Effect of bone mineral density on lumbar discs in young adults

Abstract

Bone mineral density (BMD) might be a risk factor for lumbar disc herniation (LDH) in young adults, but there is not enough data concerning this effect. Several studies have been performed on elderly and osteoporotic patients. Thus, we aimed to investigate the effect of BMD on the etiopathogenesis of LDH in young adults.One hundred patients (mean age: 38.45 ± 8.92 years; 50 men and 50 women) were enrolled this case–control study and classified into 2 groups, as follows. The case group (G-I) included 50 patients with symptomatic LDH who were hospitalized in the Physical Medicine and Rehabilitation Clinic, and the control group (G-II) included 50 patients with lower back pain but no finding of LDH detected using magnetic resonance imaging. Patients in the G-II were recruited among those admitted to the outpatient clinic at the time of the study, and whose age and sex were matched to those of the study group. Women in menopause were excluded from the study. BMD analysis by dual energy x-ray absorptiometry was performed in both groups.The mean values of the femur neck and lumbar spine BMD were 1.02 ± 0.13 and 1.19 ± 0.14 g/cm2, respectively. There was no statistically significant relationship between BMD and LDH in this population.This result may mean that in a normal range, BMD does not exert a compressive load on the lumbar discs in young adults and therefore may not lead to LDH by this mechanism and the load.

The Relationship Between Bone Mineral Density and Lumbar Disc Herniation in Postmenopausal Women

“…While the effect of BMD on disc degeneration and osteoarthritis has been widely observed in previous studies [ 16 - 20 ], the LDH-BMD relationship has been understudied. Previous studies were conducted in a young, healthy adult population collected from another study or in young patients with a small sample size [ 10 , 11 ]. We evaluated postmenopausal women who suffer from low back pain, and our results indicated that, after adjusting for covariates, higher lumbar BMD and higher femoral neck BMD were significantly associated with an increased risk of LDH (p<0.05).…”

“…The incidence of LDH has been shown to increase with age [ 7 , 10 , 11 ]. In the present study, consistent with previous literature, there was a positive correlation between the age of the patients and LDH (p=0.001).…”

“…LDH was defined as "localized or focal displacement of disc material beyond the limits of the intervertebral disc space," according to the latest recommendations of the North American Spine Society [ 15 ]. The term "localized" or "focal" was defined as the extension of the disc material to less than 25% of the circumference of the disc as viewed in the axial plane [ 11 ]. The MRI scans (L1 to S1) were assessed by an independent reader who was blinded to the patients' details.…”

“…Nevertheless, although lumbar vertebral bones and lumbar intervertebral discs are close to each other both biomechanically and anatomically, to our knowledge, the association between BMD and LDH has not been studied in postmenopausal women before. Two studies were detected evaluating this relationship in young healthy people living in an urban area and young patients, with the exclusion of postmenopausal women, and the studies found no significant relationship [ 10 , 11 ].…”

The Association of Lumbar Disc Herniation with Lumbar Volumetric Bone Mineral Density in a Cross-Sectional Chinese Study

“…Disc degeneration results in a shift of load from the nucleus to the annulus, leading to reduced density in the trabecular core and increased density in cortical bone [ 38 ]. DXA cannot distinguish between cortical bone and trabecular bone, and it is sensitive to the presence of aortic calcifications, vertebral fracture, spine degeneration such as vertebral osteophytes, end-plate sclerosis, facet joint degeneration, and ligament calcification, which can all lead to falsely increased lumbar vertebral areal BMD (aBMD) [ 39 ]. Although DXA is a well-established technique, QCT is a more accurate method for BMD assessment and a more sensitive modality for the evaluation of BMD changes [ 7 , 40 ].…”