title: Axillary nerve lesions after open reduction and internal fixation of proximal humeral fractures through an extended lateral deltoid-split approach: electrophysiological findings.
abstract: BACKGROUND
  Axillary nerve injuries after shoulder surgery are rare. In most studies, the frequency of injury is usually determined using clinical examinations, but results from intraoperative neuromonitoring studies have revealed higher than expected rates. Few studies have investigated this topic. Our aim was to determine the frequency of axillary nerve lesions after open reduction and internal fixation of proximal humeral fractures by using electrophysiological assessments and to provide a review of the relevant literature.
  
  
  METHODS
  This was a retrospective cohort study of 76 consecutive patients who received open reduction and internal fixation of a proximal humeral fracture using a locking plate through a deltoid-splitting approach. We performed a clinical and electrophysiological examination at a minimum follow-up time of 12 months. Functional results were assessed according to the Constant-Murley and Disabilities of the Arm, Shoulder and Hand scores. Electrophysiological examinations comprised electromyography, electroneurography, and motor and somatosensory evoked potentials. The main outcome was the frequency of axillary nerve lesions.
  
  
  RESULTS
  Forty patients were monitored for an average of 28 months. The mean raw Constant-Murley score was 61 points, the age- and gender-adjusted score was 71%, and the mean Disabilities of the Arm, Shoulder and Hand score was 33 points. Neurapraxia occurred in 1 patient, axonotmesis with incomplete reinnervation occurred in 3, and complete reinnervation occurred in 3. The latter group was classified as having a temporary axillary nerve lesion.
  
  
  CONCLUSIONS
  The 10% rate of permanent axillary nerve lesions in our cohort is higher than expected based on the clinical examination. Electrophysiological assessment is therefore more appropriate to detect axillary nerve injuries.
authors.affiliation: Department of Trauma Surgery, Orthopedics, and Hand Surgery, Klinikum Südstadt Rostock, Rostock, Germany. Electronic address: thomas.westphal@kliniksued-rostock.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Westphal
authors.affiliation: Facharztzentrum am Listbogen, Leipzig, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Woischnik
authors.affiliation: Gesellschaft für klinische und Versorgungsforschung mbH, Magdeburg, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Adolf
authors.affiliation: Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Feistner
authors.affiliation: Department of Trauma Surgery, Otto-von-Guericke University, Magdeburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Piatek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla / Q000294:innervation; D001860:Bone Plates; D001917:Brachial Plexus / Q000293:injuries* / Q000503:physiopathology; D015331:Cohort Studies; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D000070799:Open Fracture Reduction / Q000009:adverse effects*; D012189:Retrospective Studies; D012784:Shoulder Fractures / Q000601:surgery*
keywords: Electrophysiology; fracture fixation; internal; neurophysiology; peripheral nerve injuries; postoperative complications; shoulder fractures