Paget’s disease, also known as osteitis deformans, is the second most common metabolic bone disorder in the United States (behind osteoporosis). Paget’s disease occurs when your bone cells don’t function properly, resulting in deformed, enlarged, and fragile bones. The bones of your spine (vertebrae) are susceptible to this condition.
Paget’s Disease and Your Spine
Paget’s disease begins with a malfunction in the two types of bone cells: osteoblasts and osteoclasts. Your bones are constantly undergoing a regenerative process where osteoclasts break down old bone, and osteoblasts build new bone in its place. When these cells work together in a balanced way, your bones are kept strong.
If you have Paget’s disease, the osteoclasts break down old bone at a faster rate than normal, which forces osteoblasts to work overtime. When this happens, the new bone is placed improperly, leading to deformity. The new bone is also more fragile than healthy bone, so it’s at greater risk of fracturing.
Among the most frequently affected Paget’s disease sites are the spinal bones (particularly those in your low back and sacrum) and pelvis. Paget’s disease can involve a single bone (monostotic) or multiple bones (polyostotic). Monostotic cases account for 10% to to 35% of total occurrences.
Paget’s disease typically affects people over the age of 55, and up to 3% of that population develops the disease.
Spinal Symptoms of Paget’s Disease
Many people who have Paget’s disease in their spine don’t know it. But, as the disease advances, the most common spinal symptom is bone pain in the neck and/or back. The pain may feel dull, persistent, and worsen at night.
If Paget’s disease in your back causes spinal cord compression, you may experience neurologic symptoms like tingling, numbness, difficulty walking, or bowel and bladder problems.
Cause of Paget’s Disease
Researchers don’t know the cause of Paget’s disease, but they suspect genetics and viral infection could be linked to the condition.
Spine-Related Complications of Paget’s Disease
Paget’s hallmark bone deformities can result in painful spine conditions, including spinal stenosis and kyphosis. Most notably, the disease makes you prone to spinal fractures due to the weak new bone produced by the overworked osteoblasts. Vertebral body compression fractures can cause spinal cord compression and nerve pain.
Paget’s disease has also been connected to degenerative joint disease, though researchers don’t fully understand the disorder’s association to joint changes. Types of spinal arthritis that may coexist with Paget’s include rheumatoid arthritis, spondylosis (spinal osteoarthritis), and ankylosing spondylitis.
Less commonly, Paget’s disease has been linked to some spinal tumors, including osteosarcoma.
Diagnosing and Treating Paget’s Disease
A physical exam may help diagnose Paget’s disease if symptoms are obvious, such as a hunchback due to kyphosis. However, many cases require imaging tests to get a closer look at your bones. Your doctor may order an X-ray of your spine to confirm a diagnosis, which will illuminate bone problems. For early stages of Paget’s, a bone scan will pick up initial deformities even better than an X-ray. CT scans or magnetic resonance imaging (MRI) may also be used for advanced cases.
Blood testing is also important in diagnosing Paget’s disease. The test, known as a bone-specific alkaline phosphatase test, can detect when your bones are regenerating at too fast a rate. This blood test is not only used during diagnosis but also helps monitor patients through treatment.
Paget’s disease is treated with medications called bisphosphonates. These medications help restore the normal function of osteoclasts and osteoblasts. Bisphosphonates can effectively manage your disease and reduce symptoms, but they do not cure Paget’s disease. That’s why your doctor will want to continually monitor you to ensure the disease doesn’t reappear or worsen.
Living Well with Paget’s Disease
Advanced cases of Paget’s disease can cause spine problems, including spinal fractures. But, most people with Paget’s disease have good outcomes. When this bone disorder is managed with medication and regular follow-up appointments with your doctor, it shouldn’t come between you and a good quality of life.