You have broken your arm or another sturdy bone in your body and with such an event, naturally, there are feelings of fear, anxiety and pain. You might be worried about whether your arm will be the same again, if the bone will heal, if you can get back to gardening or playing sport and when you can start using the arm again.

The great thing about the human body is that is it incredibly resilient and has the capacity to renew. In fact, your body does this on a daily basis with your skin and the lining of your gastrointestinal tract. And, rest assured, the skeletal system is also able to heal itself just like the skin when there is a papercut. What makes it trickier is that the healing takes place inside of us, invisible to the naked eye.

So, let’s dive under the skin and take a look at how bones heal after a fracture.

The Tissue Healing Process

The healing process can be separated into three phases: the inflammation phase, the proliferation phase and the remodelling/maturation phase. Each of these phases occur at different times but there is an overlap between each phase.

Inflammation

0- to 72 hours

This first phase begins as soon as you have broken a bone. The two aims of the inflammation phase is to stop bleeding at the site of injury and to protect the site from infection. Inflammation, is typically characterised by redness, heat, swelling and pain. And this has to do with the measured and timely events occurring in the inflammation phase.

In the inflammation phase, blood vessels contract to prevent blood loss, whilst at the same time, blood is also shunted to the area to flood the injury with white blood cells and platelets. Altogether, this army of cells protects against infection, cleans up debris and forms a clot. This clot can be likened to the scab you see after a papercut.

The site of injury is also flooded with a chemical soup attracting more immune cells to the area, promoting other steps in the healing process and increasing sensitivity of nerves sensing pain. Hence, there is quite a bit of soreness at the fracture site.

Proliferation phase

24-48 hours post injury, can last 2-3 weeks

In the proliferation phase, the aim is to rebuild the broken bone. The building blocks required for rebuilding bone are collagen (scaffolding), extracellular matrix (like cement) and of course, the bone cells which lay down bone. These building blocks are laid down in a non-organised manner but continues to serve the proliferative phase for bone healing. Additionally, this area needs to be connected to the ‘power grid’, and so blood vessels and nerves are also integrated into this process.

Remodelling or maturation phase

3+ weeks to 2 years

During the remodelling phase, further refining of the tissue healing occurs where the correct collagen is laid down in an organised and structured manner. Unnecessary cells and blood vessels are removed from the area.

Around the fracture site, a healthy ‘glue’ has formed which is now beginning to set. The setting of the ‘glue’ and the processes taking place within the ‘glue’ and fracture site takes 6-8 weeks. After 8 weeks, a further 4 weeks is required for the ‘glue’ to be ‘sanded down’, refined and set firmly. This is why you are often in a plaster cast/immobilised for a period of 6-8 weeks with a re-imaging of the fracture site afterwards to make sure the bone has healed.

In short, you may not be able to do particular movements and activities with the broken arm until 6-8 weeks. A further 4 weeks may be added onto this depending on the complexity of the fracture.

Exercising during and after a fracture

During this time of immobilisation, there will be some exercises you can still complete to maintain some strength in the non-affected areas. It is crucial to find exercises you can still complete safely because a period of immobilisation reduces muscle mass up. For example, in a hospital setting where one confined to bedrest for one week only, just under half of muscle mass is lost.

After your period of immobilisation, it is equally important to re-strengthen the area with exercises that are safe and specific to your needs. Gradually returning to exercises and increasing the exercise difficulty will further help strengthen the muscles and bone for complete bone healing.

The healing process is amazing and complex process that allows our tissues to regain its composure, structure and strength. Under the guidance of a physiotherapist, you will be able to maintain strength during your immobilisation phase and afterwards, you will be able to strengthen and return to the activities you have sorely missed over the last 6-8 weeks.