Cross-sectional observational study on the relationship between the degrees of disc degeneration and sagittal alignment in asymptomatic healthy individuals.
This study sought to determine whether the sagittal spine alignment subtype is related to the prevalence of lumbar disc degeneration.
Sagittal balance and spinopelvic parameters might be risk factors for disc degeneration.
A total of 70 asymptomatic participants (36 women and 34 men) without regular physical activity were categorized according to the four subtypes of sagittal alignment proposed by Roussouly. All participants underwent magnetic resonance imaging of the lumbar spine (1.5T) and panoramic radiography of the spine. The degree of disc degeneration was graded using T2-weighted images according to the Pfirrmann classification. Spinopelvic parameters and vertebral curvatures were measured on digital panoramic radiographs using Surgimap software. Interobserver analyses for the Pfirrmann classification and spinopelvic parameters were assessed using the weighted Kappa and intraclass correlation coefficient (ICC), respectively.
The Kappa associated with disc degeneration classification was 0.79 (95% confidence intervals 0.72–0.87). The ICCs were excellent, with small confidence intervals for all spinopelvic parameters. The type II group (flat lordosis) showed a higher frequency of degenerated discs at L4-L5 (P = 0.03) than the type IV group (long and curved lumbar spine). No significant differences in disc degeneration were observed among the four subtypes at the other disc levels. We found a negative, moderate correlation between the spinopelvic parameters and the occurrence of disc degeneration in the type II group.
The Roussouly subtype II sagittal alignment is significantly associated with disc degeneration at L4-L5 in asymptomatic young adults. Our results support the hypothesis that spinal sagittal alignment plays a role in early disc degeneration.
Level of Evidence: 3
*Division of Radiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
†Department of Biomechanics, Medicine, and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Address correspondence and reprint requests to Rafael Menezes-Reis, MSc, Radiology Division, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, Brazil 14049-090; E-mail: firstname.lastname@example.org
Received 21 August, 2015
Revised 10 December, 2015
Accepted 16 February, 2016
The manuscript submitted does not contain information about medical device(s)/drug(s).
CAPES and CNPq grant funds were received in support of this work.
Relevant financial activities outside the submitted work: grants, employment, and payment for manuscript preparation.