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28 September 2026, Volume 30 Issue 27 Previous Issue    Next Issue

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Finite element analysis of effects of opening wedge high tibial osteotomy on knee joint and internal fixation stress Chen Ping, Lu Hongxu, Xilinbaoleri 2026, 30 (27):  6969-6977.  doi: 10.12307/2026.446 Abstract ( 19 )   PDF (35606KB) ( 8 )   Save BACKGROUND: Opening wedge high tibial osteotomy is a well-established method for treating medial compartment knee osteoarthritis with varus deformity. There is still controversy over where the lower limb force correction should be placed after opening wedge high tibial osteotomy. OBJECTIVE: To investigate the mechanical characteristics of the knee joint and the internal fixation device after opening wedge high tibial osteotomy for knee osteoarthritis with varus deformity by finite element analysis of the mechanical loading of different force line patterns on the structures of the knee joint. METHODS: A 57-year-old female volunteer weighing 60 kg, diagnosed with left knee osteoarthritis, was selected. Multislice spiral CT scanning was performed on the left knee joint to obtain imaging data. Finite element analysis software was used for mechanical loading to obtain analysis results. The hinge point of the opening wedge high tibial osteotomy was set approximately 15 mm above the tibial plateau at the fibular head, with a 5 mm lateral tibial cortex preserved at the hinge. The medial cortex osteotomy was positioned 30 mm from the medial tibial plateau and expanded by 5 mm, 10 mm, and 15 mm, respectively. Load lines were set vertically at 25%, 50%, 62.5%, and 75% of the tibial plateau. An 8-hole Tomofix plate with a thickness of 2 mm and eight screws (diameter 4 mm; lengths: 60 mm/60 mm/55 mm/50 mm/38 mm/34 mm/32 mm/20 mm) was placed. The osteotomy gap was filled with cancellous bone. Stress and displacement diagrams for various parts of the knee joint three-dimensional model were obtained.  RESULTS AND CONCLUSION: (1) Before opening wedge high tibial osteotomy, knee joint stress was primarily concentrated on the lateral femoral condyle and medial tibial plateau, areas prone to cartilage wear. Meniscal stress was concentrated on the medial meniscus body and the anterior horn of the lateral meniscus. As the load-bearing region shifted outward, stress on the lateral cartilage and meniscus increased, while medial stress decreased. (2) In the 5 mm osteotomy model post-opening wedge high tibial osteotomy, as the stress loading position moved laterally, stress on the lateral cartilage and meniscus of the femur and tibia gradually increased. Stress on the graft bone was minimal at the 50% load position, and stress on the titanium plate and screws decreased with lateral movement of the load line. (3) Analysis of different expansion heights showed that with increased expansion, stress on the lateral cartilage and meniscus increased, and stress concentration on the titanium plate intensified, while screw stress changes were insignificant. (4) Fatigue fracture of the Tomofix titanium plate and screw breakage at the screw head were prone to occur at the posterior-medial aspect of the plate and at the D and 1 holes. (5) It is concluded that opening wedge high tibial osteotomy can effectively transfer the pressure in the medial compartment of the knee joint, but attention should be paid to the risk of increased stress in the lateral cartilage and meniscus. The posterior medial side of the Tomofix titanium plate and the screws at holes D and 1 are weak areas of stress concentration. During the operation, excessive correction should be avoided and the internal fixation design should be optimized to reduce the risk of complications. Figures and Tables | References | Related Articles | Metrics

