【Abstract】 Objective To explore the methods and appl ication value of surface shaded display (SSD) and multiplanarreconstruction (MPR) in the evaluation of acetabular morphology in patients with developmental dysplasia of the hip (DDH) before total hip arthroplasty (THA). Methods From October 2003 to November 2006, 17 patients (3 males and 14 females, aging from 35 years to 61 years) with osteoarthritis secondary to DDH were scanned with spiral CT preoperatively. According to the Crowe standard, 19 dysplasia hips were classified as type I in 4 hips, type II in 9 hips, type III in 6 hips. The obtained hip CT data were developed with SSD and MPR to observe spational position and bone stock of the acetabula. Results The dislocated extent was 25%-89% in these dysplasia hips according to the Crowe method and their sharp angles all exceeded 45°. Bone defect occurred to each of the acetabula, among which it was located in anterosuperior acetabulum in 5 hips, in superolateral acetabulum in 11 hips and in posterosuperior acetabulum in 3 hips. The hip images made with MPR showed that the minimum thickness of the medial wall of acetabula ranged from 2.0 mm to 10.9 mm. Among 15 unilateral dysplasia patients, the opening difference anddepth difference between the dysplasia acetabulum and the contralateral one ranged from 2.7 mm to 19.1 mm and from 2.3 mm to 13.1 mm, respectively. Conclusion SSD and MPR of spiral CT are effective methods in evaluating acetabular morphology preoperation and contribute to intraoperative acetabular reconstruction in patients with DDH performed THA.
ObjectiveTo study a deep learning-based dual-modality fundus camera which was used to study retinal blood oxygen saturation and vascular morphology changes in eyes with branch retinal vein occlusion (BRVO). MethodsA prospective study. From May to October 2020, 31 patients (31 eyes) of BRVO (BRVO group) and 20 healthy volunteers (20 eyes) with matched gender and age (control group) were included in the study. Among 31 patients (31 eyes) in BRVO group, 20 patients (20 eyes) received one intravitreal injection of anti-vascular endothelial growth factor drugs before, and 11 patients (11 eyes) did not receive any treatment. They were divided into treatment group and untreated group accordingly. Retinal images were collected with a dual-modality fundus camera; arterial and vein segments were segmented in the macular region of interest (MROI) using deep learning; the optical density ratio was used to calculate retinal blood oxygen saturation (SO2) on the affected and non-involved sides of the eyes in the control group and patients in the BRVO group, and calculated the diameter, curvature, fractal dimension and density of arteriovenous in MROI. Quantitative data were compared between groups using one-way analysis of variance. ResultsThere was a statistically significant difference in arterial SO2 (SO2-A) in the MROI between the affected eyes, the fellow eyes in the BRVO group and the control group (F=4.925, P<0.001), but there was no difference in the venous SO2 (SO2-V) (F=0.607, P=0.178). Compared with the control group, the SO2-A in the MROI of the affected side and the non-involved side of the untreated group was increased, and the difference was statistically significant (F=4.925, P=0.012); there was no significant difference in SO2-V (F=0.607, P=0.550). There was no significant difference in SO2-A and SO2-V in the MROI between the affected side, the non-involved side in the treatment group and the control group (F=0.159, 1.701; P=0.854, 0.197). There was no significant difference in SO2-A and SO2-V in MROI between the affected side of the treatment group, the untreated group and the control group (F=2.553, 0.265; P=0.088, 0.546). The ophthalmic artery diameter, arterial curvature, arterial fractal dimension, vein fractal dimension, arterial density, and vein density were compared in the untreated group, the treatment group, and the control group, and the differences were statistically significant (F=3.527, 3.322, 7.251, 26.128, 4.782, 5.612; P=0.047, 0.044, 0.002, <0.001, 0.013, 0.006); there was no significant difference in vein diameter and vein curvature (F=2.132, 1.199; P=0.143, 0.321). ConclusionArterial SO2 in BRVO patients is higher than that in healthy eyes, it decreases after anti-anti-vascular endothelial growth factor drugs treatment, SO2-V is unchanged.
