancy. Patients were classified into 4 groupings based on BMI (underweight (<24.5), healthy (24.5–30), obese (30–40), severely obese (>40)). Appropriate statistical analyses were performed to identify between group differences. Results. A total of 6874 patients were included for analysis, (Male=2807, Female=4067, Age = 68.1, BMI=29.60). Satisfaction rates at 3 months and 1 year and LOS according to BMI are displayed in Table 1. Radiographic findings grouped by BMI are displayed in Table 2. Discussion/Conclusion. Satisfaction rates for all categories of BMI were excellent at 3 months (96.90%-98.02%) and 12 months (95.94%-98.32%), with no clinically significant differences between groups. BMI was associated with a significantly longer LOS for the underweight and the severely obese compared to the healthy group. There was no clinically significant influence of BMI on any of the radiographic findings reported. The obese and severely obese groups were significantly younger than the underweight and healthy groups, indicating BMI does appear to have an effect on the age where THA is considered a suitable treatment option in this patient group. For any figures or tables, please contact the 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

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

The effect of BMI on patient-reported outcomes following total ankle replacement (TAR) is uncertain and the change in BMI experienced by these patients in the 5 years following surgery has not been studied. We report a series of 106 patients with complete 5-year data on BMI and patient-reported outcome scores. Patients undergoing TAR between 2006 and 2009, took part in the hospital joint registry, which provides routine clinical audit of patient progress following total joint arthroplasty; therefore, ethics committee approval was not required for this study. Data on BMI, Foot and Ankle Score (FAOS) and SF-36 score were collected preoperatively and annually postoperatively. Patients who were obese (BMI >30) had lower FAOS scores pre-operatively and at 5 years, however this did not reach significance. Both obese (p = 0.0004) and non-obese (p < 0.0001) patients demonstrated a significant improvement in FAOS score from baseline to 5 years. This improvement was more marked for the non-obese patients. No significant differences were seen for SF36 scores between obese and non-obese patients either at baseline or 5 years. There was a trend for improved score in both groups. Mean pre-operative BMI was 28.49. Mean post-operative BMI was 28.33. The mean difference between pre- and post-operative BMI was −0.15, which was not statistically significant (p=0.55). There were no significant differences in revisions in the obese (2) and non-obese (1 and one awaited) groups at 5 years. This data supports use of TAR in the obese population, as significant increases in mean FAOS score were seen in this group at 5 years. Obesity did not have a significant influence on patients' overall health perceptions, measured by the SF36 and a trend for improvement was seen in both obese and non-obese patients. TAR cannot be relied upon to result in significant post-operative weight-loss without further interventions

Background. Increasing number of studies investigating surgical patients have reported longer length of stay (LOS) in hospital after an operation with higher ASA grades. However, the impact of Body Mass Index (BMI) on LOS in hospital post Total Knee Replacement (TKR) remains a controversial topic with conflicting findings in reported literature. In our institution, we recently adopted a weight reduction program requiring all patients with raised BMI to participate in order to be considered for elective TKR. Objectives. This has prompted us to investigate the impact BMI has on LOS compared to the more established impact of ASA grade on patients following Primary TKR. Methods. A retrospective analysis was conducted on all elective primary TKR patients between November 2013 and May 2014. LOS was compared in BMI groups <30, 30–40 and >40 and ASA grades 1–2 and 3–4. ANOVA and independent t-test were used to compare mean LOS between BMI groups and ASA grades, respectively. Results. Two hundred and thirty six TKR were analysed. Mean LOS in BMI groups <30, 30–40 and >40 were 6.0, 6.4 and 6.0 days, respectively (p = 0.71). Mean LOS in ASA groups 1–2 and 3–4 were 5.8 and 7.6, respectively (p < 0.01). Conclusions. In patients undergoing primary TKR, ASA grade is a better predictor of LOS than BMI. Our data further adds to the evidence that high BMI alone is not a significant factor in prolonging LOS after a primary TKR. This should be taken into account when allocating resources to optimise patients for surgery. Level of evidence. III - Evidence from case, correlation, and comparative studies

