Bone infection Bone infection. Osteomylitis Definition:- inflammation of the bone or bone marrow...

Bone Bone infectioninfection

OsteomylitisOsteomylitis

Definition:-Definition:- inflammation of the bone or inflammation of the bone or bone marrow caused by infection.bone marrow caused by infection.

Two types:- Two types:- PyogenicPyogenic T.B osteomylitis T.B osteomylitis

Pyogenic osteomylitisPyogenic osteomylitis

Causetive organisms:-Causetive organisms:-

Staphylococcus aureusStaphylococcus aureus

Age :-Age :-

Infants and childrenInfants and children

Organisms may infect bone through:-Organisms may infect bone through:-

1- Bloodstream, from local areas of infection (as in 1- Bloodstream, from local areas of infection (as in cellulitis).cellulitis).

2- Penetrating trauma e.g joint replacements or 2- Penetrating trauma e.g joint replacements or internal fixation of fractures.internal fixation of fractures.

Pyogenic osteomylitisPyogenic osteomylitis

Site of affection :-Site of affection :-The most common site is tubular bones as they The most common site is tubular bones as they

have the most rapid growth and the largest have the most rapid growth and the largest metaphysismetaphysis

Clinical picture:-Clinical picture:- With acute osteomyelitis, the presenting With acute osteomyelitis, the presenting

complaint is usually local pain, swelling, and complaint is usually local pain, swelling, and warmth, often associated with fever and malaise.warmth, often associated with fever and malaise.

Affect children Affect children

Radiographic Radiographic appearance of appearance of OsteomyleitisOsteomyleitis Radiographic changes after Radiographic changes after

10-14 days after onset of 10-14 days after onset of infection.infection.

Soft tissue swelling ( the Soft tissue swelling ( the earliest sign).earliest sign).

Cortical thickening Irregularity of cortices Sclerosis

Radiographic appearance Radiographic appearance of Osteomyleitisof Osteomyleitis

Bone destruction in the Bone destruction in the metaphysis.metaphysis.

Periosteal reaction, may become Periosteal reaction, may become very extensive and surround the very extensive and surround the bone to form an involucrum.bone to form an involucrum.

Radiographic Radiographic appearance of appearance of OsteomyleitisOsteomyleitis A part of original bone may A part of original bone may

die and form a separate die and form a separate dense fragment called dense fragment called sequestrum.sequestrum.

Radiographic Radiographic appearance of appearance of OsteomyleitisOsteomyleitis

Brodie’s abscess:Brodie’s abscess: It occurs when osteomylitis is partially treated .It occurs when osteomylitis is partially treated . Brodie’s abscess is a spherical region of bone Brodie’s abscess is a spherical region of bone

destruction, filled with pus or connective tissue, destruction, filled with pus or connective tissue, Oval translucency larger than 1cm surrounded by Oval translucency larger than 1cm surrounded by

a heavily reactive sclerosis near end of long a heavily reactive sclerosis near end of long bones (metaphysis).bones (metaphysis).

Small sequestrum may be present.Small sequestrum may be present. Loss of differentiation between the cortex and Loss of differentiation between the cortex and

the medulla.the medulla.

Brodie’s abscessBrodie’s abscess

Typical appearance of a Brodie's abscess is :-

Lucency within the distal metaphysis with surrounding reactive sclerosis.

Role of radionuclide Role of radionuclide imageimage

Much more sensetive for detecting early diseaseMuch more sensetive for detecting early disease Increased uptake after two to three days.Increased uptake after two to three days.

Role of ultrasoundRole of ultrasound

Demonstrate subperiosteal collection of pus well Demonstrate subperiosteal collection of pus well before bone changes on plain x-ray,before bone changes on plain x-ray,

Role of MRIRole of MRI Shows the changes early as bone edema and pus Shows the changes early as bone edema and pus

accumuation.accumuation.

Detect the extent of the infection better than Detect the extent of the infection better than other modalities.other modalities.

Role of CTRole of CT May be used in selected cases to show sequestra May be used in selected cases to show sequestra

How to D.D between How to D.D between osteomyelitis and tumorosteomyelitis and tumor

It is not always possible.It is not always possible. Clinical history .Clinical history . Initial filmsInitial films Ct and MRI , may be better in D.D as they detect Ct and MRI , may be better in D.D as they detect

the lesion better.the lesion better. Biopsy is needed in some cases.Biopsy is needed in some cases.

T.BT.B osteomyelitis osteomyelitis– Spine, followed by large joints.Spine, followed by large joints.– Produce large area of bone destruction.Produce large area of bone destruction.– May be asymptomatic in early changes. May be asymptomatic in early changes.

Alteration of trabecular pattern of bone

Paget’s disease Chronic progressive focal disease of bone.

Characterized by excessive resorption followed by excessive formation of bone, with abnormal bone remodeling.

The bone that is formed is abnormal, enlarged, and prone The bone that is formed is abnormal, enlarged, and prone to fractureto fracture.

This process results in extensive local vascularity and increased fibrous tissue in the bone marrow.

Involvement is usually polyostotic and asymmetric.

Sites of affection :- Pelvis, spine, skull, femur, and tibia.

Paget’s disease Unknown aetiology Eldery patient

Clinical presentation:- Majority are asymptomatic and diagnosed as an

incidental finding Bone pain Fracture Deformity ( bowing ) of long bones

Paget’s diseaseRadiological featuresLong bones:- Cortical thickning Sclerosis Coarsened trabecular pattern Increase size of the bone Bowing of long bone

Paget’s diseaseDense sclerosis involving

the femoral head and neck .

