Distribution and drug resistance of pathogens causing periprosthetic infections after hip and knee arthroplasty / 中国骨伤

OBJECTIVE@#To study the distribution and drug resistance of pathogens causing periprosthetic infections after hip and knee arthroplasty, and to formulate prevention and treatment strategies for drug-resistant bacteria.@*METHODS@#The data of 146 cases of periprosthetic infection after primary hip and knee arthroplasty from 2010 to 2015 were collected, including 111 cases of periprosthetic infection after hip arthroplasty and 35 cases of periprosthetic infection after knee arthroplasty. The culture positive rate, pathogenic bacteria composition and drug resistance rate were counted over the years, and the change trend of pathogen distribution and drug resistance was analyzed.@*RESULTS@#One hundredand eight strains of pathogenic bacteria were detected in 146 cases, and the positive rate of culture was 73.97%. Gram positive bacteria accounted for 55.48%, Staphylococcus epidermidis and Staphylococcus aureus accounted for 25.34% and 15.07% respectively. Gram negative bacteria accounted for 13.01%, including Enterobacter cloacae, Pseudomonas aeruginosa and Escherichia coli. There were 4 cases of Mycobacterium tuberculosis infection and mixed infection. The results of culture over the years showed that the constituent ratio of Gram positive bacteria had an increasing trend, fluctuating from 39.13% to 76.47%. The results of drug sensitivity showed that the pathogens were highly resistant to β-lactams, quinolones, clindamycin and gentamicin, and the drug resistance rate was increasing, but it was still sensitive to rifampicin, nitrofurantoin, tigecycline, linezolid and vancomycin.@*CONCLUSION@#Gram positive bacteria are the main pathogens of periprosthetic infection, and the proportion is increasing gradually.The pathogens have high resistance to many kinds of antibiotics, and the resistance rate is still increasing. To strengthen the monitoring of the distribution and drug resistance of pathogenic bacteria is helpful to grasp its change trend and formulate targeted prevention and control strategies.

Incidence and anatomic distribution of venous thromboembolism following primary total hip and knee arthroplasty: a prospective observational study / 中国骨伤

<p><b>OBJECTIVE</b>To analyze the incidence and anatomic distribution of venous thrombosis after total hip and knee arthroplasty by using the data of the patients with primary total hip and knee replacement.</p><p><b>METHODS</b>From December 2013 to December 2014, total hip and knee arthroplasty were performed in 1 686 patients, of which 928 were THA and 758 were TKA. Before and after discharge, all patients were routinely performed double lower limb vein color Doppler ultrasound, the conventional use of anti fibrinolytic drugs, postoperative anticoagulation for 14 d. The types and distribution of thrombosis after operation were statistical analysis.</p><p><b>RESULTS</b>Among 928 cases of primary total hip arthroplasty, there were 30 cases of thrombosis, 27 cases of isolated muscle vein thrombosis, followed by the involvement of the anterior or posterior tibial vein thrombosis, no central thrombosis. Among 758 cases of primary total knee arthroplasty, there were 87 cases of thrombosis, 81 cases peripheral thrombosis, 4 cases of thrombus of center type, the remaining 2 cases for mixed thrombus;74 patients with thrombosis involving a single vein, 65 cases involved muscle vein, 4 cases of femoral vein, 3 cases of posterior tibial vein, 2 cases of superficial vein; 13 cases of thrombosis involving multiple veins, involving muscle vein, posterior tibial veins, the peroneal veins and popliteal vein in 2 or 3 branches. The comparison results showed that the incidence of thrombosis after total knee arthroplasty was higher, the difference was statistically significant (<0.001), and more prone to central thrombosis and multiple venous involvement.</p><p><b>CONCLUSIONS</b>The incidence of thrombosis in patients with primary hip and knee replacement is low, and the incidence and anatomic distribution of the patients with primary hip and knee replacement are different.</p>

