SPECIFICS OF DIAPHYSEAL HUMERUS FRACTURES HEALING IN PATIENTS TREATED BY ILIZAROV EXTERNAL FIXATION

Based on the literature data analysis a hypothesis was made that specific features of humeral diaphyseal fractures consolidation process in result of Ilizarov method treatment depend on their quantitative characteristics.

Purpose of the study – to develop quantitative characteristics of diaphyseal humerus fractures and to analyze their correlation to the terms of bone fragments healing.

Materials and methods. The authors studied X-rays of forty one patient with diaphyseal humerus fractures; age of patients ranged from 21 to 60 years (median – 37 years), there were 19 male and 22 female patients. The authors worked out the formulas using Weasis software for quantitative characteristics of diaphyseal humerus fractures: distance of the fracture site from proximal metaphysis of the humerus, extension of the fracture line and degree of bone fragments displacement. During statistical analysis of the recorded data the average standard deviation, median, minimum, maximum, 25th percentile and 75th percentile were calculated. The Shapiro-Wilk test was used to check consistency of recorded data with normal distribution of characteristics. Correlation analysis was performed by calculation of Kendall and Pearson coefficients. Statistical processing of reported data was done by means of unpaired criteria: non-parametric Wilcoxon test and parametric Student t-test. When comparing two samples a null hypothesis was rejected at the level of test significance p≤0.05. The authors utilized Microsoft Office Excel 2007 and AtteStat, version 13.1.

Results. Statistical analysis of the samples including comminuted and spiral fractures of humeral diaphysis demonstrated that the level of the fracture was within 40.9±19.9% and distributed from 11.6% to 72.4% along the diaphysis. Correlation analysis demonstrated statistically valid moderate negative relation between the level of fracture site and consolidation period (Pearson correlation coefficient r = -0.46; р = 0.0091). There is a statistically valid positive moderate relation between extension of the fracture line and consolidation period (Pearson correlation coefficient r = 0.43; р = 0.015). Statistically valid positive and weak relation was observed between the value of “post-reduction displacement” of bone fragments and consolidation period (Kendall correlation coefficient τ = 0.25; p = 0.045). Within the group of comminuted and spiral diaphyseal fractures of the humerus the authors observed a statistically valid longer consolidation period in the sample with diaphyseal fractures, located up to 48.4% away from the proximal end of the humerus as compared to the sample of fractures, located below the indicated border.

 Conclusions. Consolidation period of the diaphyseal humerus fractures demonstrated statistically valid correlation with the following characteristics of the fracture: 1) fracture location: the closer to the distal end of the humerus the shorter is consolidation term; 2) extension of the fracture site: the longer is the fracture line the longer is consolidation period; 3) post-reduction degree of bone fragments displacement: the larger is the degree of displacement the longer is consolidation period. The correlations observed during the study are true for diaphyseal humerus fractures located within 11 to 72% away from the proximal end of the humerus.