Go Big or Go Home: Obesity and Total Joint Arthroplasty

[Influence of obesity on midterm outcome after primary hip and knee arthroplasty in Germany : Analysis from the EPRD]

OBJECTIVES

To determine the influence of obesity on revision rates and mortality after primary elective hip and knee arthroplasty in Germany.

MATERIALS AND METHODS

In the German Arthroplasty Registry (EPRD) there were 403,073 elective total hip arthroplasties (THA), 320,913 bicondylar total knee arthroplasties (TKA) and 48,480 unicondylar knee arthroplasties (UKA) with valid BMI available for analysis. Cumulative revision rates and 1‑year mortality was calculated for BMI groups.

RESULTS

There were increased revision rates with increasing BMI, most distinctive for septic revisions in THA during the first year after surgery (non-obese 0.7%, obesity grade 1 1.3%, grade 2 2.1%, grade 3 4.2%). In TKA and UKA this increase was generally less pronounced. Age- and gender-standardized mortality was lower than expected in most groups, but also increasing with increasing BMI.

CONCLUSION

The risk for revisions in obese patients is more distinctive in hip arthroplasty than in knee arthroplasty and is especially high in morbidly obese patients (BMI ≥ 40 kg/m2). Nonetheless, this risk may be acceptable for affected patients. Therefore, the possible benefits and risks of an arthroplasty should be weighed against each other and individually discussed with the patient.

[Perioperative management of obese patients undergoing elective hip and knee arthroplasty]

INTRODUCTION

Obesity is a worldwide growing health crisis, affecting younger and younger age groups and posing new challenges for arthroplasty. Due to increased complication rates in this population, many authors are of the opinion that in patients with a body mass index (BMI) of over 40, the problems outweigh the benefits of surgery and that surgery should be postponed until significant weight reduction has been achieved.

MATERIALS AND METHODS

A systematic review of electronic databases (PubMed, Embase, Web of Science and the Cochrane Library) was performed. 49 relevant articles were analyzed. Pre-defined questions were answered based on the literature. The level of evidence for the recommendation was defined in a consensus meeting.

RESULTS

Obese patients with a BMI ≥ 30 have an up to threefold increased perioperative risk, particularly for infections and mechanical complications. In addition, surgery in obese patients is technically demanding, which results in a higher risk of implant malpositioning. Despite these risks, obese patients benefit from surgery in a similar way compared to normal-weight patients, showing comparable improvements in function and quality of life. Preoperative weight loss can reduce the risk but should be long-term to avoid negative metabolic effects. Bariatric surgery and drug therapies can help, but their effects on perioperative risk are unclear. Besides the BMI, careful diagnosis and treatment of comorbidities is crucial.

CONCLUSION

Obese patients benefit from arthroplasty in a similar way to normal-weight patients but have a higher risk of complications, particularly infection. Prior to joint replacement, patients with a BMI of 40 or more should undergo dietary counselling and weight reduction; their metabolic status should be checked, as malnutrition can increase the risk. If weight reduction is not achieved despite these measures, the operation can be performed with increased risks, whereby the patient should be fully informed and involved in the decision-making process.

Effects of elevated body mass index on the success of total knee and total hip arthroplasty: a comprehensive overview

INTRODUCTION

The average body mass index (BMI) in the United States has tripled over the last five decades despite concerted population-based efforts for weight management. Elevated BMI and, in particular, obesity are risk factors for osteoarthritis. This trend has led to increased demands for total knee (TKA) and total hip arthroplasty (THA), necessitating an in-depth understanding of how elevated BMI impacts TKA and THA.

AREAS COVERED

This paper reviews the literature investigating the effects of elevated BMI, primarily obesity, on TKA and THA, focusing on preoperative, intraoperative, and postoperative considerations. It describes the associated risks, economic implications, and ethical considerations of patients with high BMIs undergoing TKA or THA. To ensure all relevant literature was included, Ovid Medline and Google Scholar databases were searched for the following terms, 'body mass index,' 'obesity,' 'knee,' 'hip,' and 'arthroplasty' for articles published from January 2019 through July 2024.

EXPERT OPINION

Despite the challenges of high BMI in TKA and THA, a deeper understanding of obesity as a chronic illness, coupled with advances in surgical techniques, can improve patient outcomes. A multidisciplinary approach and further research will optimize the care of patients with elevated BMIs undergoing total joint arthroplasty (TJA).

Should Body Mass Index Be Considered a Hard Stop for Total Joint Replacement?: An Ethical Dilemma

Total joint arthroplasty (TJA) is one of the most common surgeries performed in the United States and is a durable and effective option in managing osteoarthritis of the hip and knee. Recent research regarding the procedure has focused on preoperative optimization and weight loss in particular. Obesity has been shown in prior studies to increase risks associated with TJA, and, as a result, debate has focused on whether a body mass index (BMI) cutoff is a prudent tool for preoperative optimization. This article discusses the ethical dilemma of instituting a BMI cutoff and reviews current literature regarding the topic.

