Blauth Classification
Grade I
Minor hypoplasia, all element presents
May need opposition tendon transfer if APB deficient
Grade II
Normal skeleton
Thenar muscles hypoplasia / aplasia
MCPJ ligament instability
Wed space adduction contracture
Management
- release web space
- stabilize MCPJ
- oppensplasty
Grade III
Skeletal hypoplasia / variable absence MC / aplasia of CMC
Management - pollicisation
Grade IV
Absent metacarpal / rudimentary phalanges / floating thumb
Management - tie off at birth / pollicisation
Grade V
Total absence
Management - pollicisation
Pollicisation
Concept
Use index finger as thumb
- aim for opposition
- pulp to pulp with middle finger