Ultrasound of distal brachialis tendon attachment: normal and abnormal findings.

OBJECTIVE: To demonstrate normal and abnormal findings of distal brachialis tendon attachment in cadavers, normal volunteers and patients by means of ultrasound.
METHODS: 3 cadaveric specimens, 30 normal volunteers and 125 patients were evaluated by means of ultrasound. Correlative MRI was obtained in volunteers.
RESULTS: In all cases, ultrasound demonstrated the distal brachialis tendon shaped by two distinct tendons belonging to the deep head and superficial head of the brachialis muscle. Correlative MRI demonstrated that the brachialis is composed of two distinct tendons in 83% of volunteers (25/30). In the patient group, four avulsions with bony detachment involving the deep head, one delayed onset muscular soreness and three tendinous detachments with no bony avulsion involving one or two tendons were identified. The four patients with bony avulsion were immediately referred to the orthopaedic surgeon for a pre-surgical evaluation. Patients without bony avulsion were not referred to the surgeon.
CONCLUSION: Detailed anatomy of the distal tendon is discernible in 100% of cases with ultrasound. There are two distinct tendons, and ultrasound can differentiate isolated lesions. In patients with distal brachialis tendon lesions, ultrasound may modify the clinical management of the patient. Advances in knowledge Detailed anatomy of the distal brachialis tendon is discernible with ultrasound and there are two distinct tendons.