Objective To discuss the application of mobile C-arm CT scan in the operations for thoracolumbar burst fractures of type A3.Methods From January 2012 to December 2014,21 patients with single-segment thoracolumbar burst fracture (AO type A3) were treated.They were 15 males and 6 females,aged from 17 to 68 years (average,43.6 years).By the American Spinal Injury Association (ASIA) grading,one was grade A,2 were grade B,12 grade C,4 grade D and 2 grade E.Preoperative CT examination was conducted.Mobile C-arm CT scan was performed to evaluate reduction of the fragments after the fracture was reset by posterior pedicle screwing.Laminotomy for canal decompression or reduction of the fragments would be performed if it was indicated by the results of mobile C-arm CT scan.CT examination was conducted postoperatively to assess the fracture reduction and recovery of the canal calibre.Results All the patients were followed up for an average of 15.5 months (from 10 to 18 months).Their cobb angle,vertebral anterior margin compression rate,spinal occupancy rate,vertebral translocation rate and visual analogue score at postoperation and final follow-up were significantly improved compared with their preoperative values (P ＜ 0.05),but there were no significant differences between postoperation and final follow-up in all the above indexes (P ＞ 0.05).Postoperative ASIA grading showed that the spinal function was improved from grade B to grade C in one,from grade C to grade D in 4 cases,from grade C to grade E in 5 cases,and from grade D to grade E in 3 cases.Conclusion Since intraoperative C-arm CT scan can help decide whether laminectomy for canal decompression is conducted or not in the surgery of thoracolumbar burst fractures,it enhances the surgical safety and reliability.

Lumbar degenerative disease is one of the most common diseases in orthopaedic clinics, and the chronic low back pain caused by it seriously affects patients' living quality. Currently, intervertebral fusion and rigid fixation are the main surgical methods for lumbar degenerative disease. Although the intervertebral fusion and rigid fixation can achieve a higher fusion rate, due to the stress concentration of adjacent segments, the adjacent segment degeneration may occur and make the patient's satisfaction rate much lower than the imaging fusion rate. Dynamic fixation is a new fixing concept, which can control the abnormal motion of the spine segment while retaining part of the movement of the fixed segment. Moreover, dynamic fixation is also beneficial to reduce the degeneration of adjacent segments and the incidence of breakage of internal fixation. Nowadays, various lumbar transpedicular dynamic fixation systems have appeared on the market. Most of these transpedicular dynamic fixation systems are derived from the design of pedicle screws and rods used in spinal fusion surgery in the 1980 s and 1990 s. The original intention of their design is to stabilize the abnormal segments and reduce the pressure on degenerated intervertebral discs and facet joints, while maintaining the normal movement of relevant segments. By reviewing the biomechanical research, clinical efficacy, existing problems and advantages and disadvantages of common backward lumbar transpedicular dynamic fixation systems, this article intends to provide new ideas for the improvement of the backward lumbar transpedicular dynamic fixation system design, as well as offering surgical treatment strategies for clinicians.

Objective To investigate the effect of ica operon on adherence and biofilm formation of Staphylococcus epidermidis(S.epidermidis)at orthopedic implants,and to provide theoretical basis for the use of clinical orthopedic materials.Methods The icaADBC genes of S.epidermidis were amplified by PCR.The expression of ica genes was detected by fluorescence quantitative PCR.The contents of polysaccharide intercellular adhesion (PIA) were determined by phenol-sulfuric acid method.The ability of bacterial adherence was detected by colony counting method and the ability of biofilm formation was measured by crystal violet staining method.Results The icaADBC genes were presented and expressed in eleven S.epidermidis strains.The strains with high icaABDC gene expression had higher PIA product.S.epidermidis isolates had the strongest adherence and biofilm formation ability on bone material,followed by titanium and stainless steel.The expression of icaA gene correlated with the biofilm formation of bacteria on three biomaterials.Conclusion S.epidermidis isolates had the different adherence and biofilm formation on different biomaterial implants.Ica gene regulates the biofilm formation of S.epidermidis by regulating the expression of PIA.

Hip arthroscopy has become a routine treatment for the localized hip lesions.With the rapid development of arthroscopy,the number of surgeries has increased greatly.Though hip arthroscopy is considered as low risk operation,its complications have been constantly reported and noted.There are two major types in hip arthroscopy surgeries:conventional operative complications and special complications.Conventional operative complications include venous thromboembolism,hemorrhage,and pain.Special complications are associated with arthroscopic techniques and local anatomical structures of the hip,such as the perineal nerve,the lateral femoral cutaneous nerve,the acetabular labium or the iatrogenic injury of the cartilage surface of the femoral head.Hip arthroscopy has obvious advantages such as small surgical wound and rapid recovery,but its complications can not be ignored.Joint surgeons must fully recognize it and keep vigilant so as to avoid complications as much as possible.This review will systematically elaborate the complications of hip arthroscopic surgery from general and special aspects so as to provide ideas for reducing the occurrence of complications in hip arthroscopic surgery.

