A 20-year-old woman fell while playing volleyball and incurred a subtrochanteric fracture of her right femur (Figure 1). The patient had the following typical imaging manifestations of OP: increased radiation density of the entire skeleton, absence of medullary canals, appearance of a "thick Jersey spine" or "sandwich vertebrae" caused by thickening of the vertebral endplates, and several sclerotic concentric bands (bone-within-bone) in the iliac wing (Figure 2A). Radiographs of the right knee showed no "Erlenmeyer flask" deformity of the distal femur (Figure 2B). She had no cranial and facial distortions or syndactylies of the fingers and toes, but she was short (145 cm). Laboratory examination results showed normal hematological parameters, thyroid hormone levels, and alkaline phosphatase concentration. There was no evidence of skeletal deformities, hepatosplenomegaly, or cranial nerve disturbances. The patient had no previous history of fractures, anemia, recurrent infections, or bone pain. The patient was diagnosed with ADO type II (known as Albert-Schonberg disease or marble bone disease). The X-ray examination results of her parents were normal, and they had no history of fractures. The family history of previous generations was unknown. The patient and her parents refused to undergo genetic examinations.
As access to the intramedullary canal may not have been possible in this patient, we chose to use a DHS instead of intramedullary nailing. The procedure was technically challenging. The patient was placed in the supine position on a fracture traction table under general anesthesia. The fracture was reduced under fluoroscopic visualization. New sharp drill bits were used, as blunt drill bits were more likely to break. Saline was continuously applied to help keep the drill bit cool to prevent bone necrosis and drill bit breakage. It took 30 minutes to create the hole and insert a guidewire for the lag screw. Reaming along the guidewire was also difficult and time-consuming. The sclerotic bone produced excessive resistance to tapping. During the tapping process, the surgeon felt a sudden cracking sensation through the handle. A femoral neck fracture was detected by fluoroscopy. The nondisplaced fracture was located in the middle of the femoral neck, and the lag screw provided adequate stable fixation and compression. Therefore, we decided to proceed with the original surgery plan. Subsequently, the lag and plate were attached (Figure 3A and B). During the surgery, a cortical screw and six drill bits were broken, and a few guidewires were bent.
The patient was instructed to carry out active hip and knee joint training from the first postoperative day and used crutches to walk without placing weight on the affected limb for 7 days postoperatively. The patient had obtained 90  active hip flexion at 3 weeks postoperatively. She was discharged on crutches and instructed not to bear weight on the affected limb until the fracture had healed. Routine postoperative clinical and radiological follow-up examinations were performed. At 12 months postoperatively, there was complete healing of the fractures on X-ray examination, and the patient was allowed to commence full weightbearing (Figure 4A and B). At 2 years postoperatively, the patient was pain-free with full range of motion of the hip and had returned to work.