Ulnar Collateral Ligament Injury & Instability
In general, ligaments stabilize and reinforce connections between bones at a joint. They are composed of tough connective tissues that can withstand incredible stresses and force while maintaining the proper alignment and motion of joints. When ligaments are torn, joints can become unstable, weak, and dysfunctional.
The ligaments on the inside of the elbow, the Ulnar Collateral Ligament Complex, provide the stability throwing athletes need to deliver a fastball, launch a javelin, or spike a volleyball. Injury and instability of these ligaments is becoming increasingly common, not only in professional athletes like major league pitchers, but in young school-age athletes whose practice and competitive seasons have begun to run nearly year-round. In addition to being painful and disruptive, these injuries can be career-ending in overhead throwing athletes.
The ulnar collateral ligament complex, or UCL, is comprised of three component ligaments: the anterior oblique, posterior oblique, and transverse ligaments.
Anterior oblique: This ligament is the primary stabilizer and bears the brunt of the valgus, twisting force during elbow flexion and extension, such as during the late cocking and acceleration phases of overhead throwing.
Posterior oblique: A weaker, fan-shaped ligament that functions as a secondary stabilizer when the elbow in about 30 degrees of flexion.
Transverse ligament: This ligament traverses the notch between the olecranon and coronoid process of the ulna. It does not span the joint and so contributes little to joint stability.
There are two main types of UCL injuries, the slow deterioration and tearing of the ligament over a long period of overuse, or a new acute rupture or complete tear of the ligament.
Most injuries have a more gradual onset resulting from repetitive stressing of the ligament. Though the UCL already bears the brunt of the much of the force across the elbow in throwing or overhead swinging motions, other muscles also contribute to the stability of the joint. However poor mechanics, inflexibility, or simple fatigue can lead to muscle strain and weakness. As muscles give out, even more stress is placed on the UCL leading to microscopic tears in the ligament, which, over time, can cumulatively stretch out, or even add up to one big tear of the ligament.
An acute rupture of the UCL can occur even in the absence of prior micro-tearing when an excessive valgus force simply overwhelms the tensile strength of the ligament. This kind of injury is not uncommon in wrestlers whose elbows are often subjected to extreme torque. It may also result from a fall, often in conjunction with a dislocation of the elbow.
Pain along the inside of the elbow is the first and most common symptom of UCL tearing or instability. Throwing athletes often report experiencing the most significant pain during the acceleration phase of their throw. They may also notice diminishing speed or accuracy. Loose fragments of torn ligaments or cartilage may also cause mechanical symptoms of catching, popping, or grinding.
Someone experiencing an acute UCL rupture may feel or hear a pop. They may have swelling and some loss of motion in the elbow or even bruising.
Both chronic and acute UCL injuries can occasionally place stretch or pressure on the ulnar nerve at the elbow causing numbness in the small and ring fingers or even weakness of the hand. This is a more serious symptom that needs prompt attention from a physician.
Generally, initial treatment of UCL instability or injury is conservative and limited to rest (in a brace or splint for acute injuries), anti-inflammatory pain medication, and some icing. As initial symptoms improve, athletes may be able to transition into modified activities limiting reps and intensity. They may also need to seek the help of a therapist to make changes to their throwing mechanics and to improve their strength and stability. Without surgery, the instability resulting from a tear of the UCL may inhibit an athlete’s ability to participate in throwing sports. However, with simple conservative treatments most are able to recover to a point where the instability no longer interferes with activities of daily living, such as carrying a bag of groceries. Most can even return to exercising, lifting weights, batting, running, or other non-throwing sports without noticeable limits.
When conservative treatments fail, especially when throwing athletes struggle to regain full use of the elbow, several surgical options are available. When pain is the main symptom in the absence of instability, a surgeon may simply perform an elbow arthroscopy using a small camera to evaluate the elbow joint from the inside. This procedure allows for any tissue fragments, bone spurs, or frayed edges to be cleaned up and removed.
Damage to the UCL from an acute injury such as a fall may be repaired directly. In this procedure the surgeon will likely secure the ligament back to the bone with sutures anchored in holes drilled through the bone.
A ligament that is too weakened by long-term overuse may simply need to be replaced with a new “ligament.” An ulnar collateral ligament “reconstruction” involves replacing the ligament with a tendon graft taken from somewhere else in the body, often the leg or forearm (autograft) or instead replacing it with a tendon from a cadaver (allograft).
Following a simple arthroscopic debridement, patients can start gentle range of motion exercises right away and are often back to full strength and participation in sports within 1-3 months.
Recovery following a repair or reconstruction of the UCL begins with elbow immobilization in a bulky dressing and splint immediately following surgery. Patients can work on gentle finger and shoulder mobilization in this early stage. At about 10-14 days after surgery the bulky dressing and sutures are removed and early rehabilitation is started. Most patients will wear a hinged elbow brace that allows for some active motion of the elbow within defined parameters while protecting the repair. Athletes wanting to return to a throwing sport are unlikely to begin any actual throwing until 6 months after their surgery with full recovery taking up to 8-10 months. Still, most athletes do return to their pre-surgery performance levels following a repair or reconstructive surgery.
By Dale Belnap, PA-C