Total Knee Arthroplasty (TKA) in obese patients has been under rigorous scrutiny due concerns of less satisfying results and increased risk of perioperative complications. We conducted a prospective study to observe functional scores between obese and non obese patients at two years after mini-robot computer assisted TKA. Average stay, time for wound to be dry and perioperative complications were also compared. A prospective study was conducted between February 2007 and February 2008 involving 50 patients. Two different groups of 25 each were made on the basis of body mass index (BMI). Oxford and Knee society scores were obtained at two years to observe difference in functional scores between these groups. Rate of post operative complications or hospital stay was comparable between the two groups. Oxford and Knee society scores improved significantly in both the groups postoperatively. Obese patients had better Oxford and Knee society scores, which were not statistically significant. There is no difference in early functional outcome and complications between obese and non obese patients after navigated TKA. Navigated TKA in obese patients help precise component placement with appropriate soft tissue balancing leading to improved results

Background. While tranexamic acid (TXA) has been well shown to reduce blood loss after joint replacement surgery, little is known regarding its effectiveness in obese patients. The aim of this study was to evaluate the effect of TXA changes in hematocrit and hemoglobin levels as well as incidence of packed red blood cell (pRBC) transfusions in obese patients undergoing total joint arthroplasty (TJA). Material and Methods. Between January 2014 and May 2015, 420 consecutive primary joint replacements were performed by two surgeons at our institution. 157 patients (THA=29; TKA=128) were obese with a body mass index (BMI) greater than or equal to 30 kg/m. 2. Medical records were reviewed and identified that TXA was utilized in 85 (54.1%) arthroplasties [study group] and was compared to a consecutive series of 72 (45.9%) TJAs [control group]. TXA was given intravenously(IV) in two doses: (1) one gram prior to incision and (2) one gram at the time of femoral preparation in THA or prior to cementation in TKA. Changes in hemoglobin and hematocrit levels, number of pRBC transfusions, and occurrence of thrombolytic events were recorded. Results. The changes in hematocrit (7.2% vs. 8.1%) and hemoglobin levels (3.0 g/dl vs. 3.3 g/dl) were less for group that received TXA than the control group, albeit not significantly (p=0.100 and p=0.278, respectively). Within the control group 26 (36.1%) patients required a pRBC transfusion with a mean of 2.0 units per patient (range:1–5); whereas, only 8 (9.4%) patients with TXA required a mean of 1.6 units per patient (range:1–2 units). The use of TXA significantly reduced the incidence of pRBC transfusions, especially in TKA (p<0.001). Sub-analyses revealed that transfusion rates were even more significantly reduced by TXA in obesity type II and III. Two pulmonary emboli were reported in the group that did not receive TXA, whereas no thrombolytic events were reported in the group that did receive TXA. Conclusion. Utilization of TXA significantly reduced the rate of pRBC transfusions in obese patients

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

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

Obesity is a known risk factor for hip osteoarthritis. The aim of this study was to compare the incidence of obesity in Australians undergoing hip replacements (HR) for osteoarthritis to the general population. A cohort study was conducted comparing data from the Australian Bureau of Statistics and the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2017-18. Body mass index (BMI) data for patients undergoing primary total hip replacement and resurfacing for osteoarthritis were obtained from the AOANJRR. The distribution of HR patients by BMI category was compared to the general population, in age and sex sub-groups. During the study period, 32,495 primary HR were performed for osteoarthritis in Australia. Compared to the general population, there was a higher incidence of Class I, II, and III obesity in patients undergoing HR in both sexes aged 35 to 74 years old. Class III obese females and males undergoing HR were on average 6 to 7 years younger than their normal weight counterparts. Class III obese females and males aged 55-64 years old were 2.9 and 1.7 times more likely to undergo HR, respectively (p<0.001). There is a strong association between increased BMI and relative risk of undergoing HR. Similar findings have been noted in the United States of America, Canada, United Kingdom, Sweden and Spain. A New Zealand Registry study and recent meta-analysis have also found a concerning trend of Class III obese patients undergoing HR at a younger age. Obese Australians are at increased risk of undergoing HR at a younger age. A national approach to address the prevalence of obesity is needed

