Prediction of internal fixation failure of femoral trochanteric fracture by external wall morphology / 中国骨伤

OBJECTIVE@#To investigate the relationship between the shape of the lateral wall and the early failure of internal fixation in the fracture of the femoral trochanteric region(FFT).@*METHODS@#Total 295 patients with femoral trochanteric fracture underwent internal fixation from January 2015 to January 2020 were selected. The patients were divided into two groups according to whether there was early internal fixation failure after surgery, 19 patients in the failure group and 276 patients in the normal group. Gender, affected side, age, AO classification, body mass index(BMI), preoperative hemoglobin, X-ray measurement of lower lateral wall thickness, preoperative internal diseases, intraoperative blood loss, postoperative tip apex distance(TAD), postoperative neck shaft angle, operation time and other data were compared between two groups. The shape of the lateral wall was compared between two groups, and the correlation between the shape of the lateral wall and the early internal fixation failure of femoral trochanteric fracture was analyzed.@*RESULTS@#All patients were followed up for more than 1 year. There was no significant difference between two groups in terms of intraoperative blood loss, operation time, postoperative TAD, and postoperative neck shaft angle(P>0.05). At the latest follow-up, the visual anaglue scale (VAS) of the failure group was higher than that of the normal group(P<0.01), and the Harris score of the failure group was lower than that of normal group(P<0.05). The receiver operator characteristic (ROC) curve between shape of lateral wall and failure of early internal fixation of femoral trochanteric fracture was drawn. The critical value of the midpoint lateral wall thickness was 16.5 mm, and the area under the ROC curve was 0.845;The critical value of average sidewall thickness was 16.5 mm, and the area under ROC curve was 0.838;The critical value of the axial area of the sidewall was 7.5 mm, and the area under the ROC curve was 0.826.@*CONCLUSION@#The shape of the lateral femoral wall measured by CT could be used as a predictive factor for the early failure of internal fixation of femoral trochanteric fractures. For patients at risk, more reasonable surgical plans and postoperative preventive measures should be developed.

Measurement of the maximum corridor parameters of infra acetabular screw and evaluation of the feasibility of screw insertion by digital analysis / 中国骨伤

OBJECTIVE@#To measure the maximum corridor parameters of the infra acetabular screw and evaluate the feasibility of screw insertion through digital analysis of the acetabular structure.@*METHODS@#The pelvic CT data of 100 patients who received plain pelvic CT scan from April 2013 to June 2015 were retrospectively analyzed. There were 50 males, aged 20 to 84 years, with an average age of (48.42±17.48) years, and 50 females, aged 18 to 87 years, with an average age of (55.02±19.54) years. Patients with acetabular fractures, hip dysplasia, and metal implants in the acetabulum were excluded. Import CT data into Mimics software in DICOM format to generate a three-dimensional model, and find the axialprojection of the infra-acetabular corridor in the middle of the pubis ramus in the inlet view. A virtual screw was placed in the infra-acetabular space and measure the parameters including the diameter and the length of the maximum corridor, the distance from the insertion point to the pubic symphysis, to the anterosuperior iliac spine and to the medial edge of the pelvis. Then import the pelvic model into 3- matic software, establish the pelvic model anterior pelvic plane and median sagittal plane, and measure the angle between the screw axis and the two planes. A minimum corridor diameter of at least 5 mm was defined as a cutoff for placing a 3.5 mm screw, and calculate the screw insertion rate.@*RESULTS@#In 100 cases, 49% of patients had a infra acetabular corridor with a diameter ≥5 mm, and the rate of screw placement in men was significantly higher than that in women. The average diameter of the maximum corridor of infra-acetabular screw was (4.86±1.72) mm, the average length was (94.04±8.29) mm, the average distance from the insertion point to the pubic symphysis was (60.92±4.84) mm, to the anterosuperior iliac spine was (85.15± 6.85) mm, and to the medial edge of the pelvis was (6.12±3.32) mm. The mean angle between the axis of the screw and the median sagittal plane was (-1.38±4.74)°, and the mean angle between the axis of the screw and the anterior pelvic plane was (56.77±7.93)°. There are significant differences between male and female measured parameters, except for the angle between the screw axis and the anterior pelvic plane. There was no statistically significant difference in the maximum corridor parameters of infra-acetabular screw on both sides of the pelvis.@*CONCLUSION@#This study shows that the insertion rate of infra-acetabular screws is low in local patients, and the feasibility of screw insertion should be fully evaluated before surgery.