Disorders of Skeletal system Lecturer: Dr.Zainab Sajid Al-Shimmari

1. Disorders of Skeletal system Lecturer: Dr.Zainab Sajid Al-Shimmari

2. OSTEOPOROSIS. i)-Osteoporosis is a skeletal disorder characterized by the loss of bone mass and deterioration of the architecture of cancellous bone with a subsequent increase in bone fragility and susceptibility to fractures. ii)- Osteoporosis can occur as the result of an endocrine disorder or malignancy,it most often is associated with the aging process. iii)-After maximal bone mass is attained at 30 years of age, the rate of bone resorption exceeds formation, causing a continuous loss of bone mass.

3. Causes. 1-Poor nutrition or an age-related decrease in intestinal absorption of calcium because of deficient activation of vitamin D may contribute to the development of osteoporosis, particularly in the elderly. 2-Hormonal factors play a significant role in the development of osteoporosis, particularly in postmenopausal women. Postmenopausal osteoporosis, which is caused by an estrogen deficiency, is manifested by a loss of cancellous bone and a predisposition to fractures of the vertebrae and distal radius.

6. 3-Testosterone deficiency may contribute to bone loss in men with senile osteoporosis, although the effectis not of the same magnitude as that caused by estrogen deficiency. 4-Secondary osteoporosis is associated with many conditions,including endocrine disorders, malabsorption disorders,malignancies, alcoholism, and certain medications. 5-The prolonged use of medications that increase calcium excretion, such as, corticosteroids, and anticonvulsants,also is associated with bone loss.

7. 6-Persons with human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) who are being treated with antiretroviral therapy may develop a lower bone density and signs of osteoporosis and osteopenia. 7-Children are at increased risk for decreased bone mass, including premature and low-birth-weight infants who have lower than expected bone mass in the early weeks of life, children who require treatment with corticosteroid drugs .children with cystic fibrosis, and those with hypogonadal states . Children with cystic fibrosis often have impaired gastrointestinal function that reduces the absorption of calcium and other nutrients, and many also require the frequent use of corticosteroid drugs.

8. Manifestations. 1-Osteoporotic changes occur in the diaphysis and metaphysic of bone. The diameter of the bone enlarges with age, causing the outer supporting cortex to become thinner. 2-In severe osteoporosis, the bones begin to resemble the fragile structure of a fine porcelain vase. a-There is loss of trabeculae from cancellous bone and thinning of the cortex to such an extent that minimal stress causes fractures. b-The changes that occur with osteoporosis have been explained by two distinct disease processes affecting women early and late in life.

9. 3-Type I is caused by early postmenopausal estrogen deficiency and is manifested by loss of trabecular bone, with a predisposition to fractures of the vertebrae and distal radius. 4-Type II (i.e., senile osteoporosis) is caused by a calcium deficiency and is a slower process in which cortical and trabecular bone are lost. Hip fractures, which are seen later in life, result from the second type.

10. 5-Osteoporosis is usually a silent disorder. Often, the first manifestations of the disorder are those that accompany a skeletal fracture—a vertebral compression fracture or fractures of the hip, pelvis, humerus, or any other bone. 6-Systemic symptoms such as weakness and weight loss suggest that the osteoporosis.

11. Osteomalacia. Osteomalacia is a generalized bone condition in which inadequate mineralization of bone results from a calcium or phosphate deficiency, or both. It is sometimes referred to as the adult form of rickets. Causes. There are two main causes of osteomalacia: 1-insufficient calcium absorption from the intestine because of a lack of calcium. 2-resistance to the action of vitamin D and phosphate deficiency due to increased renal losses or decreased intestinal absorption.

13. 3-A form of osteomalacia called renal rickets occurs in persons with chronic renal failure. It is caused by the in ability of the kidney to activate vitamin D and excrete phosphate and is accompanied by hyperparathyroidism, increased bone turnover, and increased bone resorption.4-Another form of osteomalacia results from renal tubular defects that cause excessive phosphate losses. This form of osteomalacia is commonly referred to as vitamin D–resistant rickets and often is a familial disorder.

14. 5- Another cause of phosphate deficiency is the long-term use of antacids, such as aluminum hydroxide, that bind dietary forms of phosphate and prevent their absorption. 6-The incidence of osteomalacia is high among the elderly because of diets deficient in calcium and vitamin D and often is compounded by the intestinal malabsorption problems that accompany aging.

15. Manifestation. 1-The clinical manifestations of osteomalacia are bone pain, tenderness, and fractures as the disease progresses. In severe cases, muscle weakness often is an early sign. 2-The combined effects of gravity, muscle weakness, and bone softening contribute to the development of deformities. There may be a dorsal kyphosis in the spine, rib deformities, a heart shaped pelvis, and marked bowing of the tibiae and femurs.

