BACKGROUND: The deficiency of perfect animal femoral head necrosis model limited its further investigation. OBJECTIVE: To verify the feasibility of establishing rabbit femoral head necrosis models using liquid nitrogen rsfdgeration method, and to provide a foundation for subsequent research. METHODS: A total of 20 adult, New Zealand, white rabbits were selected in the study. The round ligament of femur was not cut off and femoral head was not dislocated, and the exposed femoral head were quick frozen using cotton bud carrying liquid nitrogen for successive 25 times, with 10 s per time. The specimens were examined by gross anatomy, X-ray film, MRI and histological observation at day 3, 7 and weeks 2, 4, 6, and 8 after operation. RESULTS AND CONCLUSION: The histolOgical section showed that chondrocyte, osteccyts, and myelold tissues presented necrosis in freezing and periphery at 3days after model preparation, and the repair process appeared at 2weeks after operation. The articular surface of femoral heads appeared collapse at 4 weeks after operation, and these changes became obvious at 6 weeks. The femoral head presented ostecarthdtis-like disorder, with seriously collapsed articular surface at8 weeks, and the contour of femoral head changed in 2 animals. The results demonstrated that without hip dislocation, rabbit femoral head necrosis models can be established successfully using liquid nitrogen refrigeration method. This method is simple, feesible, with high succeed rate, which can be used in subsequent research.

Objective To investigate the short-term clinical outcome and radiographic assessment of Oblique Lateral Interbody Fusion to indirectly decompress for the degenerative lumbar spinal stenosis with or without lumbar spine instability.Methods All of 15 patients with diagnosis of degenerative lumbar spinal stenosis with or without lumbar spine instability (7 males and 8 females,age from 36y to 86,mean age 53.5± 15.2 y) were treated with OLIF surgery in our spine surgery center.The main symptoms included lumbar pain with unilateral or bilateral leg pain or intermittent claudication.The Visual analogue scale (VAS),Oswestry disability index (ODI),Japanese Orthopaedic Association (JOA) and SF-36 scores were used to assess the clinical effect pre and post-operatively while radiographic assessments were compared as well as comprehensive evaluation of the radiography,MRI,and CT images.Results All patients were followed up for an average of 12.5 (6-21) months.And all the patients enjoyed alleviation of symptoms although varying in extent.The radiographic results showed satisfactory indirect decompression of the neuro-elements,as well as reduction of the lumbar spine.The DH,VH and FH increased by 3.6mm,4.8mm and 5.7mm respectively.The foraminal area (FA) and canal area (CA) enlarged by 44.2mm2 and 24.8mm2.The canal diameters (CD) and disk-flavum ligamentum space (DLFS) increased by 2.5mm and 2mm respectively.The foraminal diameters (FD) increased by 0.3mm,but there was not significantly different.The segment angle and lumbar lordosis angle were partially restored after operation,and the angle increased by 14 ° and 13.6 °respectively.One of the patients had a transient paresthesia and mild weakness of muscle when hip flexor and recovered within 3 months.Another one case encountered serious back pain after a month and alleviated after reoperation with PPF.Conclusion OLIF can provide a satisfactory outcome for the patients with degenerative lumbar spinal stenosis through indirectly decompression,which can increase the disc height,foramen height,canal diameter and disk-flavum ligamentum space.