Obesity is considered a risk factor to a successful outcome in total knee arthroplasty. The prevalence of obesity is causing concern as risks associated with obesity are well documented and the incidence of obesity is increasing in the Australian population. Previous studies have not reached a consensus on the relationship of BMI and short term outcomes of total knee arthroplasty. The aims of this study were to evaluate the relationship between BMI and the degree of flexion achieved at discharge and to determine the influence of BMI on pre and postoperaive range of motion, duration of surgery, analgesia requirements and duration of stay. Obesity is defined as a body mass index (BMI) of greater than 30 KG/m2. 120 consecutive patients were recruited from patients presenting for total knee arthroplasty (TKA) to two hospitals. They were classified into one of four groups based on their BMI. All patients were assessed pre and postoperatively by the surgical team. Data was collected on type of implant used, duration of surgery, type of anaesthetic, analgesia requirements and length of stay. Knee society scores were collected pre and postoperatively. Three to six month follow-up was conducted by the surgical team to record flexion, ROM and KSS. Statistical analysis was performed using statistical software. 120 patients were available for the study with 61 (50.8%) being classified as obese and 6 patients classified as morbidly obese. (BMI > 40). The average preoperative flexion results were 112.1 degrees (BMI 18.5 to 14.9), 114.0 degrees (BMI 25 to 29.9), 107.0 degrees (BMI 30 and above), while the postoperative flexion prior to discharge was 85 (BMI 18.5 to 24.9), 90.3 (BMI 25 29.9) and 88.3 (BMI 30 or above). The obese patients had a lower ROM preoperatively but there was no Significant difference at discharge. Patients with a BMI of 25–29.9 used the least amount of analgesia and had the fastest surgery time. They also spent the least amount of time in hospital. (6.3 days) Patients classified as clinically obese (BMI 30 and above) recorded the lowest KSS. As BMI increases the postoperative functional knee score decreases but there is no Significant difference at discharge and 3–6 months postoperatively. The increasing prevalence of obesity in the Western world suggests that a Significant proportion of surgical patients will be in the obese or morbidly obese catergory. This studty suggests that BMI alone does not influence the short term outcomes of TKA. The poorer long term outcomes in TKA may be related to other factors. Further research may be appropriate

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

Background. This study aimed to investigate the effect of body mass index (BMI) on functional outcome following hip preservation surgery using the U.K. Non-Arthroplasty Hip Registry (NAHR). Methods. Data on adult patients who underwent hip arthroscopy or periacetabular osteotomy (PAO) between January 2012 and December 2018 was extracted from the UK Non-Arthroplasty Hip Registry dataset allowing a minimum of 12 months follow-up. Data is collected via an online clinician and patient portal. Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months. Results. A total of 6,666 patients were identified with BMI data available in 52%, comprising 3,220 arthroscopies and 277 PAO. Patients were divided into WHO groups: <25kg/m. 2. (n=1,745 (49.8%)), 25–30kg/m. 2. (n=1,199 (34.2%)), and ≥30kg/m. 2. (n=562 (16.0%)). Patients with higher BMI tended to be older. Pre-operative, 6 and 12-month follow-up were available for 91%, 49% and 45% of cases respectively. Higher BMI was associated with significantly poorer baseline, 6- and 12-month outcomes (12-month mean iHOT-12 score: <25kg/m. 2. = 62.3 (95%CI 60.4 to 64.3), 25–30kg/m. 2. = 57.3 (95%CI 55.0 to 59.7), ≥30kg/m. 2. = 54.7 (95%CI 51.1 to 58.2)). However, all groups saw similar and statistically significant improvement in pre- vs post-op scores (mean 12-month iHOT-12 gain: <25kg/m. 2. = +27.1 (95%CI 25.1 to 29.0), 25–30kg/m. 2. = +26.5 (95%CI 24.0 to 29.0), ≥30kg/m. 2. = +26.8 (95%CI 23.2 to 30.4), between-group p = 0.9). EQ-5D outcomes followed the same trend. Modelling for age, sex and procedure we found no significant difference in 12-month iHOT-12 gain between BMI groups. Conclusion. Whilst obese patients started from, and achieved lower post-operative raw functional scores, all BMI groups saw similar and significant degrees of improvement in functional outcome post-operatively. Obesity should not be considered a contraindication to hip preservation surgery

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

Abstract. Introduction. Medial fix bearing unicompartmental knee replacement (UKR) designs are consider safe and effective implants with many registries data and big cohort series showing excellent survivorship and clinical outcome comparable to that reported for the most expensive and surgically challenging medial UKR mobile bearing designs. However, whether all polyethylene tibial components (all-poly) provided comparable results to metal-backed modular components during medial fix bearing UKR remains unclear. There have been previous suggestions that all-poly tibia UKR implants might show unacceptable higher rates of early failure due to tibial component early loosening especially in high body max index (BMI) patients. This study aims to find out the short and long-term survival rate of all-poly tibia UKR and its relationship with implant thickness and patient demographics including sex, age, ASA and BMI. Material and Methods. we present the results of a series of 388 medial fixed bearing all-polly tibia UKR done in our institution by a single surgeon between 2007–2019. Results. We found out excellent implant survival with this all-poly tibia UKR design with 5 years survival rate: 96.42%, 7 years survival rate: 95.33%, and 10 years survival rate: 91.87%. Only 1.28% had early revision within 2 years. Conclusion. Fixed bearing medial all-poly tibia UKR shows excellent survivor rate at 2, 5, 7 and 10 years follow up and the survival rate is not related with sex, age, BMI, ASA grade or implant thickness. Contrary to the popular belief, we found out that only 1.71% of all implants was revised due to implant loosening

