How are Children’s Bones different from Adult’s Bones?

A bone is a rigid organ that plays an essential part in the human body. Bones protect different organs of the body, creates white and red blood cells, store minerals, give structure and support, and enable mobility. 

Bones come in several sizes and shapes with an elaborate external and internal structure. They are lightweight yet rigid and strong and serve various functions.

Newborn babies have around 300 bones and those bones grow and change shape every day.

Adults have around 206 bones, which make up about 15 per cent of their body weight.

The reason why babies have more bones than adults is that bones are made up of living tissue and calcium. Bones develop and discard throughout your life.

Anatomic bone differences: children vs adults

Bones in children and adults have anatomical differences. A fully-developed adult bone has two regions called the diaphysisandmetaphysic. A developing child’s bone has four areas known as the diaphysis, metaphysis, epiphysis,and physis.

The physis is the growth plate, and the epiphysis is the rounded portion at the end of the bone. The epiphysis begins out as cartilage and contributes to the joint. Eventually, the epiphysis becomes hard and attaches itself to the bone as the child grows. 

The osteoid density of an infant’s bone is less than that of grown-ups. The juvenile bone holds more Haversian canals. Haversian canals are minute tubes that form a network in the bone and have blood vessels. It makes the bone more flexible than an adult’s bone. Although children and adults have similar risks for injury, the developing bone can break in a different way than a developed bone.

Fractures in children’s bones

The bone structure of a child and an adult are different as well. The differences are significant for accurate evaluation and treatment of fractures. 

A child’s bones heal quicker than an adult’s bone. Adult’s bones are thicker, stronger, and more active dense fibrous membrane (periosteum) covers the surface of their bones. 

The periosteum contains blood vessels that provide nutrition and oxygen to the bone cells. The thicker and stronger periosteum in children makes a better provision of nutrients and oxygen to the bones. This helps in the remodeling of the fractured bones as well.

The periosteum in children causes a rapid union of fractured bones and an enhanced potential for remodelling.

A child’s fractures not only heal swiftly but are significantly decreased due to the strength and thickness of a child’s periosteum. This thickness has its demerits.

When there is a minute displacement in the periosteum, the strength and thickness make a fracture in the periosteum challenging to diagnose. 

Growth Plate Fractures

Growth plate fractures happen in the area of cartilage placed at the ends of the bone (physis). It eventually hardens as the bone grows.

As growth plates determine the future length of the bone, fractures in this area require immediate treatment. Without treatment, it may cause stunted or deformed growth in the child. 15 to 30 per cent of childhood fractures take place in the growth plates. However, treating this injury is relatively simple; it rarely leads to any severe problems.

Flexibility (buckle injury)

Children’s bones can bend before they actually break. An adult bone is rigid and strong, only an immense force can cause a fracture, but in the end, it will snap. The flexibility in a child’s bone means it will bend a couple of times before it eventually breaks, leading to a different type of fracture.

Buckle fractures are common in the forearm. Still, it can happen to any bone. 40 per cent of childhood fractures take place in the forearm. It is due to the makeup of the arm and how the child uses it. We use our arms to brace when we are about to fall, and children fall down frequently. 

Buckle fractures take place when the bone is crushed and bends away from the growth plate. The flexibility of the bone usually causes stable, and greenstick fractures. These fractures can be repaired usually and rarely involove any complications 

Treatment of fractures in children

When a child goes through a fracture, he or she will have pain and cannot easily move the fractured area. Immediately a paediatric orthopaedic must be contacted. 

In other cases, even though the child will not have pain and will still be able to move, medical assistance should be sought out immediately. To reduce the bleeding, pain, and movement, a physician will put a splint on the fractured area. 

Facture’s treatment has a simple rule: the bones need to be aligned correctly and prevented from going out of place until the bones are cured. The specific treatment applied depends on the severity of the fracture, if it’s a closed or open fracture, and the particular bone involved in the fracture (a hip fracture treatment is different from a forearm fracture for example). 

The general treatments for child fractures are the following:

Cast immobilization

 Most fractures cure successfully after having been repositioned, a simple plaster or fibreglass cast is usually used.

Functional cast or brace

A cast, or brace, that permits restricted movement of the nearby joints is acceptable for some fractures. 

Traction

The treatment involves aligning a bone or bones by a gentle, steady pulling action. The pulling can be transmitted to the bone or bones using a metal pin through a bone or using skin tapes. It is a preliminary treatment commonly used in preparation for other secondary therapies.

Disorder’s in growing children

Children’s bones develop continually and remodel themselves extensively—growth begins from a part of the bone known as the growth plate. 

In remodelling, old bone tissue is replaced with new bone tissue. Most bone disorders come from the changes that take place in a growing child’s musculoskeletal system.

These disorders can worsen as the child grows. Other bone disorders can be inherited or take place in childhood for no known reason.

Growth plates disorder

Bones grow along with the rest of the child’s body. Children’s bones develop from soft areas of cartilage close to the ends of bones, known as the growth plates. 

When children grow up; the growth plates become solid bone. After the growth plates become solid, bones do not increase in length. That is the reason people do not become taller after a certain point in late adolescence. 

During childhood, injuries that happen to the growth plate can make the bone to grow abnormally.

Osteochondrosis refers to a class of disorders of the growth plate that happen when the child is growing instantly. Doctors are not sure what is the cause of osteochondrosis, but the disorders seem to run in families. 

Osteochondroses involve Köhler bone disease, Osgood-Schlatter disease, Legg-Calvé-Perthes disease, and Scheuermann disease.

An insufficient blood supply can damage the growth plate. Also, a separation from the bone or a minor misalignment can damage the growth plate as well. 

Damage on the growth plate restricts the growth of bones, distorts the joint, and causes long-lasting joint damage (arthritis).

Certain rare connective tissue disorders can affect the bones. They involve Marfan syndrome, osteochondrodysplasias and osteogenesis imperfecta. 

Osteopetroses are other rare hereditary disorders that raise the density of bones and cause bones to grow abnormally or both. 

Hip pain in children

Sometimes children may suffer from hip pains. Hip pain can occur due to the unique conditions of the child’s developing skeleton. It involves Perthes’ disease, slipped capital femoral epiphysis (SCFE) and apophyseal avulsion fractures of the pelvis. The relative likelihood of the different causes of hip pain changes with age.

The most common causes of hip pain in children are:

• Transient synovitis (irritable hip) occurring at 3-8 years
• Septic arthritis – any age (occurring at 0-6 years)

Bowing in children

It is common for long bones, particularly in the legs, to bow as a child grows. Bowing in the legs is seen when a child stands with their feet together, and a distinct space is witnessed between the knees and lower legs.

 A child’s risk of bowing is more when they are remarkably overweighed, but can also take place naturally and even into adolescence. The body fixes bowing naturally, but severe bowing that does not resolve naturally can be a sign of diseases such as Blount’s disease, rickets, or physiological genu varum.

All children need a lifestyle that helps build healthy bones. To increase a child’s bone density and strength, a diet rich in calcium, vitamin D, and protein is recommended. Also safe physical activity is best during the growing years.