Advanced Diagnostic Imaging FULL SUBJECT

Categories of Bone Tumours

• Benign

• Quasimalignant

• Malignant

  • Primary

  • Secondary (metastatic)

Types of Benign Bone Tumours

• Osteochondroma - Heriditary Multiple Exostoses (HME)

• Haemangioma

• Bone Island (enostoma)

Secondary Metastasis

Appearance	Lytic - 75%	Blastic - 15%	Mixed - 10%
Male	Lung	Prostate	Prostate
Female	Breast	Breast	Breast

Primary malignant bone tumours

• Multiple Myeloma - 43% - older

• Osteosarcoma - 20% - young

• Chondrosarcoma - 10% - middle age

• Ewing’s Sarcoma - 7% - young

Multiple Myeloma - Radiological Features

• Bone Scans - Cold spots

• Early Signs = Gross osteoporosis

• Hallmark feature = Punched out lesions (rain drop skull)

• Vertebra Plana = Wrinkled vertebra

• Pedicles will be preserved

• Rarely, sclerotic lesions occur (ivory vertebra)

Solitary myeloma - Radiological Features

• Localised form of plasma cell proliferation

• 70% of solitary plasmacytoma lesions develop into diffuse Multiple Myeloma

• Typically appears as:

  • Geographic

  • Soap bubbled

  • Highly expansile

Solitary myeloma - Common sites

• Mandible

• Ilium

• Vertebrae

• Ribs

• Proximal Femur

• Scapula

Osteosarcoma - Radiological Features

• Classic lesions presents as a permeative or ivory medullary lesion in the metaphysis of a long tubular bone

• Sunburst or sunray periosteal response is characteristic

• Often, Codman’s triangle associated with destructive lesion

• Cortical disruption with soft tissue mass formation - often larger

• peripheral edge of eccentric lobulated mass appear roughened and irregular may be referred to as cumulus cloud

Ewing’s Sarcoma - clinical features

Metastasis:

• Frequently

• Early

• To lung

• To Bone

Ewing’s Sarcoma - Radiological Features

• Diaphyseal

• Laminated Periostitis

• Short spiculated periostitis

• Saucerisation (erosion on outer surface)

Chordoma - Clinical Features

• Arises from notochord remnant tissue

• 1% of primary malignant bone tumours

• Crosses disc spaces

• Slow growing

• Peak in 40-70 y/o

• M 2:1 F

• More calcification = better prognosis

Chordoma - Involved sites

• Axial (majority)

  • Sacrum 50%

  • Sphenoid 35%

  • Spine 15%

• Extra-axial (insanely rare. 7 Reported cases)

  • Pubic ramus

  • Femur

  • Tibia

  • Metatarsal

  • Lung

  • Rib

  • Ulna

Chordoma - Spread

• 15% metastasise (including to bone)``

Non-Hodgkin’s Lymphoma - Clinical Features

• No prior lymph node involvement

• Round cell neoplasm

• 4% of primary malignant bone tumors

• 20-40 y/o

• M 2:1 F

• Dull pain not relieved by rest (vs multiple myeloma which is)

• Patient generally looks surprisingly well

Non-Hodgkin’s Lymphoma - Sites

Sites:

• Knee 40%

• Femur

• Pelvis

• Humerus

• Tibia

• Ribs, scapulae, vertebrae

Non-Hodgkin’s Lymphoma - Radiographic Features

• Diaphyseal

• Lytic

• If present (uncommon periostitis)

• Pathological fractures are common

• Rarely the lesion is sclerotic and mimics blastic lesions

Giant Cell tumour - characteristics

• Quasimalignant - 20% malignant

• Highly vascular connective tissue tumour

• 5% of all primary malignant 

• 15% of all benign bone tumours

Giant Cell tumour - Clinical Features

• 20-40 

• M:F equal

• Benign - M 2:3F

• Malignant - M 3:1 F

• May get large before symptomatic

• Pathological fracture precipitates symptoms

Giant Cell tumour - Sites

• Femur - distal

• Tibia - proximal

• Radius - distal

• Humerus - proximal

• Sacrum is most common spinal site for GCT

Giant Cell tumour - Radiological features

• Epiphyseal

• Lytic

• Expansile

• Subchondral

• 40% soap-bubbly

• Eccentricly located (off to one side of tubule bone)

