AIM:To observe the therapeutic efficacy of 25G+minimally invasive vitrectomy for retinal arterial macroaneurysm.METHODS:Totally 40 patients(40 eyes)who admitted to Jinan Mingshui Eye Hospital from January 2021 to May 2024 and with vitreous hemorrhage or dense premacular hemorrhage in the macular area caused by retinal arterial macroaneurysm, underwent 25G+minimally invasive vitrectomy. Preoperative and postoperative best-corrected visual acuity(BCVA), complications, and special cases were analyzed.RESULTS: The general patient data aligned with previous literature reports. The postoperative BCVA was significantly improved(t=9.72, P<0.01), and no significant serious surgical complications were observed. Notably, intraoperative findings revealed secondary macular holes in 3 eyes, resulting in poor visual prognosis.CONCLUSION: For vitreous hemorrhage or dense premacular hemorrhage caused by retinal arterial macroaneurysm, 25G+ minimally invasive vitrectomy is a safe and effective treatment. Visual prognosis was excluded for secondary macular holes.

Objective:To propose a method to measure the femoral anteversion angle based on the three-dimensional model of femur.Methods:From January 2019 to December 2023, a total of 50 patients (100 femurs) with patellar instability who underwent full-length CT examination of both lower limbs in Tianjin Hospital were retrospectively analyzed, including 16 males and 34 females, aged 28.5±11.9 years (range, 16-57 years). All patients underwent CT examination of both lower limbs, and the imaging data were imported into Mimics 21.0 software as DICOM format files. The femur was extracted by the threshold segmentation function, and the 3D model of the femur was reconstructed by appropriate trimming and smoothing. Three-dimensional models of the femur from 30 patients (60 femurs) were selected and imported into 3-matic 13.0 software for labeling of anatomical points and drawing of axes. The angle between the axis of the distal femur and the axis of the proximal femur was the femoral anteversion angle. Two observers positioned the spatial coordinates of the intercondylar fossa apex, the greater trochanter apex, the center of the femoral head, the femoral through-condylar axis and the posterior condylar tangent marker points on a 3D model of the femur to compare the differences between the groups. The femoral anteversion angles measured by different three-dimensional measurement methods were compared with the clinically reported femoral anteversion angles.Results:The difference between the femoral head center and intercondylar fossa apex coordinate data of 30 patients (60 femurs) measured by the two observers was not statistically significant ( P>0.05), whereas the data for the Y-axis coordinate of the greater trochanter apex were 25.77±23.21 and 22.08±25.73, respectively, and the difference was statistically significant ( t=2.906, P=0.017). The difference between the data of femoral through condylar and posterior condylar tangential coordinates of 30 patients (60 femurs) measured by the two observers was not statistically significant ( P>0.05). Using the femoral mechanical axis as the projection direction, the angle between the transcondylar axis and the posterior condylar tangent line was 5.97°±2.02° (range, 1.48°-12.08°). The anterior tilt of the femur measured by the two observers in the femoral neck cylinder fitting method was 23.35°±7.45° and 24.94°±9.01°, respectively, and the difference was statistically significant ( t=-2.147, P=0.040). The anterior inclination of the femur measured by the two observers in the femoral head ball enlargement method was 24.63°±7.66° and 25.12°±8.84°, the difference was not statistically significant ( t=-0.820, P=0.419). Using the femoral head ball expansion method to locate the proximal femoral axis, two observers measured the anterior tilt angle of the femur in 50 patients (100 femurs) according to the method described above, which was 23.30°±9.41° and 23.57°±9.97°, respectively, without a statistically significant difference ( t=-0.664, P=0.508), both smaller than the 29.56°±8.74° measured based on two-dimensional images in the imaging report, and the difference was statistically significant ( P<0.05). Conclusion:The femoral anteversion angle measured by the angle between the axis of the femoral condyle and the axis of the femoral neck based on the three-dimensional model is accurate and effective, and the measured value is smaller than that based on the two-dimensional images in clinical practice.

