Biosafety of the Novel Vancomycin-loaded Bone-like Hydroxyapatite/Poly-amino Acid Bony Scaffold / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recently, local sustained-release antibiotics systems have been developed because they can increase local foci of concentrated antibiotics without increasing the plasma concentration, and thereby effectively decrease any systemic toxicity and side effects. A vancomycin-loaded bone-like hydroxyapatite/poly-amino acid (V-BHA/PAA) bony scaffold was successfully fabricated with vancomycin-loaded poly lactic-co-glycolic acid microspheres and BHA/PAA, which was demonstrated to exhibit both porosity and perfect biodegradability. The aim of this study was to systematically evaluate the biosafety of this novel scaffold by conducting toxicity tests in vitro and in vivo.</p><p><b>METHODS</b>According to the ISO rules for medical implant biosafety, for in vitro tests, the scaffold was incubated with L929 fibroblasts or rabbit noncoagulant blood, with simultaneous creation of positive control and negative control groups. The growth condition of L929 cells and hemolytic ratio were respectively evaluated after various incubation periods. For in vivo tests, a chronic osteomyelitis model involving the right proximal tibia of New Zealand white rabbits was established. After bacterial identification, the drug-loaded scaffold, drug-unloaded BHA/PAA, and poly (methyl methacrylate) were implanted, and a blank control group was also set up. Subsequently, the in vivo blood drug concentrations were measured, and the kidney and liver functions were evaluated.</p><p><b>RESULTS</b>In the in vitro tests, the cytotoxicity grades of V-BHA/PAA and BHA/PAA-based on the relative growth rate were all below 1. The hemolysis ratios of V-BHA/PAA and BHA/PAA were 2.27% and 1.42%, respectively, both below 5%. In the in vivo tests, the blood concentration of vancomycin after implantation of V-BHA/PAA was measured at far below its toxic concentration (60 mg/L), and the function and histomorphology of the liver and kidney were all normal.</p><p><b>CONCLUSION</b>According to ISO standards, the V-BHA/PAA scaffold is considered to have sufficient safety for clinical utilization.</p>

Novel application of vacuum sealing drainage with continuous irrigation of potassium permanganate for managing infective wounds of gas gangrene / 华中科技大学学报（医学）（英德文版）

Traumatic gas gangrene is a fatal infection mainly caused by Clostridium perfringens. It is a challenge to manage gas gangrene in open wounds and control infection after debridement or amputation. The aim of the present study was to use vacuum sealing drainage (VSD) with continuous irrigation of potassium permanganate to manage infective wounds of gas gangrene and observe its clinical efficacy. A total of 48 patients with open traumatic gas gangrene infection were included in this study. Amputations were done for 27 patients, and limb salvage procedures were performed for the others. After amputation or aggressive debridement, the VSD system, including polyvinyl alcohol (PVA) foam dressing and polyurethane (PU) film, with continuous irrigation of 1:5000 potassium permanganate solutions, was applied to the wounds. During the follow-up, all the patients healed without recurrence within 8-18 months. There were four complications. Cardiac arrest during amputation surgery occurred in one patient who suffered from severe septic shock. Emergent resuscitation was performed and the patient returned to stable condition. One patient suffered from mixed infection of Staphylococcal aureus, and a second-stage debridement was performed. One patient suffered from severe pain of the limb after the debridement. Exploratory operation was done and the possible reason was trauma of a local peripheral nerve. Three cases of crush syndrome had dialysis treatment for concomitant renal failure. In conclusion, VSD can convert open wound to closed wound, and evacuate necrotic tissues. Furthermore, potassium permanganate solutions help eliminate anaerobic microenvironment and achieve good therapeutic effect on gas gangrene and mixed infection. VSD with continuous irrigation of potassium permanganate is a novel, simple and feasible alternative for severe traumatic open wounds with gas gangrene infection.

Self-made Kirschner wire hook for the treatment of severe displaced proximal humeral fractures in children / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical efficacy of self-made Kirschner wire hook in the treatment of severely displaced proximal humerus fractures in children.</p><p><b>METHODS</b>From January 2007 to February 2012,35 children with severely displaced proximal humerus fractures were treated with self-made Kirschner wire hook fixation,including 25 boys and 10 girls with an average age of 13.2 years old ranging from 5 to 17. The duration from injury to operation was 1 to 10 days with an average of 4.5 days. Preoperative diagnoses were confirmed by X-ray films as type III in 26 cases and type IV in 9 according to the Neer-Horwitz classification of the proximal humerus fractures. All fractures were close fracture without nerve or vascular injuries. Anatomical reduction was achieved by open reduction and the fractures were fixed by self-made Kirschner wire hook. Intra-operative and postoperative complications, postoperative radiographic examination, upper extremity length and range of shoulder motion were observed and recorded. Neer score system was used to evaluate shoulder function.</p><p><b>RESULTS</b>All patients were followed up from 6 to 18 months with an average of 12.1 months. The mean Neer score of the injured side was 94.2 +/- 4.8 (ranged, 84 to 99), 30 patients got an excellent result and 5 good according to the Neer scores. The X-ray showed all the fractures healed without shortening deformity or epiphyseal arrest at early stage. There were no complications related to the implant including loosening or breakage of the self-made Kirschner wire hook. The range of shoulder motion in the injuried side was similar to the normal side, except in abductor lift. All the patients could participate in normal physical activities.</p><p><b>CONCLUSION</b>The method of open reduction and fixed with self-made Kirschner wire hook is a safe,effective,convenient treatment for severely displaced proximal humeral fractures in children.</p>

