Low back pain is one of the most common reasons patients present to their physician. In fact, up to 84% of adults will experience low back pain at some point in their lives. While for most patients, the episodes are self-limited, there are more concerning causes of back pain requiring immediate attention such as vertebral compression fractures (VCFs). It is reported that up to 50% of women and 25% of men will have a VCF in their lifetime which correlates to approximately 1 to 1.5 million vertebral compression fractures per year in the United States. VCFs are directly correlated with increasing age and incidence of osteoporosis. As our population continues to grow older, these numbers will continue to grow.
Classically, VCFs result from an axial/compressive or flexion load on a weakened/osteoporotic vertebral body. This type of load places a large force on the anterior half of the vertebral body, making it the most common site of injury. Compression here produces the classic wedge-shaped deformity. The resulting kyphotic deformity may alter the biomechanics of the spine, placing strain on other neighboring structures even after the fracture is healed.
Patients with acute VCFs often present with severe pain. While management of pain associated with these fractures is not standardized, common strategies include activity modification, analgesics, and postural bracing. Often, these treatment modalities are sufficient to control the pain. However, if the pain is persistent and uncontrolled, other modalities may be considered to help prevent progression to chronic pain and disability. Chronic pain associated with VCFs is more difficult to manage because the pain is no longer related to the fracture itself but also to the strain on spinal muscles and ligaments secondary to the resulting kyphosis. Patients with moderate to severe pain that is functionally limiting and not responding to more conservative care may benefit from kyphoplasty if they are an appropriate candidate.
What is Kyphoplasty?
Kyphoplasty is a minimally invasive procedure performed under fluoroscopy for the management of acute VCFs (<6 weeks old). In order to determine if this is an appropriate procedure, a physician will first conduct a complete history and examination and then interpret pertinent imaging including MRI or CT. The intervention then typically has 5 main steps:
- The patient is positioned prone and then typically given conscious sedation. The skin will then be prepped and draped.
- After injecting local anesthetic, the physician uses fluoroscopy to insert a trocar (hollow needle) through the pedicle into the vertebral body. Sometimes a mallet is used to tap in the trocar.
- The physician creates a working channel in the vertebrae with a drill and then inserts an inflatable balloon. The balloon is inflated in an attempt to restore vertebral height and reduce kyphosis. The balloon is then deflated and withdrawn leaving an empty cavity within the vertebral body.
- Acrylic bone cement is then injected slowly into the vertebrae where it hardens and binds to the bone. This stabilizes the fracture and prevents further collapse.
- The trocar is withdrawn, and the site is covered with a bandaid. The patient remains prone until the cement hardens.
How does a Kyphoplasty improve pain?
There are several theories regarding the analgesic effect of kyphoplasty. The first is related to mechanical stabilization of the weakened/fractured vertebral body. In addition, reducing the kyphosis created by the fracture leads to less muscular and ligamentous strain associated with abnormal spine biomechanics. Lastly, the cement undergoes an exothermic (heat-releasing) reaction when it hardens; the ensuing thermal damage to the intraosseous nerve fibers within the vertebral body may also lead to pain relief.
Physicians trained in performing this procedure include Board-Certified Physical Medicine and Rehabilitation specialists including the physicians at Desert Spine and Sports Medicine as well as Anesthesiologists and Interventional Radiologists.
Kyphoplasty is a minimally invasive procedure which may be helpful in treating uncontrolled pain associated with a VCF. It is important to note, that this procedure is not appropriate for all patients. As board-certified specialists in Physical Medicine and Rehabilitation (PM&R), we are experts at evaluating and managing various causes of back pain including VCFs. Here at Desert Spine and Sports Physicians, we take the time to determine the most appropriate, evidence based, non-surgical treatment for each patient. If you have any further questions, feel free to contact us at Desert Spine and Sports Physicians to see if this procedure is right for your patient.