Radial Club Hand
What is radial club hand?
This condition scientifically called "Radial Dysplasia" also means abnormal development of the radius. Along with bone, the soft tissue developments in the forearm are also affected to a variable extent. Due to lack of support the hand deviates to radial side. Muscles controlling the wrist and digits may be either malformed or may be absent. The thumb can be smaller in size or can be absent.
Radial club hand is a present at birth. The exact cause of radial club hand is not completely known but it is associated with consumption of medicines like thalidomide, phenobarbitone, amitriptyline excessive alcohol etc. and most of them have been already banned and are not available in market.
Radial club hand develops very early in pregnancy when the bones of the hand are being formed. It may not always be possible to see these deformities on ultrasound during pregnancy. The deformity is usually present in both hands and two hands can be of different severity.
Does radial club hand interfere with hand function?
As described above in this condition the structures on the radial side of the hand are absent or may have poorly developed. As forearm has two bones the normal bone grows while the abnormal one doesn’t. This causes deviation of the hand towards the radial side. Along with deviation the flesh and its attachments and even the digits have abnormalities all of them contribute to limitation of hand function. Depending upon the severity of disease the arm and forearm also may be short and in severe degrees of deformity the elbow joint function is also abnormal.
Are there other serious issues involved?
Other congenital anomalies or syndromes may have radial club hand as part of their spectrum of deformities. Most of these syndromes affect cardiac, gastrointestinal and renal systems. So every child with radial club hand should be shown the paediatrician and should be evaluated for other deformities.
Are there any tests for diagnosis?
Typical appearance of radial club hand will give fair idea about the deformity. X ray examination is usually performed to know the severity of the disease (size of the radius) the deformity is graded according to the size of the radius and involvement of elbow joint
Further investigations might be required to rule out associated abnormalities.
How is the chance of developing function in this hand?
This deformity is classified in to four classes according the development of the radius. The outcome will strongly depend on the severity of the disease.
- Type 1: Typically, mildest form of disease where only the distal part of the radius is absent, the deformity is minimal and elbow is normal. It rarely needs surgical correction.
- Type 2: In this the radius is even shorter making the other bone (Ulna) bends more. The thumb deformity in these cases is more severe.
- Type 3: This is commonest form in which almost 2/3rds of radius is absent leading to gross deviation and thickening of ulna. Thumb is hypoplastic and wrist and elbow have limitation of ROM.
- Type 4: This type of radial club hand is second most common form causing great restriction of wrist and elbow movements. The radius is completely absent and the thumb also may be very rudimentary or absent. Elbow joint is involved and has limited ROM.
Is there any treatment?
For milder deformities only passive stretching and splinting the hand in proper position may be sufficient. This is also recommended in children with severe deformity a stretching will create space for deformity correction and one stage of surgery (distraction) can be avoided.
Understanding the limitation of surgical procedure is very important as no procedure will make the hand normal. The ideal age to perform surgery is from 6 months to 2 years. The aim of the surgery is to make the hand straight, increase reach of hand by positioning it distal to forearm bones (normal position), preserve as much as possible wrist movements, and maintain length of the affected limb and removing the scar tissue restricting growth.
All the surgical procedures are aimed at achieving these goals. That may involve distraction of the tissues to create space for the new bone. Release of all scar tissue restricting growth centralisation/ radialisation of the wrist and tendon transfers for rebalancing the muscles. Postoperative splinting in POP for 3 – 4 weeks is necessary.
Abnormal thumb and digits also may need treatment that has been discussed in other sessions of this write up.
What are complications of surgery?
Infection, bleeding may complicate any surgical procedure. Otherwise these are no major complications of this procedure. Sometimes in very deformed cases where after correcting the deformity a large space opens up on radial side that is filled with excess soft tissue from ulnar side. Necrosis of this flap can sometimes happen.
The severity of this deformity is good prognostic indicator. Though majority of children have severe deformity a timely performed operation with abovementioned goals can provide the child a helping hand.