Table 1.

Details of soccer players and baseball players with symptomatic spondylolysis

	Soccer players	Baseball players	p value
Number	33	49
Age (years)	15.4 ± 1.4	15.4 ± 1.6	n.s.
Interval from onset of low back pain to MRI (weeks)	3.5 ± 2.4	4.3 ± 4.1	n.s.
Number (%) of players with multiple HSL on STIR-MRI, n (%)	21 (63.6%)	10 (20.4%)	< 0.001
Number (%) of players with HSL at multiple lumbar levels on STIR-MRI, n (%)	7 (21.2%)	2 (4.1%)	0.03
Number (%) of players with bilateral HSL on STIR-MRI, n (%)	20 (60.6%)	9 (18.4%)	< 0.001

Data are expressed as mean ± SD unless otherwise indicated

HSL high signal lesion, STIR short tau inversion recovery, MRI magnetic resonance imaging, n.s. not significant