The ulnar collateral ligament (UCL) is a band of tissue located on the inner side of the elbow joint that connects the humerus to the ulna. It provides stability to the elbow during overhead throwing motions. A UCL injury refers to stretching, partial or complete tearing of the ulnar collateral ligament.

Common Symptoms

• Pain and tenderness on the inner side of the elbow
• Swelling around the elbow joint
• Stiffness and decreased range of motion
• A feeling of looseness or instability in the elbow
• Numbness or tingling in the ring and little fingers (in severe cases)

Cause & Anatomy

Causes of Ulnar Collateral Ligament Injuries:

• Overuse injury from repetitive overhead throwing motions (common in baseball pitchers)
• Acute trauma like a fall on an outstretched arm

The UCL complex consists of three bands:

• Anterior bundle (also called UCL or MUCL) – primary restraint to valgus stress
• Posterior bundle
• Transverse/oblique bundle

The anterior bundle has anterior and posterior components that provide reciprocal function during elbow flexion and extension.

Diagnosis

• Physical examination to assess instability, pain, swelling
• X-rays to check for bone injuries
• MRI to evaluate the ligament and surrounding soft tissues

Prevention

• Proper conditioning and throwing technique
• Avoiding overuse by adhering to pitch counts/limits
• Allowing adequate rest between throwing sessions

Treatment

Non-surgical:

• Rest, ice, medications, bracing, physical therapy (for partial tears)

Surgical:

• UCL reconstruction (e.g. Tommy John surgery) for complete tears, using tendon graft

Surgery

UCL Reconstruction Surgery “Tommy John Surgery”

• The damaged UCL is replaced with a tendon graft, commonly from the forearm, knee or hamstring. The graft is positioned to recreate the native anatomy and isometry of the UCL.

Rehabilitation After Surgery

• Immobilization with a hinged brace for several weeks
• Gradual range of motion exercises
• Strengthening and conditioning program over 9-12 months before returning to throwing

FAQ’s

Who is at risk for UCL injuries?
Overhead throwing athletes, especially baseball pitchers, are at highest risk due to the extreme valgus stress placed on the elbow during the throwing motion.