Due to shorter hospital stays and faster patient rehabilitation Unicompartmental Knee Replacements (UKR) are now considered more cost effective than Total Knee Joint Replacements (TKJR). Obesity however, has long been thought of as a relative contraindication to UKR due to an unproven theoretical concern of early loosening. This study is a retrospective review of patient reported outcome scores and revision rates of all UKR with recorded BMI performed by the Canterbury District Health Board (CDHB) from January 2011 and September 2021. Patient reported outcome scores were taken preoperatively, at 6 months, 1 year, 5 years and 10 years post operatively. These included WOMAC, Oxford, HAAS, UCLA, WHOQOL, normality, pain and patient satisfaction. 873 patients had functional scores recorded at 5 years and 164 patients had scores recorded at 10 years. Further sub-group analysis was performed based on patient BMI of <25, 25–30, 30–35 and >35. Revision data was available for 2377 UKRs performed in Christchurch during this period. Both obese (BMI >30) and non-obese (BMI <30) patients had significantly improved post-operative scores compared to preoperative. Pre-operatively obese patients had significantly lower functional scores except for pain and UCLA. All functional scores were lower in obese patients at 5 years but this did not meet minimum clinical difference. At 10 years, there was significantly lower HAAS, satisfaction and WOMAC scores for obese patients but no difference in Oxford, normality, WHOQOL, UCLA and pain scores. There was no significant difference in the improvement from pre-operative scores between obese and non-obese patients. All cause revision rate for obese patients at 10 years was 0.69 per 100 observed component years compared to 0.76 in non-obese. This was not statistically significant. Our study proves that UKR is an excellent option in obese patients with post-operative improvement in functional scores and 10 year survivorship equivalent to non-obese patients

Literature has suggested that obese (BMI >30) and morbidly obese (BMI > 35) patients should not be offered surgery as a day case due to increases in complication and readmission rates. At Torbay hospital, patients are routinely offered day case surgery, in a specialist day case unit, regardless of BMI. This is done with minimal complications and enables a higher throughput of patients and at least 75% of surgical procedures to be performed as a day case, as per NHS guidelines. We present 12 year data of day case knee arthroscopy surgery performed at Torbay hospital. Over 12 years, 3421 knee arthroscopies were performed. 649 were performed on obese patients and 222 on morbidly obese patients. No anaesthetic complications were observed in any of the obese patient groups and readmissions rates (up to 28 days) were 0.8% in the morbidly obese group and 0.9% in the Obese group, compared to 0.9% for patients with BMI <30. Our data shows that day case surgery can be performed on all patients regardless of BMI and patient obesity. We believe that other units should offer surgery to obese and morbidly obese patients to allow increased efficiency and achievement of NHS day case guidelines

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

Direct anterior approach (DAA) arthroplasty has generated great interest because of its minimally invasive and muscle sparing nature. Obese patients are reported to be associated with greater incidence of complications in primary joint replacement. The purpose of this study was to compare patient outcomes and complication rates between obese and non-obese patients undergoing primary total hip arthroplasty (THA) through a Bikini direct anterior incision. This retrospective, single surgeon study compared the outcome of 258 obese patients and 200 non-obese patients undergoing DAA THA using a Bikini incision, over a 7-year period. The average follow-up was 4.2 years (range 2.6-7.6 years). There were no statistically significant differences in the complication rate between the two groups. The obese group recorded 2 major (venous thromboembolism and peri-prosthetic fracture) and 2 minor complications (superficial wound infection), compared with the non-obese group, which recorded 2 major (deep-wound infection and peri-prosthetic fracture) and 1 minor complication (superficial wound infection). Patient-reported outcomes (WOMAC and Harris Hip Scores) showed significant post-operative improvements (p < 0.001) and did not differ between the two groups. Bikini DDA THA does not increase the complication rate in obese patients and offers similar clinical improvements compared to non-obese patients. (200 words)

