BACKGROUND:Flexible intramedulary nailing and external fixation for pediatric femoral shaft fractures are two common methods in the clinic. It remains controversial which fixation methods are better. OBJECTIVE:To systematicaly evaluate the therapeutic effects of flexible intramedulary nailing and external fixation for pediatric femoral shaft fractures. METHODS: A computer-based search was performed on PubMed, Embase, Medline, and Cochrane library for literatures on clinical controled trials of flexible intramedulary nailing and external fixation for pediatric femoral shaft fractures published before November 25, 2014. Literature language was not limited. The age of subjects was from 3 to 15 years. Modified Jadad was utilized to assess methodological quality of the included studies. Meta-analysis was carried out using Stata 12.0 software. RESULTS AND CONCLUSION:Six papers involving 237 patients were included. Meta-analysis results showed that compared with external fixation, a low incidence of overal complications [relative risk (RR)=0.30, 95% confidence interval (CI): 0.19-0.46;P < 0.001] and pin-hole infection (RR=0.286, 95%CI: 0.13-0.61;P= 0.001), but a high risk of needle tail irritation (RR=1.86, 95%CI: 1.35-2.56;P < 0.001) were found folowing flexible intramedulary nailing. No significant differences in other complications were found between the two groups. These results confirm that compared with external fixation, elastic intramedulary nail has fewer complications and faster fracture healing. Elastic intramedulary nail is recommended for single pediatric femoral shaft fractures. However, external fixation is a better option for high energy injury of lower limbs, multiple trauma or severely soft tissue injury.

Objective: To investigate the effectiveness of local subcutaneous pedicled fat flap filling and separation of the synostosis area associated with radial shortening osteotomy and plate internal fixation for the treatment of congenital radioulnar synostosis. Methods: Between February 2014 and June 2018, 36 patients (41 sides) with congenital radioulnar synostosis were analyzed retrospectively, including 21 males and 15 females, aged 2.5-4.5 years with an average of 3.1 years. The fixed pronation deformity of the forearm ranged from 30° to 90° with an average of 71.6°, and the range of motion of the elbow flexion was 120°-135° with an average of 128.2°. According to the Cleary-Omer classification, there were 8 sides of type Ⅱ, 17 sides of type Ⅲ, and 16 sides of type Ⅳ. All patients were treated by local subcutaneous pedicled fat flap filling and separation of the synostosis area associated with radial shortening osteotomy and plate internal fixation. The range of motion of the elbow, muscle strength, joint stability, and patient discomfort were evaluated by using the Broberg and Morrey elbow scoring system preoperatively and postoperatively. In addition, the ability for daily living of the affected limb was evaluated by using the Failla grading standard. Results: Radial nerve palsy occurred in 3 cases, and nerve function recovered at 2-4 weeks after operation. All the 36 cases were followed up 6-52 months, with an average of 38 months. All osteotomy sites healed, the healing time was 5-12 weeks (mean, 6.3 weeks), and the pedicled fat flap between the radius and ulna survived when the internal fixation was taken. At last follow-up, the flexion range of motion of elbow joint was not decreased, and the pronation and supination range of motion of forearm were improved. The elbow flexion range of motion was 125°-135° with an average of 132.4°. The pronation range of motion of forearm was 15°-45° with an average of 30.1°, and the supination range of motion of forearm was 10°-40° with an average of 22.6°. At last follow-up, the Broberg and Morrey elbow scores increased from the preoperative 85.6±1.0 to 91.8±1.8, showing significant difference ( t=25.593, P=0.000). Moreover, the results were good in 3 sides, fair in 9 sides, and poor in 29 sides according to the Failla grading standard before operation, with an excellent and good rate of 7.3%. At last follow-up, the results were excellent in 6 sides, good in 28 sides, and fair in 7 sides, with an excellent and good rate of 82.9%, showing significant difference when compared with preoperative value ( Z=-5.781, P=0.000). Conclusion: The application of local subcutaneous pedicled fat flap filling and separation of the synostosis area associated with radial shortening osteotomy and plate internal fixation is an effective surgical method for the treatment of congenital radioulnar synostosis. It can restore the partial rotation function of the forearm and improve the quality of life of children.