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Force analysis of three-dimensional finite element models for single radius and multi radius prostheses during flexion and extension in total knee arthroplasty Chen Dongxu, Huang Dachao, Hu Yang, Li Zhaoxu 2026, 30 (27):  6978-6984.  doi: 10.12307/2026.836 Abstract ( 17 )   PDF (2015KB) ( 16 )   Save BACKGROUND: For patients with end-stage knee osteoarthritis, total knee arthroplasty is often necessary in clinical practice to address issues such as pain and limited mobility. Although knee replacement surgery has achieved good clinical results in treating severe osteoarthritis, there is still controversy over the clinical efficacy of single radius and multi radius prostheses. OBJECTIVE: To compare the stress characteristics of single radius and multi radius prostheses at different flexion angles in total knee arthroplasty using finite element analysis, and provide a basis for clinical selection.  METHODS: Based on normal adult CT data, a three-dimensional skeletal model was established and optimized using Mimics, Geomagic, and SolidWorks. Single radius and multi radius prostheses were assembled, and the 0°-120° flexion state was simulated in Ansys. The peak von Mises stress was used as the observation index to observe the Mises stress distribution and contact area on the tibial prosthesis pad, and to explore the biomechanical behavior changes of the knee joint after total knee arthroplasty.   RESULTS AND CONCLUSION: (1) With the increase of knee flexion angle from 0° to 90°, the contact stress of the tibial pad of both SR and MR prostheses increased with the increase of knee flexion angle. At high flexion angles of 90°to 120°, the stress of the multi radius prosthesis gradually decreased, while the stress of the single radius prosthesis slightly increased. (2) At 0° flexion, the joint capsule stress after single radius prosthesis was lower than that of multi radius prosthesis. (3) The contact area at low and medium flexion angles between 0° and 90° gradually decreased with increasing flexion angle, and the contact area on a single radius polyethylene pad was always greater than that on a multi radius polyethylene pad. (4) These findings indicate that both single radius and multi radius knee joint prostheses can meet clinical needs well. In clinical practice, the appropriate prosthesis should be selected according to the patient's age, activity level, and functional requirements.  Figures and Tables | References | Related Articles | Metrics

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Finite element analysis of biomechanical performance of a novel double-screw technique in lumbar revision of the original fixed segment Zhang Le, Julaiti·Maitirouzi, Xie Xuechen, Li Chunchao, Wang Yixi, Parhat·Rexiti 2026, 30 (27):  6985-6994.  doi: 10.12307/2026.862 Abstract ( 12 )   PDF (8358KB) ( 6 )   Save BACKGROUND: Currently, in clinical practice, the original internal fixation devices are often removed to perform revision surgery for failed vertebral fixation, which poses certain drawbacks and risks. The pedicle double-screw technique can preserve the original internal fixation devices, while the modified cortical bone trajectory technique offers excellent mechanical performance. Combining these two techniques for revision surgery can mitigate the conventional risks, although the mechanical performance of this new modified cortical bone trajectory technique in revision surgery is not yet well understood.  OBJECTIVE: To evaluate the mechanical performance of the cortical bone trajectory and modified cortical bone trajectory techniques in combined fixation during lumbar revision surgery using finite element analysis, and to explore the advantages of modified cortical bone trajectory over cortical bone trajectory in revision surgery.   METHODS: A three-dimensional model of the L1 to L5 vertebrae and intervertebral discs was created based on computed tomography scan data. In this model, screws were placed using the traditional trajectory pedicle screw technique. The traditional trajectory initial group and loosening group were distinguished based on the contact form of the screw-bone surface. Modified cortical bone trajectory and cortical bone trajectory screws were used to perform revision screw placement on the loosening group of the traditional trajectory, re-fixing the lumbar spine. Finite element analysis was employed to assess the mechanical performance of modified cortical bone trajectory and cortical bone trajectory in revision surgery.   