Level of evidence and type of surgery performed in included studies
| Study | Study design | Level of evidence | Subjects | Type of surgery |
|---|---|---|---|---|
| Surgical treatment only (athletes vs matched non-athletes) | ||||
| Mochida, et al32 | Retrospective cohort study | 4 | Elite athletes vs matched non-athletes | Percutaneous nucleotomy/discectomy |
| Surgical treatment only (athletes vs manual labourers) | ||||
| Matsunaga, et al33 | Retrospective cohort study | 4 | Club team or professional athletes vs manual labourers | Percutaneous discectomy |
| Surgical treatment only (athletes only) | ||||
| Sakou et al34 | Retrospective cohort study | 4 | Athletes in various sports participating in national meets | Percutaneous discectomy |
| Savage, et al37 | Retrospective cohort study | 4 | NFL athletes | LD |
| Watkins and Williams35 | Retrospective cohort study | 4 | Professional and Olympic athletes | Microdiscectomy |
| Watkins, et al36 | Retrospective cohort study | 4 | Professional athletes | Microdiscectomy |
| Yoshimoto, et al29 | Retrospective cohort study | 4 | Elite athletes | Microdiscectomy |
| Surgical vs conservative treatment (athletes only) | ||||
| Earhart, et al30 | Retrospective comparative study | 3b | MLB athletes | Microdiscectomy and/or laminotomy/foraminotomy |
| Hsu26 | Retrospective cohort study | 4 | NFL | LD |
| Hsu, et al27 | Retrospective cohort study | 4 | Elite athletes in NFL, NBA, NHL and MLB | LD |
| Schroeder, et al28 | Descriptive epidemiological study | 3b | NHL athletes | LD |
| Weistroffer and Hsu31 | Case series: Retrospective cohort study | 4 | NFL linemen | Open or tubular laminectomy |
| Surgical treatment vs control group (matched asymptomatic athletes without intervention) | ||||
| Anakwenze, et al25 | Retrospective case–control | 3b | NBA athletes | LD |
| Wang, et al14 | Retrospective cohort study | 4 | NCAA athletes | Microdiscectomy, percutaneous discectomy |
LD, lumbar discectomy; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey League; RTS, return to sport.