Objective:To investigate the diagnosis and treatment of pre-excitation syndrome in civil aircrews, and to provide data for aeromedical assessment of this disease.Methods:The clinical data of 20 civil aircrews was retrospectively analyzed who were diagnosed with pre-excitation syndrome during the annual health checkup at a civil aviation physical examination institution between April 2022 and June 2023. The pathogenesis, electrocardiographic manifestations, diagnosis and treatment, and results of aeromedical assessment of pre-excitation syndrome were summarized.Results:Among the 20 civil aircrews detected with pre-excitation syndrome, 1 case showed apical hypertrophic cardiomyopathy on echocardiography, which was identified as unqualified for flight missions by aeromedical assessment. Supraventricular tachycardia or ventricular tachycardia occurred in 3 cases, 2 of whom were determined as qualified after specially-permitted assessment, but their duration of flight and duties as a captain were restricted. One security guard was determined as qualified. One aircrew and one security guard developed symptoms of palpitation caused by paroxysmal supraventricular tachycardia, but were identified as qualified after radiofrequency ablation. The other 14 aircrews had no symptoms of palpitation, nor was arrhythmia revealed by Holter. Aeromedical assessment concluded that they were eligible for flight.Conclusions:The aeromedical assessment of pre-excitation syndrome among civil aircrews should be individualized and based on 24 h Holter findings, treadmill exercise test, echocardiography, cardiac electrophysiology and other examinations.

Objective:To evaluate the efficacy of reduction robot system combined with minimally invasive, microenvironmental protection, micro-stress shielding fixator (short for "3M fixator") for Sanders types II and III calcaneal fractures.Methods:A retrospective case series study was conducted to analyze the clinical data of 26 patients (26 feet) with calcaneal fractures admitted to Fourth Affiliated Central Hospital of Tianjin Medical University from June 2022 to June 2024, including 21 males and 5 females, aged 27-69 years [(46.5±2.5)years]. Among them, 10 patients had fractures in the left foot and 16 in the right. According to the Sanders classification, the fractures were classified as type II in 16 patients and type III in 10. All the patients were treated with the close reduction with reduction robot system combined with 3M fixator in a minimally invasive procedure. The surgical waiting time, operative duration, and fracture healing time were recorded. The length, width and height of the calcaneus, B?hler′s angle and Gissane′s angle were compared before operation and at 1, 3 months after operation. The visual analogue scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score before operation and at 1, 3 months after operation and at the last follow-up were detected. The postoperative complications were recorded.Results:All the patients were followed up for 6-12 months [(9.7±1.1)months]. The surgical waiting time was 1-4 days [(2.0±0.8)days]. The operative duration was 36-66 minutes [(53.2±9.5)minutes]. All the fractures achieved primary union with a healing period of 3-4 months [(3.2±0.4)months]. At 1, 3 months after operation, the length of the calcaneus [(83.3±3.7)mm and (83.6±3.6)mm], width of the calcaneus [(44.3±5.8)mm and (44.3±5.7)mm], height of the calcaneus [(50.1±3.8)mm and (50.3±3.6)mm], B?hler′s angle [(29.8±2.9)° and (29.8±3.0)°], and Gissane angle [(121.1±6.7)° and (123.9±5.9)°] were significantly improved compared with those before operation [(79.3±4.5)mm, (53.6±4.1)mm, (46.2±3.7)mm, (18.9±3.8)°, (109.0±7.5)°, respectively] ( P<0.05), with no significant differences between those indicators at 1, 3 months after operation ( P>0.05). The VAS scores were (3.2±0.6)points, (1.9±0.5)points, and (1.6±0.3)points at 1, 3 months after operation and at the last follow-up, which were lower than (7.1±0.5)points preoperatively and decreased with the prolongation of follow-up time ( P<0.05). The AOFAS scores were (73.5±6.9)points, (90.1±4.3)points, and (92.0±3.6)points, which were higher than (32.0±4.6)points preoperatively and increased with the follow-up time ( P<0.05). One patient had lateral calcaneal pain after operation, and was alleviated after rehabilitation. No complications such as infection or nonunion were found after operation. Conclusion:The reduction robot system combined with 3M fixator for Sanders types II and III calcaneal fractures demonstrates significant clinical advantages, such as reduced surgical waiting time and operative duration, promoted fracture healing, early alleviated pain, enhanced ankle joint functional recovery, and decreased complication occurrence.