RESULTS AND CONCLUSION: (1) Under flexion, extension, lateral bending, and axial rotation conditions, the range of motion of the cortical bone trajectory revision group decreased by 31.97%, 29.15%, 15.12%, and 29.63% compared with the control group, respectively. The stress on the fixed segment intervertebral discs decreased by 15.44%, 78.67%, 54.36%, and 40.55%. (2) The modified cortical bone trajectory revision group showed a decrease in range of motion by 32.16%, 29.33%, 15.47%, and 31.42%, and the stress on the fixed segment intervertebral discs decreased by 16.25%, 83.00%, 64.82%, and 45.83%. (3) Compared with cortical bone trajectory, the modified cortical bone trajectory revision group showed a decrease in range of motion by 0.28%, 0.25%, 0.40%, and 2.54%, and the stress on the fixed segment intervertebral discs decreased by 0.96%, 20.25%, 22.91%, and 8.88%. Additionally, the stress on the fixed segment vertebral bodies decreased by 15.78%, 4.75%, 11.22%, and 7.42%, and the stress on the internal fixation system decreased by 0.15%, 9.80%, 1.04%, and 0.84%. (4) Both cortical bone trajectory and modified cortical bone trajectory techniques effectively enhance the mechanical stability of the fixed segment in lumbar revision surgery, with modified cortical bone trajectory offering superior overall performance, providing a new technical option for clinical revision.  Figures and Tables | References | Related Articles | Metrics

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Finite element analysis of four Kirschner wire fixation methods for treating patellar transverse fractures Li Yongwei, Ye Hong 2026, 30 (27):  6995-7001.  doi: 10.12307/2026.368 Abstract ( 10 )   PDF (3242KB) ( 3 )   Save BACKGROUND: Kirschner wire and tension band internal fixation is the preferred surgical procedure for treating transverse patellar fractures, but it is often associated with postoperative instability, nonunion, and internal fixation failure. Therefore, optimizing the internal fixation method is of great clinical significance. OBJECTIVE: To investigate the effect of crossed Kirschner wire placement on the fixation of transverse patellar fractures.  METHODS: A patellar model was constructed using normal lower limb CT scan data. A transverse patellar fracture and Kirschner wire model was further constructed. Parallel, 30°, 45°, and 60° crossed Kirschner wire placement models were designed. Finite element analysis was performed to analyze the fracture surface stress, fracture surface displacement, Kirschner wire stress, and wire stress under five different working conditions (neutral knee position, 5° flexion, 15° flexion, 45° flexion, and 60° flexion). RESULTS AND CONCLUSION: The fracture surface stresses in the four internal fixation models ranged from 2.06 to 40.00 MPa. The parallel Kirschner wire fixation group had the highest fracture surface stress among all five conditions. The crossed 30° Kirschner wire fixation group had lower fracture surface stress at 15° of knee flexion than the crossed 45° and crossed 60° Kirschner wire fixation groups. The fracture surface displacements in the four internal fixation models ranged from 0.03 to 0.61 mm. The crossed 60° Kirschner wire fixation group had the highest fracture surface displacement at 5° and 15° of knee flexion, the parallel Kirschner wire fixation group had the lowest fracture surface displacement at 5° of knee flexion, and the crossed 30° Kirschner wire fixation group had the lowest fracture surface displacement at 15° of knee flexion. The wire stresses in the four internal fixation models ranged from 56.80 to 2 511.00 MPa. The parallel K-wire fixation group had the highest wire stress at 5° and 15° of knee flexion, and the crossed 30° Kirschner wire fixation group had the lowest wire stress at 5° and 15° of knee flexion. The Kirschner wire stresses in the four internal fixation models ranged from 65.67 to 1 018.00 MPa. The Kirschner wire stress in the 60° crossed Kirschner wire fixation group was highest at 5° of knee flexion, the parallel Kirschner wire fixation group at 15° of knee flexion, and the 30° crossed Kirschner wire fixation group at both 5° and 15° of knee flexion. The results showed that the 30° crossed Kirschner wire placement performed best in terms of fracture stability and stress distribution within the internal fixation system, demonstrating excellent biomechanical advantages.  Figures and Tables | References | Related Articles | Metrics

