Bone Fractures are are injuries of bone tissue, which compromise their ability to support the body. A bone fracture can occur in several situations, like a car accident, an assault, a fall in the bathroom or from a height, due to a pre-existing bone disease, like osteoporosis, rickets, and so on. The symptoms of bone fracture may vary depending on the types of bone fractures, their location, as well as their severity. However, every fracture results more or less from an unbalanced force, which overcomes the strength of the bone.
Bone Fracture Physiology
Bone tissue is structurally very hard, but when it is subjected to forces higher than its capacity it responds in two ways. When the forces are applied in one instant, like a sudden fall, it results in a bone fracture. But if it is applied slowly over a period of time, it results in remodeling of the bone to a shape that balances the forces e.g. bowing of legs in rickets. Thus, the bone has a dynamic nature and adjusts to the changing loads of weight bearing and physical stress. This ability of bones is due to the constant erosion of bone by osteoclasts and deposition of new bone by osteoblasts (Picture 1).
Picture 1: Bone Fracture Physiology
A delicate balance between these cells is responsible for thickening or thinning of bones, depending on the activity performed by a person. Hence, a manual laborer has a much sturdy skeleton than a sedentary working clerk in an office. Thus, after a bone fracture, the bones have an intrinsic ability to heal themselves due to the deposition of bone by osteoblasts. It also indicates that pressure acting on a particular bone tends to increase the thickness of the bone over time and helps better healing of bone fractures.
Types of Bone Fractures
There are several ways to classify a bone fracture, which satisfies specific motives. Each of the bone fracture types, gives us certain information about the fracture, which influences the type of treatment given to a person. Hence, it is very important to understand which of the several types of bone fractures, does one actually have.
Displaced Bone Fracture is when the broken ends of a fracture move away from each other and there is a significant gap between them, when seen on an x-ray. The significant gap is different for different types of bone fractures, for example, a gap of 3-4 mm may be insignificant in a humerus bone fracture, but can be significant in a finger phalanx fracture.
Undisplaced Bone Fracture or Hairline Fracture is when a bone develops a crack or breaks through and through, but the broken ends remain in place, without any displacement or gap. These bone fractures, are best treated with a simple fiberglass or plaster cast and generally do not require surgical treatment.
Pathological Bone Fracture is when a bone has been weakened by a disease, like cancer, osteoporosis, etc., and develops a fracture. Such bone fractures do not require a lot of force and are possible after trivial falls or even without any traumatic incident.
Compound Bone Fracture is when the broken bones pierce the skin and create an external wound. These bone fractures are associated with higher rates of infection, due to exposure of the bone to the surrounding dirt and also cause profuse bleeding from the wound.
Long Bone Fracture Types
Long bones, like femur (thigh bone), tibia & fibula (leg bones), humerus (arm bone), radius & ulna (forearm bones) or clavicle (collar bone), have particular types of bone fractures, where the edges of broken bones have a characteristic shape. This not only influences the outcome of the bone fracture, but also dictates the bone fracture repair method which can be used for treatment.
Spiral Fracture is when a twisting force is applied to a bone, resulting in long curvy edges of the broken bones, like a spiral. Due to the zig-zag nature of the fractured ends of bone, it is slightly easier to treat a spiral fracture of long bones.
Comminuted Fracture is when a bone breaks into several small pieces and is the result of high velocity injuries, like car accidents, or falls from a height. Such bone fractures generally are very difficult to treat, and result in a deformity of the injured part even after treatment.
Bone Fracture Symptoms
Symptoms of bone fractures can range from a mild bone pain to severe bruising, bleeding, and inability to move the part of the body.
- Pain – is due to pain signals from the injured bone in response to pressure on the bone fracture.
- Swelling – is due to injury to local blood vessels and also the action of the cells of immune system of the body.
- Inability to walk – is after an injury to the weight bearing bones of the body, mainly the bones of the leg or thigh.
- Instability – is when the bone fracture is near a joint and causes the joint to dislocate.
- Inability to breath – is in the case of rib fractures, where a sharp stabbing pain can be felt at each breath.
Bone Fracture Treatment
Treatment for bone fractures consist of immobilization of the injured part in most of the cases. This is accomplished with the help of a cast moulded on to the injured part. Plaster of Paris (cheap) or Fiberglass (expensive) may be used for the cast depending on the requirement and availability. Several splints are also available for the same purpose, are more comfortable than a cast and provide similar results. Generally, such an immobilization has to be retained for 4-6 weeks, to allow sufficient time for bone fracture healing.
Prior to immobilization, it is essential to ensure that the displacements between the fractured ends of bones are reversed and the bones are brought into their natural anatomical alignment. This procedure is called fracture reduction and involves manipulation of the ends of the broken bones. Reduction can be accomplished under x-ray guidance with the help of a C-Arm. Due to the painful nature of fracture reduction procedure, it is essential to give the patient adequate analgesic cover or iv sedation. By reducing bone pain a person is able to relax the muscles of the injured part, which helps greatly in fracture reduction.
Bone Fracture Surgery
Surgical treatment for bone fractures is reserved for displaced fractures and primary management of compound fractures. Displaced bone fractures have a higher propensity of developing non-union or mal-union. Hence, surgery has to be performed, preferably within a week after injury to bring the broken ends of the bones together. The broken edges are approximated as neatly as possible and secured in that position with the help of orthopedic screws and plates. This provides temporary support, which is sufficient to maintain the position of the bones, until bone fracture healing.