Fig. 3

Planning and representative computed tomography images. a A screenshot of the preoperative planning. b Coronal computed tomography image shows a bone defect at the drilling route and implanted region 1 day postoperatively. The yellow dashed line shows the border of the osteonecrotic area of the femoral head. c In contrast, apparent bone regeneration of the osteonecrotic area is observed at 1 year postoperatively (yellow arrow). The normal contour of the femoral head is maintained. d Apparent bone regeneration of the osteonecrotic area is observed in the implanted region (yellow arrow) and drilling route (yellow arrowheads) at 2 years postoperatively. Normal contour, thick trabecular bone, and bone regeneration of the drilling route can be observed