The human spine is a complex column of 33 stacked bones called vertebrae, which provide support for the body and protect the delicate spinal cord. Each vertebra has a thick, cylindrical body in the front that bears the majority of the weight. When excessive force is applied, one of these vertebral bodies can fracture and collapse, a condition known as a compression fracture. This type of spinal injury is the most frequently occurring fracture of the spine, often causing significant pain and affecting overall mobility.
Defining the Wedge Compression Fracture
A wedge compression fracture is a specific type of collapse where the front portion of a vertebral body breaks down, while the back portion remains mostly intact. This uneven compression causes the bone to assume a distinctive wedge shape when viewed on a medical image. The fracture is typically the result of an axial load—pressure applied vertically along the spine—combined with a forward bending motion.
The resulting wedge shape means the structural integrity of the spinal canal, which houses the spinal cord, is usually preserved. Since the posterior column of the vertebra is undamaged, this fracture is generally considered stable. Wedge fractures most commonly affect the mid-back (thoracic) and the upper part of the lower back (lumbar) spine because these segments bear substantial weight. The fracture is formally defined when the height of the vertebral body is reduced by at least 15 to 20 percent compared to its original size or adjacent vertebrae.
Primary Causes and Risk Factors
The most common underlying cause is osteoporosis, a condition characterized by progressive bone mineral loss that makes the vertebrae fragile. When bones are weakened by this disease, the fracture is classified as pathological and can occur with minimal trauma. Simple daily activities, such as coughing forcefully or bending over, can generate enough pressure to cause a vertebral collapse.
The risk for this type of fragility fracture increases significantly with age and is particularly high for postmenopausal women due to hormonal changes. For younger, healthier individuals, a wedge compression fracture is typically caused by high-impact trauma. These injuries result from substantial force, such as a severe fall or a motor vehicle accident, which overwhelms the normal strength of the bone. Another risk factor is the presence of cancerous tumors that have metastasized to the spine, weakening the bone structure.
Recognizing Symptoms and Confirming Diagnosis
The clinical presentation often begins with the acute onset of sharp, localized back pain at the level of the injured vertebra. This pain typically intensifies when the individual stands or walks, as body weight compresses the fractured bone further. Lying flat on the back usually provides some relief, as this position unloads the damaged spinal column.
If multiple or chronic fractures occur over time, the gradual collapse of the vertebral bodies can lead to a visible change in posture. This chronic condition often manifests as a progressive forward curvature of the spine, known as kyphosis, sometimes referred to as a “dowager’s hump.” The accumulation of these fractures can also result in a noticeable loss of overall body height.
Diagnosis begins with a physical examination and a review of the patient’s medical history to assess for risk factors. The primary tool for confirming the injury is a lateral X-ray of the spine, which visualizes the characteristic wedge shape and quantifies the degree of vertebral height loss.
Imaging Techniques
If there is concern for instability or possible nerve involvement, a Computed Tomography (CT) scan may be performed to provide greater detail on the bone structure. A Magnetic Resonance Imaging (MRI) scan is sometimes used to check for soft tissue injury or to determine the age of the fracture by looking for bone marrow edema.
Management and Recovery Paths
For many stable wedge compression fractures, initial management focuses on conservative, non-surgical treatment to allow the bone to heal naturally. This approach typically involves a period of rest to reduce stress on the spine, followed by pain management, including nonsteroidal anti-inflammatory drugs (NSAIDs) or short-term use of opioid medication. A specialized back brace may be prescribed to temporarily immobilize the spine, which helps reduce pain and prevent further collapse while the bone mends.
If a fracture is severe, unstable, or causes persistent pain that does not respond to conservative care, surgical intervention may be considered. Two common, minimally invasive procedures are vertebroplasty and kyphoplasty. Both involve injecting medical-grade bone cement into the fractured vertebra to stabilize it. Kyphoplasty differs by first using a small balloon to attempt to restore some lost vertebral height before the cement is injected.
Recovery varies, but most conservative fractures heal within six weeks to three months. Following the initial healing phase, physical therapy is an important part of the recovery process, especially for older patients. Therapy focuses on strengthening the back and core muscles, improving posture, and restoring function to reduce the risk of future fractures.