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Finite element analysis of five internal fixation strategies for Schatzker IV tibial plateau fractures Liu Mingxiang, Zhou Zulong, Fang Run, Kong Lingchao, Wu Chaofan, Wu Chaoqun, Zhang Chengnan, Ning Rende 2026, 30 (27):  7002-7008.  doi: 10.12307/2026.799 Abstract ( 13 )   PDF (2638KB) ( 6 )   Save BACKGROUND: Schatzker IV tibial plateau fractures are highly challenging due to their involvement of the primary weight-bearing area and high rate of soft tissue complications. Although traditional double plating provides mechanical stability, it violates the minimally invasive principle and is associated with more postoperative complications, especially in elderly patients or those with high-energy trauma. Currently, there is a lack of an internal fixation strategy that can meet both mechanical stability and minimally invasive requirements. OBJECTIVE: To establish a three-dimensional model of Schatzker IV tibial plateau fractures using the finite element method and compare the biomechanical stability of five fixation methods to provide an optimal surgical option for the treatment of Schatzker IV tibial plateau fractures. METHODS: A healthy male volunteer underwent knee CT scanning, and a Schatzker IV tibial plateau fracture model was constructed using finite-element software. Five internal-fixation configurations were defined as Groups A, B, C, D, and E. Group A: isolated medial plate; Group B: medial plate plus two posteromedial tension screws; Group C: medial plate plus two lateral tension screws; Group D: posteromedial double plating; Group E: medial-lateral double plating. Under identical boundary and constraint conditions, finite-element analysis software was employed to evaluate the biomechanical performance of five internal fixation models. RESULTS AND CONCLUSION: (1) The finite element analysis results showed that the minimally invasive combinations (Groups B and C) had comparable overall biomechanical performance to traditional double plating. (2) Group B is an ideal choice for elderly patients because it has the lowest fracture fragment stress (9.039 2 MPa), which can effectively prevent osteoporosis-related collapse, and the percutaneous screw technique reduces the risk of soft tissue complications. (3) Group C has potential for application in young patients, thanks to its minimal implant displacement (4.388 mm), providing excellent stability, and the lateral tension screws avoid vascular and nerve injuries associated with the posteromedial approach. Figures and Tables | References | Related Articles | Metrics

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Finite element analysis of two fixation methods for Salter-Harris type II distal radius epiphyseal fracture in children Zhou Yunfan, Meng Xiangqi, Shen Chenxiao 2026, 30 (27):  7009-7014.  doi: 10.12307/2026.222 Abstract ( 11 )   PDF (42421KB) ( 3 )   Save BACKGROUND: There is controversy over the selection of treatment options for pediatric distal radius epiphyseal fractures, and there is a lack of theory in biomechanical performance between Kirschner wire internal fixation and splint external fixation in terms of stability. OBJECTIVE: To explore the biomechanical characteristics of external fixation with splints and internal fixation with Kirschner wires in the treatment of Salter-Harris type II distal radial epiphyseal fractures in children through finite element experiments. METHODS: Based on CT data of children's wrist joint, Salter-Harris type II distal radius epiphyseal fracture was simulated, and model A was established. On this basis, two different fixation methods were established: model B, Kirschner wire cross internal fixation (2 Kirschner wires); Model C, externally fixed with 4 clamps. Loads were applied to the model to simulate the displacement and stress distribution of the distal fracture end and the distal radioulnar joint of the wrist joint under axial pressure combined with pronation and supination conditions. RESULTS AND CONCLUSION: (1) Model A has the highest displacement peak area and stress peak displacement degree in the vertical pressure combined pre rotation and post rotation motion states. The maximum stress and relative displacement values between the distal radius fracture end and the distal radioulnar joint are the highest. (2) Compared with Model C, Model B has a smaller maximum stress and displacement value, and the peak area of the displacement cloud map has also decreased. The peak area of the stress cloud map has shifted back towards the center. There is no significant difference in the percentage difference in the maximum stress and displacement values between Models B and C and Model A, indicating that the two fixing methods have similar effects on alleviating relative displacement and structural stress. (3) The results showed that Kirschner wire internal fixation and splint external fixation can effectively maintain the stability of the distal fracture end and the distal radioulnar joint. The splint, as an external fixation device and Kirschner wire internal fixation, showed similar fixation effects on Salter-Harris type II distal radial epiphyseal fractures. Figures and Tables | References | Related Articles | Metrics