16. 3-Osteomalacia predisposes a person to pathologic fractures in the weakened areas, especially in the distal radius and proximal femur. In contrast to osteoporosis, it is not a significant cause of hip fractures. There may be delayed healing and poor retention of internal fixation devices. 4-Osteomalacia usually is accompanied by a compensatory or secondary hyperparathyroidism stimulated by low serum calcium levels. Parathyroid hormone reduces renal absorption of phosphate and removes calcium from the bone. Serum calcium levels are only slightly reduced in osteomalacia.

17. Rickets Rickets is a disorder of vitamin D deficiency, in adequate calcium absorption, and impaired mineralization of bone in children. Children with rickets manifest inadequate mineralization not only of bone but also of the cartilaginous matrix of the epiphyseal growth plate. Causes. 1-The causes are inadequate exposure to sunlight and prolonged breast-feeding without vitamin D supplementation. the vitamin D content of human milk is low, the combination of breast milk and sunlight exposure usually provides sufficient vitamin D.

18. 2-Another cause of rickets is the use of commercial alternative milks (e.g., soy or rice beverages)that are not fortified with vitamin D.3-A dietary deficiency in calcium and phosphorous may also contribute to the development of rickets. 4-A newly discovered genetic mutation also can cause vitamin D deficiency rickets, a condition that does not respond to simple vitamin supplementation.The mutation results in the absence of a critical enzyme in vitamin D metabolism.

19. Manifestations. 1- Bones become deformed;ossification at epiphyseal plates is delayed and disordered,resulting in widening of the epiphyseal cartilage plate. Any new bone that does grow is un mineralized. 2-The symptoms of rickets usually are noticed between6 months and 3 years of age. The child usually has stunted growth, with a height sometimes far below the normal range. Weight often is not affected so that the children,many of whom present with a protruding abdomen.

20. 3-Early symptoms are lethargy and muscle weakness, which may be accompanied by convulsions or tetany related to hypocalcemia.Irritability is common.4- In severe cases, children lose their skin pigment, acquire flabby subcutaneous tissue, and have poorly developed musculature. The ends of long bones and ribs are enlarged. The thorax may be abnormally shaped, with prominent rib cartilage . 5-The legs exhibit bowleg or knock-knee deformities. The skull is enlarged and soft, and closure of the fontanels is delayed. Teeth are slow to develop, and the child may have difficulty standing.

21. RHEUMATOID ARTHRITIS Rheumatoid arthritis (RA) is a systemic inflammatory disease that affects 0.3% to 1.5% of the population, with women affected two to three times more frequently than men. Although the disease occurs in all age groups, its prevalence increases with age. The peak incidence among women is between the ages of 40 and 60 years, with the onset at 30 to 50 years of age.

22. Causes. 1-A genetic predisposition and the development of joint inflammation that is immunologically mediated. the disease is initiated by the activation of aT-cell–mediated response to an immunologic trigger, such as a microbial agent. 2-the neutrophils, macrophages, and lymphocytes are attracted to the area. The neutrophils and macrophages phagocytize the immune complexes and, in the process, release lysosomal enzymes capable of causing destructive changes in the joint cartilage.

23. I-Joint Manifestations. 1-The person may complain of joint pain and stiffness that lasts 30 minutes and frequently for several hours. The limitation of joint motion that occurs early in the disease usually is because of pain; later, it is because of fibrosis. 2- The fingers often take on a spindle-shaped appearance because of inflammation of the joints. 3-Progressive joint destruction may lead to sub luxation(i.e., dislocation of the joint resulting in misalignment of the bone ends) and instability of the joint and in limitation of movement.

24. 4-Swelling and thickening of the synovium can result in stretching of the joint capsule and ligaments. When this occurs, muscle and tendon imbalances develop, 5-The knee is one of the most commonly affected joints and is responsible for much of the disability associated with the disease.6- Active synovitis may be apparent as visible welling that obliterates the normal contour over the medial and lateral aspects of the patella. The bulge sign,which involves milking fluid from the lateral to the medial side of the patella, may be used to determine the presence of excess fluid when it is not visible.

29. II-Extraarticular Manifestations. 1- RA is a systemic disease, it may be accompanied by complaints of fatigue, weakness, anorexia, weight loss, and low-grade fever when the disease is active.2- The erythrocyte sedimentation rate (ESR), which commonly is elevated during inflammatory processes, has been found to correlate with the amount of disease activity.3-Anemia associated with a low serum iron level or low iron-binding capacity is common. This anemia usually is resistant to iron therapy.