Meta-analysis comparing total hip arthroplasty with hemiarthroplasty in the treatment of displaced femoral neck fractures in patients over 70 years old / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>Total hip arthroplasty (THA) and hemiarthroplasty (HA) are effective methods currently used to treat femoral neck fracture in elderly patients, but the two options remain controversial in patients over 70 years old. The main purpose of our study was to determine whether THA or HA is a superior treatment of femoral fractures involving a displaced neck in patients who are over 70 years of age.</p><p><b>METHODS</b>A computer-based online search of Medline (1970-2011), PubMed (1977-2011), and the Cochrane Central Register of Controlled Trials (2002-2011) was conducted. Six relevant randomized controlled trials with a total of 739 patients were included for the final analysis. The analysis was performed with software RevMan 5.0.</p><p><b>RESULTS</b>We found that compared with THA, HA needed shorter average time and lost less blood. While over the long-term follow-up, THA patients exhibited significantly less pain and better function and were less likely to require a revision hip surgery. Postoperative infection was equally common among HA and THA patients.</p><p><b>CONCLUSIONS</b>The significant differences in outcomes suggest that THA is a valuable treatment option for active elderly hip fracture individuals. However, patients who are older, impaired or institutionalized benefit from HA.</p>

Midterm to long-term follow-up study after hybrid total hip arthroplasty / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate clinical and radiographic results and influencing factors of hybrid total hip arthroplasty (THA).</p><p><b>METHODS</b>Totally 126 patients (135 hips) from January 1999 to December 2001 accepted hybrid THA were followed up. Components migration, periprosthetic bone changes, the polyethylene wear rate were measured radiologically. Kaplan-Meier analysis was performed to evaluate the survival of the acetabular and femoral components. End point was obvious radiological loosening or revision either or both of the acetabular and femoral components for aseptic loosening, infection or osteolysis debridement surgery.</p><p><b>RESULTS</b>A total of 79 cases (85 hips) had been given follow-up. Using revision as the end point, the survival rate of acetabular was 95.2%, cemented femoral components was 98.8%. Using loosening as the end point for failure, the survival rate of acetabular was 97.6%, cemented femoral components was 100%.</p><p><b>CONCLUSIONS</b>The hybrid total hip prosthesis long-term survival rate was satisfactory, especially in the femoral side. As a result of third-cement technology, the long-term survival rate of the femoral components was close to the modern cementless prosthesis.</p>

Treatment of developmental dysplasia of hip by modified Sutherland pelvic osteotomy / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical results of modified Sutherland pelvic osteotomy for developmental dysplasia of hip (DDH).</p><p><b>METHODS</b>Sutherland pelvic osteotomy were performed in 10 patients (11 hips) with DDH. Among them, there were 3 male (3 hips) and 7 female (8 hips) patients, aged (32 ± 8) years. During operation, arthroscopes were performed additionally to remove the existing hyperplasia tissue in the fossae ovalis and trimming acetabulum and glenoid labrum, thus to insure the better match between the femoral head and the realigned acetabulum. The change of imaging indexes were acquired by comparing the preoperative X-ray with the postoperative X-ray. The change of hip function and life quality were acknowledged according to contrast and analysis Harris hip score and Short Form 12-items Health Survey (SF-12) before and after osteotomy.</p><p><b>RESULTS</b>All patients were followed up for a mean of (5.2 ± 2.3) years, the osteotomy were all union in 3 months. The acetabular head index was 71 ± 8 before operation, and 86 ± 4 after operation. The pre- and post-operative centre edge angle were (7 ± 9)° and (33 ± 9)°, sharp angle were (48 ± 4)° and (37 ± 5)°, acetabular index angle were (24 ± 8)° and (11 ± 5)° respectively. The average Harris score improved from 42 ± 13 preoperatively to 90 ± 5 postoperatively, with 100% excellent and good results. Every domains of SF-12 was improved in the different extents postoperatively, the improvement of physical component summary was more conspicuous than mental component summary. The imaging indexes, Harris and SF-12 were all improved with significant difference (all P < 0.05).</p><p><b>CONCLUSIONS</b>The modified Sutherland pelvic osteotomy is effective. It could increase the load bearing capacity of hip, and improve the quality of life.</p>

Impaction morselized allografting combined with cementless long stem for femoral defects in femoral component revision / 中华外科杂志

