Aim: Lumbosacral parameters can be affected in ankylosing spondylitis (AS) and chronic mechanical back pain.We compared lumbosacral parameters between patients with AS and chronic mechanical back pain to identify specific changes in AS.
Material and Methods:This study has a retrospective design. A total of 42 patients with AS (16 females, 26 males) and 66 patients with chronic mechanical back pain (31 females, 35 males) were enrolled in the study.Lumbar lordosis angle (LLA), Lumbosacral angle (LSA), Sacral tilt (ST), and Lumbosacral disc angle (LSDA) were measured using digitalized standing lateral lumbar radiographs. CRP and ESR concentrations of AS patients were obtained from the hospital database.
Results: LLA, LSA, ST and LSDA were significantly smaller in the patients with AS (p < 0.05).CRP and ESR were significantly and negatively correlated with LLA and LSA (r = -0.516, p < 0.001; r = -0.401, p = 0.009 for CRP and r = -0.623, p < 0.001; r = -0.474, p = 0.002 for ESR). In AS patients, LLA was significantly and positively correlated with LSA and ST (r = 0.490, p = 0.001; r = 0.399, p = 0.009). Additionally, LSA was significantly and positively correlated with LSDA (r = 0.613, p < 0.001).
Conclusion: The sagittal lumbosacral parameters of patients with AS were found to be significantly different from those of patients with chronic mechanical back pain. İnflammation negatively affects lumbosacral alignment in AS. The identification of specific changes in sagittal spinal alignment in patients with AS will contribute to the establishment of appropriate rehabilitation strategies and surgical plans.
Key words: Ankylosing Spondylitis; Lumbosacral Balance; Lumbosacral Alignment; Lumbar Lordosis; Inflammation.