Objective:To investigate how age and nail-tract volumetric bone mineral density (vBMD) are associated with postoperative mechanical performance of proximal femoral nail anti-rotation (PFNA-Ⅱ) fixation for geriatric intertrochanteric fractures using a finite-element analysis.Methods:Fifteen elderly patients with intertrochanteric fracture of the femur were selected for this study. They were 11 females and 4 males and divided into 5 groups based on their ages ( n=3): 55-year-old, 65-year-old, 75-year-old, 85-year-old, and 95-year-old groups. After three-dimensional models of the proximal femur were constructed using the preoperative CT data of their healthy contralateral hip, 31-A1.2 fractures of the AO/OTA type were created and PFNA-Ⅱ fixations simulated. Two loading schemes were created: graded quasi-static axial loads (700 N, 1,400 N, 2,100 N, and 2,800 N) were applied to compute equivalent plastic strain volumes in the femoral head region; displacement-controlled loading was applied to failure to derive load-displacement curves for stiffness and the maximum failure load. Nail-tract vBMD and regional hip vBMDs were measured by quantitative CT. Pearson correlation analysis was conducted to investigate the associations of age and nail-tract vBMD with the aforementioned mechanical indicators. Results:Under the same load, compared with the 55-year-old, 65-year-old, and 75-year-old groups, the plastic strain unit volumes of the fracture models in the 85-year-old and 95-year-old groups increased significantly. Under a load of 700 N, no plastic strain was observed in the fracture models in the 55-year-old, 65-year-old, and 75-year-old groups, while an average plastic strain of approximately 50 mm 3 was observed in the fracture models in the 85-year-old group. Under a load of 2,800 N, the high strain areas in the fracture models in the 85-year-old and 95-year-old groups were mainly concentrated at the tip of the head nail and the junction between the head nail and the main nail. Load-displacement curves showed a marked reduction in the failure load in patients aged ≥85 years. Under loads of 1,400 N, 2,100 N, and 2,800 N, there was a strong association between the nail-tract vBMD and the volume of the plastic strain unit ( r=-0.82, -0.88, -0.89, respectively), which was stronger than those for total-hip vBMD. Conclusions:Finite-element analysis indicates that age and nail-tract vBMD are closely related to local plastic strain and overall stiffness of the proximal femur after PFNA-Ⅱ fixation for the geriatric intertrochanteric fractures. Patients aged ≥85 years old are more prone to plastic yielding, which compromises fixation stability.

Dental implantology has developed rapidly for over half a century,since pure titanium(99.7％)dental cylindrical threaded implants were exploited and osseointegration was introduced in 1960s by Prof.Br?nemark.The long term retention rates of 10 years or more are over 95％.However,the biological complications jeopardize the long term effects of dental implant treatment seriously.The prevalence of dental implant biological complications varies greatly among different reports resulting from the disparities on the defini-tions of dental implant biological complications.After analyzing and summarizing the major opinions proposed internationally in recent years,the consensus for the definition of dental implant biological complications has been reached.Generally the dental implant biologi-cal implications can be classified into early stage(before restoration)biological complications and late stage(after restoration)biological complications.The early stage biological complications include acute and chronic infections,pain,soft tissue deficiency,and osseointegration failure,etc.The late stage complications include peri-implant diseases(peri-implant mucositis and peri-implantitis),soft tissue deficiency around implant,implant loosening and dropping off,etc.The various risk factors related to different dental implant biological complications,the strategies of the prevention and treatment for the dental implant biological complications have been discussed comprehensively,and the consensus has been reached.It is aimed to advocate the dentist to pay more attention to the early prevention of the biological implant complications,to promote more researches on the implant biological complications,and to help elevate the level of dental implantology in our country.

