The purpose of this study is to measure the effectiveness of a wearable therapeutic ultrasound device in patients with stage I and stage II knee osteoarthritis. The ability of the device to reduce pain, increase mobility, increase range of motion and muscle strength of the affected leg, and improve quality of life in patients with knee osteoarthritis will be evaluated.

This is an eight week study to clinically evaluate the effect of the low intensity long duration ultrasound (LITUS) device on symptoms of patients suffering from knee osteoarthritis. The device, sam® has been FDA-cleared for use. For the first two weeks of the study, baseline data will be collected as patients report pain scores (NRS) three times per day. During the following 6 weeks, patients will self-apply the wearable LITUS device to their affected knee for 4 hours daily. Each day of the study, pain scores (NRS) will be recorded immediately before application of LITUS device as well as 30 minutes, 2-hours and 4-hours after applying the device. A quality of life assessment (WOMAC), muscle strength and range of motion assessment (JTech) will be performed prior to the patient beginning the protocol and at the conclusion of the protocol.

Up to 93 subjects will be recruited from neighboring communities to the study site. The study is designed to reach a target patient population which includes rural citizens and socioeconomic disadvantaged individuals where non-pharmacotherapies do not exist to manage pain. Subjects will be randomly assigned to active (60%) and placebo groups (40%). The sponsor and investigators are blinded as to which type of device each patient is assigned.

The study will be monitored by an external monitor and a data safety monitoring board (DSMB).

Inclusion Criteria:

• Physician-diagnosed mild to moderate knee osteoarthritis (OARSI atlas grades 1-2) based on fixed-flexion x-ray radiological findings for osteophytes and joint space narrowing within the past 12 months
• Fulfill the American College of Rheumatology clinical and radiological diagnostic criteria for knee OA
• 35-80 years of age
• Report a frequent pain score between 3-7 (NRS range: 0-10) during the week preceding enrollment
• Report that knee pain negatively affects quality of life
• Willing not to use any cream, gel, or topical solution during the administration of treatment other than the approved ultrasound gel provided to the subject at the initiation of the study
• Deemed appropriate by their physician or by the study site physician to participate

Exclusion Criteria:

• Cannot successfully demonstrate the ability to put on and take off the device
• Display any condition which, in the judgment of the investigator, would make participation in the study unacceptable, including, but not limited to, the subject's ability to understand and follow instructions.
• Have severe OA or have little to no cartilage in the knee
• Have knee replacement, other surgical intervention, or hyaluronidase injection in the affected knee in the past 6 months
• Are non-ambulatory
• Participated in a clinical trial for an investigational drug and/or agent within 30 days prior to screening
• Modify their medications during the course of the study (medications and doses must remain constant throughout the study)
• Currently taking steroids
• Have contraindication to radiograph
• Have a secondary cause of arthritis (metabolic or inflammatory)

8 weeks (study duration)

No adverse events (serious or non-serious) were observed. Patients were supplied with daily diaries where adverse reactions could be self reported. Additionally, follow-up appointments assessed for adverse reactions during weeks 1, 3 (baseline) and week 5, 7, 8 (intervention period).

Small number of patients enrolled in range of motion and strength study may have limited statistical analysis. Future studies should include larger sample sizes.