Objective:A C57/BL6 mouse model of traumatic temporomandibular joint ankylosis (TTMJA) was established through composite trauma to lay the foundation for studying the pathophysiology of TTMJA.Methods:This study was conducted from January 2024 to February 2025. Forty-two 4-weeks old C57/BL6 mice, numbered 1 to 42, are randomly assigned to a control group ( n=21) and an experimental group ( n=21) using a computer-generated random number sequence. The experimental group undergoes modeling surgery on the left temporomandibular joint (TMJ), while the control group is routinely raised without special treatment. At 12 weeks post-surgery, the TMJ complex of both groups is assessed via body weight and mouth opening measurements, gross observation, micro-CT, and histological staining to evaluate model establishment. Results:At 12 weeks post-operation, in the experimental group, the body weight of mice [(27.75±1.08) g] did not show a significant difference compared with that of the control group [(30.80±0.29) g]( t=0.54, P=0.610). The maximum vertical passive mouth opening [(1.70±0.26) mm] in the experimental group was significantly lower than that in the control group [(3.43±0.21) mm]( t=8.92, P<0.001). Gross observation indicated that the right TMJ structure of the experimental-group mice was normal, while irregular hyperplasia occurred in the left TMJ complex. Micro-CT revealed that at 12 weeks post-operation, the right joint structure of the experimental-group mice was normal, with regular condyles and glenoid fossae. On the left side, a large amount of bone hyperplasia occurred on the lateral side of the joint in the condyles and glenoid fossae, forming two irregular bone masses, and there was an uncalcified radiolucent zone between the bone masses. In histological staining, no new cartilage or bone tissue was observed in the left joint space of the control-group mice, and the articular disc structure was normal. In the experimental-group mice, obvious new cartilage and calcified bone tissue were visible on the lateral side of the left joint space. A bone bridge was formed between the condyles and glenoid fossae, the articular disc structure disappeared, and bony ankylosis occurred. Conclusions:In this experiment, a TTMJA model of C57/BL6 mice was initially established by removing the articular disc and damaging part of the fibrous cartilage of the glenoid fossae and condyles, providing an experimental platform for further research on the pathogenesis of TTMJA.

Objective:A C57/BL6 mouse model of traumatic temporomandibular joint ankylosis (TTMJA) was established through composite trauma to lay the foundation for studying the pathophysiology of TTMJA.Methods:This study was conducted from January 2024 to February 2025. Forty-two 4-weeks old C57/BL6 mice, numbered 1 to 42, are randomly assigned to a control group ( n=21) and an experimental group ( n=21) using a computer-generated random number sequence. The experimental group undergoes modeling surgery on the left temporomandibular joint (TMJ), while the control group is routinely raised without special treatment. At 12 weeks post-surgery, the TMJ complex of both groups is assessed via body weight and mouth opening measurements, gross observation, micro-CT, and histological staining to evaluate model establishment. Results:At 12 weeks post-operation, in the experimental group, the body weight of mice [(27.75±1.08) g] did not show a significant difference compared with that of the control group [(30.80±0.29) g]( t=0.54, P=0.610). The maximum vertical passive mouth opening [(1.70±0.26) mm] in the experimental group was significantly lower than that in the control group [(3.43±0.21) mm]( t=8.92, P<0.001). Gross observation indicated that the right TMJ structure of the experimental-group mice was normal, while irregular hyperplasia occurred in the left TMJ complex. Micro-CT revealed that at 12 weeks post-operation, the right joint structure of the experimental-group mice was normal, with regular condyles and glenoid fossae. On the left side, a large amount of bone hyperplasia occurred on the lateral side of the joint in the condyles and glenoid fossae, forming two irregular bone masses, and there was an uncalcified radiolucent zone between the bone masses. In histological staining, no new cartilage or bone tissue was observed in the left joint space of the control-group mice, and the articular disc structure was normal. In the experimental-group mice, obvious new cartilage and calcified bone tissue were visible on the lateral side of the left joint space. A bone bridge was formed between the condyles and glenoid fossae, the articular disc structure disappeared, and bony ankylosis occurred. Conclusions:In this experiment, a TTMJA model of C57/BL6 mice was initially established by removing the articular disc and damaging part of the fibrous cartilage of the glenoid fossae and condyles, providing an experimental platform for further research on the pathogenesis of TTMJA.

Harmine(HM)is a type of β-Carboline alkaloid abundant in nature and has many biological effects.In recent years.Studies have found that HM had a significant positive effect on Alzheimer's disease(AD)both in vivo and in vitro.Its mechanism may be related to the reduction of abnormal deposition of β-amyloid protein(Aβ),excessive phosphorylation of Tau protein,regulation of the cholinergic system,antioxidant stress,and antineuritis.This article reviews the research progress on the improvement effect and mechanism of HM in AD in order to provide an experimental basis for the clinical application of HM and the development of drugs in the area of AD the prevention and treatment.

