Impact of joint hypermobility on lumbar positional changes in back pain patients: a cross-sectional weight-bearing MRI study

Purpose: To investigate positional lumbar changes by weight-bearing MRI in low back pain (LBP) patients with hypermobile joints (Beighton score ≥ 4).

Methods: Patients referred to weight-bearing MRI went through a clinical examination, including Beighton's test, answered back pain-related questionnaires, and were hereafter imaged in supine and standing in a 0.25-T MRI unit. All MRI exams were evaluated for degenerative findings i.e., herniations, disc degeneration, spinal stenosis, disc degeneration, and spondylolisthesis. Subsequently, the lumbar lordosis angle, the sacral angle, and all spondylolisthesis' slippages were measured for both positions.

Results: Of 257 LBP patients, Beighton score ≥ 4 were seen in 48 patients, and these included more females (81.3% vs. 51.7%), younger patients (mean difference [MD]: -8.1 years), and had less degenerated lumbar discs (sum-score MD: -0.9). No difference between groups in degenerative MRI findings was found, although, a non-significant tendency (p = 0.072) to a higher number of anterolisthesis in the hypermobile patients. The hypermobile patients had a greater lordosis angle both during supine and standing and a greater sacral angle in supine, however, changes in the angles between supine and standing were without difference between groups. A sensitivity analysis adjusted for gender and age confirmed these findings.

Conclusion: Hypermobility in LBP patients was associated with being female, younger, having increased lumbar lordosis both during standing and in supine, however, was not associated with increased back pain, anterolisthesis grade or more severe lumbar changes between positions.