Joint laxity negatively correlates with lumbar disc degeneration in young adults

STUDY DESIGN.: Cross-sectional study of preselected cohort of patients with neck pain. OBJECTIVE.: To determine the association between joint laxity and lumbar disc degeneration in young adults. SUMMARY OF BACKGROUND DATA.: Joint laxity is known to be closely related with orthopedic injuries and disease; however, studies about the relationship between spinal disorder and joint laxity are lacking. METHODS.: Patients aged 30 to 40 years, seen at the outpatient clinic of our hospital for the evaluation of neck pain, who had magnetic resonance imaging of the cervical spine with routine inclusion of T2-weighted sagittal plane of the whole spine were included in the study. The Beighton and Horan criteria was used for the assessment of joint laxity. Logistic regression analysis was performed to estimate the odds ratio for lumbar disc degeneration in patients with joint laxity, and other variables including age, sex, body mass index, physical workload, neck pain (visual analogue scale score), and related disability (neck disability index score), and sagittal alignment. RESULTS.: A total of 101 patients were enrolled in the study: 34 patients with joint laxity and 67 patients without joint laxity. There were no differences in age, body mass index, physical workload, neck pain (visual analogue scale score), and neck disability index score between the 2 groups, but there was a significant difference in sex ratio (P < 0.001). Patients with joint laxity showed increased lumbar lordosis (P = 0.004) and increased sacral slope (P = 0.003) but without significant difference in pelvic incidence (P = 0.084). In univariate analysis, presence of joint laxity (Beighton score ≥4) as well as positive results of thumb (P = 0.016) and elbow (P = 0.047) tests were significantly associated with decreased risk for lumbar disc degeneration. Presence of joint laxity remained significant after multivariate adjustment for sex and lumbar lordosis (odds ratio = 0.373, P = 0.040). CONCLUSION.: Increased joint laxity was closely associated with lower prevalence of lumbar disc degeneration in young adults, and the increased lumbar lordosis associated with joint laxity might explain the decreased risk of lumbar disc degeneration.