Osteoma - Characteristics

• Arises in intramembranous bones

• Rarely multiple osteomas are associated with colonic polyposis and soft tissue tumours = Gardner’s syndrome

Osteoma - Clinical features

• Usually asymptomatic

• Male 1:3 Female

• No malignant degeneration

• Excise if symptomatic

Osteoma - Sites

• Skull

• Mandible

Osteoma - radiological features

• Radiopaque

• Skull tables

• Paranasal sinuses

• Mandible

Osteoid Osteoma - Characteristics

• Differentiate from Brodie’s Abscess

Osteoid Osteoma - Clinical Features

• 10-25 y/o

• M 2:1 F

• Painful!!!

• Aching worse with inactivity

• Dramatically relieved by aspirin

Osteoid Osteoma - Sites

• 50% femur and tibia

• Proximal end of femur

• Spine (posterior neural arch)

  • Cervical 27%

  • Thoracic 12%

  • Lumbar 60%

  • Sacral 2%

Osteoid Osteoma - Radiological Features

• Nidus <1cm diameter

• Sclerosis - reactive

• Periostitis depends on location in bone

• Cortical (most common)

• Cancellous (in medullary cavity)

• Subperiosteal (creates strongest periosteal reaction)

Osteoblastoma - characteristics

• 1% of benign bone tumours

• Giant osteoid osteomas

• Histologically similar to osteoid osteoma

• Nidus >1cm (larger than osteoid osteoma)

Osteoblastoma - Clinical Features

• 70% <20 y/o

• M 2:1 F

• Progressive onset of pain

• Spinal lesions produce painful scoliosis

• May cause spinal stenosis

Osteoblastoma - Sites

• Spine - posterior neural arch

• Femur

• Foot

• Ankle

Osteoblastoma - Radiological features

• Scoliosis

• Spinal stenosis

• Expansile

• Radiolucent

• Metaphyseal/diaphyseal in tubular bones

• Mild reactive sclerosis

Enchondroma - Characteristics

• 10% of benign tumors

• Occur in any enchondrally formed bone

• Cartilage cell rests in metaphysis growth

• Most common benign tumour in hand

Enchondroma - Clinical Features

• 10-30 y/o

• M=F

• Usually asymptomatic

• Pathological fracture leads to X-ray leading to discovery

Enchondroma - Sites

• Hands 50%

• Femur

• Humerus

• Ribs

Enchondroma - Radiological Features

• Geography

• Radiolucent

• Expansile

• Metaphyseal

• Endosteal scalloping

• Calcification 50%

Enchondroma - DDx

• Fibrous dysplasia

• Simple Bone Cyst

• Giant Cell Tumour

• Bone infarct (when calcified)

Enchondromatosis - Characteristics

• Ollier’s Disease

• Identical lesions to those of solitary endochondroma

• May see a streaky “celery stick” form involving the metaphyses

• If cavernous soft tissue haemangiomata are present, this constitutes maffucci's syndrome

• Malignant degeneration has been reported in up to 50%

• Closer lesion is to the spine, the more likely it will undergo malignant change

Enchondromatosis - Clinical Features

• Usually asymptomatic

• May have associated deformities

Enchondromatosis - Sites

• Hands

• Feet

• Knee

• Pelvis

• Ribs

Enchondromatosis - Radiology

• As for solitary enchondroma

• Celery stick form is seen in metaphysis

Non-Ossifying Fibroma - Clinical Features

• Non cancerous tumour of connective tissue

• >2cm

• 8-20 year olds

• Asymptomatic unless pathological fracture

• M:F 2:1

Non-Ossifying Fibroma - Common Sites

• Lower extrem

• Distal tibia

• Knee

• Prox humerus

• Fibula

Non-Ossifying Fibroma - Radiographic Features

• Solitary lesion

• Eccentric

• Soap bubbly

• Arises from cortex and expands into medulla

• Metaphyseal

• Sclerotic border

• Narrow zone of transition

Simple Bone Cyst - Clinical Features

• Not really a tumour - fluid filled cyst in a chamber lined with fibrous tissue

• 3% of benign bone tumours

• Unicameral (one room)

