Human bones are fairly strong formations, but even they can break. When exposed to some pressure on the bone, it begins to bend, exhibiting elastic properties. If the pressure is too large and occurs in a short period of time, then it can break. How the bones are fused after a fracture is considered in the article.
Osteogenesis and reabsorption
Before considering the question of how the bones grow together after a fracture, it is necessary to talk about such phenomena that occur in the body of each person, such as osteogenesis or the generation of new bone, and reabsorption or destruction of the old bone.
The processes of generation and destruction of bone tissue occur continuously in the human body throughout his life. According to rough estimates, about 5-15% of the bone tissue of the human skeleton is renewed every year, and over 10 years all skeleton bones undergo a complete renewal. The rate of osteogenesis and reabsorption depends on the individual characteristics of the organism, but also on its age. In the process of aging, both processes slow down, and their effectiveness decreases, therefore, when a person is in advanced age, he has various pathologies associated with bones.
The process of osteogenesis occurs with the help of special cells that are responsible for creating, restoring and maintaining a healthy bone, these cells are called osteoblasts. As mentioned above, osteoblasts perform bone renewal constantly, regardless of whether it is damaged or not.
Since any process of regeneration and creation of a new bone requires the destruction of old tissues that have lost their functions, osteogenesis is always accompanied by reabsorption of the old bone. This process is also carried out using appropriate cells called osteoclasts.
It is important to understand that the ongoing processes of destruction and bone formation do not mean that at some point in time a person’s skeleton is weakened and the bones are fragile, the body always maintains the musculoskeletal system in optimal condition, while it gradually replaces the old bone fabrics to a new one.
What is a bone fracture?
Before proceeding to the disclosure of the question of how the bones are fused after a fracture, it is necessary to define the fracture itself. In humans, the bone is a very strong and strong connective tissue, but with small deformations it can break. By a bone fracture is understood a violation of its integrity.
Fracture is a mechanical process that activates some biological reactions, such as bone resorption and the formation of edema, depending on the presence of blood vessels at the fracture site. Immediately, we note that if there is little muscle tissue and a small number of blood vessels at the fracture site, then the bone fuses poorly and slowly after the fracture .
Fracture can have a different nature. If we draw an analogy with a fracture of wooden rods, then we can say that the green twig and dry stick have a different type of kinks. The following fracture types are currently distinguished:
- A complete fracture, that is, a bone breaks into two separate parts.
- A partial fracture or a fracture of the "green twig", while the bone does not experience integrity violation over its entire cross section.
- An individual fracture, that is, a fracture occurs in only one place.
- A comminuted fracture, the bone breaks in several places and the fracture sites remain sharp.
- An arcuate fracture is a situation that only happens in children, and in which the bone is bent in half but not broken.
- Open fracture - part of the bone breaks the soft connective tissues of the body (muscles, skin) and protrudes to the surface.
Recovery phases
How do bones grow together after a fracture? This process is quite lengthy and complicated. After a violation of the holistic structure of any bone has occurred, the body starts a series of reactions that seek to restore the resulting injury in the shortest possible time. The process of restoring broken bones is usually divided into three phases:
- inflammatory and proliferative phase;
- the formation of primary connective tissue callus in the fracture area;
- restoration or reconstruction of the bone.
These phases go one after another. The following describes in detail what happens in the body and in the bone itself during each of these recovery phases.
Inflammatory and proliferative phase
The answer to the question of how the bones are fused after a fracture should begin with the fracture process itself. If the amount of mechanical energy transmitted to the bone does not exceed a certain limit value, then all this energy is absorbed by the bone and the soft tissues surrounding it, and the integrity of the bone is not violated. If the mechanical energy is large, then it is not completely absorbed by the bone and leads to its destruction, which entails local bleeding and necrosis of bone cells and soft tissues in the destruction zone. At the time of fracture, the following processes occur:
- Migration of cells to the fracture site due to a number of chemical processes that start at the time of the fracture.
- Acceleration of cell division at the fracture site.
