Review Question - QID 218600

A 13-year-old male baseball pitcher presents to your office for evaluation decreasing elbow motion for the past 12 months. He also complains of vague joint pain in several other joints. He denies any specific injury to the elbow as well as any discomfort with activities. Physical examination reveals a loss of extension of 30 degrees compared with the contralateral elbow without tenderness anywhere about the elbow. An MR arthrogram of the elbow reveals lesions in the radial head, proximal ulna, and capitellum, as well as squaring off of the capitellum. Which of the following is the first line of treatment for this patient's painless elbow loss of motion?