• Parts of a long bones:
1.
diaphysis (shaft),
2.
physis (growth plate),
3.
epiphysis (ends of bone, partially covered by articular cartilage),
4.
metaphysis (junction of diaphysis and epiphysis, most common site of primary bone tumors)
• Cross section:
1.
periosteum,
2.
cortex (composed of cortical bone or compact bone),
3.
medullary space (composed of cancellous or spongy bone)

OSTEOMYELITIS:
Denotes inflammation of bones and marrow.
• May be a complication of any systemic infection but frequently manifests as a
primary solitary focus of disease.

• PYOGENIC OSTEOMYELITIS: is almost always caused by bacteria.
1.
Hematogenous spread.
2.
Extension from a contiguous site.
3.
Direct implantation.
4.
E.coli and Pseudomonas.
5.
Mixed bacterial infections.
6.
Salmonella infections.

• Clinical Course:
• Fever ,chills, malaise, marked to intense throbbing pain over the affected region.
Diagnosis;
• Sign/symptoms.
• X-ray
• Blood cultures
• biopsy

Complications:
• Pathologic fracture.
• Secondary amyloidosis
• Endocarditis
• Sepsis
• Squamous cell carcinoma.

Tuberculous osteomyelitis:
Routes of entry;
• Usually blood borne and originate from a focus of active visceral disease.
• Direct extension (e.g. from a pulmonary focus into a rib or from tracheobronchial nodes into adjacent vertebrae) or spread via draining lymphatics.

Classification of primary tumors involving bones:
• Bone Forming tumors.
• Cartilage forming tumors.
• Fibrous and fibro-osseous tumors.
• Miscellaneous tumors.

• Suppurative Arthritis
• Tuberculous Arthritis
• Osteoarthritis
• Gout Arthritis
• Rheumatoid Arthritis

• Suppurative arthritis:
• Due to seeding of joint during bacteremia, most commonly due to Staphylococcus negative rods; rarely syphilis
, Streptococcus , gram
• Also due to postsurgical infection
• Neonates: often due to osteomyelitis
• Young women: most commonly due to gonorrhea
(gram negative intracellular diplococci, which is associated with multiple joint involvement, including the knee)
• Sickle cell disease: Salmonella

• Tuberculous arthritis:
• Insidious onset of chronic progressive arthritis, usually monoarticular in knee and hip; usually after osteomyelitis
• Leads to fibrous ankylosis of joint with obliteration of joint space
• Can detect from culture and examination of synovial fluid.
• PCR is sensitive; apparent false positives in clinically negative patients may represent early disease.

Degenerative joint disease:
• Also called osteoarthritis.
• Nonneoplastic disorder of progressive erosion of articular cartilage associated with aging, trauma, occupational injury.
• Usually age 50+ years (present in 80% at age 65 years)
• Cartilage degradation may be mediated by IL-1.
• Sites: men-hips, women-knees and hands; also first metatarsophalangeal joint, lumbar spine; usually one joint or same joint bilaterally, at least initially

• Symptoms: pain worse with use of joint, crepitus, limited range of motion, nerve root compression; Heberden nodes in fingers of women only (osteophytes at DIP joints)
• Secondary degenerative joint disease: younger patients with predisposing condition
(trauma, congenital, diabetes, obesity, ochronosis, hemochromatosis), such as knees of basketball players

• Gross: early changes are even degeneration of hyaline cartilage of articular surface, with fragmentation
• later thinning of cartilage and articular surface is often soft and granular with altered shape, sloughing of cartilage .
cysts: (synovial fluid forced into fractures via ball valvelike mechanism),
osteophytes: (bony outgrowths at margins of articular surface)

• Loose bodies: may form if portion of articular cartilage breaks off; normally loose body is nourished by synovium and continues to grow.

• Gout and gouty arthritis
• Transient attacks of acute arthritis initiated by crystallization of urates and neutrophils, followed by chronic gouty arthritis with tophi in joints and urate nephropathy
• Causes 2-5% of chronic joint disease
• Sites: 50% have initial attack in first metatarsophalangeal joint; also ankles, heels, knees, wrists, fingers, elbows

• Primary gout (90%): idiopathic (85%) with overproduction of uric acid or known enzyme defects.
• Secondary gout (10%): increased nucleic acid turnover due to leukemia/lymphoma, chronic renal disease.

• Gout is due to hyperuricemia and deposition of monosodium urate crystals in joints and viscera and uric acid kidney stone formation.
• Need serum urate > 7 mg/dl for deposition
(saturation threshold for urate at 98.6 F)
• Risk factors for gout with hyperuricemia are age
> 30 years, familial history of gout, alcohol use, obesity, thiazide administration, lead etc.

• Chronic systemic inflammatory disorder affecting synovial lining of joints, bursae and tendon sheaths; also skin, blood vessels, heart, lungs, muscles
• Produces nonsuppurative proliferative synovitis, may progress to destruction of articular cartilage and joint ankylosis
• 75% are women, peaks at ages 10-29 years; also menopausal women
• Sites: small bones of hand affected first (MCP, PIP joints of hands and feet), then wrist, elbow, knee

• X-ray: joint effusions, erosions
• narrowing of joint space; destruction of tendons, ligaments and joint capsules produce radial deviation of wrist, ulnar deviation of digits, swan neck finger abnormalities

Diagnosis:
• morning stiffness, arthritis in 3+ joint areas
• arthritis in hand joints,
• symmetric arthritis,
• rheumatoid nodules, rheumatoid factor, typical radiographic changes

Is a term that denotes increased porosity of the skeleton resulting from reduction in the bone mass.
Primary:
1- post menopausal
2- Senile
Secondary:
1Endocrine Disorders

 AGING
1↓ replicative activity of the osteoprogenitorcells
2- ↓ synthetic activity of the osteoblasts.
3↓ activity of the matrix bound growth factors.
 Menopause:
1- ↓ serum estrogen
2- ↑ IL-1,IL-6 levels
3- ↑ osteoclast activity
 Genetic factors
 Nutritional effects

Prevention Strategies
• The best long-term approach to osteoporosis is prevention.
• children and young adults, particularly women, with a good diet (with enough calcium and vitamin D) and get plenty of exercise, will build up and maintain bone mass.
• This will provide a good reserve against bone loss later in life.
• Exercise places stress on bones that builds up bone mass