Ulnar Ray Deficiency: A New Classification and a Unique Case Report.

Ulnar ray deficiency is a rare congenital upper limb defect. We report on a unique case with hand-on-flank deformity on the one side and limb truncation on the contralateral side. The standard of care for the hand-on-flank deformity is to do humerus osteotomy to reposition the hand anteriorly. However, the right limb truncation in our patient made the senior author decide not to do the osteotomy. Final assessment showed that the posterior hand position enabled the patient to reach the ano-genital areas, the pocket, and the mouth. It was concluded that in case of hand-on-flank deformity in one limb and limb truncation of the contralateral limb, osteotomies to bring the hand anteriorly are not advised.