Rare congenital anomaly in hand: pre- and postaxial ipsilateral polydactyly

Abstract

Polydactyly is a common congenital abnormality that affects the fingers of the hand. The duplication can be preaxial, postaxial, or central. The different embryological origins and complex formation of the fingers make the association of different patterns in an ipsilateral form quite uncommon. These duplications can be bony or soft tissue and are graded based on their complexity and they are usually diagnosed at birth and should be treated by the age of 5.

The case involves a 9-year-old male patient with congenital deformities in both hands. The patient has complex polydactyly in the left hand, involving both preaxial (with a triphalangeal ulnar thumb) and postaxial components (with only soft tissue duplication). The postaxial deformity in the right hand also involved only soft tissue duplication. Additionally, there is a positive family history of polydactyly. Surgical intervention was initially chosen for the left hand due to its greater complexity. A postaxial supernumerary finger was excised. In the preaxial component, disarticulation of the more radial thumb, tendon and ligament transposition to the remaining finger, as well as osteotomy and distal interphalangeal arthrodesis were performed to correct clinodactyly and triphalangism. The patient progressed well, without complications, achieving good function and aesthetics after initial rehabilitation. Preaxial polydactyly is typically sporadic and unilateral, often associated with other syndromes. The association of these two forms in the same limb is rare due to the different pathways that lead to these deformities. The surgical approach varies depending on the type of polydactyly and the degree of limb involvement. Various surgical techniques are described, ranging from excisions of postaxial cases to severe preaxial deformities requiring complex reconstructions. The reported case is an example of a rare and severe congenital deformity treated surgically. The patient has good functionality and favorable aesthetics.