- The accumulation of fluid in the intercellular space and increased permeability of blood vessels, which leads to edema in the area of bone damage.
- The launch of inflammatory processes, the signs of which are redness, pain, an increase in volume, fever, failure to perform functions and deformation in the fracture area. The goal of all inflammatory processes is to free the fracture zone from dead cells and tissues in order to facilitate the subsequent restoration of bone integrity. In the period from 4 to 21 days in the fracture zone there is a constant increase in the number of blood vessels that are responsible for feeding the damaged area and the removal of decay products and dead cells. After 3 weeks after the fracture, the process of increasing the number of vessels in the specified zone slows down.
If you move a broken bone during the inflammatory and proliferative phases, you can hear the sounds of squeaking and friction between the broken areas.
Primary connective tissue formation phase
We continue to open the question of how many bones are fused after a fracture. After the first phase, the primary bone marrow formation phase begins in the fracture zone. This happens between the 2nd and 3rd week after the accident. This phase is characterized by accelerated proliferation of cells of the outer lining of the bone and surrounding soft tissues and blood vessels. The activity of the following groups of cells is activated in this phase:
- Osteoblasts that form new bone tissue.
- Osteoclasts responsible for the destruction of dead bone.
- Chondroblasts are cells that create cartilage.
At the beginning of the phase, the callus is soft. The cells of the outer layers of the bone begin to quickly divide and grow together in such a way that they completely envelop the bone callus. As a result of this process, fragments of a broken bone turn out to be rigidly connected to each other and can no longer move independently of each other.
After this, the process of bone marrow mineralization starts, which is carried out by depositing calcium hydroxyapatite crystals in it and the formation of osteoid tissue. At this time, the formation of primitive bone tissue, which has a fiber-lamellar structure. This structure is able to completely stabilize the fracture zone, however, it is not able to withstand external loads. As the mineralization process develops, the hardness and strength of young bone tissue increases. As soon as all the above-mentioned signs of inflammatory processes disappear in the fracture zone, it can be considered that mineralization has completed completely, and the young bone can already withstand some small loads.
Bone Restoration Phase
How long do bones heal after a fracture? The answer to this question is the duration of the last phase of bone restoration. Complete restoration of the integrity of bone tissue can last several months or even years.
What factors influence the speed of the bone restoration phase? There are several of these factors, the main ones are listed below:
- cell factor;
- blood vessel system formation;
- biochemical properties of the body (hormones, vitamins);
- local biochemical factors (ability to grow bone tissue);
- mechanical factors.
So, if there are no blood vessels in the area of bone disturbance, then it will never be restored, since restoration is impossible without oxygen and nutrients, for the transport of which the blood vessels are responsible. If the bone does not grow together after the fracture, what to do, one of the solutions will be inoculation into the fracture zone of the part of the bone, which has enough blood vessels.
Do not forget about the positive effect of certain hormones (parathyroid hormone, growth hormone, estrogen and others), which accelerate the healing process. Vitamins C and D have a similar function.
Offset fracture
The above information refers to the restoration of parts of the bone when they are located correctly relative to each other. With fractures, one part of the damaged bone is often displaced relative to the other. How does a bone grow together after a fracture with a displacement? The recovery process is similar to the phases described above, only before this fusion begins, doctors try to bring the broken parts of the bone to the correct relative position.
How many bones are fused after a fracture with a displacement? As a rule, this time is longer than the recovery period after a fracture without displacement, since displacement causes damage to a larger volume of tissue.
Pseudoarthrosis in the process of bone restoration
After the integrity of the bone has been violated, the body immediately enters into the work of restoring it. However, for one reason or another, this process can be slowed down, parts of the bone remain motile for a long time, and each microdisplacement in them is accompanied by severe and acute pain. At this time, the patient wonders why the bone does not grow together after a fracture. Most often this is due to the appearance of pseudoarthrosis.
