Congenital hypoplasia of the first ray of the hand: causes, symptoms, diagnosis, treatment

Congenital hypoplasia of the first ray of the hand is a developmental disorder characterized by underdevelopment of the tendon-muscular, osteoarticular apparatus of the finger of varying severity with progression of the defect in the teratological row of the defect from the proximal end of the ray to the distal one.

ICD-10 code

• Q71.8 Congenital hypoplasia of the first ray of the hand.

Classification of congenital hypoplasia of the first ray of the hand

In the world the most common is the classification of congenital hypoplasia of the first ray of the Blauth brush. Depending on the severity of the defect, five degrees of this anomaly are distinguished.

• I degree - a slight decrease in the size of the first finger, hypoplasia of tons. Abductor pollicis brevis and opponens pollicis.
• II degree - the thumb is represented by all bone structures, however their sizes are reduced in comparison with the norm; note the narrowing of the first interdigital space, hypoplasia or aplasia of the surface muscles of thenar, instability of the metacarpophalangeal joint.
• III degree - the first interdigital space is narrowed, the anomaly of the development of the muscles of the thenar, as well as the long muscles of the thumb, the first metacarpal bone is hypoplastic up to the rudiment of the head in the distal part.
• IV degree - "dangling finger".
• V degree - aplasia of the 1st finger.

Indications for surgical treatment of congenital hypoplasia of the first ray of the hand are deformations of II-V severity. With grade II hypoplasia, the operation of removing and contrasting the first finger is performed in conjunction with stabilization of the metacarpophalangeal joint of the big toe (capsuloplasty, arthrodesis). Restriction of the bilateral grasp of the brush after the intervention requires the second stage of the opposing plastic. In those cases when the intraoperative manifestation of pronounced hypoplasia of the thenar muscles , and in some cases of the extensors of the first finger, the operation of tapping and contrasting the thumb is combined with the tendon plasty by Blauth-Thompson. There are two ways to restore the thumb of the hand with grade III-IV hypoplasia: the pollicization operation and the reconstruction of the first ray. When aplasia of the first ray of the hand, the pollicization operation is performed.

[1], [2], [3], [4], [5], [6], [7]