Dental implantology has developed rapidly for over half a century,since pure titanium(99.7％)dental cylindrical threaded implants were exploited and osseointegration was introduced in 1960s by Prof.Br?nemark.The long term retention rates of 10 years or more are over 95％.However,the biological complications jeopardize the long term effects of dental implant treatment seriously.The prevalence of dental implant biological complications varies greatly among different reports resulting from the disparities on the defini-tions of dental implant biological complications.After analyzing and summarizing the major opinions proposed internationally in recent years,the consensus for the definition of dental implant biological complications has been reached.Generally the dental implant biologi-cal implications can be classified into early stage(before restoration)biological complications and late stage(after restoration)biological complications.The early stage biological complications include acute and chronic infections,pain,soft tissue deficiency,and osseointegration failure,etc.The late stage complications include peri-implant diseases(peri-implant mucositis and peri-implantitis),soft tissue deficiency around implant,implant loosening and dropping off,etc.The various risk factors related to different dental implant biological complications,the strategies of the prevention and treatment for the dental implant biological complications have been discussed comprehensively,and the consensus has been reached.It is aimed to advocate the dentist to pay more attention to the early prevention of the biological implant complications,to promote more researches on the implant biological complications,and to help elevate the level of dental implantology in our country.

Objective:To investigate how age and nail-tract volumetric bone mineral density (vBMD) are associated with postoperative mechanical performance of proximal femoral nail anti-rotation (PFNA-Ⅱ) fixation for geriatric intertrochanteric fractures using a finite-element analysis.Methods:Fifteen elderly patients with intertrochanteric fracture of the femur were selected for this study. They were 11 females and 4 males and divided into 5 groups based on their ages ( n=3): 55-year-old, 65-year-old, 75-year-old, 85-year-old, and 95-year-old groups. After three-dimensional models of the proximal femur were constructed using the preoperative CT data of their healthy contralateral hip, 31-A1.2 fractures of the AO/OTA type were created and PFNA-Ⅱ fixations simulated. Two loading schemes were created: graded quasi-static axial loads (700 N, 1,400 N, 2,100 N, and 2,800 N) were applied to compute equivalent plastic strain volumes in the femoral head region; displacement-controlled loading was applied to failure to derive load-displacement curves for stiffness and the maximum failure load. Nail-tract vBMD and regional hip vBMDs were measured by quantitative CT. Pearson correlation analysis was conducted to investigate the associations of age and nail-tract vBMD with the aforementioned mechanical indicators. Results:Under the same load, compared with the 55-year-old, 65-year-old, and 75-year-old groups, the plastic strain unit volumes of the fracture models in the 85-year-old and 95-year-old groups increased significantly. Under a load of 700 N, no plastic strain was observed in the fracture models in the 55-year-old, 65-year-old, and 75-year-old groups, while an average plastic strain of approximately 50 mm 3 was observed in the fracture models in the 85-year-old group. Under a load of 2,800 N, the high strain areas in the fracture models in the 85-year-old and 95-year-old groups were mainly concentrated at the tip of the head nail and the junction between the head nail and the main nail. Load-displacement curves showed a marked reduction in the failure load in patients aged ≥85 years. Under loads of 1,400 N, 2,100 N, and 2,800 N, there was a strong association between the nail-tract vBMD and the volume of the plastic strain unit ( r=-0.82, -0.88, -0.89, respectively), which was stronger than those for total-hip vBMD. Conclusions:Finite-element analysis indicates that age and nail-tract vBMD are closely related to local plastic strain and overall stiffness of the proximal femur after PFNA-Ⅱ fixation for the geriatric intertrochanteric fractures. Patients aged ≥85 years old are more prone to plastic yielding, which compromises fixation stability.