Objective: To explore the clinical effect of double-wing flap for the treatment of toe syndactyly. Methods: Retrospective analysis of 47 patients (60 syndactyly toes) who underwent double-wing flap to reconstruct toe web space in orthopedics department of the Third Affiliated Hospital of Zhengzhou University from February 2010 to October 2017.There were 21 males and 26 females, with an average age of 18.9 months (range: 10-48 months). All patients were treated with zigzag incisions to separate the toe syndactylys without skin grafts.The condition of wound healing and appearance of toes were observed. Results: The average follow-up time was 62.3 months (range: 6 to 80 months). There were no complications such as hematoma, infection, flap necrosis and no flexion contracture and obvious scar hyperplasia in all the 47 cases, 4 of the 60 webs developed web creep.All webs had good appearance with 45 degrees inclination from the dorsal to the metatarsal side and had good flexion and abduction function. Conclusions The double-wing flap is a simple and safe operation for toe syndactyly which has a good clinical effect.

Objective: To introduce a new surgical technique for the correction of congenital syndactyly without skin grafts. Methods: The technique consists of a dorsal double-wing flap created from the dorsal skin of the metacarpophalangeal joint to cover the newly released web space and zigzag incisions in the fingers, thus avoiding the use of skin grafts in this area. Results: From May 2010 to October 2016, 35 web spaces in 24 patients were treated using this technique. There were no complications such as haematoma, infection or flap necrosis. The average follow-up time was 54 months (range, 6 months to 60 months). One of the 35 webs developed web creep. No patients developed flexion contractures. All webs had good appearance with 45 degrees inclination from dorsal to palmar. All fingers had no obvious scar, and the flexion and abduction function were good. Conclusions The technique is simple, rapid, safe and easily performed and does not require the use of skin grafts.

Objective:To investigate the clinical value of iodine density map and low keV virtual monoenergetic images (VMI) derived from dual-layer spectral detector CT (DLCT) for the pancreatic neuroendocrine tumors (pNETs) detection.Methods:From January to June 2019, data of 23 pathologically confirmed patients of pNETs were retrospectively analyzed. All of the patients underwent pancreas enhanced DLCT scanning within 1 week before surgery. The conventional polyenergetic images (PI), iodine density map and 40, 50, 60, 70 keV VMI were generated. One resident radiologist with 3 years’ experience and one senior radiologist with over 10 years’ experience interpreted the images for the lesion detection independently using the following image series: PI, VMI (40-70 keV), PI combined with iodine density map. Lesion detection rates were recorded and compared among different image series. The CT value and noise of lesion, normal pancreatic parenchyma, and abdominal subcutaneous fat were measured in PI and VMI in both arterial and portal vein phases. The contrast-to-noise ratio (CNR) of lesion was calculated. The CT value of lesion and normal pancreatic parenchyma, CNR of lesion, and image noise were compared using repeated one-way ANOVA test. Subjective image quality was assessed with a 5-point scale and compared with Friedman test.Results:A total of 26 lesions were confirmed from 23 patients. For resident radiologist and senior radiologist, the detection rates of pNETs lesion using PI were 76.9% (20/26) and 84.6% (22/26) respectively, and both improved to 92.3% (24/26) using image series of 40 and 50 keV VMI. For senior radiologist, the pNETs lesion detection rate was further improved to 96.2% (25/26) using image series of PI with iodine map. The CT value of lesion and normal pancreatic parenchyma, CNR, and image noise had statistical differences among PI and VMI (40-70 keV) in both arterial and portal vein phase ( P<0.001). The mean CT attenuation and CNR of lesion in VMI increased significantly as the energy level decreased.The CNR of lesion in all VMI (40-70 keV) was significantly higher than that in PI. The median of subjective scores of image quality in PI and VMI (40-70 keV) were 3, 3, 4, 4, and 5 respectively, and the difference was statistically significant (χ2=66.393, P<0.001). Conclusions:The low keV VMI derived from DLCT can increase the CT value and CNR of pNETs, and the lesion detection rate can be improved combined with iodine density map. The CNR of pNETs is the highest in 40 keV VMI, and image noise is still lower than that of PI, so 40 keV VMI is recommended for clinical application.

