Iontophoresis for Tennis Elbow
Abstract & Commentary
Synopsis: Iontophoresis was more effective than placebo in relieving tennis elbow symptoms in the short term.
Source: Nirschl RP, et al. Iontophoretic administration of dexamethasone sodium phosphate for acute epicondylitis: A randomized, double-blinded, placebo-controlled study. Am J Sports Med. 2003;31(2):189-195.
Lateral epicondylitis (tennis elbow) and medial epicondylitis (golfer’s elbow) are common complaints for both working and athletically active adults. Inflammation at the common tendon origin due to overuse can lead to degenerative changes, tendinosis, microtears, and amorphous fibrous tissue. Although surgery can be effective at relieving symptoms, there is a high recurrence rate of at least 15%. Therefore, non-operative methods for treatment continue to be explored. Iontophoresis is a method to deliver steroid locally with the assistance of a small, external electric current to drive water-soluble drugs through the skin to the target area. Locally high concentrations of drug can be achieved with few systemic side effects.
Nirschl and colleagues performed a randomized, double-blinded, placebo-controlled study of 199 patients with either medial or lateral epicondylitis. Patients received either active drug or placebo on 6 separate occasions 1-3 days apart for a 15-day period of time. They found that the active treatment group that received dexamethasone improved significantly on visual analogue scale ratings (23-mm improvement compared to 14 mm for placebo). The improvement was most notable in the short term with differences becoming less distinct at 1-month follow-up. Other primary variables measured included an investigator’s global evaluation scale and a patient’s global evaluation scale, both of which were significantly improved for the treatment group in the short term.
Secondary variables included assessment by the investigator of the patient’s level of severity. All measures showed improvement for the treatment group regarding pain, tenderness, and assessment of disease severity. Again, differences were more pronounced at short-term follow-up with less distinction at 1 month from treatment. Nirschl et al found on more careful analysis of their data that those patients who received their 6 treatments over fewer total days tended to have more pronounced improvements. Their conclusion was that iontophoresis with dexamethasone was both safe and effective, especially if treatments are condensed over fewer days (10 days or fewer).
Comment by David R. Diduch, MS, MD
Tennis elbow or golfer’s elbow are very common complaints. Repetitive activities are often the inciting event, but continued use in the work or home environment perpetuates the process. Surgery can be effective but has a high recurrence rate so is often avoided until nonoperative measures have failed. This paper is by Robert Nirschl, probably the leading authority on tennis elbow surgery, and other authors in a multicenter study that was IRB approved and extremely well designed. That the champions for surgery of tennis elbow are presenting this nonoperative treatment underscores the importance of treating these patients without surgery initially.
They found that iontophoresis with dexamethasone was indeed effective. The placebo-controlled, double-blinded design of the study adds credibility to their findings. They were very astute to analyze their data more carefully and determine that condensing the treatments over fewer days was more effective. Although the differences between treatment and control groups were less distinct with longer follow-up, Nirschl et al are encouraged to perform further studies with a more condensed administration of the drug and the addition of therapeutic exercises. None of these patients underwent physical therapy or other modalities to keep the study design as clean as possible. It is likely that in combination we will see even more pronounced effects.
It is also important to note that iontophoresis was found to be a very safe drug delivery method. This provides local delivery of a relatively high concentration of agent without many of the side effects, such as subcutaneous fat necrosis, skin depigmentation, and pain associated with steroid injections. Studies like this that validate safe, effective, nonoperative treatment for common problems are a welcome addition to the literature.
Dr. Diduch is Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA