Objective To investigate the causes of re-fractures of non fracture vertebral body after percutaneous kyphoplasty (PKP).Methods 512 patients (618 vertebral bodies) treated with PKP because of osteoporosis VCFs were recruited from June 2010 to June 2014.There were 107 males (121 vertebral bodies) and 405 females (497 vertebral bodies) with the mean age of 70.38±7.59 years old (51 to 91 years).There were 406 single segment fracture and 106 double segment fractures cases,and the fracture segments were T4 to L5.The T value of the patients' bone mineral density (BMD) was from-1.0 to-5.2 SD.The clinic characteristics of all the patients including age,sex,body weight,body height,body mass index (BMI),BMD score of the spine,volume of bone cement,restoration rate of anterior/middle vertebral height,postoperative complications (pulmonary embolism,bone cement leakage,nerve injury),and treated vertebral level were analyzed.Results 52 patients (10.16％,52/512) experienced refractures of non fracture vertebral body after kyphoplasty,and 4 experienced re-fracture of the fracture vertebral body after kyphoplasty.The average age of the 52 patients was 71.88±7.74 years old,meanwhile,the ratio of female was 94.23％ (49/52),the mean T value of BMD-4.03±0.60 SD,the ratio of initial double segment fractures 51.92％ (27/52).In addition,among the 456 cases with no fracture,the average age was 70.21±7.56 years,the ratio of female was 77.19％ (352/456);the mean T value of BMD was-2.89±0.55 SD;the ratio of initial double segment fractures was 17.32％(79/456).The data above (age,T value of BMD and initial double segment fractures) were all with statistical significant differences.Whereas the BMI,volume of bone cement,intervertebral disc leakage and restoration rate of anterior/middle vertebral height had no significant difference between the two groups.Furthermore,in the re-fracture of non fracture vertebral body group,32 cases (61.54％,32/52) were nonadjacent fractures,and 20 (38.46％,20/52) were adjacent fractures.Conclusion Osteoporosis degree,female and initial double segment fractures were major risk factors in the development of re-fracture of non fracture vertebral body after PKP.

BACKGROUND:Angiotensin-converting enzyme as a key enzyme of the renin-angiotensin system, through the degradation effects of substance P mechanism, is involved in the occurrence and development of Alzheimer’s disease.
OBJECTIVE:To research the relationship between angiotensin-converting enzyme gene polymorphism and Alzheimer’s disease in Jiamusi region, as wel as the effect of gender and hypertension on the relationship.
METHODS:This case-control study included 96 Alzheimer’s disease patients. Another 102 subjects served as controls coming from the same area and in the same environmental condition. DNA segments were amplified using PCR in 20 g/L agarose gel electrophoresis and observed under ultraviolet lamp. II, ID, DD genotypes and genotype frequencies were calculated for statistical analysis. On this basis, according to clinical data col ected, we investigated association of Alzheimer’s disease with hypertension and gender.
RESULTS AND CONCLUSION:There was significant difference between Alzheimer’s disease patients and controls in angiotensin-converting enzyme genotypes and al ele frequency. There was statistical y significant difference between Alzheimer’s patients with hypertension and controls in angiotensin-converting enzyme genotypes and al ele frequency. There was no statistical difference between Alzheimer’s disease patients with different genders and controls in angiotensin-converting enzyme genotypes and al ele frequency. These findings indicate that there are some relationships between angiotensin-converting enzyme polymorphism and Alzheimer’s disease. II genotype is a risk factor for Alzheimer’s disease, angiotensin-converting enzyme II genotype is a risk factor for Alzheimer’s disease with hypertension.

Objective:To investigate the safety and clinical efficacy of primary anterior lesion removal and bone graft fusion combined with secondary posterior fixation in the treatment of cervical suppurative spondylitis.Methods:Retrospective analysis was performed on the data of twenty cervical suppurative spondylitis patients treated with primary anterior lesion removal and bone graft fusion combinedwith secondary posterior fixation in our hospital from May 2016 to December 2020, including 14 males and 6 females. Aging from 40 to 87 years, with an average of 60.2±12.6 years. The laboratory tests of preoperative blood culture, such as white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and hypersensitive C-reactive protein (CRP) were performed.The selection and duration of antibiotic usewere guided according to bacterial culture and laboratory test results. visual analogue scale (VAS) score, Japanese Orthopeadic Association (JOA) score and Frankle classification of neurological function were evaluated before surgery, 3 months after surgery, and 12 months after surgery, so were the Cobb angle and segmental angle of cervical lordosis. Single factor repeated measure ANOVA was used for statistical analysis of data.Results:Surgeries were performed successfully for all the 20 patients. 9 cases of Staphylococcus aureus, 4 cases of Streptococcus and 2 case of Escherichia coli were detected by pathogen examination. The remaining 5 cases were negative in bacterial culture. All 20 patients were followed up for 18.3±6.7 months. WBC, ESR and CRP at 3 and 12 months after surgery were significantly lower than those before surgery ( F value: 17.90, 30.65, 18.64, P<0.001). The VAS at 3 months after surgery 1.35±0.49 and 12 months after surgery 1.15±0.48 were significantly lower than that before surgery 4.95±1.10 ( F=176.12, P<0.001). The JOA score at 3 months after surgery 15.40±1.93 and 12 months after surgery 16.06±1.36 were significantly better than that before surgery 11.45±2.78 ( F=65.33, P<0.001). The Cobb Angle of C 2-C 7 cervical lordosis after surgery 14.45°±4.36° and 12 months after surgery (13.70°±3.15°) were significantly larger than that before surgery (8.25°±4.36°) ( F=72.54, P<0.001). Cobb angle of the lesion segment after surgery (3.60°±1.90°) and 12 months after surgery (2.90°±1.44°) were significantly better than that before surgery (-3.55°±5.74°) (negative value indicated kyphosis) ( F=42.49, P<0.001). Bone fusion was observed in all graft areas at 12 months of follow-up. Conclusion:The treatment of cervical suppurative spondylitis with primary anterior lesion removal and bone graft fusion combined with secondary posterior fixation can effectively obtain intraspinal decompression, improve pain and nerve function, as well as restore cervical stability and correct kyphosis, with satisfactory clinical efficacy.

