[Morphological analysis of coronal femoral intertrochanteric fracture and its effect on reduction and internal fixation].

OBJECTIVE: To investigate the morphology of coronal femoral intertrochanteric fracture and its effect on reduction and internal fixation.
METHODS: The clinical and imaging data of 46 patients with femoral intertrochanteric fracture who met the selection criteria between August 2017 and October 2018 were reviewed. There were 15 males and 31 females; the age ranged from 62 to 91 years, with an average of 72.8 years. The causes of injury included walking falls in 35 cases, falling out of bed in 4 cases, and traffic accidents in 7 cases. The AO/Orthopaedic Trauma Association classification was type 31-A1 in 11 cases and type 31-A2 in 35 cases. All patients underwent closed reduction and internal fixation with intramedullary nails. During the operation, fracture reduction and fixation were performed according to the preoperative evaluation results. According to the patients' preoperative X-ray film and CT three-dimensional reconstruction images, the direction of the coronal fracture line of the femoral intertrochanter and the morphological characteristics of the fracture block were observed; and the coronal fracture discrimination analysis was carried out for the fractures of different AO/OTA types. The percentages of coronal femoral intertrochanteric fractures diagnosed by preoperative X-ray film and CT three-dimensional reconstruction were calculated and statistically analyzed. The fracture reduction, the position of internal fixation [measurement of tip-apex distance (TAD)]. and the reliability of internal fixation were observed after operation.
RESULTS: X-ray film was not easy to identify coronary fracture, and the coronal fracture line and the shape of the fracture piece weree clearly visible in CT three-dimensional reconstruction images. The morphological characteristics of the coronary fracture block: in AO/OTA 31-A1 type, the fracture line extended obliquely backward from the anterior tip of the large rotor, above the small rotor with or without small rotor fracture; in AO/OTA 31-A2 type, fracture line extended obliquely backward from the anterior tip of the large rotor to below the small rotor. Thirteen cases (28.3%) of coronal fractures were found on preoperative X-ray films, and 35 cases (76.1%) were found by CT three-dimensional reconstruction, showing significant difference ( χ 2=21.083, P=0.000). In AO/OTA 31-A1 type patients, the proportion of coronal fractures found by X-ray film and CT three-dimensional reconstruction was 18.2% (2/11) and 54.5% (6/11), respectively, and that in AO/OTA 31-A2 type patients was 31.4% (11/35) and 82.9% (29/35), respectively, showing significant differences ( χ 2=3.143, P=0.000; χ 2=20.902, P=0.000). Among the 35 patients with coronal fractures, 6 cases (17.1%) of AO/OTA 31-A1 type, 29 cases (82.9%) of AO/OTA 31-A2 type. The operation time of the patient was 80-112 minutes, with an average of 95 minutes; the intraoperative blood loss was 180-450 mL, with an average of 360 mL. There was no complication such as infection, falling pneumonia, and deep vein thrombosis of the lower extremities. At 3 days after operation, the internal fixators were all in the proper position. The TAD was 0.9-1.8 cm, with an average of 1.4 cm. All patients were followed up 14-18 months, with an average of 16 months. All the fractures healed osseously, and there was no complication such as nonunion and loosening of internal fixation.
CONCLUSION: CT three-dimensional reconstruction can better identify coronal femoral intertrochanteric fractures than X-ray films, and accurately recognize and analyze the incidence and morphological characteristics of coronal fractures, which can help formulate more effective surgical strategies to promote patient recovery.