Multiple Platelet-Rich Plasma Lateral Epidondylitis Injections Versus a Single Platelet-Rich Plasma Injection

Is there greater clinical improvement in long term pain and function when patients receive
two PRP injections instead of one? This is a double-blinded randomized controlled study to
determine the ideal treatment regimen for treatment of chronic lateral epicondylitis (tennis
elbow). The investigators will compare pain visual analog scale (VAS) scores and functional
Disabilities of Arm, Shoulder, and Hand (DASH) Questionnaire scores of patients receiving a
single PRP injection and two PRP injections.

The study will be conducted at Kaiser Modesto Sports Medicine involving 532 patients who meet
strict criteria for chronic lateral epicondylitis (including greater than 2 months of chronic
lateral epicondylitis and failing at least one other treatment modality). Patients are
randomly divided between three groups: 234 patients will receive one PRP injection, 234 will
receive two, and 64 in the control group will receive a saline injection. All participants
will receive concurrent home based stretching and strengthening exercises. Results are to be
measured using the Visual Analog Scale (VAS) and Disabilities of Arm, Shoulder, and Hand
(DASH) Questionnaire on the initial and follow-up visits of 2, 6, and 12 months. Both
measures have been validated by prior studies. Successful treatment of lateral epicondylitis
will be defined as a 25% reduction in visual analog score VAS and DASH scores between initial
and 6 month visits. Average control and experimental groups VAS scores are expected to be 8
out of 10 with an improvement to 7 and 6 respectively in 6 months. Average control and
experimental group DASH scores are expected to be 49 with an improvement to 44 and 28
respectively in 6 months.

PRP is an effective treatment in reducing pain of chronic lateral epicondylitis. This study
aims to prove there is greater clinical improvement in long term pain and function when
patients receive two PRP injections instead of one.

Inclusion Criteria:

1. Lateral epicondylitis - diagnosed by orthopedic or sports medicine physicians / 2
separate examinations (examination at referral / confirmatory examination at time of
injection)

2. Pain at the lateral epicondyle on direct palpation

3. Pain with resistive wrist extension and/or supination

4. No clinical findings at annular ligament, radiocapitellar joint, or PIN (posterior
interosseous nerve syndrome)

5. No underlying bone pathology

6. Symptoms present for > 3 months

7. Visual analog score (VAS) that is >= 5/10

8. Last steroid injection > 3 months

9. Failed previous therapy (> = 4 weeks of strap, splint, cast, injection or any other
accepted therapy without satisfactory pain or function)

Exclusion Criteria:

1. Age < 18 years

2. Pregnant

3. Symptomatic Carpal Tunnel syndrome on the affected side

4. History of cervical radiculopathy

5. History of Diabetes Mellitus, Rheumatoid Arthritis, hepatitis

6. Blood disorder

7. No immunocompromised patients (Human ImmunoDeficiency Virus, cancer, immunomodulator
therapies)

8. Oral Nonsteroidal Antiinflammatory in the past 1 week or Steroid Drug use in the past
3 months

9. Participation in a workers' compensation program or planning to apply for the program
and/or any ongoing, pending, or planned legal action as a result of elbow pain