Table 2. Summary of 3DP used in spinal surgical guides.

Year	Author	Location	Material	Technique	Cost	Manufacture time	Patients/specimens	Total no. of pedicle screws	Accuracy–Experimental	Accuracy–Control
2007	Owen et al. (31)	Cervical	Acrylonitrile butadiene styrene	Fused deposition modelling	$30–$50	–	1	2	100%	–
2009	Lu et al. (32)	Lumbar	Acrylate resin	Stereolithography	$20	16 hours	12	58	100%	–
2009	Lu et al. (33)	Cervical	Acrylate resin	Stereolithography	$20	16 hours	9	19	100%	–
2011	Lu et al. (34)	Cervical	Acrylate resin	Stereolithography	$20	1 day	6	84	97.6%	–
2015	Chen et al. (35)	Lumbar	Polyamide	SLS	–	–	43	240	100%	98.4%
2016	Chen et al. (36)	Thoracic	Photo-sensitive resin	Stereolithography	–	–	3	50	100%	–
2016	Deng et al. (37)	Cervical	Photo-sensitive resin	Stereolithography	–	–	10	48	97.9%	–
2016	Huang et al. (38)	Cervical	–	Rapid prototyping	–	–	1	2	100%	–
2016	Liu et al. (39)	Thoracic	Photo-sensitive resin	Stereolithography	$290	1–2 days	10	152	93.8%	78.8% (freehand)
2016	Lu et al. (40)	Cervical	–	–	$20–$400	1–7 days	–	–	–	–
2016	Otsuki et al. (41)	Cervical umbar	Titanium	Selective laser-melting (SLM)	–	–	3	5	100%	–
2016	Takemoto et al. (42)	Thoracic	Titanium	SLM	$100	1 day	40	466	98.7%	–
2017	Guo et al. (30)	Cervical	Polylactic acid	Stereolithography	–	–	13	74	94.6%	70.27% (fluoroscopy)
2017	Sugawara et al. (43)	Cervical	Acrylate	Polyjet printing	$100	4–6 days	12	48	100%	–

SLS, selective laser sintering.