Objective To analyze the correlation of vertebral osteophyte and lumbar disc degeneration in the elderly people and explore the possible mechanism of osteophyte formation. Methods X-ray and MRI data of 120 elderly people with backache or leg pain were retrospectively analyzed. Osteophyte was classified into four grades by X-ray according to the method proposed by Nathan. Discs with osteophyte were defined as occurring when osteophyte of grade II or greater were present. Lumbar disc degeneration was classified into five grades by MRI according to the method proposed by Pfirrmann. The obtained parameters were statistically treated and analyzed. Results Osteophyte and age were positively correlated at every lumbar disc level (P < 0.05). The proportion of osteophyte in L3/4 (76.7%) and L4/5 (70.08%) were more severe than that in L1/2 (31.7%) and L2/3 (46.7%). Osteophyte and lumbar disc degeneration were positively correlated at every lumbar disc level (P < 0.01). Conclusion Osteophyte becomes more severe with the increasing of lumbar disc degeneration. The vertebral stress after lumbar disc degeneration may be the main cause of osteophyte.

Objective To establish rabbit model of scoliosis induced with stable asymmetric lumbar loads. Methods Scoliosis was induced in 10 two-month-old New Zealand rabbits using 316L stainless steel springs placed between the unilateral transverse processes of L2 and L5. Serial radiographs were documented before and at 1, 4, 8, 9 and 12 weeks after the operation. At weeks, the rabbits were randomly divided into SR group (n=5) with the spring removed and SK group (n=5) without spring removal. Results All the rabbits survived the experiment with Cobb angle all greater than 10°at the end of the experiment. Significant changes were found in the Cobb angles and kyphotic angles at 1, 4 and 8 weeks after the operation (P<0.05). At 8 weeks, the Cobb angle, the kyphotic angle and the length of the spring were similar between SR and SK groups (P>0.05), and in the 4 weeks following spring removal in SR group, the Cobb angle and the kyphosis decreased significantly compared with those in SK group (P<0.05). Micro-CT showed that the BV/TV of the concave side was greater than that of the convex side. The length of the spring did not show obvious changes during the experiment (P>0.05). Conclusion Asymmetric lumbar loading is a convenient, time-saving, and highly reproducible approach for establishing rabbit models of scoliosis.

Objective To establish rabbit model of scoliosis induced with stable asymmetric lumbar loads. Methods Scoliosis was induced in 10 two-month-old New Zealand rabbits using 316L stainless steel springs placed between the unilateral transverse processes of L2 and L5. Serial radiographs were documented before and at 1, 4, 8, 9 and 12 weeks after the operation. At weeks, the rabbits were randomly divided into SR group (n=5) with the spring removed and SK group (n=5) without spring removal. Results All the rabbits survived the experiment with Cobb angle all greater than 10°at the end of the experiment. Significant changes were found in the Cobb angles and kyphotic angles at 1, 4 and 8 weeks after the operation (P<0.05). At 8 weeks, the Cobb angle, the kyphotic angle and the length of the spring were similar between SR and SK groups (P>0.05), and in the 4 weeks following spring removal in SR group, the Cobb angle and the kyphosis decreased significantly compared with those in SK group (P<0.05). Micro-CT showed that the BV/TV of the concave side was greater than that of the convex side. The length of the spring did not show obvious changes during the experiment (P>0.05). Conclusion Asymmetric lumbar loading is a convenient, time-saving, and highly reproducible approach for establishing rabbit models of scoliosis.