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Biomechanical finite element analysis of different ulnar shortening osteotomy techniques in treatment of ulnar impaction syndrome Zhang Shuai, Han Shichong, Zeng Wenchao 2026, 30 (27):  7015-7022.  doi: 10.12307/2026.860 Abstract ( 6 )   PDF (3339KB) ( 2 )   Save BACKGROUND: Ulnar impaction syndrome is a common wrist disorder, and ulnar shortening osteotomy is one of the definitive surgical interventions for its treatment. Although various ulnar shortening osteotomy techniques exist, numerous clinical comparative studies have focused on pairwise comparisons, while biomechanical simulations comparing the efficacy of different osteotomy methods via finite element analysis remain unreported.  OBJECTIVE: To simulate and compare the biomechanical characteristics of ulnar impaction syndrome under different osteotomy treatment modalities employing finite element method so as to provide references and evidence for clinical decision-making. METHODS: CT data of the intact ulna and radius from a healthy adult male volunteer were utilized. Modeling and finite element software platforms — Mimics 19.0, Geomagic Studio 2013, SolidWorks 2019, and Ansys 17.0 — were sequentially applied to construct five ulnar osteotomy models: (1) distal ulnar V-shaped osteotomy; (2) distal ulnar transverse osteotomy; (3) ulnar metaphysis transverse osteotomy; (4) distal ulnar trapezoidal osteotomy; (5) distal ulnar oblique osteotomy. Following experimental design and internal fixation principles, plates and screws were assembled. Three simulated wrist motion states (axial compression, pronation, and supination) were applied to each model with corresponding constraints and loads. Stress and displacement nephograms, along with quantitative data at the osteotomy sites and fixation devices, were analyzed and compared against experimental benchmarks to draw relevant conclusions. RESULTS AND CONCLUSION: (1) Under three different motion patterns (different loads), all five ulnar shortening osteotomy models demonstrated comparable stability at the osteotomy sites, with no significant relative differences. (2) Variations in stress deformation of internal fixation devices among the five different ulnar shortening osteotomy methods were observed across three simulated motions: Transverse metaphyseal osteotomy fixation plates exhibited fracture risks during pronation and deformation risks during supination. (3) The V-shaped distal ulnar osteotomy fixation demonstrated superior stability in stress distribution and displacement across all three simulated conditions. Figures and Tables | References | Related Articles | Metrics

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Correlation between lower limb biomechanics during single-leg landing and hip joint muscle strength in patients with anterior cruciate ligament reconstruction Yang Zimeng, Zheng Hongrong, Yu Hao, Gao Peng, Sun Lezhong, Sheng Xiangmei 2026, 30 (27):  7023-7029.  doi: 10.12307/2026.839 Abstract ( 9 )   PDF (1861KB) ( 5 )   Save BACKGROUND: Recovery of knee joint function and muscle strength is a key focus of rehabilitation after anterior cruciate ligament reconstruction. However, abnormal inter-joint mechanical patterns of the lower limbs may alter lower limb biomechanics during movement and increase the risk of anterior cruciate ligament injury.  OBJECTIVE: To explore the lower limb biomechanical characteristics of anterior cruciate ligament reconstruction patients during single-leg landing 2 years after surgery, and their correlation with hip joint muscle strength.  