BACKGROUND:Zinc-modified calcium silicate (CaSiO3) bioceramics coating on the titanium surface prepared in preliminary experiments has good chemical stability and antibacterial property. OBJECTIVE:To observe the effects of zinc-modified CaSiO3 bioceramics coating on osteointegration. METHODS:MC3T3-E1 cels were respectively cultured on the titanium with zinc-modified CaSiO3 bioceramics coating (experiment group), titanium with CaSiO3 bioceramics coating (control group) and pure titanium (blank control group). Then, cel adhesion, proliferation, calcification rate and the expression of type I colagen and osteocalcin were detected. The implant materials mentioned above were respectively inserted into the femurs of New Zealand white rabbits, and after 1.5 months, the osteoproliferation and osteointegration between the implants and the host were tested. RESULTS AND CONCLUSION:In vitro experiment: The number of adhesive cels at 12 hours after co-culture was significantly increased in the experimental group compared with the control group and blank control group (P < 0.05). At 14 days after co-culture, cel proliferation ability and ability of calcium nodule formation in the experiment group were significantly better than those in the other groups (P < 0.05). At 21 days after co-culture, there was no significant difference in the expression of type I colagen, but the expression of osteocalcin in the experiment group was higher than that in the control group and blank control group (P < 0.05).In vivo experiment: In the experiment group, a large amount of bone substances were detected, the coating materials directly contacted with the bone interface, new bone tissues and little fibrous tissues were observed at the interface. In contrast, there was a small amount of bone hyperplasia in the control group and almost no bone hyperplase in the blank control group. Moreover, a small part of the implant directly contacted with the bone interface and the most part was separated from bone trabeculae by fibrous tissues. These findings indicate that zinc-modified CaSiO3 bioceramics coating can enhance the ability of osteointegration between titanium implants and the host.

Objective To investigate the clinical outcomes of lateral lumbar interbody fusion (LLIF) in lumbar corpectomy and reconstruction.Methods Overall,8 patients with lumbar burst fracture and dislocation and 1 patient with postoperative infection of lumbar fracture who were treated with LLIF from May 2014 to May 2016 in our hospital were retrospective analyzed.The included 9 patients,with 8 males and 1 female,had an average age of 5.5±6.7 years (28-59 years).Among them,4 cases were injured at L2 segment,4 cases at L3,and 1 case at L4.The main symptoms were back pain and dysfunction of perineum and lower extremity caused by nerve injury.Preoperative neurological functions were assessed according to the American Spinal Injury Association's modified Frankel classification,with 1 case at Grade A,2 Grade B,3 Grade C,1 Grade D,and 2 Grade E.The operation time,the amount of intraoperative bleeding,and the length of hospital stay were recorded.The clinical outcomes were evaluated by the ASIA grading,visual analog scale (VAS),and Oswestry disability index (ODI).The changes of body temperature,erythrocyte sedimentation rate (ESR),and C-reactive protein (CRP) before and after surgery were recorded for the patients with infection.The recovery of lumbar lordosis and the fusion of bone graft were evaluated by the radiographic examination of the lumbar spine and lumbar sagittal Cobb angle.Results The average operation time was 73± 12.7min,ranging from 50 to 90 min.The amount of intraoperative bleeding was 650±35.3 ml,with a range between 30 and 150 ml.All incisions were fully healed.The length of hospital stay was 5.0± 1.0 days,ranging from 4 to 7 days.All patients were followed up for 16.4±3.8 months (11-24 months).The VAS scores and ODI were improved significantly after surgery compared with pre-operation.For patients with infection,body temperature,ESR,and CRP went back to normal within 3,17,and 25 days after surgery,respectively.The ASIA improvement was observed in six patients,with one from grade A to C,one from grade B to D,one from grade B to E,one from grade C to D,one from grade C to E,and one from grad D to E.The lordosis of lumbar spine and surgical segments were restored significantly after surgery,with an increase by 19.9 and 5.1 degree,respectively.All the patients achieved bone fusion after operation.Hip weakness,thigh pain,numbness,retroperitoneal hematoma,and other complications were not observed in these patients.Conclusion The lateral lumbar interbody fusion is safe,reliable,and clinically satisfactory for the treatment of lumbar burst fractures,infections,or lumbar anterior and middle column pathology.This method provides new ideas for the treatment of lumbar anterior and middle column pathology.

