Ulnar collateral ligament reconstruction

The ulnar collateral ligament (UCL) can become stretched, frayed or torn through the repetitive stress of the throwing motion. The risk of injury to the UCL is believed to be extremely high, as the amount of stress through the structure approaches its ultimate tensile strength during a hard throw.[2]

This injury is associated with baseball, although it sometimes appears in other sports. Compared to athletes who play other sports, baseball players are at elevated risk of overuse injuries and injuries caused by early sports specialization among children and teenagers.[3]

While some sources say that an individual's style of throwing or the type of pitches that they throw are the most important determinant of their likelihood to sustain an injury, the results of a 2002 study suggest that the total number of pitches thrown is the greatest determinant.[4] A 2002 study examined the throwing volume, pitch type and throwing mechanics of 426 pitchers aged 9 to 14 for one year. Compared to pitchers who threw 200 or fewer pitches in a season, those who threw 201–400, 401–600, 601–800 and 800+ pitches faced an increased risk of 63%, 181%, 234% and 161% respectively. The types of pitches thrown showed a smaller effect; throwing a slider was associated with an 86% increased chance of elbow injury while throwing a curveball was associated with an increase in pain. There was only a weak correlation between throwing mechanics perceived as bad and injury-prone.

However, because there are many effective styles of pitching, incorrect throwing mechanics can be difficult to define and determine. One of the most common denominators among virtually all pitchers is "reaching back" with the throwing arm prior to release and follow-through. This repeated motion is believed to be a major contributing factor in UCL injuries, as it stretches the ligament in an unnatural manner and direction. Simply raising the pitching arm and bringing it forward with a complete follow-through produces the same levels of spin rate, velocity, movement and location while helping to protect the UCL from unnecessary injury.

Research into throwing injuries in young athletes has led to age-based recommendations for pitch limits.[5] A 2016 study explained 22% of the variation in those needing ulnar collateral ligament reconstruction, identifying handedness, standard deviation of release point, days lost to arm and shoulder injuries, previous ulnar collateral ligament reconstruction, number of hard pitches, ERA- and age as the known risk factors.[6]

In younger athletes whose epiphyseal plate (growth plate) is still open, the force on the inside of the elbow during throwing is more likely to cause the elbow to fail at this point than at the ulnar collateral ligament. This injury is often termed "Little League elbow" and can be serious but does not require reconstructing the UCL.

Increasingly often, pitchers require a second procedure after returning to pitching. During the periods from 2001 to 2012 and 2013 to 2015, 18 major-league pitchers underwent the procedure for a second time. As of April 2015, the average amount of time between procedures is 4.97 years.[7]

There is a risk of damage to the ulnar nerve.[8]

The rehabilitation process following surgery is typically divided into four separate phases.

1. Rehabilitation phase 1 (postoperative weeks zero to three) consists of prevention of stiffness, promotion of healing and simultaneous protection of the reconstructed graft with a hinged elbow brace.[14]
2. The goals of phase 2 (weeks four to eight) are to gain strength and gain full range of movement.[14]
3. During phase 3 (weeks nine to 13), the rehabilitation is focused on flexibility and neuromuscular control with a progression toward sports-related activities.[14]
4. The progression to a throwing program is made during phase 4 (weeks 14 to 26) for overhead athletes.[14]

Full competition throwing is usually permitted at seven to nine months, and pitchers are ready to return to the game at approximately 10 to 18 months.[14]

Over the past two decades, the number of UCLR surgeries has increased threefold, a rate that is expected to rise in upcoming years.[15] A study has shown that the rate of UCLR surgery for those aged 15 to 19 is the highest among all age ranges and is increasing by 9% each year.[16]

USA Baseball, Major League Baseball and Little League Baseball have initiated the Pitch Smart program designed to lower the risk of elbow injuries in adolescent pitchers.[17] The main risk factors for elbow injury from overhand throwing include number of pitches per game, innings pitched per season, months pitched per year and poor pitching biomechanics that may increase torque and force on the elbow.[18]

Tommy John, for whom the surgery is named, in 2008

At the time of John's operation, Jobe estimated the chance for success of the operation at 1 in 100.[19] By 2009, the odds of complete recovery had risen to 85–92%.[20]

Following his 1974 surgery, John missed the entire 1975 season rehabilitating his arm before returning for the 1976 season. Before his surgery, John had won 124 games. He won 164 games after surgery, retiring in 1989 at age 46.

For baseball players, full rehabilitation takes about 12–15 months for pitchers and about six months for position players. Players typically begin throwing about 16 weeks after surgery.[21] While 80% of players return to pitching at the same level as before the surgery, for those Major League Baseball pitchers who receive the surgery twice, 35% never pitch again in the major leagues.[7]

Jobe has stated that if he had invented the technique 10 years earlier, it might have been nicknamed Sandy Koufax surgery, after Dodgers hall of famer Sandy Koufax, who retired with "essentially the same thing as Tommy John."[22]