<p><b>OBJECTIVE</b>To retrospectively analyze the clinical and radiological results of the impaction morselized allografting combined with cementless long stem for femoral component revision in patients with significant bone loss.</p><p><b>METHODS</b>From July 2003 to June 2009, 27 patients (27 hips) underwent revision hip arthroplasty in femurs with bone defect using impaction allografting and cementless components. There were 15 male and 12 female with mean age of 67 years. According to the Paprosky classification system, the bone defects in femur were classified into type II in 3 cases, type III in 21 cases and type IV 3 cases. The patients were followed up postoperatively to observe the clinical and radiological results, and if there had the stem subsidence, periprosthetic fracture, infection and other complications.</p><p><b>RESULTS</b>Twenty-three patients were followed up. The mean follow-up time was 26 months. Harris score improved from 43 points pre-revision to 83 points at the final follow-up. No femoral stem loosening and failure occurred. There were 4 stem with a mean 3.3 mm subsidence. One case had an acute infection after revision and treated successfully by debridement and drainage, antibiotics. No stem need further revision. Radiographic analysis showed all the revised stem was stable, and graft incorporation was seen in at least 1 zone in 100% of the femurs.</p><p><b>CONCLUSION</b>The results of this study demonstrates that femoral support and vigorous impaction grafting combined with cementless long stem results in an good intermediated-term clinical effects.</p>

Cortical windowing of the femoral diaphysis for cement/plug removal in hip revision surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the results of cortical windowing of the femoral diaphysis for well-fixed cement/plug removal during hip revision surgery.</p><p><b>METHODS</b>From May 2005 to June 2009, 14 patients (14 hips) were undergone revision total hip arthroplasty (THA), window was cut into the cortex of the femur, and the well-fixed cement/plug distal to the window was removed under the direct vision. After reimplanted the cementless revision stem, the cortical lids were replanted and fixed with 2 to 3 cerclage wires. Six patients who had suffered from osteoporosis were undergone morselized bone graft to the osteotomy site. Postoperatively, the patients were maintained at partial weight-bearing (touchdown) for 6 weeks and then advanced as they were able.</p><p><b>RESULTS</b>The length of the cortical windows varied from 2.5 to 6.0 cm (mean, 3.4 cm), the width ranged from 0.8 to 1.4 cm (mean, 1.2 cm). In one patient the window was enlarged during the procedure to facilitate the cement/plug removal. The mean radiologically healing time for the windows was 19 weeks. There was no intraoperative femoral perforation during cement/plug removal. One femoral fracture during the revision stem was implanted. No postoperative periprosthetic fracture and other complications such as infection, implant subsidence occurred during the fellow-up. There was no femoral thigh pain or implant loosening with femoral window.</p><p><b>CONCLUSION</b>The cortical windowing technique is very helpful to facilitate the well-fixed cement/plug distal to the prosthesis tip removal and the windows heal rapidly and decrease the femoral complications associated with revision THA.</p>

Effect of T-2 toxin on growth and development of rat knee epiphyseal plate and metaphyseal bone in normal and low nutritional status / 中国地方病学杂志

Objective To observe the effect of T-2 toxin on growth and development of rat epiphyseal plate of left knee and metaphyseal bone of femur and tibia in normal and low nutritional status, to find out possible pathogenic factors of Kashin-Beck disease and provide experimental basis for early intervention. Methods Ninety 3-week-old Wistar rats, weighing 60 - 70 g, were randomly divided into three groups: control group(general feed), T-2 toxin + general feed group, T-2 toxin + low nutrition feed group, thirty rats in each group with equally sex ratio. T-2 toxin (1.0 mg/kg) was administered orally 5 times a week via a gavage needle for 4 weeks. The change of hair, activity and body weight was observed. After 1, 2, 4 weeks, the epiphyseal plate of left knee and metaphyseal bone of femur and tibia (including distal femur and proximal tibia) were collected. Specimens were processed with HE and Masson staining. The morphology of chondrocytes and matrix collagen content in epiphyseal plate was observed. Trabecular bone volume fraction in tibial metaphyseal bone was analyzed by Image-Pro Plus 6.0 software. Results In the control group, rats were in good movement and hair with light, but in T-2 toxin + general feed group and T-2 toxin + low nutrition feed group, rats were found with reduced activities and hair with dark color. Body weights(g) of the control group, the T-2 toxin + general feed group and the T-2 toxin + low nutrition feed group were 81.0 ± 6.2, 79.0 ±5.1, 77.0 ± 7.5, respectively, by the end of first week; 101.8 ± 6.7, 97.0 ± 6.8, 93.0 ± 5.3, respectively, by the end of second week; 151.1 ± 15.7, 126.5 ± 11.9, 106.5 ± 11.5, respectively, by the end of fourth week. There was significant difference in groups by second week and the fourth week (F = 9.72, 41.65, all P ＜ 0.05 ). There was significant difference among multi-groups by the fourth week(all P ＜ 0.01 ). Under light microscope, at the second weeks, coagulative necrosis of chondrocytes was found in hypertrophic zone in the two groups with T-2 toxin; at the fourth weeks, cell necrosis increased. Masson staining showed collagen staining in the two groups with T-2 toxin significantly turned to clear pale coloration, indicating that the collagen matrix was significantly reduced. Image analysis showed there was significant difference in groups at the second and fourth week(F= 9.72, 41.65, all P＜ 0.05)in tibial metaphyseal trabecular bone volume fraction. There was significant difference between T-2 toxin + low nutrition feed group[(0.55 ± 0.12)％, (0.21 ± 0.0)％] and control group[(0.67 ± 0.09)％, (0.51 ± 0.14)％] by the second and fourth week(all P ＜ 0.01 ). Conclusions Under normal nutritional status, T-2 toxin can induce hypertrophic epiphyseal cartilage necrosis, collagen content decreased in epiphyseal plate, metaphyseal trabecular bone formation disorders; in the low nutritional status, T-2 toxin can lead to rat epiphyseal necrosis and significant metaphyseal bone disorder, but whether the performance is related to Kaschin-Beck disease needs to be studied further.

