Spinal osteoarthritis is a common degenerative condition that affects the joints of the spine, leading to back pain and stiffness. It occurs when the cartilage—the smooth, cushioning material between the bones in the spine—gradually wears down over time. This loss of cartilage causes the bones in the spine to rub against each other, which results in inflammation, pain, and reduced mobility.
The spine is made up of a series of vertebrae stacked on top of each other, separated by intervertebral discs and connected by facet joints. These facet joints are small joints located at the back of the spine that help stabilize it and allow for smooth movement like bending and twisting. In spinal osteoarthritis, these facet joints are often the primary sites of degeneration. As the cartilage in these joints deteriorates, the bones can develop bony growths called osteophytes or bone spurs, which further restrict movement and can irritate nearby nerves.
The process of spinal osteoarthritis typically begins with age-related wear and tear. Over years of use, the cartilage thins and loses its ability to cushion the joints effectively. This can be accelerated by factors such as previous spinal injuries, repetitive stress from certain activities or occupations, genetic predisposition, and obesity, which increases mechanical load on the spine.
As the cartilage wears away, the joint space narrows, causing the vertebrae to come closer together. This leads to increased friction and inflammation within the joint. The inflammation causes swelling and pain, which is often described as aching, throbbing, or sharp, especially with certain movements like bending backward, twisting, or prolonged activity. The stiffness is usually worse in the morning or after periods of inactivity and may improve with gentle movement.
In addition to pain and stiffness, spinal osteoarthritis can cause other symptoms depending on the severity and location of the degeneration. For example, if bone spurs or swollen joints press on nearby spinal nerves, this can lead to nerve compression symptoms such as numbness, tingling, or weakness in the arms or legs. This condition is sometimes called radiculopathy. In severe cases, if the spinal cord itself is compressed, it can cause more serious neurological problems like difficulty with coordination or bladder and bowel control.
The lumbar (lower back) and cervical (neck) regions of the spine are most commonly affected by osteoarthritis because they bear the most weight and have the greatest range of motion. People with lumbar spinal osteoarthritis often experience lower back pain that may radiate into the buttocks or legs, while cervical osteoarthritis can cause neck pain and stiffness, sometimes accompanied by headaches or pain radiating into the shoulders and arms.
Spinal osteoarthritis also affects the overall function of the spine. As the joints become stiff and painful, people may change the way they move to avoid discomfort, which can lead to muscle weakness, imbalance, and further strain on other parts of the spine or body. The reduced range of motion can make everyday activities like turning the head, bending, or lifting difficult.
The pain from spinal osteoarthritis is typically worse with activity and improves with rest, but prolonged inactivity can also cause stiffness and discomfort. Weather changes, such as cold or damp conditions, may exacerbate symptoms for some individuals.
In summary, spinal osteoarthritis causes back pain primarily through the breakdown of cartilage in the facet joints and other spinal joints, leading to bone-on-bone contact, inflammation, joint swelling, and sometimes nerve compression. This results in pain, stiffness, reduced mobility, and in some cases, neurological symptoms. The condition develops gradually, often related to aging and wear and tear, but can be influenced by injury, genetics, and lifestyle factors. Managing spinal osteoarthritis involves addressing pain and inflammation, maintaining mobility through exercise, and sometimes medical or surgical interventions depending on severity.