Simplified Pedicle Subtraction Osteotomy for Osteoporotic Vertebral Fractures

Abstract

Background: In osteoporotic vertebral fractures (OVF) involving neurological symptoms and severe kyphosis, vertebral osteotomies are necessary but are associated with a high risk of complications.Methods: We performed a retrospective study. In 14 patients (mean age, 69.3 years old) with unstable thoracolumbar fractures associated with severe kyphosis, a posterior instrumentation with polymethylmethacrylate-augmented screws and a modified pedicle subtraction osteotomy (PSO) at the fracture level were performed to stabilize the spine and correct the kyphosis. The underlying principle behind the osteotomy's technique was to exaggerate the defect caused by the fracture and shorten the spine: (1) completion of a wide laminoforaminotomy, (2) use of successive reamers rotated in the pedicle at a 25 degrees angle in the axial plane to obtain its complete decancellation, (3) insertion of the reamers in a more medial orientation (55 degrees) to collapse the posterior wall, and (4) breakage of the lateral wall. Radiographic and clinical outcomes were analyzed pre- and postoperatively. Complications were reported.Results: Functional scores improved after surgery. Oswestry disability index and visual analog scale scores decreased significantly (33 and 4 points, respectively). Patient satisfaction rate reached 93%. Average postoperative regional vertebral kyphosis was decreased to 3.79 degrees. No dural tear or neurological injuries were observed. Blood loss of 920 mL (+/- 350 mL) and two mechanical complications were reported.Conclusions: OVF can lead to severe deformities. In osteoporotic bones, the use of sequential reamers can simplify the PSO technique, allowing for the shortening and stabilization of the spine without manipulating the dural sac. The risk of neurological injuries and blood loss is decreased.