University of California, San Francisco
This study is looking at whether taking a nutritional supplement before and after knee replacement surgery affects normal recovery. The supplement is Xcelerated Recovery (XR), an over-the-counter supplement made with essential amino acids (EAAs), which are building blocks of protein that the body cannot make on its own. Participants aged 65 and older with planned knee replacement surgery, and signs of nutritional risk or reduced muscle strength on short screening questionnaires, will be invited to join. Participants are assigned by chance to one of two groups. One group receives usual care plus the XR supplement, taken twice a day starting 7 days before surgery and continuing for 14 days after surgery. The other group receives usual care without the supplement. Everyone in the study wears a small temporary skin sensor (similar to a temporary tattoo) on the knee and uses a smartphone app to take scans that measure knee size. Participants also have in-person visits before surgery and 2 weeks and 1 month after surgery. The main goal is to measure how knee and leg size (circumference) changes after surgery in each group. Researchers will also look at muscle strength, knee movement, walking and mobility tests, and reported pain. This study is not testing the supplement as a treatment for any disease or medical condition. The results may help researchers better understand how nutrition relates to normal recovery after knee replacement surgery.
Background: Total knee arthroplasty (TKA) is followed by a normal recovery period that includes shifts in tissue fluid, loss of muscle, and reduced mobility. Perioperative nutrition guidance recommends adequate protein intake (at least 1.2 g/kg/day) to support muscle protein balance. Studies of essential amino acid (EAA) supplementation around the time of TKA have reported better preservation of muscle mass and functional mobility. However, few studies have examined over-the-counter EAA-based supplements, or their relationship to postoperative limb circumference. Wearable technologies, such as…
Inclusion Criteria: * Adults over 65 years old * Nutritional deficiency, defined as MNA-SF ≤11, and/or sarcopenia, defined as SARC-F ≥4 * Undergoing elective primary unilateral total knee arthroplasty (TKA) for osteoarthritis at UCSF * Able to provide written informed consent * Willing to comply with supplementation and follow-up requirements Exclusion Criteria: * Revision arthroplasty * BMI \>35 kg/m² * Arthroplasty for inflammatory arthropathy, rheumatoid arthritis, or trauma * Active cancer or severe metabolic disorder * Chronic lower-extremity edema * Preoperative ankle swelling * Lymph…
Xcelerated Recovery (XR) is a commercially available, EAA-based multi-ingredient nutritional supplement. Participants assigned to the intervention arm will dissolve the full XR supplement in water and consume it twice daily. Each serving contains 19.2 g of essential amino acids, providing 38.4 g of essential amino acids per day. Supplementation will begin 7 days before total knee arthroplasty and continue through 14 days after surgery. XR is being evaluated for its association with measures of normal physiological recovery following surgery, including tissue fluid balance assessed through changes in limb circumference and measures of physical function.