UCL Tears

The UCL connects the humerus (upper arm bone) to the ulna (one of the forearm bones) on the inner side of the elbow. It provides stability when the arm is bent and rotated during throwing or lifting. A UCL tear occurs when this ligament is overstressed or subjected to excessive force, causing ligament fibers to fray, stretch, or detach completely from the bone. Depending on the severity, the injury can range from a mild sprain to a complete rupture.

When the UCL is compromised, the elbow may feel weak or unstable, particularly when performing motions that require strong forearm rotation or resistance. Over time, the repeated stress that causes these injuries can also lead to inflammation, microtears, and progressive degeneration of the ligament.

Symptoms vary based on the severity of the injury. In athletes, especially pitchers, a UCL tear often begins as a dull ache on the inside of the elbow that worsens over time with continued throwing. In more acute injuries, such as a sudden tear, an athlete may feel a sharp pop followed by immediate pain.

Common symptoms include:

• Pain or tenderness along the inner side of the elbow
• Weak or clumsy grip
• A popping or tearing sensation during throwing or lifting
• Reduced elbow and arm function
• Reduced throwing velocity or accuracy
• Elbow stiffness or swelling
• A feeling of looseness or instability in the joint
• Numbness or tingling in the ring and little fingers (due to irritation of the nearby ulnar nerve)
• Difficulty performing overhead or forceful arm motions

Athletes may also notice that their performance declines before significant pain develops. A gradual decrease in throwing speed, loss of control, or fatigue in the forearm can be early signs that the ligament is weakening.

The most common cause of a UCL tear is repetitive stress on the elbow from throwing or overhead activities. Each time an athlete throws, the elbow endures tremendous force, often several times the body’s weight, which stretches and stresses the UCL. Over months or years, this repetitive load can cause microtears that eventually progress to a full rupture.

Specific causes include:

• Overuse from repetitive throwing or overhead movements
• Poor throwing mechanics that increase stress on the elbow
• Inadequate rest between practices or games
• Previous elbow injuries or inflammation
• Sudden traumatic events such as a fall onto an outstretched arm

While most UCL tears are seen in athletes, especially baseball players, they can also occur in non-athletes during high-impact injuries such as car accidents or falls. Occupational activities involving repetitive arm strain can also place individuals at risk.

Several factors increase the likelihood of developing a UCL tear:

• Repetitive overhead sports: Baseball pitchers, javelin throwers, tennis players, and volleyball athletes are at greatest risk.
• Improper throwing technique: Poor form places excessive stress on the ligament with every throw.
• High throwing volume: Throwing too frequently without adequate rest reduces the ligament’s ability to recover.
• Previous elbow injuries: Prior sprains or inflammation can weaken the ligament over time.
• Adolescent overuse: Young athletes who specialize in a single sport too early or play on multiple teams year-round face a higher risk of overuse injuries.

Diagnosis typically begins with a thorough history and physical examination. Dr. Kevin Collon, is an orthopedic surgeon and fellowship-trained in sports medicine expert at Keck Medicine of USC in Los Angeles, CA He will evaluate each patient carefully to determine the exact cause of their elbow pain. During the exam, he will assess joint stability, range of motion, and any tenderness along the inner elbow. Specific stress tests may be used to reproduce symptoms safely and identify laxity or instability.

Imaging studies such as X-rays, MRI, or ultrasound help confirm the diagnosis. X-rays can detect bone abnormalities or calcifications, while MRI scans provide detailed images of the ligament and surrounding soft tissues. In certain cases, a contrast-enhanced MRI (MR arthrogram) may be used to visualize even small tears.