Medial Elbow Pain - Young Baseball Pitcher

Abstract

HISTORY: A 14-year, 2-month old male right-handed baseball pitcher presented with chronic right medial elbow pain over 18 months, with no inciting injury/trauma. Initially he had mild right medial epicondylitis on magnetic resonance imaging (MRI) which resolved with rest and physical therapy. Still his right elbow pain recurred when throwing, ultimately failing conservative measures. Our collaborating orthopaedist then referred him to us for ultrasound and nonsurgical management. At his initial visit with us, he reported no pain at rest. He last had elbow pain one month earlier while doing lighter outfield (non-pitching) throws. PHYSICAL EXAMINATION: Afebrile with normal blood pressure and pulse. Normal muscle bulk and appearance for his age. Focused right elbow examination showed normal range of motion and no pain with flexion/extension. No locking or swelling. He did have laxity of his right elbow with valgus stress. DIFFERENTIAL DIAGNOSIS: 1. Valgus extension overload. 2. Osteochondritis dissecans. 3. Olecranon stress fracture. 4. Medial epicondyle avulsion fracture. 5. Medial apophysitis. 6. Medial epicondylitis. 7. Ulnar collateral ligament (UCL) sprain or tear. 8. Ulnar neuritis/subluxation. TESTS AND RESULTS: Initial MRI 18 months prior showed no UCL injury, but rather fluid at the flexor pronator mass consistent with medial epicondylitis. New MRI showed a partial right UCL tear at the proximal insertion. No full tear, fracture, or other connective tissue injury. Under ultrasound, laxity of the right UCL and pathology consistent with the partial UCL tear was seen, with no fracture, loose bodies, or epicondylitis. FINAL WORKING DIAGNOSIS: Partial UCL tear at the right elbow. TREATMENT AND OUTCOMES: We injected platelet rich plasma (PRP) under ultrasound to the pathologic site of the right UCL. The boy then proceeded with our 12-week PRP rehabilitation protocol tailored to throwing athletes. At 8 weeks post-injection, ultrasound showed interval healing with reduced laxity of the right UCL. At 16 weeks post-injection, ultrasound revealed virtually complete healing with no laxity of the right UCL. The boy eventually returned to throwing full pitching distance without pain, emphasizing the potential utility of PRP injection in pediatric/adolescent athletes with musculoskeletal injuries.