Objective:To report the clinical manifestations and management of infectious spondylitis following vertebroplasty or kyphoplasty.Methods:Six cases of infectious spondylitis following vertebroplasty or kyphoplasty were analyzed retrospectively which had been treated at Department of Spinal Surgery, Henan Provincial People's Hospital between January 2014 and June 2019. They were 2 males and 4 females, aged from 64 to 81 years. Their visual analogue scale (VAS) scores ranged from 6 to 8 points; their spinal cord function was graded as C in 2 cases and E in 4 according to the American Spinal Cord Injury Association (ASIA) grading. All the patients were treated by sub-total resection of the infected vertebra, long segmental pedicle screw fixation and corresponding antibiotics therapy. The therapeutic efficacy was assessed by the inflammation indexes, imaging examinations and clinical manifestations.Results:The 6 patients were followed up for 12 to 42 months(mean 20.4 months). Their operation time ranged from 295 to 455 min (mean 370.8 min) and blood loss from 760 to 2, 250 mL (mean 1 536.7 mL). There were no such serious complications as dural tear, worsening of neurological symptoms or death. The last follow-up revealed normal body temperature and fine incision healing in all patients. Their inflammatory indexes returned to normal. Imaging examinations at the last follow-up showed no displacement of internal implants, no screw loosening or breakage of screws or rods, good bony fusion at the grafting site, and no inflammatory signals from the infected vertebra. At the last follow-up, their VAS for back pain ranged from 2 to 4 points, the ASIA grading was improved from C to D in 2 patients and maintained E in 4. Eventually, 4 patients recovered independent normal walking but 2 required a walker.Conclusions:Infectious spondylitis following vertebroplasty or kyphoplasty can lead to back pain and neurological dysfunction. Sub-total resection of the infected vertebra, long segmental pedicle screw fixation and corresponding antibiotics therapy can result in fine therapeutic outcomes.

Percutaneous vertebral augmentation is the most commonly used minimally invasive surgery in the treatment of osteoporotic vertebral compression fractures(OVCF).The efficacy and safety have been widely recognized,however,there are still some complications of percutaneous vertebral augmentation.And the most common complication is bone cement leakage,which can lead to nerve root and spinal cord injury,increase the risk of secondary fractures of adjacent vertebral,and even cause serious complications such as pulmonary embolism.The diagnosis,classification,hazard,influence factors and preventive measures of bone cement leakage in vertebral augmentation for OCVF are reviewed in this paper,which will provide reference for prevention and treatment of bone cement leakage in clinical practice.

Objective To evaluate the safety and effectiveness of a curved vertebroplasty (CVP) compared with traditional unipedicular approach vertebroplasty (UVP) in treating osteoporotic vertebral compression fractures (OVCF).Methods This was a retrospective case control study on the clinical data of 77 OVCF patients (12 males,65 females;aged 55-86 years,mean 70.8 years) admitted between July 2013 and December 2016.There were 6 injured vertebrae at T1 10,73 at T11 L2,and 12 at L3 5.The patients were divided into CVP group (36 patients,44 vertebrae) and UVP group (41 patients,47 vertebrae) with no significant difference in baseline clinical variables.Intraoperative and postoperative complications including neurovascular injury were recorded.Operation duration,fluoroscopy frequency,volume of cement per level,cement leakage rate per level treated,cement distribution,and refracture rate were compared between the two groups.Preoperative and postoperative visual analog scale (VAS) and Oswestry disability index (ODI) were compared both within the group and between the groups.Results No severe complications related to puncture were observed.No significant difference was observed for operation duration,fluoroscopy frequency,and cement leakage rate per level treated between the two groups (P ＞ 0.05).Compared with UVP group,CVP group had larger volume of cement per level [(5.0 ± 1.4) ml vs.(4.3 ± 1.6) ml],more uniform cement distribution (none vs.10 cases),and lower refracture rate (0 vs.10％) (P ＜ 0.05).The two groups were followed up for 6-49 months (mean,25.9 months).Significant improvements on the VAS and ODI were noted within each group (P ＜0.01),but there was no significant difference between the two groups (P ＞ 0.05).Conclusions Both CVP and UVP are safe and effective treatments for OVCF.Compared with UVP,CVP entails more uniform cement distribution and lower refracture rate.

