BACKGROUND:Because of complicated biomechanics of lumbar vertebra, mast facet osteoarthritis, degenerative joint disease and vertebral subluxation usual y occur fol owing lumbar fusion. To avoid adjacent segment disease, researchers have transformed strong internal fixation into elastic fixation, but the treatment outcomes are barely satisfactory. Furthermore, factors involving adjacent segment disease remain unclear. OBJECTIVE:To explore the relationship between L3-4 segment disease fol owing lumbar fusion and gender. METHODS:200 patients undergoing lumbar fusion of L4-5 and L5-S1 in the First Hospital of Shijiazhuang ranging from 2007 to 2016 were enrol ed, and then al otted into male and female groups (n=100 per group) for retrospective analysis. The incidence of L3-4 segment disease was compared between two groups. RESULTS AND CONCLUSION:Compared with the male group, in the female group, the incidence of L3-4 segment diseases at different fusion locations and ranges, the Oswestry disability index and visual analogue scale and each migration range were significantly higher. Logistic regression analysis showed that gender was one of the independent factors of L3-4 segment disease following lumbar fusion of L3-4 and L5-S1. These findings suggest that gender is one of the influencing factors of L3-4 segment disease after instrumented lumbar;thereby, adjacent segment disease occurs frequently in female patients.

Objective: Explore the method for volumetric measurement of alveolar bone defect. Methods: This study applied 2 advanced preoperative volume measurement methods: three-dimensional (3D) printing and computer-aided engineering (CAE). Twenty-six unilateral alveolar cleft patients were enrolled in this study from April 2015 to December 2016. Their computed tomographic data were sent to 3D printing and CAE software. A simulated graft was used on the 3D-printed model, and the graft volume was measured by water displacement. The volume calculated by CAE software used mirror-reverses technique. Results: The volume of alveolar bone defect could be detected by both methods. The average volume of the simulated bone grafts by 3D-printed models was 1.61 ml, a little higher than the mean volume of 1.60 ml calculated by CAE software. The difference between the 2 volumes was from -0.34 ml to 0.54 ml. The paired Student t test showed no statistically significant difference between the volumes derived from the 2 methods. Conclusions This study demonstrated that the volume of alveolar bone defect is about 1.6ml in unilateral alveolar cleft patients aged 9-12 years. The mirror-reversed technique by CAE software is as accurate as the simulated operation on 3D-printed models. These findings further validate the use of 3D printing and CAE technique in alveolar defect repairing.