Abstract:Objective To evaluate the risk factors and countermeasures of intradiscal cement leakage due to percutaneous vertebroplasty (PVP). Methods Clinical data of 132 patients (198 vertebrae) with osteoporotic vertebral compression fracture, who underwent CT-guided PVP in Zhongshan Hospital Affiliated to Zhongshan&nbsp;University from January 2013 to June 2014, were analyzed retrospectively. Based on whether there occurred intradiscal cement leakage, the patients were assigned into two groups: control group (97 patients, 163 vertebrae) in which the patients were not found intradiscal cement leakage during or after PVP, and observation group (35 patients, 35 vertebrae) in which patients were suffered from intradiscal cement leakage. Possible related factors such as bone mineral density, the degree of vertebral compression, injection volume of cement, whether the vertebral endplate was normal, and whether the vertebral body pre-existed vacuum cleft sign, were screened by single variate analysis, and then the factors which had statistical significance were investigated by multivariate logistic regression analysis. According to severity of endplate abnormality, as well as whether there had intervertebral cleft sign, types of intradiscal cement leakage were classified into A1, A2 and B, then the imaging characteristics of the discs were evaluated, and the corresponding countermeasures were pointed out. Results Endplate abnormality, cleft sign was found in 12, 2 vertebrae (7.4%, 1.2%) in control group, and 35, 14 vertebrae (100.0%, 40.0%) in observation group accordingly, which showed statistical significance when compared incidence of either endplate abnormality or cleft sign between two groups (P <0.05). Single variate analysis revealed that grouping, bone mineral density and cleft sign were risk factors for endplate abnormality (P <0.05), grouping and endplate abnormality were risk factors for cleft sign (P <0.05); Multivariate analysis indicated that endplate abnormality and cleft sign were all risk factors for intradiscal cement leakage (P <0.05), in which the risk of endplate abnormality in observation group was 378.977 times compared to control group, and the risk of cleft sign in observation group was 15.483 times as high as that in control group. MRI results in observation group showed that there were signal interruption area on the endplate where had cleft interlinked to damaged vertebral body, and the direction of the cleft was consistent with the direction of bone cement leakage;A1-, A2-and B-type intradiscal cement leakage was in 11, 18 and 6 vertebrae, and the percentage of bone cement leakage to upper vertebral body was 77% (27/35) and to lower vertebral body was 23% (8/35). Conclusions Abnormal vertebral endplate (signal interruption with cracks in the interruption interlinked to damaged vertebral body) and intravertebral cleft sign are high-risk factors of intradiscal bone cement leakage. Individual treatment should be recommended according to severity of endplate abnormality, whether there pre-existed intravertebral cleft sign, as well as the direction of bone cement leakage.

Abstract:Objective To evaluate the effect of different distributions of quantitative bone cement on improving total stiffness of osteoporotic vertebrae after bone cement augmentation by finite element (FE) analysis. Methods We choose a female cadaver and then three-dimensional FE models of the osteoporotic L1 vertebral body (VB) were built. Bone cement augmentation of L1 was simulated in this numerical study. VBs <br> were divided into five groups based on the volume and distribution of bone cement: Group A (4.5 mL), the cement augmentation was limited to hemivertebral bodies; Group B (4.5 mL), the cement augmentation was located in the middle and symmetrically reached one quarter of both sides of the VB; Group C (4.5 mL), the bone cement was located in the middle and symmetrically reached half of both sides of the VB; Group D (4.5 mL), the cement augmentation was located in the middle and symmetrically reached three quarters of both sides of the VB; Group E (9 mL), bi-pedicular bone cement augmentation. Changes of total stiffness in all models with cement augmentation were compared with those in the corresponding unaugmented models, and the differences of total stiffness among the different groups were evaluated under axial compression loads. Results The total stiffness of VBs of each group was markedly increased compared with the osteoporotic, untreated model (P <0.05). The total stiffness of group E was significantly higher than group A, C and D, respectively (P<0.05), and there was no significant difference between group B and E (P >0.05). Moreover, the total stiffness of group B was 33.9%, 27.2% and 34.1% higher than group A, C and D, respectively (P <0.05), and there were no significant differences among group A, C and D (P >0.05). Conclusion When bone cement is being quantified, the total stiffness of osteoporotic VB improved by cement distribution in the middle of the VB is superior to uni-pedicular or symmetrically diffused cement distribution.

