Objective To summarize the bacterial types and drug resistance of children with bone and joint purulent infection in the Affiliated Hospital of Zunyi Medical College in recent 9 years,so as to provide reference for rational use of antibiotics in clinics.Methods A retrospective study was performed on the clinical data of 102 children with hematogenous bone and joint purulent infection in the Affiliated Hospital of Zunyi Medical College from January 2008 to October 2016,in which there were 57 boys and 45 girls with a mean age 5.5 years old(from 10 days to 14 years old),among which 38 cases were acute osteomyelitis,30 cases were pyogenic arthritis,27 cases were chronic osteomyelitis,and 7 cases were arthritis with hematogenous osteomyelitis.The results of blood culture,pus culture and antibiotic sensitivity test results were analyzed and summarized.Results The results of blood culture or pus culture in 102 cases were all infected by single bacteria,including 89 cases of staphylococcus aureus(SA),accounting for 87.30％,3 cases (2.94％) of micrococcus scarlatinae,2 cases (1.96％) of klebsiella pneumoniae,2 cases (1.96％) of staphylococcus haemolyticus,and 1 case (0.98％) of methicillin-resistant staphylococcus epidermidis,streptococcus pneumoniae,streptococcus mitis,enterococcus hirae,enterobacter cloacae and pseudomonas aeruginosa,respectively.The resistance rate of SA to penicillin was 92.1％,but to Lincomycin,Erythromycin,Cefoxitin and Tetracycline it was more than 50.0％,and to Sulfamethoxazole,Gentamicin and Rifampicin it was quite low,and the resistant strains to Linezolid,Quinupristin/Dafoe Putin,Mo Xisha star,Tigecycline,Vancomycin,Levofloxacin,Nitrofurazone were no found.There were not multi drug resistant strains to be found except in the 45 cases of methicillin-resistant staphylococcus aureus(MRSA) and 1 case of methicillin-resistant staphylococcus epidermidis.Conclusion SA is the main pathogenic bacteria of bone and joint purulent infection in children in the local area.The resistant rate of penicillin and the detection rate of MRSA are high in the hematogenous osteoarticular infections caused by SA,but no vancomycin resistant cases were found.

Objective To investigate the morphological characteristics of elbow dislocation associated with elbow fracture in children,to propose its injury mechanism,and to present its treatment and outcomes.Methods From January 2010 to September 2016 in Department of Pediatric Orthopedics,the Affiliated Hospital of Zunyi Medical College,the clinical data of elbow dislocation associated with elbow fracture were retrospectively analyzed in 12 children,in which there were 9 boys and 3 girls with a mean age of 7.6 (3.6-12.O) years,and the injury time was 6 h-32 days,with an average of 3.5 days.According to the direction of dislocation,posterior dislocation in 6 cases,posterolateral dislocation in 4 cases,and anterior dislocation in 2 cases.Twelve cases were caused by high energy injury,accompanied with violent rotary injury of forearm,including traffic accident injury in 5 cases,high fall injury in 4 cases,motor belt injury in 2 cases,and washing machine injury in 1 case.All these cases were treated with surgery,the dislocated elbow joint were reset,the fracture fragments were fixed with Kirschner wire or wire tension band,and the lateral collateral ligament were repaired.Results All cases were followed up for 6-23 months,with an average 13.5 months.The stability of elbow joint and the fracture healing were very good,and no elbow redislocation at the last follow-up.The function of elbow joint recovered satisfactorily,the extension-flexion motion ranged from 90°-145°,with an average of 125°,and the pronation-supination motion ranged from 85°-155°,with an average of 130°.According to the Mayo functional index,the results were excellent in 7 cases and good in 4 cases,and the excellent and good ratio was 91.7％ (11/12 cases).Conclusions The elbow dislocation of children is caused by high energy injuries and the violent rotational injury of the forearm,easily combined with different types of elbow fractures and severe injury of collateral ligament.Surgical treatment should be actively performed to restore the normal anatomy,reconstruct the stability and restore the function of the elbow joint.

