Objective:To evaluate the stability of percutaneous screw fixation for minimally invasive treatment of intra-articular calcaneal fractures using three-dimensional finite element analysis.Methods:CT scan was performed on the calcaneus of a normal adult for three-dimensional reconstruction. The DICOM data were imported into Mimics software to establish a model of a Sanders type IIB intra-articular calcaneal fracture. Based on the Essex-Lopresti classification of posterior facet morphology, the model was subdivided into two subtypes: tongue-type and depression-type. The calcaneus was divided into four fragments: sustentaculum tali, posterior tuberosity, anterior process (three points), and posterior articular surface (one surface). Two types of fixation methods, classical lateral anatomical plates and combinations of percutaneous screws, were simulated and performed. A three-dimensional finite element analysis was conducted by applying a stress combination of 420 N on the posterior subtalar articular surface, 200 N on the middle subtalar articular surface, and 300 N at the Achilles tendon insertion point. The maximum displacement and von Mises stress values of each bone fragment and implant were recorded to evaluate the biomechanical stability. For clinical validation, 34 patients with Sanders type IIB calcaneal fractures from Orthopedics Department of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University were treated with percutaneous reduction and screw fixation using the following configurations.Results:Under simulated stress, the A4 group with medial support screws in the tongue-type fracture subgroup demonstrated minimal overall calcaneal displacement (0.22 mm) and internal fixation displacement (0.14 mm). For the depression-type, the B2 group with medial support screws showed lower maximum stress in the calcaneus and internal fixation, at 22.04 MPa and 41.14 MPa, respectively, along with the lowest overall displacement (0.14 mm). The peak stress of all groups of implants remained below the material yield strength. The A4 and B2 protocols were applied to 15 cases of tongue-type calcaneal fractures and 19 cases of collapse-type calcaneal fractures. At the final follow-up The American Orthopaedic Foot & Ankle Society ankle-hindfoot score scale was 86.1±5.82 and 87.2±5.18, respectively, while the visual analog scale for pain was 1.60±1.24 and 1.58±1.02, respectively.Conclusions:Percutaneous screw fixation provided reliable stability for Sanders type IIB calcaneal fractures. The fixation configuration incorporating a medial support screw offers superior biomechanical performance in both tongue-type and depression-type fractures, representing an optimized minimally invasive technique with strong clinical applicability.

Objective:To evaluate the stability of percutaneous screw fixation for minimally invasive treatment of intra-articular calcaneal fractures using three-dimensional finite element analysis.Methods:CT scan was performed on the calcaneus of a normal adult for three-dimensional reconstruction. The DICOM data were imported into Mimics software to establish a model of a Sanders type IIB intra-articular calcaneal fracture. Based on the Essex-Lopresti classification of posterior facet morphology, the model was subdivided into two subtypes: tongue-type and depression-type. The calcaneus was divided into four fragments: sustentaculum tali, posterior tuberosity, anterior process (three points), and posterior articular surface (one surface). Two types of fixation methods, classical lateral anatomical plates and combinations of percutaneous screws, were simulated and performed. A three-dimensional finite element analysis was conducted by applying a stress combination of 420 N on the posterior subtalar articular surface, 200 N on the middle subtalar articular surface, and 300 N at the Achilles tendon insertion point. The maximum displacement and von Mises stress values of each bone fragment and implant were recorded to evaluate the biomechanical stability. For clinical validation, 34 patients with Sanders type IIB calcaneal fractures from Orthopedics Department of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University were treated with percutaneous reduction and screw fixation using the following configurations.Results:Under simulated stress, the A4 group with medial support screws in the tongue-type fracture subgroup demonstrated minimal overall calcaneal displacement (0.22 mm) and internal fixation displacement (0.14 mm). For the depression-type, the B2 group with medial support screws showed lower maximum stress in the calcaneus and internal fixation, at 22.04 MPa and 41.14 MPa, respectively, along with the lowest overall displacement (0.14 mm). The peak stress of all groups of implants remained below the material yield strength. The A4 and B2 protocols were applied to 15 cases of tongue-type calcaneal fractures and 19 cases of collapse-type calcaneal fractures. At the final follow-up The American Orthopaedic Foot & Ankle Society ankle-hindfoot score scale was 86.1±5.82 and 87.2±5.18, respectively, while the visual analog scale for pain was 1.60±1.24 and 1.58±1.02, respectively.Conclusions:Percutaneous screw fixation provided reliable stability for Sanders type IIB calcaneal fractures. The fixation configuration incorporating a medial support screw offers superior biomechanical performance in both tongue-type and depression-type fractures, representing an optimized minimally invasive technique with strong clinical applicability.

