title: The effects of medial ulnar collateral ligament reconstruction on Major League pitching performance.
abstract: BACKGROUND
  Medial ulnar collateral ligament (MUCL) reconstruction is commonly performed on Major League Baseball (MLB) pitchers. Previous studies have reported that most pitchers return to presurgical statistical performance levels after MUCL reconstruction.
  
  
  METHODS
  Pitching performance data--specifically, earned run average (ERA), walks and hits per inning pitched (WHIP), winning percentage, and innings pitched--were acquired for 168 MLB pitchers who had undergone MUCL reconstruction. These data were averaged over the 3 years before surgery and the 3 years after surgery and also acquired from 178 age-matched, uninjured MLB pitchers.
  
  
  RESULTS
  Of the pitchers who had MUCL reconstruction surgery, 87% returned to MLB pitching. However, compared with presurgical data, pitching performance declined in terms of ERA (P = .001), WHIP (P = .011), and innings pitched (P = .026). Pitching performance also declined in the season before the surgery compared with previous years (ERA, P = .014; WHIP, P = .036; innings pitched, P < .001; winning percentage, P = .004). Compared with age-matched control pitchers, the MUCL reconstruction pitchers had significantly more major league experience at the same age (P < .001).
  
  
  CONCLUSIONS
  MUCL reconstruction allows most players to return to pitching at the major league level. However, after MUCL reconstruction, there is a statistically significant decline in pitching performance. There appears to be a statistically significant decline in pitching performance the year before reconstructive surgery, and this decline is also a risk factor for requiring surgery. In addition, there is an increased risk of MUCL reconstruction for pitchers who enter the major leagues at a younger age.
authors.affiliation: Department of Orthopaedic Surgery, Henry Ford Hospital, Detroit, MI, USA. Electronic address: robkeller23@gmail.com.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Keller
authors.affiliation: Department of Orthopaedic Surgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Steffes
authors.affiliation: Department of Orthopaedic Surgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: David
authors.initials: D
authors.lastname: Zhuo
authors.affiliation: Department of Orthopedics, Bone and Joint Center, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bey
authors.affiliation: Department of Orthopaedic Surgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Vasilios
authors.initials: V
authors.lastname: Moutzouros
mesh_terms: D000293:Adolescent; D000328:Adult; D001484:Baseball / Q000293:injuries* / Q000502:physiology; D017885:Collateral Ligaments / Q000293:injuries / Q000601:surgery*; D004551:Elbow Joint / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D019651:Plastic Surgery Procedures / Q000534:rehabilitation*; D012189:Retrospective Studies; D012307:Risk Factors; D016037:Single-Blind Method; D055815:Young Adult; D000092464:Elbow Injuries
keywords: Elbow; baseball; injury; pitcher; ulnar collateral ligament