Table II.

This table shows the difference in range of motion (flexion) between the cone-shaped range of motion (cylindrical neck) and quatrefoil-shaped range of motion (trapezoidal neck). In this table, the acetabular abduction angle is 40° and anteversion is 20°, while the femoral stem anteversion is 20°.

Head size, mm	NSA, °	ER (-10°)			ER (0°)			ER (10°)			ER (45°)			ER (90°)			IR (90°)			IR (110°)
		Cone	Q	Diff	Cone	Q	Diff	Cone	Q	Diff	Cone	Q	Diff	Cone	Q	Diff	Cone	Q	Diff	Cone	Q	Diff
28	127	31.1	31.6	0.5	43.1	44.7	1.6	56.5	57.8	1.3	96.1	98.2	2.0	101.0	103.6	2.6	47.4	51.6	4.2	33.4	34.2	0.8
32	127	32.9	34.9	2.0	45.2	46.9	1.7	58.7	61.1	2.4	98.3	100.9	2.6	102.5	105.0	2.5	49.0	54.5	5.5	35.0	36.4	1.4
36	127	34.7	36.0	1.3	47.1	49.1	2.0	60.8	63.3	2.5	100.2	102.3	2.0	104.0	106.4	2.3	50.5	56.7	6.2	36.4	37.8	1.4
40	127	36.3	38.2	1.9	48.8	51.3	2.5	62.7	65.5	2.7	102.1	105.0	2.9	105.4	107.7	2.3	51.8	58.2	6.4	37.7	39.3	1.5
28	132	36.2	37.1	0.9	49.5	51.3	1.7	63.9	65.5	1.5	103.0	105.0	2.0	102.5	105.0	2.5	47.1	50.9	3.8	30.5	30.5	0.0
32	132	38.3	39.3	1.0	51.7	53.5	1.7	66.4	68.7	2.3	105.4	107.7	2.3	104.2	107.7	3.5	48.8	53.8	5.0	32.3	32.7	0.4
36	132	40.3	41.5	1.2	53.9	55.6	1.7	68.7	72.0	3.3	107.6	110.5	2.9	105.8	109.1	3.3	50.4	57.5	7.1	33.9	34.9	1.0
40	132	41.9	43.6	1.7	55.7	58.9	3.2	70.8	73.1	2.3	109.5	111.8	2.3	107.2	109.1	1.9	51.8	59.6	7.9	35.3	36.4	1.0
28	135	39.6	40.4	0.8	53.7	54.5	0.9	68.9	70.9	2.0	107.6	109.1	1.5	103.5	105.0	1.5	46.8	50.2	3.4	28.4	28.4	-0.1
32	135	41.8	42.5	0.8	56.1	58.9	2.8	71.6	74.2	2.6	110.0	111.8	1.8	105.3	107.7	2.5	48.5	55.3	6.8	30.3	30.5	0.2
36	135	43.9	45.8	2.0	58.4	61.1	2.7	74.1	76.4	2.3	112.4	115.9	3.5	106.9	110.5	3.5	50.2	57.5	7.3	32.1	32.7	0.7
40	135	45.6	48.0	2.4	60.3	63.3	2.9	76.4	79.6	3.3	114.5	118.6	4.1	108.4	110.5	2.0	51.6	58.9	7.3	33.6	34.2	0.6

ER, external rotation; IR, internal rotation; NSA, neck shaft angle; Q, quatrefoil.