• It is usually asymptomatic unless pathological fracture (occurs in ⅔)

• 75% are prox femur or humerus

• Can also be in pelvic and calcaneous

• 3-14

• M 2;1 F

Simple Bone Cyst - Common Sites

• Proximal humerus

• Proximal femur

• Humerus 2:1

• Calcaneus

• Pelvis

• Centrally located

Simple Bone Cyst - Radiographic Features

• Single or multichambered (soap bubbly)

• Geographic

• Radiolucent

• Broad at metaphyseal

• Narrow at diaphyseal

• Expansile

• Endosteal scalloping but not usually wider than metaphysis

• No periosteal response

• No cortex breach

• No soft tissue mass

• Fallen fragment sign in 10% of cases - especially with fracture, a piece of the wall of the cyst falls into the most gravitationally dependent part of the cyst

Aneurysmal Bone Cyst - Clinical Features

• Vessels within not actually aneurysmal, just blood filled cavity - tumour like

• 1% of biopsied tumours

• Most common benign tumour of clavicle

• Young 5-20

• M 2:3 F

• Sudden onset of pain and rapid increase in severity

• Pathological fracture common

• If in spine, can cause paraplegia

• Often hx of trauma

• 80% in long tubular bones and spine

• Femur, tibia, thoracic and lumbar most common

• When spinal - often neural arch (may mimic osteoblastoma)

Aneurysmal Bone Cyst - Sites

• 80% long tubular bones and in the spine

• Femur and tibia most common

• Tx and Lx most common spinal

• Predilection for the neural arch

• metaphyseal, eccentric and can be diaphyseal

Aneurysmal Bone Cyst - Radiographic Features

• Varied presentation

• Eccentric 

• Metaphyseal - expands to epiphysis after growth plate closure (opposite to sbc which grows away) (however ABCs can be diaphyseal)

• Expansile, radiolucent and rapidly growing (mimic malignancy)

• Cortex thins but usually intact

• Periosteal buttressing at edges (like codmans)

• May be soap bubbly, show trabeculae

• Can cross growth plate (rare)

  

Paget’s Disease - Clinical Features

• focal disorder of bone metabolism causing accelerated bone remodelling

• Disease occurs when osteoclasts break down faster than osteoblasts replace it. Might be inflammatory, endocrine autoimmune etc. 

• M:F 2:1

• Rare <40, most>55

• 90% asymptomatic

• Pain can be present if paget’s causes bone deformities or fractures

• Increasing hat size may be noted due to enlargement of calvaria

• Pelvis

• Vertebral body

• Clavicle

• Humerus

• Ribs

• Paget’s is subarticular and extends to involve the entire bone

• High incidence in the UK

Paget’s Disease - Sites

• Pelvis

• Vertebrae

• Clavicle

• Humerus

• Ribs

• Fibula LEAST LIKELY

Paget’s Disease - Complications

• Deformities due to bone softening

• Proximal femur- shepherds crook (coxa vara)

• Tibia - sabre shin deformity (anterior bowing)

• Protrusio acetabili

• Frontal and patietla bossing

• Basilar invagination

• Lentiasis ossei (lyon face)

• Fractures

• Vertebral body expansion leading to stenosis

• Transverse banana - Like fractures of long bones

• Pseudo fractures - lines of demineralisation replaced by fibrous tissue

• Anaemia due to fibrous replacement of bone marrow

• Secondary degenerative changes due to destruction of articular cartilages

• Hypercalcuria (from bone resorption) - urinary calculi - uteric colic pain

• High output cardiac failure (if ⅓ skeleton or more involved)

• Malignant degeneration to osteosarcoma (new pain, increase size) poor prognosis

• Leontiasis ossea of the pelvis

• high output of cardiac failure

• Malignant degeneration relatively rare but possible

• Paget’s Sarcoma - Femur, humerus, innominate, skull, tibia

Paget’s Disease - Pathological Features

• Replacement of normal bone (patternless)

• Pagetic vascular and fibrotic bone

• Been called mosaic structure of Paget’s disease

Paget’s Disease - Radiographic features

• Hot on bone scan

• Skull - early lytic (osteoporosis circumscripta), later cotton wool

• Vertebral involvement: thickened enlarged end plates (squared off appearance) picture frame vertebra