Objective To analyse the cement distribution after vertebroplasty and investigate the feasibility and clinical significance of its typing.Methods A retrospective case-series study examining the bone cement distribution on anteroposterior radiograph after vertebral augmentation was conducted on 1 324 patients (2 119 vertebrae) with osteoporotic vertebral compression fractures (OVCF) from May 2009 to May 2016.Among the patients,due to refracture,147 patients suffered two or more surgeries with a vertebral refracture rate of 11.1％.One or more adjacent vertebrae refracture occurred in 105 patients with the adjacent vertebrae refracture rate of 7.9％.The vertebral body was split into four regions on the basis of the central vertical and bilateral pedicle of vertical line.According to the bone cement distribution in the four regions,there were five distribution types:type Ⅰ:1-4 regions;type Ⅱ:2-3 regions;type Ⅲ:1 and 4 regions;type Ⅳ:3 and 4 or 1 and 2 regions;type Ⅴ:1 or 4 regions.The X-ray of 40 patients was randomly typed by three orthopedics physicians,and the complication rate and refracture rate of adjacent vertebrae in each type were calculated.Credibility and repeatability analysis were performed.Results The average credibility of the typing was 92.5％.The Kappa coefficient was 0.850 on average.The repeatability of two times of typing was on average 95％,and the Kappa coefficient was 0.900 on average.From type Ⅰ to Ⅴ,there were 26 cases (3.5％),16 cases (4.5％),29 cases (7.3％),40 cases (9.9％),and 41 cases (18.1％) of adjacent vertebral refracture.There were 10 cases of the same vertebral refracture and 5 cases of scoliosis deformity in the type Ⅴ,with incidence rates of 4.4％ and 2.2％,respectively.Conclusions Being reliable and repeatable,the typing for cement distribution after vertebral augmentation is simple and practicable.The type Ⅳ and Ⅴ cement distribution carries higher risk of refracture in adjacent or the same vertebral body and long-term scoliosis than others types.

BACKGROUND:Currently, the cement delivery device used in vertebral augmentation vertebral augmentation (vertebroplasty and kyphoplasty) has flat tips that cannot be bent. During surgery, we always choose injection cement by symmetric way to keep the balance of power on the biomechanics of the vertebral body, while the traditional cement delivery tube can only be used in ipsilateral vertebral body.
OBJECTIVE:To evaluate the feasibility of curved vertebroplasty device for the treatment of thoracolumbar osteoporotic vertebral compression fractures.
METHODS: Sixty patients (72 vertebral bodies) with osteoporotic vertebral compression fractures were enroled, including 8 cases of double-level vertebral fractures and 2 cases of three-level vertebral fractures. Al operations applied curved delivery device in percutaneous vertebroplasty. We recorded operation time, intraoperative blood loss, and X-ray imaging data through prospective self control study. Treatment effect was evaluated with modified Oswestry disability index, Visual Analogue Scale scores and the World Health Organization Quality of Life assessment. The patients were folowed up for 6 months to 2 years.
RESULTS AND CONCLUSION: (1) Surgery was performed successfuly on al 60 patients. The average operation time was 27 minutes (20-45 minutes) for 50 cases by unilateral transpedicular approach. (2) The mean amount of bone cement in every single vertebral of al 72 vertebrae was averagely 6.4 mL (4.2-9.5 mL). Bone cement distribution had not been found to be biased one-sided without severe leakage. (3) Visual Analogue Scale score and Oswestry disability index were significantly improved at 1 day after treatment (P < 0.05). During the final folow-up, no significant difference was detected as compared with 1 day postoperatively (P > 0.05). (4) The ratio of good quality of life in 1 month than postoperatively (87%) and in the last folow-up (92%) was significantly greater compared with the preoperative ratio (27%) (P < 0.05). (5) These findings confirmed that curved vertebroplasty device in unilateral pedicle puncture could ensure bilateral symmetric distribution of bone cement. Al patients are satisfied with treatment. It is proved to be a feasible simple and safe method.

