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Objective@#To study the influencing factors of fracture nonunion after intramedullary nailing for subtrochanteric fracture and construct a risk assessment model.@*Methods@#A retrospective analysis was performed on 251 patients with intramedullary nail fractures of the femoral subtrochanteric fracture from February 2006 to January 2018. According to the different treatment time, the 251 patients included in this study were divided into the modeling group and the verification group. In the modeling group, postoperative fracture nonunion rate, general data, fracture related factors, surgical reduction related factors, mechanical and biological factors were calculated, and the influencing factors of fracture nonunion were screened by univariate analysis. Indicators with statistical differences in univariate analysis were analyzed using Logistic regression model for multivariate analysis to build the risk assessment model. The influencing factors were re-evaluated through the verification group, and the differentiation and calibration of the model were evaluated.@*Results@#Fracture nonunion occurred in 34 of 149 patients in the modeling group. Among the 13 potential influencing factors, univariate analysis and logistic regression analysis showed that postoperative hip varus, intramedullary nail fixation failure and complete open reduction were the risk factors of fracture nonunion. Postoperative reduction of medial cortex was a protective factor for fracture nonunion, and a regression equation was established. Based on the logistic regression model, the Nomogram diagram was drawn. In the verification group, fracture nonunion occurred in 24 of 149 patients. The area under the ROC curve was AUC=0.883>0.7, indicating that there was a moderate differentiation to evaluate the occurrence of fracture nonunion after operation. The goodness of fit test: the H-L test (χ2=2.921, P=0.712) showed that the model had a good calibration.@*Conclusion@#The risk factors of fracture nonunion were hip varus, failure of intramedullary nail fixation and complete open reduction after intramedullary nailing of subtrochanteric fracture, and postoperative reduction of medial cortex was the protective factor. The risk assessment model has moderate differentiation and good calibration, which can provide reference for the risk assessment of fracture nonunion after subtrochanteric fracture operation.
RÉSUMÉ
Objective To study the influencing factors of fracture nonunion after intramedullary nailing for subtrochanteric fracture and construct a risk assessment model.Methods A retrospective analysis was performed on 251 patients with intramedullary nail fractures of the femoral subtrochanteric fracture from February 2006 to January 2018.According to the different treatment time,the 251 patients included in this study were divided into the modeling group and the verification group.In the modeling group,postoperative fracture nonunion rate,general data,fracture related factors,surgical reduction related factors,mechanical and biological factors were calculated,and the influencing factors of fracture nonunion were screened by univariate analysis.Indicators with statistical differences in univariate analysis were analyzed using Logistic regression model for multivariate analysis to build the risk assessment model.The influencing factors were re-evaluated through the verification group,and the differentiation and calibration of the model were evaluated.Results Fracture nonunion occurred in 34 of 149 patients in the modeling group.Among the 13 potential influencing factors,univariate analysis and logistic regression analysis showed that postoperative hip varus,intramedullary nail fixation failure and complete open reduction were the risk factors of fracture nonunion.Postoperative reduction of medial cortex was a protective factor for fracture nonunion,and a regression equation was established.Based on the logistic regression model,the Nomogram diagram was drawn.In the verification group,fracture nonunion occurred in 24 of 149 patients.The area under the ROC curve was AUC=0.883 ＞ 0.7,indicating that there was a moderate differentiation to evaluate the occurrence of fracture nonunion after operation.The goodness of fit test:the H-L test (x2=2.921,P=0.712) showed that the model had a good calibration.Conclusion The risk factors of fracture nonunion were hip varus,failure of intramedullary nail fixation and complete open reduction after intramedullary nailing of subtrochanteric fracture,and postoperative reduction of medial cortex was the protective factor.The risk assessment model has moderate differentiation and good calibration,which can provide reference for the risk assessment of fracture nonunion after subtrochanteric fracture operation.
