Weight change following knee and hip joint arthroplasty-a six-month prospective study of adults with osteoarthritis

A Longitudinal Analysis of Weight Changes before and after Total Knee Arthroplasty: Weight Trends, Patterns, and Predictors

Longitudinal data on patient trends in body mass index (BMI) and the proportion that gains or loses significant weight before and after total knee arthroplasty (TKA) are scarce. This study aimed to observe patients longitudinally for a 2-year period and determine (1) clinically significant BMI changes during the 1 year before and 1 year after TKA and (2) identify factors associated with clinically significant weight changes.A prospective cohort of 5,388 patients who underwent primary TKA at a tertiary health care institution between January 2016 and December 2019 was analyzed. The outcome of interests was clinically significant weight changes, defined as a ≥5% change in BMI, during the 1-year preoperative and postoperative periods, respectively. Patient-specific variables and demographics were assessed as potential predictors of weight change using multinomial logistic regression.Overall, 47% had a stable weight throughout the study period (preoperative: 17% gained, 15% lost weight; postoperative: 19% gained, 16% lost weight). Patients who were older (odds ratio [OR] = 0.95), men (OR = 0.47), overweight (OR = 0.36), and Obese Class III (OR = 0.06) were less likely to gain weight preoperatively. Preoperative weight loss was associated with postoperative weight gain 1 year after TKA (OR = 3.03). Preoperative weight gain was associated with postoperative weight loss 1 year after TKA (OR = 3.16).Most patients maintained a stable weight before and after TKA. Weight changes during the 1 year before TKA were strongly associated with reciprocal rebounds in BMI postoperatively, emphasizing the importance of ongoing weight management during TKA and the recognition of patients at higher risk for weight gain.Level of evidence II (prospective cohort study).

Increase in Postoperative Body Mass Index in Patients After Total Knee Arthroplasty

Objectives The aim of this is to investigate the changes in body mass index (BMI) following knee arthroplasty and to evaluate their impact on patient-reported outcomes and functional evaluations. Methods This observational study included 90 patients who underwent total knee arthroplasty (TKA) and were followed up for a median period of 2.6 years. BMI measurements were recorded before and after surgery, and patient-reported outcomes and functional evaluations were assessed using standardized scales and tests. Results Following TKA, BMI increased statistically significantly (Wilcoxon signed-rank test, p < 0.000). In addition, half of the patients experienced an increase in BMI, with 32% moving up in their BMI category. However, there were no clinically significant differences in patient-reported outcomes or functional evaluations between the group that gained BMI and the group that maintained or lost BMI. Conclusion This study reveals that patients tend to have increased BMI following TKA. However, these BMI changes do not significantly impact patient-reported outcomes or functional evaluations. It underscores the importance of patient education regarding healthy lifestyle habits, including diet and physical activity, to address postoperative weight gain effectively.

Total knee arthroplasty and bariatric surgery: change in BMI and risk of revision depending on sequence of surgery

BACKGROUND

Patients with obesity have a higher risk of complications after total knee arthroplasty (TKA). We investigated the change in weight 1 and 2 years post-Bariatric Surgery (BS) in patients that had undergone both TKA and BS as well as the risk of revision after TKA based on if BS was performed before or after the TKA.

METHODS

Patients who had undergone BS within 2 years before or after TKA were identified from the Scandinavian Obesity Surgery Register (SOReg) and the Swedish Knee Arthroplasty Register (SKAR) between 2007 and 2019 and 2009 and 2020, respectively. The cohort was divided into two groups; patients who underwent TKA before BS (TKA-BS) and patients who underwent BS before TKA (BS-TKA). Multilinear regression analysis and a Cox proportional hazards model were used to analyze weight change after BS and the risk of revision after TKA.

RESULTS

Of the 584 patients included in the study, 119 patients underwent TKA before BS and 465 underwent BS before TKA. No association was detected between the sequence of surgery and total weight loss 1 and 2 years post-BS, - 0.1 (95% confidence interval (CI), - 1.7 to 1.5) and - 1.2 (95% CI, - 5.2 to 2.9), or the risk of revision after TKA [hazard ratio 1.54 (95% CI 0.5-4.5)].