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

In a recent study, 54.5% of patients reporting to arthroplasty clinics in the US were obese. We performed a recent literature review to determine how obesity impacts outcomes in total hip and knee arthroplasty and what must be done to improve outcomes in the obese arthroplasty patient. Specifically, obese patients have shown increased rates of infection, dislocation, need for revision, wound dehiscence, increased operative time and prolonged hospital stay. Additionally, obese TKA patients have been shown to have increased rates of aseptic loosening, thromboembolic events, wound complications, and cardiopulmonary events. Worsening severity of obesity seems to correlate with worsening outcomes and super obesity (BMI>50) has been identified as an independent risk factor for complications. Patients with BMI>35 have shown to be 6.7 times more likely to develop infection after TKA. Patients with BMI>40 have a 3.35 times higher rate of revision for deep infection than those with BMI<35. The odds ratio for major complications increases dramatically beyond BMI>45. How can we improve outcomes in the obese patient? Preoperative care for the obese patient involves nutritional counseling, incorporating weight loss methods, physical therapy, metabolic workup and diagnosis and management of frequent comorbid conditions (OSA, DM2, HTN, HLD, malnutrition, renal failure). Identifying and managing comorbidities is especially important given that some comorbidities such as malnutrition have been shown to be as strong or even stronger an independent risk factor for postoperative TJA complications than obesity. In some cases higher complications were seen which some authors attribute to bariatric patients remaining in a catabolic state after weight loss.  . We know that obesity and its associated comorbid conditions do have worse outcomes and increased complications in TJA patients. We also know that complications proportionately increase with increasing severity of obesity. The super-obese population is at the greatest risk of complication following TJA and preoperative screening and management is essential in reducing complications. Although weight loss is important, bariatric data has shown that it does not solve the problem of obesity in itself and the patient's metabolic state is likely a more important issue. Implant selection is important and strong consideration should be given to avoiding direct anterior approach in the THA obese patient. Understanding of obesity specific complications and treatment options is crucial for patient counseling and optimization to ensure successful treatment in obese TJA patients

We hypothesised that diet-induced obesity (DIO) would result in inferior enthesis healing in a rat model of rotator cuff (RC) repair and that dietary intervention in the peri-operative period would improve enthesis healing. A total of 78 male Sprague-Dawley rats were divided into three weight-matched groups from weaning and fed either: control diet (CD), high-fat diet (HFD), or HFD until surgery, then CD thereafter (HF-CD). After 12 weeks, the left supraspinatus tendon was detached, followed by immediate surgical repair. At 2 and 12 weeks post-surgery, animals were culled, and RCs harvested for biomechanical and histological evaluation. Body composition and metabolic markers were assessed via DEXA and plasma analyses, respectively. DIO was established in the HFD and HF-CD groups before surgery and subsequently reversed in the HF-CD group after surgery. Histologically, the appearance of the repaired entheses was poorer in both the HFD and HF-CD groups compared with the CD group at 12 weeks after surgery, with semiquantitative scores of 6.2 (P<0.01), 4.98 (P<0.01), and 8.7 of 15, respectively. The repaired entheses in the HF-CD group had a significantly lower load to failure (P=0.03) at 12 weeks after surgery compared with the CD group, while the load to failure in the HFD group was low but not significantly different (P=0.10). Plasma leptin were negatively correlated with histology scores and load to failure at 12 weeks after surgery. DIO impaired enthesis healing in this rat RC repair model, with inferior biomechanical and histological outcomes. Restoring normal weight with dietary change after surgery did not improve healing outcomes. Circulating levels of leptin significantly correlated with poor healing outcomes. This pre-clinical rodent model demonstrates that obesity is a potentially modifiable factor that impairs RC healing and increases the risk of failure after RC surgery

