BACKGROUND:Lumbar fixed-point rotation operation needs collaborative operation of the doctor's hands,and outputs rotation and thumb thrust.Lumbar disc herniation can be treated through disc displacement and adjusting stress distribution.However,the mechanical effects of thumb thrust and the biomechanical effects of loading direction on manipulative effects remain unclear. OBJECTIVE:To compare the biomechanical difference of lumbar fixed-point rotation manipulation for treating lumbar disc herniation under different thrust directions. METHODS:The L3-5 normal three-dimensional finite element model was constructed and validity was verified.According to the intervertebral disc degeneration Pfirrmann grade,intervertebral disc degeneration was simulated by modifying the L4/5 intervertebral space height,the volume of the nucleus pulposus,as well as the material parameters of the annulus fibrosus,nucleus pulposus,and ligament.Finally,the pathological model of L4/5 moderate disc degeneration with left para-central herniation was constructed,and then the pathological models were used as research objects.Simulation technique:spinning to the right;taking the condition on changing the direction of the thumb thrust to establish three modes of operation(M1:thumb push to the left;M2:thumb push to the right;M3:no thrust push).The protrusion displacement and the disc stress,and the stress and strain of the facet joint cartilage were compared in the three operating modes. RESULTS AND CONCLUSION:(1)Maximum displacement value of L4/5 disc herniation:displacement was 2.672 3 mm for M1,1.156 1 mm for M2,1.826 4 mm for M3,M1＞M3＞M2.(2)The maximum Von Mises stress of L4/5 discs was 1.846 7 MPa for M1,0.419 0 MPa for M2,and 1.257 9 MPa for M3,M1＞M3＞M2.(3)L4/5 bilateral small cartilage produced different degrees of contact stress changes:It was 0.485 5 MPa for M1,0.026 7 MPa for M2,and 0.441 4 MPa for M3,M1＞M3＞M2.Right cartilage contact force was 0.000 5 MPa for M1,0.025 9 MPa for M2,and 0.001 3 MPa for M3,M2＞M3＞M1;the left greater than the right,M1 had the highest value;cartilage strain was consistent with contact stress changes.(4)Different operation modes will have some biomechanical influences on the diseased intervertebral disc and accessory structure.The M1 operation mode can maximize the displacement of protrusion,disc stress and left joint cartilage contact,which can better promote disc displacement,balance stress distribution and reduce facet joint disorder,so the operation is better.

[This corrects the article DOI: 10.1016/j.apsb.2024.04.021.].

Objective:To explore the clinical effect of radial extracorporeal shockwave therapy on delayed union of forearm fractures in children with ultrasonic guidance.Methods:A retrospective analysis of information on 18 children with delayed forearm fracture union who received ultrasonic guided extracorporeal shockwave therapy from February 2018 to June 2019 was conducted. Among them, there were 14 males and 4 females; Age: 9.44±3.75 years (range, 3-15 years); All the children were closed forearm fractures, including 13 cases of ulna and 5 cases of radius. Initial fixation methods: intramedullary nails fixation in 8 cases, Kirschner wire fixation in 4 cases, steel plate fixation in 2 cases, external fixation in 2 cases, conservative treatment in 2 cases; The classification of fracture nonunion were: 14 cases of hypertrophy, 4 cases of atrophy; The course of disease was 4.0 (3.0, 6.0) months. The front and lateral X-ray films of the affected side forearm were taken before treatment, 3 months and 6 months after treatment. The scores of callus condition were performed using Lane-Sandhu X-ray scoring standard and Fernandez-Esteve X-ray evaluation standard of callus grade.Results:All children completed treatment and were followed up for 6 months. The bone healing standard was the disappearance of the fracture line shown by anterior and lateral X-ray films. Within 6 months after treatment, 11 patients got bone union. The healing rate was 61.11% (11/18). The average of Lane-Sandhu X-ray scores before treatment, 3 months and 6 months after treatment were 3.0 (1.0, 4.0), 6.0 (4.0, 8.0) and 10.0 (5.0, 12.0), respectively, there were statistically significant differences in pairwise comparisons at each time point. And the average scores of Fernandez-Esteve X-ray evaluation standard for callus grade were 1.0 (1.0, 2.0), 3.0 (2.0, 4.0), and 4.0 (3.0, 4.0), respectively, there were statistically significant differences from 3 months and 6 months after treatment to preoperative group, while there was no statistically significant difference between 3 months and 6 months after treatment. The mixed effects model analysis results showed that only the Lane Sandhu X-ray score and Fernandez Esteve X-ray standard score of callus grade at different follow-up time points were significantly different. There was no statistically significant difference in age, gender, number of shockwave treatments and interval time from the first treatment after the initial fixation.Conclusion:The radial extracorporeal shockwave therapy can effectively treat the delayed healing of forearm fractures in children; the X-ray score has been significantly improved. The treatment is highly accepted by children and their parents, and can be used as one of the methods to treat delayed healing of fractures in children in the future.

Objective:To study the a feasibility of modified pharyngoplasty in the treatment of velopharyngeal insufficiency.Methods:30 cases of velopharyngeal insufficiency were treated with a modified pharyngoplasty followed by speech training.The effects of the treatment were evaluated by blowing test (BT),chinese articulation inteligibility test (CIT) and hypernasality observation(HO).Results:Before and after treatment BT was 1～26 and 8～40,CIT(%) 20～60 and 47～82,HO(cases) 30 and 3,respectively.Conclusions:The modified pharyngoplastic surgery is feasible in the treatment of velophayngeal insufficiency.