Bone PathologyBone Pathology

Normal anatomy of Normal anatomy of bones bones • Parts of a long bones:Parts of a long bones:

1.1.diaphysisdiaphysis (shaft), (shaft),

2.2.physisphysis (growth plate), (growth plate),

3.3.epiphysisepiphysis (ends of bone, partially covered by (ends of bone, partially covered by articular cartilage),articular cartilage),

4.4.metaphysismetaphysis (junction of diaphysis and epiphysis, (junction of diaphysis and epiphysis, most common site of primary bone tumors)most common site of primary bone tumors)

• Cross section:Cross section:

1.1.periosteum,periosteum,

2.2.cortex (composed of cortical bone or compact cortex (composed of cortical bone or compact bone), bone),

3.3.medullary space (composed of cancellous or medullary space (composed of cancellous or spongy bone)spongy bone)

OSTEOMYELITIS:OSTEOMYELITIS: Denotes inflammation of bones and Denotes inflammation of bones and

marrow.marrow.• May be a May be a complicationcomplication of any of any

systemic systemic infection but frequently infection but frequently manifests as a manifests as a primaryprimary solitary solitary focus of disease.focus of disease.

• PYOGENIC OSTEOMYELITIS:PYOGENIC OSTEOMYELITIS:

is almost always caused by bacteria.is almost always caused by bacteria.

1.1. Hematogenous spread.Hematogenous spread.

2.2. Extension from a contiguous site.Extension from a contiguous site.

3.3. Direct implantation.Direct implantation.

4.4. E.coli and Pseudomonas.E.coli and Pseudomonas.

5.5. Mixed bacterial infections.Mixed bacterial infections.

6.6. Salmonella infections.Salmonella infections.

• Clinical Course:Clinical Course:

• Fever ,chills, malaise, marked to Fever ,chills, malaise, marked to intense throbbing pain over the intense throbbing pain over the affected region.affected region.

Diagnosis;Diagnosis;

• Sign/symptoms.Sign/symptoms.

• X-rayX-ray

• Blood culturesBlood cultures

• biopsybiopsy

ComplicationsComplications::

• Pathologic fracture.Pathologic fracture.

• Secondary amyloidosisSecondary amyloidosis

• EndocarditisEndocarditis

• SepsisSepsis

• Squamous cell carcinoma.Squamous cell carcinoma.

Tuberculous osteomyelitisTuberculous osteomyelitis::

Routes of entry;Routes of entry;

• Usually blood borne and originate Usually blood borne and originate from a focus of active visceral from a focus of active visceral disease.disease.

• Direct extension (e.g. from a Direct extension (e.g. from a pulmonary focus into a rib or from pulmonary focus into a rib or from tracheobronchial nodes into adjacent tracheobronchial nodes into adjacent vertebrae) or spread via draining vertebrae) or spread via draining lymphatics.lymphatics.

Bone tumorsBone tumors

Classification of primary tumors involving Classification of primary tumors involving bones:bones:

• Bone Forming tumors.Bone Forming tumors.

• Cartilage forming tumors.Cartilage forming tumors.

• Fibrous and fibro-osseous tumors.Fibrous and fibro-osseous tumors.

• Miscellaneous tumors.Miscellaneous tumors.

ArthritisArthritis

• Suppurative ArthritisSuppurative Arthritis

• Tuberculous ArthritisTuberculous Arthritis

• OsteoarthritisOsteoarthritis

• Gout ArthritisGout Arthritis

• Rheumatoid ArthritisRheumatoid Arthritis

ARTHRITISARTHRITIS

• Suppurative arthritis:Suppurative arthritis:

• Due to seeding of joint during bacteremia, most Due to seeding of joint during bacteremia, most commonly due to commonly due to StaphylococcusStaphylococcus, , StreptococcusStreptococcus, , gram negative rods; rarely syphilisgram negative rods; rarely syphilis

• Also due to postsurgical infectionAlso due to postsurgical infection• Neonates:Neonates: often due to osteomyelitis often due to osteomyelitis• Young women:Young women: most commonly due to most commonly due to

gonorrhea (gram negative intracellular diplococci, gonorrhea (gram negative intracellular diplococci, which is associated with multiple joint which is associated with multiple joint involvement, including the knee)involvement, including the knee)

• Sickle cell disease:Sickle cell disease: Salmonella Salmonella

ARTHRITISARTHRITIS

• Tuberculous arthritis:Tuberculous arthritis:

• Insidious onset ofInsidious onset of chronic progressive arthritis, chronic progressive arthritis, usually monoarticular in knee and hip; usually after usually monoarticular in knee and hip; usually after osteomyelitisosteomyelitis

• Leads to fibrous ankylosis of joint with obliteration Leads to fibrous ankylosis of joint with obliteration of joint spaceof joint space

• Can detect from culture and examination of Can detect from culture and examination of synovial fluid.synovial fluid.

