The purpose of this study was to examine the complications and outcomes of total hip replacement (THR) in super-obese patients (body mass index (BMI) > 50 kg/m. 2. ) compared with class I obese (BMI 30 to 34.9 kg/m. 2. ) and normal-weight patients (BMI 18.5 to 24.9 kg/m. 2. ), as defined by the World Health Organization. A total of 39 THRs were performed in 30 super-obese patients with a mean age of 53 years (31 to 72), who were followed for a mean of 4.2 years (2.0 to 11.7). This group was matched with two cohorts of normal-weight and class I obese patients, each comprising 39 THRs in 39 patients. Statistical analysis was performed to determine differences among these groups with respect to complications and satisfaction based on the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, the Harris hip score (HHS) and the Short-Form (SF)-12 questionnaire. Super-obese patients experienced significantly longer hospital stays and higher rates of major complications and readmissions than normal-weight and class I obese patients. Although super-obese patients demonstrated reduced pre-operative and post-operative satisfaction scores, there was no significant difference in improvement, or change in the score, with respect to HHS or the WOMAC osteoarthritis index. Super-obese patients obtain similar satisfaction outcomes as class I obese and normal-weight patients with respect to improvement in their scores. However, they experience a significant increase in length of hospital stay and major complication and readmission rates. Cite this article: Bone Joint J 2013;95-B:758–63

Introduction. The obesity epidemic is a growing problem and must be considered with the projected increased demand for total hip arthroplasty (THA). Previous studies have reported increased complication rates after THA in the obese population, which has led to hesitation in offering surgery to this population. Moreover, some insurers are denying coverage for morbidly obese patients. While many consider obesity a “modifiable” risk factor, very few patients with advanced osteoarthritis have successfully lost substantial weight. The experience of centers that utilize systematic preoperative risk stratification tools and standardized postoperative total joint pathways may be underrepresented in prior studies. The aim of this study is to describe one surgeon's experience performing THA in morbidly and super-obese patient populations using an institutional preoperative Risk Stratification Tool (RST) and total joints pathway. Methods. We conducted a retrospective review of patients undergoing primary THA between May 2014 and December 2017 performed by a single surgeon at a tertiary care referral center. All patients were assessed preoperatively using an institutional RST and had a minimum of 90-day postoperative follow up. Patients were stratified by body mass index (BMI, kg/m. 2. ): non-obese (BMI < 30), obese (30–34), severely obese (35–39), morbidly obese (40–44), and super-obese (≥ 45). Primary outcomes were inpatient and 90-day complications. Continuous and binary parameters were analyzed by Kruskal-Wallis and Fisher exact tests. Logistic regression was additionally utilized to evaluate outcomes by BMI cohort. Results. A consecutive series of 368 patients met inclusion criteria across all BMI cohorts. There was significant variation with respect to age (P=0.001), BMI (P<0.001), diabetes (P=0.008), ASA class (P<0.001), and anesthesia type (P=0.003) (Table 1). Variation among BMI cohorts was also identified for several operative and postoperative parameters, including longer operative and in-room time and greater length of stay (P<0.001) (Table 2). Compared to non-obese patients, super-obese patients had 20.1 greater odds of return to OR within 90 days for superficial surgical site infection (SSI) or prolonged round drainage (P=0.008) (Table 3). Notably, morbidly and super-obese patients were not at significantly increased risk for inpatient intensive care unit (ICU) transfer, blood transfusion, 90-day emergency room visit, or 90-day readmission compared to their non-obese counterparts. For patients in whom 1-year follow-up was available, these differences between BMI cohorts remained insignificant. Conclusions. Patients with BMI>40 are more likely than non-obese patients to have increased postoperative rehabilitation needs but are not at increased risk for in-hospital complications. Super-obese patients have greater risk of superficial SSI or prolonged wound drainage than non-obese patients but are not at increased risk for revision or deep infection in any cohort. Use of a preoperative RST may help to mitigate postoperative complications and readmissions previously associated with morbid and super-obesity. We conclude that THA can be safely performed in super-obese patients and therefore care should not be denied to this population. Summary sentence. Total hip arthroplasty (THA) can be safely performed in morbidly and super-obese patients with the use of a preoperative risk stratification tool (RST) and total joints pathway. For any tables or figures, please contact the authors directly

