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What is an UCL Injury

The Ulnar Collateral Ligament or UCL is the ligament on the inside or medial aspect of the elbow that provides stability against forces that stress that part of the elbow. These forces are those commonly associated with throwing. It is made up of three components; the anterior band, posterior band, and transverse band. The anterior band is the most important and is the main stabilizer. This ligament is most commonly injured with throwing a baseball or javelin and with elbow dislocations.

Diagram of Ulnar Collateral Ligament

Ulnar Collateral Ligament

Signs and Symptoms of UCL Injury

Injury to the UCL may occur acutely with a single event or gradually over time. Acute injuries are usually associated with a painful pop and pain on the inner (medial) part of the elbow. Typically, one cannot throw anymore after this occurs. There is usually swelling in this area. There may be some numbness or tingling down into the small and ring fingers for a few seconds. Chronic injuries are more common and most often occur in baseball pitchers. The stress placed on the UCL with pitching exceeds the amount of force needed to tear the ligament. The ligament does not tear with each pitch due to the bony anatomy of the elbow, surrounding muscles, and mechanics of pitching. Over time, overuse, minor injuries, and bad pitching mechanics can lead to stretching out of the ligament and eventual failure. When this occurs, one cannot continue to pitch without pain and there is a loss of velocity and control. This may lead to Tommy John Surgery or UCL Reconstruction.

Dr. Khalfayan’s Tip!

If you feel pain on the inside (medial) part of the elbow, the arm feels tired, or you feel a pop while pitching, you should stop throwing and see a sports medicine specialist. Continuing to play may cause further damage to the elbow.

Evaluation and Diagnosis

If there is an acute injury to the UCL or a chronic one that affects one’s ability to throw, it should be evaluated by a sports medicine specialist familiar with throwing injuries. Many of these injuries are not diagnosed accurately or there may be a delay in making the correct diagnosis and treating the injury appropriately if a specialist is not seen.There is usually tenderness over the UCL on the inner part of the elbow. When the UCL is stressed on exam there is pain. X-rays, which may include stress views, and an MRI with an arthrogram (dye injection into the joint) are recommended to evaluate this injury adequately. Although X-rays and MRI are important, the symptoms and exam are more important in guiding treatment.

Xray of Normal UCL (white arrow, ligament is black)

Normal UCL (white arrow, ligament is black)

UCL Tear (white arrow at tear with leakage of dye)

UCL Tear (white arrow at tear with leakage of dye)

Treatment

A grade 1 sprain is when the ligament is stretched, but not torn. A grade 2 sprain is a partial tear of the ligament and there are varying degrees of grade 2 sprains. In general, grade 1 and 2 sprains are treated with a period of no throwing followed by a rehabilitation program. This may take 8- 12 weeks or more. Grade 3 sprains are complete or full thickness tears. These are best treated with reconstruction in baseball players and javelin throwers. There may be a role for repair of the ligament in some younger pitchers (early teens) or female athletes if the ligament tears off the bone. There are studies that have shown good results with direct repair of acute tears in these patients.

UCL Reconstruction or Tommy John Surgery is the norm and is performed by using a tendon graft to replace the UCL (see pictures of procedure below). The graft is placed through tunnels drilled the Ulna (bottom bone) and in the Humerus (top bone) of the elbow. A graft is a tendon used to replace the torn ligament. The most common graft is the Palmaris tendon, which is obtained from the forearm through a small incision in the wrist. The use of this tendon does not lead to any problems with the arm. Not everyone has a Palmaris tendon. Other graft options include use of a hamstring, toe extensor, or donor tendon (allograft). After the graft is passed into the tunnels and fixed, it is repaired directly to the old UCL to strengthen it. The surgery is done through a 3-4 inch incision on the inner part of the elbow. The surgery is an outpatient procedure allowing patients to go home the same day and a long arm splint is used to protect the repair for the first week. A brace is applied after the first week and worn until 6 weeks after surgery to protect the reconstruction.

Elbow rehabilitation is started 1 week after Tommy John surgery and continues until the player is able to pitch approximately 10-12 months after surgery (see UCL reconstruction rehabilitation protocol). The initial phase is aimed at decreasing swelling and restoring range of motion. A throwing program is started at 4 months after surgery if rehabilitation goals are met. Flat ground bullpens are started at 8-9 months and mound pitching is allowed at 9-10 months after surgery.

Dr. Khalfayan’s Tip!

It is not uncommon to have ups and downs during the throwing program. It is important to treat pain or soreness when it develops and adjust the throwing program as needed when this occurs. If it does not improve, you should inform your physician.

Visual of UCL Reconstruction: Incision

Incision for UCL Reconstruction

Forceps at the humeral attachment of the torn UCL (white tissue)

Forceps at the humeral attachment of the torn UCL (white tissue)

UCL is spread open allowing view of the joint

UCL is spread open allowing view of the joint

With gentle stress, the joint opens up due to the UCL tear

With gentle stress, the joint opens up due to the UCL tear

Palmaris Tendon -  UCL Reconstruction

Palmaris Tendon

Tunnels drilled in Ulna - UCL Reconstruction

Tunnels drilled in Ulna

UCL Reconstruction - Close up of completed tunnels in Ulna

Close up of completed tunnels in Ulna

Tunnel drilled in the medial epicondyle of the humerus

Tunnel drilled in the medial epicondyle of the humerus

Tommy John Surgery - UCL Graft in place

UCL Graft in place