Table 1. .

Study Design, Participant Characteristics, Exposures, and Outcomes for Studies (n = 4) Included in the Systematic Review Extended on Next Page

Authors (Year)	Cohort Study Design	Participant Characteristics	Exposure Definition: Treatment Type
			Surgical	Nonsurgical
Lohmander et al23 (2004)	Retrospective	Age range = 26–40 y, women only, Swedish, league soccer: identified through insurance company archive	Various reconstruction methods (62% autologous patellar tendon graft), n = 41 with radiographic data	No explanation of nonoperative treatment, n = 26 with radiographic data
Kessler et al41 (2008)	Retrospective	Age range = 12.5–54 y, males = 62%, females = 38%, participants matched age, sex, body mass index, Tegner score, follow-up	Bone–patellar tendon–bone reconstruction, procedures performed by various practitioners, radiographic data: n = 60	Standardized, nonoperative treatment program, carried out by various physiotherapists, radiographic data: n = 49
von Porat et al32 (2004)	Retrospective	Age range = 30–56 y, men only, Swedish league soccer players identified through insurance company archive	Various surgical methods (most common: patellar tendon graft)	No explanation of nonoperative treatment
Meuffels et al25 (2009)	Retrospective	Mean age = 37.7 y, males = 76%, females = 24%, Netherlands, participants matched by age, sex, Tegner score	Bone–patellar tendon–bone reconstruction, performed by 1 of 2 surgeons, radiographic data: n = 50	Rehabilitation program: edema reduction, range of motion, hamstrings and quadriceps strengthening exercises

Abbreviation: KL, Kellgren-Lawrence Scale.

^aMaximum possible score for modified instrument = 10.