Study Seeks to Determine if Weight Loss Surgery before TKA Improves Outcomes

    Could weight loss surgery before total knee arthroplasty (TKA) improve outcomes or even eliminate the need for joint replacement in severely overweight patients? A multicenter study now underway aims to answer that question.

    The study, known as SWIFT (Surgical Weight-Loss to Improve Functional Status Trajectories Following Total Knee Arthroplasty), is enrolling patients at a number of hospitals nationwide. The goal is to compare outcomes in individuals who have bariatric surgery versus those who do not have the weight loss surgery before TKA. Researchers also aim to determine if losing a significant amount of weight could enable patients to delay TKA or postpone it indefinitely.

    “This is the first prospective study of its kind,” said Alexander McLawhorn, MD, an orthopedic surgeon and lead investigator at the Hospital for Special Surgery (HSS), one of the participating institutions. “We hypothesize that weight loss resulting from bariatric surgery prior to knee replacement will improve joint replacement outcomes in obese patients with painful arthritis.

    “It will also be interesting to see if weight loss and reduced stress on their joints will result in less pain and improved mobility, which may enable patients to postpone knee replacement surgery.”

    A previous retrospective study at HSS found that in severely obese patients, bariatric surgery performed prior to a total hip or knee replacement surgery reduces complications while patients are in the hospital and in the first 90 days after the procedure.

    In the current study, researchers will divide enrolled patients into 2 groups:

    • The first group will undergo bariatric surgery prior to TKA.
    • The second group will have TKA only.

    Approximately 9 to 13 months after bariatric surgery, participants in the first group will be evaluated to determine:

    • If they still wish to go ahead with TKA
    • If they feel the surgery can be delayed
    • If they believe they no longer need TKA

    Those who choose to have TKA will complete 9 research visits over the course of 3.5 to 4 years, in addition to the standard of care visits required for bariatric surgery and knee replacement. Research visits will include:

    • The completion of questionnaires to measure pain, physical functioning, quality of life, and patient satisfaction
    • Vital sign measurements
    • Physical function assessments, including the ability to walk a quarter of a mile and climb stairs

    Participants in the control group will undergo a TKA without weight loss surgery and will complete 6 research visits over the course of 2.5 to 3 years, in addition to the standard of care visits required for a TKA procedure. The research visits for this group will include the same evaluation activities as those in the bariatric surgery group.

    More information about the study can be found here.