A cross-sport comparison of performance-based outcomes of professional athletes following primary microfracture of the knee

Michael S. Schallmo, Sameer K. Singh, Kathryn A. Barth, Ryan D. Freshman, Harry T. Mai, Wellington K Hsu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


Background: The purpose of this study was to compare performance-based outcomes among professional athletes in four major North American sports following microfracture to treat symptomatic chondral defects of the knee. Methods: Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL) athletes who underwent primary unilateral microfracture of the knee were identified through a previously reported protocol based on public sources. Successful return-to-play was defined as returning for at least one professional regular season game after surgery. Regular season player statistics and sport-specific performance scores were compiled for each player. Each player served as his own control, with the season prior to surgery defined as baseline. Comparisons across sports were enabled by adjusting for expected season and career length differences between sports and by calculating percent changes in performance. Results: One hundred thirty one professional athletes who underwent microfracture were included. One hundred three athletes (78.6%) successfully returned to play. The ratio of games started-to-games played before surgery was found to be a significant positive independent predictor of returning (p = 0.002). Compared with their preoperative season, basketball and baseball players demonstrated significantly decreased performance one season after surgery (− 14.8%, p = 0.029 and − 12.9%, p = 0.002, respectively) that was recoverable to baseline by postoperative seasons 2–3 for baseball players but not for basketball players (− 9.7%, p = 0.024). Conclusion: Knee microfracture surgery is associated with a high rate of return to the professional level. However, the impact of this procedure on postoperative performance varied significantly depending on sport.

Original languageEnglish (US)
Pages (from-to)692-698
Number of pages7
Issue number4
StatePublished - Aug 1 2018


  • Chondral injury
  • Knee microfracture
  • Marrow stimulation
  • Professional sports
  • Return-to-play

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine


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