The essence of pseudoarthrosis is as follows: after a fracture, after 1-2 weeks, the cells of the outer surface of the halves of the bone begin to connect with each other and should surround the bone callus located in the center of the fracture. But this corn does not form, since the ends of the parts of the bone are covered with a membrane that prevents them from joining over the entire cross-sectional area. The result is a structure that is similar to a joint, and which is also mobile, because the outer fused layers of the bone cannot completely stabilize the fracture zone.
The causes of pseudoarthrosis in the process of bone restoration are as follows:
- Increased mobility in the fracture zone. This occurs when the patient behaves inaccurately, or when the gypsum is not applied correctly and does not stabilize the completely damaged area. In this case, the bone after the fracture also fuses incorrectly.
- Insufficient number of blood vessels in the fracture zone. This leads to a significant slowdown in the formation of bone marrow.
- Genetic and biological factors. An individual feature of the body of a particular person does not allow him to quickly restore damaged bone tissue.
Pseudoarthrosis is a very serious problem that explains why the bone does not grow together after a fracture. What to do? It is only solved surgically, when you have to expose the fracture area again, clean the ends of the bone parts from the membrane that has arisen, join them and create conditions for a new recovery process.
Slowing Factors
How long does a bone grow together after a fracture? The answer to this question cannot be unambiguous, since there are a number of factors that slow down the recovery process:
- High doses and prolonged use of certain medications, such as corticosteroids.
- Systemic factors: lack of calcium or a malfunction of the hormonal background in the body, the patient’s large age.
- The size and location of the fracture of the bone. There are places where fractures heal very slowly, especially if they are open.
- The amount of dead tissue. How long do the bones heal after the fracture if sufficiently strong injuries are received in its area? Several months, subject to all procedures aimed at accelerating this recovery. The fact is that with severe fractures in their area, the amount of dead bone tissue is significant, which leads to a decrease in the restoration ability of the bone.
- Mobility and displacements in a broken bone, which not only slow down the process of restoring bone integrity, but also increase the risk of incomplete recovery.
- Infections in the fracture zone. They can appear with open fractures or during careless surgical operations. An infected fracture will never heal.
- Weakened bone, for example, due to bone metastasis or osteoporosis.
As can be seen from the list, the process of bone fusion leads to many difficulties. If the patient observes all safety precautions, and he does not have any of the factors mentioned above that inhibit bone growth, then answering the question of how quickly the bones heal after a fracture, we can say the numbers are 1-2 months in young people and up to six months or more in the elderly person.
How to speed up the recovery process?
When for one reason or another there is a slowdown in the rate of bone fusion, it is necessary to find out all the factors that cause this slowdown, and eliminate them. Another good rule for quick recovery is to increase the length of time the fracture is stationary. In some cases, you can resort to the help of mechanical and electrical stimulants.
The essence of mechanical stimulants is the application in various ways of additional external pressure to the fracture zone in order to increase the contact density between the parts of the broken bone. As for electrical stimulants, some studies have shown that passing electric current pulses through a fracture stimulates bone cell division, thereby accelerating the process of fusion. Also, the effect of an electromagnetic field on a fracture modifies the bioelectric field of the soft tissues surrounding the damaged area, which favors the process of restoring bone integrity.
Doctors advice
The answer has already been given to the question of how many days the bones heal after the fracture, from which it is clear that this process takes several months. However, it is possible to reduce the recovery period for a patient who is wearing plaster, if elementary rules are followed. The following actions are doctors recommendations:
- Perform movements within the cast. These movements should be performed smoothly without significant effort. Note that this should be done only when the pain disappears, which approximately occurs 2 weeks after the fracture.
- To load a limb with gypsum with small weights. This should be done carefully, controlling the amount of load.
- If the patient has a crack in the bone and a splint is placed in order to immobilize the injured limb. Then from time to time it is recommended to remove this tire, take a contrast shower for this limb, make smooth movements, then put the tire back in place.
All of these recommendations are quite simple, however, they can speed up blood circulation in the area of damage, which significantly reduces the recovery time.