Over the last decade, the number of total knee arthroplasty (TKA) has risen over 125%. Numerous studies have established a relationship between obesity and complications in primary TKA. Interestingly, few studies have investigated medical and orthopaedic complications in obese patients undergoing revision TKA (RTKA). With the increasing number of RTKA and with the prevalence of obesity still on the rise, the study of obesity on complications following RTKA is indicated. We retrospectively reviewed 180 RTKA performed by a single surgeon done between August 2008 and June 2017. All patients who underwent RTKA were included, but revisions done with simultaneous extensor mechanism reconstruction and/or distal femur replacement were excluded since these procedures are technically more demanding. 154 revisions met our inclusion/exclusion criteriaes and were included in the final analysis. 81 patients were included in the non-obese group (BMI . The total number of orthopaedic complications in the obese group (46.6%) was significantly higher than in the non-obese group (27.2%) (OR=1.71) (p = 0.01). The number of infection was higher in the obese group (11%) than in the non-obese (6.2%) but this was not statistically significant (OR=1.77) (p = 0.28). Reoperation rate was also higher in the obese group (23.3%) than in the non-obese group (16%) but this did not reach statistical significance (OR=1.46) (p = 0.26) (Table 3). Medical complications were higher in the obese group (31.5% vs 19.8%) (OR=1.59) (p=0.09). According to the Dindo-Clavien classification, the obese group demonstrated a significantly higher rate of grade 3 or higher complications (p = 0.01). Obesity significantly increases the occurrence of orthopaedic complications following RTKA. Obesity also seems to increase the number of medical complications following RTKA. The obese patient should be informed prior to revision TKA that there is an increased risk of complications when compared with the non-obese patient. Further research with higher power would seem advisable to confirm this trend. For any figures or tables, please contact the authors directly

Aim. The aim of this study is to evaluate if obesity negatively affects: (1) complication rate, (2) reoperation and revision rate and (3) functional outcome (based on patient reported outcome measures, PROMs) in revision total hip arthroplasty (rTHA). To our knowledge this is the only recent study to prospectively review these three aspects in what might be considered challenging rTHA. Methods. 444 rTHAs (cup, stem, both, n= 265, 57, 122 respectively), performed in a specialized high-volume orthopaedic center from 2013 to 2015, were prospectively followed. Complications and Oxford Hip Score (OHS) were evaluated at 4 months, 1 year and 2 years. Thirtyfour patients had a BMI >35 kg/m2 (obese), of which thirteen patients with a BMI >40 kg/m2 (morbidly obese). Results. Infection following rTHA was more common in obese patients (8/34: 24%) and in morbidly obese patients (5/13: 38%) than in non-obese patients (15/410: 4%; p's < 0.001). No differences between obese and non-obese groups for other complications were observed (aseptic loosening, dislocation, periprosthetic fractures, thromboembolic events). Reoperation and revision rates were similar overall (p = 0.067 / 0.303 respectively) and due to infection (p = 0.469 / 0.879 respectively) for obese and non-obese groups. Scores on the OHS improved from 42 ±13 at baseline to 27±12 at 1 and 2 year follow-up (p < 0.001). Obese patients had overall poorer OHS scores than non-obese patients (p < 0.001), but improvement of OHS did not differ between obese and non-obese patients (p = 0.198). Conclusion. Obesity is associated with an increased risk of infection following revision THA. Patients with high BMI should be counselled appropriately before surgery

