الفهرس 
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Abstract
ajority of congenital hand anomalies occur during the fourth to eighth week of gestation where the rapid and fragile limb development takes place. Whereas after 8 weeks‘ gestation, the fetal period commences with differentiation, maturation, and enlargement of existing structures.
The hand consists of the bones and joints distal to the wrist (radiocarpal) joint. The human hand has 27 bones, not including the sesamoid bones which number varies between people. 14 of which are the phalanges of the fingers, five are the metacarpals and eight are the carpal bones. There are numerous synovial joints in the hand with their associated ligaments, with some syndesmotic ligaments. The muscles of the hand are subdivided into two groups: the extrinsic and intrinsic muscles. The extrinsic muscles are the long flexors and extensors. The intrinsic muscles are on the palmar aspect and it is divided into three groups: the thenar muscles with the adductor pollicis muscle, the hypothenar muscles and four lumbricals and seven interossei. The hand is innervated by the radial, median, and ulnar nerves. There are two arteries entering the hand (radial and ulnar), the branches of these arteries form two arterial arches (superificial and deep). The veins of the hand are divided into superficial and deep veins which anastomose frequently with each other.
The prevalence of congenital hand anomalies varies from country to country and increase with increasing maternal age. Male children are more commonly affected than female with a reported ratio of 3:2 for all categories of congenital hand anomaly other than generalized skeletal abnormalities. Bilateral congenital anomalies of the hand occur in half of the cases. The two most common conditions are syndactyly and polydactyly.
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Congenital hand anomalies can be classified in seven categories which are:
1. failure of formation
2. failure of differentiation
3. duplication
4. overgrowth
5. undergrowth
6. constriction ring syndrome
7. generalized skeletal abnormalities
This classification based on two parameters: embryonic failure during development and clinical diagnosis.
Congenital hand anomalies may have genetic (inherited), environmental or unknown (spontaneously) etiology, and it can be a part of a syndrome. The pathophysiology of congenital hand anomalies varies according to the damage during embryogenesis.
The congenital anomaly of the hand is present since birth although diagnosis of some anomalies such as distal symphalangism is delayed. Also, the course is almost always stationary, but some anomalies are progressive in course such as macrodactyly. The clinical presentations of congenital hand anomalies are varied. Radiographs should be taken at both upper extremities, both lower extremities, and the spine. If there is a suspicion that the hand anomaly is part of a syndrome, genetic studies must be done. Angiography is performed in macrodactyly to examine the arteries. Prenatal diagnosis is increasing with the progress of technology. Congenital hand anomalies represent various pathological findings.
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10% only of the patients with congenital hand anomalies require treatment. Congenital hand anomalies could be corrected by physiotherapy, orthotics, prosthetics or surgical corrections. Most surgeons perform the early surgery when the patient is in the second year of life to decrease the technical difficulty and the anesthetic risk. Many children require revision surgery following primary correction due to bone and soft tissue growth.
The most common complications associated with hand surgery are infection, poor healing, loss of sensation or range of motion in the hand, formation of blood clots, allergic reactions to the anesthesia but mild to severe pain may follow the surgery. Complications are relatively infrequent with hand surgery and can be successfully treated. Presence of hand anomaly leads to psychosocial complications.
We can decrease the incidence of congenital hand anomalies by decreasing the maternal age, by taking a prenatal vitamin that includes folic acid and by avoiding the use of tobacco and alcohol and by avoiding exposure to teratogens during pregnancy also by taking adequate periconceptional maternal folic acid. Improved imaging techniques permit earlier and more precise diagnosis of congenital hand anomalies. Also, there is technical changes that involve the increasing antenatal preventive surgery.
Lastly, we can conclude the following:
It is impossible to give an exact number for the incidence of congenital hand anomalies. The seven categories classification of congenital hand anomalies which was accepted by ASSH and IFSSH is imperfect. The future undoubtably holds a classification system based on improved knowledge of the molecular genetics
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underlying the anomalies. Congenital hand surgery has advanced during the last years with understanding of the basic pathology of hand anomalies. Microsurgery for congenital hand deformities is a highly specialized surgery as the surgeon needs to have in- depth knowledge of orthopedics, neurology, plastic surgery and neurosurgery. Parental counseling before the hand surgery and family support are necessary to prevent the psychosocial problems either early or late. Some anomalies such as intercalated transverse phocomelia at the arm or forearm levels, trigger thumb or fingers and Madelung’s deformity and arthrogryposis multiplex congenita are related to the congenital hand anomalies.
Finally, we recommend the following:
Clinical recommendations:
1. Public education about preconceptional and prenatal risks for congenital hand anomalies. (Primary prevention).
2. Teratogen information services and prenatal screening for fetal anomalies. (Primary prevention).
3. Programs for the detection of congenital malformations at birth, followed by early treatment. (Secondary prevention).
Reseach recommendations:
1. More researches are needed in congenital hand anomalies.
2. Establishing a national register system for all Egyptian researches. Presence of such system will allow recording of all Egyptian studies and so obtaining of these studies will be easier.