Objective:To investigate the application value of the maximum standardized uptake value (SUVmax) of 18F prostate-specific membrane antigen (PSMA) PET/CT combined with the minimum apparent diffusion coefficient (ADCmin) of biparametric magnetic resonance imaging (bpMRI) in predicting pathological upgrading after radical prostatectomy (RP) for prostate cancer. Methods:The data of 89 patients with localized prostate cancer treated at Beijing Hospital from April 2019 to October 2023 were retrospectively analysed. The average age of patients was (68.4±7.0) years old, with prostate-specific antigen (PSA) level of 7.7 (5.4, 12.9) ng/ml, prostate volume of 34.6 (26.9, 47.1) ml, tumor diameter of 1.3 (1.0, 1.8) cm, prostate imaging reporting and data system(PI-RADS) score of 5 in 29 cases (32.6%), clinical stage ≥T 3 in 13 cases (14.6%). There were 31 cases (34.8%) in group 1 of targeted biopsy International Society of Urological Pathology (ISUP)grading groups, 36 cases (40.4%) in group 2, 11 cases (12.4%) in group 3, and 11 cases (12.4%) in group 4. All patients underwent 18F-PSMA PET/CT and bpMRI examinations before RP. The index lesion, identified as the highest Gleason score in pathological whole-mount sections, were outlined. SUVmax and ADCmin values were calculated from the images' region of interest. Pathological upgrading was defined as the post-RP grade group higher than the targeted-biopsy grade group. Clinical data of patients with and without pathological upgrading were compared. Spearman correlation coefficient analysis was used to assess the correlation between SUVmax and ADCmin. Multivariate logistic regression analysis was conducted to evaluate the factors influencing pathological upgrading. Receiver operating characteristic (ROC) curve analysis was employed to assess the predictive value of each indicator for pathological upgrading. Results:Among the 89 cases, 31 cases (34.8%) experienced pathological upgrading. Compared with the patients without pathological upgrading, the SUVmax [11.3 (8.1, 16.4) vs. 6.7 (4.6, 9.2)], SUVmax/ADCmin ratio [3.1 (2.0, 4.6) vs. 1.4 (0.9, 2.1)], PSA [9.8 (6.3, 15.6) ng/ml vs. 7.1 (5.1, 10.5) ng/ml], PSA density [0.3 (0.2, 0.5) ng/ml 2 vs. 0.2 (0.1, 0.3) ng/ml 2], and post-RP ISUP grade group [≥3 group 17 cases (54.8%) vs. 13 cases(22.4%) ]were higher in patients with pathological upgrading, while ADCmin [3.8 (3.0, 5.3) ×10 -4 mm 2/s vs. 5.2 (3.6, 6.1)×10 -4 mm 2/s] and targeted biopsy ISUP grade group [≤2 group 27 cases(87.1%) vs. 40 cases(69.0%) ] were lower (all P<0.05). Spearman analysis showed a negative correlation between SUVmax and ADCmin ( R = -0.227, P = 0.032). Multivariate logistic regression analysis revealed that SUVmax ( OR = 1.108, 95% CI 1.020-1.238), ADCmin ( OR=0.607, 95% CI 0.390-0.874), and SUVmax/ADCmin ratio ( OR = 1.815, 95% CI 1.282-2.949) independently predicted pathological upgrading. The AUC of the SUVmax/ADCmin ratio for predicting pathological upgrading (AUC = 0.817) was higher than that of SUVmax (AUC = 0.774) and ADCmin (AUC=0.686), indicating a higher predictive efficiency. Conclusions:SUVmax, ADCmin, and SUVmax/ADCmin ratio can independently predict pathological upgrading in targeted biopsy of prostate cancer. The SUVmax/ADCmin ratio has a stronger predictive value for pathological upgrading.

