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 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 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 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 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.

Objective:To compare the long-term clinical outcomes between cannulated screw internal fixation for stable femoral neck fractures and arthroplasty for unstable ones in the elderly patients.Methods:A retrospective study was conducted to analyze the 542 patients with femoral neck fracture who had been admitted to Department of Orthopedics and Traumatology, Beijing Jishuitan Hospital, Capital Medical University from May 2015 to April 2017. The 542 patients were divided into 2 groups based on fracture stability and treatment method. In the stable group (Garden type Ⅰ, type Ⅱ, and abduction compression type) of 121 cases who underwent cannulated screw internal fixation, there were 28 males and 93 females with a mean age of (77.6±8.1) years, and 20 cases of type Ⅰ, 101 cases of type Ⅱ, and 34 cases of abduction compression type by the Garden classification. In the unstable group (Garden type Ⅲ, type Ⅳ, and type Ⅱ with a posterior tilt angle >20°) of 421 cases who underwent arthroplasty, there were 130 males and 291 females with a mean age of (78.7 ± 6.9) years, and 14 cases of type Ⅱ, 403 cases of type Ⅲ, and 4 cases of type Ⅳ by the Garden classification. The postoperative mortality, reoperation rate, and mobility at the last follow-up were compared between the 2 groups.Results:There were no statistically significant differences in the baseline characteristics, except for serum albumin concentration and peripheral white blood cell count at admission, between the 2 groups, indicating comparability ( P>0.05). The hospital stay in the stable group [5.0 (4.0, 6.0)d] was significantly shorter than that in the unstable group [6.0 (5.0, 8.0)d], and the follow-up time for the stable group [54.4 (49.3, 58.7) months] significantly longer than that for the unstable group [52.2 (46.0, 59.3) months] ( P<0.05). A total of 158 patients (45 cases in the stable group and 113 cases in the unstable group) were lost to the last follow-up. At the last follow-up, the mortality in the stable group (18.4%, 14/76) was significantly lower than that in the unstable group (31.5%, 97/308), the reoperation rate in the former (15.8%, 12/76) significantly higher than that in the latter (3.6%, 11/308), and the capability of daily activities in the former (by the fracture mobility scoring: level 1 in 35 cases, level 2 in 13 cases, level 3 in 3 cases, level 4 in 2 cases, and level 5 in 1 case) significantly better than that in the latter (level 1 in 99 cases, level 2 in 47 cases, level 3 in 24 cases, level 4 in 22 cases, and level 5 in 5 cases) (all P<0.05). Conclusion:Compared with the arthroplasty for unstable femoral neck fractures, cannulated screw internal fixation for stable femoral neck fractures leads to a lower long-term mortality and a better capability of daily activities, but a significantly higher reoperation rate.

ObjectiveTo evaluate the efficacy and safety of a perioperative rehabilitation clinical pathway of acetabular fracture in light of orthopedics rehabilitation team approach. MethodsA prospective randomized control trial was conducted in 82 patients with acetabular fractures who had been admitted from the Emergency Department of Orthopaedic Trauma, Beijing Jishuitan Hospital from June, 2019 to January, 2021. The patients were randomly divided into control group (n = 41) and intervention group (n = 41). The control group was managed routinely, while the intervention group received the rehabilitation clinical pathway, for 24 weeks. The Visual Analogue Score (VAS) of pain, the Barthel Index (BI) and Majeed Pelvic Score were compared. ResultsFinally, 76 patients completed the trial. There was no statistical difference in VAS score between two groups in all periods (|Z| < 1.926, P > 0.05). The BI score was higher in the intervention group than in the control group at discharge, two weeks, six weeks and twelve weeks after operation (|Z| > 2.121, P < 0.05); and no significant difference was found before operation and 24 weeks after operation (|Z| < 1.862, P > 0.05). Majeed Pelvic Score was higher in the intervention group than in the control group two weeks, six weeks, twelve weeks and 24 weeks after operation (|Z| > 2.428, P < 0.05). Six, twelve and 24 weeks after operation, the excellent rate of Majeed Pelvic Score was higher in the intervention group than in the control group (χ² > 6.136, P < 0.05). ConclusionIn comparison with traditional protocol in acetabular fracture, the perioperative rehabilitation clinical pathway was proved effective and of great safety in the light of the integration of orthopedics and rehabilitation mode for improving the function and activities of daily living of patients.

Objective:To compare the short-term efficacy between femoral neck system (FNS) and cannulated compression screws (CCS) in the treatment of femoral neck fractures in young and middle-aged patients.Methods:A retrospective study was performed of the 29 young and middle-aged patients with femoral neck fracture who had been treated with FNS at Department of Orthopaedics and Traumatology, Beijing Jishuitan Hospital from January 2020 to December 2020. A control group of another 29 patients with femoral neck fracture was selected who had been treated with CCS but matched in gender, age, and body mass index. In the CCS group, there were 14 males and 15 females with an age of (48.2±12.3) years; in the FNS group, there were 14 males and 15 females with an age of (48.2±12.0) years. The fracture reduction quality, operation time, intraoperative blood loss, and femoral neck shortening, hip joint function, Barthel index and health survey 12-item short form (SF-12) score at the last follow-up and complications during follow-up were compared between the 2 groups.Results:No significant difference was found in the preoperative general data or follow-up time between the 2 groups, showing comparability ( P>0.05). The intraoperative blood loss in the CCS group [20 (10, 50) mL] was significantly less than that in the FNS group [50 (20, 50) mL], and the femoral neck shortening at the last follow-up in the CCS group (grade 1 in 5 cases; grade 2 in 18 cases and grade 3 in 6 cases) was significantly worse than that in the FNS group (grade 1 in 21 cases, grade 2 in 6 cases and grade 3 in 2 cases) ( P<0.05). No significant difference was found regarding fracture reduction quality, operation time, complications during follow-up, or Merle D'Aubigne Postel score, Barthel index or SF-12 score at the last follow-up ( P>0.05). Conclusions:In the treatment of femoral neck fractures in young and middle-aged patients, both FNS and CCS are good options for internal fixation. However, FNS can reduce the severity of femoral neck shortening and maintain the length of femoral neck better than CCS.

