Internal rotation deformity and tardy ulnar nerve palsy after supracondylar humeral fracture

Infernal rofation deformity may contribute to the onset of tardy ulnar nerve palsy after a supracondylar fracture. We measured the angle of deformity in five patients with nerve palsy using an electrogoniometer and compared it with that of patients without palsy. Varus deformity of patients with nerve palsy was 23° ± 15.2° (mean ± SD), and that of patients without palsy was 12° ± 10.9°. No significant difference was seen between the two groups. Internal rofation deformity of patients with nerve palsy was 16° ± 4.2°, and that of patients without palsy was 2.5° ± 6.3° (p < 0.05). The results suggest that internal rotation deformity contributes to the development of tardy ulnar nerve palsy.