Objective To evaluate the clinical efficacy of arthroscopic bursal layer-only double-row suture-bridge repair for delaminated rotator cuff tear which is difficult to reposit in comparison with separate double-layer repair and whole-layer repair.Methods From May 2013 through June 2016,82 patients with delaminated rotator cuff tear difficult to reposit were treated at Department of Joint Surgery,The Affiliate Hospital to Chengde Medical University.They were 47 males and 35 females with a mean age of 53.0 ± 7.9 years.They were divided into 3 groups according to their surgical procedures.In group A,28 cases were treated by arthroscopic whole-layer double-row suture-bridge procedure;in group B,29 cases were treated by arthroscopic separate double-layer double-row suture-bridge procedure;in group C,25 cases were treated by arthroscopic bursal layer-only double-row suture-bridge procedure.The 3 groups were compared in terms of University of California Los Angeles (UCLA) score,American Shoulder and Elbow Surgeons (ASES) score,visual analogue scale (VAS),Constant shoulder score,range of motion of shoulder joint and rotator cuff retear preoperatively and postoperatively.Results The patients in the 3 groups were comparable because their preoperative general data showed no significant significances (P ＞ 0.05).The operation time for groups A,B and C was respectively 105.5 ±5.6 min,117.4 ±6.9 min and 88.0 ±4.2 min,showing significant differences between the 3 groups (P ＜ 0.05).The 82 patients were followed up for 21 to 24 months (average,23.3 months).At 24 months postoperatively,UCLA,ASES,VAS,Constant score,shoulder anteflexion and lateral extorsion were respectively 32.4 ± 2.5,12.8 ± 0.9,1.0 ± 1.1,93.4 ± 5.6,158.3° ± 9.3°and 58.9°±5.0°in group A,32.2±2.5,12.9±1.0,0.9±1.0,92.8±6.0,156.4°±9.5°and 59.3°± 5.6° in groups B,and32.4±2.4,12.9±0.9,0.7±0.9,94.3±5.2,156.0°±9.5°and57.6°°5.4°in group C,showing no significant differences between the 3 groups (P ＞ 0.05).The occurrence of rotator cuff retear in groups A,B and C were respectively 17.9％ (5/28),13.8％ (4/29) and 12.0％ (3/25),showing no significant differences between the 3 groups (P ＞ 0.05).Conclusions In repair of delaminated rotator cuff tear difficult to reposit,although the arthroscopic bursal layer-only double-row suture-bridge repair is similar to conventional arthroscopic whole-layer double-row suture-bridge repair and arthroscopic separate double-layer double-row suture-bridge repair in functional recovery and range of motion of the shoulder and incidence of rotator cuff retear,it can reduce obviously operation time and make the operation easier.

Objective To analyze the clinical effects of arthroscopic en masse repair with footprint ending shift using double-row suture-bridge technique for delaminated rotator cuff tears under tension.Methods A total of 58 patients with delaminated rotator cuff tears under tension from August 2013 to August 2016 who underwent arthroscopic en masse repair using doublerow suture-bridge technique were retrospectively analyzed.There were 33 males and 25 females with a mean age of 53.0±7.8 years (range 39-74) with 24 patients left side involved and 34 right side.They were divided into 2 groups to receive en masse repair either footprint ending shift or on the footprint.There were 28 patients with footprint ending shift and 30 patients on the footprint.Clinical effects were evaluated by University of California Los Angeles (UCLA) score,American Shoulder and Elbow Surgeons (ASES) score,visual analogue scale (VAS),Constant-Murley score and shoulder range of motion at preoperatively and postoperatively.Results The average follow-up duration was 23.2±0.8 months (range 21-24).The two groups were compatible with no significant difference in age,gender,tear size,follow-up duration,preoperative function and range of motion of the shoulder joint (P＞0.05).At the last follow up,the UCLA,ASES,VAS,Constant-Murley scores and shoulder range of motion in the group footprint ending shift were respectively 32.4±2.5,12.8±0.9,1.0±1.1,93.4±5.6,158.3°±9.3°,58.9°±5.0° with significantly differences compared with preoperative scores (P ＜ 0.05).The postoperative value in the group on footprint were respectively 31.6±2.9,12.8±0.9,0.7 ± 1.2,91.3±7.1,156.1°± 10.7°,59.6°±4.6° with significantly differences compared with the preoperative scores (P ＜ 0.05).There were no significant difference between the two groups (P ＞ 0.05).The operation duration in the group footprint ending shift was 100.9±6.0 min,while that in the group on footprint was 106.6±6.1 min.There was significantly difference in the operation duration between two groups (t=-3.600,P=0.001).Conclusion Arthroscopic en masse repair using double-row suture-bridge technique can successfully treat delaminated rotator cuff tears under tension.Compared with arthroscopic en masse repair on footprint using double-row suture-bridge technique,the footprint ending shift is easier and time saving without significant difference in function of the shoulder joint and the range of motion in repair of delaminated rotator cuff tear under tension.