Effects of perioperative administration of celecoxib on pain management and recovery of function after total knee replacement / 中华外科杂志

<p><b>OBJECTIVE</b>To assess the effect of perioperative administration of a selective cyclooxygenase 2 inhibitor (celecoxib) on pain management and recovery of function after total knee arthroplasty (TKA).</p><p><b>METHODS</b>Randomized, controlled trial conducted from January 2005 through February 2006, 60 patients underwent TKA for osteoarthritis or rheumatoid arthritis were randomly divided into group of perioperative, administration of celecoxib (Study group, n = 30) and postoperative administration of celecoxib (Control group, n = 30). Patients in Study group were given oral celecoxib 3 d before TKA, 200 mg twice daily, and extended to 5 d postoperatively; patients in Control group were given oral celecoxib 2 h after TKA, 200 mg twice daily, and extended to 5 d postoperatively. All operations were finished by the same surgeon group.</p><p><b>RESULTS</b>The postoperative patient-controlled analgesia (PCA) consumption was significantly less in Study group than in Control group [(43 +/- 12) ml vs. (53 +/- 12) ml, P < 0.05]. The pain scores of postoperative 4, 8, 12 h, 1, 2 d in Study group were 6.1 +/- 1.2, 5.0 +/- 1.3, 4.3 +/- 1.1, 3.4 +/- 1.2, significantly less than in Control group (P < 0.05); There were no intergroup significant differences in the pain scores of postoperative 3, 4, 5 d (P > 0.05). There were no intergroup significant differences in respect to the side-effect occurrence, operation time and postoperative drainage, postoperative analgesic consumption (P > 0.05). The time to achieve 90 degrees knee flexion was significantly shorter in Study group than in Control group [(6.2 +/- 1.7) d vs. (8.6 +/- 1.8) d, P < 0.05].</p><p><b>CONCLUSIONS</b>Perioperative administration of the selective Celecoxib holds the effect of preemptive analgesia. Compared with postoperative administration, perioperative administration of celecoxib can alleviate the early postoperative pain score, reduce the consumption of postoperative analgesic, accelerate the recovery of joint motion and thus increase the patient satisfaction.</p>

Extended trochanteric osteotomy for removal of solidly-fixed femoral implants in total hip revision / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the clinical and radiographic results of the extended trochanteric osteotomy in revision total hip arthroplasty procedure.</p><p><b>METHODS</b>The data of 27 patients (27 hips) of the clinical and radiographic results were reviewed between January 1998 and June 2005. There were 16 men and 11 women, and the mean age at the time of revision surgery was 63 years (range 42 to 78 years). Indications for use of the trochanteric osteotomy were removal of well-fixed femoral implants. Clinical evaluation included Harris and WOMAC scores. The radiological evaluation included stem subsidence, trochanteric fragment fractures and stem position change.</p><p><b>RESULTS</b>Nineteen patients (19 hips) were followed up for an average of 5.3 years. All osteotomy sites healed by 16 months,with an average time to union of 16 weeks. No intraoperative fracture at the osteotomy site occurred. There was only one dislocation postoperatively. Three femoral components were subsidence at a mean of 3.4 mm (range 3-7 mm) in the first 6 weeks postoperatively; It united within 6 months without further migration.</p><p><b>CONCLUSIONS</b>The extended trochanteric osteotomy facilitates the removal of well-fixed femoral implants, allows reliable reattachment of the trochanteric fragment and results an excellent rate of healing and implant stability in revision total hip arthroplasty during mid-term follow-up. Long-term follow-up is needed.</p>