Objective To analyze cause and preventative measures of neurological complications of spinal osteotomy for thoracolumbar and lumbar kyphosis in ankylosing spondylitis.Methods Data of 126 patients with kyphosis caused by ankylosing spondylitis,who had undergone spinal osteotomy in our hospital from January 2006 to January 2012,were retrospectively analyzed.Among them,18 patients developed neurological complications after spinal osteotomy,including 15 males and 3 females,aged from 25 to 56 years.The average preoperative Cobb angle of these patients was 76.3°.According to American Spinal Injury Association (ASIA) classification,all patients were rated as grade E.Results All 18 patients were followed up for 6 to 49 months (average,35 months).The postoperative Cobb angle ranged from 19° to 38° (average,27°).The average Cobb angle was corrected 49.3°.Neurological complications included spinal cord injury (3 cases) and nerve root injury (15 cases).The reasons of spinal cord injury consisted of sagittal migration of vertebra,spinal stenosis due to operation and iatrogenic cervical spine fracture and dislocation.The reasons of nerve root injury included compression injury (2 cases),malposition of screw (1 case) and excessive drag of nerve root during osteotomy (12 cases).Conclusion Nerve injury is one of the most serious complications of spinal osteotomy in the treatment of kyphosis in ankylosing spondylitis.The incidence of the neurological complications could be obviously reduced by fully decompressing,making patients in a proper surgical position,recognizing the pathological nature of ankylosing spondylitis and avoiding sagittal migration of osteotomy part.

BACKGROUND: A new material of porous carbonated hydroxyapatite cement (PCHC) is discovered using foaming technique.The new material characterizes original solidification and forms porous structure.OBJECTIVE: To investigate the biomechanical effect of PCHC on repairing cancellous bone defect.METHODS: Among 30 New Land rabbits, 25 ones were considered as surgery group, whose bilateral condyles of femur was used to establish bone defect model (5.5 mm diameter and 12 mm depth). PCHC was implanted into the left side, which was considered as the experimental group, and carbonated hydroxyapatite cement (CHC) was implanted into the right side, which was considered as the control group. Another 5 rabbits were used as normal mechanical control group. Both PCHC and CHC were dip in simulated body fluid (SBF) to test mechanical intension. PCHC and CHC were then implanted into muscles of back in the surgery group. Rabbits Were-sacrificed after 2, 4, 8, 12, and 16 weeks postoperatively. Mechanical analysis was tested following intra-bone and intramuscular implantation, and compressive strength was then tested following dipping into SBF.RESULTS AND CONCLUSION: PCHC: Intra-bone mechanical strength was lower at 2 weeks, the lowest at 4 weeks, but then closed to intension of normal cancellated bone at 8 weeks, higher than normal cancellated bone at 12 weeks, and recovered to the level of normal cancellated bone at 16 weeks. CHC: Intra-bone strength was higher than that of PCHC at 2 weeks, decreased at 4 weeks, gradually increased at 8, 12, and 16 weeks, but still lower than intension of normal cancallated bone. Compressive strength of both PCHC and CHC was not changed following dipping in SBF; however, compressive strength was changed remarkably following intramuscular implantation. The results demonstrated that PCHC characterized by immobilization in situ and mechanical supporting. Thus it could be used for one kind of bone substitute material to repair the bone defect.

