Recruiting

Smoothie Intervention

Sponsor:

Hospital for Special Surgery, New York

Code:

NCT06896240

Conditions

Total Knee Arthroplasty Revision

Inflammatory Markers

Gut Microbiota

Eligibility Criteria

Sex: All

Age: 40 - 70+

Healthy Volunteers: Not accepted

Interventions

Assigned Interventions

Study Details

Brief summary:

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.

Conditions

Total Knee Arthroplasty Revision

Inflammatory Markers

Gut Microbiota

Study ID

NCT06896240

Start date

Apr 28, 2026

Status verified date

Jul, 2026

Completion date

Jan 1, 2028

Anticipated

Primary completion date

Jan 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 40 - 70+

Healthy Volunteers: Not accepted

Inclusion:

  • 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:

  • 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
  • Pregnancy
  • Current smoker
  • Any patient with an electronic cardiac implant

Study Design

Enrollment

24 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

no intervention: Group 1 No Smoothie

This group will make no changes to their pre-operative diet and will not consume the smoothie leading up to their TKA revision surgery.

experimental: Group 2 Smoothie

This group will receive the "Green Smoothie Guide" from the American College of Lifestyle Medicine which they will use to prepare a daily smoothie for the 14 days leading up to their total knee arthroplasty revision surgery. No other changes will be made to their pre-operative diet.

Interventions

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 measure

  • Feasibility Measured in Terms of Compliance [ Time Frame: Daily for 14 days pre-operative ]
  • Feasibility Measured in Terms of Noted Barriers/Facilitators [ Time Frame: Day 0 ]
  • Feasibility Measured in Terms of Satisfaction with Diet [ Time Frame: Baseline and 6 weeks post-operative ]

Central Contacts and Locations

Central contacts

Mia Zonies, BS

646-714-6849zoniesm@hss.edu

Pa Thor, PhD

646-797-8535thorp@hss.edu

Locations

HSS Main Hospital

Recruiting

New York, New York, United States, 10021

Contacts

Mia Zonies

646-714-6849zoniesm@hss.edu

More Information

Sponsor

Hospital for Special Surgery, New York

Last update posted

Jul 15, 2026

Last verified

Jul, 2026

Keywords

  • TKA Revision
  • Inflammation
  • Diet
  • Gut Microbiome

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Hospital for Special Surgery, New York on 2026-07-15.