As the American population ages and a trend toward performing total hip arthroplasty (THA) in younger patients continues, the number of Americans undergoing THA is projected to increase over time. The advent of the bundled payment system combined with the current medical utilization climate has placed considerable pressure on surgeons to produce excellent results with early functional recovery and short hospital stays. The US obesity epidemic has transcended into the arthroplasty patient population and surgeons must assess whether obesity is a risk factor for poor outcomes in THA and determine how it should be managed. We performed a recent literature review to determine how obesity impacts outcomes in total hip arthroplasty and what must be done to improve outcomes in the obese arthroplasty patient. Our goal is to answer 3 questions: does obesity increase the complication rate in THA, if obesity matters how obese is too obese, and what must be done to improve outcomes in the obese patient?. Ultimately, obesity has been shown to correlate with increased post-operative complications in THA. The arthroplasty surgeon must optimise the obese patient prior to surgery by identifying associated comorbidities and consider malnutrition screening with counseling. Notice should be taken of the degree of obesity as patients with BMI > 40 have demonstrated much higher complication rates. Strong consideration should be given to avoiding direct anterior approach in the obese patient. Healthy weight loss must be encouraged with appropriate patient counseling and treatment in order to achieve success with THA in obese patients.  

The purpose of this population-based study was to determine the association between morbid obesity and 10-year mortality and complications in patients undergoing primary THA. A cohort study of 22,251 patients, aged 45–74 years old, treated with primary THA between 2002 and 2007 for osteoarthritis, was conducted using Ontario administrative healthcare databases. Patients were followed for 10 years. Risk ratios (RRs) of mortality, reoperation, revision, and dislocation in patients with body mass index (BMI) > 45 kg/m2(morbidly obese patients) compared with BMI ≤45 kg/m2 (non-morbidly obese) were estimated. 3.3% of the cohort (726) was morbidly obese. Morbidly obese patients were younger (mean age 60.6 vs. 63.3, P-value < 0 .001) and more likely to be female (63.9% vs. 52.2%, P-value < 0 .001), compared with non-morbidly obese patients. Morbid obesity was associated with higher 10-year risk of death (RR 1.38, 95% CI 1.18, 1.62). Risks of revision (RR 1.43, 95% CI 0.96, 2.13) and dislocation (RR 2.38, 95% CI 1.38, 4.10) were higher in morbidly obese men, compared with non-morbidly obese men, there were no associations between obesity and revision or dislocation in women. Risk of reoperation was higher in morbidly obese women, compared to non-morbidly obese women (RR 1.60, 95% CI 1.05, 2.40), there was no association between obesity and reoperation in men. Morbidly obese patients undergoing primary THA are at higher risks of long-term mortality and complications. There were differences in complication risk by sex. Results should inform evidence-based perioperative counseling of morbidly obese patients considering THA

