Objective To establish a scald-induced pain model using a constant-temperature electrical scald instrument in rats.Methods Thirty-six pathogen-free male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into 4 groups (n =9 each) using a random number table: control group (group C), scald for 5 s group (group S5), scald for 10 s group (group S10), and scald for 15 s group (group S15).The rats were anesthetized with intraperitoneal chloral hydrate.In S5, S10 and S15 groups, the plantar surface of the left hindpaw of rats were exposed to a constant-temperature electrical scald instrument (85 ℃) for 5, 10 and 15 s, respectively.The plantar surface of the left hindpaw of rats was exposed to an electrical scald instrument (room temperature) for 10 s in group C.At 1 day before treatment (T0),and 1, 3, 5, 7 and 14 days after treatment (T1-5), the mechanical and thermal pain thresholds were measured.Immediately after treatment, and at 24 h after treatment, the total body condition, wound color, and shape of the margin of the wound were observed and recorded.At 24 h after treatment, 3 rats were randomly sacrificed, and the skin from the plantar surface of the left hindpaw was removed for microscopic examination.Results Compared with group C, the thermal pain threshold at T1-2, and the mechanical pain threshold at T1-3 were significantly decreased in group S5, and the thermal pain threshold,and mechanical pain threshold were significantly decreased at T1-4 in group S10 (P＜0.05).The thermal pain threshold ＞ 25 s, and the mechanical pain threshold ＞30 g at T1-5 in group S15.The swelling in foot was bovious, burn blister appeared, and the degree of damage was aggravated in group S10 compared with S5 and S15 groups.Conclusion The scald-induced pain model is successfully established using a constant-temperature electrical scald instrument in rats.

Objective:To explore the clinical effect of the 3D printing pre-installed screw channel model in assisting screw placement of single complete segmented congenital hemivertebrectomy.Methods:Clinical data of 13 children treated with single complete segmented congenital hemivertebrectomy in the Department of Spine and Spinal Surgery of Henan Provincial People′s Hospital from August 2016 to January 2019 were retrospectively analyzed.Among them, there were 5 males and 8 females with the mean age of 9.9 (5-14) years.Categorized by the lesion location, 3 cases were located at T 9, 2 cases at T 10, 5 cases at T 11, 1 case at T 12, and 2 cases at L 1.During the operation, the 3D printing pre-installed screw channel model was used to assist the placement of pedicle screws.The accuracy of screw placement was assessed by the postoperative CT.All children were routinely examined by full-length anterior and lateral X-ray of spine in the standing position before and after surgery to measure the Cobb angles at the coronal and sagittal view.Furthermore, the correction rate of scoliosis and kyphosis after surgery and during follow-up was also calculated.The One-Way repeated measures ANOVA was used to compare the Cobb angle of scoliosis and kyphosis before surgery, after surgery and during follow-up. Results:A total of 85 pedicle screws were placed in 13 children, with the accuracy rate of screw placement of 95.3%.The mean surgery time and intraoperative blood loss were (216.9±28.3) min, and (478.5±132.6) mL, respectively.Scoliosis Cobb was corrected from (57.1±12.7)° to (12.7±4.7)° with a correction rate of (78.4±5.9)%, which was (14.2±7.0)° at the last follow-up.Kyphosis angle was corrected from (46.2±8.4)° to (13.2±4.4)° with a correction rate of (72.6±7.0)%, which was (14.0±3.4)° at the last follow-up.None of the children had serious complications like vascular and nerve damage.The mean postoperative follow-up was 12.3 (6-18) months.No significant loss of angle was detected during the follow-up period.There were significant differences in the lateral and kyphotic angles after surgery and during follow-up compared with preoperative ones (all P<0.05). No significant difference was detected between the postoperative lateral and kyphotic angles and those at the last follow-up (all P>0.05). Conclusion:The 3D printing pre-installed screw channel model used to assist screw placement of single complete segmented congenital hemivertebrectomy can improve the precision of screw placement and the orthopedic effect on lateral kyphosis.

Objective:To explore the accuracy and repeatability of the smartphone scoliosis screening APP developed by our team in the measurement of the Cobb angle of adolescent idiopathic scoliosis (AIS).Methods:Clinical data of 60 patients with AIS admitted to Department of Spine and Spinal Surgery, Henan Province People′s Hospital from August 2020 to February 2021 were analyzed retrospectively.Three surveyors measured the coronal main curvature Cobb angle, sagittal thoracic kyphosis (TK) angle, thoracolumbar kyphosis (TLK) angle and lumbar kyphosis (LL) angle on whole-spine lateral X-ray films of 60 patients with AIS by means of the protractor, scoliosis screening APP and computerized Picture Archiving and Communication System (PACS). The time and results of each measurement were recorded.The measurement was repeated once after 2 weeks.Paired t-test was used to compare the measurement time of the APP method and the protractor method.Taking the Cobb angle measurement results of the PACS system as the reference standard, the accuracy of Cobb angle measurement by the APP method was analyzed by paired t-test.The repeatability of the surveyor and the consistency between the surveyors was compared by intraclass correlation coefficient (ICC). Results:Among the 60 patients with AIS, there were 17 males and 43 females, aged from 10 to 16 years [(12.2±2.4) years]. The main bends were thoracic curvature (Lenke Ⅰ) in 23 cases, Lenke Ⅱ in 18 cases and thoracolumbar curvature/lumbar curvature (Lenke V) in 19 cases.The APP method took significantly less time to measure the Cobb angle than the protractor method ( P<0.05). There was no significant difference in the Cobb angle measured by the APP method and PACS method ( P>0.05). The results of the coronal main curvature Cobb angle, TK angle, TLK angle and LL angle measured by 3 surveyors through the APP method were all in good agreement (ICC=0.990, 0.988, 0.986, 0.987). The repeatability (ICC 0.973-0.982) of the coronal main curvature Cobb angle, TK, TLK and LL measured twice before and after the APP method were both better that of the protractor method (ICC 0.933-0.954). Conclusions:Compared with the traditional protractor, the smartphone scoliosis screening APP has the advantages of short measurement time, high efficiency, excellent accuracy and good repeatability in measuring the Cobb angle of AIS.