PEAK Platelet-rich Plasma Injection Treatment for Chronic Lateral Epicondylitis (Tennis Elbow)

Current Projects | Research Study Details

medical illustration of joint

Posted on Aug 31, 2016 by the Sports, Ultrasound, MRI, Minimally Invasive Treatments (SUMMIT) Lab

Chronic patellar tendinopathy (PT) is a degenerative tendon condition resulting in knee pain, considerable long-term morbidity, and a sedentary lifestyle. Currently, there are no conservative treatments that directly address the underlying functional changes associated with degenerative tissue conditions. Results from other studies reported that platelet rich plasma (PRP) injection therapy for PT resulted in improved quality of life, decreased pain and increased function, and have the potential to modify the disease course at the level of the damaged tendon. These findings have resulted in increasingly common use of PRP in clinical practice. However, PRP has not been rigorously evaluated as a therapy for PT.

Acoustoelastography (AE) is an ultrasound based method developed to analyze the mechanical properties of tendons and ligaments. Currently, elastography is already being used to measure the “hardness” of tissue lesions in order to differentiate tumor from normal tissue. However, this new application is not being used for the musculoskeletal system, whereby tendons, muscles, and ligaments that exhibit changes during injury or chronic degenerative states could be assessed using a cost effective and safe imaging modality. It is hypothesized that acoustoelastography is able to measure these changes to differentiate disease-specific tissue states of tendons, ligaments, or patellar tendon. The AE method can add mechanical information to the conventional ultrasound exam.

The purpose of the study is to determine whether a platelet-rich plasma (PRP) injection improves patella tendon (kneecap tendon) pain. PRP is blood plasma that has been enriched with platelets, a type of blood cell that is a source of growth factors.  PRP is sometimes used as a treatment for tendon pain, but is not a proven therapy.  A second purpose is to determine whether acoustoelastography (AE) can measure changes in the tissue state of the patellar tendon.

 Study is Open through 2023


Adults between the ages of 16 and 65 years,
who have been diagnosed with chronic patellar tendonitis for at least 3 months,
and have tried other therapies for pain and symptom relief

What is Involved for Participants

If you decide to participate in this research you will first be asked some screening questions by the study team. If you are under 18, we will need to obtain permission from your parent or guardian to conduct the screening with you.  If you qualify, you will then be asked to schedule a brief physical examination of your knee to determine if you are eligible.  The person conducting the phone screen will schedule this appointment and it will be conducted at the Sports Medicine Clinic at Research Park. 

You will then be asked to come to the Wisconsin Institute for Medical Research, 1111 Highland Avenue, Madison, Wisconsin, to provide a blood sample, receive an injection and complete some pain questionnaires.  This visit will take approximately 60 minutes.  There will be two groups of people participating in this study. One group will be the test subjects and the other will be a control group. The study is blinded which means you will not know which group you are in. The person withdrawing your blood will not know which group you are in. If you are in the control group, you will receive 5 mL of saline solution. If you are in the test group, you will receive 5 mL of your own platelet-rich plasma.

You will also receive questionnaires which you will complete and return in the mail using provided addressed, stamped envelopes, four various times after the injection. It should take approximately 5-10 minutes to complete each of these questionnaire sessions. 

The last visit will take place 32 weeks after the injection and will include a follow-up ultrasound and you will be asked to complete the same 3 questionnaires.  This will last about 30 minutes.

Your participation will require approximately 2 hours in total.

For more information about this research study, please contact Jan Yakey, RN, CCRC, Senior Clinical Nurse Specialist at or call 0: (608) 265-3018

This study is part of the Sports, Ultrasound, MRI, Minimally Invasive Treatments (SUMMIT) Lab.


Learn more about the lab.