Typical patients in three groups
left idiopathic ONFH, ONFH
GROUP B

Group A: The patient has left-sided hormonal ONFH. The patient’s hip was fixed with a biodegradable magnesium screw (4.0 mm diameter, 30 mm long) in the PVIBGT. More details are shown in Figs. Pre-operative (Pre-operative (Group B: The patient has bilateral hormonal ONFH.The patient underwent bilateral PVIBGTs with two titanium screws. More details are shown in Figs. Pre-operative (CT and 3D reconstruction of a typical patient in Group B before surgery (Group C: The patient has left idiopathic ONFH. The patient underwent a left-sided PVIBGT without any screw (directly embedded iliac bone graft). More details are shown in Figs. Pre-operative (CT and 3D reconstruction of a typical patient in Group C before surgery (