UCL Injuries of the Elbow

What is the UCL?

The UCL (Ulnar Collateral Ligament) is a ligament on the inside part of the elbow. There are three bones that make up the elbow joint: Humerus, Ulna and Radius. The elbow joint is unique because it can bend and straighten as well as rotate and twist. There are two ligaments in the elbow that aid in preventing the elbow from dislocation-the RCL and the UCL. The UCL helps to connect the upper arm bone (Humerus) to one of the forearm bones (Ulna). The UCL stabilizes the elbow during the throwing motion, so it must be able to withstand a great amount of stress. There are also several nerves that run through the elbow and supply sensation to the forearm and fingers.

Elbow Diagram

How do UCL injuries occur?

UCL injuries are very common for throwing athletes and those that use their upper extremity frequently. They can result from an acute injury (sudden onset) or from a chronic injury (over time). An acute injury can occur if too much stress is put on the elbow in one single incident which can cause the ligament to tear. An audible ‘pop’ typically can be heard or felt with this type of injury and intense pain may accompany this.

A chronic injury typically occurs from repeated stress on the ligament from throwing or swinging the arm over time. This causes the ligament to be stretched, frayed or torn. If the ligament is stretched, the repetitive motion of throwing can cause small micro tears in the ligament which can result in rupture of the ligament.  Chronic injuries are more common than acute injuries for this ligament.

If there is an injury to the UCL it is often classified as a sprain. There are three grades of sprain: grade 1, 2 and 3. A grade 1 sprain means that the ligament is stretched but no tear is felt. A grade 2 sprain indicates the ligament is stretched and a partial tear could be present. A grade 3 sprain indicates there is a complete tear of the ligament.

What are the symptoms?

The most common symptom of a UCL injury is pain on the inside (medial) part of the elbow, especially during the acceleration phase of throwing. Swelling can also be present. If an acute injury occurred, swelling and bruising may also be noticed. A sensation of popping, grinding or clicking can sometimes be felt when throwing.

How are UCL injuries diagnosed?

If you notice any of the symptoms mentioned above, seeking an evaluation by a physician is the next step in diagnosing the injury. The physician will most likely do x-ray’s to rule out any type of fracture, stress reaction or loose fragments in the joint. During the physical exam portion, the physician will do several special tests to evaluate for a UCL injury. The most common test is called the Valgus stress test. A force is placed on the outside of the elbow which “opens up” the inside part of the elbow. If the UCL is working properly, it should stop the joint from opening up. If laxity (looseness) is felt during this test, it is indicative of a UCL sprain or tear. If laxity or pain are felt, this is indicative of a UCL sprain or tear. There are other special tests that can be performed, but the Valgus stress test is the most common.

If there is pain along the inside of the elbow and the Valgus stress test is positive, the physician will typically order an MR arthrogram. This is an MRI but dye is added through an injection into the elbow joint. The dye helps to make the test more accurate in that it goes into the space where a tear could be to make the tear easier to detect. If there is a tear present, surgery may be the best option to repair the tear.

How are UCL injuries treated?

UCL sprains can be treated conservatively or surgically. Conservative treatment includes rest, anti-inflammatories, physical therapy and bracing. Initially, rest and anti-inflammatories can be used to help reduce the pain and swelling. If the injury is acute, a sling may also be useful to aid in resting the elbow. Physical Therapy is a great resource for UCL injuries because it helps strengthen the muscles surrounding the elbow. This makes the elbow stronger and in turn helps to decrease the chance for further injury. A Physical Therapist can also evaluate the throwing mechanics to see if any changes need to be made in order to reduce the amount of stress on the elbow. Bracing can also be considered for support of the elbow or to reduce the amount of motion the elbow can have.

If there is a complete tear of the ligament or if pain and dysfunction persists despite conservative treatment, surgical intervention may be considered. This would include repairing the tear or reconstructing the tear. Many people are familiar with the name of this surgery which is called Tommy John’s surgery. The name is coined from the first person to ever have this type of surgery. This repair is performed when the ligament has completely torn off the bone. This is done by making an incision on the inside part of the elbow and reattaching the ligament to the bone. Sutures are used to keep the ligament in place when reattached to the bone. A reconstruction is performed when the ligament is unable to be reattached to the bone. A ligament in your wrist, called the Palmaris Longus, is often used to replace the UCL ligament if a reconstruction is performed.

What is the recovery after surgery?

Most patients are typically put in an elbow brace that limits range of motion after surgery. Each physician has different parameters for working on range of motion after surgery, but Physical Therapy will be required. The focus of Physical Therapy will be to get the proper range of motion back after surgery, although some patients may notice they have less range of motion than before. After this is achieved, the main focus will be strengthening the muscles surrounding the elbow and getting the person back to functional activity.

What’s the take away message?

Injuries to the UCL of the elbow are common, especially among throwing athletes and those who have to use their upper extremities for their sporting activity. If you notice pain along the inside of your elbow, you should seek treatment from an Athletic Trainer, Physician Assistant, Primary Care Physician or Orthopedic Surgeon. These healthcare providers all can evaluate the injury and formulate a treatment plan to help you get back to your sport.

https://orthoinfo.aaos.org/en/diseases–conditions/elbow-injuries-in-the-throwing-athlete

http://www.houstonmethodist.org/orthopedics/where-does-it-hurt/elbow/ulnar-collateral-ligament-injuries/