Trio of tennis elbow studies detail treatment, causation possibilities

Researchers find platelet injections reduce pain and corticosteroids have high regression rates.

Issue: February 2007

Within the past 6 months, investigations in three separate trials have published differing data on prevention and treatment of tennis elbow.

Allan Mishra, MD [photo]
Allan Mishra

Allan Mishra, MD, and colleagues at the Stanford University Medical Center, may have found a way to treat tennis elbow in chronic sufferers without surgery.

In a prospective pilot study researchers found that a one-time injection using the patient's platelets reduced pain and allowed return to activity. The investigators' work was published in the American Journal of Sports Medicine.

This was the first in vivo human investigation of this biologic treatment for chronic elbow tendonitis for patients who have "flunked out of other treatments," Mishra told Orthopedics Today.

In a news release, Mishra added, "There is very little risk here. We are using the patient's own blood taken right in the doctors office, and the whole procedure takes less than an hour. The results of our pilot study indicate this therapy is as effective as surgery, with sustained and significant improvement over time, no side effects and high patient acceptance."

Injecting a patient’s platelets into an elbow
Allan Mishra, MD, injects a patient’s platelets into an elbow for treatment of chronic elbow tendonitis.

Image: Mishra A

At 6 months post-treatment, analog scores for patients treated with platelet-rich plasma improved 81%, and at a 2 year evaluation, 93% of patients reported "complete satisfaction," according to the release. The other 7% were "partially satisfied."

Australian study

Researchers in Brisbane, Australia, compared movement and exercise, corticosteroid injection and wait-and-see methods for the treatment of tennis elbow. Their investigation appeared in the British Medical Journal.

It involved 198 patients, from 18 to 65 years of age, with a clinical diagnosis of tennis elbow, with a minimum duration of 6 weeks, who had not received any other treatment in the previous 6 months.

The researchers randomized the patients into three groups, each receiving eight sessions of physiotherapy, corticosteroid injections or no treatment.

Corticosteroids

Leanne Bisset, a PhD candidate, and colleagues found that corticosteroid injections provided significantly better results at 6 weeks, but showed subsequently higher recurrence rates (47 of 65 successes regressed) and poorer outcomes in the long term compared with physiotherapy.

According to a news release, participants who had physiotherapy sought less additional treatment than participants in the wait-and-see group.

Racket grip size

George F. Hatch III, MD, and colleagues in Los Angeles found that a tennis racket's grip size does not factor into the development of tennis elbow. Instead they believe it results from repetitive impact of the ball and racket, along with poor wrist stability, specifically during a backhand swing. Their research was published in the American Journal of Sports Medicine.

"Based on our data, we recommend recreational tennis players use the currently accepted grip size measurement technique as a starting point when picking a grip size," Hatch noted in a press release. "However, the player should feel free to increase or decrease the size of the grip based on what feels most comfortable."

Measuring muscle responses

The investigators studied 16 (10 men, six women) NCAA Division I and II tennis players with no history of elbow problems. Players' recommended grip size was determined by measuring the distance from the bottom lengthwise crease in the palm to the tip of the ring finger with a ruler.

Researchers inserted electrodes into five muscles in each patient's dominant arm to measure the firing pattern of their muscles via an electromyelogram (EMG).

After warming up, each participant executed three single-handed backhand strokes using identical rackets with three different grip sizes: the recommended grip size; a small grip size, 1/4 inch smaller than recommended; and a large grip size, 1/4 inch larger than recommended.

Each stroke was recorded on high-speed video, and then synchronized with the corresponding EMG. The 1/4-inch variations were chosen because most commercially available rackets' grip sizes range from 4 inches to 4 5/8 inches.

Of the muscles studied, none showed significant variation in firing patterns, the researchers reported in the press release.

They paid close attention to the extensor carpi radialis brevis and the extensor digitorium communis, which are located next to each other and originate from the outside of the elbow.

Overuse, microtrauma and failed healing in these muscles can result in tendonitis; however, grip size did not affect the muscles' activities, according to the researchers.

For more information:
Beller E, Bisset L, Jull G, et al. Mobilisation with movement and exercise, corticosteroid injection, or wait and see for tennis elbow: randomised trial. BMJ. 2006;333(7575):939.
Hatch GF, Mohr KJ, Pink MM, et al. The effect of tennis racket grip size on forearm muscle firing patterns. Am J Sports Med. 2006;34(12):1977-1983.
Mishra A, Pavelko T. Treatment of chronic elbow tendinosis with buffered platelet-rich plasma. Am J Sports Med. 2006; 34:1774-1778.
Leanne Bisset teaches musculoskeletal physiotherapy and orthopaedics at the School of Physiotherapy and Exercise Science, Griffith University, G02 - Room 1.14, Parklands Drive, Southport, Queensland, Australia; +61-7-5552-7717; l.bisset@griffith.edu.au. George F. Hatch III, MD, department of orthopaedic surgery at University of Southern California Keck School of Medicine, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033; 323-442-5860; lhatch_2000@yahoo.com. Allan Mishra, MD, Menlo Medical Clinic, Stanford University Medical Center, 1300 Crane Street, Menlo Park, CA 94025; 650-724-8000.