Objective To observe the changes in the subfoveal choroidal thickness(SFCT)of children and adoles-cents with different refractive states using optical coherence tomography angiography.Methods A total of 171 children and adolescents were followed.They were divided into the lower primary school group(6-8 years old),upper primary school group(9-11 years old),and junior high school group(12-14 years old)according to their age at the time of en-rollment.Dioptric examinations(including best corrected visual acuity,diopter,intraocular pressure,corneal curvature,axial length and SFCT)were performed,data collection was conducted twice in half a year(initial examination and review after half a year),and the eyeball parameters and changes in eyeball parameters after half a year among all groups were compared.Results The axial length and SFCT of subjects had significant differences among all groups(both P＜0.05).In children and adolescents,the axial length gradually lengthened and SFCT gradually thickened with age,while intraocular pressure and corneal curvature were not associated with age(both P＞0.05).In the initial examination and review after half a year,there was no significant difference in intraocular pressure,corneal curvature and SFCT of subjects with differ-ent refractive states in all groups(all P＞0.05),while the axial length of myopic subjects was greater than that of non-my-opic subjects in all groups(all P＜0.05).In the review after half a year,the SFCT of non-myopic subjects in the lower pri-mary school group and upper primary school group was significantly thickened(P＜0.001,P=0.003),while there was no significant difference in SFCT of myopic subjects in all groups compared with the value half a year ago(all P＞0.05).The axial length of all subjects showed a positive correlation with the SFCT in the initial examination and review after half a year(r=0.354,0.228,P＜0.05).Conclusion Myopia affects the increase in SFCT in children and adolescents.

Objective:To explore the optimal index of rotational displacement of femoral neck fractures by modeling the axial rotational displacement of femoral neck fractures after reduction and based on X-ray projections.Methods:Six dry human femur specimens, comprising 2 males and 4 females, were utilized in the study. Design and manufacture a proximal femur ortholateral and oblique X-ray casting jigs and mounts. The femoral neck fracture was modeled on the femoral specimen, with Pauwells 30°, 50°, and 70° models (2 each) made according to Pauwells typing. The fractures were manually repositioned with residual anterior 20°, 40° and 60° axial rotational displacements. Each fracture model was projected at different angles (pedicled 40°, pedicled 20°, vertical 0°, cephalad 20°, and cephalad 40°), and the trabecular angle and Garden's alignment index of the model were measured to observe the imaging characteristics of the fracture line on the medial oblique and lateral oblique radiographs.Results:In the presence of a 20° and 40° anterior rotational displacement following reduction of a femoral neck fracture, the trabecular angle in the rotationally displaced group was not significantly different from that of the anatomically repositioned group in various projection positions. However, when a residual rotational displacement of 60° was present, the trabeculae appeared blurred at most projection angles in the Pauwells 30° and 50° models, failing to measure trabecular angles. In the Pauwells 70° fracture model, the trabecular angle in the rotational displacement group was significantly different from that in the anatomical reduction group. In anteroposterior radiographs, when the anterior rotation displacement was 60° in the Pauwells 70° group, Garden's contralateral index showed an unsatisfactory restoration (150°, 142°), whereas all rotationally displaced models in the Pauwells 30° and Pauwells 50° groups had a Garden's contralateral index of >155°, which achieved an acceptable restoration. In lateral radiographs, all rotational displacement models with Garden's alignment index>180° failed to achieve acceptable repositioning, and the larger the Pauwells angle the greater the Garden's alignment index at the same rotational displacement. In the internal oblique position with a bias towards the foot side, the image showed partial overlap between the femoral head and the shaft, making it difficult to assess the quality of the reduction. Conversely, when projected cephalad, the femoral neck appeared longer, particularly at a projection angle of 40° cephalad, allowing for clear observation of the fracture line and the anatomy of the proximal femur. The trabeculae were not well visualized in the external oblique position.Conclusion:There are limitations in applying the trabecular angle to assess the axial rotational displacement of the femoral head after reduction of femoral neck fractures. The Pauwells 70° with residual rotational anterior displacement of 60° was the only way to detect axial rotational displacement of the femoral head on anteroposterior radiographs Garden's alignment index. For the determination of axial rotational displacement of the femoral head, the Garden's alignment index on lateral radiographs provides higher reliability.

