A rare variant of mirror hand deformity

Abstract

Congenital hand and forearm anomalies pose a unique challenge in plastic and pediatric surgery. We present a case report of an 8-months-old girl with a congenital left sided hand and forearm anomaly, provisionally diagnosed as atypical left mirror hand anomaly. Classically there is absence of radius and duplication of ulna; however, our case had normal radius and ulna and a hand with seven digits arranged in two groups. We did a surgery which involved a ray amputation of the finger ulnar to the most radial digit, aiming to preserve an adequate first web space to reconstruct the thumb. The result of the surgical treatment in both functional and cosmetic aspects was, in authors’ opinion, good.

Successful surgical reconstruction of atypical variant mirror hand anomaly in a 2-year-old female child: a unique case report

“…Al-Qattan et al 2 classified this malformation as a spectrum of 5 types and many subtypes. The two main categories of mirror hand deformity based on the forearm bones: are the classic type, often referred to as ulnar dimelia, in which the forearm has two ulnae with the absence of a radius, and the non-classic type, in which the forearm has a radius and one or two ulnae 3 . Many Skeletal malformations may occur, such as the absence of the radial artery, the duplication of the ulnar artery, the shortness of the radial nerve, or the duplication of the ulnar nerve (occasionally with collaterals to the median nerve) 3 .…”

“…The two main categories of mirror hand deformity based on the forearm bones: are the classic type, often referred to as ulnar dimelia, in which the forearm has two ulnae with the absence of a radius, and the non-classic type, in which the forearm has a radius and one or two ulnae 3 . Many Skeletal malformations may occur, such as the absence of the radial artery, the duplication of the ulnar artery, the shortness of the radial nerve, or the duplication of the ulnar nerve (occasionally with collaterals to the median nerve) 3 . In this case, the patient has seven fully developed digits, no thumb, well-formed forearm formed from ulna and radius with proximal, we did not investigate the inner skeletal malformation as the forearm function was normal, and it did not need any therapeutic intervention.…”

“…Mirror hand’s aetiology is associated with the duplication of the ZPA signalling centre situated in the posterior margin of the limb bud. This duplicated signalling centre, driven by the sonic hedgehog protein, influences the development of the radio-ulnar axis 3 , 7 . It seems less likely that any synthetic medication taken during pregnancy is responsible for it 8 .…”

“…Various surgical procedures have been employed to repair the thumb, ranging from doing nothing to formal pollicization 10 , which may necessitate numerous complicated and repetitive surgeries. Because mirror hand defects are dynamic in nature, functional and anatomical alterations may occur even after a complete restoration 3 . In the surgical approach to the mirror hand, it is recommended to perform graded surgery and retain the limb in a long arm splint with the elbow flexed, wrist extended, and thumb abducted for 4-6 weeks.…”

“…Mirror hand deformity is classified into two main types according to the bones of the forearm: The classic type (also known as ulnar dimelia) in which the forearm contains two ulnae, and the non-classic type in which the forearm contains a radius and one or two ulnae. The main functional problems that need to be resolved are the stiff elbow and the polydactylous hand, which often requires surgery 3 . Here, we report an atypical presentation of Mirror hand and its successful surgical management, where follow-up revealed significant improvement of hand function and appearance.…”