Objective:To evaluate the safety of thymic surgery in patients aged 65 years and over.Methods:A total of 696 patients who underwent thymectomy/thymoma resection in the Department of Thoracic Surgery of Beijing Hospital from November 2011 to March 2022 were collected and divided into two groups according to the age of 65 years old.The preoperative course of disease, MG stage, dosage of pyridostigmine bromide, American College of Anesthesiologists(ASA)score, surgical method, intraoperative bleeding, postoperative drainage, postoperative complications, Clavien-dindo score(CDC), and myasthenic crisis were recorded and statistically analyzed.Results:A total of 696 patients were enrolled, including 364 males and 332 females, aged 15~86 years, with an average age of 49.1 years.There were 309 patients with thymoma, 565 patients with MG, and 178 patients with both.There were 124 cases in the elderly group(≥65 years old)and 572 cases in the non-elderly group(<65 years old). The incidence of thymoma was higher in the elderly group(54.8 % versus 42.1 %, χ2=6.664, P=0.010), while the incidence of MG was lower(67.7 % versus 84.1 %, χ2=17.827, P<0.001). The ASA score of the elderly group was higher than that of the non-elderly group( χ2=52.372, P=0.000), and the preoperative ventilation function FEV1 and FEV1/FVC were also significantly lower than those of the non-elderly group( z=8.187, 4.580, P=0.000 for all). The drainage volume in the first 3 days after operation and postoperative drainage tube time in the elderly group were significantly higher than those in the non-elderly group( P=0.018, P=0.003). The incidence of postoperative myasthenia crisis in the elderly group was higher than that in the non-elderly group( P=0.034). There was no significant difference in the incidence of postoperative complications between the two groups, but after Clavien-dindo classification, the score of the elderly group was higher than that of the non-elderly group( P=0.003). Although the ASA score and Clavien-dindo score of the elderly group were both higher than those of the non-elderly group, there was no correlation between the two. Conclusions:Although the preoperative ASA score and pulmonary function of elderly patients were poorer than those in the non-elderly group, while the incidence of postoperative myasthenia crisis was higher, and the incidence of postoperative complications was not higher, the Clavien-dindo classification, however, was higher in elderly patients than that of the non-elderly group.After careful preoperative evaluation and strengthening perioperative management, most elderly patients can receive thymus surgery safely with acceptable risks.

Currently, thoracic endovascular aortic repair (TEVAR) is the first-line treatment for patients with complicated Stanford type B aortic dissections. However, TEVAR does not occlude the distal entry tear of dissections, and blood flow persists in the false lumen. Dissections might progress in some patients. Studies showed that distal entry tear increased the possibility of late aortic events during follow-up. Thus, treatment of distal entry tear is necessary in some high-risk patients after TEVAR. In this article, the current treatment strategies of distal entry tear are summarized, which include PETTICOAT, STABILISE, covered stent, fenestrated and branched stent-grafts, false lumen embolization, vascular occluder, and Knickerbocker. However, the number of the cases of most approaches is so limited that the indications and effectiveness need to be further studied. Selecting the right treatment for the right patient is of great importance.

Currently, thoracic endovascular aortic repair (TEVAR) is the first-line treatment for patients with complicated Stanford type B aortic dissections. However, TEVAR does not occlude the distal entry tear of dissections, and blood flow persists in the false lumen. Dissections might progress in some patients. Studies showed that distal entry tear increased the possibility of late aortic events during follow-up. Thus, treatment of distal entry tear is necessary in some high-risk patients after TEVAR. In this article, the current treatment strategies of distal entry tear are summarized, which include PETTICOAT, STABILISE, covered stent, fenestrated and branched stent-grafts, false lumen embolization, vascular occluder, and Knickerbocker. However, the number of the cases of most approaches is so limited that the indications and effectiveness need to be further studied. Selecting the right treatment for the right patient is of great importance.

