Fig. 1

a, b Anteroposterior and frog-like radiographs of a 38-year-old male patient showing uneven density within the femoral head. c MRI T1WI showed femoral head necrosis. d OCM approach fenestration in the head and neck images of non-vascularized bone graft blocks occluding the bone window (black arrow). e Images of the ilium taken with subcutaneous tissue detached proximally from the same incision (black arrow). f, g Anteroposterior and frog radiographs of the hip at 3 months postoperatively showed increased bone density in the femoral head and good osteogenesis in the bone graft area. h At 6 months post-operation, the frontal radiograph of the hip joint showed good osteogenesis in the femoral head and swelling of the soft tissue around the hip due to high fever and pain in the operation area. i MRI T2WI showed synovial hyperplasia and edema in the joint. Edema of the muscle layer around the hip joint may indicate infection. j Original incision exposed the neck of the femoral head to visible intra-articular purulent secretions (black arrow). k Bone healing at the fenestration in the neck of the original femoral head (black arrow). l, m Anteroposterior and frog radiographs of the hip after debridement. n, o Anteroposterior and frog radiographs of the hip at the last follow-up show good osteogenesis of the bone graft region and stable femoral head