Baastrup’s Disease, often a source of significant low back discomfort, is a common spinal condition. Individuals experiencing this pain frequently wonder if it is inherited or the result of wear and tear over time. Understanding the nature of this condition requires a close look at the mechanics of the spine, which reveals the truth about its development, diagnosis, and treatment.
Defining Baastrup’s Disease
Baastrup’s Disease results from the abnormal contact between the bony projections extending from the back of the vertebrae, known as spinous processes. The resulting friction and irritation between them give the condition its common alternative name: Kissing Spines. The condition most frequently affects the lumbar region, or lower back, typically occurring at the L4-L5 spinal levels.
The repetitive rubbing causes degenerative changes, which include the enlargement and flattening of the bone surfaces where they meet. This mechanical irritation often leads to the formation of an adventitious bursa, a fluid-filled sac, resulting in inflammation known as interspinous bursitis. The pain is typically localized to the midline of the back and worsens when the spine is extended, or bent backward.
The Role of Genetics Versus Degeneration
Baastrup’s Disease is overwhelmingly classified as a degenerative and mechanical condition rather than a hereditary one. The disease is intrinsically linked to chronic, age-related changes in the spine, particularly those that increase the physical contact between the spinous processes. While many spinal conditions have a strong genetic component, the onset of Baastrup’s Disease requires the physical process of mechanical wear and tear to initiate the pathological changes. The lack of direct genetic transmission distinguishes it from truly hereditary disorders. It is true that a person may inherit an anatomical structure that makes them more susceptible, such as a naturally deep inward curve of the lower back. However, this structural predisposition merely sets the stage for the degenerative process over time.
Key Contributing Factors to Development
The primary driver of Baastrup’s Disease is the excessive mechanical pressure placed on the interspinous ligaments and processes. This pressure is often generated by hyperlordosis, an exaggerated inward curve of the lower back that forces the spinous processes closer together. Advanced age is a significant factor, as the disease incidence rises sharply in older populations due to cumulative wear and tear.
Degenerative changes in the intervertebral discs also play a substantial role. As discs lose height, the distance between adjacent vertebrae decreases, causing the spinous processes to approximate and rub against each other. Mechanical stress from occupational or athletic activities that involve repetitive spinal extension, such as in gymnastics, can accelerate this process. Other factors, including obesity and a protuberant abdomen, contribute by shifting the body’s center of gravity and increasing the degree of lumbar lordosis.
Diagnosis and Management Approaches
Diagnosis begins with a clinical evaluation, where the physician notes the characteristic pain that improves with spinal flexion and worsens with extension. Imaging studies are necessary to confirm the diagnosis and rule out other causes of back pain. Standard X-rays often reveal the close proximity or contact of the spinous processes. Dynamic flexion-extension radiographs are often used to demonstrate the movement and mechanical nature of the contact. Magnetic Resonance Imaging (MRI) is considered the comprehensive tool, as it can show associated signs like interspinous bursitis, bone marrow edema, and sclerosis of the bony surfaces.
Management typically starts with conservative methods, including physical therapy focused on exercises that promote spinal flexion to increase the space between the bones. Anti-inflammatory medications are also used to reduce pain and inflammation. If symptoms persist, targeted percutaneous injections of corticosteroids can be administered directly into the affected interspinous space to provide pain relief. Surgical intervention, such as partial resection of the spinous processes to physically eliminate the contact, is reserved for severe cases that do not respond to conservative or interventional treatments.