Examining mechanisms involved in the mutual regulation between the muscular system and the skeletal system, elucidating the key issues responsible for loss of muscle and bone mass and strength, and thus halting the progression of these conditions are critical measures for reducing fractures caused by falls and subsequent disability and mortality.At present, most studies have treated the muscular system and the skeletal system separately, often ignoring the mutual regulation and connections between them.This article reviews the current research progress on the mechanisms of interaction between the two systems, aiming to provide a basis for the prevention, diagnosis and treatment of disuse-related diseases in the elderly population.

Objective To analyze the influence from material and size of the filling block on stress distributions of the tibial osteotomy model. Methods The filling blocks with three different materials (iliac bone, cancellous bone and polyetheretherketone (PEEK)) and five different sizes were established and implanted to the tibial osteotomy models, respectively. The mechanical loads were applied on the model, the stress distribution and edge displacement of the model were analyzed. Results For three kinds of materials, the stress at proximal end of the tibia and the plate, as well as edge displacement in the model implanted with filling block by iliac bone material were lower than those of the cancellous bone and PEEK, but the filling block by iliac bone material had the highest stress. When the filling blocks with different sizes were implanted in osteotomy space, the stress distribution on each part of the tibial osteotomy and edge displacement were different. Especially when the width of the filling block was reduced from 30 mm to 10 mm, the peak stress of the proximal tibia, steel plate and filling block was increased by 49. 3% , 92. 7% and 54. 4% on average. Conclusions Different filling block parameters will affect the stress distribution in different parts of the tibial osteotomy. The research results provide the theoretical basis for parameter selection of the tibial osteotomy filling block in clinic.

Objective To compare the differences in kinematic parameters and plantar pressures for two types of knee varus with tibial and femoral origins in gait analysis, so as to provide biomechanical theoretical basis for different types of genu varus. Methods Twenty-six patients with unilateral knee osteoarthritis (KOA) varus genu were enrolled, with 13 from femoral and 13 from tibial sources. Using Noraxon MyoMotion three-dimensional (3D) motion capture system and Footscan plantar pressure test system, the gait of the subjects during natural walking was measured, the temporal and spatial parameters of the gait, the kinematics parameters of lower limb joints and plantar pressures were collected, to make comparative analysis between the two groups. Results The range of knee flexion and extension of tibial varus, the peak of hip abduction, the range of motion (ROM) of hip adduction and abduction and the peak of ankle pronation were larger than those of femoral lateral genu varus. The peak of knee flexion and hip adduction was smaller than that of femoral lateral genu varus. Compared with femoral varus, subjects with tibial varus had increased stress time and peak pressure on the plantar of the 4th and 5th metatarsals (P<0.05). In the 3rd metatarsal region, the impulse of healthy femoral limb was greater than that of healthy limb with tibial deformity. While in the medial calcaneal region, the impulse of healthy femoral limb was smaller (P<0.05). Conclusions There are some differences in kinematic parameters and plantar pressures between two different types of unilateral genu varus patients. The results of this study are helpful to understand the abnormal gait caused by genu varus, and provide reliable reference for postoperative rehabilitation and limb exercise for different types of genu varus.