This is a high-risk area for insufficiency fracture.

Paget’s disease Late-stage Paget disease

reveals a transverse fracture through the proximal femoral shaft (banana fracture).

Paget’s diseaseSkull :- A large lytic well defined area (osteoprosis

circumscripta).

Paget’s disease

Paget’s diseaseSkull :-

Many circumscribed patches of sclerotic bone in the calvarium giving a motteled appearance (cotton wool appearance).

Paget’s disease Advanced Paget's

disease of the skull.

Thickened inner and outer tables, new bone deposition (cotton-wool patch(

Paget’s diseaseSpine :- Picture Frame vertebral body

(enlarged square vertebral body with peripheral sclerosis and inner lucency).

Paget’s diseaseSpine :- Densely sclerotic vertebral

body (ivory vertebra)

Paget’s diseasePelvis :- Coarsened trabecular pattern Cortical thickning Enlargment of the pubis and ischium.

Paget’s diseasePatchy sclerosis and

coarsened trabecula characteristic of late-stage Paget disease.

A fracture of the ischium inferior to the acetabulum (arrows) is present.

Paget’s disease

Complications:- Pathological fracture Osteosarcoma

Generalized decrease in bone density (osteopenia)

Osteopenia is a nonspecific radiographic finding Osteopenia is a nonspecific radiographic finding that indicates increased radiolucency of bone .that indicates increased radiolucency of bone .

Bone density may be difficult to assess because Bone density may be difficult to assess because of technical factors (Kvp , mA)of technical factors (Kvp , mA)

Causes of generalized decrease in bone density

(osteopenia)

Osteoprosis Osteomalacia Hyperparathyrodism Multiple myeloma

Osteoprosis

Reduction of calcium content due to deficiency of osteoid (unmineralized portion of the bone matrix unmineralized portion of the bone matrix forms prior to the maturation of bone tissue ) forms prior to the maturation of bone tissue ).

Increase % of fractures especially in the vertebral bodies and hips.

Causes of osteoprosis 1- Idiopathic :- Juvenile. Postmenopausal . Senile .

2- Cushing syndrome and steroid therapy.

3- D.M . 4- Arthritis.

5-Pregnancy.

6- Fracture.

Osteoprosis

Clinical presentation:- Asymptomatic Bone pain Skeletal fracture

Radiographic diagnosis Most commonly seen in the spine.

Overall decrease in bone density except the cortex still clear.

Collapse of the vertebral bodies , so they appearing as wedged or biconcave .

Widened of the intervertebral disc spaces , if Several vertebral bodies are affected.

In long bones, there is thinning of the cortices.

Osteoprosis

OsteoprosisAn osteoporotic spine, showing

compression fractures in the L1 and L3 vertebral bodies.

OsteoprosisTwo views of the lumbar spine

taken 1 year apart demonstrate rapidly developing osteoporosis and multiple compression fractures .

Ricketes Ricketes

Ricketes

Rickets is a softening of bones in children leading Rickets is a softening of bones in children leading to fractures and deformityto fractures and deformity

Occur before epiphyseal closure., It is caused by It is caused by a failure of osteoid to calcifya failure of osteoid to calcify (unmineralized unmineralized portion of the bone matrix forms prior to the portion of the bone matrix forms prior to the maturation of bone tissue )maturation of bone tissue ).

Ricketes Causes of rickets:- Dietery deficiency of vitamine D, or lack of

exposure to sunlight , resulting in decreased production of endogenous vitamine D which is important for absorption of calcium , resulting in resulting in hypocalcemiahypocalcemia

Malabsorption leading to impaired absorption of calcium or vitamine D.

Renal disease where rickets develops despite normal amount of vitamine D (vitamin D resistant rickets).

Chronic renal faliure .

Ricketes Clinical picture :-Clinical picture :- Delayed growthDelayed growth Pain in the spine, pelvis and legsPain in the spine, pelvis and legs Bowed legsBowed legs Abnormally curved spineAbnormally curved spine

Radiological features of ricketes

Commonly seen at the knee,wrists , and ankles.

Fraying and indistinct margins of the metaphysis, causing a cupped appearance

Increased distance between the visible epiphysis and calcified portion of metaphysis.

Ricketes Bowing and curvature of the bones occur

because the undermineralized bone is soft

Bulbous enlargement of the anterior ends of the ribs producing a (ricketry rosary appearance ).

Greenstick fracture is common.

Osteomalacia

Osteomalacia

Occurs in adults due to failure of osteoid to calcify failure of osteoid to calcify .

OsteomalaciaRadiological features Loss of bone density.

Thinning of the cortex.

Bone deformity due to bone softening e.g bowed of the femora and triradiate pelvis (bent inwards).

The vertebral bodies are biconcave.

OsteomalaciaLooser’s zone (pseudofractures) :-Are short lucent bands running through the cortex

at right angles .may have sclertotic margin.

Location :- scapula , femoral necks and pubic rami.

Ostomalacia

Losser’s zone in the femoral neck

Generalized increase in bone density

Generalized increase in bone density

Conditions that cause generalized increase in bone density :-

Sclerotic metastasis Osteopetrosis Myelosclerosis

Osteopetrosis (marble bone disease)

Congenital disorder of bone formation . The bones are densely sclerotic . The bones are brittle and may fracture but heal

easily.

Osteopetrosis

AP and lateral knee in a patient with osteopetrosis

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