Prevalence and distribution of intervertebral disc degeneration over the entire spine in a population-based cohort: the Wakayama Spine Study.
OBJECTIVE
The purposes of this study were to investigate the prevalence and distribution of intervertebral disc degeneration (DD) over the entire spine using magnetic resonance imaging (MRI), and to examine the factors and symptoms potentially associated with DD.


METHODS
This study included 975 participants (324 men, mean age of 67.2 years; 651 women, mean age of 66.0 years) with an age range of 21-97 years in the Wakayama Spine Study. DD on MRI was classified into Pfirrmann's system (grades 4 and 5 indicating DD). We assessed the prevalence of DD at each level in the cervical, thoracic, and lumbar regions and the entire spine, and examined DD-associated factors and symptoms.


RESULTS
The prevalence of DD over the entire spine was 71% in men and 77% in women aged <50 years, and >90% in both men and women aged >50 years. The prevalence of an intervertebral space with DD was highest at C5/6 (men: 51.5%, women: 46%), T6/7 (men: 32.4%, women: 37.7%), and L4/5 (men: 69.1%, women: 75.8%). Age and obesity were associated with the presence of DD in all regions. Low back pain was associated with the presence of DD in the lumbar region.


CONCLUSIONS
The current study established the baseline data of DD over the entire spine in a large population of elderly individuals. These data provide the foundation for elucidating the causes and mechanisms of DD.
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
M
M
Teraguchi
Department of Joint Disease Research, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
N
N
Yoshimura
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan. Electronic address: hashizum@wakayama-med.ac.jp.
H
H
Hashizume
Department of Clinical Motor System Medicine, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
S
S
Muraki
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
H
H
Yamada
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
A
A
Minamide
Department of Joint Disease Research, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
H
H
Oka
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
Y
Y
Ishimoto
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
K
K
Nagata
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
R
R
Kagotani
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
N
N
Takiguchi
Department of Clinical Motor System Medicine, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
T
T
Akune
Department of Sensory & Motor System Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
H
H
Kawaguchi
Rehabilitation Services Bureau, National Rehabilitation Center for Persons with Disabilities, Saitama, Japan.
K
K
Nakamura
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
M
M
Yoshida
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002574:Cervical Vertebrae / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D007564:Japan / Q000453:epidemiology; D017116:Low Back Pain / Q000453:epidemiology / Q000209:etiology; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology; D015995:Prevalence; D012720:Severity of Illness Index; D017678:Sex Distribution; D013904:Thoracic Vertebrae / Q000473:pathology; D055815:Young Adult
Distribution; Entire spine; Intervertebral disc degeneration; Magnetic resonance imaging; Population-based cohort; Prevalence