Table 4 General functional assessment

Oswestry disability index

 Preoperative

  Mean

34.13 ± 4.88

  Median

34.0

  Min–Max

27.0–42.0

 Postoperative

  Mean

11.47 ± 3.36

  Median

10.0

  Min–Max

8.0–21.0

  p

 < 0.001*

 Functional improvement range

   < 50%

2

   ≥ 50%

28

 Functional improvement (%)

  Mean ± SD

65.61 ± 11.01

  Median

69.0

  Min–Max

43.20–78.60