IMAGING OF TENDONS - ADAPTATION, DEGENERATION, RUPTURE

Tendon imaging is mainly performed with ultrasonography (US) and magne tic resonance imaging (MRI) and has been improved within the last year s because of technical advancements and a better understanding of tend on pathology. Several concepts concerning the etiology and the course of tendon diseases have influenced image interpretation and vice versa . Adaptive mechanisms within the tendon tissue against stress can be o bserved mainly on histologic specimens and not macroscopically or with in-vivo imaging. Degeneration may occur in the form of tendinitis, pe ritendinitis, enthesitis, or myotendinal junction abnormality. Distinc t imaging findings exist for most of these forms. Many concepts that h ave been developed to explain tendon degeneration have been applied on virtually all tendons in the human body. They can be grouped into tho se which focus on hypovascularization, on biomechanical overload, and on degeneration secondary to other underlying disease. Tendon rupture seems, in many cases, to be the final stage of tendinitis. From this p oint of view, imaging may be used to predict the risk of tendon ruptur e together with other intrinsic and with extrinsic parameters. These c onsiderations result in the concept of the 'vulnerable zone' and of th e 'critical phase' in which tendon ruptures may predominantly occur. ( C) 1997 Elsevier Science Ireland Ltd.