guidebook. - Fanconi Anemia Research Fund

110
Fanconi Anemia: Guidelines for Diagnosis and Management
commonly the distal portion, and severe wrist radial
deviation. Complete absence of the radius is a Type IV
deformity and is the most common variant.
In complete absence of the radius (Type IV), the
humerus may or may not be shorter than expected and
the elbow is often lacking motion, primarily in flexion.
The forearm is always shorter as the ulna is approximately
60% of the normal length at birth. This length
discrepancy persists throughout the growth period. The
ulna is thickened and often bowed toward the absent
radius. Forearm rotation is absent in partial or complete
aplasia of the radius, although some rotation is evident
through the carpus. The wrist is positioned in a variable
amount of radial deviation. The carpal bones are
delayed in ossification with the scaphoid and trapezium
often absent or hypoplastic. The index and long fingers
can be stiff and slender with limited-motion joints. The
ring and small digits are less affected and often have
better motion.
The neurovascular structures are also aberrant because
the radial artery and nerve often are absent. The ulnar
nerve and artery are normal. An enlarged median nerve
substitutes for the absent radial nerve and supplies a
large dorsal branch for sensation to the radial aspect of
the hand. This branch is positioned in the fold between
the wrist and forearm, and knowledge of this subcutaneous
location is critical during surgery along the radial
aspect of the wrist.
Goals, indications, and contraindications for
treatment
The basic goals of treatment are to:
1) correct the radial deviation of the wrist;
2) balance the wrist on the forearm;