Table 3 Characteristics of lesions of L5 or non-L5 spondylolysis

Total

349

217

132

 Bone union after conservative treatment

275

162

113

0.015^*

Main side stage

0.0025^*

 Pre-lysis

117

60

57

 − 2.98

0.0047

 Early

151

96

55

0.47

0.36

 Progressive

81

61

20

2.78

0.0083

Unilateral

128

79

49

1.00^*

Bilateral

221

138

83

Contralateral side stage

0.015^*

 None (= unilateral)

128

79

49

 − 0.10

0.40

 Pre-lysis

49

24

25

 − 2.04

0.050

 Early

76

42

34

 − 1.38

0.15

 Progressive

57

40

17

1.38

0.15

 Terminal

38

31

7

2.63

0.013

 Pedicle fracture

1

1

0

n/a

Mean conservative treatment duration (days)

110

110

109

0.11^**