Objective:To explore the image quality of 40 keV virtual monoenergetic images (VMI) derived from dual-layer spectral detector CT （DLCT） pancreas dynamic enhanced scanning and its optimal window setting.Methods:From January to July 2019, 28 patients who underwent pancreas enhanced DLCT scan within one week before surgery and pathologically confirmed of pancreatic neuroendocrine tumors (pNETs) were retrospectively enrolled. Conventional polyenergetic images (PI) and 40 keV virtual monoenergetic images （VMI 40 keV） were generated after scanning.CT value of normal pancreatic parenchyma, lesion, abdominal subcutaneous fat, abdominal aorta and portal vein were measured in PI and VMI 40 keV. The contrast-to-noise ratio (CNR) of the pNETs lesion was calculated. All these objective results were compared between VMI 40 keV and PI using paired ttest. Individual window settings （W-Ind, including window width and window level） of VMI 40 keVwere recorded. Calculated window settings （W-Calc） were mathematically calculated via regression analysis and optimized window settings （W-Opt） were obtained.Subjective image quality was assessed with a 5-point scale and compared among VMI 40 keV with different window settings (W-Std, W-Ind, W-Calc and W-Opt) using Friedman test, and compared PI with standard abdominal window setting (W-Std) and VMI 40keV with W-Opt settings using Wilcoxon test.The maximum diameter of lesion was measured and compared with one-way ANOVA analysis among PI and VMI 40 keV with different windows settings. Results:For VMI 40 keV in both arterial phase and portal vein phase, the CT attenuation [(464.0±136.7), (375.4±79.2) HU] of pNETs lesion were statistically significantly higher than those in PI [（168.8±38.0), (140.5±23.5) HU] （ t=-16.107,-22.225, P<0.001）, CNR （16.5±11.1, 10.9±6.1） were also statistically significantly higher than those in PI （4.5±2.9, 3.0±1.9） （ t=-7.838, -9.781， P<0.001）,while with lower image noise in VMI 40 keV[（11.8±1.5),(11.8±1.4) HU] than PI （13.1±1.5,12.9±1.3 HU）（ t=6.356,3.891， P<0.001）. The subjective score for PI with W-Std and VMI 40 keV with W-Std, W-Ind, W-Calc, W-Opt in arterial phase were 4（1）, 1（0）, 5（0）, 5（0.75）, 5（1）, and which in portal vein phase were 3.5（1）, 1（0）, 5（0）, 5（0）, 5（1）.The subjective score of VMI 40 keV with different window settings had statistical differences （χ 2=76.143,76.000， P<0.001）. Compared to the image quality of PI with W-Std settings, VMI 40 keV with W-Opt settings have higher objective score （ Z=4.685, 4.235， P<0.001）. The maximum diameter of lesion has no statistical difference among PI and VMI 40 keV with different window settings （ F=0.008, 0.004， P>0.999） in both arterial phase and portal vein phase. Conclusions:The VMI 40 keV in pancreas dynamic enhancement scanning derived from dual-layer spectral detector CT have higher image quality than PI. Due to changes of CT value of tissue in VMI 40 keV, it is recommended to optimize window settings （window width/window level， 880/230 HU for arterial phase and 840/260 HU for portal vein phase） to obtain the best image quality.

