Ulnar Collateral Ligament reconstruction (Tommy John)


While there are a number of ligaments around the elbow that provide stability, the most commonly injured is the medial ulnar collateral ligament (UCL or Tommy John ligament). This ligament is on the inside (medial) part of the elbow that is closest to the body. Although injury to the medial ulnar collateral ligament (Tommy John ligament) is most commonly thought of in overhead throwing athletes (i.e., baseball, softball, or javelin throwers), it can also occur in gymnasts, wrestlers, football players, or other contact athletes.

These injuries can be the result of a sudden, acute injury, or they can occur following long periods of overuse. Injuries to the UCL can vary significantly in severity as the ligament can tear partially or completely, and it can tear in different locations (proximal, distal, or mid-substance). All of these factors must be taken into consideration when determining the optimal treatment strategies for UCL injuries.

In recent years, there have been significant increases in the rates of UCL injuries. Accordingly, in addition to studying the optimal treatment strategies of these injuries, much of the research performed by the Mayo Clinic Sports Medicine team is focused on injury prevention and identifying athletes at risk.  

  • Feeling or hearing a “pop” in the arm
  • Pain on the inside (medial) part of the elbow
  • Decreased elbow motion
  • Inability to throw a baseball, softball, or other object
  • Decreased throwing velocity, control, and/or stamina

Seek immediate care if any injury to your elbow causes signs or symptoms of a UCL injury. This is especially true if you feel a “pop” in the inside part of the elbow while throwing. It’s important to get a prompt and accurate diagnosis to determine the severity of the injury and get proper treatment. If you are unable to throw or have pain that is negatively affecting your throwing, you should be evaluated. This is particularly true if the pain doesn’t completely resolve after a few days of rest.

UCL injuries often happen during sports and fitness activities that can put stress on the inside part of the elbow:

  • Repetitive throwing or other overhead motions
  • Landing on the arm during a fall
  • Having a direct force or blow to the outside of the elbow that makes the elbow collapse inward

Risk factors

There are a number of factors that increase your risk of a medial ulnar collateral ligament injury:

  • Year-round throwing without allowing a period of down time for the arm
  • Throwing at very high velocities
  • High number of throws in a single day or back-to-back days
  • Improper throwing mechanics
  • Decreased shoulder range of motion or poor positioning of your shoulder blades
  • Participation in sports that require weight bearing on the arms (gymnastics)
  • Participation in contact sports where other athletes can fall into your elbow (football, wrestling, etc.)

Determining the optimal treatment for UCL injuries must be tailored to the individual patient. A number of factors are considered such as: hand dominance, sport, athletic career goals, injury severity, injury location, and timing of the athletic season. Nonoperative management with rest, physical therapy, and activity modification is considered for many patients. This is particularly true for athletes with partial tears of the ligament and those that are not overhead throwers. Physical therapy focuses on identifying and correcting any weakness or abnormal movement patterns in your entire “kinetic chain” including the legs, hips, torso, back, shoulder blades, shoulders, and elbows. For patients who have full thickness tears and need to return to high demand throwing type activities, surgery may be considered. Surgery typically entails either a repair (fixing your current ligament by sewing and anchoring it back down to the bone) or reconstruction (replacing your injured ligament) of the UCL.


Athletes who experience UCL injuries typically experience very high rates of return to athletics (95-100% for non-throwers and 85-95% for throwers).

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