• Ivory vertebra - homogenous increase in radiopacity

• Increased coarsening of trabeculae

• Pelvis - cortical thickening, bone expansion causing thickening of the iliopectineal line which obliterates Kohler’s tear drop + brim or rim sign

Paget’s Disease - Stages

1. Osteolytic

2. Mixed

3. Blastic

4. Malignant

Fibrous Dysplasia - Clinical features

• Fibrous dysplasia is a rare genetic disorder that causes abnormal bone growth

• Replaced by fibrous tissue

• Poorly formed trabeculae

• Begins in medullary

• Monostotic or polyostotic (* McCune-Albright syndrome - associated with cafe au lait spots and endocrine issues - growth hormone excess affects FD bone more than normal bone)

• Asymptomatic so incidence is unknown

• Bowing deformities (shepherds crook) and pathological fractures

• Cafe au lait spots in cost of maigne in 30% polyostotic

Fibrous Dysplasia - Types

• Monostotic - one bone involved

• Polyostotic - two or more involved

Fibrous Dysplasia - Sites

• Monostotic - typically the ribs, tibia, skull

• Polyostotic - femur, skull, tibia,. Humerus, ribs, fibula, radius and ulna

• Vertebral involvement is rare

Fibrous Dysplasia - Radiographic Features

• Skeletal lesions NOT present at birth

• Normal bone replaced by abnormal fibrous tissue

• Cause widening of the medullary cavity, thinning of cortex and endosteal scalloping

• Rarely malignant degeneration to fibrosarcoma or osteosarcoma

• Ground glass appearance (a characteristics hazy, indistinct, or speckled pattern seen on X-rays and CT scans, indicating abnormal boe formation within the affected area)

• Cherubism - cheeks appear bigger due to FD of mandible

• Soap bubbly appearance

• Endosteal scalloping

• Mildly expansile lesion

• Geographic - encapsulated by sclerotic border

• Pathological fracture

• Most radiolucent, soap bubbly, located or trabeculated 

• Ground glass or smokey - trabecular patterns wiped out

• Geographic, encapsulated by sclerotic border

• Bone expansion with widening of medullary canal, endosteal scalloping

• Bone softening

• Expansile rib lesion

• Pseudoarthrosis can occur as a result of pathological fracture and non union

Neurofibromatosis Type 1 - Clinical Features

• Cafe au lait spots (smooth margins - coast of california, not raised)

• Fibroma molluscum (elevated cutaneous fibrous nodule)

• Osseous deeformities and lesions

• (Neurofibroma also present)

• Elephantiasis neuromatosa - thick large soft tissue folds

• Pulsating exophthalmos (temporal lobe herniation through deficient/absent posterior wall of orbit)

• Spinal involvement (includes paraplegia, kyphoscoliosis, altantoaxial subluxation)

• Neurofibromata

• Malignant degeneration to neurofibrosarcoma

• Lesions biopsied multiple times more likely to degenerate sarcoma

Neurofibromatosis Type 1 - Radiographic Features

• 50% have skeletal lesions 

• 50% have kyphoscoliosis (acute angle usually lower thoracic 5-7 vertebrae)

• Posterior vertebral scalloping (intraspinal masses - pressure effect)

• Two types of scalloping

  • Posterocentral scalloping along multiple levels (due to dural extasia ballooning of the dural sheath and trapped CSF associated with herniated nerve root sheaths

  • Eccentric and unilateral - dumbbell shape, half in spinal canal half in IVF (enlarges IVF) see image C1/2

• Twist ribbon appearance (scalloping of rib margins)

• Pseudoarthrosis of the tibia in 50% 

• Multiple large noon ossifying fibromas

• Focal giantism

• Renal artery stenosis

• 1% get adrenal tumour pheochromcytoma and 20% get neurofibromatosis

• Osteomalacia may occur

Battered Child Syndrome - Other names

• Child abuse

• Non-accidental injury

• Parent infant traumatic stress syndrome

• Caffey-Kempe syndrome

Battered Child Syndrome - Clinical Features

• A child with multiple fractures of the long tubular bones and subdural haematoma

• Trauma is usually inflicted by parent, guardian or de facto partner

• Children usually less than 6 years old when brought in for medical attention, and are often less than 2 years old when exposed to trauma