Objective To compare prenatal ultrasonography and MRI in view of the accuracy in the diag-nosis of congenital cystic adenmatiod malformation(CAMM)of the lung. Methods From January 2014 to Octo-ber 2015,68 fetus who were examined with both prenatal ultrasonography and MRI and diagnosed as CAMM by pathological findings after operation or autopsy in our study. Taking the final pathological diagnosis of fetal CCAM genotyping as the gold standard,the accuracy of prenatal ultrasonography and MRI were compared in the diagnosis of CAMM of the lung.P<0.05 was considered as statistically significant. Results The alignment degree of prena-tal ultrasound in the diagnosis of CAMM was significantly larger than that of MRI examination to the pathological di-agnosis.Conclusion Prenatal ultrasound is an important method for diagnosing CCAM before pregnancy with high accuracy and affordability.

Objective To determine the incidence and clinical features of headache after carotid endarterectomy (CEA).Methods A retrospective analysis was made on the data of patients undergoing CEA in the Department of Vascular Surgery,Peking Union Medical College Hospital from Jan 2014 to Jan 2015.There were 119 males and 24 females,including 97 cases of symptomatic carotid stenosis and 110 cases of severe carotid stenosis.Results The incidence of newly emergent headache after surgery was 44％ (63/143).The earliest time of headache was 30 minutes after surgery and the latest was 6 days after surgery.95％ of headache occurred within 48 hours after surgery (60/63).79.4％ (50/63) of the headache lay ipsilaterally with CEA,and bilateral headache accounted for 20.6％ (13/63).Severe headache accounted for 4.8％ (3/63),all were ipsilaterally frontal and temporal headache,complicating central nervous system symptoms.Conclusions After CEA headache is a common clinical symptom.Most were mild to moderate and unilateral,which can be relieved spontaneously.Cerebral hemodynamics need to be further examined to differentiate the different pathological states of severe headache on the operative side after CEA because of the high risk of developing hyperperfusion syndrome or cerebral infarction.History of TIA or stroke is the risk factor of post-CEA headache.

Objective To investigate the value of prenatal ultrasound in prognosis assessment of congenital diaphragmatic hernia.Methods The ultrasonographic features of 65 fetuses with congenital diaphragmatic hernia were analyzed,which were confirmed by after birth surgery or examination.The lung-to-head ratio (LHR) of unaffected side and O/E LHR (LHR compared to normal fetuses on same gestational weeks) were obtained,and then the relationship with the prognosis of neonates were analyzed.Results In 65 cases,45 fetuses survived and 8 fetuses died after surgery,while 12 cases did not undergo surgery and death promptly.Overall mortality was 30.77％ (20/65).In 12 hepatic intrathoracic type of diaphragmatic hernia cases,the mortality rate was 66.67 ％ (8/12).In 53 hepatic intra-abdominal type of diaphragmatic hernia cases,the mortality rate was 22.64 ％ (12/53).In 9 cases combined with other structural abnormalities,there were 8 cases were dead and 6 cases (6/8) with abnormal chest structure.LHR values were from 0.40 to 2.72,the average value was 1.59±0.69.It showed statistical difference on the mortality rate in fetus of congenital diaphragmatic hernia with different LHR (x2 =19.360,P＜0.001),The mortality rate in fetal of congenital diaphragmatic hernia with LHR 1.0 or less was higher than that with LHR ＞1.0.O/E LHR measurement values were from 23％ to 90％ and the average value was (58.25±17.61) ％.It showed statistical difference on the mortality rate in fetus of congenital diaphragmatic hernia with different O/E LHR (x2 15.261,P=0.002).The mortality rate in fetal of congenital diaphragmatic hernia with O/E LHR ≤45 ％ was higher than that with O/E LHR＞45 ％.Conclusion The prenatal ultrasound can be used to diagnose congenital diaphragmatic hernia,and to assess the development of unaffected lung and prognosis.