Arthroscopic Excision of Heterotopic Ossification in the Supraspinatus Muscle.

Heterotopic ossification is formation of bone in atypical extra-skeletal tissues and usually occurs spontaneously or following neurologic injury with unknown cause. We report a 46-year-old female with right shoulder pain and restricted range of motion (ROM) for 3 months without history of trauma. Magnetic resonance imaging (MRI) showed a lesion within the rotator cuff supraglenoid. Excisional biopsy from a previous institution revealed a heterotopic ossificans (HO ). Following repeat MRI and bone scan, histopathology from arthroscopic resection confirmed an HO. The patient demonstrated improved pain and ROM at follow-up. Idiopathic HO rarely occurs in the shoulder joint, and resection of HO should be delayed until maturation of the lesion to avoid recurrence. The current case showed that arthroscopic HO resection provides an excellent surgical view to ensure complete lesion removal and minimize soft tissue damage at the supraglenoid area. Furthermore, the minimally invasive procedure of arthroscopy may reduce rehabilitation time and facilitate early return to work.