Objective: To investigate the specific variables and influence factors of Harris scores in follow-up data of patients with internal fixation of femoral neck fracture.
Methods: From May 1999 to May 2004, 99 cases of femoral neck fracture receiving close reduction with cannulated screw and having complete follow-up data were evaluated in terms of age, sex, type of bone fracture (Garden classification), reduction time, reduction quality (Garden indicators), time of full weight-loading, removal of internal fixation, traction before operation, side of bone fracture, necrosis of femoral head, duration of follow-up and Harris score during follow-up period. Univariate and multivariate were analyzed by SPSS14.0 and SAS8.2.
Results: P-P probability plot and normal test revealed the Harris scores were non-normal distribution (W=0.75709, P=0.0001). By nonparametric test in univariate analysis, the following variables in Harris scores were of statistic significance: the time of reduction (U=-2.289, P=0.022), the Garden classification (H=16.943, P=0.001), the time of full weight-bearing (U=3.069, P=0.002), the quality of reduction (U=-3.448, P=0.001) and the necrosis of femoral head (U=-4.723, P=0.000). By the analysis of correlation, the following variables in Harris scores were of statistic significance: Garden classification (r(s)=-0.412, P=0.000), the time of reduction (r(s)=-0.231, P=0.021), the quality of reduction (r(s)=-0.348, P=0.000), the time of full weight-bearing (r(s)=-0.310, P=0.002), and the necrosis of femoral head (r(s)=-0.477, P=0.000). By the univariate logistic regression analysis, the following variables in Harris scores were of statistic significance: Garden classification (P=0.0001), the time of reduction (P=0.0126), the quality of reduction (P=0.0003), the time of full weight-bearing (P=0.0032), the traction before operation (P=0.0492) and the necrosis of femoral head (P=0.0001). By the multivariate logistic regression analysis, the influence factors of Harris scores rank included the necrosis of femoral head (P=0.0001), the time of reduction (P=0.0282), and Garden classification (P=0.0007).
Conclusion: Harris scores is of non-normal distribution, and the necrosis of femoral head is the most important factor influencing the function after applying internal fixation with cannulated screws to femoral neck fracture.