Preventive strategies to reduce the rate of periprosthetic infections in total joint arthroplasty; a comprehensive review

The increasing frequency of total hip (THA) and knee arthroplasties (TKA) is marred by the rise in periprosthetic joint infections (PJIs) and surgical site infections (SSIs), with PJIs incurring costs over $1.62 billion as of 2020 and individual case management averaging $90,000. SSIs additionally burden the U.S. healthcare economy with billions in expenses annually. PJI prevalence in primary THA and TKA ranges from 0.5% to 2.4%, spiking to 20% in revisions and representing 25% of TKA revision causes. Projections estimate up to 270,000 annual PJI cases by 2030. Often caused by gram-positive bacteria, particularly methicillin-resistant staphylococci, these infections demand preventive measures. This review dissects PJI prevention across preoperative, intraoperative, and perioperative phases, aligning with evidence-based CDC and WHO guidelines. Preoperative measures include managing diabetes, obesity, tobacco use, Staphylococcus aureus screening and nasal decolonization, nutritional optimization, and management of inflammatory arthropathies. Intraoperatively, antibiotic prophylaxis, skin preparation, operative room environmental controls, surgical technique precision, and irrigation options are scrutinized. Perioperative concerns focus on anticoagulation, blood management, and infection risk mitigation. Integrating these strategies promotes a patient-centric care model, aiming to reduce PJI incidence, improve patient outcomes, and increase care cost-effectiveness in joint arthroplasty.

Sleeve gastrectomy prior to primary total hip and total knee arthroplasty is associated with increased risk of early complications

Aims

The purpose of this study was to determine the association between prior sleeve gastrectomy in patients undergoing primary total hip and knee arthroplasty, and 90-day complications, incidence of revision arthroplasty, and patient-reported outcome scores at final follow-up.

Methods

This is a retrospective, single-centre analysis. Patients undergoing primary hip or knee arthroplasty with a prior sleeve gastrectomy were eligible for inclusion (n = 80 patients). A morbidly obese control group was established from the same institutional registry using a 1:2 match, for cases:controls with arthroplasty based on propensity score using age, sex, pre-sleeve gastrectomy BMI, Current Procedural Terminology code to identify anatomical location, and presurgical haemoglobin A1C. Outcomes included 90-day complications, incidence of revision arthroplasty, and patient-reported outcome scores at final follow-up. Multivariable logistic regressions evaluated associations of underlying preoperative demographic and treatment characteristics with outcomes.

Results

Complications within 90 days of surgery were increased in the sleeve gastrectomy group relative to the obese control group after controlling for underlying preoperative demographic characteristics (odds ratio (OR) 4.00 (95% CI 1.14 to 13.9); p = 0.030). Postoperative revisions were similar in the sleeve gastrectomy group relative to the obese control group after controlling for underlying preoperative demographic characteristics (OR 17.8 (95% CI 0.64 to 494.3); p = 0.090). Patient-Reported Outcomes Measurement Information System (PROMIS) depression decreased by a greater amount from pre- to postoperative in the obese controls relative to the sleeve gastrectomy group (OR 4.04 (95% CI 0.06 to 8.02); p = 0.047). PROMIS pain interference and physical function change from pre- to postoperative was not associated with sleeve gastrectomy status.

Conclusion

We found a higher rate of complications at 90 days in patients who underwent sleeve gastrectomy prior to primary hip or knee arthroplasty relative to a matched, obese control population. Prosthetic revision rates were similar between the two groups, while improvements in PROMIS depression scores were larger in the obese cohort. This study suggests that sleeve gastrectomy to achieve preoperative weight loss prior to arthroplasty surgery may not mitigate early complication risks in obese patient populations.

Obesity Severity Does Not Associate With Rate, Timing, or Invasiveness of Early Reinterventions After Total Knee Arthroplasty

BACKGROUND

The use of body mass index (BMI) cutoff values has been suggested for proceeding with total knee arthroplasty (TKA) in obese patients. However, the relationship between obesity severity and early reoperations after TKA is poorly defined. This study evaluated whether increased World Health Organization (WHO) obesity class was associated with risk, severity, and timing of reintervention within one year after TKA.

METHODS

There were 8,674 patients from our institution who had a BMI ≥ 30 and underwent unilateral TKA for primary osteoarthritis between 2016 and 2021. Patients were grouped by WHO obesity class: 4,456 class I (51.5%), 2,527 class II (29.2%), and 1,677 class III (19.4%). A chart review was performed to determine patient characteristics and identify patients who underwent any closed or open reintervention requiring anesthesia within the first postoperative year. Regression analyses were performed to identify variables associated with increased odds ratios (ORs) for requiring a reintervention, its timing, and invasiveness.

