Background: Upper lumbar disc herniation (ULDH) is easy to be misdiagnosed due to its special anatomical and atypical clinical features. Few studies have identified the relationship between ULDH and adjacent wedge-shaped vertebrae (WSV).
Hypothesis: WSV may have some indicative relations withULDH.
Patients and methods: Between January 2003 and October 2013, 47 patients (27 males and 20 females; mean age, 41.2 years) with single-level ULDH (as study group) and 47 sex- and age-matched healthy volunteers (as control group) were studied by radiograph. The two groups were compared with respect to age, sexual proportion, body mass index (BMI), kyphotic angle, and the proportion of WSV. Also, correlative analyses were conducted in the study group to investigate the relation between the kyphotic angle of target vertebrae and other factors including age, BMI, Cobb angle, JOA score and bone mineral density (BMD).
Results: The average kyphotic angle in the study group was 11° (4°-22°), while the average kyphotic angle in the control group was 2° (0°-7°). Obviously, the mean kyphotic angle in the study group was statistically larger than that in the control group (t=13.797, P<0.001). The proportion of WSV in the study group was significantly larger than that in the control group (x(2)=36.380, P<0.0001). The correlations between kyphotic angles and other items (i.e., age, BMI, BMD, Cobb angle and JOA score) in the study group and the control group were low or uncorrelated.
Conclusions: WSV are indicatively associated with adjacent ULDH. Thus, ULDH should be alerted when WSV are first found in radiograph and accompanied by clinical symptoms.
Keywords: Disc herniation; correlative analysis; upper lumbar spine; wedge-shaped vertebrae.