Symptoms
Characteristic of the peroneal tendon syndrome is pain in the area of the outer ankle, which can occur mainly when the ankle is strained (especially when the inner side of the foot is lifted) but sometimes also at rest. A so-called “tarnishing pain” is also frequently reported, which occurs mainly in the morning after getting up or after sitting or lying down for a long time. This pain can also be accompanied by swelling in the area of the outer ankle as well as reddening and warming of the skin in this area.
In some cases, a pressure-painful thickening and hardening of the peroneal tendons behind the outer ankle can be felt, and a muscular weakness can be felt when trying to lift the outside of the foot. The latter symptom leads to a slightly limping gait pattern in the affected patient. If the inflammatory process spreads to the sural nerve, which accompanies the peroneal muscles and is responsible for the sensitive innervation of the outer side of the foot and the heel, it can also lead to sensory disturbances and/or a burning sensation in the skin of the outer foot.
Diagnosis
The diagnosis of a peroneal tendon syndrome can usually be made on the basis of the patient’s medical history, if the patient reports characteristic pain in the area of the outer ankle and a preceding mechanical additional load on the foot.During the physical examination of the patient, a hollow foot and a forefoot position that tends inwards to a straight stance is usually noticeable, often accompanied by an ankle axis that deviates in an O-shape. If the patient’s medical history and physical examination are not clear, imaging procedures can support the diagnosis. Different imaging techniques can be used, depending on the issue at hand and which differential diagnoses should be excluded.
Ultrasound examination (sonography) is the method of choice for evaluating tendons, as it is a cost-effective, simple and time-saving method for detecting inflammation and tears in the tendons or tendon sheaths. Magnetic resonance imaging (MRI) is used to expand or supplement ultrasound diagnostics and enables even more precise assessment of inflammatory processes and tendon tears. The oedema in the area of the outer ankle, which is typical of peroneal tendon inflammation, can also be displayed more clearly in the MRI.
The classic x-ray of the foot primarily provides information about pathologies of the bony skeleton of the foot (fractures), changes in the ankle (arthritis) and possible foot malpositions (hollow or flat foot). Blood samples may also be useful for research into the causes of the foot, in order to exclude or detect infections and inflammatory rheumatic diseases in the laboratory on the basis of inflammation parameters. The first therapeutic measure for a peroneal tendon syndrome is usually a conservative attempt, in which the main aim is to relieve the tendon in order to give the inflammation a chance to subside.
This can be achieved by splinting, bandaging or taping the ankle, which causes temporary immobilization of the ankle. The overloading movements or the previously exercised activity should also be reduced or even completely stopped for a few weeks, especially activities with rapid changes of direction. Cooling the outer ankle with an ice pack at intervals of 10-20 minutes can also help to reduce symptoms.
Parallel treatment with pain and anti-inflammatory drugs (e.g. ibuprofen or diclofenac) is possible, which can reduce the inflammation in the peroneal tendons. In some cases, a direct injection of a cortisone-anesthetic mixture into the immediate area of the inflamed tendons can also be helpful to achieve local inflammation and pain inhibition. If the cause of the inflammation is a bacterial infection, antibiotic therapy is sometimes initiated.
In addition, it is advisable to consult a physiotherapist, with whom specific strengthening exercises of the lower leg musculature can be carried out in order to compensate for possible muscular imbalances and strengthen the fibula. If foot malpositions are present, compensating footbed insoles can also lead to a significant relief of the peroneal tendons, so that, for example, an insole with a cut-out area under the first metatarsal bone can correct the malposition in patients with high arches. If conservative therapy fails, if the inflammatory process is very severe and advanced, or if there are possibly anatomical bone variants such as prominent peroneal tubercle or a bone spur, a surgical therapy procedure can be a good alternative.
The surgical method depends largely on the goal pursued and the underlying cause of the peroneal tendon syndrome. It is possible to clean the inflamed tendons (debridement, synovectomy), smooth the tendons or their trough, repair tendon tears or lacerations, restore the peroneal retinal cavity or resect the peroneal tubercle. In the case of massive foot malpositions, even a change in the rear foot bone arrangement (lateralizing calcaneus osteotomy) or stabilization of the ankle outer ligaments may be the only therapy to remedy the problem.
