Posterior tibialis tendonitis is a clinical syndrome characterized by sharp, constant, and severe inner ankle pain. This painful condition is often seen as a result of acute eversion injuries to the ankle although it is also seen with overuse or misuse of the ankle in the foot, as seen in long-distance running with improper shoes. Recently, there have been a number of reports of posterior tibialis tendonitis in Irish dancers as a result of the “leap-over move” that is a common part of their dance routine (Fig. 171.1). Patients suffering from posterior tibialis tendonitis will often splint the inflamed posterior tibialis tendon by adopting an antalgic gait to avoid using the affected tendon. This dysfunctional gait may cause a secondary bursitis and tendonitis around the foot and ankle, which may serve to confuse the clinical picture and further increase the patient’s pain and disability. Pain on palpation of the posterior tibialis tendon as it passes behind the medial malleolus is a consistent finding in patients with posterior tibialis tendonitis as is exacerbation of pain with active resisted inversion and passive eversion of the ankle (Fig. 171.2). The inner aspect of the ankle may feel hot and appear swollen, which may be misdiagnosed as superficial thrombophlebitis or cellulitis. Patients suffering from posterior tibialis tendonitis will also often complain that it feels like their shoes are rubbing the inside of their ankle raw, although on examination the skin appears normal. A creaking or grating sensation may be palpated when passively inverting and everting the ankle. Untreated, posterior tibialis tendonitis will result in increasing pain and functional disability calcium deposition around the tendon occurring, making subsequent treatment more difficult. Continued trauma to the inflamed tendon ultimately may result in tendon rupture (Fig. 171.3). Rupture of the posterior tibialis tendon will result if disruption of the normal architecture of the foot results in the loss of the arch of the foot and development of the pes planus deformity (Fig. 171.4).

Plain radiographs are indicated in all patients who present with medial ankle pain. Based on the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging and/or ultrasound imaging of the ankle is indicated if posterior tibialis tendonitis, rupture, or joint instability is suggested (Figs. 171.5, 171.6 and 171.7). Radionuclide bone scanning is useful to identify stress fractures of the tibia not seen on plain radiographs. The injection technique described later serves as both a diagnostic and a therapeutic maneuver.

The posterior tibialis muscle plantar flexes the foot at the ankle and inverts the foot at the subtalar and transverse tarsal joints. The muscle finds its origin from the posterior tibia and fibula. The tendon of the muscle passes behind the medial malleolus, running beneath the flexor retinaculum, and into the sole of the foot where it inserts on the navicular bone (Fig. 171.8). The posterior tibialis tendon is susceptible to the development of tendonitis as it curves around the medial malleolus.

Ultrasound-guided injection technique for posterior tibialis tendonitis involves blocking the inflamed tendon as it passes behind the medial malleolus. The technique can be carried out by placing the patient in the supine position with the arms resting comfortably along the patient’s chest and the affected lower extremity externally rotated (Fig. 171.9). A total of 4 mL of local anesthetic and 80 mg of depot steroid is drawn up in a 12-mL sterile syringe. The medial malleolus is then identified by palpation (Fig. 171.10). A linear highfrequency ultrasound transducer is placed in a longitudinal plane, with the middle of the ultrasound transducer lying over the posterior border of the medial malleolus (Fig. 171.11). This will put the ultrasound transducer parallel to the posterior tibialis tendon as it passes behind the medial malleolus. An ultrasound survey scan is taken. The posterior tibialis tendon can be seen lying just behind the medial malleolus as a fibular linear structure (Figs. 171.12 and 171.13). When the posterior tibialis tendon is identified on ultrasound imaging, the skin is prepped with anesthetic solution, and a 1½-inch, 22-gauge needle is advanced from the superior border of the ultrasound transducer and advanced utilizing an in-plane


approach with the trajectory being adjusted under real-time ultrasound guidance until the needle tip is resting in proximity to the posterior tibialis tendon but not within the tendon itself (Fig. 171.14). When the tip of needle is thought to be in satisfactory position, after careful aspiration, a small amount of local anesthetic and steroid is injected under realtime ultrasound guidance to confirm that the needle tip is in proximity to the posterior tibialis tendon, but not within the tendon itself. There should be minimal resistance to injection. After needle tip placement is confirmed, the remainder of the contents of the syringe are slowly injected. The needle is then removed, and a sterile pressure dressing and ice pack are placed at the injection site.