Patellar Tendinopathy in Athletes : Current Diagnostic and Therapeutic Recommendations

To determine the accuracy of the use of sonography for differentiation of full- from partial-thickness tears or tendinosis of the Achilles tendon by using surgical findings as the standard of reference and to identify sonographic characteristics of full-thickness tears that can be used to differentiate the two types of tears. In part A of this study, sonographic findings (based on reports) in 26 consecutive cases of tears of the Achilles tendon were compared with surgical findings. In part B, the sonograms were blindly and retrospectively evaluated with respect to six sonographic characteristics possibly related to pathologic findings in the tendon, and the characteristics were correlated with surgical findings. In part A, statistical data regarding the use of sonographic findings to distinguish full- from partial-thickness tears were as follows: sensitivity, 100%; specificity, 83%; accuracy, 92%; positive predictive value, 88%; and negative predictive value, 100%. In part B, tendon thickness (P <.001), posterior acoustic shadowing (P =.007), and tendon retraction (P <.001) were correlated with full-thickness tears. Visualization of fat herniation (P =.051) and of the plantaris tendon (P =.098) demonstrated marginal correlation with full-thickness tears. Echogenicity at the site of the pathologic finding in the tendon showed no significant correlation. Sonography can be used to differentiate full- from partial-thickness tears or tendinosis of the Achilles tendon with 92% accuracy. Undetectable tendon at the site of injury, tendon retraction, and posterior acoustic shadowing demonstrate statistically significant correlation with full-thickness tears.

This study was conducted to illustrate and classify the abnormalities found on high-resolution MR imaging of symptomatic Achilles tendons in athletic adult patients. One hundred patients with 118 painful Achilles tendons were imaged with a 1.5-T magnet. The tendon, peritendinous tissues, tendon insertion, and musculotendinous junction were examined on MR imaging. Twenty-eight patients underwent surgery, and histopathologic samples were taken in 13. Long-term follow-up was performed, on average, 3.4 years after MR imaging. Of 118 painful Achilles tendons, abnormalities were detected in 111. These were in the tendon (n = 90), surrounding structures, or both. Fifty-four tendons had a focal area of increased intratendinous signal, best detected on axial high-resolution T1-weighted gradient-echo MR imaging. Histopathology confirmed abnormal tendon structure. Of the 21 surgically proven foci of tendinosis, 20 were revealed on MR imaging. At the level of the insertion, changes were found in the tendon in 15%, in the retrocalcaneal bursa in 19%, and in the calcaneal bone marrow in 8% of the studies. Abnormalities in peritendinous soft tissues were detected in 67%. More than one type of abnormality was found in 64% of the studies. Lesions in the Achilles tendon and in the peritendinous structures can have similar clinical presentation. MR imaging detects and characterizes these changes. A more specific diagnosis and prognosis can be made with the use of MR imaging than with clinical examination alone.