Objective To investigate the drug resistance and its changes of Staphylococcus aureus (SA) in children with bone and joint infection caused by hematogenous dissemination in Zunyi area.Methods A retrospective study was performed on the clinical data of 95 cases with bone and joint infections caused by SA from January 2008 to December 2016 in the Affiliated Hospital of Zunyi Medical College,in which there were 53 boys and 42 girls with a mean age of 5.6 years (ranging from 10 days to 14 years),including 39 cases of acute osteomyelitis,31 cases of acute suppurative arthritis,19 cases of chronic osteomyelitis,and 6 cases of acute osteomyelitis and arthritis.According to the results of drug sensitivity,the drug resistance of SA was analyzed,and the detection rates of Methicillin resistant Staphylococcus aureus (MRSA) were compared in different genders and timeframes,and the drug resistance of SA to other antibiotics were also analyzed.Results The detection rate of MRSA was 50.53％ (48 cases) in 95 cases,the resistance rate to Penicillin was 92.63％ (88 cases),and to Lincomycin,Erythromycin,Tetracycline and Cefoxitin were 64.21％ (61 cases),57.90％ (55 cases),55.79％ (53 cases) and 53.68％ (51 cases) respectively,but to Sulfamethoxazole Co.,Gentamicin and Rifampicin it was relatively low[25.26％ (24 cases),11.58％ (11 cases),6.32％ (6 cases) respectively],while the resistance to Moxifloxacin,Linezolid,Tigecycline,Vancomycin and Nitrofurantoin was not found.The detection rate of MRSA in boys (52.83 ％,28/53 cases) was slightly higher than that of girls (47.62％,20/42 cases),but the difference was not statistically significant (x2 =0.255,P ＞0.05).The detection rates of MRSA in 2008-2010,2011-2013 and 2014-2016 were 27.78％ (5/18 cases),51.61％ (16/31 cases) and 58.70％ (27/46 cases) respectively,and it was obviously higher in 2014-2016 than in 2008-2010,and the difference was statistically significant (x2 =4.95,P ＜ 0.05).The drug resistance rate of SA to Lincomycin,Erythromycin and Cefoxitinis was obviously higher in 2014-2016 than in 2008-2010,and the differences were all statistically significant (all P ＜ 0.05).Conclusions The drug resistance of SA is high with the bone and joint infection caused by hematogenous dissemination in children,and the detection rate of MRSA and the drug resistance of SA to a variety of antimicrobial agents are gradually increasing.

Objective To compare and study the effect of two practice models on clinical practice teaching in pediatric orthopedic surgery.Methods A total of 60 5-year undergraduate interns were selected and assigned randomly separately into control group (n=30) and experimental group (disease-based internship group,n=30).The control group took bed-based internship model,that is,interns managed patients with fixed beds.The experimental group took disease-based internship model,that is,interns managed the same disease patients and rotated regularly.Both groups used the same teaching method,namely the PBL+ LBL teaching.At the end of the internship,SPSS 18.0 was used to analyze the data,the independent sample t test and Chi-square test were used to compare the results of the two groups.Results In the dimensions of theoretical knowledge,medical records written and consolidated results,the score of the experimental group were higher than the control group,and the differences were statistically significant (P＜0.05).The score of practical skill in two groups had no statistically significant difference (P＞0.05).The satisfaction survey showed that the experimental group had higher satisfaction than the control group,and the difference was statistically significant (P＜0.05).Conclusion The disease-based internship model is better than the bedbased internship model in clinical practice teaching in pediatric orthopedic surgery,and can improve the quality of clinical teaching practice.

