The major tendon injuries around the ankle are to the posteromedial (flexor), mid-posterior (Achilles) or posterolateral (peroneal) tendons. Tendon disorders are particularly common in middle-aged active people. Tendon disorders comprise 30% to 50% of all sports-related injuries12 and there is a lifetime risk of 52% that elite long-distance runners will suffer from an Achilles tendon injury.13 Despite the high prevalence there is still much to learn about the aetiology and pathogenesis of these injuries.

Flexor hallucis longus (FHL) tendon
FHL tendinopathy is characterised by posteromedial pain during shooting. The moving FHL can be palpated posterior to the medial malleolus during active or passive flexion movements of the great toe with the ankle in 10°to 20°of plantar flexion. With tendinopathy there is pain on palpation and active resistance testing. Crepitus might be present and is suggestive for FHL tenosynovitis. Flexor hallucis longus tendinopathy is frequently seen in combination with posterior ankle impingement syndrome.
Achilles tendon
Achilles tendinopathy is a clinical diagnosis characterised by pain, swelling and impaired load-bearing capacity. The pain is typically felt in the mid-portion or the tendon, but can also be insertional. A common contributing factor is a rapid increase in activity. The phrase “too much, too soon” is frequently heard in the patient’s history. Initially, pain is only present during warm-up or after activity. Interestingly, recent reports indicate that the condition is being seen more and more in completely non-active individuals, making the aetiology ever more difficult to determine. Rest may initially decrease the symptoms among active individuals, but frequently symptoms return with an increase in activity. In more advanced stages, the tendon may become painful during rest and activities of daily living.

On examination, the swelling in the tendon mid-portion may be obvious. Achilles tendon pain is usually localised to the tendon itself, mainly ventral-deep side, and the pain is referred to other regions. In the presence of swelling with pain on palpation, there is a high probability that histology will show features of tendinosis.

The majority of patients with Achilles tendniopathy are treated with an eccentric strengthening programme. There are also a range of other adjuvant therapies which can be considered.

Peroneal tendon pathology
The peroneal tendons can become injured either as a result of acute trauma or from overuse (tendinopathy).

An awareness of peroneal tendon dislocation or subluxation is important as these conditions have a similar clinical presentation to an acute lateral ligament sprain. Making the correct diagnosis is important as the conditions are managed very differently. Peroneal dislocations typically involve either inversion of a dorsiflexed ankle or forced dorsiflexion of the everted foot. Both can cause avulsion of the superior retinaculum from the fibula, allowing the tendons to dislocate anterior to the fibula. Patients may present late with lateral ankle pain and an associated snapping sensation. It may be possible to replicate the dislocation with plantar flexion and circumduction.

XRs may show a “Fleck sign”. This is an avulsion from the lateral malleolus and is pathognomonic.4 The avulsion is seen laterally and about 2-3cm above the tip of the lateral malleolus. An ultrasound may also show the subluxation dynamically.

There is a high rate of recurrence with conservative treatment. As a result, surgical repair is generally advocated in most athletes and a referral to an orthopadic surgeon is suggested. This involves the direct repair of the superior peroneal retinaculum as well as a reconstruction of the peroneal groove and retinaculum.

Tibialis posterior tendon disorders
Disorders of the tibialis posterior tendon can cause medial foot and ankle pain. They are very poorly tolerated and are often refractory to treatment. Key clinical signs include pain and tenderness about the medial ankle (especially posterior to the medial malleolus), pes planus, pain or weakness with resisted ankle inversion, and a “too many toes” sign. Failure of the calcaneus to move into normal varus with calf raises is another important sign.

Initial treatment requires load reduction using a medial posted orthotic and in some cases a moonboot. Exercises to strengthen the tibialis post tendon are also important.

To learn more about the aetiology of tendinopathy as well as the characteristic history, examination and investigation findings, review the “Tendon” module. This has been developed by the clinicians from FC Barelona.

Dr Pieter D'Hooghe

Orthopaedic Surgeon