Distribution pattern and related factors of single osteoporotic vertebral compression fractures / 中华骨科杂志

ABSTRACT

Objective:To identify the anatomical distribution of and factors related to single-segment osteoporotic vertebral compression fractures (OVCF).Methods:The radiology and clinical data of 944 patients with single-segment OVCF hospitalized in Zhongda Hospital Southeast University between June 2016 and October 2020 were retrospectively analyzed, including 175 males and 769 females, aged 72.1±9.6 years (range, 45-97 years). The anatomical distribution of OVCF was quantified. The demographics, comorbidity profile, spine trauma, back pain duration, vertebral compression degree, and bone mineral density of the OVCF patients in different anatomical segments were summarized and compared.Results:Of the 944 single-segment OVCF, 864 were located in the lower thoracic and lumbar spine that peaked at L 1 (Modal-1 group), and 80 were located in the middle and upper thoracic spine (Modal-2 group) that peaked at T 7, demonstrating an asymmetric bimodal distribution. The difference in the female/male ratio between the two groups was insignificant (χ 2=0.06, P=0.803). Patients in Modal-2 were aged 75.0±9.8 years and on average older than the patients (aged 71.8±9.6 years) in Modal-1 ( t=2.78, P=0.005). The female patients in Modal-2 (aged 75.0±9.6 years) were significantly older than that (aged 71.2±9.3 years) in Modal-1 ( t=3.17, P=0.002). The ratio of back pain duration for <1 week in Modal-2 (43.8%) was lower than that in Modal-1 (60.2%), and the ratio of back pain for 1-weeks (28.8%) was significantly higher than that (15.5%) in Modal-1 (χ 2=11.50, P=0.009). The most frequently reported spine traumas in Modal-2 (50.0%) were heavy lifting injury, lumbar sprain, and strenuous cough, which were significantly different from and less apparent than the fall on ground or crush injury to the spine (64.1%) in Modal-1 (χ 2=60.71, P<0.001). The anterior to posterior height ratio of the fractured vertebrae in Modal-2 was 0.78±0.13, 0.83±0.14, 0.84±0.13, and 0.78±0.18 in the OVCF patients complaining of back pain for <1 week, 1-weeks, 2-weeks, and >4 weeks respectively, showing no significant difference between groups ( F=1.01, P=0.009). In Modal-1, the anterior to posterior height ratio of the fractured vertebrae was lower in the OVCF patients complaining of back pain for 2-weeks (0.80±0.15) and >4 weeks (0.77±0.19) than in those with back pain for <1 week (0.85±0.11) and 1-weeks (0.86±0.14), with sinificant differences ( P<0.05). 32.4% (306/944) of the OVCF patients had one of the following geriatric comorbidities hypertension, diabetes mellitus, coronary heart disease, cerebral infarction, and chronic obstructive pulmonary disease. The OVCF patients in Model-2 had higher comorbidity of coronary heart disease (21.3%) and cerebral infarction (36.3%) than those in Model-1 (11.6% and 20.3%). Bone mineral density information was available from 371 patients (308 females). In the age groups of <70, 70-, and >80 years, no significant difference was detected in the T-score values of the lumbar spine or hip joint between the OVCF patients in Model-1 and Model-2 ( F=0.13, P=0.880; F=0.62, P=0.538). Conclusion:Single-segment OVCF feature an asymmetric bimodal distribution that is demarcated by the T 10 vertebrae. The distribution pattern is not determined by gender or baseline bone mineral density but highlights the risk of mechanical stress and vertebral fragility within a specific segment. OVCF in the middle and upper thoracic spine is less frequent but common in older patients with higher comorbidity of coronary heart disease and cerebral infarction, which tend to be caused by less apparent spine trauma and maintain vertebral compression but complain of long back pain duration.