Objective To study the anteromedial cortical morphology of intertrochanteric fracture with CT three-dimensional reconstruction technique, and to provide a reference for further study of cortical buttress reduction theory. Methods CT data of 75 patients with unstable intertrochanteric fracture with complete imaging data treated between January 2016 and January 2019 were retrospectively analyzed, including 32 males and 43 females, aged 65-98 years (mean, 79.8 years). According to AO/Orthopaedic Trauma Association typing of 2018 edition, there were 46 cases of 31-A2.2 type and 29 cases of 31-A2.3 type. The image processing techniques such as segmentation modeling and virtual reset were performed. The thickness of the cortex at the anteromedial corner, the angle between the anterior wall fracture line and the coronal horizontal line, the angle between the medial wall fracture line and the sagittal horizontal line, the width of the cortex supported by the medial wall were measured, and the morphology of the cortical bone at the anteromedial corner were observed. Results The angle between the anterior wall fracture line and the coronal horizontal line was 51.8-72.6°, with an average of 62.4°; the angle between the medial wall fracture line and the sagittal horizontal line ranged from 17.6° to –47.3°, with an average of −15.8°; the thickness of the cortex at the anteromedial angle was 3.6-6.1 mm, with an average of 4.4 mm; and the width of the cortex supported by the medial wall was 14.3-21.2 mm, with an average of 16.8 mm. The morphology of the cortical bone at the anteromedial corner had 3 forms: angle with femoral neck axis >90°, 57 cases (76.0%); perpendicular to femoral neck axis, 7 cases (9.3%); angle with femoral neck axis <90° (including reverse angle), 11 cases (14.7%). Conclusion CT three-dimensional reconstruction can clearly show the cortical morphology and the direction of the fracture line of intertrochanteric fracture, which can indicate the stability of the intertrochanteric fracture after reduction, and has a good guiding on the form of cortical buttress reduction.
OBJECTIVE: To establish the animal models of mandibular distraction osteogenesis in rabbits and study its osteogenetic mechanism. METHODS: The right mandibles just anterior to the first molars of 12 rabbits were performed osteotomies, and the mandibles were positioned with distractors. The left mandibles were control group without operation. After 1 week, the distractors were stretched 0.9 mm every day for 10 days progressively. One day, 2, 4, 8 weeks after distraction, the mandibles were studied with gross measurement, X-ray, and histological examination. RESULTS: The right mandible were lengthened 8.3 mm on average without bone nonunion and deformity healing. It was observed that the gaps between the distracted bone edges were first occupied by fibrous tissue. Two weeks after distraction, it was found that the gaps were bridged by callus in X-ray, the new bone and the normal bone could not be differentiated clearly after 8 weeks. In histological sections, there were collagen bundles in early distraction, then those collagen bundles were calcificated and become trabeculaes. No Cartilage was found during distraction. CONCLUSION: It suggests that the rabbit mandible can be lengthened by distraction osteogenesis, and the new bone is formed by intramembranous ossification.
In order to improve the interfacial bonding strength of hydroxyapatite/polyurethane implanted material and dispersion of hydroxyapatite in the polyurethane matrix, we in the present study synthesized nano-hydroxyapatite/polyurethane composites by in situ polymerization. We then characterized and analyzed the fracture morphology, thermal stability, glass transition temperature and mechanical properties. We seeded MG63 cells on composites to evaluate the cytocompatibility of the composites. In situ polymerization could improve the interfacial bonding strength, ameliorate dispersion of hydroxyapatite in the properties of the composites. After adding 20 wt% hydroxyapatite into the polyurethane, the thermal stability was improved and the glass transition temperatures were increased. The tensile strength and maximum elongation were 6.83 MPa and 861.17%, respectively. Compared with those of pure polyurethane the tensile strength and maximum elongation increased by 236.45% and 143.30%, respectively. The composites were helpful for cell adhesion and proliferation in cultivation.
In order to conduct surface monitoring of the three-dimensional spine morphology of the human body in daily life, a spine morphology measuring method using "single camera, multi-view" to construct stereo vision is proposed. The images of the back of the human body with landmarks of spinous process are captured from multiple angles by moving a single camera, and based on the "Zhang Zhengyou calibration method" and the triangulation principle of binocular stereo vision, the spatial conversion matrices corresponding to each other between all images and the 3D coordinates of the landmarks are calculated. Then the spine evaluation angle used to evaluate the spine morphology is further calculated. The tests’ results showed that the spine evaluation angle error of this method is within ±3°, and the correlation between the results and the X-ray film Cobb angles is 0.871. The visual detection algorithm used in this paper is non-radioactive, and because only one camera is used in the measurement process and there is no need to pre-set the camera's shooting pose, the operation is simple. The research results of this article can be used in a mobile phone-based intelligent detection system, which will be suitable for the group survey of scoliosis in communities, schools, families and other occasions, as well as for the long-term follow-up of confirmed patients. This will provide a reference for doctors to diagnose the condition, predict the development trend of the condition, and formulate treatment plans.
