Bone is a highly dynamic tissue of the body. It is quite similar to skin, for the fact that its outer layers are constantly being broken down as new layers of tissue are added from the inner side. This constant renewal of layers makes bone fracture healing process automatic, and it does not require any treatment. However, bone fractures (broken bones) are frequently associated with loss of normal alignment of the bone and instability at the fracture site. If this is not corrected, it leads to complications like nonunion and malunion.
Fracture Healing Process
A fracture or break in a bone causes bleeding at the fracture site. This blood collects around the fracture forming a spindle shaped clot. The immune cells present inside this blood begin the repair process to bridge the gap between the ends of the broken bones. They form a scaffolding of collagen fibers, which is reorganized by the precursor bone cells from the ends of the bone to transform it into premature bone called osteoid. This osteoid is impregnated with calcium to form a loose supportive bone tissue called the callus. The callus is then subjected to remodeling during the normal renewal of bone tissue layers and is transformed into the normal hard bone tissue.
Fracture Healing Principles
The fracture healing process begins right from the time of injury and proceeds at a constant rate, with slight variations depending on age of patient and location of injury. Thus, there are high chances of a bone fracture uniting in a deformed position if the misalignment of bones caused by the injury is not corrected before bone fracture healing.
Picture 1: Malunion of wrist fracture
(Source: Wikimedia Commons)
Malunion (Picture 1) is bone fracture healing in a deformed position and may be functionally or cosmetically unacceptable. Also the gap between the ends of broken bones after injury should be less to ensure bone fracture healing. Failure of broken bones to unite is called nonunion (Picture 2) of fractures, which are highly resistant to any form of treatment.
Picture 2: Nonunion of Leg bones
(Source: Wikimedia Commons)
Bone fracture leads to loss of stability, since the main supporting structure is damaged. The pull of the muscles as well as the effect of gravity may act in 2 ways. It may either keep the ends of broken bones together and support the fracture, or it may pull the ends away from each other and prevent any corrective attempts by the orthopedic doctor. Thus, in the former case, there is no need for any special treatment and the bones can unite due to normal bone fracture healing. However, in the latter case, an orthopedic surgery may be required, which uses orthopedic bone screws or lag screw fixation to keep the ends of broken bones together.
Bone Fracture Healing at different Ages
Children have the highest potential for healing of broken bones. Even if the ends of broken bones are away from each other they tend to unite. Even if the broken bones unite with a deformity, it corrects over a period of few years along with the normal growth of the child.
Elderly people are prone to develop several complications like non-union, delayed union, and so on, after a bone fracture. Hence, many times, it is prudent to fix a bone with surgical methods in them to ensure they get enough support during their prolonged process of bone fracture healing.
Fracture Healing Recovery time
The time required for bone fracture healing process is highly variable depending on the location of the fracture as well as age of the patient. The average fracture healing time for some of the common fractures are
- Wrist fracture healing time – 3 to 4 weeks
- Fibula fracture healing time – 4 t0 6 weeks
- Tibia fracture healing time – 4 to 6 weeks
- Ankle fracture healing time – 5 to 8 weeks
- Rib fracture healing time – 4 to 5 weeks
- Jones fracture healing time – 3 to 5 weeks
- Foot fracture healing time – 3 to 4 weeks
- Metatarsal fracture healing time – 5 to 6 weeks
- Metacarpal fracture healing time – 3 to 4 weeks
- Hairline fracture healing time – 2 to 4 weeks
- Finger fracture healing time – 2 to 3 weeks
- Toe fracture healing time – 2 to 4 weeks
These average healing times are for the fractures that have been stabilized with some or the other form of fracture treatment, be it a cast, splint, or surgery. Several factors, like nutrition and severity of the fracture also lead to variable fracture healing time in different people having the same fracture.
In children most of the fractures heal within 3-4 weeks, whereas, in adults they take 4-6 weeks. Elderly people have a more delayed course of fracture healing and it may take up to 8 weeks. Fractures present in areas of high blood supply, like spine, wrist, and so on, heal earlier than that in areas of low blood supply, like scaphoid (wrist bone), tibia (leg bone), and so on. Hence, surgical treatment of such fractures is a must.