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Objective To explore the advantages and security of orthopaedic TiRobot used to assist internal fixation with sacroiliac lag screws.Methods From December 2015 to August 2017,11 patients with fracture of pelvic posterior ring or sacroiliac separation were treated by internal fixation with sacroiliac lag screws assisted by an orthopaedic TiRobot at Department of Orthopaedic Surgery,Affiliated Hospital to Chengdu University.They were 7 men and 4 women,aged from 23 to 61 years (average,42.5 years).According to AO classification,there were one case of type B1.2,one case of type B2.2,6 cases of type C1.2,2 cases of type C1.3 and one case of type C2.3.The number of sacroiliac lag screws inserted,time for planning insertion approaches,fluoroscopy frequency,fluoroscopy time,exposure time of C-arm X-ray,operation time,blood loss and reduction quality were documented.Results The 11 patients were followed up for 5 to 22 months (average,9.5 months).A total of 15 sacroiliac screws were inserted.In the operations,time for planning insertion approaches averaged 8.5 minutes (from 9 to 25 minutes),fluoroscopy frequency 8.5 times (from 4 to 15 times),fluoroscopy time 5.5 minutes (from 3.2 to 6.5 minutes),exposure time of C-arm X-ray machine 5.8 seconds (from 2.4 to 16.3 seconds),operation time 34.5 minutes (from 25 to 45 minutes),and blood loss 35 mL (from 10 to 80 mL).All the screw positions were satisfactory,with no penetration into the sacral canal,sacral foramen or bone cortex.No postoperative neurovascular injury happened.All the incisions primarily healed.All the fractures united well after 4 to 7 months (average,5.6 months),without any screw loosening.By the Matta scoring for fracture reduction,9 cases were excellent,one was good and one fair.By the Majeed functional scoring for pelvic fractures,8 cases were rated as excellent and 3 as good at the last follow-up.Conclusion Orthopaedic TiRobots can be used to assist internal fixation with sacroiliac lag screws in the treatment of pelvic posterior ring injuries,with advantages of limited invasion,time,hemorrhage,and high safety and accuracy as well.
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Objective To compare intramedullary nail (IN) and dynamic hip screw (DHS) regarding their effects on hip abduction following fixation of intertrochanteric fractures.Methods From January 2008 to December 2015,310 patients with intertrochanteric firacture were treated at our department.They were divided into 2 groups depending on the manner of treatment.198 patients (71 males and 127 females) were subjected to intramedullary nailing,with an average age of 74.7 ± 5.6 years;there were 50 cases of 31-A 1,134 ones of 3 1-A2 and 14 ones of 3 1-A3 according to the AO classification.112 patients (35 males and 77 females) were subjected to dynamic hip screwing,with an average age of 74.1 ± 6.7 years;there were 24 cases of 31-A1,78 ones of 31-A2 and 10 ones of 31-A3.The 2 groups were compared in terms of time for weight-bearing ambulation and stand on one leg,gait,pelvic tilt,range of hip active abduction,muscle strength of the abductor and hip function at the final follow-up.Results Of this series,284 patients were followed up for 1.5 to 8.5 years (average,3.6 years) and 26 patients died.The IN group achieved significantly better outcomes in terms of time for weight-bearing ambulation (37.6 ±4.9 d),time for stand on one leg (60.1 ± 9.5 d),cases of normal gait and normal pelvic tilt (171 and 179),muscle strength of the abductor (62.3 ±4.4 N · m),and range of hip active abduction than the DHS group (53.0 ±8.4 d;71.0 ± 12.0 d;67 and 85;56.6 ± 3.3 N · m,respectively) (P ＜ 0.05).There was no significant difference between the 2 groups in the hip function at the final follow-up(91.4％ versus 84.5％ in the excellent and good rate)(P ＞ 0.05).Conclusion Compared with dynamic hip screwing,intramedullary nailing has a limited effect on hip abduction so that the patients may benefit from quicker functional recovery and faster improvement in quality of life.