CONCLUSION

The sequence of surgery in patients undergoing both BS and TKA does not appear to be associated with weight loss after BS or the risk of revision after TKA.

Effect of Weight Change on Patient-Reported Outcomes Following Total Joint Arthroplasty

BACKGROUND

Increased body mass index (BMI) has been previously described as a risk factor for complications after total joint arthroplasty (TJA); however, its effect on patient-reported outcomes has not been thoroughly investigated. This study examines the effect of postoperative weight change on the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) scores for total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients.

METHODS

A retrospective review of 988 patients undergoing THA or TKA was performed. PROMIS-PF scores and BMI were recorded throughout the study duration. Patients were classified by a 5% change in BMI. A univariate analysis evaluated differences across groups. Mixed-effect models evaluated predictors of change in functional score over the postoperative follow-up time.

RESULTS

43.1% patients had a THA and 56.9% patients had a TKA. At 0 to 3 months, 92% of patients had no change in BMI, 3 to 6 months 82% had no change, and 6 to 12 months 80% had no change. There were no significant demographic or comorbidity differences across groups for both THA and TKA. Similar improvements in PROMIS-PF scores were observed across weight change groups. In the mixed-effect models, postoperative time was found to be a significant predictor of postoperative PF score. Both THA and TKA patients saw greater improvements in PROMIS-PF scores in patients with lower preoperative BMIs.

CONCLUSION

These results demonstrate most patients do not experience substantial changes in weight following TJA. However, lower BMIs at the time of surgery were associated with an increased functional improvement. Therefore, efforts to optimize BMI should be focused preoperatively to improve surgical outcomes.

Outcomes of Total Joint Arthroplasty in Black, Asian, Minority Ethnic Groups Versus Local Population: A Retrospective Review

BACKGROUND

 Total hip and knee replacement decrease the disability caused by osteoarthritis of the lower extremities. Although it has been established that racial and ethnic minorities underutilize these procedures, little data on postoperative outcomes exists. The impact of race on postoperative Oxford scores and complications following total joint arthroplasty (TJA) will be investigated in this retrospective review.

METHODS

 A retrospective review of 120 elective primary TJA procedures was undertaken between January 2016 and December 2019 in a single institution. To measure variations between the various groups, t-tests were used on their Oxford scores, and chi-squared bivariate regression was used to classify all categorical variables and the association of ethnicity and surgery type with gender.

RESULTS

 There were 62 (51.6%) White patients and 59 (49.1.0%) Black, Asian, Minority Ethnic (BAME) patients in total. The majority of the patients were females (60.9% vs 39.2%, p = 0.032). Low vitamin D levels were seen in a small percentage of patients in the sample (15.8% vs 84.2%, p = 0.460). There is a statistically important connection (p = 0.001) between the surgery type (total knee replacement [TKR]/total hip replacement [THR]) and gender; 41 females had TKR surgery, and 32 had THR surgery.

CONCLUSION

The study found that the relationships between ethnicity (White/BAME) and gender as well as surgery type (TKR/THR) and gender are statistically important. In all cases with low vitamin D and normal vitamin D levels, White patients had higher overall Oxford hip scores than the BAME patients. To comprehend the differences discovered, further research is needed. To try to eliminate the difference, targeted approaches should be created.

The Fate of Morbidly Obese Patients With Joint Pain: A Retrospective Study of Patient Outcomes

BACKGROUND

The number of obese patients seeking a total joint arthroplasty (TJA) continues to increase. Weight loss is often recommended to treat joint pain and reduce risks associated with TJA. We sought to determine the effectiveness of an orthopedic surgeon's recommendation to lose weight.

METHODS

We identified morbidly obese (body mass index (BMI) 40-49.9 kg/m²) and super obese (BMI ≥50 kg/m²) patients with hip or knee osteoarthritis. Patients with less than 3-month follow-up were excluded. Patient characteristics (age, gender, BMI, comorbidities), disease characteristics (joint affected, radiographic osteoarthritis grading), and treatments were recorded. Clinically meaningful weight loss was defined as weight loss greater than 5%.

