Study	Reason for exclusion
Brooke 1991	Observational study
Brudny 1985	Case report
Cool 1989	No outcome of interest
Daviet 2002	No outcome of interest
Egan 1990	Descriptive study
Enstrom 1980	Descriptive study
Ferreri 1974	Descriptive study
Gracies 2000	No outcome of interest
Krempen 1977	Observational study
Moodie 1986	Observational study
Morin 1997	No outcome of interest
Patterson 1984	No data available
Peters 2003	Case report
Rajaram 1985	No outcome of interest
Roy 1989	Case report
Sodring 1980	Descriptive study
Spaulding 1999	No outcome of interest
Sullivan 1989	Descriptive study
Walker 1983	Descriptive study
Williams 1988	Observational study
Zorowitz 1995	Observational study
Zorowitz 1996	No outcome of interest
Zorowitz 2001	No outcome of interest