Introduction. Given the association of osteoarthritis with obesity, the typical patient requiring total knee arthroplasty (TKA) is often obese. Obesity has been shown to negatively influence outcomes following TKA, as it is associated with increased perioperative complications and poorer clinical and functional outcomes. Achieving proper limb alignment can be more difficult in the obese patient, potentially requiring a longer operation compared to non-obese patients. Patient specific instrumentation (PSI), a technique that utilizes MR- or CT-based customized guides for intraoperative cutting block placement, may offer a more efficient alternative to manual instruments for the obese patient. We hypothesize that the additional information provided by a preoperative MRI or CT may allow surgeons to achieve better alignment in less time compared to manual instrumentation. The purpose of this study was to assess whether PSI offers an improved operation length or limb alignment compared to manual instruments for nonmorbidly and morbidly obese patients. Methods. In this retrospective cohort study, we evaluated 77 PSI TKA and 25 manual TKA performed in obese patients (BMI≥30) between February 2013 and May 2015. During this period, all patients underwent PSI TKA unless unable to undergo MR scanning. All cases were performed by a single experienced surgeon and utilized a single implant system (Zimmer Persona™). PSI cases were performed using the MR-based Zimmer Patient Specific Instrumentation system. Tourniquet times were recorded to determine length of operation. Long-standing radiographs were obtained preoperatively and 4-weeks postoperatively to evaluate limb alignment. Cases were subdivided by nonmorbid obesity (30≤BMI<40) and morbid obesity (BMI≥40) to assess the effect of increasing obesity on outcomes. Results. PSI and manual cohorts were similar with regards to age, gender, and preoperative alignment. Tourniquet time was significantly shorter in the PSI group for nonmorbidly obese patients (PSI 49.8 minutes vs manual 58.3 minutes; p=0.005) (Figure 1). Postoperative mechanical axis was similar between groups for both nonmorbidly obese (PSI 1.8° vs manual 2.9°; p=0.338) and morbidly obese patients (PSI 4.0° vs manual 3.6°; p=0.922). Mechanical axis outliers (greater than 3° neutral), though nonsignificant, were fewer in the PSI group for nonmorbidly obese (PSI 21.8% vs manual 35.3%; p=0.318) and morbidly obese patients (PSI 46.1% vs manual 75.0%; p=0.362). Discussion. We found that PSI significantly shortened operation length for nonmorbidly obese patients compared to manual instruments. Obesity is strongly associated with increased perioperative infection rates, as is prolonged operation length. The decreased operation length achieved with PSI in the nonmorbidly obese patient may as a consequence decrease infection rates, though further study is necessary. Though not statistically significant, PSI showed a trend toward decreasing overall mechanical axis outliers for both nonmorbidly obese and morbidly obese patients. The use of patient specific instrumentation compared to manual instruments has been controversial in the literature. However, patient specific instrumentation may be favorable in the obese patient, offering a shorter operation length and possibly improved alignment

In the USA, 34.9% of adults are currently obese (BMI > 30). Growth in total knee arthroplasty (TKA) is outpacing growth in total hip arthroplasty (THA) largely due to a differential utilization of TKA in overweight patients in the USA. In a recent study, 54.5% of patients reporting to arthroplasty clinics in the USA were obese. From 2006–2010, 61.2% of primary unilateral TKA patients in the USA ACS-NSQIP database were obese. Arthroplasty surgeons are directly affected by the obesity epidemic and need to understand how to safely offer a range of peri-operative care for these patients in order to insure good clinical outcomes. Pre-operative care for the obese patient involves nutritional counseling, weight loss methods, consideration for bariatric surgery, physical therapy, metabolic workup, and diagnosis and management of frequent comorbid conditions (OSA, DM2, HTN, HLD). Obese patients must also be counseled on their increased risk of complications following TKA. In the operating room, several steps can be taken to insure success when performing TKA on obese patients. We recommend performing TKA without the use of a tourniquet in order to prevent fat necrosis and increased pain. The incision is made in 90 degrees of knee flexion, atypically midline proximally and curved distally to the midpoint between the tubercle and the medial edge of the tibia. Care is used to minimise the creation of dead space, and the approach to the knee is an extensile medial parapatellar incision. Closure is in multiple layers. The use of negative pressure dressing following surgery can minimise the early wound drainage that is frequently seen after TKA in obese patients. Post-operative care of the obese patient following TKA involves several unique considerations. Chronic pain and obesity are frequent comorbid conditions and post-operative pain control regimens need to be tailored. Although the physical therapy regimen does not differ in obese patients, obese patients are more likely to be discharged to a rehabilitation facility. Obese patients have a higher rate of all complications compared to healthy weight. All infection and deep infection increased in obese patients in large meta-analysis. Patients with BMI > 35 are 6.7 times more likely to develop infection after TKA. Patients with BMI > 40 have a 3.35 times higher rate of revision for deep infection than those with BMI < 35. The odds ratio for major complications increases dramatically beyond BMI > 45. Although there are a few studies that have demonstrated worse clinical outcome in obese patients following TKA, most studies show no difference in clinical outcomes at short- or long-term follow-up. The arthroplasty surgeon must optimise the obese patient prior to surgery, use intra-operative techniques to maximise success, and anticipate potential problems in the post-operative course in order to achieve success with TKA in obese patients

