Drivers of Arthrofibrosis
Arthrofibrosis is an excessive wound healing response to an injury or surgery that creates internal scar tissue, pain and a lack of range of movement. Whether an individual develops arthrofibrosis depends on a large number of interacting factors. Understanding what these drivers are can sometimes help to identify the most appropriate approaches to treatment as well as lifestyle changes.
The primary drivers of arthrofibrosis are the most significant and powerful promoters of fibrosis, and include our genetic predisposition, a history of surgery and injury. Some, such as infections and autoimmune conditions, can be treated once they have been identified, and testing for these is important. However, some genetic predispositions are more difficult to treat. Because wound healing requires the precise regulation of a large number of biological systems, including immune function, blood clotting and clearance of dead cells, there are a large number of genetic differences that can impact our ability to heal in a normal way.
Secondary drivers of arthrofibrosis can often be addressed once we are aware of them. For example, aggressive exercise and injurious overpressure of the affected limb can be stopped, and diets high in sugar and low in fibre can be changed to a diet high in fruit and vegetables, seeds and nuts.
In most cases of arthrofibrosis there will be multiple factors that all contribute some amount to the outcome and there may be other drivers not mentioned here. Please consult your doctor to understand what your drivers may be, and discuss treatments.
Primary Drivers
Insult
Insults include anything that creates inflammation, bleeding and a wound healing response. Injury and surgery are the major insults that create arthrofibrosis, and the risk appears to be particularly high after bone is cut, for example, in ACL reconstructions and knee replacement surgeries. However, injuries that cause arthrofibrosis also include repeated micro-traumas that may not be noticed, which often occurs in shoulder arthrofibrosis. Bleeding is a powerful driver of fibrosis and should be avoided where possible.
Immobility
Immobilisation of the affected limb over a number of days or weeks is well known to be a powerful driver of arthrofibrosis. Arthrofibrosis can be created in healthy young animals without known predispositions by immobilising a limb.
Predisposition
Predisposition means that a person’s body has a tendency to produce excessive scar tissue. This can be caused by a large number of genetic differences in the way the body functions, which may not be apparent under normal conditions. Differences in blood clotting pathways is one example. A common condition called Mannose-Binding Lectin (MBL) deficiency likely predisposes people to fibrosis. MBL binds to pathogens and sick cells to identify them for clearance by the immune system, and is necessary for healthy healing. Other predispositions include autoimmune disorders such as ankylosing spondylitis, lupus (SLE), Grave's disease, rheumatoid arthritis, mixed connective tissue disease. Testing for these can assist by identifying an appropriate treatment. A history of surgery on the affected joint also increases the risk of arthrofibrosis, likely because of the myofibroblasts (the cells that make fibrosis) accumulate after each surgery and can be re-activated.
Hypoxia
Hypoxia means a lack of oxygen, and it is one of the most powerful drivers of arthrofibrosis. Hypoxia results from surgery and injury when blood vessels are damaged, and as a result of the inflammatory processes. Hypoxia also occurs when a tourniquet is applied during surgery or physiotherapy to deliberately restrict blood flow. Some physiotherapists apply a tourniquet during exercise of the affected limb, in a practice known as blood flow restriction, and this carries a high risk of activating arthrofibrosis. The science suggests that hypoxia should be avoided where possible for people with arthrofibrosis. Massaging of the affected limb can help to increase blood flow, but care should be taken around a recently operated joint.
Inflammation
Contributors to inflammation include diabetes, osteoarthritis, metal allergy, genetic differences and other conditions. An incorrectly positioned or sized prosthesis or graft can also create inflammation, and should be screened for.
Infection
Infection can create local or systemic inflammation that activates myofibroblasts (the cells that cause fibrosis) in the affected joint. These include joint infection, gum infections (P. gingivalis), respiratory infections (flu, covid) and other infections. Infection should be ruled out as a cause of arthrofibrosis or treated appropriately as soon as possible.
Secondary Drivers
Aggressive Exercise
Aggressive exercise of the affected limb increases inflammation and has the potential to activate myofibroblasts (the cells that make fibrosis) and promote arthrofibrosis. For some people even very gentle exercise of the affected limb is not tolerated for an extended period following surgery. In addition, painful and aggressive overpressure (stretching) of a joint to increase range of motion can tear tissues and activate myofibroblasts and inflammation, and should be avoided. Stretching of the affected limb should always be controlled by the patient to avoid damage. Exercise and therapy tolerance varies greatly in affected joints, and all forms of exercise of the affected limb should be treated with great caution and stopped if there is an adverse reaction.
Lack of Essential Nutrients
A healthy gut is essential for a healthy body and inflamed intestines are a significant factor in systemic low grade inflammation. A diet that is high sugar and low fibre promotes harmful gut bacteria, but over time these bacteria can be out-competed by good bacteria after switching to a healthy diet. Healthy diets are high in plant products such as fruit, vegetables, seeds and nuts, and usually provide adequate amounts of essential vitamins and minerals. However, some people with chronic inflammation require supplements to maintain adequate levels of nutrition. An example of this is iron. Testing of essential vitamins and minerals can identify where there are deficiencies that need correcting, please ask your doctor.
Lack of Sleep
Quality sleep is essential for a healthy body, and many things can adversely impact sleep quality and quantity. Many people have undiagnosed sleep apnoea that restricts oxygen intake and creates hypoxia, a powerful driver of fibrosis. Please ask your doctor about sleep apnoea if you snore, regardless of your age and weight. Poor sleep hygiene, insomnia, pain, stress, other conditions also contribute to a lack of good sleep, and can adversely affect our ability to heal normally.
Stress
Psychological and physical stressors result in hormonal responses that promote chronic low grade inflammation and fibrosis. Emotional stressors should be avoided where possible. Mindfulness and meditation training and practice are helpful life skills that can assist healthy healing. Please ask your doctor about stress reduction if necessary.
Legal Disclaimer
The materials presented in this site are provided voluntarily as a public service. It is of a general nature, based on the scientific literature. The information and advice provided is made available in good faith but is provided solely on the basis that readers will be responsible for managing their own assessment of the matters discussed herein and that they should verify all relevant representations, statements and information. Please consult your doctor.