Objective:To evaluate the efficacy of reduction robot system combined with minimally invasive, microenvironmental protection, micro-stress shielding fixator (short for "3M fixator") for Sanders types II and III calcaneal fractures.Methods:A retrospective case series study was conducted to analyze the clinical data of 26 patients (26 feet) with calcaneal fractures admitted to Fourth Affiliated Central Hospital of Tianjin Medical University from June 2022 to June 2024, including 21 males and 5 females, aged 27-69 years [(46.5±2.5)years]. Among them, 10 patients had fractures in the left foot and 16 in the right. According to the Sanders classification, the fractures were classified as type II in 16 patients and type III in 10. All the patients were treated with the close reduction with reduction robot system combined with 3M fixator in a minimally invasive procedure. The surgical waiting time, operative duration, and fracture healing time were recorded. The length, width and height of the calcaneus, B?hler′s angle and Gissane′s angle were compared before operation and at 1, 3 months after operation. The visual analogue scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score before operation and at 1, 3 months after operation and at the last follow-up were detected. The postoperative complications were recorded.Results:All the patients were followed up for 6-12 months [(9.7±1.1)months]. The surgical waiting time was 1-4 days [(2.0±0.8)days]. The operative duration was 36-66 minutes [(53.2±9.5)minutes]. All the fractures achieved primary union with a healing period of 3-4 months [(3.2±0.4)months]. At 1, 3 months after operation, the length of the calcaneus [(83.3±3.7)mm and (83.6±3.6)mm], width of the calcaneus [(44.3±5.8)mm and (44.3±5.7)mm], height of the calcaneus [(50.1±3.8)mm and (50.3±3.6)mm], B?hler′s angle [(29.8±2.9)° and (29.8±3.0)°], and Gissane angle [(121.1±6.7)° and (123.9±5.9)°] were significantly improved compared with those before operation [(79.3±4.5)mm, (53.6±4.1)mm, (46.2±3.7)mm, (18.9±3.8)°, (109.0±7.5)°, respectively] ( P<0.05), with no significant differences between those indicators at 1, 3 months after operation ( P>0.05). The VAS scores were (3.2±0.6)points, (1.9±0.5)points, and (1.6±0.3)points at 1, 3 months after operation and at the last follow-up, which were lower than (7.1±0.5)points preoperatively and decreased with the prolongation of follow-up time ( P<0.05). The AOFAS scores were (73.5±6.9)points, (90.1±4.3)points, and (92.0±3.6)points, which were higher than (32.0±4.6)points preoperatively and increased with the follow-up time ( P<0.05). One patient had lateral calcaneal pain after operation, and was alleviated after rehabilitation. No complications such as infection or nonunion were found after operation. Conclusion:The reduction robot system combined with 3M fixator for Sanders types II and III calcaneal fractures demonstrates significant clinical advantages, such as reduced surgical waiting time and operative duration, promoted fracture healing, early alleviated pain, enhanced ankle joint functional recovery, and decreased complication occurrence.

Objective:To investigate the diagnosis and treatment of pre-excitation syndrome in civil aircrews, and to provide data for aeromedical assessment of this disease.Methods:The clinical data of 20 civil aircrews was retrospectively analyzed who were diagnosed with pre-excitation syndrome during the annual health checkup at a civil aviation physical examination institution between April 2022 and June 2023. The pathogenesis, electrocardiographic manifestations, diagnosis and treatment, and results of aeromedical assessment of pre-excitation syndrome were summarized.Results:Among the 20 civil aircrews detected with pre-excitation syndrome, 1 case showed apical hypertrophic cardiomyopathy on echocardiography, which was identified as unqualified for flight missions by aeromedical assessment. Supraventricular tachycardia or ventricular tachycardia occurred in 3 cases, 2 of whom were determined as qualified after specially-permitted assessment, but their duration of flight and duties as a captain were restricted. One security guard was determined as qualified. One aircrew and one security guard developed symptoms of palpitation caused by paroxysmal supraventricular tachycardia, but were identified as qualified after radiofrequency ablation. The other 14 aircrews had no symptoms of palpitation, nor was arrhythmia revealed by Holter. Aeromedical assessment concluded that they were eligible for flight.Conclusions:The aeromedical assessment of pre-excitation syndrome among civil aircrews should be individualized and based on 24 h Holter findings, treadmill exercise test, echocardiography, cardiac electrophysiology and other examinations.

