. 2016 Mar 23;158:981–988. doi: 10.1007/s00701-016-2777-5

Table 3.

Decrease in height and width of the dural sac in postoperative phase: intraoperative dimensions measured by orthopaedic surgeon compared to postoperative dimensions on prone MRI

	Intraoperative (n = 20)	Postoperative prone MRI (n = 20)
	Orthopaedic surgeon	Radiologist 1 (R.B.)	Radiologist 2 (M.G.)
Mean height in mm (±SD)	15.6 (±2.8)	12.8 (±2.8) −2.8 (±3.3)^a <0.001^b	13.7 (±3.0) −1.9 (±3.7)^a 0.032^b
Mean width in mm (±SD)	14.6 (±1.4)	12.5 (±3.4) −2.1 (±3.2)^a 0.008^b	12.1 (±2.8) −2.5 (±2.7)^a <0.001^b
Mean length in mm (±SD)	17.7 (±5.9)	22.2 (±7.0) 4.5 (±3.3)^a <0.001^b	22.2 (±7.1) 4.5 (±3.9)^a <0.001^b

Statistics: paired t-test

n number of patients, mm millimetres, SD standard deviation

^aMean change compared to intraoperative situation (mean of paired differences)

^b P value for comparison with intraoperative measurements