Change in Body Mass Index after Simultaneous Bilateral Total Knee Arthroplasty: Risk Factors and Its Influence on Functional Outcomes

Do Overall Weight, Body Mass Index, or Clinically Meaningful Weight Changes Occur After Total Joint Arthroplasty? A Meta-Analysis of 60,837 Patients

BACKGROUND

Total joint arthroplasty (TJA) is well-recognized for improving quality of life and functional outcomes of patients with osteoarthritis; however, TJA's impact on body weight remains unclear. Recent trends have demonstrated a shift among TJA patients, such that patients who have higher body mass indices (BMIs) are undergoing this common surgery. Given this trend, it is critical to characterize the impact TJA has on body weight or BMI. This meta-analysis aimed to quantitatively assess whether patients lose, gain, or maintain body weight or BMI after TJA.

METHODS

This study followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials databases were queried from inception through July 2022. The included studies: (1) reported on weight or BMI after elective, primary total hip arthroplasty (THA) or total knee arthroplasty (TKA); and (2) weight or BMI change was deemed to be associated with THA or TKA. The excluded studies: (1) included weight or BMI interventions; and (2) reported on unicompartmental, partial, or revision arthroplasty or joint arthroscopy. Meta-analyses for weight change, BMI change, and proportion of patients achieving clinically significant change were performed using random-effects models. Factors associated with clinically significant change were systematically reported. A total of 60,837 patients from 39 studies were included.

RESULTS

No significant differences existed between preoperative and postoperative weights (P = 1.0; P = 0.28) or BMIs (P = 1.0; P = 1.0) after THA or TKA, respectively. Overall, 66% of THA patients (P < 0.01) and 65% of TKA patients (P < 0.01) did not experience clinically significant weight change.

CONCLUSIONS

Among a TJA cohort, two-thirds of the patients maintained their preoperative body weight or BMI after surgery. With these results, orthopaedic surgeons can better manage patient expectations of TJA.

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.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

The Association of Total Knee Arthroplasty With Weight Loss in the Look AHEAD (Action for Health in Diabetes) Clinical Trial

BACKGROUND

Patients who have obesity seldom lose weight after total knee arthroplasty (TKA). The Look AHEAD (Action for Health in Diabetes) trial randomized patients with type 2 diabetes who were overweight or had obesity to a 10-year intensive lifestyle intervention (ILI) or diabetes support and education (DSE).

METHODS

Of the total 5,145 participants enrolled who had a median 14-year follow-up, a subset of 4,624 met inclusion criteria. The ILI aimed at achieving and maintaining a 7% weight loss and included weekly counseling the first 6 months, with decreasing frequency thereafter. This secondary analysis was undertaken to determine what effects a TKA had on patients participating in a known successful weight loss program and specifically if there was a negative impact on weight loss or their Physical Component Score.

RESULTS

The analysis suggests that the ILI remained effective for maintaining or losing weight after TKA. Participants in ILI had significantly greater percent weight loss than those in DSE both before and after TKA (ILI-DSE before TKA: -3.6% (-5.0, -2.3); after TKA: -3.7% (-4.1, -3.3); both P < .0001). When comparing percent weight loss before to after TKA, there was no significant difference within either the DSE or ILI group (least square means ± standard error ILI: -0.36% ± 0.3, P = .21; DSE: -0.41% ± 0.29, P = .16). Physical Component Scores improved after TKA (P < .001), but no difference was found between TKA ILI and DSE groups before or after surgery.

CONCLUSION

Participants who had a TKA did not have an altered ability to adhere to intervention goals to maintain weight loss or obtain further weight loss. The data suggest patients who have obesity can lose weight after TKA on a weight loss program.