1.Biomechanical study on wing shaped titanium plate fixation of acetabular anterior column and posterior hemi-transverse fracture under multiple working conditions.
Jianwu ZHANG ; WURIKAIXI AIYITI ; Gang LYU ; MAIMAIAILI YUSHAN ; Zhiqiang MA ; Chao MA
Journal of Biomedical Engineering 2025;42(2):351-358
This article aims to compare and analyze the biomechanical differences between wing-shaped titanium plates and traditional titanium plates in fixing acetabular anterior column and posterior hemi-transverse (ACPHT) fracture under multiple working conditions using the finite element method. Firstly, four sets of internal fixation models for acetabular ACPHT fractures were established, and the hip joint stress under standing, sitting, forward extension, and abduction conditions was calculated through analysis software. Then, the stress of screws and titanium plates, as well as the stress and displacement of the fracture end face, were analyzed. Research has found that when using wing-shaped titanium plates to fix acetabular ACPHT fractures, the peak stress of screws decreases under all working conditions, while the peak stress of wing-shaped titanium plates decreases under standing and sitting conditions and increases under forward and outward extension conditions. The relative displacement and mean stress of the fracture end face decrease under all working conditions, but the values are higher under forward and outward extension conditions. Wing-shaped titanium plates can reduce the probability of screw fatigue failure when fixing acetabular ACPHT fractures and can bear greater loads under forward and outward extension conditions, improving the mechanical stability of the pelvis. Moreover, the stress on the fracture end surface is more conducive to stimulating fracture healing and promoting bone tissue growth. However, premature forward and outward extension rehabilitation exercises should not be performed.
Titanium
;
Bone Plates
;
Humans
;
Acetabulum/surgery*
;
Fracture Fixation, Internal/methods*
;
Biomechanical Phenomena
;
Finite Element Analysis
;
Bone Screws
;
Fractures, Bone/surgery*
;
Stress, Mechanical
;
Working Conditions
2.Automatic measurement of acetabular cup anteversion angle using an accurate recognition technology based on improved Otsu algorithm and feature point.
Qian LIU ; Yunqing MA ; Bo WU ; Yao ZHANG ; Jingwen QI ; Yuqian MEI
Journal of Biomedical Engineering 2025;42(3):592-600
The orientation of the acetabular cup in hip joint anteroposterior radiograph is a key factor in evaluating the postoperative outcomes of total hip arthroplasty (THA). Currently, measurement of the acetabular cup anteversion angle primarily relies on manual drawing of auxiliary lines by orthopedic surgeons and calculations using scientific calculators. This study proposes an automated computer-aided measurement method for the acetabular cup anteversion angle based on hip joint anteroposterior radiograph. The proposed method segments hip prosthesis images using an improved Otsu algorithm, identifies feature points at the acetabular cup opening by combining circle-fitting theory and the cup's geometric characteristics, and fits an ellipse to the cup opening to calculate the anteversion angle. A total of 104 hip joint anteroposterior radiographs, including 71 right-sided and 81 left-sided prostheses, were analyzed. Two orthopedic surgeons independently measured the postoperative anteversion angles, and the results were compared with computer-generated measurements for correlation analysis. Spearman and Pearson correlation analyses demonstrated significant correlations between the proposed method and manual measurements for both the right group ( r = 0.795, P < 0.01) and the left group ( r = 0.859, P < 0.01). This method provides a reliable reference for orthopedic surgeons to assess postoperative prognosis.
Humans
;
Acetabulum/anatomy & histology*
;
Arthroplasty, Replacement, Hip/methods*
;
Algorithms
;
Hip Prosthesis
;
Hip Joint/diagnostic imaging*
;
Radiography
;
Image Processing, Computer-Assisted/methods*
3.Application of personalized three-dimensional printed customized prostheses in severe Paprosky type Ⅲ acetabular bone defects.
