Anterior Band UCL Detail

fasciculus anterior ligamenti collateralis medialis cubiti

The anterior band of the ulnar collateral ligament (UCL) is the primary stabiliser against valgus stress at the elbow, running from the medial epicondyle to the sublime tubercle of the coronoid process. It is the primary ligament injured in overhead throwing athletes.

Region: Upper Arm

Biomechanics

Function & Actions

The primary restraint against valgus opening of the elbow, critical in the late cocking and early acceleration phases of throwing when valgus stress exceeds 60 Nm. The anterior band has a broad origin on the medial epicondyle and a narrow insertion at the sublime tubercle.

Clinical Relevance

Clinical Notes

UCL reconstruction (Tommy John surgery) is the most common elbow ligament procedure in baseball pitchers. The graft (typically palmaris longus or gracilis) is placed through bone tunnels at the medial epicondyle and sublime tubercle. The anterior band is assessed by the moving valgus stress test and ultrasound dynamic assessment.

Pathology

Common Injuries & Conditions

UCL Reconstruction (Tommy John Surgery)

Anterior band UCL reconstruction using palmaris longus or gracilis graft for chronic medial elbow instability in throwing athletes, requiring 12-18 months rehabilitation before return to competitive pitching.

UCL Tear in Overhead Throwing Athletes

Acute or insidious anterior band UCL disruption producing medial elbow pain during late cocking and acceleration phases, identified by MR arthrography and the moving valgus stress test.