Pure high-offset stems can cause an unexpected increase in femoral length in robotic-assisted primary total hip arthroplasty

Table 2 Rate and degree of leg length difference between each implant option, n (%)

Leg length difference in millimeters	Median (mm)	0	1	2	3	4	5
Standard vs high offset	1	5	35	3	-	-	-
High offset vs plus head	2	-	-	29	13	1	-
Standard vs plus head	3	-	-	-	31	11	1

Where standard denotes a standard insignia stem with a neutral head, high-offset denotes a high-offset insignia stem with a neutral head, and plus head denotes a standard insignia stem with a + 5 mm head.