• After age 4, children can either escape the abuser or talk about what is happening

• Any evidence of repeated trauma in a child including bruising, burns should arouse suspicion

• Repeated episodes of multiple fractures are highly suggestive

Battered Child Syndrome - Radiographic features

• Multiple fractures (especially at rubs) at different stages of healing is a hall-mark feature

• Particularly significant are fractures at the corner of metaphyses (especially medial side of distal femoral metaphysis)

• Periosteum loosely attached at the shaft of long bones but more firmly attached to the metaphysis

• Lifting of the periosteum of the shaft (exuberant callous), especially tubular long bones

• Periostitis is seen within 1-2 weeks of injury (helps date the injury)

Battered child Syndrome - Shaking a child sequelae

• Brain damage - intracranial and subdural hematoma

• Retinal detachment

• Spinous process fracture of thoracic and lumbar spine

• Humeral and rib fractures

Dystrophic Calcification (myositis ossificans) - Clinical Features

• Most calcification 95-98% is dystrophic (lacking in form) = small to large amorphous calcification in damaged soft tissue

• Calcification can occur as part of non-specific inflammatory response to tissue damage (trauma, infection, chronic disease, response to medical devices)

• Calcification can progress to ossification - meaning a cortex and medullary space are formed

• Should be called heterotopic ossification

Dystrophic Calcification - Sites

• Elbow - brachialis anterior

• Thigh - quadriceps femoris and adductor muscle

• Knee - medial collateral ligament (pelligrini-Stieda Disease)

• Shoulder - AC ligament rupture

Dystrophic Calcifications - Differentials

• Vascular

  • Venous insufficiency

• Infection

  • Parasitic infestation

  • Cysticercosis

  • Dracunculiasis

  • Armillifer armillatus

• Neoplasm

  • Osteoma

  • Osteosarcoma

  • Tumour

• Drugs

  • Vitamin D

• Autoimmune

  • Dermatomysitis

  • Scleroderma

• Trauma

  • Heterotopic ossification

  • Injection granulomas

  • Necrosis

Thoracic Aorta Aneurysm - Clinical Features

• M 3:1 F

• Peak age 65

• Many asymptomatic

• Found incidentally on chest images

• Symptomatic presentations most commonly are pain in the:

  • Substernal region

  • Back (mid-thoracic)

  • Shoulder

  • Hoarseness (recurrent laryngeal nerve compression)

  • Stridor

  • Dyspnea

  • Dysphagia

  • Facial engorgement (superior vena caval compression)

Thoracic Aorta Aneurysm - Differentiate from age related dilation and tortuosity

Typical senile changes are usually made up of five features:

1. Ascending aorta sweeps to the right

2. Aortic arch lies close to the clavicle

3. Tracheal indentation is more prominent

4. Diameter is enlarged between 3 and 4 cm

5. Descending aorta is tortuous in its course and projects more laterally into the thoracic cavity

Thoracic Aorta Aneurysm - Location suggestions

• Ascending aorta suggests syphilis, Marfan’s Syndrome and AS

• Aortic arch location is associated with atherosclerosis and trauma

• Descending aorta is more commonly involved with trauma and collagen disease

Abdominal Aorta Aneurysm - Clinical Features

• Abdominal aorta most common vessel for aneurysm below the diaphragm

• AAA is probably the most common extraspinal, potentially life-threatening disorder encountered in patients presenting with back pain

• 2-6% of general population

• For every 5 years after the age of 65, the risk increases by 40%

• Males are more frequently as M 5:1 F

Abdominal Aorta Aneurysm - Sites

• Sites of involvement in descending order of incidence are:

  • Abdominal aorta

  • Aortic arch

  • Descending thoracic aorta

  • Ascending aorta

Abdominal Aorta Aneurysm - Risk Factors/incidence

• Known risk factors:

  • Male 

  • >60

  • Hypertension

  • Heart disease

  • Hyperlipidemia

  • Peripheral vascular disease

  • Positive family hx of AAA

• Smoking is the most important risk factor that can be avoided

• 40% of patients have hypertension

• 30% have heart disease

• Almost 30% incidence in male siblings of patients with AAA

Abdominal Aorta Aneurysm - Rupturing

• At least 25% of AAA > 5cm will rupture within 5 years

• Those AAAs under 5cm have a rupture rate of only 5%

• AAA on average expands by 4-5mm each year

• Can cause anterior scalloping in 5%

Vertebral Artery Tortuosity - Clinical Features

• Age-related vertebral arterial wall thinning and elongation precipitates dilation and ectasia

