Rotational deformity of the distal humerus in cubitus varus.

The medial rotation deformity of the distal humerus usually exists in the cubitus varus deformity but has received little attention. Study of this deformity in 29 cases of cubitus varus was carried out using the osteotomized bony specimens that were removed during closed wedge osteotomy in order to determine the actual bone deformity. The average duration of the varus deformity was 5.6 yrs (range 1 to 11). The medial rotation deformity of the distal humerus averaged 27 degrees (range 15 to 45). There was no correlation between the degree of rotation and that of the varus deformity (correlation coefficient r = 0.15). The affected-side shoulder compensated well in both internal and external rotation, and had a greater arc of rotation than that of the normal side. The affected-side shoulder exhibited an internal rotation deformity with an average of 16 degrees (range 5 to 25), with restriction of external rotation of only 13 degrees (range 0 to 20) in comparison to normal side shoulder.