Bone Disorders Lecture PDF

 Contents: Bone disorders  Target students 302-MSK 102-2 BY: PROF. MAHMOUD TAG  Define osteomyelitis  Pathogenesis of osteomyelitis  Complication of osteomyelitis  Chronic and sub-acute osteomyelitis  Tuberculous osteomyelitis  Syphilitic osteomyelitis  Inflam...

 Contents: Bone disorders  Target students 302-MSK 102-2 BY: PROF. MAHMOUD TAG  Define osteomyelitis  Pathogenesis of osteomyelitis  Complication of osteomyelitis  Chronic and sub-acute osteomyelitis  Tuberculous osteomyelitis  Syphilitic osteomyelitis  Inflammation: Reaction of the living tissue against harmful stimuli.  Osteomyelitis: inflammation of bone with its soft tissue: bone marrow, Haversian canals and periosteum.  Bone marrow: Spongy tissue inside some bones. It contains stem cells that produce RBCs, WBCs and Platelets.  Haversian canal: Microscopic tubes in the bone that contains blood vessels and nerve fibers.  Periosteum: is a membrane that covers the outer surface of bones. Types of osteomyelitis: 1- Acute suppurative osteomyelitis 2- Sub-acute suppurative osteomyelitis 3- Chronic osteomyelitis: - Chronic suppurative osteomyelitis -Tuberculous osteomyelitis -Syphilitic osteomyelitis Causes: Staphylococcus aureus Predisposing factors: children, boys, trauma and hematoma Site: Metaphysis Routs of infection: Hematogenous and non hematogenous  Suppurative inflammation: inflammation which form pus (purulent exudate).  Abscess: Acute localized suppurative inflammation (Cavity contains pus)  Hematogenous spread: Spread by blood  Non Hematogenous spread: Direct spread after trauma or fracture Thrombosis of the vessels leads to cut of blood supply and necrosis of small parts of bone, known as Sequestrum. Sequestrum will be gradually separated from the surrounding living bone by osteoclastic activity. New born formation takes place by the stimulated osteoblasts and this is known as involucrum. It is crossed by many pores (cloacae) through which pus passes to the outside and the infection opens through the skin by multiple sinuses General: Toxemia, septicemia and pyemia Local: Chronic and amyloidosis Pathologic fracture Suppurative arthritis (rare) Sinus formation Sub–acute suppurative osteomyelitis Localized abscess Lined by granulation tissue Surrounded by sclerotic bone Define osteomyelitis What is Sequestrum, involucrum, sinus Define amyloidosis Explain the formation of granulation tissue  Chronic granulomatous disease  Granuloma: Aggregation of chronic inflammatory cells (histiocytes) arround a pathogen in a circular form  Cause: Mycobacterium tuberculosis  Central caseation necrosis It is usually a disease of children and the infection is hematogenous secondary to tuberculosis of the lungs or lymph nodes. Thoracic, abdominal and cervical vertebrae The infection usually starts in the center of the body of the vertebra which is more vascular with caseation necrosis and destruction of the bone and discs.  Deformity of the vertebral column  Pressure on the spinal cord  Cold abscess  Miliary tuberculosis  Amyloidosis  Cold abscess: It is a cavity contains caseous material. It is due to tuberculosis of bone. It is called cold abscess because it is not accompanied by classical signs of inflammation like redness, hotness and pain which are usually found in suppurative abscess.  Miliary tuberculosis: large number of mycobacterium tuberculosis travel through the blood and widely spread all over the body  Amyloidosis: It is deposition of abnormal, insoluble, misfolded protein in tissues.  Scoliosis: lateral curvature of the spine  Kyphosis: excessive backward curvature of the spine  Lordosis: excessive anterior curvature of the spine  Syphilis is a bacterial infection usually spread by sexual contact. The disease starts as a painless ulcer in genitals, rectum or mouth.  Syphilis spreads from person to person via skin or mucous membrane contact with these ulcers  Acquired syphilis: Primary stage: No bone affection Secondary stage: periostitis Tertiary stage: Gumma  Congenital syphilis: Saddle nose: collapse of nasal bridge Saber tibia: anterior bowing Gumma is a granulomatous reaction leads to destruction of the affected bone or thickening by sclerotic bone. These are a group of diseases, characterized by disturbances in the growth of bone. 1- Rickets 2- Osteomalacia. 3. Osteoporosis. 4. Osteitis fibrosa cystica. 5. Paget's disease.  The basic structure of bones is bone matrix. it is rigid framework of bones, composed of both compact bone and spongy bone. The bone matrix consists of tough protein fibers, mainly collagen, that become hard and rigid due to mineralization with calcium crystals.  There are three types of bone cells. Osteoblasts are bone-forming cell, Osteoclasts resorb or break down bone.  Osteocytes are mature bone cells.  Osteoprogenitor cells: Stem cells of bone Definition: It is a common bone disease of children Causes: It is due to deficiency of : Vitamin D, calcium, phosphate and UV rays of sun light - Excessive formation of osteoid tissue matrix with deficient calcification. - Failure of mineralization of the cartilage of the epiphyseal growth plate. - The bones are soft, liable to fracture and deformed. Rickety rosary: Harrison sulcus: a horizontal groove along Expansion of anterior the lower border of the rib ends at thorax corresponding to costochondral the costal insertion of the diaphragm junction Swelling of ends of long Rickety rosary bones due to cartilage proliferation  Deficiency of Vitamin D in adults  Deficient calcification of protein collagen matrix.  Adult females due to repeated pregnancies  Porous, soft and weak bones with deformity and fractures.  Osteoporosis: porous bone, is a disease in which the density and quality of bone are reduced. As bones become more porous and fragile, the risk of fracture is greatly increased.  Osteoporosis is due to inadequate osteoblastic activity -Senile osteoporosis -Diseases of bones and lack of physical activity: Poliomyelitis, paraplegia, fracture and lack of exercise. This may be due to absence of strains and pull of muscles and tendons which stimulate osteoblastic activity. -Hormones: Increase intake of cortisone or hypersecretion of adrenal cortical hormones as in Cushing's syndrome inhibit osteoblastic activity. 1. Pathological fracture particularly in the neck of femur. 2. Deformity of the vertebral column. 3. Diminished height of the patients: shortening due to collapse of the weak vertebra.  It is a skeletal disorder caused by increase secretion of parathyroid hormone (PTH) from overactive parathyroid gland(s). This hormone stimulates the activity of osteoclasts, cells that breakdown bone  Paget's disease of bone: osteitis deformans is a condition involving cellular remodeling and deformity of one or more bones. These structural changes cause the bone to weaken, which may result in deformity, pain, fracture or arthritis of associated joints. It is a triphasic disease begins with exaggerated osteoclastic activity (osteolytic phase), abnormal bone formation (mixed osteoclastic/osteoblastic phase) and finally gain in bone mass with disordered bone (osteosclerotic phase). Cause: It may be due to paramyxovirus infection. Early or acute phase: increase osteoclastic and osteoblastic activity with presence of immature irregular (woven bone) leads to mosaic pattern or jigsaw (puzzle) appearance. Late or chronic phase: thick trabeculae of abnormal bone with fine marrow fibrosis