Objective To investigate anterior longitudinal ligaments (ALL) ossified surrounding osteotomy vertebra impact the lordosing effect of pedicle subtraction osteotomy (PSO) in patients with thoracolumbar kyphosis secondary to ankylosing spondylitis (AS).Methods We retrospectively reviewed 102 AS patients with thoracolumbar kyphosis treated with single-level PSO at our institution from September 2007 to August 2015.There were 92 male and 10 female.The average age was (35.6±11.8)years old (range from 17 to 65 years old).Patients were stratified into ossified group (54 cases) and non-ossified group (48 cases)based on the presence of ALL ossification adjacent to osteotomy vertebra.Compared the contribution of adjacent disc wedging to total correction of each PSO segment between the ossified and non-ossified groups.The long-term correction loss of spine and pelvic sagittal morphology were also evaluated and compared between the 2 groups.Results Patients in the ossified group accomplished significantly lower amount of correction in single level segment of PSO (36.3°±6.9° vs.41.5°±6.9°),and there was significant difference between the two groups.The contribution of adjacent disc wedging to total correction of PSO was significantly larger in the non-ossified group (22.9％ vs.7.8％,P＜0.001).For subgroups with a minimum 2 year follow-up,loss of corrections concerned sagittal vertical axis (SVA),which was (1.7±4.5) cm vs.(-0.2±4.0) cm in ossified group and non-ossified group,and there was significant difference between the two groups.Pelvic tilt (PT) was 3.5°±8.2° vs.2.0°± 10.4°,lumbar lordosis (LL) was-7.9°±11.9° vs.-0.1°± 11.9° and sacral slope (SS) was 4.5°±9.3° vs.1.6°±7.9°,and there were all significant differences between the two groups.The change of adjacent disc wedging angle was marginally higher in the unossified group (-2.1°±6.2° vs.-0.1°±3.7°,P=0.09),but there was no significant difference between the two groups.No significant correction loss of osteotomy angle was observed in both groups.Conclusion Osteotomy vertebrae accompanied by unossified adjacent ALL in PSO of AS were prone to create more disc-originated lordosing effect immediately after surgery.However,a correction loss might occur more commonly during a long term follow-up.

Objective:To analyze the long-term efficacy of percutaneous kyphoplasty (PKP) assisted with vitamin D in the treatment of elderly thoracolumbar single vertebral osteoporotic vertebral compression fractures (OVCF) and its effect on transfected bone morphogenetic protein-Effects of 7 (BMP-7) /25-hydroxyvitamin D3 [ (25- (OH) -D3] levels.Methods:106 elderly patients with fresh OVCF of thoracic and lumbar vertebrae who were treated with PKP in Li Huili Hospital of Ningbo Medical Center from Jun. 2017 to Jun. 2021 were selected as the research object, and they were divided into two groups according to the random number table method (53 cases in each group) . Both groups were treated with PKP and received conventional anti-osteoporosis treatment and rehabilitation training. On this basis, patients in the treatment group were given vitamin D therapy. Before treatment and 1, 3, 6, and 12 months after treatment, the degree of pain improvement, Cobb angle improvement, bone mineral density, vertebral body compression rate, vertebral body function recovery and serum BMP-7, 25- (OH) -D3 level, and the cement leakage rate of all subjects within 1 year of follow-up was recorded.Results:Two patients in the observation group and 3 patients in the control group lost to follow-up. Comparing the results of before treatment and 12 months after treatment: the control group’s BMD increased from 0.585±0.042 to 0.755±0.0641; BMP-7 increased from 80.02±6.24 to 129.87±10.52;25- (OH) -D3 increased from 9.15±2.16 to 13.52±2.64;and the treatment group’s BMD increased from 0.576±0.039 to 0.868±0.079; BMP-7 increased from 78.36±6.20 to 153.41±12.70; 25- (OH) -D3 increased from 9.01±2.12 to 16.24±2.81; the treatment group had higher increase ( P<0.05) . Meanwhile the control group’s Cobb angle decreased from 13.54±1.81 to 8.05±1.05; vertebral body compression rate decreased from 28.41±3.47 to 19.86±2.29; ODI score decreased from 74.42±7.37 to 24.08±2.41; VAS score decreased from7.54±0.81 to 2.65±0.25,and the treatment group’s Cobb angle decreased from 13.70±1.89 to 7.42±0.97;vertebral body compression rate decreased from 28.97±3.62 to 18.86±2.02; ODI score decreased from75.78±7.43 to 21.39±2.08; VAS score decreased from7.70±0.891 to 2.32±0.20,while the treatment group decreased more ( P<0.05) . In addition, the vertebral refracture rate in the control group was 22.00% (11/50) , while the vertebral refracture rate in the treatment group was 5.88% (3/51) , and there was a significant difference between the groups ( χ 2=5.125, P=0.024) . Conclusion:PKP combined with vitamin D in the treatment of elderly thoracolumbar OVCF can significantly improve the levels of BMP-7 and 25- (OH) -D3, better restore bone mineral density, vertebral body function and correct kyphosis, with a more ideal long-term efficacy.