A Pilot Feasibility Study of IM OXT on Fear of Pain and Trust in Physical Therapist During OP Rehabilitation After TKA

What Was Tested

This registered phase 2 trial tested Oxytocin.

Investigators will ask participants to answer questions about fear of pain and movement before several outpatient physical therapy session and investigators will ask participants questions about trust of the physical therapist several times after the outpatient physical therapy sessions.

It had two arms (groups): Oxytocin (experimental) and Placebo (active comparator).

Oxytocin IM injection will be given per randomization prior to first outpatient physical therapy session.

Placebo IM injection will be given per randomization prior to first outpatient physical therapy session.

The registry classes the interventions as drug.

More on the Plan

The purpose of this study is to determine feasibility of this study design and identify barriers that altered design could bring to overcome these barriers in the design of a large, pragmatic, multi-center clinical trial.

It is also designed to estimate the effect size and variance of the main outcome measures, trust and fear, in patients undergoing rehabilitation after total knee arthroplasty (TKA).

Again, the study is not designed to test this hypothesis, but to gather the critical data necessary to test it in a large, multi-center clinical trial that would follow this grant.

Participants that have decided to undergo unilateral TKA, will come to the Pain Clinical Research Unit at least 48 hours prior to surgery to confirm consent and complete a series of questionnaires.

Who Took Part

It was open to people of any sex aged from 18 years up to 75 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Male or female \> 18 and \< 75 years of age, Body Mass Index (BMI) \<40.

The full record lists 4 inclusion and 4 exclusion criteria; among the exclusions: subjects with neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.

How the Study Was Run

It was run as a randomized, parallel-group and triple-blind study.

The participants were allocated by chance, so the Oxytocin group and the comparison group should start out alike.

The Oxytocin group and the comparison group ran side by side rather than switching.

As a double-blind Oxytocin study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, investigator and outcomes assessor.

It started in 2024-01 with completion listed for 2026-01.

It ran at 1 site in United States.

Its stated primary purpose is basic science.

What Was Measured

Researchers chose this as the main measure: Tampa Scale of Kinesiophobia-11 (TSK-11) (time frame: Postoperative Outpatient Physical Therapy Visit 1/study medication administration visit/Baseline). Tampa Scale of Kinesiophobia-11 (TSK-11) (time frame: Postoperative Outpatient Physical Therapy Visit 2, 1-5 days after study medication). Tampa Scale of Kinesiophobia-11 (TSK-11) (time frame: Postoperative Outpatient Physical Therapy Visit 4, 5-10 days after study medication).

It also tracked 6 secondary outcomes, for example Pain during straight leg raise, Pain after straight leg raise, Physical therapist deems stepping exercise begins; may walk up and down steps, Gait speed, Average pain score and Analgesic Consumption.

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Oxytocin in people.

It was withdrawn before enrolling anyone; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Oxytocin compound page, all human trials.