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