Introduction. The purpose of this study is to estimate the cost-effectiveness of performing total hip arthroplasty (THA) versus nonoperative management (NM) in non-obese (BMI 18.5–24.9), overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–49.9), and super-obese (50+) patients. Methods. We constructed a state-transition Markov model to compare the cost-utility of THA and NM in the six above-mentioned BMI groups over a 15-year time period. Model parameters for transition probability (i.e. risk of revision, re-revision, death), utility, and costs (inflation adjusted to 2017 US dollars) were estimated from the literature. Direct medical costs of managing hip arthritis were accounted in the model. Indirect societal costs were not included. A 3% annual discount rate was used for costs and utilities. The primary outcome was the incremental cost-effectiveness ratio (ICER) of THA versus NM. One-way and Monte Carlo probabilistic sensitivity analysis of the model parameters were performed to determine the robustness of the model. Results. Over the 15-year time period, the ICERs for THA versus NM were: normal-weight ($6,043/QALY), overweight ($5,770/QALY), obese ($5,425/QALY), severely-obese ($7,382/QALY), morbidly-obese ($8,338/QALY), and super-obese ($16,651/QALY). The two highest BMI groups had higher incremental QALYs and incremental costs. The probabilistic sensitivity analysis suggests that THA would be cost-effective in 100% of the normal, overweight, obese, severely-obese, and morbidly-obese simulations, and 99.95% of super-obese simulations at an ICER threshold of $50,000/QALY. Conclusion. Even at a willingness-to-pay threshold of $50,000/QALY, which is considered low for the United States, our model showed that THA would be cost effective for all obesity levels. Therefore, invoking BMI cut-offs for THA may lead to unjustifiable loss of healthcare access for obese patients with end-stage hip osteoarthritis

The purpose of this study is to compare 90-day costs and outcomes for primary total hip arthroplasty (THA) patients between a non-obese (BMI 18.5–24.9) versus overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–44.9), and super-obese (45+) cohorts. We conducted a retrospective review of a prospective institutional database of primary THA patients from 2006–2013, including patients with a minimum of three-year follow-up. Thirty-three super-obese patients were identified, and the other five cohorts were randomly selected in a 2:1 ratio (total n = 363). Demographics, 90-day outcomes (costs, reoperations, and readmissions), and outcomes after three years (revisions and change scores for SF12, HHS, and WOMAC) were collected. Costs were determined using unit costs from our institutional administrative data for all in-hospital resource utilization. Comparisons between the non-obese and other groups were made with Kruskal-Wallis tests for non-normal data and chi-square and Fisher's exact test for categorical data. The 90-day costs in the morbidly-obese ($13,134 ± 7,250 mean ± standard deviation, p <0.01) and super-obese ($15,604 ± 6,783, p <0.01) cohorts were statistically significantly greater than the non-obese cohorts ($10,315 ± 1,848). Only the super-obese cohort had statistically greater 90-day reoperation and readmission rates than the non-obese cohort (18.2% vs 0%, p <0.01 and 21.2% vs 4.5%, p=0.02, respectively). In addition, reoperations and septic revisions after 3 years were greater in the super-obese cohort compared to the non-obese cohort 21.2% vs 3.0% (p = 0.01), and 18.2% vs 1.5% (p= 0.01), respectively. There were no other statistical differences between the other cohorts with the non-obese cohort at 90-days or after 3 years. Improvements in SF12, HHS, and WOMAC were comparable in all cohorts. The 90-day costs of a primary total hip arthroplasty for morbidly-obese (BMI 40–44.9) and super-obese (BMI>45) are significantly greater than for non-obese patients, yet these patients have comparable improvements in outcome scores. Health care policies, when based purely on the economic impact of health care delivery, may place morbidly-obese and super-obese patients at risk of losing arthroplasty care, thereby denying them access to the comparable quality of life improvements

The August 2013 Hip & Pelvis Roundup. 360 . looks at: are we getting it right first time?; tantalum augments in revision hip surgery; lower wear in dual mobility?; changing faces changes outcomes; synovial fluid aspiration in MOM hips; taper disease: the new epidemic of hip surgery; the super-obese and THR; and whether well fixed stems can remain in infected hips

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

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 total joint arthroplasty (TJA) and determine how it should be managed in order to insure good clinical outcomes. In the United States, 34.9% of adults are currently obese (BMI > 30). 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. 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 pre-operative screening and management is essential in reducing complications. Although weight loss is important, our 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 optimisation to ensure successful treatment in obese TJA 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 global epidemic of 2.1 billion people and a well known cause of osteoarthritis. Joint replacement in the obese attracts more complications, poorer outcomes and higher revision rates. It is a reversible condition and the fundamental principles of dealing with reversible medical conditions prior to elective total joint replacement should apply to obesity. The dilemma for orthopaedic surgeons is when to offer surgery in the face of a reversible condition, which if treated may obviate joint replacement and reduce the risk and severity of obesity related disease in both the medical arena and the field of orthopaedics.

Modern healthcare contracting is shifting the responsibility for improving quality, enhancing community health and controlling the total cost of care for patient populations from payers to providers. Population-based contracting involves capitated risk taken across an entire population, such that any included services within the contract are paid for by the risk-bearing entity throughout the term of the agreement. Under such contracts, a risk-bearing entity, which may be a provider group, a hospital or another payer, administers the contract and assumes risk for contractually defined services. These contracts can be structured in various ways, from professional fee capitation to full global per member per month diagnosis-based risk. The entity contracting with the payer must have downstream network contracts to provide the care and facilities that it has agreed to provide. Population health is a very powerful model to reduce waste and costs. It requires a deep understanding of the nuances of such contracting and the appropriate infrastructure to manage both networks and risk.

Cite this article: Bone Joint J 2017;99-B:1431–4.