Arthritis and Diseases That Affect the Back
From cartilage breakdown to muscle inflammation – problems that may be to blame for back pain.
Many forms of arthritis and related conditions that affect the joints, muscles and/or bones can cause problems like pain, stiffness and swelling in the back. While any part of the back can be affected, the lower back is the most common site of arthritis back pain, most likely because it bears more of the body's weight.
Several forms of arthritis – collectively referred to as the spondylarthropathies (meaning spinal arthritis)– primarily affect the spine. These include:
• Ankylosing spondylitis. Ankylosing spondylitis is a chronic inflammatory disease that primarily affects the spine, particularly the sacroiliac joints near the pelvis, and the hip joints. Ankylosing is a term meaning stiff or rigid and spondylitis means inflammation of the spine.
Enthesitis (inflammation of the place where ligaments and muscles attach to bones) accounts for much of the pain and stiffness of ankylosing spondylitis. This inflammation eventually can lead to bony fusion of the joints (where the fibrous ligaments transform to bone, and the joint permanently grows together).
Other joints can also develop synovitis (inflammation of the lining of the joint), with lower limb joints more commonly involved than upper-limb joints.
• Reactive arthritis. Reactive arthritis is a chronic form of arthritis that often occurs following an infection of the genital, urinary or gastrointestinal system. Features of reactive arthritis include inflammation of the joints, eyes and structures within the gastrointestinal or genitourinary tracts, such as intestines, kidneys or bladder.
• Psoriatic arthritis. Psoriatic arthritis is a form of arthritis accompanied by the skin disease psoriasis. The skin disease often precedes the arthritis; in a small percentage the joint disease develops before the skin disease. For about 20 percent of people with psoriatic arthritis, the disease involves the spine. In some cases, bony overgrowth can cause two or more vertebrae to grow together, or fuse, causing stiffness.
• Juvenile Spondylarthropathy. Also called juvenile-onset spondyloarthritis (spinal arthritis), this term is used to describe spondylarthropathies that begin before age 16. In addition to affecting the spine, they may cause pain and inflammation in the joints of the pelvis, hips, ankles and knees. They may also affect other body organs such as the eyes, skin and bowels.
• Enteropathic arthritis. This is a form of arthritis that occurs in about 5 percent of people with inflammatory bowel disease, which includes ulcerative colitis and Crohn's disease. It commonly affects the sacroiliac joints, causing lower back pain.
Other forms of arthritis and related conditions that can affect the back include:
• Osteoarthritis. The most common form of arthritis of the back, osteoarthritis is a chronic condition characterized by the breakdown of the cartilage that cushions the ends of the bones where they meet to form joints. In the spine, this breakdown occurs in the cartilage of the facet joints, where the vertebrae join. As a result, movement of the bones can cause irritation, further damage and the formation of bony outgrowths called spurs. These spurs can press on nerves, causing pain. New bone formation can also lead to narrowing of the spinal canal, known as spinal stenosis.
• Rheumatoid arthritis. Rheumatoid arthritis is a chronic inflammatory disease of the joints that occurs when the body’s immune system – which normally protects us from infection – mistakenly attacks the synovium, the thin membrane that lines the joints. Although rheumatoid arthritis most commonly affects the hips, knees, hands, wrists, feet, elbows and ankles, it can also affect the facet joints in the spine, causing pain and, in severe cases, destruction of the joints. This may allow the upper vertebra to slide forward on top of the lower vertebra, a condition called spondylolisthesis. The slipped vertebra may put pressure on the spinal cord and/or the nerve roots where they exit the spine.
• Gout. Gout is a form of arthritis that occurs when excess uric acid, a bodily waste product circulating in the bloodstream, is deposited as needle-shaped monosodium urate crystals in tissues of the body, including the joints. For many people, the first symptom of gout is excruciating pain and swelling in the big toe – often following a trauma, such as an illness or injury. Subsequent attacks may occur off and on in other joints, primarily those of the foot and knee. Less commonly gout can affect the spine, causing extreme pain, numbness and tingling. It can be confused with a spinal infection.
• Infectious arthritis. Also called septic arthritis, infectious arthritis refers to arthritis that is caused by an infection within a joint. It can occur in the facet joints of spine. Infectious arthritis is often caused by bacteria that spread through the bloodstream to the joint. Sometimes it is caused by viruses or fungi.
• Polymyalgia rheumatica. An inflammatory disorder that causes widespread muscle pain and stiffness, polymyalgia rheumatica mainly affects the neck, shoulders, upper arms, lower back, thighs and hips. The disease often comes on suddenly and resolves on its own in a year or two.
• Fibromyalgia. An arthritis-related condition, fibromyalgia is a syndrome of chronic, widespread muscle pain and fatigue, which can be debilitating. The lower back is a common site of fibromyalgia pain.
• Osteoporosis. Osteoporosis is a condition in which the bones loose so much mass that they become brittle and prone to break with slight trauma. The condition, which can occur with aging, inactivity, a low-calcium diet or use of corticosteroid medications, commonly affects the spine. When this occurs in the spine, the inner spongy bone and more solid outer portion of the vertebrae become porous. The weakened vertebrae can break – an injury called a compression fracture – and lose about one-half of their height. In most cases, compression fractures, are painful. In some cases, the resulting back pain is severe. Usually, the pain resolves within a few weeks, but for some people, it is long-lasting.
• Spinal stenosis. Literally meaning "spinal narrowing," spinal stenosis can occur when changes in arthritis lead to bony overgrowth of the vertebrae and thickening of the ligaments. This can occur with osteoarthritis or ankylosing spondylitis. If a significant overgrowth occurs, it can cause the spinal column to narrow and press on the nerves housed within. Because the affected nerves have many functions, the condition may cause diverse problems in the lower body, including back pain, pain or numbness in the legs, constipation or urinary incontinence.
• Paget's disease of bone. Paget’s disease is a chronic disorder in which excessive breakdown and formation of bone causes the bones to become enlarged, misshapen and weakened. The disease usually does not affect the entire skeleton, but just one or a few bones. The vertebrae are among the bones most commonly affected by Paget's disease.
• Sciatica. This is inflammation of the sciatic nerve. The largest nerve in the human body, the sciatic nerve runs from the lower part of the spinal cord, through the buttock and down the back of the leg to the foot. The most common causes of sciatica include compression of the nerve where it exists the spine by a herniated disc, or a rupture of one of the structures that cushions the vertebrae in the spine. Sciatica may be felt as a sharp or burning pain that radiates from the hip. It may also be accompanied by low back pain.
• Scoliosis. Instead of running straight up the center of the back, a spine with scoliosis twists to one side. Scoliosis can be classified as true (meaning it has to do with abnormal development of the spine) or functional (meaning its cause is not directly related to the spine). Functional scoliosis may occur when a discrepancy in leg length causes the pelvis to tilt to one side to compensate. The cause of true scoliosis is largely unknown, although doctors suspect that it may be the result of imbalanced growth in childhood.