Yunsheng Ou

A hollow cylindrical nano-hydroxyapatite/polyamide composite strut for cervical reconstruction after cervical corpectomy☆

This retrospective study included 35 patients who had a nano-hydroxyapatite/polyamide (n-HA/PA) composite strut implanted for cervical reconstruction and fusion after corpectomy from 2006 to 2008. The average follow-up period was 38.5 months (range: 24-48 months). The Japanese Orthopedic Association score and visual analog pain scale score were significantly improved and maintained to the last follow-up. The cervical curvature and the height of fused segments were also corrected significantly and retained to the last follow-up. A total of 94.3% of patients had achieved radiographic bony fusion at the postoperative 24-month follow-up. One patient presented with subsidence of the n-HA/PA composite strut and dislodgement of the screws, but the patient had no discomfort and no additional surgery was needed. We conclude that the n-HA/PA composite strut is scientifically and technically sound for cervical reconstruction and interbody fusion after corpectomy with anterior plate fixation.

Selective COX-2 inhibitor ameliorates osteoarthritis by repressing apoptosis of chondrocyte

Summary Background Celecoxib has a positive effect on human osteoarthritic cartilage, but the mechanisms remain unclear. The aim of this study was to test whether celecoxib could inhibit the apoptosis of chondrocyte and ameliorate type II collagen synthesis to relieve symptoms of OA (osteoarthritis). Material/Methods 130 Wistar rats were randomly divided into 4 groups as celecoxib (CE), ibuprofen (IBP), indomethacin (IN) and normal saline group (NS). The osteoarthritis was induced by the excision of the left Achilles tendon. At the 3th, 6th, 9th month of treatment, the histological structure of articular cartilage was observed using HE staining. Type II collagen was examined using immunohistochemistry. Chondrocyte apoptosis was detected by TUNEL staining, and the change of ultra-microstructure of chondrocyte was examined through a transmission electron microscope. Results CE reduced the OA-like histological changes and suppressed chondrocyte apoptosis. However, IN or IBP had deleterious effects on articular cartilage and enhanced the chondrocyte apoptosis. IBP promoted the expression of type II collagen, and IN inhibited its expression, but had no effect in the CE group. Conclusions CE had favorable action on OA progression, and may be the ideal choice in the treatment of chronic destructive joint disease where anti-inflammatory drugs need to be used for a prolonged period.

Insulin with Chondroitinase ABC Treats the Rat Model of Acute Spinal Cord Injury

Traumatic brain injury is often associated with acute spinal cord injury (ASCI). Insulin and chondroitinase ABC (ChABC) are both therapeutically effective, but the combined therapeutic effect of insulin and ChABC is still not clear. A combination of insulin and ChABC were used to treat a rat model of ASCI. This combination therapy prevented neuronal cell death by improving motor function, increasing cell growth and inhibiting cell apoptosis in ASCI rats. Expression of growth-associated protein 43, a marker of axonal re-growth, increased after combined treatment with insulin and ChABC. These results may provide a basis for a future method of treating ASCI.

Tranexamic acid reduces perioperative blood loss of posterior lumbar surgery for stenosis or spondylolisthesis: A randomized trial

Background: A prospective, randomized, double-blind, placebo-controlled study was performed. The routine usage of TA in spinal surgery is controversial. Only a few studies have focused on patients undergoing posterior lumbar surgery for stenosis or spondylolisthesis, although a large clinical cohort exists in the population. This study aimed to evaluate the effect and safety of TA in reducing perioperative blood loss in posterior lumbar surgery for stenosis or spondylolisthesis. Methods: 100 eligible patients out of 126 were randomized to receive either a bolus dose of 30 mg/kg TA i.v, a maintenance dosage of 2 mg/kg/h TA, or an equivalent volume of normal saline. The pedicle screw system was used for fixing in all the patients, followed by decompression and posterior lumbar interbody fusion. The primary outcomes were intraoperative estimated blood loss and total blood loss. The secondary outcomes were receiving packed red blood cells and postoperative hemoglobin and hematocrit levels. Results: In total, 4 patients were excluded from the analyses, 50 patients were in the TA group, and 46 in the placebo group. The demographic and baseline data between the groups were not statistically different. The intraoperative estimated blood loss and the total blood loss were 33% and 41% lower in the TA group than the placebo group, respectively. The blood transfusion rate did not vary significantly (P = 0.191). Except a patient with a dural tear in the placebo group, no other complications were observed. Conclusion: TA significantly reduced the perioperative blood loss in patients undergoing posterior lumbar surgery for stenosis or spondylolisthesis.