Immunological study on the transplantation of an improved deproteinized heterogeneous bone scaffold material in tissue engineering / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To observe the immune response after the transplantation of a deproteinized heterogeneous bone scaffold and provides the theoretic reference for clinical practice.</p><p><b>METHODS</b>The fresh pig bone and deproteinized bone were transplanted respectively to establish BABL/C thigh muscle pouches model of male mice and take the samples for detection at 1, 2, 4, 6 weeks after operation. Lymphocyte stimulation index, subset analysis, serum specific antibody IgG, cytokine detection and topographic histologic reaction after implantation were investigated.</p><p><b>RESULTS</b>After the transplantation of deproteinized bone, lymphocyte stimulation index, CD(4)(+) and CD(8)(+) T-lymphocyte subsets, serum specific antibody IgG and cytokines in deproteinized bone group were significantly lower than those in fresh pig bone group at each time point (P<0.05). The histological examination found that in fresh bone group at each time point, a large quantity of inflammatory cells infiltrated in the surrounding of bone graft, and they were mainly lymphocytes, including macrophages and monocytes. In deproteinized bone group, there were few inflammatory cells infiltration around bone graft one week after operation. The lymphocytes were decreased as time went by. At 6 weeks, fibroblasts and fibrous tissue grew into the graft, and osteoclasts and osteoprogenitor cells appeared on the verge.</p><p><b>CONCLUSIONS</b>The established heterogeneous deproteinized bone has low immunogenicity and is a potentially ideal scaffold material for bone tissue engineering.</p>

Analysis of patients with bone injury in Wenchuan earthquake / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the patients with bone injury in Wenchuan earthquake.</p><p><b>METHODS</b>From May 12th to June 15th 2008 the data of 1410 patients with bone injury in Wenchuan earthquake were analyzed to evaluate clinical intervention and remedy-managing experience.</p><p><b>RESULTS</b>The 1410 patients average age was from 4 to 103 years old. And 744 cases (52.7%) suffered from blunt injuries, 379 cases (26.9%) from buried injuries, 287 cases (20.4%) from falling injuries; And 1317 cases were with fracture, 93 with limbs soft tissue injuries; 261 patients combined with other parts of injuries including 45 cases with paralysis; 66 cases were with crush syndrome, 25 with gas gangrene, 76 with acute kidney failure, 26 with multiple organ failure. And 912 operations were performed including 402 fracture fixation, 224 debridement, 152 debridement and suture, 85 amputation, 29 implant skin, 8 fixation of joint dislocation, 5 surgical flaps transplantation, 4 nerve and tendon suture, 2 arthroscopes, 1 joint replacement. Among the 66 crush syndrome patients, 49 accepted continuous renal replacement therapy, in which 9 cases were bleeding from named arteries and 20 blood vessels were getting embolism. Among the 1410 cases, 1 died from multiple organ failure.</p><p><b>CONCLUSIONS</b>Among the patients with bone injury in Wenchuan earthquake, the elderly patients are more than the youth; The injuries are always combined with other complications; Opened injuries are polluted severely; It is difficult to deal with the crush syndrome; Paraplegia cases are less, but the amputees are more.</p>

Cellular compatibility of improved scaffold material with deproteinized heterogeneous bone / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study cellular compatibility of improved scaffold material with deproteinized heterogeneous bone and provide experimental basis on choosing the scaffold material in bone tissue engineering.</p><p><b>METHODS</b>Bone marrow stromal cells (BMSC) were co-cultured with heterogeneous deproteinized bone in vitro. The contrast phase microscope, scanning electron microscope, MTT assay, flow cytometry were performed and the BGP content and ALP activities were detected in order to observe the cell growth, adhesion in the material, cell cycle and cell viability.</p><p><b>RESULTS</b>The scaffold material of deproteinized heterogeneous bone had no inhibitory effect on cellular proliferation, differentiation and secretion function of BMSCs.</p><p><b>CONCLUSIONS</b>The established heterogeneous deproteinized bone has good biocompatibility with BMSCs and is a potentially ideal scaffold material for bone tissue engineering.</p>

