Growth Plates
Growth plates are defined as the area of new bone growth which is made up of cartilage at the end of our long bones. There are 2 growth plates per long bone, at each end of bones such as the femur, tibia, fibula, radius and ulnar, which are found in our arms and legs. The long bones grow from contributions of new bone from the growth plates which add length and width to these bones.
Due to the soft nature of growth plates, they are weaker than solid bone which makes them more vulnerable to injury during development. The growth plates are even sometimes weaker than the surrounding tendons and ligaments and this often results in up to 30% of fractures in children happening around the growth plates.
As we grow in childhood, these areas harden into solid bone, and this is then known as a closed growth plate, where the bones are then no longer growing. Growth plates normally close near the end of puberty, which is around 13-15 years old for girls, and 15-17 years old for boys.
Before the closure of growth plates, there can be a few issues in children/adolescents as they grow. One of these issues are fractures, which most often occur in the bones of the fingers, forearm and lower leg. Most of these fractures heal with no future bone growth being affected, however some can cause problems later on in life if they are not effectively managed. These issues can be caused by a bone that does not heal straight, or bones that heal longer or shorter than expected.
Other common injuries include overuse/repetitive stress injuries, which can affect growth plates in children and teenagers. Overuse injuries are caused by repeating the same movement over and over, often while playing sport. These injuries include Severs disease, and Osgood Schlatters disease.
When looking at Severs disease, there is swelling and irritation of the growth plates in one or both of our heels. There is usually tenderness in the heel and this can lead to the following symptoms, where the pain is usually worse during or after an activity:
- Swelling and redness in the heel,
- Stiffness in the feet when waking up,
- Limping or walking on the toes, or
- Pain in the heel when it is squeezed on both sides.
Severs disease normally occurs during a growth spurt during puberty. Throughout the process of a growth spurt, bones, muscles, and tendons all grow at different rates. Muscles and tendons often become tight and pull on the growth plates of the heel as they are not keeping up with the rate of bone growth and only catch up on the growth a little later as they lag behind.
Osgood schlatters refers to the swelling and irritation of the growth plate at the top of the shin bone (tibia). It usually goes away when we stop growing and doesn’t generally cause lasting problems. Children who struggle with Osgood Schlatters normally present with pain and swelling below the kneecap, which is made worse by running, jumping, and going up stairs and hills. It can be in just one or both knees.
These overuse injuries happen to children in their growth spurts and are caused by activities and sports that pull on tightened structures which injure these growth plates. Sports and activities that involve a lot of jumping and running on hard surfaces such as basketball, gymnastics and running track often result in these and other injuries.
Treatment includes cutting down or limiting activities that are causing pain, PRICE principles, as well as heel gel caps and supportive inserts to lower stress (load) and impact on affected heels and knees where indicated in patients. Physiotherapy is also very important in the management, with specific emphasis being put on pain management, soft tissue release, myocardial release, oedema massage, ultrasound and an exercise programme with specific focus on stretching and strengthening affected parts of the body to help the body adapt to the changes it is experiencing.
Growth plate fractures are defined into the Salter-Harris classification, where there are 5 types of fractures, namely:
- Type I is a fracture through the growth plate where the epiphyses (growth plate) separates from the shaft of the bone,
- Type II is a fracture through the shaft and the growth plate, forming a triangular shaped fragment. This is the most common type of growth plate fracture, accounting for 75% of fractures.
- Type III is a facture through the growth plate and the end of the bone. These types of fractures can be quite unstable and almost always require accurate realignment and possible surgery. These are less common, accounting for about 8% of growth plate fractures.
- Type IV is a fracture through the shaft, growth plate and the end of the bone that affects the joint. These can also be quite unstable and need realignment and possible surgery.
- Type V is a fracture where is a compression force to the growth plate. These fractures are quite uncommon and may result in the growth plate being partly or completely destroyed so the bone no longer continues to grow.
Type I and Type II are the most common types of fractures and do well with conservative management. They are rarely associated with growth disturbances. The other 3 classes of fractures are less common and generally come with higher risk.
The 5th type of fracture is rare but has increased potential for growth disturbances. It is important to remember that they all require close monitoring for effective management of the healing process.
Physiotherapy is essential in the graded rehabilitation process in order to return to activities of daily living and sport. Our aim is to guide patients towards effective and controlled strengthening and stretching. Brace prescription is sometimes addressed, depending on the presentation. In order to prevent possible injuries and fractures, involvement in sport and high impact activities should be closely monitored and adjusted as needed.
