Flex Appeal: Evaluating the Efficacy of Anesthetic Techniques for Manipulation of Knees Under Anesthesia

Flex Appeal: A Prospective Randomized Controlled Trial Evaluating the Efficacy of Anesthetic Techniques for Manipulation of Knees Under Anesthesia (MUA)

The purpose of this study is to determine if changing the type of anesthesia improves the outcomes of manipulation and pain control after the procedure. The study will compare a spinal anesthesia with a general anesthesia, to see if there is a better outcome from either anesthesia type.

Study Overview

• Status: Recruiting
• Conditions: Knee Stiffness After Total Knee Arthroplasty
• Intervention / Treatment: Procedure: Spinal Anesthesia; Drug: Chloroprocaine; Procedure: General Anesthesia; Drug: Propofol

• Study Type: Interventional
• Enrollment (Estimated): 128
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Durham, North Carolina, United States, 27705
      • Recruiting
      • Duke University Health System
      • Contact: Emily Hall, MD; Phone Number: 919-681-0880; Email: ezb2@duke.edu
      • Principal Investigator: Emily Hall, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion:

1. Patients ≥18 years presenting for a manipulation of knee joint under anesthesia.
2. ASA Classification I - III.
3. English speaking patients.

Exclusion:

1. ASA 4 or 5
2. Daily chronic opioid use (over 3 months of continuous opioid use).
3. Inability to communicate pain scores or need for analgesia.
4. Infection at the site of block placement
5. Age under 18 years old or greater than 75 years old
6. Pregnant women (as determined by point-of-care serum bHCG)
7. Intolerance/allergy to local anesthetics
8. Weight <50 kg
9. Suspected, or known addiction to or abuse of illicit drug(s), prescription medicine(s), or alcohol within the past 2 years.
10. Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in the opinion of the investigator, may interfere with study assessments or compliance.
11. Current or historical evidence of any clinically significant disease or condition that, in the opinion of the investigator, may increase the risk of surgery or complicate the subject's postoperative course.
12. BMI >50 kg/m2.

13. Allergy or contraindication to local anesthetics or any component of the multimodal analgesic regimen

    (NSAIDs and acetaminophen)

14. Contraindication to spinal injection

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Spinal Anesthesia; Patients receive spinal anesthesia during MUA (manipulation under anesthesia).	Procedure: Spinal Anesthesia; Administration of spinal anesthesia for knee manipulation.; Drug: Chloroprocaine; Patients undergoing spinal anesthesia will receive a spinal injection under standard aseptic technique, with 45mg chloroprocaine.
Active Comparator: General Anesthesia; Patients receive general anesthesia during MUA (manipulation under anesthesia).	Procedure: General Anesthesia; Administration of general anesthesia for knee manipulation.; Drug: Propofol; Patients undergoing general anesthesia will receive an induction dose of propofol that will be titrated to effect, and airway support as needed until the patient is appropriately anesthetized for the procedure as determined by the anesthesia and surgical care teams.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in degrees of motion of the affected knee	At time of procedure completion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pain	Participants will be asked to rate pain on a scale of 0-10 with 0 being no pain and 10 being the worst possible pain.	Baseline, 24 hours, 48 hours, 72 hours post-procedure
Opioid use in PACU		Day 3

Collaborators and Investigators

• Sponsor: Duke University
• Investigators: Principal Investigator: Emily Hall, Duke University

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: January 14, 2026
• First Submitted That Met QC Criteria: January 15, 2026
• First Posted (Actual): January 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: general anesthesia; spinal anesthesia; knee arthroplasty
• Additional Relevant MeSH Terms: Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Phenols; Benzene Derivatives; Anesthesia and Analgesia; Anesthesia, Conduction; Anesthesia; Propofol; Anesthesia, Spinal; Anesthesia, General; chloroprocaine
• Other Study ID Numbers: Pro00118605

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No