Osteoporosis | How Does it Affect the Spine?

Osteoporosis is a medical condition characterized by low bone density and deterioration of bone tissue. As bones become weaker, the risk of fracture increases – even from minor bumps or falls. Osteoporosis can lead to painful spinal fractures, loss of height, and spine deformities.

What is Osteoporosis?

Osteoporosis is a progressive bone disease where bone resorption occurs faster than formation, causing bone loss and increased risk of fractures.

There are two main classes:

Primary osteoporosis – Directly related to aging and estrogen changes. This comprises:

• Postmenopausal osteoporosis: Accelerated trabecular bone loss from estrogen decline after menopause, mostly affecting women.
• Senile osteoporosis: Gradual bone loss in advanced age due to slowing of bone formation process, occurring in both elderly women and men.

Secondary osteoporosis – Caused by other diseases or medications affecting bone health, like glucocorticoid therapy, hyperthyroidism, chronic inflammation from rheumatoid arthritis etc. Lifestyle factors like smoking, poor nutrition, alcohol overuse and inadequate physical activity also contribute by interfering with bone remodeling.

Anatomy and Physiology of the Spine

Spinal Column Components

The spine, also called the spinal column or vertebral column, consists of 33 vertebrae stacked upon each other, providing core support for the body. Between vertebrae are spinal discs that act as shock absorbers, and facet joints link the vertebrae and permit back flexibility. The spinal canal houses and protects the spinal cord.

Bone Remodeling Process

Bone is dynamic tissue that undergoes continuous remodeling through two processes:

Formation: Specialized cells called osteoblasts form new bone tissue

Resorption: Other cells called osteoclasts break down and absorb older bone

In youth, formation outpaces resorption, increasing bone mass. But with aging, resorption accelerates while formation slows, leading to bone loss.

Peak Bone Mass

By our 20s, bone formation and resorption balance out. We reach peak bone mass, having the greatest bone density and strength in our lifetimes. Building higher peak bone mass helps prevent osteoporosis later. Genetics determines potential peak bone mass, but nutrition, exercise, hormones and lifestyle factors also play key roles.

Osteoporosis and the Spine

Bone Loss Patterns in The Spine

In women, bone loss surges in the first 5 years after menopause due to plummeting estrogen, drastically declining bone mineral density in the spine. Men show gradual bone loss in aging.

Spinal Fractures

With advanced bone loss, the front portions of vertebrae can crack or collapse from even minor stresses like bending or coughing. These spinal compression fractures can cause:

• Sudden severe back pain
• Height loss as vertebrae crumple
• Limited mobility and activity

Underlying factors like low calcium, smoking, and corticosteroid use increase fracture risks.

Spinal Deformities

Spinal deformities may impair balance, mobility and functioning. The spine’s curvature can distort with multiple compression fractures, leading to:

Kyphosis: Excessive rounding (hunching) of the upper back

Scoliosis: Abnormal sideways spine curvature

Lordosis: Exaggerated arch inward of the lower back

Complications and Outcomes

Without preventative care, spinal osteoporosis can create cascading health issues:

Chronic Pain – Fractures trigger severe localized pain, persisting for months. Vertebral collapse also stresses other spine areas, causing chronic discomfort.

Limited Mobility – Fear of pain limits activity. Poor posture and balance from deformities further hamper mobility. Mobility aids may eventually become necessary.

Respiratory Issues – The ribs connect with the thoracic spine in back. Fractures and kyphosis can restrict breathing.

Spinal Stenosis – Fractured bone overgrowth crowds and compresses the spinal nerves. This commonly causes numbness, tingling and weakness in limbs. Severe cases prompt urinary or bowel incontinence.

Disability – As pain, limited mobility and other effects compound, injury risks and loss of independence increase. Support for daily activities may ultimately become essential.

Diagnosis and Testing

Since spinal osteoporosis lacks obvious symptoms initially, various methods help evaluate bone health and fracture risks:

Bone Mineral Density (BMD) Tests

BMD scans precisely measure bone density in the spine, hip and sometimes wrist to diagnose osteoporosis and assess risks.

Imaging Tests

X-rays reveal fractures, height loss or deformities.
CT scans provide 3D spine images, assessing bone quality.
MRI scans are best for viewing compressed nerves from fractures or bone overgrowth.

Laboratory Tests

Blood and urine tests help diagnose contributing factors like vitamin D deficiency, thyroid imbalance or excessive bone turnover.

WHO Fracture Risk Assessment Tool (FRAX)

This algorithm calculates 10-year probability estimates for major osteoporotic fractures using various risk factors.

Treatment and Management

Halting bone loss and preventing further spinal damage involves multifaceted approaches.

Medications

Bisphosphonates (alendronate, risedronate) inhibit bone resorption by osteoclasts to maintain bone density. They cut spinal fracture rates by 50-70%.

Denosumab achieves similar fracture risk reductions by blocking osteoclast formation.

PTH Analogues (teriparatide) stimulate osteoblasts for bone formation, used for severe cases.

Lifestyle Modifications

Diet – Ensure sufficient calcium and vitamin D intake.

Exercise – Weight-bearing and muscle-strengthening exercises stimulate bone growth factors.

Fall Prevention – Balance training and home safety modifications reduce risks.

Smoking Cessation – Smoking heightens bone loss and fracture risks. Quitting smoking provides major benefits.

Surgery

If medications and lifestyle changes fail, surgical interventions include:

Vertebroplasty – Injecting bone cement into the fractured vertebra for stabilization.

Kyphoplasty – Inserting balloons first to restore vertebral height before the bone cement.

Conclusion

Bone loss from osteoporosis greatly heightens risks of usually painful spinal fractures and worrisome deformities limiting mobility. But early detection and proactive treatment can strengthen bone, curbing further deterioration to preserve quality of life. Consistently taking bone-protective medications combined with weight-bearing exercises and proper nutrition offers the best protection. With vigilance and proper care, the negative impacts of spinal osteoporosis can be minimized.