Hypoplastic Thumb



- See:
      - Absent Thumb
      - Pouce Flottant Thumb

- Discussion:
    - hypoplastic thumb is usually short, spindly, and malpositioned;
    - sometimes it is placed distally and radially on hand, & usually web space is narrow or extends distally;
    - most often there is deficiency of the intrinsic and extrinsic muscles;
    - osseous structures are also hypoplastic;
    - there may be fairly normal metacarpal with absent muscles, or the hand may have a very shortened metacarpal with almost no muscles;
    - individual phalanges of the thumb may be absent, small, or misshapen;

- Associated Anomalies:
    - hypoplastic first metacarpal may be an isolated or familial anomaly;
    - renal, skeletal, central nervous system, cardiovascular, GI, ear, palate, lip, face, genital, pulmonary, ophthalmologic, thalidomide 
            ingestion, mandibular facial dysostosis, trisomy 18, & thrombocytopenia;
    - hypoplastic slender first metacarpal can be present in the Holt-Oram syndrome, Fanconi's anemia, Cornelia de Lange's syndrome,
            diastrophic dwarfism, hand-footuterus syndrome, and myositis ossificans progressiva;
    - Holt-Oram syndrome is inherited as an autosomal dominant trait;
            - atrial septal defects and thumb abnormalities are commonly reported in association;
    - several syndromes are associated with the hypoplastic thumb, including radial club hand;
    - pollex abductus:
            - references:
                  - Pollex abductus in hypoplasia and duplication of the thumb.

- Treatment:
    - treatment is based on the severity of the deformity;
    - short thumb w/ hypoplastic thenar muscles: consider augmentation of intrinsics;
    - w/ hypoplasty thenar muscles and adducted thumb MCP consider soft tissue Z plasty;
    - deficient metacarpal: augment/bone graft or consider pollicization;
    - pouce flottant thumb
    - absent thumb



Symposium--The Thumb: Reconstruction of the Hypoplastic Thumb.

Pollicization of the index finger. Method and results in aplasia and hypoplasia of the thumb.

Type III-A hypoplastic thumb.

Long-term functional results after pollicization for the congenitally deficient thumb.

Index finger pollicization for congenital aplasia or hypoplasia of the thumb.

Reconstruction of the congenitally deficient thumb.

Pollicization of the index finger for reconstruction of the congenitally hypoplastic or absent thumb.

Reconstruction of a congenital hypoplastic thumb with use of a free vascularized metatarsophalangeal joint.

Primary shortening of the pollicized long flexor tendon in congenital pollicization 



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, May 22, 2012 9:28 am