Does acetic acid iontophoresis accelerate the resorption of calcium deposits in calcific tendinitis of the shoulder?

A 48-year-old man, who was otherwise in good health, developed pain and a “clicking” sensation in his right shoulder during movement. The patient, who was referred to me by his physician, stated that this problem began approximately 2 months ago and has been getting steadily worse ever since. The patient is an avid skier and tennis player; however, he did not recall any serious direct trauma to the shoulder. Shoulder passive range of motion (ROM), measured using standard goniometric techniques as discussed by Riddle et al,1 was 0 to 170 degrees for flexion, 0 to 165 degrees for abduction, 0 to 70 degrees for internal rotation, and 0 to 75 degrees for external rotation. Manual muscle testing did not reveal any major strength deficits in the shoulder musculature, with the primary muscle groups graded between 4+ and 5 on scale of 0 to 5. Active humeral abduction, however, resulted in pain, especially near the midpoint of shoulder abduction. Radiographs that had been ordered by the physician showed a calcium deposit in the tendon of the right supraspinatus muscle. This deposit was approximately 175 mm2 in area, had well-defined borders, and was uniformly dense throughout the lesion. This patient, therefore, appeared to have calcific tendinitis of the right supraspinatus muscle.