• PCR is sensitive; apparent false positives in PCR is sensitive; apparent false positives in clinically negative patients may represent early clinically negative patients may represent early disease. disease.

ARTHRITISARTHRITIS

Degenerative joint disease:Degenerative joint disease:

• Also called osteoarthritis. Also called osteoarthritis. • Nonneoplastic disorder of progressive erosion of Nonneoplastic disorder of progressive erosion of

articular cartilage associated with aging, trauma, articular cartilage associated with aging, trauma, occupational injury.occupational injury.

• Usually age 50+ years (present in 80% at age 65 Usually age 50+ years (present in 80% at age 65 years)years)

• Cartilage degradation may be mediated by IL-1.Cartilage degradation may be mediated by IL-1.• Sites:Sites: men-hips, women-knees and hands; also men-hips, women-knees and hands; also

first metatarsophalangeal joint, lumbar spine; first metatarsophalangeal joint, lumbar spine; usually one joint or same joint bilaterally, at least usually one joint or same joint bilaterally, at least initiallyinitially

OsteoarthritisOsteoarthritis

• Symptoms:Symptoms: pain worse with use of joint, pain worse with use of joint, crepitus, limited range of motion, nerve root crepitus, limited range of motion, nerve root compression; Heberden nodes in fingers of compression; Heberden nodes in fingers of women only (osteophytes at DIP joints)women only (osteophytes at DIP joints)

• Secondary degenerative joint disease:Secondary degenerative joint disease: younger patients with predisposing younger patients with predisposing condition (trauma, congenital, diabetes, condition (trauma, congenital, diabetes, obesity, ochronosis, hemochromatosis), obesity, ochronosis, hemochromatosis), such as knees of basketball playerssuch as knees of basketball players

OsteoarthritisOsteoarthritis

• GrossGross:: early changes are even degeneration of early changes are even degeneration of hyaline cartilage of articular surface, with hyaline cartilage of articular surface, with fragmentationfragmentation

• later thinninglater thinning of cartilage and articular surface of cartilage and articular surface is often soft and granular with altered shape, is often soft and granular with altered shape, sloughing of cartilage .sloughing of cartilage .

cysts:cysts: (synovial fluid forced into fractures via (synovial fluid forced into fractures via ball valve-like mechanism),ball valve-like mechanism),

osteophytes:osteophytes: (bony outgrowths at margins of (bony outgrowths at margins of articular surface) articular surface)

OsteoarthritisOsteoarthritis

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

GOUTGOUT• Gout and gouty arthritisGout and gouty arthritis

• Transient attacks of acute arthritis Transient attacks of acute arthritis initiated by crystallization of urates and initiated by crystallization of urates and neutrophils, followed by chronic gouty neutrophils, followed by chronic gouty arthritis with tophi in joints and urate arthritis with tophi in joints and urate nephropathy nephropathy

• Causes 2-5% of chronic joint diseaseCauses 2-5% of chronic joint disease• Sites:Sites: 50% have initial attack in first 50% have initial attack in first

metatarsophalangeal joint; also ankles, metatarsophalangeal joint; also ankles, heels, knees, wrists, fingers, elbowsheels, knees, wrists, fingers, elbows

GOUTGOUT

• Primary gout (90%):Primary gout (90%): idiopathic (85%) idiopathic (85%) with overproduction of uric acid or known with overproduction of uric acid or known enzyme defects.enzyme defects.

• Secondary gout (10%):Secondary gout (10%): increased increased nucleic acid turnover due to nucleic acid turnover due to leukemia/lymphoma, chronic renal leukemia/lymphoma, chronic renal disease.disease.

