True congenital gigantism: causes, symptoms, diagnosis, treatment

True congenital gigantism (macrodactyly) is a developmental defect caused by a violation of the linear and volumetric parameters of the upper limb towards an increase.

ICD-10 code

Q74.0 True congenital gigantism (macrodactyly).

Classification and symptoms of true congenital gigantism

There are three forms of this anomaly.

• The first form is true congenital gigantism with predominant soft tissue enlargement. Distinctive features: increase in length and volume of all limb segments, sharp increase in soft tissue mainly on the palmar surface of the hand (the limb has an ugly appearance); the degree of soft tissue enlargement in length and especially in width exceeds the degree of enlargement of the skeletal bones compared to the age norm. Clinodactyly is also observed at the level of the interphalangeal and metacarpophalangeal joints of the affected fingers, hyperextension in them.
• The second form is true congenital gigantism with a predominant increase in the bone component. Characteristic signs: increase in the length of the affected limb segments (soft tissues do not change the appearance of the affected segment); the degree of increase in the width and especially in length of the skeletal bones exceeds the degree of increase in soft tissues compared to the age norm; clinodactyly at the level of the interphalangeal and metacarpophalangeal joints of the affected fingers, hyperextension in them is absent.
• The third form is true congenital gigantism with predominant damage to the short muscles of the hand (muscular form). Characteristic signs: increase in the length of the affected segment of the limb due to the metacarpal bones; increase in the volume of soft tissues of the forearm; significant increase in the width of the palm due to the intercarpal spaces; compared to the age norm, the degree of increase in soft tissues (only at the level of the heads of the metacarpal bones) in width significantly exceeds the degree of increase in the bones of the skeleton (in length, only an increase in the bone component is noted). Clinodactyly and flexion contractures are detected in the metacarpophalangeal joints, and "looseness" is also observed in the joints of the first finger.

Treatment of true congenital gigantism

Surgical treatment of children with gigantism of the upper limb of varying degrees begins at the age of 6-7 months. It is possible to reduce the length of the enlarged finger to the norm by shortening resection of the phalanges and metacarpal bones. Elimination of clinodactyly of the affected fingers is carried out simultaneously with their shortening.

Elimination of syndactyly of the affected fingers is performed after their length has been completely normalized.

If the toe is enlarged by 300% of normal (or more) and the only solution is amputation, we offer microsurgical toe transplantation onto the hand (in the position of the excessively enlarged fingers).

• In the first form of gigantism, the volume of the affected segment can be reduced to almost normal dimensions using lateral resection of the phalanges, which is performed in two stages: first on one side of the finger, then on the other.
• In the second form of gigantism, central resection of the phalanges is performed to reduce the size of the finger.
• In the third form of gigantism, to reduce the width of the palm and simultaneously eliminate flexion contractures in the metacarpophalangeal joints, a method of bringing the metacarpal bones closer together with various methods of fixation is used (depending on the age of the child and the severity of the deformity).

Simultaneously with the elimination of the main manifestations of the defect, correction of the accompanying deformities is performed: excision of excess soft tissues of various localizations, elimination of hyperextension of the affected fingers, elimination of “looseness” in the metacarpophalangeal joint of the first finger.

The applied methods of orthopedic surgical treatment allow to bring the sizes of enlarged segments closer to the physiological norm while maintaining the anatomical proportions of the hand.