In order to investigate the histological and stereological change of the rapidly expanded skin tube, 15 Japanese Long Ear Rabbits were divided into 3 groups: (1) Rapid expansion group, injecting once a day for 7 days; (2) Routine expansion group, injecting every 3 days for 21 days and (3) Control group, no expander implanted. The results showed that: in the rapid expansion group, the thickness of the epidermis and dermis were both increased, fibroblast proliferation was active, a large amount of new capillaries was observed, the collagen fiber was in loose type, and the mitochondria and rough endoplasmic net of epithelial cell were increased. In the routine expansion group, similar changes were observed. The vascular density and volume fraction were significantly higher in rapid expansion group than those in the control group (P lt; 0.05). It was concluded that the rapid expansion of skin tube was feasible.
From June 2002 to December 2023, there were 5 patients with criss-cross admitted to the General Hospital of the Northern Theater Command, including 3 males and 2 females, aged 18 months to 25 years, and weighing 13-49 kg. There were 5 patients of atrioventricular position, 3 patients of right ventricular loop, 2 patients of left ventricular loop, 3 patients of normal atrioventricular connection, and 2 patients of inconsistent connection. Combined intracardiac malformations: 1 patient of simple ventricular septal defect combined with pulmonary hypertension, 1 patient of corrected transposition of the great arteries combined with ventricular septal defect, atrial septal defect, and pulmonary artery stenosis, 1 patient of corrected transposition of the great arteries combined with ventricular septal defect, atrial septal defect, and left atrioventricular valve insufficiency, and 2 patients of right ventricular double outlet combined with ventricular septal defect and pulmonary artery stenosis. The surgical methods included 2 patients of intracardiac anatomical correction, 1 patient of bidirectional vena cava pulmonary artery anastomosis, and 2 patients of total extracardiac ductal cava pulmonary artery anastomosis. All 5 patients were discharged smoothly.
Suture broken, knot slipping and tissue tearing are the main reasons of wound closure failure in clinical operation. Based on this, we simulated the suturing and healing operation by using a biological materials testing machine and investigated the tensile properties before and after knotting, relaxation property and friction property of three common sutures: silk, polyglactin 910 and polypropylene. Results show that the tensile property decreased after knotting. The tensile strength of polyglactin 910 and elongation of polypropylene were the largest. During the relaxation process, the sutures relaxed the most in the first 2 hours. The relaxation from less to more was: polyglactin 910, silk and polypropylene. Coating or monofilament could obviously reduce the surface roughness of sutures, and thus reduce the friction force of the suture-suture interface. The friction force of the suture-suture interface increased with the increasing load but did no change with the increasing velocity. The results can provide an important theoretical basis for the optimizations of suture design and knotting operation.
Femtosecond laser small incision lenticule extraction (SMILE) with different residual stromal thicknesses (RST) is set to investigate its effect on corneal biomechanical properties of rabbits in vivo. In this study, 24 healthy adult Japanese rabbits were randomly divided into group A and B. The RST of group A was set 30% of the corneal central thickness (CCT), and the RST of group B was 50% of the CCT. The thickness of the corneal cap in both groups was set one third of CCT. Corneal visualization Scheimpflug technology (Corvis ST) and Pentacam three-dimensional anterior segment analyzer were used to determine corneal biomechanical and morphological parameters before surgery, and 1 week, 1 month and 3 months after surgery. Pearson correlation analysis was used to analyze factors affecting corneal biomechanical parameters after SMILE. The results showed that the corneal stiffness of group A was significantly higher than that of group B at 1 week and 1 month after surgery, and most biomechanical parameters returned to preoperative levels at 3 months postoperatively. The results of correlation analysis showed that postoperative CCT and RST were the main factors affecting corneal biomechanical parameters after SMILE. There was no significant difference in corneal posterior surface height (PE) between 3 months after surgery and before surgery in both two groups. It indicates that although the ability to resist deformation of cornea decreases in SMILE with thicker corneal cap and less RST, there is no tendency to keratoconus, which may be related to the preservation of more anterior stromal layer.