Outcomes for guided motion primary total knee arthroplasty (TKA) in obese patients are unknown. 1,684 consecutive patients underwent 2,059 primary TKAs with a second-generation guided motion implant between 2011–2017 at three European and seven US sites. Of 2,003 (97.3%) TKAs in 1,644 patients with BMI data: average age 64.5 years; 58.4% females; average BMI 32.5 kg/m2; 13.4% had BMI ≥ 40 kg/m2. Subjects with BMI ≥ 40 kg/m2 had longest length of hospital stay (LOS) at European sites; LOS similar at US sites. Subjects with BMI ≥ 40 kg/m2 (P=0.0349) had longest surgery duration. BMI ≥ 40 kg/m2 had more re-hospitalizations or post-TKA reoperations than BMI < 40 kg/m2 (12.7% and 9.2% at five-year post-TKA, P<0.0495). Surgery duration and long-term complication rates are higher in patients with BMI ≥ 40 kg/m2, but device revision risk is not elevated

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

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

Introduction: Obesity is a risk factor to develope knee OA. Patients who are obese often consider their disabling joint disease as a cause for their increased weight. The purpose of this study is to evaluate the changes of weigth and BMI in obese patients after TKA. Methods: 102 obese patients who underwent TKA between January 2002 and December 2003 were evaluated. They were followed for a mean duration of 35 months. Data about age, height, weight, BMI, hypertension, diabetes, NSAIDs and crutches were collected preoperative and at the end of follow-up. Statystical analysis was done using SPSSv11.5. Results: Mean age was 69.8 y.o.. The average height was 157 cm. 24 were men and 78 women. Mean preoperative weight was 86.7 Kgs and at the end of follow-up was 87.3. BMI rose from 35.1 to 35.3. 90% recognized a better quality of life. 12.2% have a better control of their hypertension.30% needs NSAIDs and 4% uses crutches. Conclusions: Obesity leads to an important number of Total Joint Replacement, specially TKA. Apparently it haven’t a worse outcome. Patients doesn’t loose weight after TKA, someones gain it. Knee OA can’t be considered as a cause of overweight.Obesity should be treated as an independent disease

Painful foot and ankle joints are often pointed out as an impeding factor for lack of mobility and weight reduction. There is an assumption that weight loss will occur after their surgery due to increased mobility. The current study aimed to evaluate the effect of surgery on post-operative body mass index (BMI) in patients who underwent mid-foot or hind-foot arthrodesis. Our secondary aim was to look at the effect of sex, pre-operative obesity and good pain relief (AOFAS> 80) on post-operative BMI. All patients who underwent mid-foot and hind-foot arthrodesis between April 2005 and November 2006 were identified from the operating theatre records. Each patient’s BMI recorded pre-operatively was compared with that recorded at a minimum of 6 months postoperatively using the paired Student’s t-test. There were 35 eligible patients. 3 patients were excluded because of multiple trauma and 1 patient died during the period of study. We had 31 patients with 33 procedures with a mean age of 61 years (range 41–80). There were 18 females and 13 males. It was found that there was a mean increase of BMI by 0.25 (95%CI of −.95 to.44; p-value=0.47). It was noted that BMI of patients in obese group (BMI> 30) increased post-operatively by 0.07 (95%CI of −1.52 to 1.66; p-value=0.92). This study highlights the fact that there is no significant effect on BMI in obese patients after successful fusion surgery. The post-operative BMI is neither significantly affected by sex nor quality of pain relief

Introduction: Obesity has become a major public health epidemic, with recent reports citing that 22% of English men and 24% of women are clinically obese. Painful foot and ankle joints are often pointed out as an impeding factor for lack of mobility and weight reduction. There is an assumption that weight loss will occur after their surgery due to increased mobility. The current study aimed to evaluate the effect of surgery on post operative body mass index (BMI) in patients who underwent mid-foot or hind-foot arthrodesis. Patients and Method: All patients who underwent mid-foot and hind-foot arthrodesis under the care of senior author from April 2005 to Nov. 2006 were identified from the operating theatre records. In total 33 procedures were done in 31 patients. Each patient’s BMI recorded pre-operatively was compared with that recorded at a minimum of 6 months postoperatively using the paired Student’s t-test. Analysis of the data was also conducted by stratifying pre-operative BMI, good pain relief (i.e AOFAS> 80), sex and fusion site. Results: It was found that there was a mean increase of BMI by 0.25 (95% CI of −0.95 to 0.44) with p-value of 0.47. It was noted that BMI of patients in obese group increased post-operatively by 0.07 (95% confidence interval of −1.52 to 1.66) with p-value of 0.9. Discussion: This study highlights the fact that there is no significant effect on BMI in obese patients despite significant increase in mobility and pain levels after mid-foot and hind-foot arthrodesis. The change in BMI after fusion surgery is not significantly effected by sex nor quality of pain relief

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