This review aimed to provide a comprehensive analysis of the etiology, epidemiology, pathology, and conventional treatment of heterotopic ossification (HO), especially emerging potential therapies. HO is the process of ectopic bone formation at non-skeletal sites. HO can be subdivided into two major forms, acquired and hereditary, with acquired HO predominating. Hereditary HO is a rare and life-threatening genetic disorder, but both acquired and hereditary form can cause severe complications, such as peripheral nerve entrapment, pressure ulcers, and disability if joint ankylosis develops, which heavily contributes to a reduced quality of life. Modalities have been proposed to treat HO, but none have emerged as the gold standard. Surgical excision remains the only effective modality; however, the optimal timing is controversial and may cause HO recurrence. Recently, potential therapeutic strategies have emerged that focus on the signaling pathways involved in HO, and small molecule inhibitors have been shown to be promising. Moreover, additional specific targets, such as small interfering RNAs (siRNAs) and non-coding RNAs, could be used to effectively block HO or develop combinatorial therapies for HO.
Humans ; Ossification, Heterotopic/genetics*

Objective To explore the protective effect of 7,8-dihydroxyflavone(7,8-DHF)on the retina of diabetic rats and its mechanism.Methods A total of 18 SPF-grade male Sprague-Dawley(SD)rats were selected and randomly divided into three groups:the normal group,the model group,and the experimental group,with six rats in each group.Rats in the normal group were fed with a normal diet,while those in the remaining two groups were fed with a high-fat emulsion through oral gavage continuously for 2 weeks to establish a diabetes model.Rats in the experimental group were provided with 7,8-DHF(5 mg?kg-1)by continuous intraperitoneal injection,while those in the normal and model groups were provided with an equal volume of normal saline.The rats in all groups received intervention once a day for 2 weeks.The changes in the body mass and fasting blood glucose(FBG)were observed before and after modeling.Besides,the changes in the retina of rats in each group were observed by fundus fluorescence angiography(FFA)after 2 weeks.Moreo-ver,the changes and apoptosis of retinal neuronal cells were detected by hematoxylin and eosin(HE)staining,CD31 im-munofluorescence,and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assays.Results After 2 weeks of continuous intervention,compared with the normal group,the body mass of rats in the model and experimental groups decreased(both P＜0.05),and the FBG increased significantly(both P＜0.05);compared with the model group,the experimental group showed an increase in the body mass(P＜0.05)and a decrease in the FBG(P＜0.05).The fundus photography and FFA of rats in the three groups did not reveal any fundus features of diabetic retinopathy.The HE staining results showed that the retina of rats in the normal and experimental groups was structurally intact,with neatly arranged cells and uniform thickness;the retinal structure of rats in the model group remained clear.However,the thickness of the inner layers of the retina of rats in the model group was thinner compared with the normal and experimental groups,exhibi-ting significant differences(both P＜0.05).The CD31 immunofluorescence assay results indicated that the CD31 immuno-fluorescence intensity values of rats in the three groups were roughly comparable,without significant differences(all P＞0.05).The TUNEL assay results suggested that the apoptosis of retinal neurons increased in rats in the model group com-pared with the normal group,exhibiting significant differences(P＜0.001);compared with the model group,the apoptosis of retinal neurons of rats in the experimental group decreased significantly,displaying significant differences(P＜0.001).Conclusion The apoptosis of retinal neurons in diabetic rats may precede vascular endothelial cell injury.7,8-DHF can improve the body mass,decrease the blood glucose level,and protect the retinal neurons in diabetic rats.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

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 investigate the association between quantitative CT-derived hip bone mineral density (BMD) and all-cause mortality in elderly women after hip fracture surgery.Methods:A retrospective study was conducted to analyze the clinical data of the 254 elderly women with hip fracture who had been surgically treated at Department of Orthopaedics and Traumatology, Shunyi District Hospital between December 2018 and December 2019. Their average age was (79.3±7.7) years. There were 128 femoral neck fractures and 126 intertrochanteric fractures. CT images of their proximal femurs on the healthy side were analyzed using quantitative CT Pro software to assess the BMDs at the femoral neck, greater trochanter, intertrochanteric region, and total hip. The primary endpoint was all-cause mortality during follow-up. The patients were classified into a death group and a censored group (survivors and those lost to follow-up). The secondary outcome was recovery of pre-fracture ambulation. Multivariable Cox proportional hazards regression was performed to evaluate the association between regional hip BMD and mortality risk.Results:Of the patients, 236 obtained a follow-up of 36.9 (32.7, 42.6) months and 18 were lost to the follow-up. A total of 28.3% (72/254) of the patients died within 3 years after surgery. The overall hip BMD [(0.510 9±0.094 3) g/cm 2], the greater trochanter BMD [(0.351 0±0.079 6) g/cm 2], and the intertrochanteric BMD[(0.629 5±0.116 9) g/cm 2] in the death group were significantly lower than those in the censored group [(0.565 8±0.104 1) g/cm 2, (0.398 6±0.092 1) g/cm 2, and (0.685 6±0.126 6) g/cm 2]( P<0.05). The multivariate Cox regression analysis showed that a lower BMD at all hip sites measured was significantly associated with a higher mortality risk before adjustments ( P<0.05), but after confounding variables were adjusted, only the greater trochanter BMD ( HR=1.789, 95% CI: 1.035 to 3.092, P=0.037) and the intertrochanteric BMD ( HR=1.758, 95% CI: 1.018 to 3.037, P=0.043) were significantly associated with a higher mortality risk. Furthermore, follow-ups showed that 54 patients (56.3%, 54/96) in the high trochanter BMD group regained their pre-fracture ambulatory status, significantly more than the 22 patients in the low BMD group (32.4%, 22/68), showing an increased odds of ambulation recovery ( OR=2.688, 95% CI: 1.405 to 5.143, P=0.003). Conclusion:In elderly women with hip fracture, quantitative CT-derived measurement of the hip BMD, particularly in the trochanteric region, can serve as an early warning indicator of all-cause mortality after hip fracture surgery.

