Tommy John surgery
Tommy John surgery, known by doctors as  ulnar collateral ligament reconstruction (or UCL), is a surgical procedure in which a ligament in the medial elbow is replaced with a tendon from elsewhere in the body (often from the forearm, hamstring, knee, or foot of the patient).
The surgery is named after Tommy John, a pitcher for the Los Angeles Dodgers who was the first professional athlete to successfully undergo the operation in 1974. The procedure was performed by Dr. Frank Jobe.

# Process
There are several different techniques available for surgeons to employ, but the most common procedure involves harvesting an autograft tendon from the patient's own forearm (palmaris longus tendon) or hamstring (semitendinosus tendon). After the tendon is harvested, the flexorpronator mass of the forearm is incised and elevated. Some surgeons may use a submuscular or subcutaneous transposition of the ulnar nerve to try to reduce post-operative nerve symptoms or problems. Two holes are drilled into the ulna at the footprint of the UCL, and the tunnels are connected. An additional tunnel is drilled into the humerus. These bones help make what we colloquially refer to as the elbow joint. The autograft tendon is then woven in a figure-eight pattern through tunnels that have been drilled, reinforcing/reconstructing the native tissue of the UCL that was formerly injured by the patient.
There is a risk of damage to the ulnar nerve.

# Recovery
Chances of a complete recovery after surgery are estimated today at 85 to 90 percent. At the time of Tommy John's operation, Jobe put his chances at 1 in 100. After his surgery in 1974, John spent 18 months rehabilitating his arm, returned for the 1976 season, and went on to pitch in the major leagues until 1989 at age 46. Today, the procedure takes about an hour.  Full rehabilitation takes about a year for pitchers and about six months for position players.  Usually, pitchers who have the surgery can get their full range of motion back after about two months and can start doing weight exercises.  For the next four months, they can increase the weight that they use and start doing exercises that emphasize all parts of their arm. After six months, they can begin throwing .

# Risk of injury
The ulnar collateral ligament can become stretched, frayed or torn through the stress of the throwing motion.
The risk of injury to the throwing athlete's UCL of the elbow is thought to be extremely high as the amount of stress through this structure approaches its ultimate tensile strength during each and every hard throw.
In some cases, pitchers will seem to throw harder after the surgery than they did before the injury that caused the surgery to be necessary. However, many people -- including Dr. Frank Jobe, the doctor who invented the procedure -- believe this is generally due to two factors. The first is pitchers' increased attention to conditioning. The second is that in many cases it can take several years for the UCL to degrade. Over these years the pitcher's velocity will gradually decrease. As a result, the surgery simply allows the pitcher to throw at the velocity that they could before their UCL started to degrade.
Today, the injury and eventual surgery are becoming more common in children ranging from 10-18 years of age due to increased season length, the rise of travel teams (and tournament play), and the more frequent use of breaking pitches by young pitchers. Children have an additional risk factor because of the open growth plates in young bones. In younger athletes in whom the growth plate (the medial epicondylar physis) is still present the 'opening up' force at the inside of the elbow during throwing is more likely to sustain failure at this region (the growth plate) than at the Ulnar Collateral Ligament. This injury is often termed "Little League Elbow" and in these athletes therefore reconstruction of the Ulnar Collateral Ligament is not indicated.
While many authorities suggest that an individual's style of throwing or the type of pitches they throw are the most important aspects of their likelihood to sustain an injury, the greatest determinant seems to be the volume of throwing in total. In 2002 the results of a large study of young pitchers was published. In this work, 426 pitchers aged 9 to 14 were followed for a year and questioned as to their throwing volume, pitch type, and their throwing mechanics were examined. Using throwing 200 or less pitches in a season as a reference, those players who threw 201-400, 401-600, 601-800, and 800+ pitches were at an increased risk of 63%, 181%, 234%, and 161% respectively. Considering 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 curve ball was associated with an increase in shoulder pain. There was only a weak correlation between throwing mechanics perceived as bad and injury, although there is a large body of evidence that suggests that mistakes in throwing mechanics will increase the likelihood of injury it seems that the greater risk lies in the volume of throwing in total. Research into the area of throwing injuries in young athletes has led to the development of age-based recommenations for pitch limits to young athletes.

# List of baseball players receiving the surgery
All are pitchers unless otherwise noted.
- Brian Anderson
- Rick Ankiel (converted to position player after surgery)
- Andy Ashby
- Luis Ayala
- Brandon Backe
- Danys Baez (will be out for '08 season)
- Rocco Baldelli (position player)
- Rod Beck
- Erik Bedard
- Jeff Bennett
- Kris Benson
- Adam Bernero
- Dewon Brazelton
- A. J. Burnett
- Paul Byrd
- Jose Canseco (position player, though injured while pitching)
- Chris Capuano
- Chris Carpenter (currently rehabbing)
- Todd Coffey
- Manny Delcarmen
- Ryan Dempster
- Chris Denorfia (position player, currently rehabbing)
- Jorge DePaula
- Brendan Donnelly (currently rehabbing)
- Octavio Dotel
- Justin Verlander
- Adam Eaton
- Willie Eyre (currently rehabbing)
- Jesse Foppert
- Chad Fox (twice)
- Frank Francisco
- Eric Gagne
- Rusty Greer (position player)
- Luis Gonzalez (position player)
- Mike Gonzalez (current pitcher, not the former catcher; currently rehabbing)
- Mike Hampton (currently rehabbing)
- Pat Hentgen
- Runelvys Hernandez
- Shawn Hill
- Philip Humber
- Cesar Izturis (position player)
- Jason Isringhausen
- Tommy John
- Kelly Johnson (position player)
- Steve Karsay
- Jimmy Key
- Hong-Chih Kuo
- Jon Lieber
- Francisco Liriano (currently rehabbing)
- Matt Mantei
- Scott Mathieson
- Joe Mays
- Seth McClung
- Dustin McGowan
- Matt Morris
- Xavier Nady (position player)
- Russ Ortiz
- Juan Padilla
- Carl Pavano (currently rehabbing)
- Chris Ray
- Britt Reames
- Arthur Rhodes (currently rehabbing)
- Matt Riley (three times)
- Ricardo Rincon (currently rehabbing)
- Mariano Rivera
- Fernando Rodney
- Kenny Rogers
- Francisco Rosario
- B. J. Ryan (currently rehabbing)
- Anibal Sanchez
- Humberto Sanchez (currently rehabbing)
- Scott Schoeneweis
- Jae Weong Seo
- John Smoltz
- Rafael Soriano
- Tyler Walker
- David Wells
- Scott Williamson
- Vance Wilson (position player, currently rehabbing)
- Mark Wohlers
- Randy Wolf
- Kerry Wood
- Jaret Wright
- Tyler Yates
- Matt Young
- Victor Zambrano (twice)
- Jeff Zimmerman (twice)
- Donnie Baker (had a full ride scholarship to the University of Phoenix)

# List of football players receiving the surgery
- Jake Delhomme
- Craig Erickson
- Rob Johnson