RESULTS

Two hundred thirty morbid and 50 super obese patients were identified. Super obese patients were more likely to be referred to weight management (52.0% vs 21.7%, P < .001) and were less likely to receive TJA (20.0% vs 41.7%, P = .004). Each 1 kg/m² increase in BMI decreased the odds of TJA by 10.9% (odds ratio = 0.891, 95% confidence interval: 0.833-0.953, P = .001). Forty (23.0%) of the nonoperatively treated patients achieved clinically meaningful weight loss, and 19 (17.9%) patients who underwent TJA lost weight before surgery. After surgery, the number of patients who achieved a clinically meaningful weight loss grew to 32 (30.2%).

CONCLUSION

In morbid and super obese patients, increasing BMI reduces the likelihood that a patient will receive TJA, and when counseled by their orthopedic surgeon, few patients participate in weight-loss programs or are otherwise able to lose weight. Weight loss is an inconsistently modifiable risk factor for joint replacement surgery.

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

BACKGROUND

Previous studies evaluating weight changes following total knee arthroplasty (TKA) were performed on heterogenous cohorts. However, no study has evaluated weight changes in a cohort of simultaneous-bilateral TKA (SB-TKA) patients. This study aimed to evaluate the prevalence of patients who lost or gained weight, determine if postoperative weight change influences functional outcome, and identify predictors of weight change after SB-TKA.

METHODS

Prospectively collected registry data of 560 patients who underwent SB-TKA were reviewed. Patients were assessed preoperatively, at 6 months, and 2 years using the Knee Society Score, Oxford Knee Score, Short-Form 36, and range of motion. Change in body mass index (BMI) >5% was used to categorize patients into 3 groups: lost, maintained, or gained weight. Analysis of variance, Kruskal-Wallis test, and chi-squared test were used to compare functional outcomes between groups. Multivariable logistic regression evaluated predictors for postoperative weight changes.

RESULTS

At 2 years, 59% of patients maintained weight, 28% of patients gained weight, and 13% of patients lost weight. All groups experienced similar improvements in functional outcomes, rates of minimal clinically important difference attainment, and patient satisfaction (P > .05). Older patients were more likely to gain weight (P < .05). Patients with higher preoperative BMI were more likely to gain weight (P < .05) and less likely to lose weight (P < .05). Patients with greater preoperative comorbidities were less likely to lose weight (P < .05).

CONCLUSION

Up to 41% of patients experience significant weight changes after SB-TKA. Older patients with higher preoperative BMI were more likely to gain weight, while higher preoperative BMI with more comorbidities were less likely to lose weight following SB-TKA; however, postoperative weight changes do not appear to affect functional outcomes.

LEVEL OF EVIDENCE

III, therapeutic study.

Minority Race and Ethnicity is Associated With Higher Complication Rates After Revision Surgery for Failed Total Hip and Knee Joint Arthroplasty

BACKGROUND

Racial and ethnic disparities in access to hip and knee total joint arthroplasty (TJA) and postoperative outcomes have wide-reaching implications for patients and the health care system. The aim of this study is to evaluate the effect of ethnicity on clinical outcomes and complications following revision hip and knee TJA.

METHODS

A single-institution, retrospective analysis of a consecutive series of 4424 revision hip and knee TJA patients was evaluated. Student's t-test and chi-squared analysis were used to identify significant differences in patient demographics and clinical outcomes between Caucasians and various ethnic minorities, including African Americans, Hispanics, and Asians.

RESULTS

When compared with white patients, African American patients demonstrated a significantly higher BMI (P = .04), ASA score (P = .04), length of hospital stay (P = .06), and postoperative infection rates (P = .04). Hispanics demonstrated a significantly higher BMI (P = .04), when compared with white patients, alongside a significantly higher risk for postoperative infection (P < .01). African American demonstrated a significantly higher ASA score (P = .02; P = .03), when compared with Hispanics and Asians, alongside a significantly increased length of stay (P = .01) and higher risk for postoperative infection (P = .02).

CONCLUSION

The study findings demonstrate an underutilization of revision TJA by ethnic minority groups, suggesting that disparities in access to orthopedic surgery increase from primary to revision surgery despite higher failure rates of minority ethnic groups reported after primary TJA surgery. In addition, inferior postoperative outcomes were associated with African Americans and Hispanics, when compared to white patients, with African Americans demonstrating the highest risk of postoperative complications.