Objective To explore the protective effect of 7,8-dihydroxyflavone(7,8-DHF)on the retina of diabetic rats and its mechanism.Methods A total of 18 SPF-grade male Sprague-Dawley(SD)rats were selected and randomly divided into three groups:the normal group,the model group,and the experimental group,with six rats in each group.Rats in the normal group were fed with a normal diet,while those in the remaining two groups were fed with a high-fat emulsion through oral gavage continuously for 2 weeks to establish a diabetes model.Rats in the experimental group were provided with 7,8-DHF(5 mg?kg-1)by continuous intraperitoneal injection,while those in the normal and model groups were provided with an equal volume of normal saline.The rats in all groups received intervention once a day for 2 weeks.The changes in the body mass and fasting blood glucose(FBG)were observed before and after modeling.Besides,the changes in the retina of rats in each group were observed by fundus fluorescence angiography(FFA)after 2 weeks.Moreo-ver,the changes and apoptosis of retinal neuronal cells were detected by hematoxylin and eosin(HE)staining,CD31 im-munofluorescence,and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assays.Results After 2 weeks of continuous intervention,compared with the normal group,the body mass of rats in the model and experimental groups decreased(both P＜0.05),and the FBG increased significantly(both P＜0.05);compared with the model group,the experimental group showed an increase in the body mass(P＜0.05)and a decrease in the FBG(P＜0.05).The fundus photography and FFA of rats in the three groups did not reveal any fundus features of diabetic retinopathy.The HE staining results showed that the retina of rats in the normal and experimental groups was structurally intact,with neatly arranged cells and uniform thickness;the retinal structure of rats in the model group remained clear.However,the thickness of the inner layers of the retina of rats in the model group was thinner compared with the normal and experimental groups,exhibi-ting significant differences(both P＜0.05).The CD31 immunofluorescence assay results indicated that the CD31 immuno-fluorescence intensity values of rats in the three groups were roughly comparable,without significant differences(all P＞0.05).The TUNEL assay results suggested that the apoptosis of retinal neurons increased in rats in the model group com-pared with the normal group,exhibiting significant differences(P＜0.001);compared with the model group,the apoptosis of retinal neurons of rats in the experimental group decreased significantly,displaying significant differences(P＜0.001).Conclusion The apoptosis of retinal neurons in diabetic rats may precede vascular endothelial cell injury.7,8-DHF can improve the body mass,decrease the blood glucose level,and protect the retinal neurons in diabetic rats.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

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 investigate the association between quantitative CT-derived hip bone mineral density (BMD) and all-cause mortality in elderly women after hip fracture surgery.Methods:A retrospective study was conducted to analyze the clinical data of the 254 elderly women with hip fracture who had been surgically treated at Department of Orthopaedics and Traumatology, Shunyi District Hospital between December 2018 and December 2019. Their average age was (79.3±7.7) years. There were 128 femoral neck fractures and 126 intertrochanteric fractures. CT images of their proximal femurs on the healthy side were analyzed using quantitative CT Pro software to assess the BMDs at the femoral neck, greater trochanter, intertrochanteric region, and total hip. The primary endpoint was all-cause mortality during follow-up. The patients were classified into a death group and a censored group (survivors and those lost to follow-up). The secondary outcome was recovery of pre-fracture ambulation. Multivariable Cox proportional hazards regression was performed to evaluate the association between regional hip BMD and mortality risk.Results:Of the patients, 236 obtained a follow-up of 36.9 (32.7, 42.6) months and 18 were lost to the follow-up. A total of 28.3% (72/254) of the patients died within 3 years after surgery. The overall hip BMD [(0.510 9±0.094 3) g/cm 2], the greater trochanter BMD [(0.351 0±0.079 6) g/cm 2], and the intertrochanteric BMD[(0.629 5±0.116 9) g/cm 2] in the death group were significantly lower than those in the censored group [(0.565 8±0.104 1) g/cm 2, (0.398 6±0.092 1) g/cm 2, and (0.685 6±0.126 6) g/cm 2]( P<0.05). The multivariate Cox regression analysis showed that a lower BMD at all hip sites measured was significantly associated with a higher mortality risk before adjustments ( P<0.05), but after confounding variables were adjusted, only the greater trochanter BMD ( HR=1.789, 95% CI: 1.035 to 3.092, P=0.037) and the intertrochanteric BMD ( HR=1.758, 95% CI: 1.018 to 3.037, P=0.043) were significantly associated with a higher mortality risk. Furthermore, follow-ups showed that 54 patients (56.3%, 54/96) in the high trochanter BMD group regained their pre-fracture ambulatory status, significantly more than the 22 patients in the low BMD group (32.4%, 22/68), showing an increased odds of ambulation recovery ( OR=2.688, 95% CI: 1.405 to 5.143, P=0.003). Conclusion:In elderly women with hip fracture, quantitative CT-derived measurement of the hip BMD, particularly in the trochanteric region, can serve as an early warning indicator of all-cause mortality after hip fracture surgery.

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≥0) and low-area group ( Z<0), and high-density group ( Z≥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.