Knee Flexionater to Avoid Motion Restoring Surgery

Summary

The goal of this clinical trial is to learn whether adding a stretching device to standard physical therapy can help people regain knee bending after total knee replacement surgery.

Some people have difficulty bending their knee during recovery. When this happens, doctors may recommend another procedure called motion-restoring surgery to improve knee movement.

This study aims to answer two main questions. First, does adding a hydraulic high-intensity stretching device to physical therapy help people regain knee bending after surgery? Second, does using the device affect recovery, daily activities, or the chance of needing another procedure?

Researchers will compare two treatment approaches. One group will receive standard physical therapy alone. The other group will receive standard physical therapy and will also use a hydraulic high-intensity stretching device called the Ermi Knee Flexionater at home.

Participants who receive the device will use it at home each day in addition to attending their physical therapy sessions. Researchers will measure how well participants can bend their knee and will ask questions about pain, daily function, and activity level. Participants will also complete simple walking and mobility tests.

Study visits will occur about four weeks after surgery when participants enroll, and again at about eight weeks, twelve weeks, six months, one year, and two years after surgery. Researchers will compare results between the two groups to see whether the stretching device improves recovery after knee replacement.

Conditions

• Joint Contractures
• Total Knee Anthroplasty
• Knee Arthrofibrosis

Interventions

DEVICE

Hydraulic high Intensity Stretch Device

A hydraulic high-intensity mechanical stretch device (Ermi Knee Flexionater) used as an adjunct to standard postoperative physical therapy following primary total knee arthroplasty. The device is designed to apply controlled, patient-actuated stretch to increase knee flexion range of motion. Participants assigned to this intervention will use the device at home daily for approximately one hour, in addition to attending prescribed physical therapy sessions. Device use will begin at approximately four weeks postoperatively and continue for up to eight weeks, consistent with the study protocol. Participants will receive in-person instruction on device setup and operation and will record frequency and duration of use in a log. Compliance will be monitored through weekly check-ins.

OTHER

Standard Physical Therapy

Supervised postoperative physical therapy following primary total knee arthroplasty. Therapy includes range of motion exercises, strengthening, neuromuscular re-education, manual therapy, and functional rehabilitation as determined by the treating clinician.

Sponsors & Collaborators

• Ermi LLC

  lead INDUSTRY

Principal Investigators

• Shaun K Stinton, PhD · Ermi LLC

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

40 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-12-09

Primary Completion

2029-12-31

Completion

2029-12-31

FDA Device

Yes

Countries

• United States

Study Locations