Objective To explore the feasibility of the virtual non-contrast images derived from dual-layer spectral detector CT (SDCT) substitute for true non-contrast images.Methods From July 2017 to September 2017,40 patients under-went pre-and arterial-venous dual-phase post-contrast abdominal imagining on a SDCT in Shanghai Jiaotong University School of Medicine Affiliated Ruijin Hospital.The images were retrospectively analyzed.The arterial VNC images (VNC-a) and venous VNC images (VNC-v)were derived from spectral based image (SBI) datasets of arterial and portal venous phase using a dedicated software respectively.Then mean CT attenuation,mean image noise,signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared with one-way ANOVA analysis among TNC,VNC-a,VNC-v images in liver,spleen,pancreas,abdominal aorta,inferior vena cava,psoas muscle,L4 vertebra and perirenal fat.And Bland-Altman plots was used to analyze the CT attenuation equivalence between TNC and VNC.Subjective image quality was assessed with a 5-point scale and compared with Friedman H test.The dose length product (DLP) of pre-and post-contrast scans were recorded.Results The CT attenuation of abdominal aorta,perirenal fat,L4.vertebra among three kinds of images had significant differences (P＜0.05)which overestimated the CT attenuation of perirenal fat and underestimated CT attenuation of abdominal aorta and vertebra compared to TNC,VNC.Except for pancreas,the image noise of all other tissues among three kinds of images had significant differences,images noise of VNC images were lower than TNC images (P＜0.05).The SNR of liver,spleen,psoas muscle and inferior vena cava and CNR of pancreas,abdominal aorta,inferior vena cava,L4 vertebra and perirenal fat were statistically significant among the three images (P＜0.05).Except for vertebra and perirenal fat,good equivalence between VNC and TNC images were observed in all relevant tissues with Bland-Altman analysis.Image quality subjective scoring of TNC,VNC-a,and VNC-v were 5.00(1.00),5.00(0.75),5.00(1.00) respectively which had no significant differences (P=0.20).The DLP of TNC,arterial and venous phase scan were (255.2±62.0),(258.9±62.9),(252.0±61.2)mGy·cm,and the total DLP of dual-phase contrast enhanced scan was (766.2± 185.3) mGy· cm.The DLP of TNC accounted for 33.3％(255.2/766.2) of the total DLP,and effective dose of TNC was (3.83±0.90)mSv.Conclusions CT attenuation in VNC image which exhibited lower image noise was identical to TNC images in the majority of abdomen tissues except for vertebra and perirenal fat.and the VNC image.The VNC image which reduces radiation dosage derives from SDCT enhanced image might be used as a substitute for the TNC image.

Objective:To evaluate the deformity changes in the treatment of congenital clubfoot in infants by ultrasound, and to explore its clinical application value.Methods:Seventeen infants with congenital clubfoot treated in the Department of Pediatric Orthopaedics of the Third Affiliated Hospital of Zhengzhou University from March 2020 to June 2021 and 27 normal infants in the same period were selected. The distance between medial malleolus and scaphoids (MM-N distance) of all feet was measured by ultrasound. The distance from the tangent line of the lateral edge of calcaneus to the midpoint of the lateral edge of the chondroid bone (C-C distance), medial soft tissue thickness and tibial calcaneal angle were measured by ultrasound. The data before, after treatment and during follow-up were statistically analyzed.Results:A total of 88 feet of 44 infants were evaluated. The mean number of cast was 4.7±1.1, the follow-up time was (96.9±59.3)days. The MM-N distance, C-C distance and posterior tibial calcaneal angle in the clubfoot group were improved after treatment and at the last follow-up, and the differences were statistically significant (all P<0.01). During the treatment, 1 case had false correction, and 2 cases recurred in the last follow-up. Conclusions:Ultrasound can clearly display the medial, dorsal, lateral and posterior articular structures of normal and clubfoot, and can observe the deformity changes of clubfoot during the correction process, which can provide guidance for the clinical treatment of clubfoot.