METHODS: Totally 23 subjects who underwent anterior cruciate ligament reconstruction were randomly recruited. The Qualisys three-dimensional motion capture system and AMTI three-dimensional force platforms were used to capture kinematic and kinetic data of both lower limbs during single-leg landing. The Biodex isokinetic muscle testing system was used to measure muscle strength of both hip and knee joints at an angular velocity of 60°/s. Paired sample t-tests were used to compare the biomechanical characteristics of bilateral lower limb joints and the isokinetic muscle strength of the hip and knee joints at 60°/s. Pearson correlation analysis was employed to examine the correlation between kinetic data from the single-leg landing test and the isokinetic muscle strength of the hip and knee.  RESULTS AND CONCLUSION: (1) At the moment of single-leg landing, patients who had undergone anterior cruciate ligament reconstruction on the affected side showed smaller knee extension angles, smaller ranges of knee flexion/extension motion, smaller vertical ground reaction forces, smaller peak moments of hip extension, hip abduction, and knee extension, and larger hip extension angles and larger ranges of hip flexion/extension motion at the time of contact. (2) During angular movement at 60°/s, the muscle strength of the operated side for hip abduction, hip extension, knee flexion, and knee extension was significantly lower. (3) During single-leg landing, the peak vertical ground reaction force on the operated side was significantly related to the peak hip extension torque and hip abduction strength, while the peak knee extension torque on the operated side was significantly related to the strength of hip abduction, flexion, and extension. (4) The results showed that two years post-anterior cruciate ligament reconstruction, patients fail to regain equal strength on the operated side, possibly due to neural inhibition induced by surgery. To reduce vertical ground reaction force during single-leg landing, they use a hip-muscle-powered buffering strategy. Yet, the operated side's lower hip abduction torque peak also compromises coronal-plane knee stability. Therefore, it is recommended that after anterior cruciate ligament reconstruction, patients continue to do hip and knee strengthening exercises for 2 years, focusing on hip abduction, extension, and knee flexion and extension while specifically including neuromuscular training and sport-specific technique guidance. This will enhance neuromuscular control during movement and prevent negative impacts from faulty movement patterns. Figures and Tables | References | Related Articles | Metrics

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Correlation between sacro-femoro-pubic angle and spine-pelvic parameters in patients with Lenke types 1, 5, and 6 adolescent idiopathic scoliosis He Zhuoqun, Wang Haiyan, Li Xiaohe, Zhang Ruofan, Shi Guopeng, Bai Lili, Wang Xiaolu 2026, 30 (27):  7030-7036.  doi: 10.12307/2026.462 Abstract ( 8 )   PDF (2374KB) ( 3 )   Save BACKGROUND: The sacro-femoro-pubic angle, as a coronal plane alternative to the pelvic tilt angle, has an unclear association in different Lenke classifications of adolescent idiopathic scoliosis, limiting clinical application of the sacro-femoro-pubic angle in classification-specific assessment. OBJECTIVE: To explore the correlation between the sacro-femoro-pubic angle and spine-pelvic parameters (pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis, and main Cobb angle) in patients with Lenke types 1, 5, and 6 adolescent idiopathic scoliosis, and to establish classification-specific regression models.  METHODS: Clinical and imaging data of 191 adolescent idiopathic scoliosis patients were retrospectively analyzed, including 60 with Lenke type 1, 65 with Lenke type 5, and 66 with Lenke type 6. Pearson or Spearman correlation analysis was used to examine the correlations between left/right sacro-femoro-pubic angle and pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis, main Cobb angle, and sagittal vertical axis in each type. Parameters with statistical significance underwent univariate linear regression analysis to construct linear regression models. RESULTS AND CONCLUSION: (1) In Lenke type 1 adolescent idiopathic scoliosis patients, right sacro-femoro-pubic angle showed a significant negative correlation with pelvic tilt (r=-0.366, P=0.028) and a significant positive correlation with lumbar lordosis (r=0.429, P=0.007; r=0.460, P=0.007). In Lenke type 5 adolescent idiopathic scoliosis