Obesity and the diseases linked to it such as diabetes have been associated with higher complication rates and increased medical costs following total hip arthroplasty (THA). Due to the rising prevalence of obesity and the adverse impact it has on the development of osteoarthritis, there has been a worldwide surge in the number of obese patients presenting for THA procedures, including those morbidly obese (BMI > 40) and those who are super-obese (BMI > 50). The Reward. When THA is successful (as is true for the majority of morbidly obese patients) the operation is just as dramatically effective as it is for other patients. Excellent pain relief and dramatically improved function is the result, even though obese patients generally achieve a lower overall level of function than non-obese patients. Morbidly obese patients with a successful THA and without early complications are some of the most grateful of patients. This is especially true if they have been denied surgery for prolonged periods due to their weight and have had to bear severe joint changes and symptoms during a long period of time leading up to arthroplasty. The Risks. There is a nonlinear increase in complications, reoperations, and especially infection with increasing BMI that begins between a BMI of 25 to 30, and rises thereafter with a relative inflection point in some incidence curves for complications at around a BMI of 40. This has caused some surgeons to suggest a BMI of 40 as an upper limit for elective hip arthroplasty. Risks continue to rise after a BMI of 40 and when the BMI is over 50, in our series 52% of patients had at least one complication. Of these 24% had at least one major complication and 33% at least one minor complication with some suffering more than one complication overall. These data make it reasonable to ask whether the outcomes in some morbidly obese patients might be improved by weight loss, bariatric surgical intervention and other measures aimed at optimizing the multiple companion comorbidities and medical conditions (such as diabetes) that often accompany excess weight. Unfortunately there has been limited information to date on the best means for optimizing of these patients, and as important the effectiveness of these interventions, so that the timing and performance of the eventual arthroplasty procedures might have the highest possible success rate. The Costs. The adverse impact of obesity on medical resource utilization and costs associated with THA has been well documented, Due to longer initial length of stay, greater resource utilization, higher early complication rates and any readmissions and reoperations the costs for even a single individual patient can climb dramatically. In a review of data on primary THA patients from our institution, even after adjusting for age, sex, type of surgery, and other comorbidities, for every 5 unit increase in BMI beyond 30 kg/m2 there was an associated $500 higher cost of hospitalization and an increase of $900 in 90-day total costs (p=0.0001). The Future. The numbers of morbidly obese patients with severe osteoarthritis presenting for possible THA will only continue to increase in the years ahead. Comprehensive multidisciplinary programs are urgently needed to better manage obese patients with weight reduction options, optimization of medical comorbidities, and treatment of any associated issues, such as protein malnutrition. When end-stage joint changes and symptoms occur we must have such help to maximise the benefit and reduce the complications of hip arthroplasty in this high risk patient population

Obesity is a leading public health concern and it is increasing in prevalence over the last 20 years. Obesity prevalence has doubled in adults and tripled in adolescents. The United States is the leading country in terms of percent obesity. Most alarming is the fact that the fastest growing rates of obesity are in the highest BMI groups. The issue of obesity is a particular concern to arthroplasty surgeons since there is an association between the increasing incidence of obesity and the increasing rate of joint replacement. Also of concern is that obese patients tend to be younger and complication rates and revision rates are higher in young patients which is only compounded by the presence of obesity. The risk of virtually every major complication is substantially higher in obese patients. Of concern, however, is a recent study indicating that bariatric surgery with successful weight loss does not necessarily decrease the complication rate. Obesity is also associated with substantially higher costs. There is some evidence that obesity doesn't necessarily affect implant survival. There is also evidence that the clinical outcomes may not be substantially compromised by the presence of obesity. Based on data from studies such as this, some centers have stated that it is difficult to justify withholding surgery based on BMI alone. The data on weight loss following surgery indicates the vast majority of patients did not lose weight following joint replacement. In one study a higher proportion of patients gained weight than lost weight