One family investigation and risk factors analysis of developmental dysplasia of the hip / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the clinical manifestations and risk factors of the patients from developmental dysplasia of the hip(DDH) family.</p><p><b>METHODS</b>Detailed epidemiology investigation, physical examination, functional movement assessment, lab test and X-ray examination were applied to the whole members of a DDH family.</p><p><b>RESULTS</b>In the family with 9 generations and 218 persons, the incidence of DDH was 31.03% in 145 survivors. Patients mainly manifested bilateral knee and hip joint pain, flexion contracture of hip, limitation in internal and external rotation of hip; a few had arthritic functional disorder, deformation, and limp. The radiography illustrated shallow acetabulum with increased inclination, which encompassed the femoral head badly. Deformation of the femoral head, narrow joint space and osteophyte were also found by X-ray examination. The main risk factors of DDH were genetic factors, gender, birth season etc. The son or daughter with one or two DDH parents had a higher risk for developing DDH than those with no DDH parents. Furthermore, first-degree relatives of the DDH patients also had a greater chance to develop DDH than second-degree relatives and third-degree relatives. The incidence among females was higher than males, and the family member who was given birth in winter had a highest risk for developing DDH. However, there was no difference between incidence of DDH in children and youths and in adults; the incidence of DDH in the immigrants with no blood relationship also did not differ from the incidence of DDH in the family member.</p><p><b>CONCLUSION</b>The genetic factors play an important role in the development of DDH, so do the environmental factors.</p>

Reconstruction of periprosthetic fractures of hip with cortical bone plates allografts / 中华外科杂志

<p><b>OBJECTIVE</b>To observe clinical results for reconstruction of periprosthetic fractures of hip with cortical bone plates allografts by deep-freezing and ethylene oxide treatment.</p><p><b>METHODS</b>Seven patients with periprosthetic fractures of hip underwent cortical bone plates allografts by deep-freezing at -70 degrees C after being treatment of 48 degrees C ethylene oxide. And evaluate clinical outcome by examining T lymphocytes, Harris scores, X-rays photograph, and bone scintigraphy.</p><p><b>RESULTS</b>There were not activity of immune rejection and infection in all patients. Harris scores of patients increased 21, 32, 40, 40 scores at 3, 6, 12, 24 months after surgery. T-lymphocytes, antibody and immunocomplex in blood was normal postoperation. X-ray film indicated that fracture was healed at 3 months and there was partially bone conjunction between allograft strut and host bone. There was incorporation of 85% allograft strut to host bone, and 15% allograft strut was partially absorbed at 12 months after surgery. The size of femur of host was added 3 mm to 5 mm, averaged 4.3 mm at 12 months postoperation. Density of 80% allograft plates was as same as host bone after remodeling and the absorbtion of 10% allograft plates stopped at 24 months after surgery. There was thick of nuclein in the area of allograft cortical bone plates by bone scintigraphy examination at 3 months postoperation, and the thick of nuclein was stronger at 6, and 12 months after surgery.</p><p><b>CONCLUSION</b>Allograft cortical bone plates by deep frozen at -70 degrees C after being treatment of 48 degrees C ethylene oxide is suitable for mechanical fixation and biological bone transplantation, and it can increase bone reservation, augment strength of femur once the allograft strut incorporates to host bone, and avoid removing metal implant in second operation when being applied into reconstruction femoral fracture in joint replacement.</p>

