Introduction to fracture
Bones form the skeleton of the body and allow the body to be supported against gravity and to move and function in the world. Bones also protect some body parts, and the bone marrow is the production center for blood products.
Bone is not a stagnant organ. It is the body's reservoir of calcium and is always undergoing change under the influence of hormones. Parathyroid hormone increases blood calcium levels by leeching calcium from bone, while calcitonin has the opposite effect, allowing bone to accept calcium from the blood.
What causes a fracture?
When outside forces are applied to bone it has the potential to fail. Fractures occur when bone cannot withstand those outside forces. Fracture, break, or crack all mean the same thing. One term is not better or worse than another. The integrity of the bone has been lost and the bone structure fails.
Broken bones hurt for a variety of reasons including:
- The nerve endings that surround bones contain pain fibers and and these fibers become irritated when the bone is broken or bruised.
- Broken bones bleed, and the blood and associated swelling (edema) causes pain.
- Muscles that surround the injured area may go into spasm when they try to hold the broken bone fragments in place, and these spasms cause further pain.
Often a fracture is easy to detect because there is obvious deformity. However, at times it is not easily diagnosed. It is important for the physician to take a history of the injury to decide what potential problems might exist. Moreover, fractures don't always occur in isolation, and there may be associated injuries that need to be addressed.
Fractures can occur because of direct blows, twisting injuries, or falls. The type of forces on the bone may determine what type of injury that occurs. Descriptions of fractures can be confusing. They are based on:
- where in the bone the break has occurred,
- how the bone fragments are aligned, and
- whether any complications exist.
The first step in describing a fracture is whether it is open or closed. If the skin over the break is disrupted, then an open fracture exists. The skin can be cut, torn, or abraded (scraped), but if the skin's integrity is damaged, the potential for an infection to get into the bone exists. Since the fracture site in the bone communicates with the outside world, these injuries need to be cleaned out aggressively and many times require anesthesia in the operating room to do the job effectively.
Next, there needs to be a description of the fracture line. Does the fracture line go across the bone (transverse), at an angle (oblique) or does it spiral? Is the fracture in two pieces or is it comminuted, in multiple pieces?
What are common types of fractures?
Stress fracture
A stress fracture is an overuse injury. Because of repeated micro-trauma, the bone can fail to absorb the shock that is being put upon it and become weakened. Most often it is seen in the lower leg, the shin bone (tibia), or foot. Athletes are at risk the most, because they have repeated footfalls on hard surfaces. Tennis players, basketball players, jumpers, and gymnasts are typically at risk. A March fracture is the name given to a stress fracture of the metatarsal or long bones of the foot. (It is named because it often occurs in soldiers who are required to march long distances.)
Diagnosis is made by history and physical exam, though on occasion a bone scan may be done to confirm the diagnosis.
Treatment is conservative, rest, ice, and anti-inflammatory medication like ibuprofen. These fractures can take six to eight weeks to heal (as long as the fracture can be seen on x-ray). Trying to return too quickly can cause re-injury, and may also allow the stress fracture to extend through the entire bone.
Shin splints may have very similar symptoms as a stress fracture of the tibia but they are due to inflammation of the lining of the bone, called the periosteum. Shin splints are caused by overuse, especially in runners, walkers, dancers, including those who do aerobics. Muscles that run through the periosteum and the bone itself may also become inflamed.
Treatment is similar to a stress fracture and physical therapy can be helpful.
Compression fracture
As people age, there is a potential for the bones to develop osteoporosis, a condition where bones lose their calcium content. This makes bone more susceptible to breaking. One such type of injury is a compression fracture to the spine, most often the thoracic or lumbar spine. Since we are an upright animal, if the bones of the back are weaker than the force of gravity these bones can crumple. Pain is the major complaint, especially with movement.
Compression injuries of the back may or may not be associated with nerve or spinal cord injury. An x-ray of the back can reveal the bone injury, however, sometimes a CT scan or MRI will be used to insure that no damage is done to the spinal cord.
Treatment includes pain medication and often a back brace. Some compression fractures can also be treated with vertebroplasty. Vertebroplasty involves inserting a glue-like material into the center of the collapsed spinal vertebra in order to stabilize and strengthen the crushed bone. The glue (methylmethacrylate) is inserted with a needle and syringe through anesthetized skin into the midportion of the vertebra under the guidance of specialized x-ray equipment. Once inserted, the glue soon hardens, forming a cast-like structure with the locally broken bone.
What is the treatment of a fracture?
Initial treatment for fractures of the arms, legs, hands and feet in the field include splinting the extremity in the position it is found, elevation and ice. Immobilization will be very helpful with initial pain control. For injuries of the neck and back, many times, first responders or paramedics may choose to place the injured person on a long board and in a neck collar to protect the spinal cord from potential injury.
Once the fracture has been diagnosed, the initial treatment for most limb fractures is a splint. Padded pieces of plaster or fiberglass are placed over the injured limb and wrapped with gauze and an elastic wrap to immobilize the break. The joints above and below the injury are immobilized to prevent movement at the fracture site. This initial splint does not go completely around the limb. After a few days, the splint is removed and replaced by a circumferential cast. Circumferential casting does not occur initially because fractures swell (edema). This swelling would cause a build up of pressure under the cast, yielding increased pain and the potential for damage to the tissues under the cast.
Surgery
Surgery on fractures are very much dependent on what bone is broken, where it is broken, and whether the orthopedic surgeon believes that the break is at risk (for staying where it is) once the bone fragments have been aligned. If the surgeon is concerned that the bones will heal improperly, an operation will be needed. Sometimes bones that appear to be aligned normally are splinted, and at a recheck appointment, are found to be unstable and require surgery.
Surgery can include closed reduction and casting, where under anesthesia, the bones are manipulated so that alignment is restored and a cast is placed to hold the bones in that alignment. Sometimes, the bones are broken in such a way that they need to have metal hardware inserted to hold them in place. Open reduction means that, in the operating room, the skin is cut open and pins, plates, or rods are inserted into the bone to hold it in place until healing occurs. Depending on the fracture, some of these pieces of metal are permanent (never removed), and some are temporary until the healing of the bone is complete and surgically removed at a later time.