RESULTS

There were 158 patients (1.8%) who required at least one reintervention, and 15 patients (0.2%) required at least 2 reinterventions. Reintervention rates for obesity classes I, II, and III were 1.8% (n = 81), 2.0% (n = 51), and 1.4% (n = 23), respectively. There were 65 closed procedures (41.1%), 47 minor procedures (29.7%), 34 open with or without liner exchange (21.5%), and 12 revisions with component exchange (7.6%). Obesity class was not associated with reintervention rate (P = .3), timing (P = .36), or invasiveness (P = .93). Diabetes (odds ratio [OR] = 2.47; P = .008) was associated with a need for reintervention. Non-Caucasian race (OR = 1.7; P = .01) and Charlson comorbidity index (OR = 2.1; P = .008) were associated with earlier reintervention. No factors were associated with the invasiveness of reintervention.

CONCLUSIONS

The WHO obesity class did not associate with rate, timing, or invasiveness of reintervention after TKA in obese patients. These findings suggest that policies that restrict the indication for elective TKA based only on a BMI limit have limited efficacy in reducing early reintervention after TKA in obese patients.

LEVEL OF EVIDENCE

III.

Preoperative and Postoperative Weight Change has Minimal Influence on Health Care Utilization and Patient-Reported Outcomes Following Total Knee Arthroplasty

As obesity becomes more prevalent, more patients are at risk of lower extremity osteoarthritis and subsequent total knee arthroplasty (TKA). This study aimed to test (1) the association of preoperative weight change with health care utilization and (2) the association of pre- and postoperative weight changes with failure to achieve satisfaction and minimal clinically important difference (MCID) in Knee injury and Osteoarthritis Outcome Score for pain (KOOS-Pain) and function (KOOS-PS) 1 year after TKA. Prospectively collected monocentric data on patients who underwent primary TKA were retrospectively reviewed. Multivariable logistic regression assessed the influence of BMI and weight change on outcomes while controlling for confounding variables. Outcomes included prolonged length of stay (LOS >3 days), nonhome discharge, 90-day readmission rate, satisfaction, and achievement of MCID for KOOS-Pain and KOOS-PS. Preoperative weight change had no impact on prolonged LOS (gain, p = 0.173; loss, p = 0.599). Preoperative weight loss was associated with increased risk of nonhome discharge (odds ratio [OR]: 1.47, p = 0.003). There was also increased risk of 90-day readmission with preoperative weight gain (OR: 1.27, p = 0.047) and decreased risk with weight loss (OR: 0.73, p = 0.033). There was increased risk of nonhome discharge with obesity class II (OR: 1.6, p = 0.016) and III (OR: 2.21, p < 0.001). Weight change was not associated with failure to achieve satisfaction, MCID in KOOS-Pain, or MCID in KOOS-PS. Obesity class III patients had decreased risk of failure to reach MCID in KOOS-Pain (OR: 0.43, p = 0.005) and KOOS-PS (OR: 0.7, p = 0.007). Overall, pre- and postoperative weight change has little impact on the achievement of satisfaction and clinically relevant differences in pain and function at 1 year. However, preoperative weight gain was associated with a higher risk of 90-day readmissions after TKA. Furthermore, patients categorized in Class III obesity were at increased risk of nonhome discharge but experienced a greater likelihood of achieving MCID in KOOS-Pain and KOOS-PS. Our results raise awareness of the dangers of using weight changes and BMI alone as a measure of TKA eligibility.

Evidence-based and Patient-centered Indication for Knee Arthroplasty - Update of the Guideline

Knee arthroplasty is one of the most frequently performed operations in Germany, with approximately 170000 procedures per year. It is therefore essential that physicians should adhere to an appropriate, and patient-centered indication process. The updated guideline indication criteria for knee arthroplasty (EKIT-Knee) contain recommendations, which are based on current evidence and agreed upon by a broad consensus panel. For practical use, the checklist has also been updated.For this guideline update, a systematic literature research was conducted in order to analyse (inter-)national guidelines and systematic reviews focusing on osteoarthritis of the knee and knee arthroplasty, to answer clinically relevant questions on diagnostic, predictors of outcome, risk factors and contraindications.Knee arthroplasty should solely be performed in patients with radiologically proven moderate or severe osteoarthritis of the knee (Kellgren-Lawrence grade 3 or 4), after previous non-surgical treatment for at least three months, in patients with high subjective burden with regard to knee-related complaints and after exclusion of possible contraindications (infection, comorbidities, BMI ≥ 40 kg/m2). Modifiable risk factors (such as smoking, diabetes mellitus, anaemia) should be addressed and optimised in advance. After meeting current guideline indications, a shared decision-making process between patients and surgeons is recommended, in order to maintain high quality surgical management of patients with osteoarthritis of the knee.The update of the S2k-guideline was expanded to include unicondylar knee arthroplasty, the preoperative optimisation of modifiable risk factors was added and the main indication criteria were specified.