Functionalized d-form self-assembling peptide hydrogels for bone regeneration.

Bone defects are very common in orthopedics, and there is great need to develop suitable bone grafts for transplantation in vivo. However, current bone grafts still encounter some limitations, including limited availability, immune rejection, poor osteoinduction and osteoconduction, poor biocompatibility and degradation properties, etc. Self-assembling peptide nanofiber scaffolds have emerged as an important substrate for cell culture and bone regeneration. We report on the structural features (eg, Congo red staining, circular dichroism spectroscopy, transmission electron microscopy, and rheometry assays) and osteogenic ability of d-RADA16-RGD peptide hydrogels (with or without basic fibroblast growth factor) due to the better stability of peptide bonds formed by these peptides compared with those formed by l-form peptides, and use them to fill the femoral condyle defect of Sprague Dawley rat model. The bone morphology change, two-dimensional reconstructions using microcomputed tomography, quantification of the microcomputed tomography analyses as well as histological analyses have demonstrated that RGD-modified d-form peptide scaffolds are able to enhance extensive bone regeneration.

In vitro evaluation of antibacterial activity and cytotoxicity of novel nanocomposite material for bone filling

Abstract In this study, silver ion substituted nanohydroxyapatite, titania nanoparticles and polyamide 66 composite bone filling materials were prepared, which were expected to be a suitable bone repair material with good antibacterial activity, biocompatibility and osteoconductivity, for use in osteomyelitis surgery. The antibacterial activity and release of Ag ions in vitro were evaluated. Two types of bacteria strains, Staphylococcus aureus and Escherichia coli were used in this test. The results showed that the composite materials exhibited significant antibacterial effects on the two bacteria. Time course release testing of Ag ions from the composite materials on immersion in simulated body fluid showed pronounced Ag release in the first several days after immersion, and then the release speed slowed down after 14 days. International standard ISO 10993‐12:2007 was adopted for cytotoxicity evaluation using fibroblast cell line L929, and it was found that the cytotoxicities for the composite materials ranked are all within 1, which showed no cytotoxicity for the composite materials.

Comparison between titanium mesh and autogenous iliac bone graft to restore vertebral height through posterior approach for the treatment of thoracic and lumbar spinal tuberculosis

Object To compare the clinical efficacy of titanium mesh cages and autogenous iliac bone graft to restore vertebral height through posterior approach in patients with thoracic and lumbar spinal tuberculosis. Method 59 patients with spinal tuberculosis underwent interbody fusion and internal fixation through posterior approach in our department from January 2011 to December 2013. In group A, 34 patients obtained titanium mesh for the reconstruction of vertebral height, among them 25 patients (group A1) suffered from single-segment spinal tuberculosis, and 9 patients, (group A2) had multi-segment spinal tuberculosis. In group B, 25 patients got autogenous iliac bone graft to restore vertebral height, including 24 patients with single-segment spinal tuberculosis (group B1), and 1 patient with multi-segment spinal tuberculosis (group B2). The clinical efficacy was evaluated based on average operation time, blood loss, hospital stays, hospitalization expenses, visual analog scale (VAS), Oswestry Disability Index (ODI), erythrocyte sedimentation rate (ESR), C-Reactive protein (CRP), neurological function recovery, bony fusion, intervertebral height, Cobb angle and postoperative complications. Results Final follow-up time was an average of 35.5 months ranging from 15 to 56 months. All patients were completely cured and obtained solid bone fusion. The bony fusion time was 9.4±6.1 months in group A1, 10.2±2.7 months in group A2 and 8.7±3.6 months in group B1. There were no significant difference among three groups (P>0.05). The Cobb correction and restoration of intervertebral height significantly improved compared with those in preoperation, but without significant difference among three groups (P>0.05). The loss of angular correction and intervertebral height in group A1 were found to be less than those in group B1 (P<0.05), but with no significant difference between group A1 and group A2, and between group A2 and group B1 (P>0.05). Patients in group B1 got the most loss of angular correction and intervertebral height. In addition, neurological function was revealed to be significantly improved after surgery. There were significant differences of VAS, ODI, ESR and CRP between preoperation and postoperation at the final follow-up time (P<0.05), with no significant difference among three groups (P>0.05). No statistically significant difference was found when analyzing blood loss, hospital stays, hospitalization expenses, and corrective cost among three groups (P>0.05). Complications included cerebrospinal fluid leakage (2 cases in group A1 and group A2), sinus formation (3 cases in group A1, group A2 and group B1), and intervertebral infection (1 case in group B1), but no implant failure or donor site complications was found in any patient. Conclusions Titanium mesh cages could obtain good clinical efficacy comparable to autogenous iliac bone graft when treating single-segment spinal tuberculosis, and may be better than autogenous iliac bone graft for treating multi-segment spinal tuberculosis.

