Corticosteroid and Lidocain Injections for Tennis Elbow

The investigators hypothesized that lidocain injection is as effective as corticosteroid injection in management of tennis elbow, and if so, it may replace corticosteroid injection in the management of tennis elbow.

Lateral epicondylitis or tennis elbow is a tendinopathy of the common extensor origin of the lateral elbow, and is estimated to have an annual incidence of 1-3%. It is characterized by tenderness over the lateral epicondyle of the humerus, normal range of motion, and pain on resisted extension of the wrist or fingers. Symptoms can persist for between 6 months and 2 years but usually resolve within 12 months. Although tennis elbow is often self-limited, around 20% of cases are refractory to conservative care. Tennis elbow is now thought to be non-inflammatory, and the pathologies are characterized by collagen degeneration, fibroblast proliferation, mucoid degeneration, and neovascularization. Treatment of tennis elbow includes relative rest, physical therapy (therapeutic exercise, massage, therapeutic ultrasound, lower power laser, etc.), analgesics, non-steroidal anti-inflammatory drugs, glyceryl trinitrate patches, injection therapy (corticosteroid, hyaluronan gel, botulinum toxin, and autologous platelet-rich plasma), shock wave therapy, and even surgery. Previous studies showed corticosteroid injection is effective in the short term, but is harmful in the long-term, and is more likely to have a recurrence. In consideration of a degenerative lesion in tennis elbow, corticosteroid injection may be not an ideal agent. Although plate-rich plasma injection showed promising results, the high cost limited its widespread clinical use. Since local lidocain injection is commonly used in the management of myofascial pain syndrome, it might be effective in the treatment of tendinopathy like tennis elbow. The purpose of this study is to compare the effect of corticosteroid injection and lidocain injection in the treatment of tennis elbow. The investigators hypothesized that lidocain injection is as effective as corticosteroid injection in management of tennis elbow, and if so, it may replace corticosteroid injection in the management of tennis elbow.

For corticosteroid injection, triamcinolone (10mg/ml) 1 ml will be injected to the lateral epicondyle of the affected elbow.

The primary outcome measure is the change in the composite score on the Patient-Rated Tennis Elbow Evaluation (PRTEE), which is a tennis elbow-specific questionnaire evaluating disease-specific quality of life. PRTEE includes a 5-item pain scale, with o indicating no pain and 10 indicating the worst pain imaginable; a 10-item functional disability scale, with 0 indicating no difficulty and 10 indicating greatest difficulty (unable to do). The scores range from 0 (good quality-of- life, no pain or disability) to 100 (poor-quality of-life, extremes pain and disability).

The grip strength is a commonly used objective measure of tennis elbow-related disability, with good test-retest (Pearson correlation, r≥0.80) and validity (±3%) measures. The participants will sit in a chair with their shoulder flexed at 90 degrees, their elbows extended, and their forearms in neutral position. All participants are instructed to squeeze the dynamometer and cease squeezing before the onset of pain. The mean of the three replications will be recorded, with each measure separated by 60-sec interval.

Another secondary outcome measure is ultrasound assessments of common extensor tendons at elbow, using published ordinary scales for hypoechogenecity, tendon thickness, and neovascularity, which have been reported to be associated tendinopathy.

Treatment satisfaction included patient's rating of the treatment outcome, using a 5-point(0, very dissatisfied; 5 very satisfied) scale.

Inclusion Criteria: Between 20 and 75 years of age, with lateral elbow pain ≥4 in pain VAS for at least 1 month Reproducibility of pain by 2 or more of the following tests: palpation of the lateral epicondyle and/or the common extensor origin of the elbow; resisted wrist extension (dorsiflexion) and pronation with the elbow in extension Pain reproduced by static stretching of the pronated wrist in palmar flexion with the elbow in extension. Exclusion Criteria: not fulfill inclusion criteria