Broken Bones and Injuries

broken bone

If more pressure is put on a bone than it can stand, it will split or break. A break of any size is called a fracture. If the broken bone punctures the skin, it is called an open fracture or compound fracture.

A stress fracture is a hairline crack in the bone that develops because of repeated or prolonged forces against the bone. Alternative Names Bone - broken; Fracture; Stress fracture

Considerations

It is hard to tell a dislocated bone from a broken bone. However, both are emergency situations, and the basic first aid steps are the same.

Anatomy

Bone consists of living cells widely scattered within a nonliving material called the matrix. The matrix is formed by osteoblasts, cells that are constantly renewed in the bone. Osteoblasts make and secrete the protein collagen, which makes bones elastic so that they can give under the stresses generated by walking, lifting, and other activities. Osteoblasts also secrete mineral salts formed from calcium and phosphorus, which impart hardness so that bones do not break easily. If more bone is needed, new osteoblasts carry out the task of building it. As bone tissue matures, osteoblasts transform into osteocytes, mature bone cells that carry out daily cellular activities.

healthy bones are strong and light

There are two main types of bone. Compact bone, which makes up most of the bone of arms and legs, is very dense and hard on the outside. The structural units of compact bone are osteons, elongated cylinders that act as weight-bearing pillars, able to withstand any mechanical stress placed on the bone. The center of each osteon contains a hollow canal that acts as a central passageway for blood vessels and nerves.

In some bones, internal to the compact bone is spongy bone, also known as cancellous bone, composed of a honeycomb network of bones called trabeculae that act as supporting beams. Spongy bone is designed to bear stress from several directions, such as that exerted on the pelvis in bending or stretching. The spaces between the trabeculae are filled with red bone marrow containing the blood vessels that nourish spongy bone. Spongy bone is found in bones of the pelvis, ribs, breastbone, vertebrae, skull, and at the ends of the arm and leg bones.

Surrounding both compact and spongy bone is a thin membrane, the periosteum. The outer layer of this membrane contains nerves and blood vessels that branch and travel into the bone. The inner layer of the periosteum consists mainly of osteoblasts.

The point where two or more bones come together is called a joint, or articulation. Different kinds of joints enable different ranges of motion. Some joints barely move, such as those between the interlocking bones of the skull. Other bones, held together by tough connective tissues called ligaments, form joints such as the hinge joint in the elbow, which permits movement in only one direction. The pivot joint between the first and second vertebrae allows the head to turn from side to side.

Intimately associated with bone is another type of connective tissue called cartilage. Cartilage is softer, more elastic, and more compressible than bone. It is found in body parts that require both stiffness and flexibility, such as the ends of bones, the tip of the nose, and the outer part of the ear.

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Cause

Figure shows living and nonliving components of a bone

The following are common causes of broken bones:

  • Fall from a height
  • Motor vehicle accidents
  • Direct blow
  • Child abuse
  • Repetitive forces, such as those caused by running, can cause stress fractures of the foot, ankle, tibia, or hip
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Symptoms

Often you can tell there is a broken bone just by sight. Here are the common symptoms to look for if you suspect a bone is broken.

  • A visibly out-of-place or misshapen limb or joint
  • Swelling, bruising, or bleeding
  • Intense pain
  • Numbness and tingling
  • Broken skin with bone protruding
  • Limited mobility or inability to move a limb
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Diagnosis

Magnetic resonance image (MRI) or X-rays can be used to detect broken bones

The most common diagnostic method to see if a bone is broken is the X-ray. More recently however, if the X-ray is not sufficient, for example if the fracture is too small to be seen by a simple X-ray, then Magnetic resonance imaging (MRI)will be used as well

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Treatment

Medical issues to consider

Treatment to set a broken bone depends on the location and severity of the injury. Some of the different types of fracture include:

  • Closed (simple) fracture - the skin remains intact and there is little damage to surrounding tissue.
  • Open (compound) fracture - the broken bone protrudes through the skin or there is a wound that leads to the fracture site.
  • Complicated fracture - in addition to the fracture, there is injury to the surrounding structures. There may be damage to the veins, arteries or nerves and there may also be injury to the lining of the bone (the periosteum).

Operation procedure

Plaster of Paris is one of the most common methods used to immobilise a limb. This cast is made from a preparation of gypsum that sets hard when water is added. Operation procedures depend on the location and severity of the fracture, for example:

  • Closed or simple fractures - the two ends of the broken bone are lined up and held in place. The limb is thoroughly bandaged then the wet plaster is applied. Sometimes, once the plaster is dry, the cast is split into two and the two halves are then re-bandaged on the outside. This allows for any swelling that may occur.
  • Open or compound fractures - these have to be thoroughly cleansed in the operating room to remove debris prior to being set because a broken bone exposed to the open air is at increased risk of infection.
  • Long bones - long bones, like the bone of the thigh (femur), are difficult to keep aligned and, in adults, are generally treated by internal nailing. Children may need traction for a couple of days prior to setting in a cast. Once the two ends of bone start to show signs of healing, the leg and hip joint are immobilised in plaster of Paris. In other cases, pins are inserted above and below the fracture and secured to an external frame or ‘fixator’ under a general anaesthetic.

Immediately after the operation

Your doctor checks that you have full feeling in the limb. For example, if you have a broken arm in plaster, you are asked to wiggle your fingers. Your limb is also checked for tingling, pallor or coolness. The injured part is immobilised as much as possible in the first few days (with the aids of splints, if necessary) in order to reduce pain and displacement of the fracture.

The nursing staff will offer you adequate pain relief medication. They will determine the difference between the pain of your fracture and any pain that could be caused by the splint, traction, plaster cast, poor alignment of the limb or swelling of the limb following the fracture.

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Prevention

To grow, develop and maintain healthy bones, it is important that you have enough calcium in your diet. Good sources of calcium include milk, cheese and yoghurt. Vitamin D helps the body to absorb calcium - you can find it in margarine and oily fish.

Because of the way bones are made, they get stronger and denser with regular exercise. It is particularly important that older people remain active, as this will help to reduce their risk of fractures.

The female hormone oestrogen regulates the use of calcium in a woman's body. After the menopause, women produce far less oestrogen, making calcium regulation more difficult. This means that it is particularly important that women make their bones as strong as possible before the menopause.