title: Conservative and Operative Treatment in Extension Teardrop Fractures of the Axis.
abstract: METHODS
  A retrospective case series describing teardrop fracture of the axis.
  
  
  OBJECTIVE
  The purpose of the study was to clarify the clinical features, the mechanism of injury, and the potential instability of extension teardrop fractures of the axis, so as to emphasize the importance of recognizing this injury as a separate entity.
  
  
  BACKGROUND
  Teardrop fractures of the axis are rare spinal fractures, comprising only a small percentage of all injuries of the cervical spine. The stability of this fracture pattern has been a matter of debate leading to controversy regarding treatment strategies and the need for stabilization.
  
  
  METHODS
  We retrospectively reviewed data collected from 16 patients to document the mechanism of injury, neurological deficit, treatment and clinical outcome, and imaging findings.
  
  
  RESULTS
  Extension teardrop fractures accounted for approximately 8.9% of the upper cervical spinal injuries and 12.7% of axis fractures at the authors' institution over the same period. Six patients (4 males and 2 females) underwent surgery (4 by an anterior approach, 2 by a posterior approach). Ten cases underwent Halo-vest immobilization for a period between 6 and 12 weeks. At final follow-up, 14 cases achieved excellent results, whereas 2 patients complained of mild residual neck pain. Maximum cranial-caudal dimensions of the fragments were between 5 and 24 mm (average, 12.9 mm), and the transverse dimensions were between 5 and 22 mm (average, 11.1 mm). Fragment displacement ranged from 1 to 9 mm (average, 3.5 mm), whereas fragment rotation ranged from 10 to 52 degrees (average, 24.4 degrees) in the sagittal plane.
  
  
  CONCLUSIONS
  Most patients with an extension teardrop fracture of the axis can be treated conservatively. On the basis of this case series, the authors suggest that large fragment size, displacement or angulation, intervertebral disk injury, neurologic deficit, or signs of instability are reasonable indications for surgical treatment.
authors: *Department of Spinal Surgery, Ningbo No. 6 Hospital, NingBo, People's Republic of China†Department of Orthopaedic Surgery, Thomas Jefferson University & Rothman Institute, Philadelphia, PA.
authors: Yong
authors: Y
authors: Hu
authors: Christopher K
authors: CK
authors: Kepler
authors: Todd J
authors: TJ
authors: Albert
authors: Shannon
authors: S
authors: Hann
authors: Wei-Hu
authors: WH
authors: Ma
authors: Zhen-Shan
authors: ZS
authors: Yuan
authors: Wei-Xin
authors: WX
authors: Dong
authors: Rong-Ming
authors: RM
authors: Xu
mesh_terms: D000328:Adult; D000368:Aged; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging / Q000293:injuries*; D005260:Female; D005593:Fracture Fixation, Internal; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011859:Radiography; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult