title: Anatomical basis of the risk of radial nerve injury related to the technique of external fixation applied to the distal humerus.
abstract: OBJECTIVE
  Stabilization of humeral shaft and elbow fractures can be achieved with an external-fixator. Reports about nerve injuries associated with this procedure are rare in literature. Purpose of this anatomical study was to examine the relation of the radial nerve to distal humeral half pins.
  
  
  METHODS
  Percutaneous insertion of external-fixator half pins was performed in 20 upper limbs of 20 cadavers, according to established technique, laterally in the distal humerus.
  
  
  RESULTS
  Dissection of the upper limbs showed radial nerve injury in four of the 40 placed half pins. The proximal half pin impaled the nerve in one case and the distal half pin in three cases. Moreover the nerve was directly in contact with the pins in nine cases (five proximally, four distally).
  
  
  CONCLUSIONS
  Insertion of external-fixator half pins in the distal humerus can easily injure the radial nerve. Thus we advocate a larger skin incision, blunt dissection to the lateral cortex of the humerus and retraction of soft tissue during half pin insertion.
authors.affiliation: Department of Traumatology, Medical University of Graz, Auenbruggerplatz 7a, 8036, Graz, Austria.
authors.forename: Hans
authors.initials: H
authors.lastname: Clement
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Pichler
authors.forename: Norbert Peter
authors.initials: NP
authors.lastname: Tesch
authors.forename: Nima
authors.initials: N
authors.lastname: Heidari
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Grechenig
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails / Q000009:adverse effects*; D002102:Cadaver; D016267:External Fixators / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006811:Humerus / Q000033:anatomy & histology / Q000294:innervation*; D008297:Male; D008875:Middle Aged; D011826:Radial Nerve / Q000033:anatomy & histology* / Q000293:injuries*