Factors related to dorsal angulation of distal radius in extra articular fractures of distal radius

Abstract

Introduction: The objective of this study was to predict the amount of redisplacement of dorsal tilt angle of Colles’ fracture with the size of dorsal cortical bone defect, radioulnar index difference, and age and patients’ gender. Method: Sixty two patients, 14 males and 48 females, with 63 cases of Colles’ fracture were treated by closed reduction and immobilized with short arm casts. They were evaluated radiographically for dorsal tilt angle before reduction, dorsal tilt angle after reduction, radioulnar index before reduction, radioulnar index after reduction, size of dorsal cortical bone defect after reduction and dorsal tilt angle at the end of immobilization at 4 to 6 weeks. Using the method of multiple regression analysis, we tried to construct the equation to predict the redisplacement of dorsal tilt angle of Colles’ fracture at the end of immobilization from the independent variables of size of dorsal cortical bone defect, radioulnar index difference, age and patients’ gender. Result: The mean of dorsal tilt angle was -0.70 degrees after reduction. The mean of dorsal tilt angle was 8.71 degrees at the end of the immobilization. The presence of size of dorsal cortical bone defect, and patients’ age and gender was found to have correlations with redisplacement of dorsal tilt angle of Colles’ fracture at the end of immobilization. For the estimation of dorsal tilt angle, the coefficient of partial correlation for dorsal cortical bone defect size was 0.177. For patient’s age, the coefficient was 0.202, and for gender, -8.207 (where 0=male and 1= female). The radioulnar index difference was not found to be correlated with redisplacement by dorsal tilt angle. The predicting equation for redisplacement of dorsal tilt angle of Colles’ fracture at the end of immobilization was Y =1.511+ 0.177 x1 + 0.202 x2 – 8.207 x3 where y = redisplacement of dorsal tilt angle of Colles’ fracture at the end of immobilization x1 = size of dorsal cortical bone defect x2 = patients’ age x3 = patients’ gender Conclusion: We concluded that the redisplacement of dorsal tilt angle of Colles’ fracture could be predicted from the initial data of dorsal cortical bone defect size, age and patients’ gender. The radioulnar index difference did not correlate with redisplacement of dorsal tilt angle of Colles fracture.