Distal partial ruptures of triceps brachii tendon
The triceps is a tripennate muscle with origins on the infraglenoid tubercle of the scapula (long head), the upper posterior humerus (lateral head), and lower posterior humerus (medial head). The distal insertion is primarily on the olecranon, with a lateral aponeurotic expansion that extends distally over the anconeus to the proximal forearm fascia. Rupture of the triceps tendon usually occurs at or near the insertion of the tendon onto the olecranon, as a result of an active contraction of the triceps in extension with a forced passive flexion. Rupture is often associated with pre-existing systemic conditions or drug treatments, including the local or systemic of steroids, anabolic steroid use, local steroid injection. Treatment depends on the extent of the rupture, level of activity and age of the patient. Good results of conservative treatment is often effective in these cases. X ray on lateral view may show small fleck of bone avulsed from the olecranon "flake sign".