In addition to the important and easily palpated Achilles tendon crossing the ankle on its posterior aspect, there are tendons crossing on the anterior, medial and lateral aspects of the ankle as well. These are, respectively, the tibialis anterior; the tibialis posterior; and the pair of peroneal tendons, longus and brevis. All are subject to overuse and inflammation, and when symptoms of that are present, the clinical diagnosis of tendinitis applies.
Structure and function
The tibialis anterior muscle is the most medial muscle of the anterior compartment of the leg. It stabilizes the ankle as the foot hits the ground during the contact phase of walking and dorsiflexes the ankle to help the foot clear of the ground during the swing phase. It also provides half of the force needed to 'lock' the ankle, as would be needed to kick a ball, for example: by providing an isometric contraction against its antagonists, the soleus and gastrocnemius, the tibio-talar joint is held in a fixed position.
The tibialis posterior originates on the posterior aspects of the tibia and fibula and crosses behind the medial malleolus to insert primarily on the navicular. It actively inverts of the foot and also plantar flexes the ankle, but its primary job is to support the medial arch of the foot. (Therefore, rupture or even stretching of this tendon can lead to flat feet.)
The peroneus longus and brevis tendons originate on the fibula and course together along the bone, with the brevis medial to the longus. They cross the ankle behind the lateral malleolus, in a groove covered by the superior peroneal retinaculum. The peroneus longus tendon then continues along the sole of the foot to the base of the first metatarsal bone. The peroneus brevis tendon inserts into a tuberosity at the base of the fifth metatarsal bone, on its lateral side. The peroneus muscles plantarflex and evert the foot.
Figure 1: Tibialis anterior
Figure 2: Tibialis posterior
Figure 3: Tendons of the peroneus longus and brevis
Tibialis Anterior tendonitis leads to pain and often swelling in the front of the ankle and into the mid foot. Symptoms typically occur in middle aged and older individuals. Symptoms are aggravated by standing and walking. Examination will often reveal tenderness over the anterior aspect of the ankle. Resisted dorsiflexion of the ankle against the examiner’s hand will often exacerbate symptoms.
Tibialis Posterior tendonitis presents as medial ankle and arch pain, worsened with prolonged standing and often in conjunction with a flat foot and prominent navicular. Resisted inversion and tenderness along the course of the tendon to its insertion on the navicular are hallmarks of this condition; if there is tenderness at the insertion but not along the course of the tendon, a symptomatic accessory navicular may be present.
The integrity of the Tibialis Posterior can be assessed with a “single heel rise”: having the patient stand up on the ball of the foot, with the contralateral foot off the ground entirely (that is, in a stork position). When viewed from behind, the intact tendon will be seen to invert the ankle. A lack of this motion suggests tendon failure. Note: that if the contralateral foot is kept on the ground and helps the patient stand on his or her toes, that assistance might prevent the tested tibialis posterior from generating enough force to invert the ankle, and the test can be falsely negative. Note also that some patients with severe tendinopathy may simply be unable to stand on one leg at all.
Patients with peroneal tendonitis present with pain and, occasionally, swelling near the posterolateral ankle. Resisted eversion will produce pain. Concomitant sural nerve irritation (by inflamed or damaged tendon) can lead to either decreased sensation or a burning over the lateral or outside aspect of the foot. There may be pain at the insertion of the brevis on the metatarsal, and if there was an acute event precipitating the pain, an x-ray should be obtained to exclude a bone injury.
With an injury to the retinaculum, the peroneal tendons may be free to slip in and out of their normal position: this condition is known as chronic subluxing peroneal tendonitis. Patients with this condition might describe a snapping sensation with activity; the subluxation can at times be reproduced on physical exam.
Figure 4: Location of pain and swelling in peroneal tendonitis
Figure 5: Location of pain and swelling in tibialis anterior tendonitis
figure 6: maybe something like this http://orthoinfo.aaos.org/figures/A00166F02.jpg
In the case of suspected peroneal tendonitis, plain weight-bearing x-rays are likely to show evidence of a high arched foot pattern, but the main goal of radiographs is to exclude a fracture of the fifth metatarsal, bony prominences that can irritate the tendons or lateral ankle arthrosis. An MRI can determine if there is tearing of the peroneal tendons.
Suspected tibialis anterior tendonitis can be evaluated with plain x-rays of the foot and ankle which might discover arthrosis.
Posterior tibial tendon disorders may be studied with weight bearing x-rays of the foot to assess the extent of the flatfoot deformity, if any; MRI can show damage to the tendon. Plain x-rays may also reveal an accessory navicular.
Although the incidence of ankle tendonitis has not been measured, anecdotal evidence suggests that posterior tibial and peroneal tendonitis is relatively common, whereas anterior tibial tendonitis is not except perhaps in younger athletes who have just increased training regiments or started running up and down hills (PMID: 19912714).
Anterior ankle pain, similar to that of tendinitis, is more commonly caused by ankle arthritis.
Lateral ankle pain may be caused by a sprain; pain near the base of the metatarsal may be a fracture.
Medial ankle pain near the posterior tibialis can be due to an accessory navicular.
Posterior tibial dysfunction can be seen in rheumatoid arthritis.
Pain along the course of the tibialis posterior may suggest attritional tearing. This should be detected and treated before the tendon ruptures, causing an acquired flatfoot.
Treatment options and Outcomes
Patients with ankle tendonitis treated successfully non-operatively. Modalities include anti-inflammatory medication, icing, ankle bracing, activity modification, physical therapy, an orthotic, and avoidance of precipitating activity with sudden cutting or changes of direction.
In patients with a large peroneal tendon tear or a bony prominence that abrades the tendon, surgical repair with resection of the irritant may be beneficial. A small peroneal tendon tear that does not respond to non-operative treatment can be debrided.
In patients with posterior tendon dysfunction, it may be necessary to transfer another tendon(usually the flexor hallucis longus) to support the arch. Removing an accessory navicular and reattaching the tendon to the can be helpful as well. In rare instances, an osteotomy (cutting the bones to recreate a more normal arch) may be needed.
Risk factors and prevention
Risk factors for peroneal tendonitis include overuse and a high arched foot. An orthotic with a recessed area under the first metatarsal head may be useful if a patient has a cavus (high arched) foot pattern.
Risk factors for tibialis anterior tendonitis include tight calves, obesity, and overuse.
Rheumatoid conditions may cause posterior tendon dysfunction
Patienst with Charcot-Marie-Tooth disease, an inherited neuromuscular disorder, have weakness of the foot and ankle muscles, with the peroneus longus, attaching to the base of the first metatarsal, relatively spared. The unopposed pull of this muscle against its weakened natural antagonists causes the classic deformity of marked cavus, as shown
Figure 7: The unopposed pull of the peroneus longus causes the classic deformity of Charcot-Marie-Tooth disease, namely, marked cavus of the foot. (source: https://upload.wikimedia.org/wikipedia/commons/e/ed/Charcot-marie-tooth_foot.jpg)
Tibialis anterior; peroneus longus; peroneus brevis; tendonitis; inflammation
Identifying the surface anatomy of the tendons themselves, as well as the navicular, 5th metatarsal and lateral retinaculum. Performing and interpretting the single heel rise test. Reconizing an incipient posterior tendon rupture.