BACKGROUND: Glucocorticoid-induced osteoporosis has relationship with the down-regulation of osteoprotegedn expression. Osteoprotegerin could inhibit bone resorption in the animal experiment and clinical application for treating oestrogenic hormone deficiency osteoporosis. OBJECTIVE: To investigate the effects of exogenous recombinant osteoprotegerin fusion protein on glucocorticoid-induced osteoporosis in rats. DESIGN, TIME AND SETTING: Randomized grouping, controlled animal expenment was performed in the Institute of Orthopedics, Chinese PLA General Hospital between January 2006 and June 2008. MATERIALS: Sixty healthy male Wistar rats of clean grade; Dexamethasone was produced by Tianjin Jinyao Amino Acid Co., Ltd (Licenca No. H12020515). METHODS: Sixty rats were divided into 3 groups randomly with 20 rats in each. Control group: the rats were administrated with 0.9％ sodium chloride. Dexamethasone group: the rats were administrated with dexamethasone intramuscularly. Osteoprotegedn group: the rats were administrated with dexamethasone and recombinant osteoprotegerin intramuscularly. MAIN OUTCOME MEASURES: All rats were sacrificed at 12 weeks after administration. The urine calcium, phosphor, creatinine, bone mineral density, biomechanics tests of femur and vertebral body, were measured. Immunohistochemistry staining were performed to observe osteoprotegerin expression.RESULTS: Sixty rats were all involved in the final analysis. ①Compared with control group, udne calcium increased in the Dexamethasone group (P < 0.05); the bone mineral density of lumbar vertebra and femur decreased significantly (P < 0.05), especially lumbar vertebra (P < 0.01); biomechanics tests of femur and vertebral body (maximum load, maximum stress, elasticity load, elasticity stress, elastic modulus) decreased significantly (P < 0.05); immunohistochemistry staining showed that endogenous osteoprotegerin expressions were reduced significantly in bone marrow of Dexamethasone group (P < 0.01). ②Compared with Dexamethasone group, urine calcium decreased in the osteoprotegerin group (P < 0.01 ); the bone mineral density of lumbar vertebra and femur increased (P < 0.05); the parameters of biomechanics testa of femur and vertebral body increased (P < 0.05); the osteoprotegerin expression was not changed between Dexamethasone group and osteoprotegerin group.CONCLUSION: Glucocorticoid could inhibit osteoprotegerin expression in the bone followed by progressive bone loss and induce osteoporosis. Recombinant osteoprotegerin works effectively in inhibiting bone resorption after administrated with glucocorticoid, reduce bone resorption index, increase bone mineral index and bone strength, thus improving the osteoporosis which is induced by glucocorticoid.

