title: Radial nerve location at the posterior aspect of the humerus: an anatomic study of 100 specimens.
abstract: OBJECTIVE
  Radial neuropathy represents a devastating complication in a posterior approach to the distal humerus. This study aimed to propose "safe zones" regarding the radial nerve (RN) location at the posterior aspect of the humerus to minimize the risk of iatrogenic injury.
  
  
  METHODS
  In 100 embalmed specimens, the distances of the proximal edge of the olecranon fossa (OF) to the radial nerve at the medial edge (R1), at the center (R2) and at the lateral edge (R3) of the posterior aspect of humeral shaft were measured. Humeral length (HL) and transcondylar width (TW) were evaluated and correlated to R1, R2 and R3.
  
  
  RESULTS
  R1 was 15.0 (±2.1; 10.6-19.5) cm, R2 averaged 12.7 (±1.6; 8.9-15.7) cm, R3 was 10.6 (±1.3; 7.6-13.7) cm. HL was 30.8 (±1.9) cm. TW averaged 6.3 (±0.6) cm. TW and HL correlate with R1, R2, R3 (r = 0.451-0.565 [95% CI 0.279-0.685]). The mean ratio was 2.3 (±0.18) for HL/R1, 2.6 (±0.23) for HL/R2 and 3.1 (±0.31) for HL/R3. The ratio averaged 2.2 (±0.20) for R1/TW, 1.9 (±0.18) for R2/TW and 1.6 (±0.15) for R3/TW.
  
  
  CONCLUSIONS
  We present the OF as an osseous landmark to reduce the risk of iatrogenic radial neuropathy. HL and TW can be reliably used to estimate the RN location. The consistent "safe zones" of the RN in relation to the OF are 10.5 cm at the medial edge, 9 cm at the center and 7.5 cm at the lateral edge of the posterior aspect of the humeral shaft.
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany. michaelhackl@live.de.|Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany. michaelhackl@live.de.|Institute of Anatomy I, University of Cologne, Cologne, Germany. michaelhackl@live.de.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-6183-5621
authors.initials: M
authors.lastname: Hackl
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany.
authors.forename: Deborah
authors.initials: D
authors.lastname: Damerow
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany.|Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Leschinger
authors.affiliation: Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.|Institute of Anatomy II, University of Cologne, Cologne, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Scaal
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany.|Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Lars Peter
authors.initials: LP
authors.lastname: Müller
authors.affiliation: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany.|Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors.forename: Kilian
authors.initials: K
authors.lastname: Wegmann
mesh_terms: D000715:Anatomy; D006801:Humans; D006811:Humerus / Q000033:anatomy & histology* / Q000294:innervation*; D007049:Iatrogenic Disease / Q000517:prevention & control; D011826:Radial Nerve / Q000033:anatomy & histology*; D020425:Radial Neuropathy / Q000517:prevention & control
keywords: Anatomy; Fracture; Humerus; Olecranon fossa; Radial nerve; Radial neuropathy