Practice Patterns in Body Mass Index Optimization Among US Arthroplasty Surgeons: Results of a National American Association of Hip and Knee Surgeons Survey

Abstract

Introduction: As total hip arthroplasty and total knee arthroplasty procedures are increasingly performed on younger patients with obesity, the optimal approach to preoperative weight management remains undefined. This study explores national trends among US arthroplasty surgeons regarding body mass index (BMI) cutoffs, weight optimization strategies, and weight loss medication usage.

Methods: A 28-question national survey was distributed through e-mail to members of the American Association of Hip and Knee Surgeons and shared on professional social media platforms (Facebook, ResearchGate, and LinkedIn) between January 1 and August 5, 2024.

Results: Regarding arthroplasty reconstruction fellowship training, 82.58% (441/534) of respondents were fellowship trained, 11.42% (61/534) were not fellowship trained, and 5.99% (32/534) trained in other specialties. In terms of BMI optimization strategies, 82.84% (n = 444/536) recommended structured diet and exercise programs, 77.99% (n = 418/536) recommended dietitian or weight loss specialist programs, and 52.61% (n = 282/536) advocated for bariatric surgery. For total hip arthroplasty, 45.13% of surgeons used a BMI cutoff <40 kg/m2 (n = 241/534), followed by 23.97% advocating for no strict cutoff (n = 128/534). For total knee arthroplasty, 41.65% reported using a cutoff of <40 kg/m2 (n = 222/533), with 24.39% (n = 130/533) reporting no strict BMI cutoff. In addition, 27.62% (n = 58/210) reported that their patients used weight loss medications such as GLP-1 agonists. Notably, 68.0% (n = 356/526) of surgeons allowed up to 1 to 2 years for BMI optimization before surgery.

Conclusion: Although many arthroplasty surgeons use BMI cutoffs, many accommodate patients through nonsurgical interventions to facilitate weight loss. These findings indicate that many respondents report a multidisciplinary approach to preoperative BMI optimization.

Figure 1

Pie chart showing demographic characteristics of arthroplasty surgeons surveyed. Top left: Fellowship training status (n = 534), with the darkest segment denoting fellowship trained in adult reconstruction (82.6%), intermediate shading for not fellowship trained (11.4%), and the lightest for fellowship-trained in other specialties (6.0%). Top right: Practice setting (n = 534), with darker segments for hospital employed (27.0%) and small private practice (27.0%), moderate shading for academic medical centers (21.3%) and large multispecialty groups (19.7%), and the lightest for other settings (5.1%). Bottom left: Years in practice (n = 536), with shading from darkest to lightest corresponding to ≥20 years (36.4%), <20 years (22.2%), <10 years (17.4%), <5 years (20.0%), and <1 year (4.1%). Bottom right: Availability of a formal weight loss program (n = 206), with lighter shading representing no program (59.7%) and darker shading for formal programs (40.3%).

Figure 2

Bar chart showing distribution of reported body mass index (BMI) cutoffs for total hip arthroplasty (THA) and total knee arthroplasty (TKA). Bar chart of surgeon-reported BMI thresholds for surgical candidacy. Lavender bars represent THA and violet bars represent TKA.

Figure 3

Bar chart showing recommended strategies for BMI optimization before arthroplasty. Survey responses (n = 210) reflect endorsement of weight loss interventions. Darker bars represent the most frequently recommended approaches: diet/exercise programs (82.8%) and referral to a dietician or weight loss specialist (78.0%). Intermediate and lighter bars represent self-directed weight loss (59.7%), surgical weight loss (52.6%), multimodal approach (73.7%), no definitive program (7.5%), and other strategies (4.5%).

Figure 4

Bar chart showing recommended duration of preoperative BMI optimization. Bar graph displaying preferred optimization timeframes (n = 210) and percentage of respondents. The darkest bar corresponds to <1 year (41.7%), followed by < 2 years (25.8%), <6 months (21.3%), no optimization required (8.7%), and <3 months (2.3%), shown in progressively lighter shades.

Figure 5

Bar chart showing use and route of weight loss medications. Left panel (n = 210): Survey responses on the use of pharmacologic weight loss agents. The darker bar indicates respondents who recommend medications (27.6%); the lighter bar indicates those who do not (72.4%). Right panel (n = 153): Reported routes of administration among those who recommend weight loss medications: darkest bar indicates oral (10.5%), intermediate bar indicates injectable (26.8%), and lightest bar indicates other or unspecified (62.8%).