Baastrup’s disease is a common cause of lower back pain, arising from mechanical irritation and subsequent inflammation between specific parts of the vertebrae. The condition is a degenerative process that develops over time, and the pain it causes can range from mild discomfort to a significant, chronic issue that affects daily life. While it is rarely a medically urgent situation, the seriousness of Baastrup’s disease lies in its capacity to severely diminish a person’s quality of life if the symptoms are left unmanaged.
Understanding the Condition
Baastrup’s disease describes the phenomenon where the bony projections at the back of the spine, known as the spinous processes, are situated too closely and begin to touch one another. This proximity has earned the condition its more descriptive common name: “Kissing Spine” syndrome. The contact typically occurs in the lumbar spine, with the space between the fourth and fifth lumbar vertebrae (L4-L5) being the most frequently affected site.
This repetitive, abnormal contact between the adjacent bones creates friction and mechanical pressure, which leads to degenerative changes. Over time, this friction causes inflammation, sclerosis (hardening) of the bone, and the eventual flattening and enlargement of the spinous processes where they articulate. The constant rubbing can also lead to the formation of an adventitious bursa, a fluid-filled sac that develops to cushion the irritated area, which itself can become inflamed and painful.
The underlying cause of this close approximation is often linked to degenerative changes in the spine, such as disc degeneration or excessive lordosis, which is an exaggerated inward curve of the lower back. This condition is most common in older adults, although it can also affect younger individuals, particularly athletes whose activities involve repetitive hyperextension of the back. The changes associated with Baastrup’s disease are considered a form of spinal degeneration resulting from mechanical stress.
Assessing the Severity and Impact
The hallmark symptom is localized, midline lower back pain that is predictably aggravated by movements that bring the spinous processes closer together. Activities that involve extending the spine, such as standing for long periods, walking uphill, or leaning backward, tend to increase discomfort significantly.
Conversely, the pain is typically relieved by flexion, which is the act of bending forward, as this movement separates the touching bones. Patients often report finding relief when sitting down or leaning over a shopping cart, a posture that reduces the pressure on the irritated spinal structures. Tenderness is also usually present upon direct finger pressure over the affected area of the spine.
While the condition is not life-threatening, its seriousness lies in its potential to create chronic, debilitating pain that severely affects a person’s quality of life and mobility. In some more advanced cases, the degenerative changes, such as the formation of an interspinous bursa, can extend inward and press on the spinal canal, potentially causing symptoms like neurogenic claudication. This can lead to leg pain or numbness, suggesting a more complex issue that requires prompt medical attention.
Management and Long-Term Outlook
Management typically follows a conservative, step-wise approach, aiming to alleviate pain and restore function. Initial treatment focuses on non-invasive methods, including activity modification to avoid painful extension movements and the use of anti-inflammatory medications. Non-steroidal anti-inflammatory drugs (NSAIDs) are often prescribed to help reduce the localized inflammation and pain at the site of the touching spinous processes.
Physical therapy plays a central role in long-term management, focusing on strengthening the core muscles to improve posture and reduce excessive lumbar lordosis. The physical therapist will typically guide the patient through flexion-based exercises, which help to open the space between the vertebrae and relieve the pressure on the affected area. Weight management and postural education are also important components of conservative care to minimize mechanical stress on the spine.
If conservative measures do not provide adequate relief, interventional procedures are often considered. Corticosteroid injections, delivered precisely into the inflamed interspinous space, can significantly reduce pain and inflammation for an extended period. For the small percentage of individuals with persistent, severe pain that does not respond to non-surgical treatments, surgical options may be discussed. These procedures typically involve partially removing or reshaping the spinous process to create space between the vertebrae. The long-term outlook for Baastrup’s disease is generally positive, as the condition is highly manageable, and most patients achieve significant pain relief and improved function through non-surgical methods.