Objective To evaluate the efficacy and safety of non-steroidal anti-inflammatory drugs (NSAIDs) in preventing heterotopic ossification after hip arthroscopy.Methods Literature search was conducted in PubMed,Embase,Cochrane Library,CNKI and Wanfang data with time range from January 1973 to November 2017.Clinical case control articles on NSAIDs in preventing heterotopic ossification after hip arthroscopy were screened based on the inclusion and exclusion criteria.Meta analysis was done using RevMan 5.3 software to investigate the incidence of complications such as heterotopic ossification and gastrointestinal bleeding after hip arthroscopy in patients taking NSAIDs orally.Results Six articles were included in the study,with a total of 754 cases and 536 controls.NSAIDs reduced the incidence of heterotopic ossification after hip arthroscopy (RR =0.09,95％ CI 0.03-0.27,P ＜ 0.05).Selective COX-2 inhibitor celecoxib (RR =0.17,95％ CI 0.03-0.91,P ＜ 0.05) and PG synthase inhibitor of naproxen (RR =0.17,95％ CI 0.09-0.32,P ＜ 0.05) were also effective in preventing heterotopic ossification.There was no significant difference in the incidence of gastrointestinal complications between the cases and controls after NSAIDs prophylaxis (RR =2.17,95％ CI 0.92-5.12,P ＞ 0.05).Conclusion NSAIDs can effectively reduce the incidence of heterotopic ossification after hip arthroscopy and does not increase the incidence of postoperative gastrointestinal complications.Therefore,it is effective and safe to use NSAIDs to prevent the occurrence of heterotopic ossification after hip arthroscopy.

Venous thromboembolism (VTE) is a common complication of hip and knee arthroplasty and of many major orthopedic surgeries.VTE mainly includes two aspects,ie,deep vein thrombosis (DVT) and pulmonary embolism (PE).Symptomatic PE is likely to endanger patients' life,resulting in irreversible severe consequences.With the return of venous blood,DVT may also fall off at any time,forming a new PE.Therefore,the prevention of VTE in large orthopedic surgeries has been highly valued by scholars worldwide.However,the problem of VTE after arthroscopic surgery has not drawn much attention from clinicians.Researchers have not reached a consensus on whether routine anticoagulation therapy is required after surgery because of VTE's low incidence and discrepancy among various studies (0.42％-17.9％).With a large number of knee arthroscopy being performed per year,the postoperative VTE incidence can not be ignored.For these reasons,some scholars have suggested that patients after knee arthroscopy should be stratified and that patients with a higher risk of postoperative VTE need to be given anticoagulant therapy.Risk factors for VTE after knee arthroscopy may have effects on the clinical treatment of patients.Therefore,a review of the literature to explore the possible risk factors for postoperative VTE was conducted.

Objective To investigate the clinical therapeutic effects of bone cement-augmented pedicle screw fixation for cement vertebrae refractures with lower limb neurological symptoms after percutaneous kyphoplasty (PKP) in elderly patients with osteoporotic thoracolumbar compression fractures.Methods A total of 123 elderly patients with osteoporotic thoracolumbar compression fractures underwent PKP from December 2013 to December 2016 were retrospectively analyzed by case series study.Twelve patients had vertebral refracture with compression of the spinal cord or cauda equina which resulted in lumbosacral and leg pain,numbness and disability of ambulation and there were five males and seven females,with age of (69.2 ± 7.1) years.Injured vertebrae was located at T12 in five cases,at L1 in five and at L2 in two.Bone cement-augmented pedicle screw fixation through a standard posterior approach was utilized to treat all the 12 patients.Visual analogue scale (VAS),Oswestry disability index (ODI),anterior vertebral height compression ratio,and kyphotic angle at the preoperative time,one week postoperatively and last follow-up were recorded and compared.Intraoperative and postoperative complications were also recorded.Results The mean duration of follow-up in all the patients was 26.7 months (range,12-36 months).Intraoperative nerve injury,dural tear,leakage of bone cement,bone cement toxicity reaction,and pulmonary embolism were not observed during the surgery.The postoperative radiographs for all the 12 patients showed that the bone cement was distributed in cancellous bone and around the screw appropriately where there was no cement leakage out of the vertebral body or pedicle.Compared with preoperative scores,the average low back pain VAS,leg pain VAS and ODI at postoperative one week were improved by (2.2 ± 0.7) points,(2.2 ± 0.4) points and (33.2 ± 8.9) points,respectively (P ＜ 0.01).Anterior vertebral height compression ratio was decreased from preoperative (71.5 ± 11.7) ％ to (18.7 ± 10.3) ％ at postoperative one week (P ＜ 0.01).The mean kyphotic angle was corrected from preoperative (28.3 ± 7.6) ° to (7.1 ± 2.3) ° at postoperative one week (P ＜ 0.01).The symptoms of lumbar pain,and numbness and weakness of lower limbs were improved significantly.There was no statistically significant difference of all the parameters between the last follow-up evaluation and one week post-operatively (P ＞ 0.05).Conclusion For elderly patients with spinal cord or cauda equina nerve compression symptoms after PKP for osteoporotic thoracolumbar compression fractures,the usage of posterior approach bone cement-augmented pedicle screw fixation can effectively correct kyphosis,relieve neurological symptoms and restore spinal stability.