Patterns of Weight Change and Their Effects on Clinical Outcomes Following Total Knee Arthroplasty in an Asian Population

BACKGROUND

This prospective cohort study was designed to evaluate weight change patterns and their effects on clinical outcomes following total knee arthroplasty (TKA) in the Asian population. We hypothesized that Asian patients will have a different pattern of weight change following TKA compared to Western patients and that weight loss following TKA will be associated with better clinical outcomes.

METHODS

A cohort of consecutive patients who underwent TKA from 2004 to 2015 was included. All patients received a conventional posterior-stabilized TKA implant and underwent a standard perioperative care pathway. Assessments were done preoperatively, at 6 months, and 2 years after surgery. The range of motion, Knee Society Score, Oxford Knee Score, and the Short-Form 36 questionnaire were used to assess outcomes. Height and weight of patients were recorded for body mass index (BMI) calculation. Patterns of weight loss following TKA in this cohort were charted. Clinical outcomes were then analyzed against the change in BMI.

RESULTS

A total of 602 patients (602 knees) were reviewed. Mean age was 66.39 ± 7.27 years. Mean BMI was 27.75 ± 4.51 kg/m². Overall, 63.12% of all our patients gained weight following TKA. Moreover, weight loss did not influence patients' odds for better clinical outcomes. Furthermore, patients who were in the preoperative BMI category of obese class I were more likely to gain weight as compared to those in the normal category (odds ratio 0.35, 95% confidence interval 0.2-0.61, P < .001). Moreover, older people were more likely to gain more weight compared to younger people. We also showed that the mean 2-year Knee Society Knee Score was significantly higher in the patients who gained weight while the patients who lost weight had the highest mean 2-year Oxford Knee Score and the lowest mean 2-year Knee Society Function Score.

CONCLUSION

Asians tend to gain weight following TKA. However, this weight change following TKA does not affect clinical outcomes, which remain good across all BMI groups.

LEVEL OF EVIDENCE

Therapeutic Level III.

Weight changes after total knee arthroplasty in Chinese patients: a matched cohort study regarding predictors and outcomes

Background

The purpose of this study was to compare 2-year BMI changes between patients undergoing simultaneous bilateral total knee arthroplasty (TKA), staged bilateral TKA, and unilateral TKA. We also sought to determine the predictors of weight change and whether clinically meaningful weight changes affected outcomes.

Patients and methods

This retrospective, single-institution study included 202 Chinese patients who received simultaneously bilateral TKA, staged bilateral TKA, or unilateral TKA from 2008 to 2015. There were 49 simultaneous bilateral TKAs, 52 staged bilateral TKAs, and a matched 101 unilateral TKAs.

Results

66.8% (135/202) of patients lost weight after TKA surgery. However, 20.7% (42/202) of patients experienced clinically meaningful weight loss (a BMI decrease of more than 5%). Paired t test showed that 2-year BMI was significantly lower than preoperative BMI (p < 0.001). Weight loss was significantly different between the surgical strategy (p < 0.001). Preoperative BMI and age were predictive of clinically significant weight loss or gain (p < 0.05). Multiple linear regression showed that post-operative weight loss was associated with better Western Ontario and McMaster Universities Osteoarthritis Index and SF-36 scores (p < 0.001).

Conclusion

Patients after TKA experience weight loss. Age and preoperative BMI predict clinically meaningful weight change. Simultaneous bilateral TKA is associated with higher likelihood of weight loss. Clinically meaningful weight loss experiences better patient-reported outcomes.

Differences in Perioperative Outcomes and Complications Between African American and White Patients After Total Joint Arthroplasty

BACKGROUND

Racial disparities in healthcare utilization and outcomes have been reported and have wide-reaching implications for individual patient and healthcare system; as providers we bear an ethical burden to address this disparity and provide culturally competent care. This study will examine the influence of race on length of stay, discharge disposition, and complications requiring reoperation following total joint arthroplasty (TJA).

