A sprain is a joint injury that causes a stretch or tear in a ligament. A ligament is a strong connective band of tissue connecting one bone to another. An ulnar collateral ligament sprain of the thumb is a pianful injury that may cause looseness of the thumb joint at the base of the thumb where is attaches to the hand.

Sprains are classified as grade I, II, or III depending on the severity of the sprain

Grade I - pain with minimal damage to the ligament

Grade II - more ligament damage and mild looseness of the joint

Grade III - complete tearing of the ligament, and the joint is very loose or unstable

HOW DOES IT OCCUR?

A sprain of the ulnar collateral ligament in the thumb is a common injury in skiing. It may occur when you fall onto your outstretched thumb, bending it back toward your arm. This stretches and injures the ulnar collateral ligament. It may also be caused by catching your thumb on your ski pole strap. It may occur in other activities when you fall onto your outstretched thumb, or when your thumb gets hooked onto another player's jersey or face mask.

WHAT ARE THE SYMPTOMS?

You usually have pain, swelling, and tenderness at the inner part of the base of your thumb where it attaches to your hand. It may be difficult to hold an object in your hand and apply force with your thumb. Moving your thumb causes pain.

HOW IS IT DIAGNOSED?

Your doctor will review your symptoms, examine your thumb, and check to see if your thumb joint is loose. Your doctor may order an x-ray of your thumb to see if it is broken.