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

Table 4.

Height measured on myelography compared to intraoperative and postoperative height

	Myelography (n = 20)	Intraoperative measurements by orthopaedic surgeon (n = 20)	Postoperative prone MRI (n = 20)	Postoperative supine MRI (n = 9)
Mean height in mm (±SD)	8.6 (±2.4)	15.6 (±2.8) 7.0 (±3.3)^a 0.000^b	R.B.: 12.8 (±2.8) 4.2 (±3.6)^a 0.000^b	R.B.: 15.7 (±2.8) 7.2 (±3.4)* 0.000^b
Mean height in mm (±SD)	8.6 (±2.4)	15.6 (±2.8) 7.0 (±3.3)^a 0.000^b	M.G.: 13.7 (±3.0) 5.1 (±4.3)^a 0.000^b	M.G.: 16.1 (±2.3) 7.6 (±2.7)* 0.000^b

Statistics: paired t-test

n number of patients, mm millimetres, SD standard deviation

^aMean difference compared to myelography (mean of paired differences)

^b P value for comparison with myelography