Disorders of The Skeletal System, Bones and Joints

Common disorders of the skeletal system may be categorised as disorders of bones or disorders of joints.

Orthopaedics (or-tho-pe-diks) is the branch of medicine that specialises in treating diseases and abnormalities of the skeletal system.

Disorders of Bones

Fractures are broken bones. Fractures are the most common type of bone injury. Fractures are categorised as either complete or incomplete. There are also several specific subtypes, such as the examples noted here and in.

• Complete: The break is completely through the bone.
• Compound: A broken bone pierces the skin.
• Simple: A bone does not pierce the skin.

  Comminuted: The bone is broken into several pieces.

• Segmental: Only one piece is broken out of the bone.
• Spiral: The fracture line spirals around the bone.
• Oblique: The break angles across the bone.
• Transverse: The break is at right angles to the long axis of the bone.
• Incomplete: The bone is not broken completely through.
• Greenstick: The break is only on one side of the bone, and the other side of the bone is bowed.
• Fissured: The break is a lengthwise split in the bone.

  Osteomyelitis is an inflammation of bone and bone marrow caused by bacterial infection. It is treatable with antibiotics but not easily cured.

  Osteoporosis (os-te-o-po-ro ‘-sis) is a weakening of bones due to the removal of bone matrix, which increases the risk of fractures. This is a common problem in older persons due to inactivity and a decrease in hormone production. It is more common in postmenopausal women because of the lack of estrogens. Exercise and calcium supplements retard the decline in bone density. Therapy includes drugs that reduce bone loss or those that promote bone formation. However, such drugs must be used with caution because they can have serious side effects.

  Rickets is a disease of children that is characterised by a deficiency of calcium salts in the bones. Affected children have a bowlegged appearance due to the bending of weakened femurs, tibiae, and fibulae. Rickets results from a dietary deficiency of vitamin D and/or calcium. It is rare in industrialised nations.

  Disorders of Joints

  Arthritis (ar-thri ‘-tis) is the general term for many different diseases of joints that are characterised by inflammation, swelling (edema), and pain. Rheumatoid arthritis and osteoarthritis are the most common types.

  Rheumatoid (ru’-mah-toid) arthritis is the most painful and crippling type. It is an autoimmune disorder, in which the joint tissues are attacked by the patient’s own defences. The synovial membrane thickens, synovial fluid accumulates causing swelling, and articular cartilages are destroyed. The joint is invaded by dense irregular connective tissue that ultimately ossifies, making the joint immovable.

  Osteoarthritis, the most common type, is a degenerative disease that results from ageing and wear. The articular cartilages and the bone deep to the cartilages gradually disintegrate, which causes pain and restricts movement.

  Dislocation is the displacement of bones forming a joint. Pain, swelling, and reduced movement are associated with a dislocation.

  Herniated disc is a condition in which an intervertebral disc protrudes beyond the edge of a vertebra. A ruptured, or slipped, disc refers to the same problem. It is caused by excessive pressure on the vertebral column, which causes the nucleus pulposus, the centrally located gelatinous region of the disc, to protrude into the annulus, fibrosus, the perimeter of the disc. The protruding disc may place pressure on a spinal nerve and cause considerable pain.

  Sprains result from tearing or excessive stretching of the ligaments and tendons at a joint without a dislocation.

  Abnormal spinal curvatures are usually congenital disorders. There are three major types:

1. Scoliosis is an abnormal lateral curvature of the vertebral column. For some reason, it is more common in adolescent girls.
2. Kyphosis (ki-fo-sis) is an excessive thoracic curvature of the vertebral column, which produces a hunch-back condition.
3. Lordosis is an excessive lumbar curvature of the vertebral column, which produces a swayback condition.