Isolated pronator teres muscle belly tear in a cricket batsman: A case report and review of the literature

Isolated traumatic rupture of the pronator teres (PT) muscle belly is an exceptionally rare sporting injury, with most flexor-pronator mass pathology involving the common flexor tendon origin or the medial collateral ligament. We describe the clinical and high-resolution musculoskeletal ultrasound findings of an isolated tear of the superficial head of the PT in a cricket batsman presenting with a persistent forearm mass. A 47-year-old male presented with a focal, palpable mass in the proximal volar forearm 2 months after experiencing sudden, sharp pain during a competitive cricket bat swing. High-resolution ultrasound demonstrated a localized hypoechoic structural defect and muscle fiber retraction confined entirely to the superficial (humeral) head of the PT. The deep ulnar head and the adjacent median nerve were structurally intact and unaffected. Color Doppler showed active internal hypervascularity consistent with subacute granulation tissue. The patient was managed conservatively with excellent clinical recovery. An isolated tear of the superficial head of the PT can clinically mimic a soft-tissue neoplasm when presenting as a chronic focal bulge. High-resolution ultrasound is an effective, dynamic modality to confirm the benign nature of the mass, map the specific muscular heads involved, and verify the integrity of the adjacent median nerve.