METHODS

Single institution retrospective analysis of a consecutive series of 7208 primary TJA procedures performed between July 2013 and June 2017 was conducted. Chi-squared and t-tests were used to quantify differences between the groups and multiple logistic regression was used to identify race as an independent risk factor.

RESULTS

In total, 6182 (84.3%) white and 1026 (14.0%) African American (AA) patients were included. AA patients were younger (63.62 vs 66.84 years, P < .001), more likely female (68.8% vs 57.0%, P < .001), had a longer length of stay (2.19 vs 2.00 days, P < .001), more likely to experience septic complications (1.3% vs 0.5%, P = .002) and manipulation under anesthesia (3.9% vs 1.8%, P < .001), and less likely to discharge home (67.1% vs 81.1%, P < .001). Multiple logistic regression showed that AA patients were more likely to discharge to a facility (adjusted odds ratio 2.63, 95% confidence interval 2.19-3.16, P < .001) and experience a manipulation under anesthesia (adjusted odds ratio 1.90, 95% confidence interval 1.26-2.85, P = .002).

CONCLUSION

AA patients undergoing TJA were younger with longer length of stay and a higher rate of nonhome discharge; AA race was identified as an independent risk factor. Further study is required to understand the differences identified in this study. Targeted interventions should be developed to attempt to eliminate the disparity.

Comparison of a Patient-Centered Weight Loss Program starting before versus after knee replacement: A pilot study

BACKGROUND

Most patients risk gaining weight in the years after knee replacement, adding further concern to a population that is mostly overweight/obese prior to surgery.

OBJECTIVE

Via a randomised pilot study, we assessed changes in weight during a Patient Centered Weight Loss Program (PACE) initiated either before or after knee replacement, while simultaneously examining the feasibility of recruiting and retaining participants over 26 weeks.

METHODS

Recruitment outreach was made to 133 patients scheduled for knee replacement. Sixteen participants were randomised to a 14-session weight loss program that started either ≤6 weeks before surgery (PACE) or at 12 weeks post-op (Delayed PACE). Repeated measures ANOVAs were used to examine preliminary changes in weight, function, patient-reported outcomes, and physical activity across time (baseline/pre-op, 12 and 26 weeks after surgery) and group.

RESULTS

Retention was 75% and 69% at 12 and 26 weeks after surgery, respectively. Weight significantly decreased across the 26 weeks (P<0.001). A group by time interaction (P=0.03) demonstrated Delayed PACE [-7.6±5.9kg (-7.9±5.9%)] lost significantly more weight than PACE [-2.5±2.7kg (-2.6±2.6%)] participants at 26 weeks. Significant improvements across time were seen for all function and patient reported outcomes, however activity did not change.

CONCLUSION

Conducting a behavioural intervention was challenging but feasible in a knee replacement population, with preliminary evidence suggesting that initiating a program 12 weeks after surgery produces greater weight losses at 26 weeks compared to a program starting before knee replacement.

Body mass index changes after unicompartmental knee arthroplasty do not adversely influence patient outcomes

PURPOSE

The objective of this study is to evaluate the prevalence of patients who lost or gained weight following unicompartmental knee arthroplasty (UKA), the effect of post-operative body mass index (BMI) changes on functional outcomes and quality of life (QoL), and predictive factors associated with BMI changes.

METHODS

Prospectively collected data of 1043 patients who underwent UKA between 2000 and 2014 were reviewed. BMI, Knee Society Knee Score and Function Score, Oxford Knee Score (OKS), Short-Form 36 (SF-36) Physical Component Score (PCS) and Mental Component Score and proportion of patients attaining OKS/SF-36 minimal clinically important differences (MCID) were recorded preoperatively and at 2 years post-operatively. The patients were stratified into three groups based on weight changes for further analysis.

RESULTS

Following UKA, 138 (13.3%) patients had lost weight, 695 (66.6%) maintained their weight, and 210 (20.1%) gained weight. Patients in all groups demonstrated significant improvements in functional and SF-36 PCS scores at 2 years post-operatively. There were no significant differences in functional outcomes, QoL or revision rate between the groups. Post-operative BMI changes were not correlated with any outcome scores or attainment of MCID (n.s.).

