[The ulnar longitudinal deficiency: proposition of a descriptive classification].

Ulnar longitudinal deficiency is an extended malformation sometimes involving the whole upper extremity, even including sometimes the opposite side. The clinical and radiological aspects are variable and none of the existing classifications takes into account all the possible deformities. Multiple decisive factors in the surgical indications are missing such as shoulder stability, elbow position (extension or flexion with or without pterygium), orientation of the hand (internal rotation), wrist inclination and number of digits. Based on a review of our 46 clinical cases as well as the published cases in the literature we have developed a simple way to describe each level.