title: [Influence of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum].
abstract: OBJECTIVE
  To retrospectively explore the influences of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum (TOLF) and preliminarily detect its possible causes.
  
  
  METHODS
  A total of 94 TOLF patients were divided into two groups according to the absence or presence of minor back trauma: MT (minor trauma, n = 16) and NT (no trauma, n = 78). They were compared in terms of gender, age, duration of symptoms, levels of involvement, numbers of involved segments, ratio of intramedullary signal changes (IMSC), pre- & post-operative JOA (Japanese Orthopedic Association) score, recovery rate (RR) at the final follow-up. Multiple regression analysis was employed to elucidate the causes related with the surgical outcomes. The MT group was further divided into two subgroups according to the intervals between trauma and surgery to clarify the influences of surgical timing on the efficacies.
  
  
  RESULTS
  The JOA scores were 4.0 ± 1.4 and 8.4 ± 1.7 respectively in MT and NT groups at the final follow-up. The neurological status of patients improved in both groups (MT: P = 0.009, NT: P = 0.000). The patients were younger in MT groups (50 ± 11 years) than those in NT groups (58 ± 8 years) (P = 0.046). The ratio of IMSC was higher in MT groups (75.0%) than that in NT groups (25.6%) (P = 0.000). The pre- & post-operative JOA scores were lower in MT groups than those in NT groups (both P = 0.000). Multiple regression analysis revealed that the postoperative JOA score at the final follow-up was positively related with the preoperative JOA score (r = 0.60, P = 0.000) and negatively with trauma and IMSC (r = -1.82 and r = -1.87, P = 0.000) while the final postoperative RR were negatively related with trauma and IMSC (r = -26.26 and r = -33.70, P = 0.000). The surgical timing after trauma did not influence the efficacies (P = 0.147).
  
  
  CONCLUSIONS
  The TOLF patients with minor back trauma have a worse post-operative recovery. A minor trauma might be a risk factor of adverse surgical outcomes.
authors.affiliation: Department of Spinal Surgery, Second Hospital, Shandong University, Jinan 250033, China.
authors.forename: Dong-jin
authors.initials: DJ
authors.lastname: Wu
authors.forename: Zhen-song
authors.initials: ZS
authors.lastname: Jiang
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Sun
authors.forename: Xiu-wen
authors.initials: XW
authors.lastname: Wang
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiao
authors.forename: Da-chuan
authors.initials: DC
authors.lastname: Wang
authors.forename: Sheng-zhong
authors.initials: SZ
authors.lastname: Ma
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Chun-zheng
authors.initials: CZ
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D017843:Ligamentum Flavum / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000601:surgery*; D011379:Prognosis; D012189:Retrospective Studies; D013904:Thoracic Vertebrae; D016896:Treatment Outcome; D014947:Wounds and Injuries