Relationship of disc degeneration after pubertal growth spurt to future low back pain: a longitudinal cohort study.

ABSTRACT

PURPOSE: In this longitudinal cohort study, we investigated the relationship of disc degeneration (DD) after pubertal growth spurt to future low back pain (LBP). METHODS: A group of healthy volunteers underwent a semi-structured interview about LBP without trauma and a 1.5T lumbar MRI at ages 18 and 34. A Pfirrmann Summary Score (PSS) was calculated by adding up the Pfirrmann grades of the three lowest lumbar discs of each subject (range 3-15). The relationship of PSS at age 18 to LBP at age 34 was analyzed. RESULTS: Forty-one participants had full data at both time points. Mean PSS at age 18 was 6.8 (SD 1.1) and 5.6 (SD 1.2) for participants with or without LBP at age 34, respectively (p = 0.009). The OR (95% CI) of PSS at age 18 for LBP at age 34 was 5.46 (1.22 to 24.47) when adjusted for sex, BMI, smoking and physical activity. All participants but one with PSS greater than 6 at age 18 reported LBP at age 34. CONCLUSION: This is the first study to suggest that DD may be associated with future LBP and the critical time frame seems to be the pubertal growth spurt. Every 1-point increase in Pfirrmann grade at age 18 increased the risk of LBP 5.5-fold at age 34 when adjusted for sex, BMI, smoking and physical activity at age 34. All participants but one with at least one disc with Pfirrmann grade 3 or higher at age 18 reported LBP at age 34.