NCT06896240 · Hospital for Special Surgery, New York
Fiber Smoothie Supplement
What this study is about
This study aims to assess the feasibility of a 2-week dietary whole-food smoothie intervention and compare outcomes between two groups: patients that integrated a daily whole food plant-based smoothie into their diet for two weeks prior to surgery, and a control group of revision TKA patients that made no nutritional changes to their diet prior to surgery. The main research questions are: 1.
View original scientific description
This study aims to assess the feasibility of a 2-week dietary whole-food smoothie intervention and compare outcomes between two groups: patients that integrated a daily whole food plant-based smoothie into their diet for two weeks prior to surgery, and a control group of revision TKA patients that made no nutritional changes to their diet prior to surgery. The main research questions are: 1. Among patients planned for elective TKA revision surgery, what is the feasibility of a 2-week dietary intervention implemented 2 weeks prior to surgery? \[Outcomes will be compliance, noted barriers and/or facilitators, satisfaction with diet\] 2. Determine if the implementation of a daily whole food plant- based smoothie dietary supplement 2 weeks prior to TKA revision surgery will reduce inflammation -measured in plasma levels of IL-6 and CRP- at POD0, POD1, POD2, POD3, and 6 Weeks Post-operative as compared to 1) baseline (prior to dietary intervention initiation) and 2) control patients who did not make changes in their diet prior to surgery. 3. Determine if the implementation of a daily whole food plant-based smoothie dietary supplement 2 weeks prior to TKA revision surgery will result in quantifiable changes in the gut microbiome composition -measured via fecal samples- as compared to control patients who did not make changes in their diet prior to surgery. 4. Determine if the implementation of a daily whole food plant- based smoothie dietary supplement 2 weeks prior to TKA revision surgery will result in improved immediate postoperative pain -measured through numeric rating scale (NRS) pain scores- and opioid use -measured in morphine milligram equivalents (MME)- as compared to control patients. 5. Compare patient satisfaction and adoption of nutritional behavioral changes in patients implementing a whole food plant-based smoothie 2 weeks prior to TKA revision surgery to patients undergoing the same surgery but did not me pre-surgery dietary changes. The researcher's primary outcome is measuring feasibility and patient compliance with smoothie consumption. Secondarily, the investigators are interested in measuring if the preoperative smoothie can alter the gut microbiome and decrease systemic inflammation, leading to lowered post-operative pain and opioid use.
Interventions
DIETARY_SUPPLEMENT
Assigned Interventions
The "Green Smoothie Guide" from the American College of Lifestyle Medicine contains guidelines for a 6-step smoothie to include whole and high fiber foods.
Primary outcome measures
Feasibility Measured in Terms of Compliance
Time frame: Daily for 14 days pre-operative
Compliance is measured as number of days in the two-week intervention timeframe that patients reported having consumed the smoothie. The investigators will conduct fourteen daily phone calls to assess yes/no smoothie intake and ingredients used. Informed by nutrition compliance in the literature, the investigators will apply an 80% threshold for compliance rate which translates to roughly 11/14 days. The compliance range is 0%-100% or 0-14 days with 100% or 14 days indicating higher smoothie compliance and a more favorable outcome.
Feasibility Measured in Terms of Noted Barriers/Facilitators
Time frame: Day 0
Noted barriers/facilitators are open-ended questions in unstructured free text format. A feedback form will be sent to participants, and feedback and suggestions will be recorded by the investigators.
Feasibility Measured in Terms of Satisfaction with Diet
Time frame: Baseline and 6 weeks post-operative
The quantification of satisfaction with diet using the verified Diet Satisfaction Scale with 28 questions. Individual questions are scored on a scale of 1-5 with a higher score indicating higher diet satisfaction and a more favorable outcome. Scores from each question will be compiled into a total score for the questionnaire.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Scheduled for revision TKA at HSS with participating surgeons; not as a result of infection or trauma and all components (tibial and femoral) needing replacement
- Age between 40 and 80
- Diagnosed with osteoarthritis
- Diagnosed with 2+ modifiable chronic lifestyle diseases: Type 2 DM, CVD (such as CAD, heart disease, stroke, HTN), stress, anxiety, depression, ADHD, metabolic syndrome, certain types of cancer (such as breast, colorectal, lung, prostate), Alzheimer's disease, vascular cognitive impairment, CKD, RA, asthma, chronic pain conditions (such as chronic back pain and osteoarthritis), fibromyalgia, migraines, COPD (Steiber 2011, Grant 2014)
- ASA Class 1 ('normal' healthy patient) or 2 (patient with mild systemic disease and no functional limitations; the diseases the patient has are well controlled)
- Ability to understand written and spoken English
- Willing to complete entire pre-operative and post-operative work up in NYC, main campus site
- Willing to follow a 2-week smoothie supplement, including willingness to purchase ingredients and have access to a blender for preparation
Exclusion criteria
- Age \>80 years or \<40 years
- Revision due to infection or trauma
- ASA class 3 (patient with severe systemic disease that results in functional limitations) or 4 (patient with severe systemic disease that is a constant threat to life)
- Not interested or unable to provide informed consent
- Unstable weight (\>5kg weight change in the past 3 months, documented in Epic) or currently on weight loss drugs such as GLP-1 agonists (Prasad et al., Cardiovasc Diabetol 2022; empagliflozin CRP studies.)
- Active infection, flare-up of seasonal allergies, or physical trauma (all can alter CRP)
- Medication changes the month leading up to surgery
- Specifically medications altering inflammation: Statins (Ridker 2008), steroids (Boumpas et al., Ann Intern Med 1993; glucocorticoid cytokine modulation research.), DMARDS/biologics/immunosuppressants (Clinical rheumatology guidelines, biologic RCTs (e.g., TNF inhibitors, IL-6 inhibitors), Colchicine (Tardif et al., N Engl J Med 2019; colchicine cardiovascular inflammation studies.), hormone replacement therapies (Ridker et al., JAMA 1999; OCs and CRP meta-analyses.), new psychiatric medications (Miller \& Raison, Nat Rev Immunol 2016; psychotropic-inflammation associations.)
- BMI \>40 kg/m2
- Food intolerance/allergy/sensitivity to ingredients suggested for smoothies
- History of IBD (and IBD medication)
- History of bariatric surgery
- History of cancer
- History of thyroid disease
- History of or current drug abuse
- Current smoker
- Any patient with an electronic cardiac implant
Where
- New York, New York
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 15, 2026 · Source of record for eligibility and locations