Table V.

Radiological assessment of robotic assisted total hip arthroplasty versus manual total hip arthroplasty for component position and accuracy of alignment according to Lewinnek’s and Callanan’s criteria.

Radiological assessment	rTHA	mTHA	OR/DIff (95% CI)	p-value
Mean horizontal centre of rotation, mm (SD)	0.2 (1.3)	-2.2 (4.5)	Diff: 2.4 (1.3 to 3.3)	< 0.001*
Mean vertical centre of rotation, mm (SD)	0.3 (0.9)	-0.1 (2.0)	Diff: 0.4 (-0.1 to 0.9)	0.132*
Mean combined offset, mm (SD)	0.5 (2.9)	1.0 (3.8)	Diff: 0.5 (-0.7 to 1.7)	0.419*
Mean acetabular offset, mm (SD)	0.2 (1.1)	-2.1 (4.4)	Diff: 2.3 (1.3 to 3.3)	< 0.001*
Mean femoral offset, mm (SD)	0.3 (1.6)	3.1 (4.0)	Diff: 2.8 (1.6 to 4.0)	< 0.001*
Mean leg length, mm (SD)	2.3 (3.0)	5.9 (6.0)	Diff: 3.6 (2.0 to 5.2)	< 0.001*
Component inclination, n (% of group)
Lewinnek’s safe zone	38 (95.0)	65 (81.3)	OR: 4.3 (1.0 to 20.2)	0.052†
Callanan’s safe zone	37 (92.5)	62 (77.5)	OR: 3.6 (1.0 to 13.0)	0.072†
Component anteversion, n (% of group)
Lewinnek’s safe zone	39 (97.5)	67 (83.8)	OR: 7.6 (1.0 to 60.1)	0.033†
Callanan’s safe zone	39 (97.5)	65 (81.3)	OR: 9.0 (1.1 to 70.8)	0.020†
Overall component position, n (% of group)
Lewinnek’s safe zone	38 (95.0)	55 (68.8)	OR: 8.6 (1.9 to 38.6)	0.002†
Callanan’s safe zone	37 (92.5)	53 (66.3)	OR: 6.3 (1.8 to 22.3)	0.003†

^*Independent-samples t-test.

^†Fisher's exact test.

CI, confidence interval; Diff, difference; mTHA, manual total hip arthroplasty; OR, odds ratio; rTHA, robotic assisted total hip arthroplasty.