Objective:To analyze the clinical characteristics of bone tumors in children, so as to improve the understanding and diagnosis of bone tumors in children.Methods:The clinical data of bone tumors in children hospitalized in the Affiliated Hospital of Zunyi Medical University from January 2009 to December 2018 were collected, with the age ≤ 14 years old.All children′s gender, age, tumor type, location, number of lesions and first symptoms were counted, and the clinical characteristics of bone tumors in children in this area were analyzed.Results:Totally 548 children with bone tumor were collected, with 344 males and 204 females, and the ratio of males to females was 1.69∶1.00, with 462 single cases and 86 multiple cases.Among the multiple cases (86 cases), 82 cases (95.35%) were benign bone tumors.The total number of cases increased with age.The age of different tumors has its own characteristics.Tibia was the most common tumor location (223 in total), followed by femur (177 in total) and humerus (82 in total). According to the classification of tumor nature, there were 478 cases (87.22%) of benign bone tumors, 43 cases (7.85%) of intermediate bone tumors and 27 cases (4.93%) of malignant bone tumors.The incidence of benign bone tumors was significantly higher than that of intermediate and malignant bone tumors, with statistically significant differences ( χ2=72.604, P<0.05). Among the benign bone tumors (478 cases), osteochondroma was the most common (265 cases), accounting for 55.44%; among the intermediate bone tumors (43 cases), aneurysmal bone cyst was the most common (20 cases), occupying 46.51%; among the malignant bone tumors(27 cases), osteosarcoma was the most common (16 cases), accounting for 59.26%.Among the initial symptoms, 268 cases were local masses, and 166 cases were pain, which were significantly higher than that of 79 without symptoms, with 28 lameness, 4 deformity and 3 dysfunction, and the differences were statistically significant( χ2=71.422, P<0.05). Conclusions:The majority of bone tumors patients in children were male, and the incidence increased with age.Benign and solitary are common, and the multiple cases were mainly benign.The most common locations are tibia and femur.The initial symptoms were mainly local mass and pain.Most importantly, the clinical characteristics of different tumors are slightly different.

Objective:To explore the relationship between the transforming growth factor-β (TGF-β) signaling pathway and steroid-induced osteonecrosis of the femoral head in young rabbits.Methods:Sixty 8-week-old rabbits weighing 1.5-2.0 kg were randomly divided into steroid injection group (48 cases) and control group (12 cases). Rabbits in the former group were injected with Prednisolone Acetate 7.5 mg/kg into bilateral gluteal muscles twice a week for 8 weeks, and those with successful modeling were included in the disease group; otherwise, they were included in the non-disease group.Rabbits in control group were similarly injected with the same volume of 9 g/L saline.Penicillin sodium 50 000 U/rabbit was injected once a week for preventing infection.After 8 weeks of injection, CT was performed in all the experimental animals.They were then sacrificed for collecting bilateral femoral heads.Expression levels of TGF-β1, TGF-β2, Smad2 and Smad3 in the femoral head were detected by enzyme linked immunosorbent assay (ELISA), and the mRNA level of Runx2 in the femoral head was detected by quantitative real-time PCR (qPCR), the expression differences of related factors in each group were compared.Results:In steroid injection group (48 cases), 6 rabbits were sacrificed, and 32 survived, involving 6/32 cases (18.75%) experimental animals with positive avascular necrosis (disease group), and 26 negative ones (non-disease group). ELISA data showed that expression levels of TGF-β1 in control group, non-disease group and disease group were (77.12±14.62) ng/L, (90.17±11.90) ng/L and (126.14±25.66) ng/L, respectively ( t=3.35, 4.24, all P<0.05). The expression levels of TGF-β2 in control group, non-disease group and disease group were (74.54±7.63) ng/L, (89.24±9.51) ng/L and (109.74±16.45) ng/L, respectively ( t=4.12, 5.65, all P<0.01). The expression levels of Smad2 in control group, non-disease group and disease group were (17.74±2.72) μg/L, (23.82±3.58) μg/L and (31.28±3.88) μg/L, respectively ( t= 4.54, 7.99, all P<0.01). The expression levels of Smad3 in control group, non-disease group and disease group were (1.76±0.52) μg/L, (2.39±0.45) μg/L and (3.53±0.47) μg/L, respectively ( t=5.60, 6.71, all P<0.01). qPCR data showed that the mRNA levels of Runx2 in control group, non-disease group and disease group were 1.02±0.17, 1.27±0.14, and 1.72±0.11, respectively ( t=7.60, 8.91, all P<0.01). Conclusions:TGF-β is up-regulated in the model of steroid-induced osteonecrosis of the femoral head in young rabbits, which stimulates the proliferation and differentiation of osteoblasts and osteoclasts, and triggers the process of bone remodeling.The TGF-β signaling pathway involved in the repair of necrotic bone.