Shuailei LI ; Hao CHAI ; Yongqiang SUN
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(1):13-19
OBJECTIVE:
To analyze the short-term effectiveness and safety of personalized three-dimensional (3D) printed customized prostheses in severe Paprosky type Ⅲ acetabular bone defects.
METHODS:
A retrospective analysis was conducted on 8 patients with severe Paprosky type Ⅲ acetabular bone defects and met the selection criteria between January 2023 and June 2024. There were 3 males and 5 females, with an average age of 64.6 years ranged from 56 to 73 years. All primary replacement prostheses were non-cemented, including 1 ceramic-ceramic interface, 1 ceramic-polyethylene interface, and 6 metal-polyethylene interfaces. The time from the primary replacement to the revision was 4 days to 18 years. The reasons for revision were aseptic loosening in 5 cases, revision after exclusion in 2 cases, and repeated dislocation in 1 case. The preoperative Harris score was 39.5±3.7 and the visual analogue scale (VAS) score was 7.1±0.8. The operation time, intraoperative blood loss, hospital stay, and complications were recorded. The hip function was evaluated by Harris score, and the degree of pain was evaluated by VAS score. The acetabular cup abduction angle, anteversion angle, rotational center height, greater trochanter height, and femoral offset were measured on X-ray film.
RESULTS:
The operation time was 95-223 minutes, with an average of 151.13 minutes. The intraoperative blood loss was 600-3 500 mL, with an average of 1 250.00 mL. The hospital stay was 13-20 days, with an average of 16.88 days. All 8 patients were followed up 2-12 months, with an average of 6.4 months. One patient had poor wound healing after operation, which healed well after active symptomatic treatment. One patient had lower limb intermuscular vein thrombosis, but no thrombosis was found at last follow-up. No serious complications such as aseptic loosening, infection, dislocation, and periprosthetic fracture occurred during the follow-up. At last follow-up, the Harris score was 72.0±6.2 and the VAS score was 1.8±0.7, which were significantly different from those before operation ( t=-12.011, P<0.001; t=16.595, P<0.001). On the second day after operation, the acetabular cup abduction angle ranged from 40° to 49°, with an average of 44.18°, and the acetabular cup anteversion angle ranged from 19° to 26°, with an average of 21.36°, which were within the "Lewinneck safety zone". There was no significant difference in the rotational center height, greater trochanter height, and femoral offset between the healthy side and the affected side ( P>0.05).
CONCLUSION
The use of personalized 3D printed customized prostheses for the reconstruction of severe Paprosky type Ⅲ acetabular bone defects can alleviate pain and enhances hip joint function, and have good postoperative prosthesis position, without serious complications and have good safety.
Humans
;
Printing, Three-Dimensional
;
Male
;
Female
;
Middle Aged
;
Acetabulum/surgery*
;
Aged
;
Retrospective Studies
;
Hip Prosthesis
;
Prosthesis Design
;
Arthroplasty, Replacement, Hip/instrumentation*
;
Reoperation
;
Treatment Outcome
4.Relationship between knee meniscus and posterior tibial slope in healthy adults and patients with anteromedial osteoarthritis in Heilongjiang province.
Shuxin GUO ; Shikun GUAN ; Rui HUAN ; Ning LIU
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(1):32-39
OBJECTIVE:
To measure and analyze the relationships among the posterior tibial slope (PTS), meniscal slope (MS), and meniscus posterior horn thickness (MPHT) of the medial and lateral tibial plateau in healthy people and patients with anteromedial osteoarthritis (AMOA) in Heilongjiang province, so as to provide reference basis for appropriate tibial osteotomy and prosthesis placement angles in knee joint surgeries.