GOUTGOUT

• Gout is due to hyperuricemia and Gout is due to hyperuricemia and deposition of monosodium urate crystals deposition of monosodium urate crystals in joints and viscera and uric acid kidney in joints and viscera and uric acid kidney stone formation.stone formation.

• Need serum urate > 7 mg/dl for deposition Need serum urate > 7 mg/dl for deposition (saturation threshold for urate at 98.6 F)(saturation threshold for urate at 98.6 F)

• Risk factors for gout with hyperuricemia Risk factors for gout with hyperuricemia are age > 30 years, familial history of are age > 30 years, familial history of gout, alcohol use, obesity, thiazide gout, alcohol use, obesity, thiazide administration, lead etc.administration, lead etc.

Rheumatoid arthritisRheumatoid arthritis

• Chronic systemic inflammatory disorder affecting Chronic systemic inflammatory disorder affecting synovial lining of joints, bursae and tendon synovial lining of joints, bursae and tendon sheaths; also skin, blood vessels, heart, lungs, sheaths; also skin, blood vessels, heart, lungs, musclesmuscles

• Produces nonsuppurative proliferative synovitis, Produces nonsuppurative proliferative synovitis, may progress to destruction of articular cartilage may progress to destruction of articular cartilage and joint ankylosisand joint ankylosis

• 75% are women, peaks at ages 10-29 years; also 75% are women, peaks at ages 10-29 years; also menopausal womenmenopausal women

• Sites:Sites: small bones of hand affected first (MCP, small bones of hand affected first (MCP, PIP joints of hands and feet), then wrist, elbow, PIP joints of hands and feet), then wrist, elbow, kneeknee

Rheumatoid arthritisRheumatoid arthritis

• X-ray:X-ray: joint joint effusions, erosions effusions, erosions

• narrowing of joint narrowing of joint space; destruction of space; destruction of tendons, ligaments tendons, ligaments and joint capsules and joint capsules produce radial produce radial deviation of wrist, deviation of wrist, ulnar deviation of ulnar deviation of digits, swan neck digits, swan neck finger abnormalitiesfinger abnormalities

Rheumatoid arthritisRheumatoid arthritis

Diagnosis:Diagnosis:

•morning stiffness, arthritis in 3+ joint morning stiffness, arthritis in 3+ joint areasareas

• arthritis in hand joints,arthritis in hand joints,

• symmetric arthritis,symmetric arthritis,

• rheumatoid nodules, rheumatoid rheumatoid nodules, rheumatoid factor, typical radiographic changesfactor, typical radiographic changes

OSTEOPOROSISOSTEOPOROSISIs a term that denotes Is a term that denotes

increased porosity of the increased porosity of the skeleton resulting from skeleton resulting from reduction in the bone reduction in the bone mass.mass.

Primary: Primary:

1- post menopausal1- post menopausal

2- Senile2- Senile

Secondary:Secondary:

1- 1- Endocrine DisordersEndocrine Disorders

Pathophysiology Of Pathophysiology Of OsteoporosisOsteoporosis

AGINGAGING

1- 1- ↓ replicative activity of the osteoprogenitorcells↓ replicative activity of the osteoprogenitorcells

2- ↓ synthetic activity of the osteoblasts.2- ↓ synthetic activity of the osteoblasts.

3- 3- ↓ activity of the matrix bound growth factors.↓ activity of the matrix bound growth factors.Menopause:Menopause:

1- ↓ serum estrogen1- ↓ serum estrogen

2- ↑ IL-1,IL-6 levels2- ↑ IL-1,IL-6 levels

3- ↑ osteoclast activity3- ↑ osteoclast activityGenetic factorsGenetic factorsNutritional effectsNutritional effects

OSTEOPOROSISOSTEOPOROSIS Prevention StrategiesPrevention Strategies• The best long-term approach to osteoporosis is The best long-term approach to osteoporosis is

prevention. prevention.

• children and young adults, particularly children and young adults, particularly women, with a good diet (with enough women, with a good diet (with enough calcium and vitamin D) and get plenty of calcium and vitamin D) and get plenty of exercise, will build up and maintain bone exercise, will build up and maintain bone mass.mass.

• This will provide a good reserve against This will provide a good reserve against bone loss later in life. bone loss later in life.

• Exercise places stress on bones that builds Exercise places stress on bones that builds up bone massup bone mass