Radial clubhand is a term for a longitudinal deficiency of the radius and other structures on the radial side of forearm and hand. For example, absent thumb is a common accompaniment. Proximal deficiencies also can occur throughout the arm and shoulder girdle
Radial club hand is found in 1 per 100000 people. Radial club hand is bilateral in 50-70% patients.
It is associated with many syndromes as well
Radial clubhand was described first by Petit in 1733.
Radial club hand is bilateral in 50% of cases and is slightly more common in males than in females.
Associated Conditions
TAR
Autosomal recessive condition with thrombocytopenia and absent radius. Thumb is typically present
Fanconi’s Anemia
It is an autosomal recessive condition with aplastic anemia [Read more]
Holt-Oram syndrome
Autosomal dominant condition characterized by cardiac defects
VACTERL Syndrome
Vertebral anomalies, anal atresia, cardiac abnormalities, tracheoesophageal fistula, renal agenesis, and limb defects)
VATER Syndrome
Vertebral anomalies, anal atresia, tracheoesophageal fistula, esophageal atresia, renal agenesis)
CHARGE ( coloboma of the eye, heart defects, atresia of the nasal choanae, retardation of growth or development, genital or urinary abnormalities, and ear abnormalities and deafness) syndrome
Cause and Pathophysiology
Cause of radial club hand is not known but current theory relates defect in the ectodermal ridge, a thickened layer of ectoderm that directs differentiation of the underlying mesenchymal tissue and limb formation.
Spectrum of Findings in Radial Club Hand
The forearm is shortened, and the wrist is deviated radially leading to a perpendicular relationship between wrist and forearm.
This angulation between the wrist and forearm places flexor and extensor muscles at a disadvantage.
The ulna is two third of the normal length at birth and this discrepancy persists throughout life. True forearm rotation is absent.
The joint between the carpus and ulna is usually fibrous. Wrist motion is primarily in the radial/ulnar plane, with some flexion/extension.
Carpal bones ossification is delayed. The scaphoid and trapezium often absent or hypoplastic. The capitate, hamate, and triquetrum are usually present but ossify late.
Finger stiffness is seen. There is limited motion at the metacarpophalangeal and interphalangeal joints. The preaxial index and long fingers are more affected than the postaxial ring and small digits.
Scapula and humerus are smaller and deficiencies of the capitellum and trochlea are common.
Deltoid or pectoralis major muscle can be hypoplastic, partially absent, or have an abnormal insertion. The biceps may be absent or fused to the underlying brachialis muscle.
The forearm shows abnormalities of extensor carpi radialis longus, extensor carpi radialis brevis, pronator teres, flexor carpi radialis, palmaris longus, flexor pollicis longus, pronator quadratus, and supinator muscles. The extrinsic flexors and extensors of the fingers are usually adherent, with abnormal origins and insertions.
The flexor and extensor carpi ulnaris, as well as the interossei, lumbricals, and hypothenar muscles are often normal.
Abnormalities of the thumb muscles are related to the degree of thumb hypoplasia.
The radial nerve usually terminates at the elbow, and the ulnar nerve is normal. The median nerve is enlarged and compensates for the absence of the radial nerve by supplying a dorsal branch for dorsoradial sensibility. The radial artery is often absent, and the interosseous arteries usually remain patent.
Associated abnormalities as noted in syndromic associations could be seen
Classification of Radial Clubhand
Radial clubhand is classified into the following four types according to the amount of radius present:
Type I
- Mild radial shortening without considerable bowing
- Minor radial deviation of the hand is apparent
- Considerable thumb hypoplasia
- It is the mildest type of deficiency
Type II
- Small radius with distal and proximal physeal abnormalities
- Moderate deviation of the wrist
Type III
- Partial absence of the radius most commonly the distal portion
- Severe wrist radial deviation
Type IV
- The most common type
- Complete absence of the radius
- Hand perpendicular to the forearm
Clinical Presentation of Radial Clubhand
It varies with the degree of radial deficiency and the presence of associated anomalies. Radial deficiency is the classic anomaly that is associated with systemic conditions. All forms, regardless of the degree of expression, warrant systemic evaluation.
The shoulder, elbow, wrist, and digital range of movement are evaluated for active and passive motion. This establishes a baseline for assessing treatment outcome. The thumb is examined for hypoplasia and graded accordingly and stiffness of the fingers is assessed.
Imaging Studies
Plain x-rays are done to assess the degree of radial efficiency and to assess associated abnormalities of the elbow, wrist, and hand.
In radial clubhand, ossification is delayed, and final determination of complete aplasia of the radius or carpus must be deferred up to the age of 8 years.
The patient should be evaluated for possible associated diseases.
Lab Studies
Radial clubhand usually does not require lab studies for diagnosis.
But lab studies and imaging is required to rule out associated conditions wherever required.
Echocardiograph for the heart, ultrasound for kidney and blood count for platelets, and the platelet status is assessed by means of blood count and peripheral blood smear.
The most devastating associated condition is Fanconi anemia. Early detection via a chromosomal challenge test is critical and may ultimately save the affected child.
Treatment of Radial Clubhand
The basic goal of treatment is to maximize function and enhance the appearance of the upper limb by correcting wrist deviation, balancing the wrist on the forearm and promote the growth of the forearm
Passive stretching of the taut radial structures is started at the initial visit and performed at each diaper change and at bedtime. The splint is used when the forearm is long enough to accommodate a splint.
Mild deformity does not need any surgical treatment.
Other types need a surgical treatment called Centralization. Thumb hypoplasia also requires reconstruction. This procedure is performed on the patients aged approximately 1 year. Thumb reconstruction is usually delayed until after forearm treatment and usually done by 18 months of age.
Centralization procedure involves resection of varying amount of carpus, shortening of extensor carpi ulnaris, and, if needed, an angular osteotomy of the ulna is done.
Tendon transfers are used to attempt to correct the muscular imbalance and include advancing the extensor carpi ulnaris.
Contraindications for surgical intervention are a limited life expectancy in a child, mild deformity with adequate support for the hand (type 1), an elbow extension contracture that prevents the hand from reaching the mouth, and, in adults, adjustment to the deformity.
Recurrence is the most common source of failure after centralization
Patients with radial clubhand are required to be followed up into adulthood.
Leave a Reply