Peroneal tendonitis occurs when the peroneal tendons become inflamed. This happens when there is an increased load and overuse of the tendons, leading to them rubbing on the bone.
This friction causes the tendons to swell. Over time, the tendons will thicken in size to try and manage the increased load more efficiently.
Peroneal tendonitis is particularly common in athletes and especially runners, as they are more likely to make their feet roll outwards, causing friction between the tendon and bone.
The peroneal tendons are located in the foot, attaching muscle to bone. They assist with weight bearing and stability.
A tendon is a band of tissue that attaches muscle to bone.
There are two peroneal tendons in each leg. They run side by side down the lower leg bone (fibula) and behind the bony lump on the outside of the ankle called the lateral malleolus.
One peroneal tendon attaches to the outside of the foot at the base of the little toe (fifth metatarsal). The other tendon goes underneath the foot and attaches to the inside of the arch.
The peroneal tendons provide stability to the ankle when it is bearing weight and protects it from sprains. They also help turn the foot out and stabilize the arch when walking.
People who take part in a sport that involves repetitive ankle motion are most prone to peroneal tendonitis.
Factors that can contribute to peroneal tendonitis include:
- a sudden increase in training, particularly weight-bearing activities, such as walking, running, and jumping
- improper training techniques
- inadequate or unsupportive footwear
There are also some other issues that can increase a person’s risk of developing peroneal tendonitis:
- higher foot arches
- lower limb muscles and joints not working well together
- imbalanced muscles in the lower limbs
If someone fails to complete a rehabilitation program following an ankle injury, such as a sprain, they are also more likely to develop peroneal tendonitis.
Over time, the damaged peroneal tendons will thicken as scar tissue tries to repair the damaged area. This makes the tendons weaker and more prone to tearing.
Peroneal tendonitis can either be acute, meaning that it comes on suddenly; or it can be chronic, meaning that it develops over time.
In both cases, there are some common symptoms:
- pain at the back of the ankle
- pain that worsens during activity and lessens during rest
- pain when turning the foot in or out
- swelling at the back of the ankle
- instability of the ankle when bearing weight
- the area is warm to the touch
To begin with, the doctor will discuss the person’s medical history with them. This will often point to overuse, increased activity, or some other cause of peroneal tendonitis.
It is important to determine that the pain is in the peroneal tendons and not the fibula, as this could indicate a different problem.
A physiotherapist or doctor will use a variety of techniques in a physical exam to look for symptoms, generally by moving the foot and ankle into different positions and applying pressure.
An X-ray, ultrasound, or MRI scan might also be used to rule out any breaks, identify abnormal swelling or scar tissue, and to further help with diagnosis.
Because overuse of the tendons often causes peroneal tendonitis, rest is crucial to help them heal.
The individual should avoid walking or any other activities that may aggravate the injury until the pain has gone. The area needs time to recover and, in time, the pain will lessen.
Nonsurgical treatments that are common in cases of peroneal tendonitis include:
- Immobilization: Stopping the foot and ankle from moving using a boot or support.
- Medication: Anti-inflammatory drugs, such as ibuprofen, can help relieve pain and swelling.
- Physical therapy: Ice, heat, and ultrasound therapy can reduce pain and swelling. Once the symptoms improve, introduce exercises that strengthen the muscles and improve balance and motion.
- Bracing: Some people may require a brace for use during activities that involve repetitive ankle motion.
- Cortisone injection: In rare cases, doctors may recommend this powerful anti-inflammatory medication. However, if cortisone is injected into the peroneal tendons, there is a chance of rupture.
Surgery is rare when treating peroneal tendonitis, and it is only usually considered as a last resort if nonsurgical methods are not helping to reduce pain.
If tissue around the tendons is causing irritation, the surgeon may undertake a procedure called tendon release to remove it.
If a tear has occurred because of overuse of the peroneal tendons, the surgeon will also look to perform tendon repair.
There are several things that people can do to try and avoid getting peroneal tendonitis:
- Wearing appropriate footwear that properly supports the foot and ankle.
- Stretching the calf and peroneal muscles. If this is during recovery, the patient should wait until inflammation and pain have gone.
- Increasing training workload gradually.
- Maintaining a level of activity throughout recovery. This is particularly important for sportspeople during the off-season.
People experiencing peroneal tendinitis will usually make a full recovery, but it will take time. It is essential not to rush back to activities too soon.
Acute injuries will recover quicker than chronic injuries, but in both cases rehabilitation is crucial. It is important for people to complete the individual program they are given in order to reduce the risk of repeat injury.
In the case of athletes, the outlook is very good. In almost all cases of peroneal tendonitis, they will be able to return to their sport at the same level as they were before the injury.
However, this can only happen if people follow instructions for rehabilitation from their physical therapist and doctor.
If left untreated, peroneal tendonitis can lead to a tear. In turn, this can increase the chance of sprained ankle or nerve damage. As a result, it is extremely important to get it treated as soon as possible and follow a recovery program.