CONCLUSIONS

This is the first study that evaluates change in BMI following UKA. It demonstrated a higher proportion of patients who gained weight as compared to those who lost weight. Post-operative BMI changes did not appear to affect outcomes of UKA. These findings will provide important information to surgeons when counselling patients regarding BMI change and its effect on outcomes after UKA.

LEVELS OF EVIDENCE

Level III.

Do patients lose weight after total knee replacement?

OBJECTIVE

Several studies show that patients undergoing total knee arthroplasty (TKA) tend to maintain or gain weight after the procedure, which would result in increased wear of the prosthesis and new surgical interventions in a smaller period of time in comparison with patients with adequate body mass index (BMI). The aim of this study was to investigate the effect of TKA surgery on these patients' BMI.

METHODS

Initially the records were analyzed, chosen at random from 91 patients undergoing TKA during the period from August 2011 to July 2013. Patients were stratified by BMI as normal weight (BMI between 20 and 25), overweight (BMI between 25 and 30), and obesity (BMI > 30). They were re-evaluated in a minimum period of 18 months.

RESULTS

The mean age of the sample population was 68.1 years; 69.1 for men and 67.2 for women. The mean preoperative BMI was 27.24 kg/m². Among the study participants, in the preoperative period, 17 patients had normal weight, 65 were overweight, and nine were obese. Postoperative analysis showed weight loss in 41 patients (46%), and weight gain in 50 patients (54%). The mean postoperative BMI was 27.16 kg/m², in general, experiencing a slight decline in the mean BMI of 0.08 kg/m².

CONCLUSION

Patients who underwent TKA did not achieve significant reduction in BMI after surgery.

New Joints, Same Old Weight: Weight Changes After Total Hip and Knee Arthroplasty

Obesity is a well-known risk factor for postoperative complications following total joint arthroplasty. However, because the operation is often successful, orthopedic surgeons continue to operate on obese individuals, and many surgeons do so under the assumption that patients will lose weight after they are able to walk and exercise without pain. In this article, we review a recent study by Ast et al., who performed a retrospective review, using a single-center institutional registry, to determine (1) whether patients do actually lose weight after total hip and/or total knee arthroplasty, (2) whether there are predictors of postoperative weight change, and (3) whether postoperative weight changes affect patient-reported clinical outcomes. The principle conclusion was that most patients maintained their body mass index (BMI) after total hip and total knee arthroplasty (73 and 69%, respectively). However, patients undergoing total knee arthroplasty, patients who had a higher preoperative BMI, and female patients were more likely to lose weight postoperatively. When examined in the context of the current literature, this study provides valuable information for the preoperative counseling of total joint arthroplasty candidates, especially in the setting of obesity.

Does Body Mass Index Decrease Over Time Among Patients Who Undergo Total Knee Arthroplasty Compared to Patients With Osteoarthritis? Data From the Osteoarthritis Initiative

BACKGROUND

Although total knee arthroplasty (TKA) is associated with improved patient-reported function, pain, and quality of life, the effects on weight loss are less certain. In this study, we use data from a large, prospective cohort study of osteoarthritis (OA) patients to compare the changes in body mass index (BMI) across 6 years in OA patients who received TKA compared with OA patients who did not receive TKA.

METHODS

Using data from the Osteoarthritis Initiative, a prospective cohort study of patients with OA, our study divided patients into two groups: patients who received a TKA during the Osteoarthritis Initiative study (N = 140) and those who did not (N = 697). The initial BMI, final BMI, and change in weight over 72 months were compared between groups. Subgroup analysis was performed by dividing patients by their initial BMI, gender, and age.

RESULTS

The TKA group's change in weight, initial BMI, and final BMI were not significantly different from the non-TKA group over 72 months (weight change: -0.763 kg vs +0.191 kg; P = .597). Subgroups of women and patients aged 51-60 years with TKA gained more weight than respective non-TKA OA patients.

CONCLUSIONS

Overall, patients who received TKA did not lose or gain more weight than OA patients who did not receive TKA. Patients with longer follow-up after TKA (>2 years) still gained weight on average. Despite the improved patient-reported pain levels, function, and quality of life after TKA, it appears that TKA alone is not a sufficient intervention for obesity.