Objective:To investigate the relationship between ankle stability and associated muscle load around the ankle and the effect of a parachute ankle brace (PAB) on ankle inversion and associated muscle load around the ankle during landing through the simulated paratrooper semi-squat landing field experiment.Methods:In August 2021, 37 male paratroopers were randomly selected as the study objects to perform parachute landing training in the semi-squat posture on the 1.5 m and 2.0 m jump platforms with or without PAB, respectively. The coronal plane tilt angle of ankle joint and the percentage of maximum voluntary contraction (MVC%) of associated muscles around ankle joint during the process were measured and correlation analysis was conducted. And the effect of wearing PAB on the coronal plane tilt angle of ankle joint and the associated muscles around the ankle joint was analyzed.Results:During the semi-squat landing, the MVC% of the tibialis anterior muscle, lateral gastrocnemius muscle and peroneus longus muscle were positively correlated with the ankle coronal plane tilt angle in paratroopers wearing and without wearing PAB, and the correlations were statistically significant ( P<0.05). At the same height, compared with those without PAB, the coronal plane tilt angle of the ankle joint decreased during semi-squat landing in paratroopers PAB, and the differences were statistically significant ( P<0.05). At the landing moment of the same height, compared with those without PAB, the MVC% of lateral gastrocnemius muscle decreased and the MVC% of peroneus longus muscle increased in paratroopers wearing PAB, and the differences were statistically significant ( P<0.05). After the landing moment until the standing stage (100-200 ms) at 1.5 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the differences were statistically significant ( P<0.05). In the post-standing stage (200 ms) at 2.0 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the difference was statistically significant ( P<0.05) . Conclusion:Wearing PAB can reduce the ankle coronal plane tilt angle, improve ankle stability, reduce the muscle load of the lateral gastrocnemius muscle at the moment of landing, and reduce the load of the tibialis anterior muscle after landing, but increase the peroneus longus muscle load at the moment of landing.

Objective:To investigate the relationship between ankle stability and associated muscle load around the ankle and the effect of a parachute ankle brace (PAB) on ankle inversion and associated muscle load around the ankle during landing through the simulated paratrooper semi-squat landing field experiment.Methods:In August 2021, 37 male paratroopers were randomly selected as the study objects to perform parachute landing training in the semi-squat posture on the 1.5 m and 2.0 m jump platforms with or without PAB, respectively. The coronal plane tilt angle of ankle joint and the percentage of maximum voluntary contraction (MVC%) of associated muscles around ankle joint during the process were measured and correlation analysis was conducted. And the effect of wearing PAB on the coronal plane tilt angle of ankle joint and the associated muscles around the ankle joint was analyzed.Results:During the semi-squat landing, the MVC% of the tibialis anterior muscle, lateral gastrocnemius muscle and peroneus longus muscle were positively correlated with the ankle coronal plane tilt angle in paratroopers wearing and without wearing PAB, and the correlations were statistically significant ( P<0.05). At the same height, compared with those without PAB, the coronal plane tilt angle of the ankle joint decreased during semi-squat landing in paratroopers PAB, and the differences were statistically significant ( P<0.05). At the landing moment of the same height, compared with those without PAB, the MVC% of lateral gastrocnemius muscle decreased and the MVC% of peroneus longus muscle increased in paratroopers wearing PAB, and the differences were statistically significant ( P<0.05). After the landing moment until the standing stage (100-200 ms) at 1.5 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the differences were statistically significant ( P<0.05). In the post-standing stage (200 ms) at 2.0 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the difference was statistically significant ( P<0.05) . Conclusion:Wearing PAB can reduce the ankle coronal plane tilt angle, improve ankle stability, reduce the muscle load of the lateral gastrocnemius muscle at the moment of landing, and reduce the load of the tibialis anterior muscle after landing, but increase the peroneus longus muscle load at the moment of landing.