At EuroSpine (1-3 October, Lyon, France), Kiyotaka Yamada (Department of Orthopaedic Surgery, JA Hiroshima General Hospital, Hiroshima, Japan) reported that bone marrow oedema adjacent to the vertebral endplate is correlated with low back pain in elderly patients with degenerative lumbar scoliosis. He explained that the biomechanical stress loaded on the vertebral endplate at the concave side of scoliosis might be a cause of low back pain in this patient population.
Yamada stated that the clinical symptoms of degenerative lumbar scoliosis include leg pain and/or low back pain. He added that while neural compression (such as stenosis of the spinal canal) is thought to be the cause of leg pain in patients with the condition, the cause of the low back pain is “controversial” (suggested causes, based on radiological parameters, include imbalance, instability, or mechanical load). However as there is an association between bone marrow lesions (ie. oedema) on MRI and pain in patients with osteoarthritis of the knee, Yamada and his fellow investigators developed the hypothesis that “bone marrow oedema on MRI is correlated with low back pain associated with degenerative lumbar scoliosis in elderly patients.” Therefore, the purpose of their study was to evaluate this correlation in this patient population.
In the cross-sectional observational study, 120 patients who were aged >65 years and who had de novo lumbar scoliosis (Cobb angle >10 degrees) were spilt into two groups: low back pain alone (64) and leg pain alone (56: control group). The clinical outcome measures were age, gender, body mass index, and lumbar tenderness, and the radiological outcome measures were Cobb angle, scoliotic laterality, location of the intervertebral vacuum, and bone marrow oedema on MRI. Yamada reported: “We scored the area of lesion. Score 0 was no lesion, score one was a lesion on less than half of the vertebral body, and score two was a lesion on more than half of the vertebral body.”
There were no significant differences between the two groups in terms of the clinical characteristics or in terms of Cobb angle, curve laterality, and location of the intervertebral vacuum. However, significantly more patients in the low back pain alone group tested positive for the presence of bone marrow oedema than did the leg pain alone group (96.9% vs. 37.5%; p<0.001). Furthermore, patients in the low back pain alone group had a significantly higher bone marrow oedema score than those in the leg pain alone group (1.5±0.6 vs. 0.4±0.6, respectively; p<0.001). The correlation between the Visual Analogue Scale and bone marrow oedema score was significant (p<0.001).
Yamada concluded: “Bone marrow oedema adjacent to the vertebral endplate in degenerative lumbar scoliosis is strongly associated with low back pain. In degenerative lumbar scoliosis patients, the biomechanical stress loaded on the vertebral endplate might be the cause of low back pain.”