patients, left/right sacro-femoro-pubic angle showed a significant positive correlation with lumbar lordosis (r=0.415, P=0.007; r=0.400, P=0.007). In Lenke type 6 adolescent idiopathic scoliosis patients, while left/right sacro-femoro-pubic angle showed a significant negative correlation with pelvic tilt (r=-0.385, P=0.007; r=-0.376, P=0.014). Univariate regression models quantified these associations (R²=0.13-0.21). Among them, the regression slope between sacro-femoro-pubic angle and lumbar lordosis was largest (0.85-0.89) in Lenke type 5 adolescent idiopathic scoliosis patients, while the regression slope between sacro-femoro-pubic angle and pelvic tilt ranged from -0.52 to -0.54 in Lenke type 6 adolescent idiopathic scoliosis patients. (2) The results indicate that the association between sacro-femoro-pubic angle and spine-pelvic parameters in Lenke types 1, 5, and 6 adolescent idiopathic scoliosis patients exhibits clear classification-specificity. Lenke types 1 and 5 are primarily characterized by a positive association between sacro-femoro-pubic angle and lumbar lordosis, while Lenke type 6 is characterized by a bilateral negative association between sacro-femoro-pubic angle and pelvic tilt. Figures and Tables | References | Related Articles | Metrics

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Spinal-pelvic sagittal parameters and plantar pressure characteristics in elderly patients with degenerative lumbar spondylolisthesis Han Zijia, He Xiaochen, Wang Jiarong, Tian Yichao, Wang Lixin, Gong Shuhui 2026, 30 (27):  7037-7043.  doi: 10.12307/2026.866 Abstract ( 9 )   PDF (1933KB) ( 4 )   Save BACKGROUND: Degenerative lumbar spondylolisthesis is a common spinal degenerative disorder among older adults, often accompanied by spinopelvic sagittal imbalance. The characteristics of plantar pressure and balance function in these patients have not been fully elucidated. OBJECTIVE: To investigate the spinopelvic sagittal parameters and plantar pressure characteristics in older adults with degenerative lumbar spondylolisthesis, to provide a reference for early diagnosis and the development of rehabilitation plans in older adults with degenerative lumbar spondylolisthesis. METHODS: A total of 33 patients with degenerative lumbar spondylolisthesis (degenerative lumbar spondylolisthesis group) and 35 healthy older adults (control group) were enrolled. Lateral radiographs of the whole spine were obtained to measure spinopelvic sagittal parameters. Plantar pressure distribution, including the pressure ratio, peak pressure in eight regions of interest, and center of pressure trajectory parameters, was collected using a plantar pressure analysis system. The differences in spinal-pelvic sagittal parameters, center of pressure trajectory, and plantar pressure parameters between the two groups were compared and analyzed. RESULTS AND CONCLUSION: (1) Compared with the control group, the degenerative lumbar spondylolisthesis group showed significant increases in pelvic incidence, pelvic tilt, sacral slope, and lumbar lordosis (P < 0.05). (2) Compared with the control group, the degenerative lumbar spondylolisthesis group exhibited a significant increase in the pressure percentage under the left forefoot and the forefoot overall (P < 0.05), while the pressure percentage under the left hindfoot and the hindfoot overall decreased significantly (P < 0.05). (3) Compared with the control group, peak pressure under the left first metatarsal bone was significantly higher in the degenerative lumbar spondylolisthesis group (P < 0.05), whereas peak pressure under the right fifth metatarsal and the left medial arch was significantly lower (P < 0.05). (4) Compared with the control group, under eyes-open and eyes-closed conditions, the degenerative lumbar spondylolisthesis group demonstrated a significant increase in center of pressure trajectory length, 95% confidence ellipse area, and the average center of pressure displacement in the anteroposterior (X) and mediolateral (Y) directions (P < 0.05). (5) It is indicated that older adults with degenerative lumbar spondylolisthesis exhibit characteristic changes in spinopelvic sagittal alignment, notably increased pelvic incidence, pelvic tilt, sacral slope, and lumbar lordosis. Their plantar pressure distribution shifts anteriorly, with increased forefoot pressure and decreased hindfoot pressure, indicating an imbalance in foot mechanical symmetry and disruption of the normal tripod support structure. These alterations are accompanied by reduced center of pressure stability, reflecting impaired balance function in degenerative lumbar spondylolisthesis patients. Figures and Tables | References | Related Articles | Metrics