Objective:To evaluate the efficacy and safety of perioperative rehabilitation approaches based on the concept of Enhanced Recovery After Surgery (ERAS) for pelvic fractures.Methods:A prospective randomized control trial was conducted to include 114 emergency patients who had been admitted to Department of Orthopaedic Trauma, Beijing Jishuitan Hospital for surgical treatment of pelvic fractures from June 2019 to December 2020. Of them, 57 were assigned into an intervention group according to a random digits table. They were 42 males and 15 females, aged from 18 to 77 years and subjected to management of pelvic fractures with tentative perioperative ERAS approaches which were adjusted at different stages. The other random 57 patients were assigned into a control group. They were 40 males and 17 females, aged from 17 to 70 years and subjected to management of pelvic fractures with conventional rehabilitation approaches which included postoperative in-hospital consultation and guidance by rehabilitation physicians. The 2 groups were compared in terms of Majeed pelvis scores and Barthel indexes at postoperative 2, 6, 12 and 24 weeks, and visual analogue scale (VAS) pain scores and SF36 scores at postoperative 12 and 24 weeks.Results:A total of 105 patients (55 in the intervention group and 50 in the control group) were completely followed up for 151 to 254 d (mean, 177 d). The 2 groups were comparable due to no significant difference between them in the preoperative general data ( P>0.05). The Majeed scores (44±13, 67±16, 86±14 and 98±7) and Barthel indexes (57±13, 79±16, 95±8 and 100±2) at postoperative 2, 6, 12 and 24 weeks in the intervention group were significantly higher than those in the control group [(35±16, 51±16, 73±14 and 91±12) and (45±19, 67±18, 86±12 and 98±4)] (all P<0.05). At postoperative 12 and 24 weeks, the SF-36 scores (129±15 and 141±6) in the intervention group were significantly higher than those in the control group (114±15 and 131±12) ( P<0.05). There was no significant difference in the pain degree between the 2 groups ( P>0.05). Conclusion:In management of pelvic fractures, compared with conventional perioperative rehabilitation approaches, the perioperative ERAS rehabilitation approaches may improve early functional outcomes and thus help the patients restore their activities of daily living earlier.

Objective: To investigate the clinical characteristics and risk factors for pulmonary infection in elderly patients with hip fracture after the treatment through a model of orthopedic-geriatric co-care, in order to provide prevention and control strategies. Methods: Clinical data and laboratory results of elderly patients with hip fractures admitted into our hospital from January 2016 to May 2016 were collected.The differences in treatment outcome and adverse reactions were retrospectively compared between the two groups of patients with versus without pulmonary infection, and univariate and multivariate analysis of lung infection were performed. Results: Of 207 patients, 43 were infected with pneumonia and 164 were not.The proportion of patients with the time interval<48 h from admission to surgery was 48.6%(86/177), and the time interval<1 week from admission to surgery was 98.9%(175/177). The average length of hospital stay was(7.9±3.5)days.There was no significant difference in the time interval from admission to surgery, the time spent on surgery, length of hospital stay, surgical procedure and inflammatory indicators between the pneumonia and non-pneumonia groups.Univariate analysis showed that advanced age, multiple primary diseases, primary lung diseases, chronic respiratory failure, cerebrovascular disease, sequelae of cerebrovascular disease, immune system disease or long-term oral hormone therapy and preoperative anemia were risk factors for pulmonary infection in elderly patients with hip fracture(P<0.05 or<0.01). Multivariate regression analysis showed that advanced age(OR=1.239, 95%CI: 1.016~1.595, P=0.051), preoperative anemia(OR=2.491, 95%CI: 1.148~5.403, P=0.021), sequelae of cerebrovascular disease(OR=3.987, 95%CI: 1.354~11.741, P=0.012), primary lung diseases(OR=4.404, 95%CI: 1.800~11.078, P=0.001)and immune system diseases(OR=17.166, 95%CI: 1.750~168.409, P=0.015)were independent risk factors for pulmonary infection in elderly patients with hip fracture. Conclusions The orthopedic-geriatric co-care model seems to be in favour of controlling the progress of pulmonary infection in elderly patients with hip fracture, and to shorten waiting time before surgery and length of hospital stay.However, advanced age and chronic diseases are unpreventable risk factors for pulmonary infection in elderly patients with hip fractures.Clinicians should pay attention to the high-risk population and take prevention and control strategies to prevent the occurrence and development of lung infections.