• When symptoms do occur from this altered blood flow to the hindbrain they are often bizarre and clinically confusing

• Called the barre-lieou syndrome, symptoms include headaches, dizziness, nystagmus and suboccipital pain as well as nausea and vomiting

• Occasionally leads to pulsatile transmission to adjacent bony structures which may produce extrinsic bony erosion (Hadley’s erosive defect)

• An Astute diagnostician may recognize the erosive defunct on cervical plain films

• Majority unilateral

• Symptoms occur if radicular compression or rarely if path fracture results from extensive erosion

• Pregnancy may precipitate radicular symptoms

• Bilateral atherosclerotic occlusion of the carotid arteries may precipitate vertebral artery dilation as a compensatory mechanism for maintaining cerebral perfusion

Vascular Calcification

Ricket’s (hypovitaminosis) - General features

• Childhood equivalent of osteomalacia

• Systemic disease of infancy and childhood

• Premature birth is a predisposing factor

• Calcification of bone matrix is deficient

Ricket’s - Clinical Features

• 6 months - 1yo

• Maternal vitamin D prevents manifestations for up to 6 months

• Infant has softened skull bones

• Costochondral junction is enlarged - rachitic rosary

• Limb deformities with epiphyseal swellings are noted

• Infant is irritable and shows increased sweating

Ricket’s - Laboratory

• Serum calcium is normal to low

• Serum phosphorus is slightly low

• Alkaline phosphatase is increased

Ricket’s - Radiographic Features (active)

• Changes at end of long bones - knee, ankle and wrist

• Metaphysis is flared, widened or trumpeted

• Physis is widened 

• Metaphysis appears frayed - brush border

• Bowing deformities

• Greenstick fractures

• Pseudofractures - rare

• Costochondral junction is enlarged

Ricket’s - Radiographic Features (healing)

• Mineralisation of zone of provisional calcification

• Dense metaphyseal band

• Deminerralisation of subperiosteal osteoid tissue

• Mimics periosteal new bone formation

• Calcification of ossification centres appears as a marginal ring

• Changes mimic active scurvy and heavy metal toxicity

Scurvy (Hypovitaminosis D) - General

• Humans are unable to synthesize vitamin C so must get it in their diet

• Ascorbic acid (vitamin C) is much higher in human milk than in cow’s

• Incidence of infantile scurvy low with breast feeding

• In infants = barlow’s disease

Scurvy - Clinical Features

• 6–9 months

• Malaise and weakness

• Perifollicular haemorrhage

• Hyperkerototic papules

• Bleeding

  • Gums

  • Joints

  • Subperiosteally

• Anaemia

• Delayed wound healing

• Loose teeth and mouth infections

• Fever

Scurvy - Laboratory

• Normal plasma ascorbic acid = 0.6 mg%

• <0.2 mg% is a deficiency state

• Deficiency state 3–6 months must be maintained before symptoms occur

Scurvy - Pathology

• Both chondroblastic and osteoblastic activity is disordered

• Changes prevalent where growth is rapid

• Devvelopment and calcification of new cartilage cells occurs normally

• Removal of the calcified cartilage matric is abnormal

• No new inter-cellular matrix is laid down between these new cells

• Ossification fails to occur

• Bones may fracture at metaphyseal sites and not heal

• Blood vessels wall fragility - lack of cementing between endothelial cells

Scurvy - Sites

• Anterior ribs

• Distal femur

• Proximal humerus

• Both ends of the tib and Fib

• Distal radius and Ulna

Scurvy - Radiology

• Dense metaphyseal bands 

• Ground glass appearance

• Halo ossification centre

• Cortical thinning

• Corner sign

• Lateral spurs (pelkan’s spurs)

• Subperiosteal haematomas

• Metaphyseal fractures

• Atrophic scurvy line (trummerfeld zone)

