Fig. 4

Illustration of the robot-assisted core decompression and bone graft. a, b Anteroposterior and lateral intraoperative fluoroscopic images of the hip were taken and input to the workstation. c, d Surgical trajectory for guidewire insertion on anteroposterior and lateral view of the hip. e Guide wire insertion. f Solid trephine insertion along the guidewire. g Hollow trephine insertion along the guidewire into the necrotic area of the femoral head. h, i Grafting of the cancellous bone using the grafting pipe with a funnel