Acute partial or complete rupture of the posterior tibial tendon in young, athletic individuals is less common then chronic injury and is usually seen at the insertion of the tendon on the navicular bone. Chronic posterior tibial tendon rupture typically develops in women during the 5th and 6th decades of life and is associated with progressive flat foot deformity. The tear is commonly noted behind the medial malleolus, where the tendon is subjected to a significant amount of friction.
Surgical and MR imaging classification of chronic posterior tibial tendon ruptures divides these injuries into three types:
Type I tear consists of an incomplete tear with fusiform enlargement, intrasubstance degeneration, and longitudinal splits.
Type II tear represents further stretching and elongation of the tendon. On axial images, a decrease in the diameter of the tendon.
Type III tear represents complete disruption of the tendon fibers.
Ax PD Fat Sat
Sag STIR
Ax PD Fat Sat
Sag STIR
Ax PD Fat Sat
16 yo M pain and swelling of the R ankle and foot. Patient has history of repair of the posterior tibialis tendon rupture.
The posterior tibial tendon arises from the posterior tibial muscle within the deep posterior compartment of the calf and courses behind the medial malleolus in a fibroosseous groove. The tendon then turns anteriorly and inserts primarily on the navicular bone. Other sites of insertion include the cuneiform bones, second through fourth metatarsal bases, sustentaculum talus, and cuboid.
There are many factors implicated as a cause of posterior tibial tendon tear: impingement at the fibroosseous groove, constriction by the overlying flexor retinaculum, an accessory navicular bone weakening the insertion, hypovascularity of the tendon at the medial malleolus, inflammatory arthropathies, acute trauma, corticosteroid injection, and chronic mechanical overload.
Acute partial or complete rupture of the posterior tibial tendon in young, athletic individuals is less common then chronic injury and is usually seen at the insertion of the tendon on the navicular bone. Chronic posterior tibial tendon rupture typically develops in women during the 5th and 6th decades of life and is associated with progressive flat foot deformity. The tear is commonly noted behind the medial malleolus, where the tendon is subjected to a significant amount of friction.
Surgical and MR imaging classification of chronic posterior tibial tendon ruptures divides these injuries into three types:
Type I tear consists of an incomplete tear with fusiform enlargement, intrasubstance degeneration, and longitudinal splits. On axial MR images, the diameter of the tendon may be five to 10 times that of the adjacent flexor digitorum longus tendon. High-signal-intensity foci representing longitudinal splits are noted within the substance of the tendon on T1-weighted and proton-density-weighted images. Thus, diagnostic overlap exists between severe tendinosis and partial type I tears because both demonstrate fusiform thickening of the tendon with intrasubstance signal intensity alteration.
Type II tear represents further stretching and elongation of the tendon. On axial images, a decrease in the diameter of the tendon, usually without signal intensity alterations, is diagnostic for this pathologic condition. The caliber of the tendon may now be equal to or less than that of the adjacent flexor digitorum longus tendon.
Type III tear represents complete disruption of the tendon fibers. These are quite rare and appear at MR imaging as tendon discontinuity. The gap may be filled with fluid or granulation tissue, depending on the chronicity of the injury.
Our images demonstrate complete tear of the posterior tibials tendon which was previously repaired. Proximal fragment is retracted barely seen 5 cm superior and posterior to medial maleollus
Suggested reading:
M. E. Schweitzer and D. Karasick. MR Imaging of Disorders of the Posterior Tibialis Tendon. Am. J. Roentgenol., September 1, 2000; 175(3): 627 - 635.
Z. S. Rosenberg, J. Beltran, and J. T. Bencardino. MR Imaging of the Ankle and Foot. RadioGraphics, October 1, 2000; 20(90001): 153S - 179.
Balen PF and Helms CA. Association of Posterior Tibial Tendon Injury with Spring Ligament Injury, Sinus Tarsi Abnormality, and Plantar Fasciitis on MR Imaging. AJR 2001; 176:1137-1143.
M. P. Recht and B. G. Donley. Magnetic Resonance Imaging of the Foot and Ankle.
J. Am. Acad. Ortho. Surg., May 1, 2001; 9(3): 187 - 199.
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