Ligament Injuries around the Elbow

Three ligaments surround the elbow joint and act to provide stability to the joint. These include the medial (MCL or UCL) and lateral collateral (LUCL) ligaments, which originate on the inside and outside of the humerus before attaching to the ulna, and the annular ligament that connects the radius to the ulna. These ligaments act in continuity with the bones of the elbow and the muscles that cross the joint to provide stability during functional activities. These ligaments may be at risk for injury from an acute trauma (such as a fall down stairs), or from long standing stress on the ligament (such as from repetitive overhead throwing motion). When ligament injuries occur, they can result in congruency of the joint (malposition of the joint), which often causes pain, a sense of instability with activity, and can lead to the development of arthritis.

What is the LUCL and how is it injured?

The LUCL is a structure on the outside of the elbow that provides stability to the radial head, as well as the portion of the elbow that flexes and extends (ulnohumeral articulation). This structure is most commonly injured during traumatic events in which the elbow joint is dislocated.

What is an elbow dislocation and how is it treated?

An elbow dislocation refers to the disruption of the connection between the ulna and humerus. This requires a traumatic event in which the humerus is commonly twisted around a stationary forearm, such as during a fall onto an outstretched arm. During a dislocation event, the LUCL and other soft tissue structures that support the elbow are torn, allowing the bones to move out of alignment. Although these injuries seem severe, if there is not an associated fracture, most can be treated without the need for surgery. Treatment is initiated immediately with a reduction to put the bones back into the correct alignment. Although the soft tissue structures are torn in a dislocation, the bones of the elbow allow for immediate stability of the elbow with range of motion. In some patients, there can be residual instability of the elbow if there is severe soft tissue disruption or an associated fracture of the bones of the elbow. For these patients, surgery may be necessary to restore joint stability by fixing any fractures and reattaching the LUCL on the humerus.

What is the MCL and how is it injured?

The MCL is a structure on the inside of the elbow that, like the LUCL, originates on the humerus and attaches to the ulna. This structure provides stability to the ulnohumeral articulation and prevents excess stretch on the joint during throwing motions. The MCL can be injured during both acute traumatic events, such as dislocation, or with chronic stress conditions such as repetitive throwing.

How do MCL injuries present in throwing athletes?

Throwing athletes with an MCL injury may experience pain along the inside of the elbow with throwing. Typically, this pain occurs during the acceleration phase of the throwing motion (when the athlete brings the ball forward to throw after cocking). The pain is usually worse with harder throws. Some patients may also report an inability to completely straighten the elbow, and other patients may even complain of numbness and tingling in their small and ring finger while throwing. Commonly, the athlete will report that their velocity of throws diminishes and control becomes more difficult.

How are MCL injuries treated and what is the Tommy John surgery?

Initially, MCL injuries are treated without surgery. The patient’s activity is restricted to no throwing for a period of time. Sometimes, physical therapy and anti-inflammatory medications are used to help strengthen the muscles of the upper extremity and diminish swelling and inflammation. Patients with symptoms that persist may be candidates for a surgery commonly known as Tommy John surgery. This surgery is named after the first patient who underwent it, Tommy John, who was a major league pitcher that developed MCL insufficiency in 1974. At that time, MCL deficiency was considered a career-ending injury for most pitchers. However, after undergoing this initial MCL reconstruction by Dr. Frank Jobe, Tommy John pitched for 13 more seasons and won 164 games.

The Tommy John surgery reconstructs the MCL ligament with a tendon that is either harvested from the patient’s own forearm or is obtained from a donor. After surgery, the patient is placed into a hinged elbow brace and works on elbow range of motion for the first 6 weeks after surgery. Following this, the arm is started on a light strengthening program, but no throwing is allowed until 3-4 months from surgery. Throwing is slowly progressed through a throwing program for around another 5 months. Most patients do not return to competitive throwing until around 10-12 months from surgery. The reported rate of excellent outcomes following Tommy John surgery is around 83% in the literature.