Objective:To explore the clinical effectiveness of a self-designed robot reduction system for femoral intertrochanteric fractures.Methods:A retrospective study was conducted to analyze the 57 patients with intertrochanteric fracture who had been treated at Department of Orthopedics, The Fourth Affiliated Central Hospital of Tianjin Medical University from June 2022 to February 2023. The patients were divided into a robot group (using the self-designed robot reduction system to assist intramedullary nailing) and a traction bed group (using a traction bed to assist intramedullary nailing) based on their fracture reduction method. The robot group: 31 patients, 11 males and 20 females, with an age of (78.7±9.3) years; 16 left and 15 right sides; 17 cases of type 31-A1, 12 cases of type 31-A2 and 2 cases of type 31-A3 by the AO/OTA classification. The traction bed group: 26 patients, 12 males and 14 females, with an age of (78.7±7.7) years; 13 left and 13 right sides; 16 cases of type 31-A1, 9 cases of type 31-A2 and 1 cases of type 31-A3 by the AO/OTA classification. The 2 groups were compared in terms of reduction and operation time, intraoperative blood loss, fluoroscopy frequency, reduction quality, and VAS and Harris score at preoperation, 1 week and 6 months postoperation.Results:The 2 groups were comparable due to insignificant differences in their preoperative general data ( P>0.05). The robot group was significantly better than the traction bed group in reduction time [(4.4±2.2) min versus (9.4±3.2) min], operation time [(29.0±13.5) min versus (49.3±13.3) min], intraoperative blood loss [(76.5±30.5) mL versus (115.0±38.4) mL], fluoroscopy frequency [(10.2±2.6) times versus (14.8±3.2) times], and good/excellent rate of reduction [80.6% (25/31) versus 50.0% (13/26)] ( P<0.05). All patients were followed up for (6.8±0.3) months. Respectively, the VAS scores at preoperation and 6 months postoperation was (6.2±1.3) and (2.4±0.8) points for the robot group, and (6.3±1.3) and (2.7±0.8) points for the traction bed group, showing no statistically significant differences between the 2 groups ( P>0.05). However, the VAS score was (3.3±1.2) points for the robotic group and (4.8±1.5) points for the traction bed group at 1 week postoperation, showing a statistically significant difference between the 2 groups ( P<0.001). Respectively, the Harris scores at preoperation and 6 months postoperation were (35.3±3.0) and (88.7±3.4) points for the robot group, and (35.6±2.9) and (87.2±3.5) points for the traction bed group, showing no statistically significant differences between the 2 groups ( P>0.05). However, the Harris score was (57.3±3.7) points for the robotic group and (46.7±2.8) points for the traction bed group at 1 week postoperation, showing a statistically significant difference between the 2 groups ( P<0.05). The patient satisfaction rates in the robot and traction bed groups were 96.8% (30/31) and 92.3% (24/26), respectively, showing no statistically significant difference ( P>0.05). Conclusion:Our self-designed robot reduction for femoral intertrochanteric fractures can effectively shorten reduction and operation time, reduce bleeding and fluoroscopy frequency, and enhance anatomical reduction.

