Treating Flexor Hallucis Longus Tendon Dysfunction In Dancers
Professional dancers place a large amount of stress on their bodies, especially their lower extremities. In particular, ballet dancers are prone to developing foot and ankle problems.
Dancing en pointe or demi-pointe is a particular technique that many female ballet dancers perform and it can cause foot and ankle injuries. The ability to dance en pointe requires the dancer to undergo many years of training to build up her physical strength, balance and coordination. The technique involves excessive plantarflexion of the ankle and often puts the flexor hallucis longus (FHL) under a lot of strain, leading to tenosynovitis of the FHL tendon.
Tenosynovitis of the FHL is an entity that rarely occurs in the general population but can affect ballet dancers due to the strain on the tendon while the dancer is en pointe and demi-pointe. There are many factors that can predispose the patient to putting an increased amount of stress on the FHL and causing subsequent injury. These factors include ligamentous laxity, poor en pointe technique and pronation of the foot.
The FHL passes posterior to the medial malleolus deep to the flexor retinaculum along with the posterior tibial tendon, the flexor digitorum longus tendon, the tibial nerve and posterior tibial artery. The FHL then courses through a groove between the medial and lateral tubercles of the posterior portion of the talus. The tendon then passes under a fibro-osseous tunnel plantar to the sustentaculum tali before it courses toward its insertion into the plantar aspect of the hallux.
Pertinent Keys To The Physical Examination
A dancer with FHL tenosynovitis will often present with pain and swelling at the posteromedial aspect of the ankle and where the FHL courses around the sustentaculum tali. The symptoms are often exacerbated by jumping or attempting to go en pointe or demi-pointe. There may be pain in the posterior ankle in association with movement of the great toe. Patients often will complain of a “sticking” feeling in the posterior ankle and will state that something, usually the FHL, is getting caught in the posterior ankle region.
With longstanding cases, there may also be stenosis of the tendon. This can make the great toe freeze in the plantar position and subsequently require manual release of the contracture.
The physical exam will reveal tenderness over the FHL tendon and its associated sheath posterior and inferior to the medial malleolus. Resistance to flexion of the hallux will cause patients some pain. Passive range of motion to the hallux may produce some discomfort or may occasionally cause a snapping of the FHL.
Resistance to the FHL may be painful. Often, one can best elicit pain by placing the ankle in the plantar position and pressing on the FHL tendon region while moving the great toe into a forced dorsiflexion position. This will result in pain and a feeling of tenderness at the point of manual compression in the posterior ankle region. Take care to consider that symptoms of os trigonum pain can cause a similar sensation.
Furthermore, flexor hallucis longus pain may also cause tarsal tunnel type symptoms so take care to differentiate between the two. Tarsal tunnel pain will not be worse with forced plantarflexion of the ankle and often, direct pain on the nerve does not cause irritation like it will with FHL tendon symptoms.
Essential Insights On Imaging
Take radiographs to rule out an os trigonum. An os trigonum is an accessory ossicle to the lateral tubercle of the posterior aspect of the talus and will present with similar symptoms to a tenosynovitis of the FHL. This ossicle can become irritated and cause pain during plantarflexion of the ankle.