Table 2.

Difference of CT-based and X-ray image projection angles automatically computed for varying approaches on instrumented cadavers compared with the gold standard, where fiducials are placed in the specimen

	CT reformats				X-ray projection images
	F-CE	F-AC	S-AC	AcAV	CE	AC
Trial 1 (left hip)
BGS	−0.5	0.4	0.6	2.2	−0.7	0.6
PCR	0.8	−0.8	1.5	3.7	2.4	−2.1
Postop	4.9	−1.0	−8.1	−0.3	−2.3	3.6
Trial 2 (left hip)
BGS	1.6	−1.9	0.2	1.2	1.8	−1.7
PCR	0.5	−1.0	0.6	0.9	0.8	−0.8
Postop	−4.9	0.7	−2.1	−0.2	−2.6	−1.3

“BGS” is computed intraoperatively using the system; “PCR” is the postoperative contour registration. “Postop” uses the acetabular lunate segmented directly from the postoperative CT scan. All measurements are in degrees