METHODS:
A retrospective collection of imaging data from knee joint MRI examinations conducted prior to AMOA for various reasons was performed. A total of 103 healthy individuals (healthy group) and 30 AMOA patients (AMOA group) were included. There was no significant difference in the gender composition ratio, side, and body mass index between the two groups ( P>0.05); however, the comparison of ages between the two groups showed a significant difference ( P<0.05). The collected DICOM format image data was imported into the RadiAnt DICOM Viewer software and measured the medial PTS (MPTS), lateral PTS (LPTS), medial MS (MMS), lateral MS (LMS), medial MPHT (MMPHT), and lateral MPHT (LMPHT) with standard methods. The differences of the above indexes between the two groups and between different genders and sides in the two groups were compared, and Pearson correlation analysis was carried out. At the same time, the measured data of healthy group were compared with the relevant literature reported in the past.
RESULTS:
Compared to the healthy group, the AMOA group exhibited significantly smaller MPTS and LPTS, as well as significantly greater MMPHT and LMPHT, with significant differences ( P<0.05). However, there was no significant difference in the MMS and LMS between the two groups ( P>0.05). The differences in various indicators between genders and sides within the two groups were not significant ( P>0.05). The correlation analysis and regression curves indicated that both MPTS and LPTS in the two groups were positively correlated with their respective ipsilateral MS and MPHT ( P<0.05); as PTS increased, the rate of increase in MS and MPHT tend to plateau. Compared to previous related studies, the MPTS and LPTS measured in healthy group were comparable to those of the Turkish population, exhibiting smaller values than those reported in other studies, while MMS and LMS were relatively larger, and MMPHT and LMPHT were smaller.
CONCLUSION
In healthy people and AMOA patients in Heilongjiang province, PTS has great individual differences, but there is no significant individual difference in MS. MPHT can play a certain role in retroversion compensation, and its thickness increase may be used as one of the indicators to predict the progression of AMOA. The above factors should be taken into account when UKA is performed, and the posterior tilt angle of tibial osteotomy should be set reasonably after preoperative examination and evaluation.
Humans
;
Osteoarthritis, Knee/surgery*
;
Retrospective Studies
;
Tibia/pathology*
;
Male
;
Female
;
Adult
;
Menisci, Tibial/anatomy & histology*
;
China
;
Knee Joint/pathology*
;
Magnetic Resonance Imaging
;
Middle Aged
;
Aged
;
Osteotomy
5.Posterior minimally invasive approach for treatment of posterior wall acetabular fractures.
Wenbo LI ; Lihong LIU ; Peisheng SHI ; Yun XUE ; Wei WANG ; Jie SHI ; Chuangbing LI ; Xianqing SHI ; Xiaowen DENG ; Qiuming GAO
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(2):134-139
OBJECTIVE:
To investigate the effectiveness of posterior minimally invasive approach in the treatment of posterior wall acetabular fractures.
METHODS:
The clinical data of 17 patients with posterior wall acetabular fractures treated with posterior minimally invasive approach between March 2019 and June 2023 were retrospectively analyzed. There were 14 males and 3 females with an average age of 41 years ranging from 28 to 57 years. The causes of injury were traffic accident in 12 cases and falling from height in 5 cases. There were 3 cases complicated with posterior hip dislocation and 2 cases complicated with sciatic nerve injury. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 11 cases of type A1.1 and 6 cases of type A1.2. The time from injury to operation was 5-8 days, with an average of 6.2 days. The incision length, intraoperative blood loss, and operation time were recorded. The quality of posterior wall fracture reduction were evaluated by Matta criteria, and hip function were evaluated by modified Merle d'Aubign-Postel score criteria at 6 months after operation and last follow-up.
RESULTS:
The operation was successfully completed in 17 cases. The length of incision ranged from 7 to 9 cm, with an average of 8.3 cm, and all incisions healed by first intention. The intraoperative blood loss ranged from 200 to 350 mL, with an average of 281 mL. The operation time ranged from 45 to 70 minutes, with an average of 57 minutes. Two patients had sciatic nerve injury before operation, and the sciatic nerve function recovered completely at 3 months after operation; the other 15 patients had no symptoms of sciatic nerve injury after operation. All the 17 patients were followed up 14-27 months, with an average of 19.5 months. At 1 week after operation, according to the Matta criteria, anatomical reduction was achieved in 12 cases and satisfactory reduction in 5 cases, with a satisfaction rate of 100%. According to the modified Merle d'Aubign-Postel scoring system, the hip function score was 13-18 (mean, 16.1) at 6 months after operation. Among them, 5 cases were excellent, 9 were good, and 3 were fair, with an excellent and good rate of 82.4%. At last follow-up, the hip function score was 7-18 (mean, 13.7), of which 3 cases were excellent, 9 were good, 3 were fair, and 2 were poor, with an excellent and good rate of 70.6%. During the follow-up, there was no infection, failure of internal fixation, and femoral head necrosis, and heterotopic ossification occurred in 2 cases.