Objective To investigate the clinical outcomes using posterior percutaneous endoscopic cervical discectomy (PECD) for single level cervical spondylotic radiculopathy (CSR).Methods From October 2015 to June 2016,33 patients (23 men,10 women,mean age 54.0 years,range from 30 to 85 years) who had single level CSR were treated by PECD,and the medical records were reviewed.All patients were followed up for an average of 13.5±4.6 months (range from 12 to 22 months).The operation related parameters (operation time,estimated blood loss,length of hospitalization,complications) and clinical parameters,including neck visual analog scale (Neck-VAS),ann visual analog scale (Arm-VAS),neck disability index (NDI) and the modified Macnab criteria were assessed at 3,6,and 12 months postoperatively and last follow-up.Disc height,shell angle,C2-C7 Cobb angle and range of motion were recorded preoperatively and at 3 months,6 months,12 months and last follow-up postoperatively.Results The mean operation time was 76.4±26.6 minutes (range from 40 to 120 minutes),the mean estimated blood loss was 30.2±15.6 ml (range from 20 to 80 ml),and the mean length of hospitalization was 3.5± 1.1 days (range from 2 to 8 days).There was significant decrease at different time points postoperatively in Neck-VAS,Arm-VAS,and NDI when compared with preoperatively (P＜ 0.05).According to the modified Macnab criteria,there was excellent concordance in 20 patients (60.6％),good in 7 patients (21.2％) and fair in 6 patients (18.2％) at the last follow-up.The disc height was significantly decreased at postoperative 3 months and 1 year compared with at preoperative (F=95.1,P＜0.01).The shell angle of index level (F=35.4.,P＜0.01),upper adjacent level (F=30.1,P＜0.01),lower adjacent level (F=1 1.7,P＜0.01) as well as spinal function units (F=22.2,P＜0.01) were increased significantly at postoperative compared with at preoperative.The range of motion of index level (F=8.1,P＜0.01) and upper adjacent level (F=64.0,P＜0.01) increased significantly at postoperative compared with at preoperative.The range of motion in lower adjacent level (F=1.5,P=0.23),spine functional unit of index level (F=2.9,P=0.06),as well as C2-C7 (F=0.6,P=0.56) had no significant difference between preoperative and postoperative 1 year (P＞0.05).One patient turned into traditional ACDF procedure because of hemorrhage limiting the vision during PECD operation.Upper extremity numbness and pain deteriorated in one case after a PECD procedure and was revised with ACDF at last.No other complications,like spinal cord injury,cervical root injury,cerebral spinal fluid leakage,infection as well as recurrence were found.Conclusion PECD,which can maintain normal cervical range of motion and intervertebral disc height,is a minimally invasive and essential procedure for CSR treatment with minor trauma,excellent outcome and quick recovery.Surgeon's experience,however,is needed in case of turning into open surgery for good outcome.

Objective:To explore the intervention effects of an Internet-based blood pressure monitoring and management platform in a prehypertensive population.Methods:One hundred and fifty-eight prehypertensive patients who were examined at the Third Xiangya Hospital in Changsha, China, from August to December 2019 were randomly divided into either the experimental or control groups using the random number table method. The experimental group utilized an Internet-based blood pressure monitoring and management platform, whereas the control group utilized regular telephone and SMS health management routines. The intervention duration was 12 months for both groups. Data were analyzed using descriptive analysis, t-tests, chi-square tests, χ 2 tests, and rank-sum tests. Results:Post intervention systolic blood pressure (124.79±9.71 mmHg) (1 mmHg=0.133 kPa) and diastolic blood pressure measurements (77.41±8.21 mmHg) of the participants in the experimental group were significantly lower than those before the intervention (128.29±5.10 mmHg and 79.99±6.01 mmHg, respectively), and significantly lower than those of the control group′s measurements after the intervention (130.00±7.78 mmHg and 80.33±7.90 mmHg, respectively) (all P<0.05). The blood pressure goal attainment rate was significantly higher in the experimental group (23.08%) than that of the control group (8.75%), with statistically significant differences within the experimental group before and after intervention, as well as between the groups post intervention ( P<0.05). Positive lifestyle changes, such as prehypertension knowledge score, active restriction and control of salt and oil intake, reduction of smoking, and exercising weekly, were significantly higher than those in the control group before the intervention (all P<0.05). Conclusion:The use of an Internet-based blood pressure monitoring and management platform can effectively help patients with prehypertension control their blood pressure levels, improve their knowledge about the condition, and improve their lifestyle choices.