Comparison of Histological Changes in the Ligamentum Flavum from Spinal Canal Stenosis Patients with and without Diabetes Mellitus

Objective: Lumbar spinal canal stenosis (LSCS) has prominent position in spinal disorders of the elderly. Ligamentum flavum hypertrophy plays a dominant role in narrowing of the LSCS. There are some clues that Ligamentum flavum hypertrophy is associated with diabetes mellitus. Our objective was comparison of histological properties of ligamentum flavum in Lumbar spinal canal stenosis patients with and without diabetes mellitus. Materials and Methods: In this case control study, during 9 months, twenty-nine patients, who were candidate for decompressive laminectomy because of ligamentum flavum hypertrophy, were studied. They were labeled as diabetic if had history of diabetes mellitus or fasting blood sugar ≥126mg/dl for two times or blood sugar >200mg/dl anytime with symptom of hyperglycemia. Ligamentum flavum was removed through surgery. Samples were evaluated by pathologist using Hematoxylin &Eosin, Masson’s trichrome and Verhoeff van Gieson staining. Evaluation includes grading of fibrosis, loss of elastin fibers, calcification and number of cellularity of samples. Data analyzed with Fisher’s test and Mann-Whitney test. Results: In this study 41% of patients (12 persons) were suffering from diabetes mellitus. There was no significant difference between diabetic and nondiabetic patients in histological properties. (P>0.05); but the weight of diabetic patients was higher than nondiabetics (P-value =0.038) Conclusion: These results show that diabetes mellitus has no effect on histological change in ligamentum flavum of spinal canal stenosis and mechanical stress (due to overweight) has a more important role in pathogenesis of spinal canal stenosis.