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.

Information and BMI limits for patients with obesity eligible for knee arthroplasty: the Swedish surgeons' perspective from a nationwide cross-sectional study.

BACKGROUND: In the past decades, the incidence of obesity has increased worldwide. This disease is often accompanied with several comorbidities and therefore, surgeons and anesthesiologists should be prepared to provide optimal management for these patients. The aim of this descriptive cross-sectional study was to map the criteria and routines that are used by Swedish knee arthroplasty surgeons today when considering patients with obesity for knee arthroplasty. METHODS: A survey including 21 items was created and sent to all the Swedish centers performing knee arthroplasty. The survey included questions about the surgeons' experience, hospital routines of preoperative information given and the surgeons' individual assessment of patients with obesity that candidates for knee arthroplasty. Descriptive statistics were used to present the data. RESULTS: A total of 203 (64%) knee surgeons responded to the questionnaire. Almost 90% of the surgeons claimed to inform their patients with obesity that obesity has been associated with an increased risk of complications after knee arthroplasty. Seventy-nine percent reported that they had an upper BMI limit to perform knee arthroplasty, a larger proportion of the private centers had a BMI limit compared to public centers. The majority of the centers had an upper BMI limit of 35. CONCLUSION: The majority of the knee arthroplasty surgeons in Sweden inform their patients with obesity regarding risks associated with knee arthroplasty. Most centers that perform knee arthroplasties in Sweden have an upper BMI limit.

Pain, Function, and Satisfaction After Total Knee Arthroplasty, with or Without Bariatric Surgery.

BACKGROUND: The impact of obesity on patient-reported outcome (PRO) after total knee arthroplasty (TKA) surgery has demonstrated varying results. We evaluated knee pain, Activity in Daily Life function (ADL), and satisfaction after TKA surgery in patients with and without prior bariatric surgery (BS). METHODS: Scandinavian Obesity Surgery Registry (SOReg) and the Swedish Knee Arthroplasty Register (SKAR) were used to identify patients operated on with primary TKA for osteoarthritis (OA) between 2009 and 2019 that had a BS within 2 years before the TKA (BS group). These patients were compared to patients with TKA without prior BS (no BS group). The patients filled in the Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and one year postoperatively as well as satisfaction with the surgery one year postoperatively. Multiple linear regression analysis was used to evaluate 1-year postoperative KOOS pain and ADL function between the 2 groups. Adjustments were made for sex, age, and preoperative KOOS pain and ADL function respectively. RESULTS: Forty-four patients were included in the BS group and 3,525 patients in the no BS group. We found no statistically or clinically significant difference in one-year postoperative KOOS pain and ADL function between the BS group and the no BS group. The majority of the patients in both groups were classified as satisfied or very satisfied one year postoperatively to the TKA. CONCLUSIONS: Our results indicate that patients without BS prior to the TKA gain similar 1-year outcome in pain, ADL function and satisfaction as patients with prior BS.

Bariatric surgery prior to total knee arthroplasty is not associated with lower risk of revision: a register-based study of 441 patients.

Background and purpose - Obesity is a considerable medical challenge in society. We investigated the risk of revision for any reasons and for infection in patients having total knee arthroplasty (TKA) for osteoarthritis (OA) within 2 years after bariatric surgery (BS) and compared them with TKAs without BS.Patients and methods - We used the Scandinavian Obesity Surgery Registry (SOReg) and the Swedish Knee Arthroplasty Register (SKAR) to identify patients operated on in 2009-2019 with BS who had had primary TKA for OA within 2 years after the BS (BS group) and compared them with TKAs without prior BS (noBS group). We determined adjusted hazard ratio (HR) for the BS group and noBS group using Cox proportional hazard regression for revision due to any reasons and for infection. Adjustments were made for sex, age groups, and BMI categories preoperatively.Results - 441 patients were included in the BS group. The risk of revision for infection was higher for the BS group with HR 2.2 (95% CI 1.1-4.7) adjusting for BMI before the TKA, while the risk of revision for any reasons was not statistically significant different for the BS group with HR 1.3 (CI 0.9-2.1). Corresponding figures when adjusting for BMI before the BS were HR 0.9 (CI 0.4-2) and HR 1.2 (CI 0.7-2).Interpretation - Our findings did not indicate that BS prior to TKA was associated with lower risk of revision.