title: The Use of T1 Sagittal Angle in Predicting Cervical Disc Degeneration.
abstract: METHODS
  Retrospective evaluation.
  
  
  OBJECTIVE
  To analyze the effect of T1 slope on degree of degeneration in patients with cervical disc degeneration.
  
  
  BACKGROUND
  The T1 slope is well known parameter that may be very useful in evaluating sagittal balance. There are no reports on the analysis of the relationship between T1 slope and cervical disc degeneration. We hypothesized that T1 slope has an effect on the degree of cervical degeneration.
  
  
  METHODS
  Sixty patients who had cervical spine magnetic resonance imaging (MRI) in our orthopedic clinic were enrolled. Patients were divided into two groups according to T1 slope. Radiologic parameters obtained from radiography and cervical spine MRI were compared between low T1 slope group (≤25) and high T1 slope group (>25).
  
  
  RESULTS
  Among low T1 slope group, average degeneration grade of each cervical segment was 2.65 in C2-3, 2.50 in C3-4, 2.62 in C4-5, 3.23 in C5-6, and 2.81 in C6-7. And that of high T1 group was 2.35 in C2-3, 2.32 in C3-4, 2.59 in C4-5, 2.79 in C5-6, and 2.32 in C6-7. Grade of degeneration of low T1 group was significantly higher, as compared with high T1 group in C5-6 (p=0.028) and C6-7 (p=0.009). Percentage of high grade degeneration of more than grand III was 65.4% in low T1 group and 32.4% in high T1 group (p=0.018). Risk of high grade degeneration of C6-7 was significantly higher in low T1 group (odds ratio, 5.63; 95% confidence interval, 1.665-19.057; p=0.005).
  
  
  CONCLUSIONS
  Patients with low T1 slope had higher grade of degeneration regardless of age and gender. Low T1 slope is a potential risk factor of cervical spondylosis especially in the C6-7 cervical segment.
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Bong-Seok
authors.initials: BS
authors.lastname: Yang
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Su-Keon
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Kyung-Sub
authors.initials: KS
authors.lastname: Song
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Sang-Pil
authors.initials: SP
authors.lastname: Yoon
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Geun
authors.initials: G
authors.lastname: Jang
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Chae-Chul
authors.initials: CC
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seong-Hwan
authors.initials: SH
authors.lastname: Moon
authors.affiliation: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hwan-Mo
authors.initials: HM
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
keywords: Cervical spine; Intervertebral disc degeneration; Magnetic resonance imaging; T1 slope