Abstract:Tantalum has attracted much attention due to its excellent corrosion resistance and biocompatibility. However, the relative high cost of material has dramatically restricted its clinical application as biomaterial. Therefore, various coating fabrication methods have been used to reduce the cost. In this paper, the biological advantages of tantalum, current situation of the fabrication of tantalum coating on stainless steel, titanium alloy, as well as cobalt-chromium alloy, and the prospects of tantalum clinical applications were summarized.

Abstract:Objective To evaluate and compare the safety and reliability of posterior cervical single open-door laminoplasty using ultrasonic bone curette versus high-speed drill. Methods From October 2014 to December 2015, thirty-two patients with cervical spinal stenosis underwent posterior cervical single open-door laminoplasty by either using ultrasonic bone curette (n = 11) or high-speed drill (n = 21) in Nanfang Hospital affiliated to Southern Medical University, their data were collected and analyzed retrospectively. The segments,&nbsp;operation time, intraoperative estimate blood loss, postoperative drainage, Japanese Orthopaedic Association (JOA) scores, rate of the improved JOA score and incidence of complications were compared between ultrasonic bone curette and high-speed drill groups. Results The operation time and intraoperative estimate blood loss was (150 ± 22) min, (191 ± 116) mL in ultrasonic bone curette group, and (169 ± 35) min, (216 ± 123) mL in high-speed drill group respectively, both showing no significant differences between two groups (P >0.05). Postoperative drainage of ultrasonic bone curette group was better than that of high-speed drill group [(164 ± 84) vs (236 ± 93 ) mL, P <0.05]. The postoperative neurological function of both groups were well improved compared to preoperative ones (P <0.05), but there were no statistical differences of postoperative JOA scores, JOA scoring improvement rate as well as excellent and good rate of JOA scoring improvement between two groups (P >0.05). One patient had dural tear in ultrasonic bone curette group, no patients suffered from leakage of cerebrospinal fluid or wound infection in two groups. Conclusion When compared to high-speed drill, usage of ultrasonic bone curette could obtain similar safety and effectiveness during posterior cervical single open-door laminoplasty, which is relatively more efficient with less postoperative drainage.

Abstract:Objectives To evaluate the bony fusion effects of posterior C1-C2 screw-rods fixation with different bone graft materials for patients with atlantoaxial dislocation (AAD). Methods Under general anesthesia, 468 patients with reducible AAD treated in Guangzhou General Hospital of Guangzhou Military Command from November 2002 to July 2012, performed posterior C1-C2 screw-rods fixation which C1 screw&nbsp;fixation methods including pedicle screw, partial transpedicle screw or lateral mass screw fixation, and C2 screw fixation methods including pedicle screw, translaminar screw, pars screw or lateral mass screw fixation. Bone grafts were chosen as autogenous cancellous bone, allogeneic cancellous bone, and autogenous bone marrow plus allogeneic cancellous bone. The fusion was followed up by X-ray and CT scanning images. Results All 468 cases underwent the surgery successfully, and no neurovascular injuries were found during the operation. There were 2 cases of superficial wound infection which were cured after debridement and antibiotics treatment. Radiological results showed all patients achieved satisfactory reduction. Total of 447 patients were followed up for 3-72 months with an average of 39 months. Among them, autogenous cancellous bone graft were used in 405 patients, allogeneic cancellous bone graft in 27 patients, and autogenous bone marrow plus allogeneic cancellous bone in 15 patients. Clinical symptoms were found to be improved to some extent without broken screw-rods in all patients. With screw loosening, a total of 5 patients did not achieve fusion (including autogenous bone grafting in 2 patients and allogeneic bone grafting in 3 patients). One of them without atlantoaxial instability was still wearing brace and following up continuously, the other four cases were reoperated with enough autogenous cancellous bone graft and achieved solid bony fusion later. Conclusions Autogenous bone should be used in the first and revision operation for patients with AAD; When it was forced to use allogeneic cancellous bone, adding autologous bone marrow can increase bony fusion rate.