• Soft tissue oedema

• Spinal changes

• Healing

Heavy Metal Poisoning (lead) - Clinical Features

• Infants and children

• History of eating flakes of paint

• Can lead to cerebral edema

• Can be fatal if meninggoencephalitis occurs

• Mortality is 25%

• Can see radiographic changes within 1 month

Lead poisoning - radiology

• Lead lines - dense metaphyseal bands seen at the site of greatest bone turnover

• Lead is metabolised similarly to calcium

• Interferes with normal remodelling to result in the erlenmeyer flask deformity of the femur

• Lead lines reflect:

  • Amount of ingested lead (density of band)

  • Time period of ingestion (thickness of band)

  • Number of periods of ingestion (number of bands)

Dense metaphyseal bands can also be seen in:

• Normal children under 4

• Scurvy

• Healing rickets

• Cretinism (juvenile hypothyroidism)

• Metal intoxications such as:

  • Bismuth

  • Phosporus

  • Mercury (administered as an injection to treat certain disorders

Phosphorus poisoning - General

• Rare nowadays but formerly common as a result of administration of phosphorylated cod liver oil for rickets and tuberculosis

• Produces dense metaphyseal bands 

• Bands fade after ingestion ceases

Radium Poisoning - General

• Caused malignancies arising in bone such as bone sarcomas

Ossified Posterior Longitudinal Ligament Syndrome (OPLLS) - General

• Condition may be associated with compression of the spinal cord

• Definition of ossified posterior longitudinal ligament syndrome diffuse idiopathic skeletal hyperostosis and for this to occur in Japan (Japanese disease)

• Occurs most commonly is Cx and least commonly in Lx

Ossified Posterior Longitudinal Ligament Syndrome - Clinical Features

• Symptoms if present are mostly associated with cervical spine involvement and least frequently in Tx and Lx

• Findings may include insidious onset of motor and sensory deficits mainly of lower limb cord myelopathy is heralded by progressive difficulty walking

• S/S are likely with ossified ligament occupies more than 60% of the sagittal diameter of the cervical spinal canal

Ossified Posterior Longitudinal Ligament Syndrome - Pathology

• Ossified ligament usually spans 3 to 4 adjacent spinal segments

• Microscopically the affected ligament demonstrates superficial well0formed cortical bone but poorly formed marrow cavities

• Normal ligamentous tissue is found in the deeper layers

• Spinal cord changes in OPLL may include flattening of the cord, grey matter infarction and demyelination of the lateral and posterior white columns

Ossified Posterior Longitudinal Ligament Syndrome - Radiology

• Findings best detected on lateral plain film

• Most common in mid and upper Cx

• Dense ligament may be up to 5mm in thickness and parallels to the posterior body margins

• OPLL may be separated from the underlying vertebrae by a radiolucent zone representing normal ligament

• Underlying discs and apophyseal joints are usually unaffected by degenerative change

• 85% of patients with OPLL also have DISH. 50% of DISH have OPLL

• Progressive myelopathy requires decompression laminectomy

Neurotrophic Arthropathy - General

• Advanced DJD

• Seen in patients with impaired proprioception or diminished pain sensation

• Relationship noted between DJD and tabes dorsalis

Neurotrophic Arthropathy - Clinical Features

• Neurotrophic arthropathy was formerly most common due to syphilis but now patients with diabetes mellitus

• Neurotrophic changes in approximately 5% of diabetics

• Changes usually affect ankle and foot in diabetes

• In syphilis 20% of patients develop change affecting lumbar, knee and ankle

• Syringomyelia 25% show neurotrophic change of the upper extremity  shoulder wrist and elbow

• Neurological manifestation associated include wider gait, loss of reflexes and pain insensitivity

• Affected joints may be painless, unstable and or produce crepitus

• Recurrent and painless joint effusion seen early in the condition

• Charcot’s joint may take weeks to years to develop

Neurotrophic Arthropathy - Pathological

• Thought to be as a result of ineffectual neurological protection from mechanical trauma

• Neurovascular theory exists which estimates neurologically mediated increased intraosseous blood flow leads to stimulation of osteaclastic bone resorption

• Resorption leads to fracture and joint damage

• In weight bearing regions, secondary hypertrophic changes are superimposed. Intra-articular cartilage fibrillation and flaking has been found together with cartilaginous and osseous loose bodies