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Efficacy and biomechanical analysis of L-shaped plate treatment for osteoporotic Schatzker type II tibial plateau fractures Shi Gaolong, Hu Zhenghui, Ling Zhuoyan, Xie Zonggang 2026, 30 (27):  7044-7052.  doi: 10.12307/2026.299 Abstract ( 7 )   PDF (2422KB) ( 3 )   Save BACKGROUND: Schatzke type II fractures often involve the posterolateral plateau, resulting in weakened bone strength, increased fixation challenges, and increased risk of postoperative collapse. Optimizing treatment strategies to balance stability and minimize trauma is urgently needed. OBJECTIVE: To evaluate the clinical efficacy of simple lateral L-shaped plate fixation for osteoporotic Schatzker type II tibial plateau fractures involving the posterolateral aspect, and to compare its biomechanical properties with those of lateral L-shaped plate combined with posterior T-shaped plate fixation using finite element analysis. METHODS: A retrospective analysis was conducted on 39 patients with osteoporotic Schatzker type II tibial plateau fractures involving the posterolateral aspect treated between January 2018 and December 2023. Patients were divided into L-shaped plate group (simple lateral L-shaped plate fixation, n=24) and combined group (lateral L-shaped plate combined with posterior T-shaped plate fixation, n=15). Key indicators were compared, including operative time, intraoperative blood loss, bone mineral density, preoperative tibial plateau collapse, time from injury to surgery, postoperative radiographic parameters (tibial plateau varus angle and posterior tilt angle), knee range of motion, and Hospital for Special Surgery and Lysholm scores. Simultaneously, finite element models of Schatzker type II tibial plateau fracture were established based on CT data from a healthy adult male. Four groups were constructed: non-osteoporotic bone (Group A: simple L-shaped plate; Group B: L-shaped + T-shaped plate) and osteoporotic bone (Group C: simple L-shaped plate; Group D: L-shaped + T-shaped plate). Under axial loads of 250, 500, and 750 N, the overall displacement, tibial stress, and internal fixation stress of the models were analyzed in each group. RESULTS AND CONCLUSION: (1) Clinical trial results: The results showed no significant differences between the two groups in age, gender, body mass index, bone mineral density, preoperative tibial plateau collapse, or time from injury to surgery (P > 0.05). Operative time and intraoperative blood loss in L-shaped plate group were significantly lower than those in combined group (P < 0.000 1). Immediate postoperative tibial plateau varus angle and posterior tilt angle showed no significant differences between groups (P > 0.05). At the final follow-up, the varus angle in L-shaped plate group was smaller than in combined group (P=0.04), while the posterior tilt angle showed no significant difference (P > 0.05). At the final follow-up, no statistical differences were observed in knee range of motion, Hospital for Special Surgery scores, or Lysholm scores between groups (P > 0.05). (2) Finite element analysis results: Under the same loads, both non-osteoporotic and osteoporotic bone models with T-shaped plate-assisted fixation (Groups B/D) exhibited superior performance in terms of overall displacement and lower tibial stress compared with simple L-shaped plate fixation (Groups A/C). (3) These findings suggest that for osteoporotic Schatzker type II tibial plateau fractures involving the posterolateral aspect, simple lateral L-shaped plate fixation can achieve satisfactory reduction stability and functional recovery, with clinical outcomes comparable to dual-plate fixation. Finite element analysis indicates superior biomechanical performance with dual-plate fixation; however, considering the significantly reduced surgical trauma and favorable clinical outcomes with simple lateral L-shaped plate fixation, routine addition of a posterior T-shaped plate is not necessary. Figures and Tables | References | Related Articles | Metrics