الفهرس 
Sickle Cell AnemiaOnly 14 pages are availabe for public view
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Abstract
Some of the blood diseases affect the skeleton, thus mi ght constitute problems which should be
dealt with by the orthopedic surgeon. These diseases include hemoglobinopathies (thal assemia and
sickle cell anemia), hemophi l ia, leukemia, myel omatosis, histio cytosis-X, Gaucher disease and
Niemann-Pick disease.
Normal forms of hemoglobin inc lude: Hemogl obin A • adult Hb (a2 lh)
Hemogl obin A 2 • m i nor adult Hb (a2 6 2)
Hemoglobin F ’ fetal Hb (a2 Y’ ,)
Approximatel y 50 or more abnormal hemoglobin variants have been discovered, many of them are harml
ess. The abnormal hemogl obins which may produce
significant orthopedic problems are hemog lobin S, hemogl obin C, and the thalassemia type.
There are 2 mechanisms for initiating the bl ood c l otting, extrinsic and intrinsic pathways .
I. Tlt11l11sse•i11 :
It is an inherited disorder of hemogl obin synthesis characterized by absent or diminished
synthesis of one of the po lypeptide chains of human hemoglobin. It of two types: Alpha and Beta.
Also
when it is heterozygous cal led thalassemia minor, in between the two types there is thalassemia
intermedia.
• Skeletal changes in thalassemia:
1. Changes due to overgrowth of the bone marrow which affect the skull (thin tables and hair on end
appearance) , vertebrae (cup-shape), tubul ar bones (thin cortex and wide medul la), rib changes
(widening osteoporosis, localized lucencies, cortical erosion, rib within a rib deformity,
subcortical lucency and extramedul lary hematopoiesis) .
2. Premature fusion of the epiphysis occur in proximal end of the humerus, distal end of the femur
and proximal tibia. It may be eccentric or central fusion. The deformity occur by tilt of the
epiphysis towards the site of fusion .
3. Arthritis in thalassemia in the form of recurrent painful joint swel ling.
4. Growth and sexual maturation are suppressed.
Laboratory findings in the form of hypochromic microcytic anemia, basophil ic stippling, increase
the resistance of red cel ls to hemolysis in hypotonic salt solution, polychromasia, and presence
of oval and target cells.
Orthopedic compl ications spinal cord compression and specially in the long bones.
of thalassemia include pathological fractures
II. Sickle cell dise4se:
It is a hemogl obinopathy in which the red cel l contains abnormal hemoglobin (Hb S).
Genetic variants include sickle cel l trait, sickle cel l anemia, sickle cel l hemoglobin C disease
and sick le cel l B thalassemia.
As regards bone lesions in sickle cel l anemia:
1. Lesions due to hyperpl asia of the bone marrow which l ead to thin cortex , widening of the
medul la, loss of trabec ul ar pattern and trabecul ar definition. These lesions appear in the skul
l (hair on end appearance) , vertebrae (cupping), tubular bones and flat bones .
2. Lesions due to infarction of the bone as a result of plugging (thrombosis )of the blood vessels
by masses of sickled cel ls are in the form of sickle cel l dactyl itis ”Hand-foot syndrome• and
long bone infarction.
Avascul ar necrosis of the femoral head also occurs
and takes the form of subchondral sc lerosis, Perthes- 1 ike lesions type 1, Perthes -l ike lesions
type 2, total destruction, central necrosis and diffuse necrosis.
3. Terminal phalangeal sclerosis in the hand.
4. Salmonel la osteomyel itis manifested by early periosteal reaction along the whole length of the
shaft of the bone •
5. Arthritis may occur and usual ly polyarticular, also growth disturbance and sexual depression
occur.
6. Leg ulcers tend to occur around the ankl e and anterior tibia •
7. In genetic variants, the lesions do not occur in trait but may occur in hemogl obin S-C disease
and sickle-beta thalassemia.
8. Laboratory examination shows marked anemia and sick led forms are usual ly seen •
9. Special tests inc lude hemogl obin electro phoresis and sickling test.
III. He•ophilia:
It is a hereditary coagulatory disorder, determined as a result of deficiency of coagulation
factors VIII, IX or XI and most often has a sex-linked recessive transmission from the affected
male through the unaffected female offspring to another male.
The pathologic changes in hemophi lia are attri buted to the occurrence of hemorrhage in the muscl
es, bones or joints. In the joints the pathol ogical changes are in the synovial membrane and in
the bones forming the joint. In the synovial membrane there is synovial hyperpl asia related to the
irritation of hemosiderin deposited in the subsynovial layer. The cartilage is destroyed by the
action of certain enzymes. There are pathological changes in the muscl es and bones outside the
joint due to bleeding intramuscularly or subperi osteal ly in the form of hemophi l ic bl ood
cysts or pseudotumors. The hemophil ic patient may present with acute or chronic problems. The
acute problems in the form of acute hemarthrosis, bleeding intramuscul arly or subperiosteal ly.
The chronic presentation in the form of chronic hemophi l ic arthropathy and the so-cal led
pseudotumor. The radiographic picture of hemophil ia is attributed to the occurrence of hemorrhage
in the joints, musc les and bones. Early in the joints, there is shadow of soft tissue swel l ing,
osteoporosis and later there is destruction of carti lage, erosion of bone, narrowing of the joint
space and the appearance of bone cysts. The. radiographic picture of the pseudotumor shows soft
tissue mass with periosteal elevation which may assume a semilunar character pro jecting away from
the bone into the soft tissues, the semilunar projection have been cal led a periosteal cuff and
there is erosion of bone of the adjacent ccrtsx.