CONCLUSION
The posterior minimally invasive approach has the advantages of less trauma, shorter operation time, less blood loss, without cutting off the external rotator muscle. Exposure through the gluteus medius-piriformis space and piriformis-supercilium space can provide sufficient safe exposure for the posterior wall acetabulum fracture, which is a reliable alternative approach for the posterior acetabular fracture.
Humans
;
Acetabulum/surgery*
;
Male
;
Female
;
Adult
;
Middle Aged
;
Minimally Invasive Surgical Procedures/methods*
;
Retrospective Studies
;
Fracture Fixation, Internal/instrumentation*
;
Fractures, Bone/diagnostic imaging*
;
Treatment Outcome
;
Operative Time
6.Study on assessment methods for acetabular cup size in total hip arthroplasty.
Jinzi WANG ; Wenju CHANG ; Pei ZHANG ; Xiang LI ; Yong ZHANG ; Shuoshuo ZHANG ; Hai DING
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(2):163-167
OBJECTIVE:
To evaluate precise assessment methods for predicting the optimal acetabular cup size in total hip arthroplasty (THA).
METHODS:
A clinical data of 73 patients (80 hips) who underwent primary THA between December 2022 and July 2024 and met the inclusion criteria was analyzed. There were 39 males and 34 females with an average age of 66.3 years (range, 56-78 years). Among them, 66 cases were unilateral THA and 7 were bilateral THAs. There were 29 patients (34 hips) of osteoarthritis, 35 patients (35 hips) of femoral neck fractures, and 9 patients (11 hips) of osteonecrosis of the femoral head. Based on anteroposterior pelvic X-ray films, three methods were employed to predict acetabular cup size, including preoperative template planning, radiographic femoral head diameter (FHD) measurement, and intraoperative FHD measurement. The predicted acetabular cup sizes from these methods were compared with the actual implanted sizes.
RESULTS:
The predicted acetabular cup sizes using the preoperative template planning, radiographic FHD measurement, and intraoperative FHD measurement were (51.25±2.81), (49.72±3.11), and (49.90±2.74) mm, respectively, compared to the actual implanted cup size of (50.57±2.74) mm, with no significant difference ( P>0.05). Regarding agreement with the actual implanted cup size, the preoperative template planning achieved exact matches in 35 hips (43.75%), one-size deviation in 41 hips (51.25%), and two-size deviations in 4 hips (5%); the radiographic FHD measurement achieved exact matches in 12 hips (15%), one-size deviation in 57 hips (71.25%), and two-size deviations in 11 hips (13.75%); and the intraoperative FHD measurement achieved exact matches in 26 hips (32.5%), one-size deviation in 52 hips (65%), and two-size deviations in 2 hips (2.5%). There were significant differences in agreement distributions between the three methods and the actual implanted cup sizes ( H=18.579, P<0.001).
CONCLUSION
The intraoperative FHD measurement, as a simple, cost-effective, and accurate method, effectively guides acetabular cup selection, reduces the risk of prosthesis wear, enhances postoperative joint stability.
Humans
;
Arthroplasty, Replacement, Hip/instrumentation*
;
Male
;
Female
;
Middle Aged
;
Acetabulum/diagnostic imaging*
;
Aged
;
Hip Prosthesis
;
Prosthesis Design
;
Femur Head/surgery*
;
Osteoarthritis, Hip/surgery*
;
Radiography
;
Femoral Neck Fractures/surgery*
;
Femur Head Necrosis/surgery*
7.Molecular mechanism of magnesium alloy promoting macrophage M2 polarization through modulation of PI3K/AKT signaling pathway for tendon-bone healing in rotator cuff injury repair.