Objective:To explore the correlation between hip muscle factors measured with CT imaging and recovery of independent mobility within 1 year after surgery in elderly patients with hip fractures.Methods:A prospective cohort study was conducted on the clinical data of 680 elderly patients with hip fractures admitted to Beijing Jishuitan Hospital of Capital Medical University from November 2018 to December 2019. The patients were assigned to dependent group and assistant group according to whether they regained pre-injury independent mobility within 1 year after surgery. Gender, age, body mass index, personal history, living habits, past diseases, Charlson comorbidity index, laboratory test indicators, fracture types, anesthesia types, surgical methods, rehabilitation training, time from injury to surgery, and hip muscle parameters in both groups were recorded. OsiriX software was employed in the measurement of the hip muscles to measure the muscle area and density of the gluteus maximus and gluteus medius/minimus on CT images, and the average values were calculated as hip muscle area and density. Then the variables of hip muscle area and density were converted seperately to gender-normalized Z-scores, and were divided into high-area group ( Z&ge;0) and low-area group ( Z<0), and high-density group ( Z&ge;0) and low-density group ( Z<0) respectively. Observable variables were primarily analyzed using univariate analysis between the independent group and assistant group. Those variables with statistically significant differences in the univariate analysis or would potentially affect mobility recovery according to previous researches although there were no statistical significance were included in a multivariate Logistic regression analysis. Three Logistic regression models were designed (Model 1 uncorrected, Model 2 corrected for gender, age and body mass index, Model 3 corrected for variables in Model 2 and other variables included after above-mentioned analysis) to analyze whether muscle parameters were risk factors for recovery of independent mobility. Additionally, generalized estimating equations were used for repeated measurement to analyze the correlation between hip muscle area and recovery of independent mobility after surgery. Results:Compared to the assistant group, the independent group were younger in age, with lower rate of living alone, being housebound, cognitive impairment, and Charlson comorbidity index, lower level of hemoglobin and albumin, higher rate of femoral neck fractures, lower rate of internal fixation, shorter time from injury to surgery, larger hip muscle area, and higher hip muscle density ( P<0.05 or 0.01). Multivariate Logistic regression analysis showed that, in the fully corrected Model 3, only hip muscle area remained significantly correlated with recovery of independent mobility ( P<0.05), while no significant difference was found between the high-density group and low-density group ( P>0.05). In the repeated measurement, patients in the high-area group were 1.84 times more likely to restore independent mobility than those in the low-area group ( OR=1.84, 95% CI 1.33, 2.53, P<0.01). Conclusions:Hip muscle area measured with CT imaging is closely correlated to the recovery of independent mobility within 1 year after surgery in elderly patients with hip fractures. Moreover, larger hip muscle area indicates a larger likelihood of recovery of independent mobility.

Objective:To investigate the clinical efficacy and safety of pulmonary rehabilitation in elderly patients with chronic obstructive pulmonary disease(COPD)who are undergoing long-term home oxygen therapy.Methods:The study included a total of 60 elderly patients with COPD who were successfully discharged after receiving treatment at the First Hospital of Shanxi Medical University from November 2021 to October 2022.The enrolled patients were randomly divided into two groups: the pulmonary rehabilitation group and the control group, with 30 patients in each group.The allocation was determined using a random number table and prospective research methods.Patients in the pulmonary rehabilitation group underwent a 12-week pulmonary rehabilitation training program, while patients in the control group received pulmonary rehabilitation education and nutrition education.The general data of the two groups of patients were compared, including lung function parameters[forced expiratory volume in one second(FEV 1), forced vital capacity(FVC), forced expiratory volume in one second to forced vital capacity ratio(FEV 1/FVC), and percentage of predicted forced expiratory volume in one second(FEV 1%pred)], blood gas analysis[partial pressure of arterial oxygen(PaO 2), partial pressure of arterial carbon dioxide(PaCO 2), arterial oxygen saturation(SaO 2)], 6-minute walking distance(6MWD), grip strength, 5-round sit to stand test(5R-STST), modified British medical research council(mMRC)score, COPD assessment test(CAT)score, closed cycles test(CCT), Berg balance scale(BBS), and safety measures.These parameters were assessed before and after the intervention. Results:A total of 29 patients in the pulmonary rehabilitation group and 28 patients in the control group completed the study.The general data between the two groups showed no significant difference(all P>0.05).After the intervention, patients in the pulmonary rehabilitation group showed improvements in FEV 1/FVC, PaO 2, PaCO 2, SaO 2, 6MWD, grip strength, 5R-STST, CAT, CCT, and BBS( t=-2.242, -4.630, W=-3.439, t=-6.512, -10.563, -6.197, W=-3.968, t=10.847, -7.334, W=-4.189, all P<0.05).Additionally, 6MWD, CAT, and CCT showed significant improvement after the intervention compared to the control group( t=-2.104, 2.183, 2.106, all P<0.05).No training-related adverse effects were observed during the study. Conclusions:The 12-week pulmonary rehabilitation program is shown to be effective for elderly patients with COPD who are undergoing long-term home oxygen therapy.This program helps to improve respiratory function, systemic symptoms, exercise endurance, muscle strength, and balance function.It is designed to be simple and easy to implement, allowing patients to achieve their training goals and improve their clinical symptoms.Additionally, the program has been found to be safe and well-tolerated by patients, making it a valuable intervention that should be promoted and widely applied.

