title: Is Preexisting Cervical Disk Degeneration a Prognostic Factor in Whiplash-associated Disorders?
abstract: METHODS
  This is a retrospective control study.
  
  
  OBJECTIVE
  We aimed to determine whether preexisting cervical disk degeneration is a prognostic factor in Whiplash-associated disorder (WAD).
  
  
  BACKGROUND
  WAD is a common injury of traffic accident and has a broad range of prognoses. Although numerous studies have investigated prognostic factors in WAD, few have evaluated the effect of preexisting disk degeneration.
  
  
  METHODS
  This study involved 45 consecutive patients with grade I or II WAD having advanced disk degeneration (at least 1 disk of Miyazaki grade≥III on magnetic resonance imaging) and a control cohort of 52 patients with no or mild disk degeneration (all disks having Miyazaki grades≤II). Clinical assessment included pain severity (assessed by the visual analog scale), neck pain-related disability (assessed by the neck disability index), and physical and mental health condition [assessed by the short-form 36 (SF-36) physical composite score and SF-36 mental composite score, respectively]. Changes in each parameter were evaluated at baseline and at 3-month, 6-month, and 1-year follow-ups and compared between the 2 groups.
  
  
  RESULTS
  There were no differences between the 2 groups regarding demographics and baseline outcome parameters (all P>0.05). There were also no differences in improvement in visual analog scale for neck pain, neck disability index, SF-36 physical composite score, or SF-36 mental composite score between the 2 groups (all P>0.05) for each visit. The number of claim closures was significantly lower among patients with advanced degeneration than among controls at 6-month and 1-year follow-ups (P=0.004 and 0.006, respectively).
  
  
  CONCLUSIONS
  In the present study, the clinical presentation and prognosis of WAD were not affected by preexisting disk degeneration. However, claim closure was delayed in patients with preexisting disk degeneration. These results suggest that misunderstanding of disk degeneration on magnetic resonance imaging may create persistent illness and lead to continued compensation in WAD.
authors.affiliation: Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Nam-Su
authors.initials: NS
authors.lastname: Chung
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Jeon
authors.forename: Yu-Sang
authors.initials: YS
authors.lastname: Lee
authors.forename: Jang-Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Han-Dong
authors.initials: HD
authors.lastname: Lee
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000150:complications* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D014911:Whiplash Injuries / Q000150:complications* / Q000000981:diagnostic imaging