Xianhao SHENG ; Wen ZHANG ; Shoulong SONG ; Fei ZHANG ; Baoxiang ZHANG ; Xiaoying TIAN ; Wentao XIONG ; Yingguang ZHU ; Yuxin XIE ; Zi'ang LI ; Lili TAN ; Qiang ZHANG ; Yan WANG
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(2):174-186
OBJECTIVE:
To evaluate the effect of biodegradable magnesium alloy materials in promoting tendon-bone healing during rotator cuff tear repair and to investigate their potential underlying biological mechanisms.
METHODS:
Forty-eight 8-week-old Sprague Dawley rats were taken and randomly divided into groups A, B, and C. Rotator cuff tear models were created and repaired using magnesium alloy sutures in group A and Vicryl Plus 4-0 absorbable sutures in group B, while only subcutaneous incisions and sutures were performed in group C. Organ samples of groups A and B were taken for HE staining at 1 and 2 weeks after operation to evaluate the safety of magnesium alloy, and specimens from the supraspinatus tendon and proximal humerus were harvested at 2, 4, 8, and 12 weeks after operation. The specimens were observed macroscopically at 4 and 12 weeks after operation. Biomechanical tests were performed at 4, 8, and 12 weeks to test the ultimate load and stiffness of the healing sites in groups A and B. At 2, 4, and 12 weeks, the specimens were subjected to the following tests: Micro-CT to evaluate the formation of bone tunnels in groups A and B, HE staining and Masson staining to observe the regeneration of fibrocartilage at the tendon-bone interface after decalcification and sectioning, and Goldner trichrome staining to evaluate the calcification. Immunohistochemical staining was performed to detect the expressions of angiogenic factors, including vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2), as well as osteogenic factors at the tendon-bone interface. Additionally, immunofluorescence staining was used to examine the expressions of Arginase 1 and Integrin beta-2 to assess M1 and M2 macrophage polarization at the tendon-bone interface. The role of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in tendon-bone healing was further analyzed using real-time fluorescence quantitative PCR.
RESULTS:
Analysis of visceral sections revealed that magnesium ions released during the degradation of magnesium alloys did not cause significant toxic effects on organs such as the heart, liver, spleen, lungs, and kidneys, indicating good biosafety. Histological analysis further demonstrated that fibrocartilage regeneration at the tendon-bone interface in group A occurred earlier, and the amount of fibrocartilage was significantly greater compared to group B, suggesting a positive effect of magnesium alloy material on tendon-bone interface repair. Additionally, Micro-CT analysis results revealed that bone tunnel formation occurred more rapidly in group A compared to group B, further supporting the beneficial effect of magnesium alloy on bone healing. Biomechanical testing showed that the ultimate load in group A was consistently higher than in group B, and the stiffness of group A was also greater than that of group B at 4 weeks, indicating stronger tissue-carrying capacity following tendon-bone interface repair and highlighting the potential of magnesium alloy in enhancing tendon-bone healing. Immunohistochemical staining results indicated that the expressions of VEGF and BMP-2 were significantly upregulated during the early stages of healing, suggesting that magnesium alloy effectively promoted angiogenesis and bone formation, thereby accelerating the tendon-bone healing process. Immunofluorescence staining further revealed that magnesium ions exerted significant anti-inflammatory effects by regulating macrophage polarization, promoting their shift toward the M2 phenotype. Real-time fluorescence quantitative PCR results demonstrated that magnesium ions could facilitate tendon-bone healing by modulating the PI3K/AKT signaling pathway.
CONCLUSION
Biodegradable magnesium alloy material accelerated fibrocartilage regeneration and calcification at the tendon-bone interface in rat rotator cuff tear repair by regulating the PI3K/AKT signaling pathway, thereby significantly enhancing tendon-bone healing.
