Importance of measurement methods and demographic characteristics in evaluating ulnar variance: A retrospective comparative study.

Objective: This study aimed to compare 2 methods of ulnar variance (UV) measurement (the perpendicular method and the circular method) and to determine whether UV changed based on the demographic characteristics (sex and age).
Methods: UV was measured on bilateral wrist radiographs of 124 patients (62 men, 62 women; mean age=48.5 years; range=18-79 years) who had no history of trauma, congenital wrist anomaly, previous wrist surgery, and wrist osteoarthritis by a single radiologist with 4 years of experience. All measurements were made on standardized radiographic images using 2 methods: the perpendicular method and the circular method. All the patients were then divided into groups based on sex and age, and the study population was determined by selecting a similar number of patients for each sex and age group.
Results: The mean UV of the right and left wrists was measured as 0.33 (range=-4.3 to 5.7) mm by the perpendicular method and as 0.034 (range=-5 to 5.7) mm by the circular method. A significant difference was determined between the 2 measurement methods (p<0.001). There was a statistically significant difference between sex and UV values in the left wrist measurements by both methods (p<0.05). A significant correlation was found between the UV and age in both right and left side measurements, indicating a statistically significant difference between the methods (p<0.001).
Conclusion: The results of our study demonstrated significant differences in the UV measurement between the 2 methods. Furthermore, UV measurement may change based on age and sex. These differences should be considered in the treatment planning of patients with wrist disorders.
Level of Evidence: Level IV, Therapeutic Study.