Patellar Tendinopathy

Quadriceps tendinopathy is far less conunon than patellar tendinopathy and usually relates to sporting activities or strenuous exercise. Clinically, this condition is characterized by focal pain over the distal portion of the tendon, exacerbated by resisted extension of the knee or firm pressure over it. The skin is normal and there is no evidence of intra-articular effusion at physical examination. Similar to other tendinopathies, the involvement of the quadriceps tendon mainly relates to degeneration and fibro-myxoid changes. In this setting, the main value of... 

Patellar tendinopathy involving the tendon diffusely is, for the most part, unrelated to sporting activities and may be observed in patients with... 

Fig. 14.55. Jumper s knee. Proximal patellar tendinopathy. a Long-axis 12-5 MHz US image of the proximal patellar tendon (arrows) shows a ill-defined hypoechoic area (asterisks) located at the level of the middle and posterior tendon thirds reflecting degenerative tendinopathy. Note the absence of significant tendon thickening and the normal fibrillar appearance of the most superficial fibers (arrowhead). Hfp, Hoffa fat pad...

Lian et al. 1996 Cook et al. 2001). On the other hand, US signs of patellar tendinopathy in asymptomatic sportsmen have been associated with a higher risk of developing symptomatic jumper s knee in the future (Fredberg and Bolvig 2002). 

Fig. 14.58a,b. Spectrum of patellar tendinopathies. Two different patients, a Longitudinal extended field-of-view 12-5 MHz US image reveals a diffusely thickened and heterogeneous hypoechoic patellar tendon (arrows) reflecting diffuse tendinopathy. b Longitudinal extended field-of-view 12-5 MHz US image demonstrates selective thickening (arrows) of the distal third of the patellar tendon as an expression of distal tendinopathy. The proximal portion of the tendon (arrowheads) retains a normal appearance... 

Fig. 14.59a,b. Postsurgical appearance of the patellar tendon, a Long- and b short-axis 12-5 MHz US images of the patellar tendon in a patient who underwent surgical treatment for jumper s knee reveal an overall tendon appearance similar to that of diffuse patellar tendinopathy (arrows). Note the postoperative thickening of the anterior soft-tissues (asterisks) and an in-trasuhstance fissuration (arrowhead). P, patella... 

Distal patellar tendinopathy is often associated with deep infrapatellar bursitis. Bursitis can result from local blunt trauma or may be secondary to microtrauma. US reveals a swollen and hypoechoic distal tendon associated or not with fluid distension of the infrapatellar bursa, which is a synovial structure located between the posterior tendon surface and the tibial cortex (Fig. 14.63). It must be noted that a minimal amount of bursal fluid can be detected with US in normal states, particularly if high-fre-... 

Fig. 14.28). Somewhat similar to the situation with the supraspinatus tendon, the examiner should be aware that the actual site of insertion is indicated by the prominence of the tuberosity and not by the anterior aspect of the tibial epiphysis. Short-axis US images of the patellar tendon are essential because the involvement by tendinopathy may occur out of the midline and possibly limited to the external borders of the tendon (Fig. 14.30). These planes depict a flattened tendon, shaped like a rectangle. In addition, they allow assessment of the medial and lateral patellar retinacula as sheet-like fibrous expansions attached on each side of the tendon (Fig. 14.30). Calcifications and ossification of the distal portion of the tendon can be encountered in asymptomatic subjects and are usually related to consequences of Osgood-Schlatter disease. 

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