Animals
;
Rotator Cuff Injuries/metabolism*
;
Rats, Sprague-Dawley
;
Signal Transduction
;
Wound Healing/drug effects*
;
Alloys/pharmacology*
;
Rats
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Rotator Cuff/metabolism*
;
Macrophages/metabolism*
;
Magnesium/pharmacology*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Vascular Endothelial Growth Factor A/metabolism*
;
Male
;
Biocompatible Materials
;
Bone Morphogenetic Protein 2/metabolism*
8.Effect of autologous osteochondral tissue and periosteum transplantation on tendon-bone healing of rotator cuff in rabbits.
Sen FANG ; Mingtao ZHANG ; Xudong YANG ; Cairang DAOJI ; Mingchun LI ; Zhixuan NIAN ; Junwen LIANG ; Xiangdong YUN
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(2):187-192
OBJECTIVE:
To investigate the effect of autologous osteochondral tissue and periosteum transplantation on tendon-bone healing of rotator cuff in rabbits.
METHODS:
Twenty-four male New Zealand white rabbits were randomly divided into autologous osteochondral tissue and periosteum transplantation group (experimental group, n=12) and simple suture group (control group, n=12). Both groups were subjected to acute supraspinatus tendon injury and repaired with corresponding techniques. At 4, 8, and 12 weeks after operation, 4 specimens from each group were taken from the right shoulder joint for histological examination (HE staining, Masson staining, and Safranin O-fast green staining), and the left shoulder was subjected to biomechanical tests (maximum tensile load and stiffness).
RESULTS:
Both groups of animals survived until the completion of the experiment after operation. At 4 weeks after operation, both groups showed less collagen fibers and disorder at the tendon-bone junction. At 8 weeks, both groups showed reduced inflammation at the tendon-bone junction, with more organized and denser collagen fibers and chondrocytes. The experimental group showed better results than the control group. At 12 weeks, the experimental group showed typical tendon-bone transition structure, with increased generation of collagen fibers and chondrocytes, and the larger cartilage staining area. Both groups showed an increase in maximum tensile load and stiffness over time ( P<0.05). The stiffness at 4 weeks and the maximum tensile load at 4, 8, and 12 weeks in the experimental group were superior to control group, and the differences were significant ( P<0.05). There was no significant difference in stiffness at 8, 12 weeks between the two groups ( P>0.05).
CONCLUSION
Autologous osteochondral tissue and periosteum transplantation can effectively promote the fiber and cartilage regeneration at the tendon-bone junction of rotator cuff and improve the biomechanical effect of shoulder joint in rabbits.
Animals
;
Rabbits
;
Male
;
Wound Healing
;
Transplantation, Autologous
;
Periosteum/transplantation*
;
Rotator Cuff Injuries
;
Rotator Cuff/surgery*
;
Tendons/surgery*
;
Biomechanical Phenomena
;
Chondrocytes/transplantation*
;
Tendon Injuries/surgery*
;
Tensile Strength
9.Correlation analysis of anterior tibiotalar fat pad classification and anterior talofibular ligament injury based on MRI.
Lei ZHANG ; Junqiu WANG ; Wen LI ; Yu XIA
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(3):271-277
OBJECTIVE:
To investigate the correlation between the anterior talofibular ligament (ATFL) injury and the pathological changes of the anterior tibiotalar fat pad (ATFP) based on MRI.