Designer bFGF-incorporated d-form self-assembly peptide nanofiber scaffolds to promote bone repair

d-Form and l-form peptide nanofiber scaffolds can spontaneously form stable β-sheet secondary structures and nanofiber hydrogel scaffolds, and hold some promise in hemostasis and wound healing. We report here on the synthetic self-assembling peptide d-RADA16 and l-RADA16 are both found to produce stable β-sheet secondary structure and nanofiber hydrogel scaffolds based on circular dichroism (CD) spectroscopy, transmission electron microscopy (TEM) and rheology analysis etc. d-RADA16 hydrogel and l-RADA16 hydrogel can enhance obvious bone repair in femoral condyle defects of the Sprague-Dawley (SD) rat model compared to PBS treatment. Based on micro-computed tomography (CT), it was revealed that d-RADA16 hydrogel and l-RADA16 hydrogel were capable to obtain the extensive bone healing. Histological evaluation also found that these two hydrogels facilitate the presence of more mature bone tissue within the femoral condyle defects. Additionally, d-RADA16 hydrogel showed some potential in storing and releasing basic-fibroblast growth factor (bFGF) which was able to further promote bone regeneration based on micro-CT analysis. These results indicate that d-form peptide nanofiber hydrogel have some special capacity for bone repair.

Comparison of osteotomy versus non-osteotomy approach for congenital scoliosis: a retrospective study of three surgical techniques

Currently, there are many reports about congenital scoliosis (CS) treatment, but there are still controversies existing with respect to selecting its surgical methods.

Single-Stage Posterior Instrumentation and Unilateral Transpedicular Debridement for the Treatment of Thoracolumbar Tuberculosis: Three Years of Follow-Up

OBJECTIVE The present study compared the efficacy and safety of single-stage posterior instrumentation and unilateral transpedicular debridement with the traditional posterior operation for the treatment of thoracolumbar tuberculosis. METHODS Of the 97 included patients, 53 had undergone posterior unilateral transpedicular debridement and pedicle screw fixation (group A) and 44 had undergone the traditional posterior operation (group B). We compared the outcomes, including correction of kyphosis (Cobb angle), bone fusion rate, visual analog scale score, Frankel classification, and short-form 12-item health survey between the 2 groups. RESULTS All patients obtained intervertebral bone fusion. The mean interval to bone graft fusion was 4.1 months (range, 3-8 months). The patients in the 2 groups showed significant improvement in kyphosis correction, short-form 12-item health survey score, and nerve function. In addition, single-stage posterior instrumentation and unilateral transpedicular debridement resulted in comparable clinical outcomes for the treatment of thoracolumbar tuberculosis. However, the patients experienced less trauma, greater spinal stability, and better functional recovery compared with the traditional posterior operation group. CONCLUSIONS Our results suggest that single-stage posterior instrumentation and unilateral transpedicular debridement can be considered an effective and safe therapy for spinal tuberculosis with single-level and/or bi-level segments.