MR imaging appearance of the extensor mechanism of the knee: functional anatomy and injury patterns.

A. H. Sonin*, S. W. Fitzgerald, M. E. Bresler, M. D. Kirsch, F. L. Hoff, H. Friedman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

58 Scopus citations


Trauma to the extensor mechanism of the knee, a common clinical problem, can be accurately evaluated with magnetic resonance (MR) imaging. The extensor mechanism consists of the quadriceps muscle and tendon, patella, patellar tendon, and patellar retinacula. Injuries of these structures can be classified into partial and complete tears. Acute injuries are associated with edema, hemorrhage, and fluid collections; chronic injuries often demonstrate redundancy, atrophy, and retraction of the affected structures. MR imaging is useful in differentiating partial and complete tears and in evaluating tissue edema and hemorrhage. It also allows detection of unsuspected nondisplaced patellar fractures and chronic conditions due to repetitive trauma. Transient dislocation of the patella is an often clinically unsuspected entity for which MR imaging can serve an important diagnostic role. A detailed understanding of the functional and anatomic relationships of the extensor mechanism can greatly assist in interpretation of MR images of the traumatized knee.

Original languageEnglish (US)
Pages (from-to)367-382
Number of pages16
JournalRadiographics : a review publication of the Radiological Society of North America, Inc
Issue number2
StatePublished - Mar 1995

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'MR imaging appearance of the extensor mechanism of the knee: functional anatomy and injury patterns.'. Together they form a unique fingerprint.

Cite this