SACRAL INSUFFICIENCY FRACTURES

Primary osteoporosis is the most common cause of sacral insufficiency fractures (SIFs). Therefore, a multidisciplinary team approach is necessary for treatment of the fracture and the underlying biologic pathology, as well as prevention of future fragility fractures. The presentation of SIFs typically includes lower back or buttock pain after a ground-level fall or without an identified trauma. Symptoms often have an insidious onset and are nonspecific; consequently, a delay in diagnosis and treatment is common. Clinicians need to have a high index of suspicion, particularly in high-risk patients. Postmenopausal women who are >55 years of age are the most common demographic affected by SIFs. Other risk factors include osteoporosis, history of a prior fragility fracture, local irradiation, long-term corticosteroid use, rheumatoid arthritis, metabolic bone disorders, vitamin D deficiency, pregnancy, history of prior multilevel spinal fusion, and malignancy. Typical imaging on computed tomography (CT) shows sclerosis of cancellous bone in the sacral ala, with or without a discrete fracture line or displacement. Magnetic resonance imaging is more sensitive than CT and shows hypointense signal on T1-weighted sequences and hyperintensity on T2-weighted or short tau inversion recovery sequences. The treatment of SIFs is dependent on the severity of symptoms, fracture displacement, and instability of the pelvis. Accepted treatments include nonoperative rehabilitation, sacroplasty, iliosacral screw fixation, transsacral bar or screw fixation, transiliac internal fixation, and lumbopelvic fixation.