Spinal Augmentation for Vertebral Compression Fractures

Workup for Vertebral Compression Fractures

Patients with VCF often present with a chief complaint of sudden back pain. Back pain exacerbated by movement is consistent with an acute vertebral body compression fracture. On physical examination, midline tenderness to palpation may indicate vertebral body compression fracture. Diagnosis of compression fracture can be confirmed on x-ray by the characteristic wedge shape of the vertebral body. Computed tomography (CT) can further enhance possible missed fractures on plain film and demonstrate a more detailed degree of fracture. Magnetic resonance imaging (MRI) is used to determine compromise when neurological structures are involved. MRI is also helpful to determine the acuity of a fracture. Both CT and MRI conversely can be used to help rule out the diagnosis of VCF. In particular, the MRI short tau inversion recovery sequence is useful in revealing edema seen in acute VCF. Alternatively, bone scan can be used in those patients that have contraindications to undergoing MRI. Once confirmed, first-line treatment of VCFs consists of pain management, physical therapy, and bracing. ^, This also includes reduction of all modifiable risk factors with adjunct pharmacology (i.e., bisphosphonates) to target the underlying processes causing decreased bone density. Although this has been shown to provide relief to most patients, a few are still left with obstinate pain. In the past, patients were left with limited options from the surgical specialties in finding relief from VCFs. Operative management has traditionally been reserved for cases involving compression of neural elements. Open surgical procedures are trickier, as surgical hardware is more difficult to place safely within bone that has been ravaged by osteoporosis. Furthermore, patients in this population, which tends to include a high percentage of the elderly, may not be candidates for such an invasive procedure because of medical comorbidities.

Thus for many years patients were left in incredible pain, with few options remaining. This void in patient care was eventually filled by two revolutionary procedures, vertebroplasty and (subsequently) kyphoplasty. The exact mechanism of pain relief from vertebral augmentation is not exactly understood. It has been postulated that there are analgesic effects from mechanical stabilization of the fractured vertebral body and thermal ablation of intraosseous nerve fibers because the polymethylmethacrylate (PMMA) undergoes exothermic reaction when it polymerizes and transitions from a liquid to a solid form. The enormous demand for VCF treatment outside of standard medical therapy is evidenced by the astonishing number of these surgeries performed. From 2005 to 2010, some 307,050 total vertebroplasty and kyphoplasty procedures were performed in the United States alone. More recently, two new approaches to vertebral augmentation with metal implants have been introduced in United States following noninferiority randomized controlled trials (RCTs) performed in Europe. These will be discussed further later.

Vertebroplasty

Vertebroplasty ( Table 134.1 ) is a minimally invasive procedure that consists of percutaneous injection of a chemical cement agent that fills fracture defects in the vertebrae. The foundations of this vertebral augmentation procedure date to 1987 when Galibert and Deramond reported the first vertebroplasty. The French team pioneered the procedure in the treatment of C2 compromise by a hemangioma. ^, A transpedicular approach with subsequent injection of the bone cement PMMA into the hemangioma-ridden bone was found to ease the associated pain and instability.