An interventional study of Assigned Interventions in Total Knee Arthroplasty Revision, Inflammatory Markers and Gut Microbiota, sponsored by Hospital for Special Surgery, New York. Recruiting at 1 site in United States. Open to participants aged 40 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-28.
Sponsored by Hospital for Special Surgery, New York · Not applicable, Interventional, and Other
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:
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.
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:
Participants will be randomly assigned to consume the whole food plant-based smoothie intervention daily for the two weeks leading up to surgery, or to have no preoperative diet intervention (control group).
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.
3,536 studies on the registry are indexed under Inflammation; 642 are open to participants now.
This study's planned enrollment of 24 is below the median of 50 across 2,577 interventional studies indexed under Inflammation.
Browse Inflammation studies →Hospital for Special Surgery, New York is the lead sponsor of 226 studies on the registry; 40 are open to participants now.
Of its 30 completed or terminated interventional studies of FDA-regulated products, 22 (73%) have results posted.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Sep 28, 2026. See what changed
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This group will make no changes to their pre-operative diet and will not consume the smoothie leading up to their TKA revision surgery.
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.
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.
Feasibility Measured in Terms of Compliance
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.
Time frame: Daily for 14 days pre-operative
Feasibility Measured in Terms of Noted Barriers/Facilitators
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.
Time frame: Day 0
Feasibility Measured in Terms of Satisfaction with Diet
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.
Time frame: Baseline and 6 weeks post-operative
Inflammation and Pain Control: C-Reactive Protein
Inflammation and pain control are quantified by biological markers of inflammation such as C-reactive protein found in the blood. C-reactive protein is produced in the liver, and its levels rise in response to inflammation. A normal range of C-reactive protein is less than 0.3mg/dL and is a more favorable outcome than an elevated level of C-reactive protein.
Time frame: Baseline, Day 0, Day 1, Day 2, Day 3, 6 weeks post-op
Inflammation and Pain Control: Interleukin 6
Inflammation and pain control are quantified by biological markers of inflammation such as the pro-inflammatory cytokine, interleukin 6, found in the blood. An elevated amount of Interleukin 6, above 15pg/mL, is indicative of increased inflammatory response in the body and is less favorable outcome.
Time frame: Baseline, Day 0, Day 1, Day 2, Day 3, 6 weeks post-op
Inflammation and Pain Control: Microbiome Composition
Inflammation and pain control are quantified firstly by biological markers of inflammation such as microbiome composition. Participants will complete three self-administered stool sample collections and ship their samples to Mount Sinai Laboratory. Mount Sinai will conduct raw 16S rRNA sequencing to show alpha and beta bacteria diversity. Higher diversity 4 days pre-op and 2 days pre-op relative to baseline is indicative of a more successful intervention and a more favorable outcome.
Time frame: Baseline, 4 Days Pre-op, 2 Days Pre-op
Inflammation and Pain Control- Numerical Rating Scales
Inflammation and pain control are quantified firstly by markers of acute pain/analgesia which are measured by Numerical Rating Scales (NRS) of pain. Participants will be asked questions about their knee pain on a scale of 0-10 where higher scores are indicative of increased pain and a less favorable outcome.
Time frame: Baseline, Day 0, Day 1, Day 2, Day 3, 6 weeks post-op
Inflammation and Pain Control: Opioid Intake
Inflammation and pain control are quantified by markers of acute pain/analgesia such as opioid intake. Opioid intake will be recorded from participants' medical charts while they are under care at HSS Main Hospital. Opioid intake will be measured in morphine milligram equivalents (MME) with a lower opioid intake being more favorable.
Time frame: Postoperatively; 0-24 hours, 24-48 hours, and 48-72 hours
Diet Quantification
Diet will be quantified using Diet ID Inc.'s online software, a validated tool, which measures diet quality, caloric intake, and nutrient intake. After participants go through the Diet ID survey, the Diet ID platform will calculate a "Nutrition Score" which will be the recorded value of nutrition. The scores will be reported on a scale of 1-10 with higher scores indicating "better" nutrition and a more favorable outcome.
Time frame: Baseline, Day 0, and 6 weeks post-op.
BIA Measurements: Phase Angle
Bioelectrical Impedance Analysis (BIA) produces a measurement of phase angle (PhA) which measures the water distribution among intracellular and extracellular space. Phase angle is measured in degrees with 6.5-7.5 degrees being described as a healthy range and lower degrees being less favorable.
Time frame: Baseline, Day 0, and 6 weeks post-op.
BIA Measurements: Fat-Free Mass (Index)
Bioelectrical Impedance Analysis (BIA) produces a measurement of fat-free mass (FFM) which is a measurement of the total body weight excluding fat. BIA testing produces a fat-free mass weight in kg which is divided by the total kg of the participant to produce a percentage of fat-free mass. For men, a healthy range for a fat-free mass percentage is \~78%-87%, and for women, a healthy range is \~67%-75%. The fat-free mass index measurement can also be calculated using the measurement of fat-free mass relative to height.
Time frame: Baseline, Day 0, and 6 weeks post-op.
BIA Measurements: Extracellular Water
Bioelectrical Impedance Analysis (BIA) can produce measurements of extracellular water (ECW) which is the water outside of the cells.
Time frame: Baseline, Day 0, and 6 weeks post-op.
BIA Measurements: Extracellular Water, Total Body Water, and Ratio ECW/TBW
Bioelectrical Impedance Analysis (BIA) can produce measurements of Extracellular Water (ECW)--the fluid outside of the cells--and Total Body Water (TBW). Then, a ratio of extracellular water to total body water (ECW/TBW) can be calculated with a normal range for this ratio being 0.360-0.390. A higher value for this ratio is indicative of a less favorable outcome.
Time frame: Baseline, Day 0, and 6 weeks post-op.
PROMIS-Global 10
The PROMIS-Global 10 is a validated 10-item questionnaire to evaluate health in relation to quality of life. Questions are rated on a scale of 1-5 with a higher score being indicative of higher health and a more favorable outcome. Scores for all questions will be added up to calculate a total score.
Time frame: Baseline, Day 0, 6 weeks post-op, and 6 months post-op.
Range of Motion
Angle of knee movement in degrees as recorded during all standard of care visits. Measurement points include: the internist physician during pre-surgical screening, the surgeon on Day 0, physical therapy on Days 1-3, the surgeon during the 6-week post-operative follow-up visit.
Time frame: Baseline, Day 0, Day 1, Day 2, Day 3, 6 weeks post-op
Frailty
The 5-Item frailty index is a standardized, comorbidity-based risk stratification tool used to predict adverse events.
Time frame: Baseline
Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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