Effectiveness of Radial Extracorporeal Shockwave Therapy on Tennis Elbow

Background: Tennis elbow, also known as lateral epicondylitis, is the inflammatory status of insertion site of common extensor tendon to humerus. It is usually related to overuse of local muscle. Radial extracorporeal shock wave therapy (rESWT) is a non-invasive physical treatment. It applies shockwave energy to the lesion site, enhancing the growth of microvascularity, inducing tissue repair, and thus relieving the symptom. The purpose of this study is to understand the therapeutic effect of rESWT to tennis elbow. Material and Methods Subjects: 30 patients will be recruited from outpatient department of physical medicine and rehabilitation department. Duration: 2013.09.01-2015.05.31 Methods: The patients will be randomly divided into the experimental group and the control group through the draw, with 15 patients in each group. Patients in the experimental group receive rESWT plus routine rehabilitation program. Patients in the control group receive sham shockwave therapy plus routine rehabilitation program. Assessment: Before the therapy starts, patients who match the inclusion criteria will be evaluated using tools mentioned below: General data: age, sex, body height, body weight, affected side, medical history Assess upper extremity function and symptom with Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH) Assess severity of pain with Visual Analogue Scale (VAS) Assess grip strength with grip strength dynamometer Measure the size of tear (if any) of common extensor tendon through ultrasonography, and assess the texture of common extensor tendon through real-time sonoelastography (RTS) Patients will be followed up 6 weeks, 3months, and 6 months after therapy starts. They will be re-assessed of upper extremity function and symptom, severity of pain, grip strength, and presentation on ultrasonography and RTS.

lateral epicondylosis, lateral epicondylitis, shockwave, sonoelastography, tennis elbow, pain intensity, grip strength, upper limb function, stiffness of common extensor tendon

Participants in the experimental group received radial extracorporeal shock wave therapy (rESWT) plus physical therapy for 3 weeks.

Each participant in the experimental group received rESWT for 3 sessions, consisting of 2000 impulses for each session, and one session per week over 3 weeks (a total of 6000 shock waves were given). The pneumatic pressure was set at the maximum level tolerable for each patient. The frequency of pulses was set at 10 Hz.

Sham shockwave therapy were given by the same physiatrist using the same machine as the experimental group, with the same rESWT protocol (3 sessions, 2000 impulses for each session, one session per week over 3 weeks) and the same frequency (10 Hz) of impulses, but the pneumatic pressure was set at 0.1 bar, with a similar sound to the regular rESWT but without actual energy conduction.

The physical therapy program was performed 3 times a week over the same 3 weeks as rESWT, and consisted of 5 minutes of ultrasound diathermy, 15 minutes of transcutaneous electrical nerve stimulation (TENS), and 10 minutes of therapeutic exercise, including wrist common extensor stretching and self-massage.

Participants were asked to rate their present pain intensity, as caused by the tennis elbow, from 0-10 using the Visual Analogue Scale (VAS). If participants had bilateral tennis elbow, the side with the worse pain intensity was chosen for the assessment.

Maximal grip strength of the involved arm was assessed using a grip strength dynamometer. Participants were asked to grip the dynamometer 3 times, at 15- second rest intervals, and the highest grip strength number was recorded.

Upper extremity disability and symptoms were assessed using the Taiwan version Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire.

The changes in stiffness of common extensor tendon were assessed with sonoelastography. The images of sonoelastography were interpreted with the modified RTS scoring system and analyzed with color histogram.

On the 2-D image, the common extensor tendon was located. If there was tear within common extensor tendon, diameters in the 3-D dimension were measured and the size of the tear was calculated as a spheroid.

Inclusion Criteria: Aged > 18 years old Lateral elbow pain lasting > 3 months Pain induced by direct compression on the lateral epicondyle or common extensor tendon, resistant wrist extension and pronation in the elbow extension position, or static stretching of common extensor tendon through the palmer flexion in wrist pronation and elbow extension position Exclusion Criteria: Generalized inflammatory arthritis (e.g., rheumatic arthritis) Pain at the proximal part of involved arm (e.g., shoulder pain, neck pain) Pain other than elbow pain at the involved arm Abnormal neurogenic symptom over the involved arm (e.g., radicular pain, hands numbness, hemiplegia) Wound or skin lesion at the elbow of the involved arm Pregnancy Severe local or systemic infection Malignancy Coagulopathy Cardiac pacemaker History of surgical treatment at the elbow of the involved arm Non-steroid anti-inflammatory drug (NSAID) use orally or topically at the elbow of the involved arm in the past week Local steroid injection at the elbow of the involved arm in the past 3 months Oral steroid use in the past 6 weeks Refusal to sign the informed consent Impairment in self-expression (e.g., dementia, aphasia) Inability/unwillingness to participate in all the measurements.

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