Objective:To evaluate the effect of femoral stable interlocking intramedullary nail (FSIIN) and proximal femoral nail anti-rotation (PFNA) in the treatment of anterograde intertrochanteric fractures.Methods:From June 2015 to December 2020, 68 cases with surgically treated of femoral intertrochanteric fractures were included. Among them, there were 37 cases (17 males and 20 females) in proximal femoral nail antirotation (PFNA) group, and the age ranged from 48 to 78 years (62.9±7.1 years); 18 cases were on the left and 19 cases on the right; AO/OTA classification: 16 cases of A1 type and 21 cases of A2 type. And there were 31 cases (18 males and 13 females) in FSIIN group without distal locking, the age ranged from 47 to 84 years (62.4±8.6 years); 15 cases were on the left and 16 cases on the right; AO/OTA classification: 11 cases of A1 type and 20 cases of A2 type. Fracture fixation time, incision length and number, intraoperative blood loss, fracture healing time, visual analogue scale (VAS) and Harris scores at the last follow-up were compared between the two fixation methods.Results:Both groups were followed up, and the follow-up time was 15.3±3.9 months in the FSIIN group and 15.7±3.9 months in the PFNA group, and the difference was not statistically significant ( t=0.42, P=0.675). In FSIIN group, the fracture fixation time was 26.6±11.5 min, the total incision length was 7.6±1.8 cm, the intraoperative blood loss was 107.6±42.8 ml and the fracture healing time was 10.1±1.3 weeks. In PFNA group, the fracture fixation time was 40.3±10.8 min, the total incision length was 12.2±1.8 cm, the intraoperative blood loss was 209.4±52.0 ml and the fracture healing time was 16.3±1.6 weeks. In FSIIN group, the fracture fixation time ( t=3.46, P<0.001), total incision length ( t=2.39, P=0.020), intraoperative blood loss ( t=3.16, P<0.001), fracture healing time ( t=2.80, P<0.001) were all less than those in PFNA group, and the difference was statistically significant. The VAS score of FSIIN group was 1.4±0.5 points, and that of PFNA group was 1.6±0.6 points, and the difference was not statistically significant ( t=0.68, P=0.503). The Harris score was 84.5±2.2 in FSIIN group and 83.3±2.5 in PFNA group, and the difference was not statistically significant ( t=0.63, P=0.530). At the last follow-up, 29 patients in the FSIIN group were very satisfied with the operation, and 2 patients were satisfied with the operation, with a satisfaction rate of 100%. In PFNA group, 30 patients were very satisfied with the operation, 7 patients were satisfied with the operation, and the satisfaction rate was 100%. Conclusion:Compared with PFNA, micro-invasive and micro-stress shielding methodes of FSIIN in the fixation of anterograde intertrochanteric fractures is more minimally invasive, simple, time-saving, less bleeding, less risk, less pain, minimal stress shilding and enhanced recovery after surgery. The effect of treatment is similar in FSIIN and PFNA group.

Objective:To evaluate the efficacy of femoral stable interlocking intramedullary nail (FSIIN) in the treatment of anterograde intertrochanteric fractures.Methods:FSIIN was invented to treat femoral intertrochanteric fractures. From January 2005 to February 2019, 36 cases of anterograde intertrochanteric fractures were retrospectively analyzed. Among them, 29 cases were from the Fourth Central Hospital Affiliated to Nankai University and 7 cases were from the Second People's Hospital of Hulunbuir City. 15 cases (6 males and 9 females) were treated with FSIIN distal locking fixation(distal locking group). The average age was 68.53±10.82 years (range, 48-80 years old); According to AO/OTA classification, there were 7 cases of 31-A1 type and 8 cases of 31-A2 type. 21 cases (12 males and 9 females) were treated by FSIIN distal fixation non-locking (distal unlocking group). The average age was 67.86±11.70 years (range, 46-85 years). there were 9 cases of 31-A1 type and 12 cases of 31-A2 type. The operation time, intraoperative blood loss, fracture healing time, visual analogue scale (VAS) and Harris scores at the last follow-up were compared between the two fixation methods.Results:Both groups were followed up for 10-24 months, and the mean time in the lock group was 16.73±3.41 months. The mean time in the non-locking group was 16.10±3.36 months. In the locked group, the operation time was 43.47±2.39 min, the intraoperative blood loss was 149.33±44.96 ml, and the fracture healing time was 14.57±1.50 weeks. In the non-locking group, the operation time was 33.29±5.30 min, intraoperative blood loss was 97.62±38.46 ml, and fracture healing time was 10.16±1.20 weeks. The operation time of the non-locking group was shorter than the locking group ( t=6.930, P<0.001), intraoperative blood loss was decreased than the locking group ( t=3.708, P<0.001), fracture healing time was reduced than the locking group ( t=9.818, P<0.001). At the last follow-up, the VAS score of the locked group was 1.60±0.63 and the non-locked group was 1.81±1.08, which showed no significant difference( t=0.673, P=0.506). There was no significant difference in Harris score between the locked group 84.33±2.53 and the non-locked group 84.90±2.19( t=0.724, P=0.474). Eight weeks after the operation, the proximal inferior locking nail was withdrawn 1 cm in 1 case. The fracture healed without treatment. Conclusion:Both FSIIN distal locking and non-locking are effective methods for the treatment of femoral intertrochanteric fractures. Compared with the distal locking group, the non-locking group had more simpler operation, more minimally invasive, and enhanced recovery after surgery.

