title: What is the frequency of nerve injuries associated with acetabular fractures?
abstract: BACKGROUND
  Acetabular fractures and surgical interventions used to treat them can result in nerve injuries. To date, only small case studies have tried to explore the frequency of nerve injuries and their association with patient and treatment characteristics. High-quality data on the risk of traumatic and iatrogenic nerve lesions and their epidemiology in relation to different fracture types and surgical approaches are lacking.
  
  
  OBJECTIVE
  The purpose of this study was to determine (1) the proportion of patients who develop nerve injuries after acetabular fracture; (2) which fracture type(s) are associated with increased nerve injury risk; and (3) which surgical approach was associated with the highest proportion of patients developing nerve injuries using data from the German Pelvic Trauma Registry. Two secondary aims were (4) to assess hospital volume-nerve-injury relationship; and (5) internal data validity.
  
  
  METHODS
  Between March 2001 and June 2012, 2236 patients with acetabular fractures were entered into a prospectively maintained registry from 29 hospitals; of those, 2073 (92.7%) had complete records on the endpoints of interest in this retrospective study and were analyzed. The neurological status in these patients was captured at their admission and at the discharge. A total of 1395 of 2073 (67%) patients underwent surgery, and the proportions of intervention-related and other hospital-acquired nerve injuries were obtained. Overall proportions of patients developing nerve injuries, risk based on fracture type, and risk of surgical approach type were analyzed.
  
  
  RESULTS
  The proportion of patients being diagnosed with nerve injuries at hospital admission was 4% (76 of 2073) and at discharge 7% (134 or 2073). Patients with fractures of the "posterior wall" (relative risk [RR], 2.0; 95% confidence interval [CI], 1.4-2.8; p=0.001), "posterior column and posterior wall" (RR, 2.9; CI, 1.6-5.0; p=0.002), and "transverse+posterior wall" fracture (RR, 2.1; CI, 1.3-3.5; p=0.010) were more likely to have nerve injuries at hospital discharge. The proportion of patients with intervention-related nerve injuries and that of patients with other hospital-acquired nerve injuries was 2% (24 of 1395 and 46 of 2073, respectively). They both were associated with the Kocher-Langenbeck approach (RR, 3.0; CI, 1.4-6.2; p=0.006; and RR, 2.4; CI, 1.4-4.3; p=0.004, respectively).
  
  
  CONCLUSIONS
  Acetabular fractures with the involvement of posterior wall were most commonly accompanied with nerve injuries. The data suggest also that Kocher-Langenbeck approach to the pelvic ring is associated with a higher risk of perioperative nerve injuries. Trauma surgeons should be aware of common nerve injuries, particularly in posterior wall fractures. The results of the study should help provide patients with more exact information on the risk of perioperative nerve injuries in acetabular fractures.
  
  
  METHODS
  Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany, wlehmann@uke.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lehmann
authors.forename: Michael
authors.initials: M
authors.lastname: Hoffmann
authors.forename: Florian
authors.initials: F
authors.lastname: Fensky
authors.forename: Jakob
authors.initials: J
authors.lastname: Nüchtern
authors.forename: Lars
authors.initials: L
authors.lastname: Großterlinden
authors.forename: Emin
authors.initials: E
authors.lastname: Aghayev
authors.forename: Helmar
authors.initials: H
authors.lastname: Lehmann
authors.forename: Fabian
authors.initials: F
authors.lastname: Stuby
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Rueger
mesh_terms: D000077:Acetabulum / Q000293:injuries* / Q000601:surgery*; D015897:Comorbidity; D016001:Confidence Intervals; D019317:Evidence-Based Medicine; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects; D050723:Fractures, Bone / Q000145:classification / Q000453:epidemiology* / Q000601:surgery*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D059348:Peripheral Nerve Injuries / Q000453:epidemiology*; D015995:Prevalence; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment