Six-Part Classification of Femoral Intertrochanteric Fractures: A Classification Method to Improve the Diagnosis Rate of Unstable Fractures.

ABSTRACT

OBJECTIVE: Three-dimensional (3D)-CT data is currently insufficient for classifying femoral trochanter fractures. Fracture classification based on fracture stability analysis is helpful to evaluate the prognosis of patients after internal fixation. Currently, there is a lack of fracture classification methods based on 3D-CT images and fracture stability analysis. The aim of this study was to propose a new six-part classification method for intertrochanteric fractures of femur based on 3D-CT images and fracture stability analysis to improve the diagnosis rate of unstable fractures. METHOD: From January 2009 to December 2019, 320 patients receiving intramedullary nail surgery for femoral intertrochanteric fractures at Chengdu University's Affiliated Hospital were studied retrospectively. AO and six-part classifications were undertaken according to the 3D-CT image data of the patients, and the stability rates of two classifications were compared. According to the six-part classification stability criteria, the patients were divided into a stable and an unstable fracture group. The perioperative and follow-up indicators of the two groups were statistically analyzed, and the six-part classification's inter-observer and internal reliability was examined. RESULTS: There were 107 men and 213 females women the 320 patients, with an average age of 79.32 ± 11.26 years and an osteoporosis rate of 55.63% (178/320). The fracture stability rate of 39.69% (127/320) was studied using a six-part classification method. The AO classification fracture stability rate was 42.50% (136/320), with no significant difference (χ2 = 0.523, p = 0.470 > 0.05). There is no statistically significant difference between the two classification techniques in the examination of fracture stability (McNemer difference test p = 0.306 > 0.05; Kappa consistency test p < 0.001). According to the six-part classification, fracture stability and instability group were divided into two groups. The following indicators were compared between the two groups The surgery time (p = 0.280), fracture reduction quality (p = 0.062); function independent measurement (p = 0.075); timed up and go test (TUG) (p = 0.191), and Parker-Palmer score (p = 0.146). Were as compared according to the six-part classification of stable and unstable fracture groups. Perioperative blood loss (p < 0.001), the Harris score excellent and good rate (p = 0.043), fracture healing time (p < 0.001), and the entire weight-bearing duration (p = 0.002) were statistically significant. The difference in femoral head height (FHH) (p = 0.046), the change in femoral neck shaft angle (p = 0.003), the change in medial cephalic nail length (p = 0.033), and the change in tip-apex distance (TAD) (p = 0.002) were statistically significant compared to the relevant markers of imaging stability. Fracture stability had a substantial influence on Harris ratings at 3, 6, and 12 months following surgery, according to repeated measures analysis of variance (F(1,126) = 32.604, p < 0.001). The effect of time on the Harris score was similarly significant (F(1.893,238.508) = 202.771, p < 0.001). The observer intra-observer inter-group correlation coefficient (ICC) value was 0.941 > 0.75, the inter-observer ICC value was 0.921 > 0.75, and the intra-observer and inter-observer reliability were both good. CONCLUSION: The six-part classification of femoral intertrochanteric fractures based on 3D-CT images has broader guiding relevance for femoral intertrochanteric fracture stability analysis. Clinicians will find this classification simpler and more consistent than the AO classification.