The clinical data of one child with metanephric stromal tumor (MST) and BRAF V600E gene mutation admitted to the First Affiliated Hospital of Zhengzhou University in June 2022 was analyzed retrospectively.Literature was reviewed.The patient, a 2-year-old girl, was diagnosed with a tumor in the left abdomen.The maximum diameter of the tumor was 10.5 cm.A radical nephrectomy was performed on the left kidney, and postoperative pathology revealed MST.Microscopically, the tumor had no envelope and exhibited expansive growth.The tumor cells were fusiform or stellate, and nuclear division was visible in the cell-rich region.Dysplastic blood vessels were seen inside the tumor.The tumor cells around the blood vessels and invaginated renal tubules were arranged like onion skin.CD34 was detected positive by immunohistochemical staining, and BRAF V600E mutation was also detected positive by fluorescent polymerase chain reaction.A total of 21 relevant case reports were retrieved, including 16 in English and 5 in Chinese.Fifty-eight MST patients, including the one in this report were analyzed.These patients were aged 2 days to 15 years, with a median age of 2 years.Except for 2 patients with unknown sex, the ratio of male to female was about 1.4∶1.0.Most MST patients were asymptomatic, with an average tumor size of 5.3 cm.The tumor cell CD34 showed positive expression in different degrees.Eight patients received the BRAF V600E mutation detection, and the results were all positive.Fifty-eight patients underwent nephrectomy and were followed up for 0-156 months, of which 7 patients were assisted with radiotherapy and chemotherapy.During the follow-up, 1 patient died, and 1 patient had a relapse.MST is a rare benign renal stromal tumor. BRAF V600E mutations are detected in a variety of malignancies.This paper is the first to report MST with BRAF V600E mutation in China and points out the importance of molecular detection of BRAF mutation for accurate diagnosis of MST.

Objective:To evaluate the effect of the impaction of posterior wall on the prognosis following open reduction and internal fixation for fractures of acetabular posterior wall.Methods:A retrospective study was conducted to analyze the data from the 83 patients with fracture of acetabular posterior wall who had been consecutively treated by open reduction and internal fixation at Department of Orthopaedics and Traumatology, Beijing Jishuitan Hospital from January 2017 to December 2020. The patients were divided into 2 groups based on involvement of posterior wall impaction. In the impaction group of 33 cases, there were 26 males and 7 females with an age of (47.4±11.6) years; in the non-impaction group of 50 cases, there were 43 males and 7 females with an age of (41.3±12.0) years. The quality of postoperative fracture reduction, the function of the affected hip at the last follow-up, and the complication rate during follow-up were compared between the 2 groups. Multifactorial binary logistic regression and age subgroups were used to analyze the effects of posterior wall impaction on functional outcomes.Results:The age, rate of associated injuries in other body parts, and rate of posterior wall comminution in the impaction group were significantly higher than those in the non-impaction group ( P<0.05), but there was no statistically significant difference in other general data of patients between the 2 groups ( P>0.05). All patients were followed up for (44.5±13.3) months after surgery. The rate of anatomical reduction in the non-impaction group (96.0%, 48/50) was significantly higher than that in the impaction group (57.6%, 19/33) ( P<0.05), and the good and excellent rate by the modified Merle d'Aubigné & Postel scale at the last follow-up in the non-impaction group (84.0%, 42/50) was significantly higher than that in the impaction group (51.5%, 17/33) ( P<0.05). There was no significant difference in the incidence of complications between the 2 groups ( P>0.05). After adjusting for age and gender, the difference in hip function was still significantly different between the 2 groups ( OR=0.23, 95% CI: 0.06 to 0.79, P=0.020). The effect of posterior wall impaction on functional outcomes was statistically significant in patients aged &ge;50 years ( P=0.008), whereas the difference was not statistically significant in patients aged <50 years ( P=0.194). Conclusions:Compared with non-impaction ones, acetabular fractures of posterior wall impaction tend to lead to poorer quality of reduction, which in turn affects the postoperative recovery of hip joint function. The impact of impaction fractures on functional recovery is more significant in patients aged 50 years and above.

