title: Peroneal nerve: Normal anatomy and pathologic findings on routine MRI of the knee.
abstract: BACKGROUND
  Peroneal nerve lesions are not common and are often exclusively assessed clinically and electromyographically.
  
  
  METHODS
  On a routine MR examination without dedicated MR-neurography sequences the peroneal nerve can readily be assessed. Axial T1-weighted sequences are especially helpful as they allow a good differentiation between the nerve and the surrounding fat.
  
  
  RESULTS
  The purpose of this article is to review the normal anatomy and pathologic conditions of the peroneal nerve around the knee.
  
  
  CONCLUSIONS
  In the first part the variable anatomy of the peroneal nerve around the knee will be emphasized, followed by a discussion of the clinical findings of peroneal neuropathy and general MR signs of denervation. Six anatomical features may predispose to peroneal neuropathy: paucity of epineural tissue, biceps femoris tunnel, bifurcation level, superficial course around the fibula, fibular tunnel and finally the additional nerve branches. In the second part we discuss the different pathologic conditions: accidental and surgical trauma, and intraneural and extraneural compressive lesions.
  
  
  CONCLUSIONS
  • Six anatomical features contribute to the vulnerability of the peroneal nerve around the knee. • MR signs of muscle denervation within the anterior compartment are important secondary signs for evaluation of the peroneal nerve. • The most common lesions of the peroneal nerve are traumatic or compressive. • Intraneural ganglia originate from the proximal tibiofibular joint. • Axial T1-weighted images are the best sequence to visualise the peroneal nerve on routine MRI.
authors.affiliation: Department of Radiology, AZ Sint-Maarten Duffel-Mechelen, campus Duffel, Rooienberg 25, 2570, Duffel, Belgium.
authors.forename: F R A
authors.initials: FR
authors.lastname: Van den Bergh
authors.forename: F M
authors.initials: FM
authors.lastname: Vanhoenacker
authors.forename: E
authors.initials: E
authors.lastname: De Smet
authors.forename: W
authors.initials: W
authors.lastname: Huysse
authors.forename: K L
authors.initials: KL
authors.lastname: Verstraete