title: Fractures Due to Gunshot Wounds: Do Retained Bullet Fragments Affect Union?
abstract: BACKGROUND
  Many types of projectiles, including modern hollow point bullets, fragment into smaller pieces upon impact, particularly when striking bone. This study was performed to examine the effect on time to union with retained bullet material near a fracture site in cases of gunshot injury.
  
  
  METHODS
  All gunshot injuries operatively treated with internal fixation at a Level 1 Trauma Center between March 2008 and August 2011 were retrospectively reviewed. Retained bullet load near the fracture site was calculated based on percentage of material retained compared to the cortical diameter of the involved bone. Analyses were performed to assess the effect of the lead-cortical ratio and amount of comminution on time to fracture union.
  
  
  RESULTS
  Thirty-two patients (34 fractures) met the inclusion criteria, with an equal number of comminuted (17) and non-comminuted fractures (17). Seventeen of 34 fractures (50%) united within 4 months, 16/34 (47%) developed a delayed union, and 1/34 (3%) developed a nonunion requiring revision surgery. Sixteen of 17 fractures (94%) that united by 4 months had a cumulative amount of bullet fragmentation retained near the fracture site of less than 20% of the cortical diameter. Nine out of 10 fractures (90%) with retained fragments near the fracture site was equal to or exceeding 20% of the cortical diameter had delayed or nonunion. Fracture comminution had no effect on time to union.
  
  
  CONCLUSIONS
  The quantity of retained bullet material near the fracture site was more predictive of the rate of fracture union than was comminution. Fractures with bullet fragmentation equal to or exceeding 20% of the cortical width demonstrated a significantly higher rate of delayed union/nonunion compared to those fractures with less retained bullet material, which may indicate a local cytotoxic effect from lead on bone healing. These findings may influence decisions on timing of secondary surgeries.
  
  
  METHODS
  Level III.
authors.affiliation: Baptist Hospital and the Andrews Research and Education Institute , Pensacola, FL.
authors.forename: John T
authors.initials: JT
authors.lastname: Riehl
authors.affiliation: Orlando Regional Medical Center , Orlando, FL.
authors.forename: Keith
authors.initials: K
authors.lastname: Connolly
authors.affiliation: Orlando Regional Medical Center , Orlando, FL.
authors.forename: George
authors.initials: G
authors.lastname: Haidukewych
authors.affiliation: Orlando Regional Medical Center , Orlando, FL.
authors.forename: Ken
authors.initials: K
authors.lastname: Koval
mesh_terms: D001134:Arm Injuries / Q000209:etiology / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005547:Foreign Bodies; D044709:Forensic Ballistics; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000379:methods*; D017102:Fracture Healing / Q000502:physiology*; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D005599:Fractures, Ununited / Q000000981:diagnostic imaging* / Q000453:epidemiology; D006801:Humans; D007854:Lead / Q000009:adverse effects*; D007869:Leg Injuries / Q000209:etiology / Q000601:surgery; D008297:Male; D011859:Radiography; D012189:Retrospective Studies; D018570:Risk Assessment; D014193:Trauma Centers; D014948:Wounds, Gunshot / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*
chemical_list: D007854:Lead