title: Limitation of previous Allen classification and subaxial cervical spine injury classification (SLIC) system in distractive-extension injury of cervical spine: proposal of modified classification system.
abstract: OBJECTIVE
  To verify the clinical applicability of a modified classification system in distractive-extension cervical spine injury that reflects the degrees of soft tissue damage and spinal cord injury while complementing previous Allen classification and subaxial cervical spine injury classification (SLIC) system.
  
  
  METHODS
  A total of 195 patients with cervical spine distraction-extension (DE) injury were retrospectively classified. We added stages IIIA (with concomitant spinal cord injury without bony abnormalities) and IIIB (with concomitant additional soft tissue swelling) to the existing stages I and II of the Allen classification. We also supplemented the SLIC system by refining and assigning scores to bony morphology and soft tissue damage. The previous and proposed classification systems were compared by analyzing their scoring performances in terms of clinical features and prognosis.
  
  
  RESULTS
  The Allen classification yielded 153 and 42 patients with stage 1 and 42 stage 2 injuries, respectively. Patients classified according to the proposed system were stratified as follows: stage I, 58; stage II, 27; stage IIIA, 33; and stage IIIB, 77. Regarding neurological symptoms and prognosis, stages IIIA and IIIB were poorer than stage I but significantly better than stage II (P < 0.05). On the SLIC system, 146 patients scored ≥5; and 37 and 12 patients scored 4 and ≤3 points, respectively, whereas the numbers of patients who scored ≥5, 4, and ≤3 points on the modified SLIC system were 170, 21, and 4, respectively.
  
  
  CONCLUSIONS
  The proposed classification and scoring system to complement the Allen classification and SLIC system with respect to the degrees of soft tissue damage and spinal cord injury is considered effective for diagnosing and determining therapeutic directions and prognosis in cases of cervical spine extension injury.
authors.affiliation: Department of Orthopaedic Surgery, Research Institute of Clinical Medicine, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Republic of Korea.
authors.forename: Kyung-Jin
authors.initials: KJ
authors.lastname: Song
authors.affiliation: Department of Orthopaedic Surgery, Research Institute of Clinical Medicine, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Republic of Korea.
authors.forename: Su-Kyung
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Research Institute of Clinical Medicine, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Republic of Korea.
authors.forename: Dong-Hun
authors.initials: DH
authors.lastname: Ham
authors.affiliation: Department of Orthopaedic Surgery, Research Institute of Clinical Medicine, Biomedical Research Institute of Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Republic of Korea.
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Inje University, Haeundae Paik Hospital, 1435, Jwa-dong, Haeundae-gu, Busan, 612-030, Republic of Korea. alla1013@naver.com.
authors.forename: Byung-Wan
authors.initials: BW
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000293:injuries*; D004487:Edema / Q000145:classification; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D017695:Soft Tissue Injuries / Q000145:classification; D013124:Spinal Injuries / Q000145:classification*; D055815:Young Adult
keywords: Allen classification; Cervical spine; Distraction–extension injury; SLIC system; Soft tissue damage