METHODS:
The clinical and imaging data of 217 patients with ankle sprain who met the selection criteria between January 2019 and March 2024 were retrospectively analyzed. There were 113 males and 104 females with an average age of 38.2 years ranging from 18 to 60 years. Patients were divided into mild group ( n=106), moderate group ( n=63), and severe group ( n=48) according to the degree of ATFL injury. There was no significant difference in gender, side, and body mass index among the 3 groups ( P>0.05). The age of the mild group was significantly older than that of the moderate and severe groups ( P<0.05). The imaging parameters including the longest and shortest sagittal axis, the largest thickness, the longest and shortest transverse axis, the ATFP area, the area of ATFP high-signal region, and the anterior distal tibial angle (ADTA) were measured according to the MRI and X-ray films of patients. According to the morphology of ATFP, the patients were divided into type Ⅰ ( n=128), type Ⅱ ( n=73), and type Ⅲ ( n=16) based on the severity of the lesions. The distribution of ATFP types, ATFP area, area of ATFP high-signal region, and the ratio of area of ATFP high-signal region to ATFP area at the same level were statistically analyzed and compared among different ATFL injury groups. Additionally, radiographic parameters were compared across different ATFP types. Spearman rank correlation analysis was used to assess the relationships between ATFP area, area of ATFP high-signal region, and the ratio of area of ATFP high-signal region to ATFP area at the same level with patient baseline data. Through analysis of the area under curve (AUC) of ROC, optimal variables were selected for quantification to predict ATFL injury.
RESULTS:
There were significant differences in ATFP types among different ATFL injury groups ( P<0.05). The mild group had a higher proportion of type Ⅰ, the moderate group had a higher proportion of type Ⅱ, and the severe group had higher proportions of both typeⅡ and type Ⅲ. No significant difference was found in ATFP area among the different ATFL injury groups ( P>0.05). However, the area of ATFP high-signal region and the ratio of area of ATFP high-signal region to ATFP area at the same level were significantly lower in the mild group compared to the moderate and severe groups ( P<0.05). Except for the longest sagittal axis, maximum thickness, and longest transverse axis, which were significantly smaller in ATFP types Ⅱ and Ⅲ compared to type Ⅰ ( P<0.05), there was no significant difference in the remaining radiographic parameters among the different ATFP types ( P>0.05). Spearman rank correlation analysis revealed that ATFP area was negatively correlated with patient gender ( P<0.05), while area of ATFP high-signal region and the ratio of area of ATFP high-signal region to ATFP area at the same level were negatively correlated with patient age ( P<0.05). Through analysis of the AUC for the response variable ATFP injury, the combined diagnostic AUC of ROC for the reciprocal of the maximum thickness and the reciprocal of the area of ATFP high-signal region was 0.839 (asymptotic P<0.001). The corresponding cutoff value when the Youden index reached its maximum was 0.570 3.
CONCLUSION
As the severity of ATFL injury increases, the ATFP undergoes gradual morphological and functional changes. Classification based on ATFP types can assist in assessing the level of ATFL injury, thereby aiding in the prevention of post-traumatic osteoarthritis.
Humans
;
Male
;
Female
;
Adult
;
Magnetic Resonance Imaging/methods*
;
Middle Aged
;
Retrospective Studies
;
Adipose Tissue/pathology*
;
Adolescent
;
Young Adult
;
Lateral Ligament, Ankle/diagnostic imaging*
;
Ankle Injuries/pathology*
10.Finite element analysis of impact of bone mass and volume in low-density zone beneath tibial plateau on cartilage and meniscus in knee joint.
Longfei HAN ; Wenyuan HOU ; Shun LU ; Zijun ZENG ; Kun LIN ; Mingli HAN ; Guifeng LUO ; Long TIAN ; Fan YANG ; Mincong HE ; Qiushi WEI
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(3):296-306
OBJECTIVE:
To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint.
METHODS:
The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions.
RESULTS:
The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone.
CONCLUSION
The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans
;
Finite Element Analysis
;
Knee Joint/physiology*
;
Tibia/anatomy & histology*
;
Cartilage, Articular/physiology*
;
Menisci, Tibial/physiopathology*
;
Tomography, X-Ray Computed
;
Osteoarthritis, Knee/diagnostic imaging*
;
Weight-Bearing
;
Bone Density
;
Adult
;
Stress, Mechanical
;
Male
;
Middle Aged
;
Biomechanical Phenomena
;
Female

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