Techniques and accuracy of thoracolumbar pedicle screw placement

Table 1 Gertzbein classification[5]

Grade	Breach distance
0	0 mm (no breach)
1	< 2 mm
2	2-4 mm
3	> 4 mm

Table 2 Heary classification[22]

Grade	Breach
1	None
2	Lateral, but screw tip is within VB
3	Anterior or lateral breach of screw tip
4	Medial or inferior breach
5	Breach that requires immediate revision (due to proximity to sensitive structures)

Table 3 Summary of studies that have evaluated free-hand pedicle screw placement

	Most common pathology	Screw location	Number of patients	Number of screws	Accuracy (%)	Revision rate (%)
Gertzbein et al[5], 1990	Trauma	T8-S1	40	167	71.9	N/A
Liljenqvist et al[9], 1997	Scoliosis	T4-T12	32	120	75.0	N/A
Kim et al[23], 2004	Scoliosis	T1-T12	Unclear	577	93.8	0
Karapinar et al[31], 2007	Trauma	T10-L3	98	640	94.2	0
Schizas et al[32], 2007	Trauma	T1-T6	13	60	88.3	0
Kotil et al[33], 200	Trauma	T1-L5	Unclear	368	93.5	1.5
Modi et al[26], 2009	Scoliosis	T1-T12	43	854	93.0	N/A
Parker et al[27], 2011	Degenerative/Deformity	T1-S1	964	6816	98.3	0.8

N/A: Not applicable.

Table 4 Summary of studies evaluating fluoroscopy-aided pedicle screw placement

	Most common pathology	Screw location	Number of patients	Number of screws	Accuracy (%)	Revision rate (%)
Halm et al[44], 2000	Scoliosis	T10-L4	12	104	81.7	8.3
Belmont et al[7], 2001	Scoliosis	T1-T12	40	279	57.0	5.0
Carbone et al[45], 2003	Trauma	T1-T12	22	126	86.5	N/A
Kuntz et al[46], 2004	Trauma	T1-T12	28	199	27.6	N/A
Vougioukas et al[47], 2005	Degenerative	T1-T12	41	328	78.0	0.0
Amato et al[48], 2010	Degenerative	L1-S1	102	424	92.2	8.8

N/A: Not applicable.

Table 5 Summary of studies evaluating navigation-aided pedicle screw placement

	Most common pathology	Screw location	Number of patients	Number of screws	Accuracy (%)	Revision rate (%)
Idler et al[53], 1996	Postlaminectomy instability and spinal stenosis	L1-S1	30	139	95.7	N/A
Youkilis et al[14], 2000	Assorted	T1-T12	52	224	91.5	N/A
Bledsoe et al[58], 2009	Cervical deformity	T1-T3	34	150	93.3	0
Nottmeier et al[59], 2009	Unclear	T1-S1	184	951	92.5	N/A
Oertel et al[60], 2011	Degenerative Disease	T8-S1	50	278	96.8	0
Scheufler et al[55], 2011	Idiopathic and Degenerative Deformity	T2-S1	46	Ta-243	T-96.5	4.3
				LSb-542	LS-94.4
Dinesh et al[54], 2012	Metastasis	T1-T12	43	261	97.3	1.5 (intraop)
						1.2 (postop)
Lee et al[61], 2013	Degenerative Spondylolisthesis	T1-S1	178	932	96.8	1.4
Ling et al[62], 2013	Degenerative Disease	T5-S1	92	467	95.3	1.3 (intraop)

T: Thoracic spine; LS: Lumbosacral spine; N/A: Not applicable.

Table 6 Studies comparing navigation methods to either free-hand or fluoroscopic methods

	Most common pathology	Screw location	Method	Patients(n)	Screws(n)	Revisionrate (%)	Accuracy(%)	Method	Patients(n)	Screws(n)	Revisionrate (%)	Accuracy(%)	Studydesign
Amiot et al[34], 2000	Degenerative disease	T2-S1	CT-navigation	50	294	0	95	Fluoroscopy	100	544	2	85.0	R, P
Laine et al[63], 2000	Spinal stenosis	T8-S1	CT-navigation	41	219	4 (intraop)	95.4	Freehand	50	277	0 (intraop)	86.8	P
Rajasekaran et al[56], 2006	Deformity	T1-T12	Fluoroscopy-navigation	17	242	N/A	98	Fluoroscopy	16	236	N/A	77.0	P
Merloz et al[35], 2007	Trauma and degenerative disease	T8-L5	Fluoroscopy-navigation	26	140	N/A	95	Fluoroscopy	26	138	N/A	87.0	R
Tormenti et al[64], 2010	Deformity	T1-S1	CT- navigation	12	164	0	98.8	Fluoroscopy	14	211	7.1	94.8	R
Shin et al[65], 2013	Degenerative disease	T9-S1	O-arm navigation	20	124	5 (intraop)	91.9	Fluoroscopy	20	138	5 (postop)	87.7	P
Waschke et al[66], 2013	Trauma and degenerative disease	T1-S1	CT-navigation	505	2422	1.2	L-96.4	Fluoro- scopy	501	2002	4.4	L-93.9	R
							T-95.5					T-79.0

R: Retrospective; P: Prospective; N/A: Not applicable.