Ulnar hemimelia with humero-radial synostosis and oligodactyly: A rare congenital skeletal malformation

Abstract

Ulnar hemimelia is a rare congenital anomaly of the upper extremity which denotes the partial or complete absence of the distal half of a limb. This clinical condition has been classified into 4 types, with the rare Type 4 variant involving humeroradial synostosis. Notably, it is also strongly linked with extension or acute flexion of the elbow joint, variable length, and contour of the remnant of the ulnar in cases of incomplete hemimelia, oligodactly, and atrophy of the shoulder muscle. It may present clinically as functional deformity or cosmetic deformity. Thus, present a unique case of complete ulna hemimelia, humeroradial synostosis, and oligodactyly, in a 2-month-old male with upper limb shortening and restricted elbow movement since birth. He presented to the children's outpatient department of the hospital with a complaint of a small right upper limb, reduced muscle bulk, and limb activities of the same limb. The right upper limb was noted at birth to be shorter and less active than the left. Upon further evaluation, plain radiographs of the limbs revealed the right upper limb micromelia, with a single forearm bone. The right forearm bone has an expanded distal end (consistent with radial end), bowed with radial convexity, with the proximal end fused to the metaphysis of the adjoining right humerus. A diagnosis of right ulnar hemimelia with humero-radial synostosis, and oligodactly was made based on these findings. The patient has been on six monthly follow-ups for 2 years and no new complaints or complications have been recorded. The rarity of this clinical condition in our prevailing environment warranted this case report.