HOW DOES A BROKEN BONE HEAL?
Tid Bits of Info
- Human bones will heal in approximately 6-8 weeks.
- The thigh bone, Femur, is the strongest bone in the body and can withstand forces up to approximately 2500 lbs.
- The lateral ankle bone, Fibula, is the most commonly fractured bone.
- Bone remodels throughout life, osteoclasts break down old bone and osteoblasts produce new bone cells.
- Seek the advice and treatment of a Physical Therapist to restore your function after a fractured bone heals.
Bones break. One person falls to the ground. Another gets hit so hard by a baseball that the wrist bone breaks. Bones break but they also heal. Did you ever wonder how a bone heals itself? There are several stages that take place during the healing process and if all goes well the bone usually heals itself within 6-8 weeks.
Human bone is one of the hardest structures in the human body. The rigidity of the bone enables it to withstand tremendous stress and strains of many kinds and from many directions. Unlike most hard objects such as glass and stone, healthy bone has an elastic component to its characteristics. This elasticity, due to collagen, enables the bone to deform and slightly change shape without breaking.
Withstanding force is a property resulting from the bone’s composite of organic and inorganic material. The bone is constantly remodeling itself, and it will react positively or negatively to the mechanical load that is placed upon it. When the load is heavy the bone will respond by producing more bone and when there is disuse the bone will lose bone material.
The health status of human bones and their ability to withstand stress and strain is reliant upon several factors. Age, gender, part of the body, mineral/water content and disease such as osteoporosis can affect the health of the bone. The health of the bone prior to any fracture will determine how long it takes to heal if it is broken.
When someone’s bone is subjected to enough force it will break or fracture. In a healthy individual (with no health conditions that will slow down the healing time) the bone should heal completely in roughly 8 weeks.
The healing process of a broken bone can be separated into three stages. The inflammatory stage, repair stage and remodeling stage make up the entire process and once complete the bone has been restored to its original physical and mechanical status.
The inflammatory stage begins immediately following the occurrence of a fracture. A hematoma forms within hours to a few days and the inflammatory cells infiltrate the bone. This enables new tissue to develop that prepares the bone to produce new bone cells. Vascular tissue is developed and enables the new bone growth to be “nourished” with blood flow. Necessary nutrients and oxygen are present in the area of new bone.
The second stage, repair, is the stage that the first new bone cells are present. The vascular tissue begins to have a collagen matrix develop with in it and a soft callus is formed around the fracture. The callus is very weak and poorly formed for the first 4 weeks.
The last stage, remodeling, is the stage when the bone completely heals and is restored to its original properties. The bone will continue to remodel itself for its lifetime, providing it remains healthy. Mechanical stresses that are placed upon it will initiate more bone growth. Immobility is needed in the beginning to allow the callus to form, but a transition out of the splint or cast is needed to enable the final remodeling stage to be completed.
The fracture of a long bone usually requires a period of immobility. The immobility can create a host of orthopeadic problems such as joint stiffness, muscle atrophy, cartilage softening and surrounding bone osteopenia/osteoporosis. In many cases the immobility creates more issues than the original fracture site. The conditions that can occur with prolonged immobility have lead orthopaedic doctors to develop protocols and treatment techniques that enable a fracture site to be moved more readily than in the past. It is rare for someone to be in a completely immobilized state for more that 3-4 weeks.
Your orthopaedic doctor will have you attend Physical Therapy when you are capable of moving the fracture site without fear of re-injuring the healing bone. The Physical Therapist will help you reduce swelling and pain, restore motion and begin the long process of developing enough strength and neuromuscular control to regain full functional use of the injured body part.
Human bones are capable of withstanding a tremendous amount of force and can adapt its shape to handle it, but there is literally a “breaking point”. If the bone fractures it will heal. The healing time is dependent upon the overall health of the individual, but in the “healthy” population the bone should return to its pre-fracture status within 8 weeks. A thorough rehabilitation program that is supervised by a Physical Therapist will be needed to restore the full functional capabilities of the involved body parts.