30. 4-Rheumatoid nodules are granulomatous lesions that develop around small blood vessels. 5-Vasculitis, or inflammation of small and medium sized arteries . 6- ischemic areas in the nail fold and digital pulp that appear as brown spots.7-Ulcerations may occur in the lower extremities. Neuropathy may be the only symptom of vasculitis. 8-The visceral organs, such as the heart, lungs, and gastrointestinal tract, also may be affected. eye lesions such as episcleritis and scleritis,

33. SYSTEMIC LUPUS ERYTHEMATOSUS Systemic lupus erythematosus (SLE) is a chronic inflammatory disease that can affect virtually any organ system, including the musculoskeletal system. It is a major rheumatic disease. Causes: 1-The cause of SLE is unknown. It is characterized by the formation of autoantibodies and immune complexes. Persons with SLE appear to have B-cell hyper reactivity and increased production of antibodies against self (i.e., autoantibodies) and non self antigens.

34. 2- These B cells are polyclonal, each producing a different type of antibody. The auto antibodies can directly damage tissues or combine with corresponding antigens to form tissue-damaging immune complexes. 3-Other antibodies may be produced against various cells, including red blood cell surface antigens,platelets, coagulation factors, and other antibodies.

35. 4-The development of autoantibodies in SLE can result from a combination of factors, including genetic, hormonal,immunologic, and environmental factors. 5-sex hormone levels may play a role in the development of the disease, especially because the disease is so prevalent among women. Androgens appear to protect against the development of SLE, whereas estrogens seem to favor its development. 6-Possible environmental triggers include ultraviolet (UV) light, chemicals (e.g., drugs, hair dyes), some foods,and infectious agents.

36. Clinical Manifestations 1-Arthralgias and arthritis are among the most commonly occurring early symptoms of SLE; approximately 90% of all persons with the disease complain of joint pain at some point during the course of their disease. 2-The polyarthritis of SLE initially can be confused with other forms of arthritis, especially rheumatoid arthritis, because of the symmetric arthropathy.Flexion contractures, hyperextension of the interphalangeal joint contribute to the deformity and subsequent loss of function in the hands.

37. 3-Other musculoskeletal manifestations of SLE include tenosynovitis, rupture of the intrapatellar and Achilles tendons, and a vascular necrosis, frequently of the femoral head. 4-Skin manifestations can vary greatly and may be classified as acute, subacute, or chronic. The acute skin lesions include the classic malar or “butterfly” rash on the nose and cheeks .

40. 5-Hair loss is common. Mucous membrane lesions , Sun sensitivity,Renal involvement, several forms of glomerulonephritis,Interstitial nephritis , Nephrotic syndrome causes proteinuria with resultant edema in the legs, abdomen,and around the eyes,Pulmonary involvement , pleuritis, acute pneumonitis, pulmonary hemorrhage,chronic interstitial lung disease, and pulmonary embolism.Pericarditis is the most common of the cardiac manifestations,Myocarditis affects as many as 25% of those with SLE.

43. Ankylosing Spondylitis 1-Ankylosing spondylitis is a chronic, systemic inflammatory disease of the joints of the axial skeleton manifested by pain and progressive stiffening of the spine. 2- Clinical manifestations usually begin in late adolescence or early adulthood and are slightly more common in men than in women.

44. 3-Ankylosing spondylitis produces an inflammatory erosion of the sites where tendons and ligaments attach to bone. spine. 4-The result is ultimate destruction of these joints with ankylosis or posterior fusion of the spine. The vertebrae take on a squared appearance and bone bridges fuse one vertebral body to the next across the intervertebral discs .

45. Clinical Manifestations.1-The person with ankylosing spondylitis typically complains of low back pain, which may be persistent or intermittent. 2-Lumbosacral pain also may be present, with discomfort in the buttocks and hip areas. Sometimes, pain can radiate to the thigh in a manner similar to that of sciatic pain. 3-Prolonged stiffness is present in the morning and after periods of rest. Muscle spasm also may contribute to discomfort.

46. 4-Loss of motion in the spinal column is characteristic of the disease. Loss of lumbar lordosis occurs as the disease progresses, and this is followed by kyphosis of the thoracic spine and extension of the neck. 5-A spine fused in the flexed position is the end result in severe ankylosing spondylitis. Peripheral arthritis is more common in hips and shoulders. 6-The acute anterior uveitis, which occurs in 25% to 30% of patients

48. Osteoarthritis Syndrome 1-Osteoarthritis (OA), formerly called degenerative joint disease, is the most prevalent form of arthritis and is a leading cause of disability and pain in the elderly. 2-It can occur as a primary idiopathic disorder or as a secondary disorder, Idiopathic or primary variants of OA occur as localized or generalized (i.e., involvement of more than three joints) syndromes. Secondary OA has a known underlying cause such as congenital or acquired defects of joint structures. 3-The joint changes associated with osteoarthritis, which include a progressive loss of articular cartilage and synovitis,