【Objective】 To investigate the clinicopathological features and prognosis of clear cell papillary renal cell carcinoma (CCPRCC). 【Methods】 The clinicopathological and follow-up data of 40 CCPRCC patients treated during Jun. 2011 and Oct.2021 were retrospectively analyzed. The prognosis was compared with that of 40 cases of clear cell renal cell carcinoma (ccRCC) and 19 cases of papillary renal cell carcinoma (PRCC) treated in the same period. Survival analysis was performed by Log-rank test and Kaplan-Meier survival curves were plotted. 【Results】 Among the 40 patients, 28 were male and 12 were female, aged 31-84 years; 38 cases had unilateral and 2 cases had bilateral tumors; 3 cases had multifocal lesions. All patients received surgery. The maximum diameter of the masses ranged from 3.0 to 95.0 mm, with an average of (27.6±18.1) mm. Pathological grade was Fuhrman 1-2 in all cases. Immunohistochemical tests were positive for CK7 and CA-IX. During the follow-up of 5-129 (average 56) months, 1 case died after bone metastasis, 2 had ipsilateral recurrence, and 1 developed primary esophageal cancer. CCPRCC patients had a significantly better prognosis than CCRCC (P<0.001) and PRCC (P=0.005) patients, while there was no significant difference in the prognosis between CCRCC and PRCC patients (P=0.93). 【Conclusions】 CCPRCC has low malignancy. The diagnosis relies on characteristic pathological and immunohistochemical features. Surgery is an effective treatment. CCPRCC has a better overall prognosis than CCRCC and PRCC.

Objective:To compare the short-term efficacy between our self-designed intelligent robot-assisted minimally invasive reduction system and conventional freehand reduction assisted by fluoroscopy in the treatment of unstable pelvic fractures by robot or fluoroscopy-assisted internal fixation with percutaneous screws.Methods:A prospective randomized controlled trial was conducted to include eligible 35 patients with unstable pelvic fracture who were admitted to Department of Orthopaedic Trauma, Beijing Jishuitan Hospital from December 2021 to October 2022. They were randomized into 2 groups. The observation group[17 cases, 10 males and 7 females with an age of (44.0±17.4) years] was treated with robot-assisted minimally invasive reduction, followed by robot-assisted or fluoroscopic internal fixation with percutaneous screws; the control group[18 cases, 12 males and 6 females with an age of (38.8±15.0) years] was treated with freehand reduction assisted by fluoroscopy, followed by robot-assisted or fluoroscopic internal fixation with percutaneous screws. The 2 groups were compared in terms of operation time, intraoperative bleeding, successful reduction, reduction quality, incidence of surgical complications and postoperative functional scores.Results:The 2 groups were comparable because there were no significant differences in the preoperative general data between them ( P>0.05). The intraoperative fluoroscopy frequency[(32.4±17.5) times] and fluoroscopy time [(19.8±10.4) s] in the observation group were significantly lower or shorter than those in the control group [(60.8±26.6) times and (38.2±16.1) s], and the rate of successful reduction in the observation group was 100.0% (17/17), significantly higher than that in the control group[72.2% (13/18)] ( P<0.05). There was no significant difference between the 2 groups in intraoperative bleeding, operation time, reduction error, excellent and good rate of reduction after operation by Matta scoring, or Majeed functional score at 12 weeks after operation ( P>0.05). Conclusion:In the treatment of unstable pelvic fractures, since our self-designed intelligent robot-assisted minimally invasive reduction system can plan autonomously the reduction paths and accomplish minimally invasive reduction of the fracture with 3D images real-time monitoring, it is advantageous over conventional reduction methods in a higher success rate and less radiation exposure.