An experimental study of cell apoptosis and correlative gene expression after tractive spinal cord injury in rats / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the cell apoptosis after tractive spinal cord injury in rats, determine expression of apoptosis correlative genes, and study the molecular mechanism of cell apoptosis.</p><p><b>METHODS</b>The T(13)-L(2) spinal cord of rats was injured by traction after the amplitude of P1-N1 wave decreased to 70% in postoperation than in preoperation through cortical somatosensory evoked potential (CSEP) monitor. Then rats were killed in 30 min, 6 h, 1, 4, 7, 14 and 21 d respectively after operation (n = 4). Cell apoptosis was examined by the flow cytometer and terminal deoxynucleotidyl transferase-mediated DUTP-biotin nick end labeling (TUNEL) reaction, the expression of p53, bax and bc1-2 genes was tested with immunohistochemistry.</p><p><b>RESULTS</b>The flow cytometer test and TUNEL method showed that the apoptosis cell ratio raised in 6 h and reached at peak in 7 d after injury, and then declined till 21 d, they showed significant difference (P < 0.05, 0.01). TUNEL method showed that injured group had a large number of apoptosis glial cells in white matter. Immunohistochemical staining showed that the positive expression of p53, bax and bc1-2 protein raised at 6 h, expression of p53 protein reached at peak in 4 d, bax and bc1-2 protein reached at peak in 7 d after injury. Compared with control group and laminectomy group, the injured group showed significant difference (P < 0.05, 0.01).</p><p><b>CONCLUSION</b>There is cell apoptosis phenomenon after tractive spinal cord injury in rats. Morphology indicates that apoptosis includes neurons and glialcytes, which is an important form of cell death and pathological changes in secondary lesion period after tractive spinal cord. There exist high expression of apoptosis correlative gene p53 and bax after spinal cord injury, they may play an important role in reduction of cells to apoptosis.</p>

Observation and establishment of an animal model of tractive spinal cord injury in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To establish an animal model of tractive spinal cord injury in rats in order to investigate its pathophysiological changes and clinical significance.</p><p><b>METHODS</b>T(12)-L(3) spines were tracted longitudinally with a special spinal retractor that was put on the proccessus transverses of T(12)-L(3) vertebrae of the rat after exposing T(13)-L(2) spinal cord via dual laminectomy. At the same tine, the spinal cord function was monitored by cortical somatosensory evoked potential (CSEP). Rats were randomly divided into four groups according to the amplitude of CSEP P(1)-N(1) wave, the amount of the decreasing P(1)-N(1) wave was 30% (the 30% group), 50% (the 50% group) and 70% (the 70% group), respectively. After traction, the changes of the neural behavioral function in rats were observed and the morphological structure of the spinal cord was analyzed quantitatively with image analysis system of computer.</p><p><b>RESULTS</b>With traction of spine, compared with the control group, the 30% group had no marked difference in combined behavioral score (CBS), neuron count, section area of neuron and Nissl body density, but the 50% and 70% groups had marked difference (P<0.01). Light microscope showed that the neuron volume was slightly small and the Nissl body was reduced lightly in the 30% group; the neuron space was enlarged and the neuron was degenerative, reductive, and dissolved, and the spinal cord structure was destroyed in the 50% and 70% groups.</p><p><b>CONCLUSIONS</b>The animal model of tractive spinal cord injury in rats is a reproducible, graded and clinic mimic. The model in this article provides a valuable assistance in further understanding etiopathology and screening effective measures of therapy and prophylaxis of the injury.</p>

Treatment of Vancouver type-B periprosthetic femoral fractures after total hip arthroplasty / 中华创伤杂志

Objective To study treatment of Vancouver type-B periprosthetie femoral fractures after total hip arthroplasty.Methods There were 10 cases with Vancouver type-B periprosthetic femo- ral fractures after total hip arthroplasty being treatment,including three cases with type-B1 undergone open reduction and allografi strut to fix the fracture,two with type-B2 undergone open reduction and revi- sion with a long stem and five with type-B3 undergone open reduction,revision with a long stem and al- lograft strut to restore bone.The mean duration of follow-up was 27 months(8-36 months).The Harris Hip Score and radiographs were used to evaluate the outcome.Failure of the procedure.was defined as the need for revision surgery because nonunion of fracture,implant loosening,and infection.Results All cases obtained successful fracture healing,with no stem loosening or infection.Of all,nine cases were a- ble to walk by themselves but one needed aid in walking.The Harris Hip Score was 83 at the time of the final follow-up.Osseous union of the allograft to the host femur occurred in eight hips and mild graft re- sorption in two.The cotex thickness of host femur was increased more than 3-5 mm.Conclusions Stem stability and bone quality are important factors determining the outcome of treatment for periprosthet- ic femoral fracture after hip arthroplasty.Good outcome can be achieved by adopting different treatments according to sub-classification of Vancouver type-B fractures.The allograft strut for the treatment of a Vancouver type-B periprosthetic femoral fracture can not only provide fixation,but also make fracture heal fast and augment bone mass and strength.