Objective:To evaluate the diagnosis of renal function impairment as the serum creatinine (Scr) level raised in pilots by determining the glomerular filtration rate (GFR) ( 99mTc-GFR) through diethylene triamine pentaacetic acid (DTPA) renal dynamic imaging standard method and to compare the accuracy of determining simply elevated Scr between the diagnosing of cystatin C (Cys C) and GFR evaluation for flying personnel. Methods:In this study, pilots and pilot cadets whose Scr level was diagnosed raised twice in the physical examinations at Civil Aviation Medical Center of Civil Aviation Administration of China during 2018-2019 were selected as subjects. The GFR was calculated by the evaluation equations of Cockcroft-Gault creatinine clearance (CG-CCr) and the modification of diet in renal disease (MDRD-GFR) upon the averaged Scr level. Blood Cys C and 99mTc-GFR were examined. According to the examination results, they were divided into 99mTc-GFR normal group ( 99mTc-GFR≥90 ml/min) and 99mTc-GFR reduced group ( 99mTc-GFR<90 ml/min). Results:A total of 95 cases were enrolled, all male with an average age of (35.27±10.32) years. There were 59 cases with renal function impairment, accounting for 62.1%. The correlation coefficients r of Scr, MDRD-GFR, Cys C, CG-CCr and total kidney 99mTc-GFR were 0.218, 0.535, 0.808, 0.857, respectively. There were statistically significant differences in MDRD-GFR, CG-CCr and Cys C between normal and reduced 99mTc-GFR groups ( P<0.01). Conclusion:The percentage of renal impairment in simple Scr raised pilots is 62.1%. Besides 99mTc-GFR, Cys C and CG-CCr have good diagnostic accuracy and can be used as a supplementary examination item for the patients with elevated Scr.

Objective:To evaluate the diagnosis of renal function impairment as the serum creatinine (Scr) level raised in pilots by determining the glomerular filtration rate (GFR) ( 99mTc-GFR) through diethylene triamine pentaacetic acid (DTPA) renal dynamic imaging standard method and to compare the accuracy of determining simply elevated Scr between the diagnosing of cystatin C (Cys C) and GFR evaluation for flying personnel. Methods:In this study, pilots and pilot cadets whose Scr level was diagnosed raised twice in the physical examinations at Civil Aviation Medical Center of Civil Aviation Administration of China during 2018-2019 were selected as subjects. The GFR was calculated by the evaluation equations of Cockcroft-Gault creatinine clearance (CG-CCr) and the modification of diet in renal disease (MDRD-GFR) upon the averaged Scr level. Blood Cys C and 99mTc-GFR were examined. According to the examination results, they were divided into 99mTc-GFR normal group ( 99mTc-GFR≥90 ml/min) and 99mTc-GFR reduced group ( 99mTc-GFR<90 ml/min). Results:A total of 95 cases were enrolled, all male with an average age of (35.27±10.32) years. There were 59 cases with renal function impairment, accounting for 62.1%. The correlation coefficients r of Scr, MDRD-GFR, Cys C, CG-CCr and total kidney 99mTc-GFR were 0.218, 0.535, 0.808, 0.857, respectively. There were statistically significant differences in MDRD-GFR, CG-CCr and Cys C between normal and reduced 99mTc-GFR groups ( P<0.01). Conclusion:The percentage of renal impairment in simple Scr raised pilots is 62.1%. Besides 99mTc-GFR, Cys C and CG-CCr have good diagnostic accuracy and can be used as a supplementary examination item for the patients with elevated Scr.

OBJECTIVE: To investigate the incidence and influencing factors of hypertension among civil aviation pilots. METHODS: A total of 1 169 civil aviation pilots in Northern China were selected into the study by the method of convenient sampling. Physical examination, laboratory test and questionnaire survey were conducted. RESULTS: The prevalence of hypertension in Northern China was 4.7%(55/1 169). Multivariate regression analysis showed that the relative risk factors ranking from high to low were, age over 30 years [odds ratio(OR)=6.81, 95% confidence interval(95%CI) 3.57-12.98)], total flight hours over 1 000 hours(OR=4.24, 95%CI 2.14-8.41), flight hours over 500 hours in the past year(OR=2.91, 95%CI 1.57-5.40), obesity(OR=2.50, 95%CI 1.08-5.81), fasting blood glucose(OR=2.24, 95%CI 1.21-4.13), and frequent long-distance flight(OR=2.38, 95%CI 1.24-4.58). These factors were the risk factors of hypertension in civil aviation pilots(P<0.05). CONCLUSION: Age, total flight hours, flight hours in the past year, obesity, fasting blood glucose, frequent long-distance flight are related to the prevalence of hypertension in civil aviation pilots.