Relationship between spinopelvic parameters and chronic neck, back and multiregional pain

Abstract

Introduction: Sagittal balance plays an important role in the transmission of shearing and compressive forces through the anterior and posterior vertebral column. Abnormal sagittal alignment may alter normal load transmission and spinal mobility, which leads to disc degeneration and spinal pain. The pain can be localized in the neck and back, or it can be multiregional in some cases. Several studies have focused on the sagittal and spinopelvic parameters in different conditions, but information on how these parameters vary in individuals with different regions of spinal pain is still limited. As such, this study aims to assess the spinopelvic parameters in patients with neck, back and multiregional (neck and back) pain, and its association with structural changes of the lumbar spine. Methods: 118 Southern Chinese subjects were recruited from the Hong Kong Neck/Low Back Pain Cohort (62% females; mean age: 53.4 years). Only those subjects with complete clinical profile, no history of trauma and no visible structural spine deformity, such as scoliosis and spondylolisthesis were included. Standing lateral full-length radiographs were achieved for all patients. The sagittal vertical axis (SVA), Global tilt angle (GTA), T1-pelvic angle (T1PA), T1 sagittal tilt (T1ST), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were assessed. The lumbar lordosis index was also calculated (LLI=LL/PI). Radiographs were also used to assess lumbar discs for the presence or absence of disc space narrowing and osteophytes. Scores were assigned to each subject on the basis of presence or absence of disc space narrowing from 0-5 for each five lumbar segments and 0-10 for the osteophytes on each endplate of five lumbar segments. Subject demographics including body mass index (BMI) was also obtained. Data was analyzed using One-way ANOVA and regression analysis. Results: Intra-rator reliability for all measurements was found to be excellent. There were 24% patients with neck pain, 56% with back pain and 20% reported both neck and low back pain. No significant differences were observed between age, BMI, scores of lumbar disc space narrowing and osteophytes among the three groups. SVA was significantly higher in patients with only back pain (p=0.01) while T1ST and LL were significantly lower in these patients (p=0.01 & p=0.01). Subjects with multiregional pain did not show any significant difference with any of the parameters. Significant association was observed between osteophyte scores and age (r=0.35, p<0.001), BMI (r=0.21, p=0.003), LL (r=-0.18, p=0.03) and LLI (r=-0.24, p=0.003). Disc space narrowing showed significant association with BMI (r=0.17, P=0.03), PI (r=-0.21, p=0.001) & SS (r=-0.23, p=0.006). Discussion: The results of the study reveal that the main markers of overall sagittal balance (SVA and T1ST) are closely associated with low back pain as compared to neck or multiregional pain. Any deviation in the sagittal balance tends to have a stronger link with those lumbar spine segment changes that can lead to back pain. Structural changes such as osteophytes and disc space narrowing seen in these chronic pain subjects are linked with PI, LL and SS, but this relationship requires further study.