Abstract:Objective To investigate the clinical effects of two kinds of surgical exposures for complicated&nbsp;pelvic and acetabular fractures by pararectus versus ilioinguinal approach. Methods Clinical data of 25 patients with complex pelvic and acetabular fractures treated in Central People's Hospital of Zhanjiang and People's Hospital of Lianjiang from January 2013 to January 2015, were retrospectively analyzed. Those patients were divided into two groups, 12 in pararectus approach group and 13 in ilioinguinal approach group. Length of incision, operation time, estimate blood loss, hospital stay and postoperative complications were recorded, postoperative fracture reduction was evaluated by radiological examination (X-ray, CT scanning, etc.), hip joint functions 6 months after surgery was assessed according to Harris hip joint function scoring standard. The clinical parameters were compared between two groups. Results All patients were followed up, with the average follow-up time of 12.5 months (12-14 months). Length of incision, operation time, estimate blood loss and hospital stay in these two groups (pararectus versus ilioinguinal) were (5.0 ± 1.2) cm, (224 ± 40) min, (136 ± 22) mL, (17.3 ± 0.7) d and (13.5 ± 2.7) cm, (272 ± 39) min, (396 ± 42) mL, (19.4 ± 0.7) d respectively, satisfaction degree of fracture reduction, excellent and good rate of Harris scoring and incidence of postoperative complications were 11/12, 12/12, 1/12 and 9/13, 8/13, 5/13 respectively. Length of incision, operation time, estimate blood loss, hospital stay and the excellent and good rate of Harris scoring in pararectus approach group were superior than those in ilioinguinal groups, the differences between two groups were statistically significant (P <0.05), while the differences of satisfaction degree of fracture reduction, and incidence of postoperative complications had no statistical significance between two groups (P>0.05). Conclusions Pararectus approach is a good choice for complex pelvic and acetabular fractures, because it could provide good exposure to pelvic and acetabular anatomic structures such as quadrilateral area, corona mortis, which is helpful for fracture reduction and fixation, shorten length of incision, reduce blood loss and improve hip joint function significantly.

Abstract:Objective To evaluate the validity and reliability of a Chinese version of neck pain and disability scale (NPAD). Methods NPAD was translated into Chinese (SC-NPAD) and tested in the outpatient service of orthopaedic department in Changhai Hospital affiliated to the Second Military Medical University. From May 2008 to March 2009, total of 117 patients were involved and 106 (90.1%) of them completed the first questionnaire. Five to seven days later, 36 cases were randomly chosen for the second questionnaire and 35 patients completed. Reliability assessment was determined by calculating internal consistency and repeatability. At the same time, SF-36 scale (SF-36) was distributed for comparison, also, correlation analysis was used to determine the relationship between SC-NPAD and SF-36. Results Factor analyses demonstrated that the internal consistency of the four subscales for NPAD including "pain", "disability", "neck-specific function" and"emotional and cognitive influences" subscales, was 0.935, 0.952, 0.955 and 0.910, respectively, with a consistent&nbsp;test-retest reliability (r = 0.813, P = 0.000). All the subscales were significantly correlated with SF-36 and five SF-36 domains associated with the items of physical functioning, social functioning, role-physical, vitality and bodily pain. Conclusion SC-NPAD has good reliability and validity, which is fit for assessments for Chinese neck pain patients.

Abstract:Treatment of chronic osteomyelitis is difficult in the field of orthopaedic trauma surgery, with long therapy course, poor clinical results and high amputation rate. In recent years, limb salvage has gradually become a research hotspot. In this paper, present situation and progress in limb salvage therapy for chronic osteomyelitis were reviewed, involving the aspects of debridement, treatment of bone defect, soft tissue coverage, stabilization of affected bone, antibiotic treatment and adjuvant therapy.