The sources of common knee valgus deformities were classified in order to better plan the orthopedic methods, matching prostheses and soft tissue repair of knee valgus deformities.Based on the analysis of typical clinical cases and the operability of classification standards in practical clinical practice, it is of great significance to establish a reasonable morphological classification of knee valgus deformity, in order to grasp the characteristics and patterns of the onset of valgus deformity. According to the origin of the deformity and the tension of the medial and lateral collateral ligaments, the classification of the genu valgus deformity can be divided into the classification of the traditional Genu valgum deformity origin and the classification of the new Genu valgum deformity origin. Although both of them highlight the skeletal characteristics and soft tissue conditions of the valgus deformity, they are quite different. Traditional classification is based on femoral tibial angle, valgus angle, etc; The new classification is divided into mechanical angle, anatomical angle, distal condylar angle, etc. The origin of Genu valgum deformity is generally complex. The traditional classification cannot fully reflect the origin of valgus deformity and the tension state of soft tissue. The new classification, especially based on the classification of anatomical angle valgus deformity, can not only reflect the morphological and anatomical details of knee valgus deformity, but also reflect the tension state of the medial and lateral collateral ligaments and local soft tissue stress state that determine the stability of the knee joint. At present, the commonly used surgical methods for valgus deformity of the knee include periarticular osteotomy of the knee and total knee Joint replacement. The former focuses on correcting extraarticular deformity without over repairing ligaments, and the latter focuses on force line correction, which is the final treatment for terminal valgus deformity. The application of digital technology in clinical orthopedics can improve the accuracy of implant placement. Implant placement needs to be based on the patient's bone characteristics and degree of deformity. For patients with severe deformity, the application of digital technology can improve the accuracy of implant placement and assist in the treatment of knee valgus deformity.

Objective:To observe the effects of continuous light exposure on skeletal muscle fiber type transformation and lipid metabolism, and to explore its internal relationship.Methods:Mice were randomly divided into normal light group and 24-hour continuous light group by random number table. The serum and skeletal muscle lipid content and urine 6-sulfatoxymelatonin(6-SML)level were detected by ELISA. The expression of circadian clock and lipid metabolism related genes mRNA were observed by realtime PCR. The muscle fiber type and lipid deposition were evaluated by tissue immunofluorescence as well as oil red O staining.Results:Compared with the normal light group, the level of 6-SML in urine at night decreased( P<0.05), and the expression level and rhythm of brain and muscle ARNT-like protein 1(Bmal1), circadian locomotor output cycles protein kaput(Clock), and period 2(Per2)mRNA in the skeletal muscle changed in continuous light group. In addition, the body weight, blood lipid, free fatty acid, and triglyceride contents of skeletal muscle in continuous light group increased significantly( P<0.05 or P<0.01), the expression of carnitine palmitoyltransferase 1b (Cpt1b)mRNA, the key enzyme of fatty acid oxidation, decreased significantly( P<0.05), while the expression of stearoyl-CoA desaturase(Scd1)mRNA, a lipid synthesis related gene, increased significantly( P<0.01). Further immunofluorescence analysis showed that the proportion of slow muscle fibers decreased and that of fast muscle fibers increased in continuous light group(both P<0.05). Conclusion:The process of ectopic deposition of lipid in skeletal muscle in mice induced by continuous light exposure may be related to the remodeling of skeletal muscle fibers.

Objective To investigate biomechanical characteristics of femoral neck fracture with different reduction qualities. Methods Three cases of Sawbones artificial femoral models were selected, and two cases of Pauwel III femoral neck fracture were modeled. Three cannulated screws were inserted into the models in the form of inverted triangle to fix the fracture. Two cases maintained different reduction qualities (defined as Model 1 and Model 2). In the 3 third case, no modeling operation was performed (defined as intact model). Then the strain gauges were respectively pasted on regions of interest of the 3 femoral models. Finally, the femur model was applied with the vertical load on mechanical testing machine. Results When the displacement of femoral head reached 4 mm, the average load of intact model, Model 1 and Model 2 was (236.30±5.35), (196.57±3.56), (69.50±2.95) N, showing significant differences. When the displacement of femoral head reached 5 mm, the average load of intact model, Model 1 and Model 2 was (276.7±3.40)，(232.93±2.64)，(80.83±4.54) N, showing significant differences. Conclusions The lower the reduction quality of the femoral neck fracture, the weaker the ability of the femur to bear stress, the higher the probability of nonunion, re-fracture and femoral head necrosis in the process of postoperative rehabilitation.