Posterior Tibial Tendinitis – The Clinical Syndrome
Posterior tibial tendinitis is being seen with increasing frequency in clinical practice as jogging and other aerobic exercises have increased in popularity. The posterior tibial tendon is susceptible to the development of tendinitis and is particularly subject to repetitive motion that may result in microtrauma, which heals poorly because of the tendon’s avascularity. Running, Irish folk dancing, and high-impact aerobics routines are often implicated as the inciting factor of acute posterior tibial tendinitis.
Tendinitis of the posterior tibial tendon frequently coexists with tendinitis of the Achilles tendon and bursitis of the associated bursa of the posterior ankle joint, creating additional pain and functional disability. Calcium deposition around the tendon may occur if the inflammation continues, making subsequent treatment more difficult. Continued trauma to the inflamed tendon ultimately may result in tendon rupture. In contrast to Achilles tendon rupture, which often occurs without warning after acute trauma, rupture of the posterior tibial tendon tends to be secondary to chronic tendinosis and degeneration of the tendon over time. Rupture of the posterior tibial tendon occurs three times more commonly in women, with peak incidence in the fifth and sixth decades. A left-sided predominance is seen, and rupture is unilateral more than 90% of the time.
What are the Symptoms of Posterior Tibial Tendinitis
The onset of posterior tibial tendinitis is usually gradual, occurring after overuse or misuse of the ankle joint. Inciting factors include activities such as running and sudden stopping and starting as when playing tennis or doing high-impact aerobics routines. Improper stretching of the gastrocnemius and tendons of the posterior ankle before exercise has been implicated in the development of posterior tibial tendinitis and acute tendon rupture. The pain of posterior tibial tendinitis is constant and severe and is localized over the medial longitudinal arch. Flattening of the medial longitudinal arch occurs, and over time a severe pes planus deformity results. Significant sleep disturbance is often reported. Weight bearing on the affected ankle and foot reveals these deformities and heel valgus, plantar flexion of the talus, and forefoot abduction. Patients with posterior tibial tendinitis or rupture or both exhibit weak inversion of the ankle and foot. A creaking or grating sensation may be palpated when passively plantar flexing and inverting the foot. As mentioned, the chronically inflamed posterior tibial tendon may rupture with stress or during vigorous injection procedures into the tendon itself.
How is Posterior Tibial Tendinitis diagnosed?
Plain radiographs, ultrasound imaging, and magnetic resonance imaging (MRI) are indicated for all patients with posterior ankle pain; weight-bearing radiographs often reveal the deformity associated with rupture of the posterior tibial tendon. Based on the patient’s clinical presentation, additional tests, including complete blood count, erythrocyte sedimentation rate, and antinuclear antibody testing, may be indicated. MRI of the ankle is indicated if joint instability is suspected. Radionuclide bone scanning identifies stress fractures of the tibia not seen on plain radiographs. Injection of the posterior tibial tendon with local anesthetic and steroid serves as a diagnostic and therapeutic maneuver.
Posterior tibial tendinitis generally is identified easily on clinical grounds. Because a bursa is located between the Achilles tendon and the base of the tibia and the upper posterior calcaneus, coexistent bursitis may confuse the diagnosis. Stress fractures of the ankle and hindfoot may mimic posterior tibial tendinitis and may be identified on plain radiographs or radionuclide bone scanning.
Initial treatment of the pain and functional disability associated with posterior tibial tendinitis should include a combination of nonsteroidal antiinflammatory drugs (NSAIDs) or cyclooxygenase-2 (COX-2) inhibitors and physical therapy. Local application of heat and cold may be beneficial. The patient should be encouraged to avoid repetitive activities responsible for the evolution of the tendinitis, such as jogging. For patients with tendinitis of the posterior tibial tendon who do not respond to these treatment modalities, careful injection of the area underneath the deltoid ligament just below the medial malleolus with local anesthetic and steroid may be a reasonable next step. Ultrasound guidance may increase the accuracy of needle placement and decrease the incidence of needle-related complications. Surgery is required for patients who have sustained rupture of the posterior tibial tendon.
Complications and Pitfalls
The possibility of trauma to the posterior tibial tendon from the injection itself is ever present. Tendons that are highly inflamed or previously damaged are subject to rupture if they are directly injected. This complication can be greatly decreased if the clinician uses gentle technique and stops injecting immediately if significant resistance to injection is encountered. Approximately 25% of patients report a transient increase in pain after this injection technique, and patients should be warned of this possibility.
The posterior tibial tendon is a strong tendon but also is very susceptible to rupture. Injection of the tendinitis is extremely effective in the treatment of pain secondary to the previously mentioned causes of posterior ankle pain. Coexistent bursitis and arthritis may contribute to posterior ankle pain and may require additional treatment with a more localized injection of local anesthetic and methylprednisolone acetate.
The described technique is a safe procedure if careful attention is paid to the clinically relevant anatomy in the areas to be injected. The use of physical modalities, including local heat and gentle range-of-motion exercises, should be introduced several days after the patient undergoes this injection technique for ankle pain. Vigorous exercises should be avoided because they would exacerbate the symptoms. Simple analgesics and NSAIDs may be used concurrently with this injection technique. Tendon rupture requires surgical repair to protect the ankle and foot from further damage.