Deproteinized bone with VEGF gene transfer to facilitate the repair of early avascular necrosis of femoral head of rabbit / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore a new method for early avascular necrosis of femoral head (AVNFH) therapy.</p><p><b>METHODS</b>Sixty-nine AVNFH New Zealand adult rabbits were randomly divided into three groups with equal number. In Group A, deproteinized bone (DPB) that absorbed with recombinant plasmid pcDNA3.1-hVEGF165 was implanted into the drilled tunnel of necrotic femoral head. In Group B, only DPB was implanted. In Group C, only tunnel was drilled without DPB or plasmid implanted. Femoral head specimens were obtained at postoperative 1, 2, 4, 8, 16 weeks. The expression of VEGF165 and collagen I was detected by immunohistochemistry. Bone formation was detected generally by X-ray. Angiogenesis and the repair of the femoral head were observed histologically.</p><p><b>RESULTS</b>The expression of VEGF 165 could be detected 2 weeks after implantation in Group A, but it was not observed in other groups. The result of collagen I expression had a significantly difference 2, 4 and 8 weeks after operation in Group A from those in other groups (P < 0.01). X-ray results indicated that there was more bone formation in Group A than in other groups. The regenerated capillary vessels staining result of necrotic femoral head in Group A was significantly different from those in other groups at postoperative 2 and 4 weeks (P < 0.01).</p><p><b>CONCLUSIONS</b>Transfection of hVEGF165 gene enhances local angiogenesis and DPB-VEGF compound improves the repair of necrotic femoral head. Deproteinized bone grafting with VEGF gene transfer provides a potential method for the treatment of osteonecrosis.</p>

Evaluation of early groin pain after total hip arthroplasty / 中华创伤杂志

Objective To discuss causes and corresponding prevention for groin pain occurred early after total hip arthroplasty(THA).Methods A retrospective study was done on 189 cases(193 hips)treated with THA including unilateral procedures in 185 hips and bilateral procedures in eight hips to analyze common causes for early groin pain.Results Groin pain was found in 9.3% hips(18/ 193)during hospital stay,including 1.6%(3 cases)with deep infection,1.6%(3 cases)with incision infection,1%(2 cases)with posterior dislocation,4.1%(8 cases)with leg lengthening and 1%(2 cases)with hematoma.Conclusions Despite of the numerous diagnostic alternatives available to the orthopedic surgeon,detailed history,careful physical examination,necessary laboratory and imaging stud- ies can contribute to a correct determination of causes for groin pain.Meanwhile,appropriate indication, accurate preoperative radiographic measurement,intraoperative standardized surgical procedures and per- fect rehabilitation are necessary to avoid complications.

Treatment of thoracolumbar burst fractures with bioactive artificial vertebrae of nano-hydroxyapatite and polymide 66 / 中华创伤杂志

Objective To investigate the efficacy of the bioactive artificial vertebrae of a nano- hydroapatite crystals and polyamide 66 composite(n-HA/PA66)to restore the height and architecture of thoracolumbar burst fracture.Methods From December 2003 to February 2006,38 patients(29 males and 9 females)with a mean age of 35.6 years(17-63 years)were treated surgically through anterior ap- proach for decompression and implanted with the bioactive artificial vertebrae of n-HA/PA66 composite to reconstruct the structure of the thoracolumbar burst fractured vertebra.Results All the patients were successfuly followed-up for an average of 8 months,ranging from 6 to 21 months.The bioaetive artificial vertebrac of n-HA/PA66 composite were fused with the receptor bone 3-4 months after operation.The neu- rological function of the patients was restored partially or completely.The thoracolumbar spine was stable during physical examination and the height of thoraeolumbar burst fractured vertebrae that had been restored did not changa during the follow-up.Conclusions Our results show the bioaetive artificial vertebrae of n-HA/PA66 can restore the height and structure of thoracolumbar burst fractured vertebrae and reconstruct the structure of the tboraeolumbar vertebrae effectively,indicating that the bioaetive artificial vertebrae of n- HA/PA66 can be used extensively in clinical spinal surgery.