Peanut Protein Supplementation to Prevent Muscle Atrophy and Improve Recovery Following Total Knee Arthroplasty

Peanut Protein Supplementation to Prevent Muscle Atrophy and Improve Recovery Following Total Knee Arthroplasty

This randomized controlled trial will study the effects of peanut protein supplementation on changes in muscle size and quality in patients undergoing total knee arthroplasty.

Total knee arthroplasty (TKA) is an effective treatment for patients with knee osteoarthritis (OA) accompanied by severe pain and functional limitations. With the success of this treatment and increasing incidence of OA, it has been projected that ~3.5 million older adults will undergo TKA annually by the year 2030. While TKA is effective for reducing pain and improving health-related quality of life, TKA patients experience significant skeletal muscle atrophy and weakness in the surgical leg following surgery which, long-term, can compromise balance, functional mobility and increase fall risk. Thus, interventions to mitigate muscle atrophy and weakness post-surgery are essential to improving long-term outcomes in patients undergoing TKA.

This randomized controlled trial will study the effects of peanut protein supplementation on changes in muscle size and quality in patients undergoing total knee arthroplasty. Patients (n=30) between the ages of 60-75 years scheduled to undergo total knee arthroplasty at the Jack Hughston clinic/hospital will be recruited to participate. Participants will be stratified by gender and randomized to a peanut protein (PP) supplementation (72g daily, n=15) or waitlist control (standard care with no PP, n=15) group who will be provided with PP following the intervention. Participants in the PP group will consume PP daily starting 7 days prior to surgery and for 6 weeks post-surgery. Participants will be monitored for changes in muscle size and quality (peripheral quantitative computed tomography), upper-leg strength (isokinetic dynamometry), knee range of motion (ROM; goniometry), pain (questionnaire and pressure algometry), and functional mobility outcomes (questionnaire, timed up and go, 2-min walk test) prior to surgery and at 6 and 12-weeks post-surgery.

Inclusion Criteria:

• total knee arthroplasty scheduled within two weeks under the care of surgeons at the Jack Hughston Clinic

Exclusion Criteria:

• history of invasive lower extremity surgery within the last 5 years
• allergy to peanuts or peanut products
• Body Mass Index <20 or >35 kg/m2
• currently adhering to a restrictive weight loss diet
• current or recent (within the last 2 months) steroid use
• any physical condition that interferes with performing post-surgery rehabilitation
• known peripheral vascular disease, kidney disease, liver disease, or uncontrolled endocrine disorder
• known overt cardiovascular or metabolic such as heart disease/failure or diabetes
• Radiation exposure within the last 6 months other than dental x-rays or associated with current knee treatment/diagnosis