Objective:To analyze the characteristics of aneurysmal bone cysts (ABC) and related factors of postoperative recurrence, so as to improve the clinical diagnosis and treatment level of ABC in children.Methods:The clinical data of children pathologically diagnosed as ABC after surgery in the Affiliated Hospital of Zunyi Medical University from January 2010 to December 2018 were retrospectively analyzed.Clinical characteristics of the patients, including age, gender, lesion sites, and main clinical manifestations (pain, swelling, local tenderness, joint dysfunction and pathological fracture) were analyzed and summarized.Before operation, imaging Enneking staging was carried out, cyst volume was estimated, and the distance from cysts to the epiphyseal plate was measured.During surgery, patients received lesion curettage, local cautery and bone grafting, and the pathological fractures were treated with auxiliary internal fixation.Results were determined by Neer imaging grading after surgery, and grades Ⅰ and Ⅱ were postoperative recurrence.Possible recurrence factors were analyzed statistically by Fisher′ s exact test. Results:A total of 29 cases meeting the criteria were included, including 19 males and 10 females.The age ranged from 3.6 to 14.0 years old, averaging 9.2 years old; 12 patients were smaller than 10 years old and 17 patients were older than 10 years old.The cysts of 9 cases were located in proximal femur (31.0%), 5 cases in proximal humerus (17.2%), and 4 cases in proximal fibula (13.8%); The other 11 cases (37.9%) occurred in the middle and distal end; 26 cases (89.7%) had local tenderness, 25 cases (86.2%) showed varying degrees of pain, 18 cases (62.1%) presented local swelling, 15 cases (51.7%) were accompanied by joint dysfunction, and 12 cases (41.4%) were combined with pathological fractures.According to Enneking staging results, 18 cases (62.1%) were at rest stage, 7 cases (24.1%) at active stage, and 4 cases (13.8%) at invasive stage.Cyst volume was estimated to be 3.3-172.0 cm 3, with a median of about 50.8 cm 3.The distance from cysts to the epiphyseal plate was 0-85.0 mm, with a median of 20.8 mm.All children were followed up for 2.2-10.1 years (averaging 3.8 years). There were 6 cases (20.7%) of grades Ⅰ and Ⅱ according to Neer grading standard, and they suffered from recurrence about 2.5-20.3 months after surgery (averaging 12.5 months). The recurrence rate was higher in patients with cyst volume >50.8 cm 3 (42.9%, 6/14 cases) as well as in patients at active stage and invasive stage (45.5%, 5/11 cases) ( P<0.05). There was no statistical difference between the recurrence rate of ABC in different gender, age, the distance from cysts to the epiphyseal plate and pathological fractures. Conclusions:ABC is prone to occur in the proximal metaphysis of the long bones of children′s extremities.Main manifestations are pain, swelling, local tenderness and joint dysfunction, and ABC is frequently accompanied by pathological fractures.A higher postoperative recurrence rate is related to a larger cyst size and the active and invasion phases of the cyst, but gender, age, the distance from the cyst to the epiphyseal plate and pathological fractures are not significantly related to the postoperative recurrence rate.