BACKGROUND: Carbonated hydroxyapatite cement (CHC) s a new kind of biomaterial for bone defect, which is made of powder and fluid, and can be mixed to be pasty to repair various bone defects.OBJECTIVE: To observe the improvement of vertebrae height and pain in patients with osteoporosis vertebral compression fracture (VCF) after vertebroplasty by using a new kind of bone graft biomaterial, taking CHC as the filling material to reinforce the vertebral body.DESIGN: A contrast observation trial taking patients as subjects.SETTING: Department of Orthopaedics, General Hospital of Chinese PLA.PARTICIPANTS: Totally 34 patients with thoracic or lumbar osteoporosis VCF who received the treatment in the Department of Orthopaedics, General Hospital of Chinese PLA between October 2000 and August 2003. Inclusive criteria: ①Definite diagnosis by CT; ② Informed consents were obtained from the patients. Exclusive criteria: The patients with osteoporosis vertebral compression fractures who suffered vertebral posterior wall fracture. There were 6 males and 28 females, and they were aged (72±13)years; Among the patients, 27 were diagnosed as postmenopausal osteoporosis, 1 as cortical hormone-induced osteoporosis and 6 male patients weresenile osteoporosis.METHODS: ①All the patients were randomly divided into two groups: Experimental group (n =23) and control group (n=11). All the patients were performed percutaneous operation with local anesthenia. All cases were performed percutaneous operation under local anesthesia. Under the C-arm monitored, one side pedicle puncture was performed to enter the anterior column of the involved VCF. Patients of the experimental group were filled with CHC. Patients of control group were filled with polymethyl Methacrylate (PMMA) with the same way. ② Referred to McGill-Melzack scoring. Among the scale 0-100 mm (0 was no pain, 100 was acute pain), the value indicated the painful intensity and mental assault degree. ＜ 30 scores indicated good, 30-40 basically satisfied and ≥ 50 poor .③ Referred to the method from Lee et al, the preoperative height (A1) and postoperative height (A2) of compression fracture position of VCF were measured according to the lateral X-ray film. At the same time, the upper vertebral height (A3) and the inferior vertebral height (A4) were measured at the same position. The original height (A) of the involved vertebra was calculated as (A)= (A3+A4)/2,and the preoperative vertebral compression rate =(A-A1 )/A, the postoperative vertebral compression rate =(A-A2)/A, the restoring rate = (the preoperative vertebral compression rate-the postoperative vertebral compression rate)/the preoperative vertebral compression rate. ④ The wounds of the patients were observed after operation. The levels of blood routine, serum calcium and serum phosphorus were detected before, one day and one week after operation. MAIN OUTCOME MEASURES: ① Preoperative and postoperative VAS scoring. ② The vertebral compression rate and restoring rate. ③ Wounds were observed after operation. The blood routine, the serum calcium and serum phosphorus were detected before, one day and one week after operation.RESULTS: Totally 34 patients were involved in the result analysis. ①The preoperative visual analogue scale (VAS) score of experimental group were (91.5±21.7) points, and the postoperative ones were (44.5±27.2) points. The difference of VAS score reduced gradually along with the postoperative time. There was no difference of VAS score between experimental group and the control group 4 weeks after operation. ② The biocompatibility of CHC in the vertebral body was fine. The vertebral compression rate of experimental group was recovered from (43.1±21.4)％ preoperatively to (27.3± 18.5)％ postoperatively. The rate of restored heights was (27.3±18.5)％. ③ All patients obtained Ⅰ stage wound healing, and none of them had infection, inflammatory secretion and nervous symptom. There were no differences in blood routine test, serum calcium, serum phosphorus between patients in two groups. One case filled by PMMA and two cases filled by CHC presented leakage, and none had nervous symptom.CONCLUSION: As the filling materials for vertebropalsty, CHC can restore the vertebral heights and relieve pain safely and effectively, however, its efficacy to relieve pain is not significant as PMMA in the short term.

[Objective]To analysis the unstable pathogeny of the superior cervical congenital deformity for the operative method selection. [Methods]65 patients with congenital superior cervical deformity were treated from January 2003 to June 2007,in which there were 39 male patients,and 26 female patients. The X-ray,CT and MRI were examined generally before operation. In the images,there were 32 cases with formation failure deformity,18 cases with segmentation failure deformity,and 15 cases with abnormal structure deformity. 37 cases with easy reduction and no anterior compression were treated with posterior internal fixation and self cancellous bone graft for fusion. The other 28 cases with impossible reduction and anterior spinal cord compression were treated with anterior odontoid resection and decompression,and then posterior internal fixation and self cancellous bone graft for fusion.[Results]All of the operations were sucesseful without never and vascular injury and other serious complication. There were 47 cases following up 12 to 24 months in the 65 cases,and the mean follow up 15 6 months.One case's broken up titanium rod were treated with replacing new rod and bone graft,and the other cases showing bone fusion. There 28 cases following up in 34 cases with superior cervical pain and resticted movement,in which the pain was decreased or disappeared. There were 19 cases following up in 31 cases with numb limbs and superior never center injury. The preoperative Frankel score showed 5 cases B,8 cases C,and 17 cases D. The postoperative Frankel score of following up cases showd 5 cased C,6 cases D,and 8 cases E,and the score increased one or two degree.[Conclusion]The posterior,or anterior-posterior approach was selected by the condition of congenital superior cervical pathogeny,atlantoaxial reduction and spinal cord compression.