Ulnar variance, or the difference in height between the joint surfaces of the distal radius and ulna, may play a role in several diseases of the wrist.

This study was to conduct a detailed analysis of ulnar variance in a wider case series by dividing the patients’ radiographs into groups according to age, gender, and side.

Twenty groups were created in order to investigate the change of ulnar variance according to age, gender, and side. Each group was planned to have 30 wrists. Wrist radiographs were scanned retrospectively, and ulnar variance was measured using the method of perpendiculars. Patients with any arthritic conditions, avascular necrosis, congenital deformities, bone and soft tissue tumors, and previous fractures or surgeries, and those radiographs which were not at the exact anteroposterior position, and with insufficient technique were not included the study.

Six hundred wrists 300 males (150 right, and 150 left wrists), and 300 females (150 right and 150 left wrists) were included in this study. There was a significant difference between the males (median: 0.4, minimum: −3.8, maximum: 5.1) and females (median: 0.85, minimum: −4.8, maximum: 5.7), regardless of the age and side (p=0.043). In the right wrists only (regardless of age), there was also a significant difference between the males (median: 0, minimum: −3.8, maximum: 5.1) and females (median: 0.8, minimum: −3.9, maximum: 5.7) (p=0.025). No statistically significant differences were found within the males and females with regard to aging, or between the sides in the same sex in any decade. In addition, there were no significant differences between the same sides in the males and females in any decade.

Although this study has one of the larger series in the literature, further studies should be done in different populations and ethnicities to obtain more accurate results, and to understand the relationship between ulnar variance and specific wrist disorders.

Level III.