Metabolomic Profiling of Patients Undergoing Total Knee Arthroplasty


About this study

The purpose of this study is to gather initial data for pain biomarker discovery in humans with correlation to clinical outcomes. Additionally, the study will test the hypothesis that the analgesic mechanism of acetaminophen in humans relies on the serotonergic and endocannabinoid system. 

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  1. Patients will be undergoing elective cases of total knee arthroplasty under spinal anesthesia. Patients must be ASA I-III
  2. Non-pregnant and 18 years of age and over.  

Exclusion Criteria:

  1. Patients who are unable to take acetaminophen as part of their analgesic regimen due to:
    1. Severe hepatic insufficiency (Child-Pugh Score B or C)
    2. Allergy to acetaminophen
  2. Patients who have a history or risk of gastric emptying:
    1. Diabetic patients
    2. Gastroparesis
  3. Patients on anti-coagulation therapy where neuroaxial anesthesia is contraindicated as per American Society of Regional Anesthesia (ASRA) guidelines
  4. Patients with significant history of lumbar spinal surgeries or lumbar scoliosis where spinal anesthesia would be difficult to perform
  5. Medical conditions which precluded use of regional anesthesia
  6. Chronic pain with opioid usage over 100 mg morphine equivalents orally daily
  7. Documented rheumatoid arthritis
  8. History of abuse of opioids
  9. Patients scheduled for bilateral TKA
  10. Patients scheduled for a TKA revision

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Jacksonville, Fla.

Mayo Clinic principal investigator

Steven Clendenen, M.D.

Closed for enrollment

Contact information:

Steven Clendenen M.D.

(904) 956-3327

More information


Publications are currently not available

Study Results Summary

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Supplemental Study Information

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