MSK Differentials Flashcards

Question

What are the differentials for lucent bone lesion containing calcium or bone

Answer 1

Metastases, enchondroma, chondroblastoma Osteoid osteoma, Osteoblasto Osteosarcoma Fibrous dysplasia, Pagets disease AVN and bone infarction Osteomyelitis Eosinophilic granuloma Intraosseous lipoma

Answer 2

Mets Multiple myeloma Leukemia Ewings sarcoma, Osteosarcoma Lymphoma Chondrosarcoma LCH Acute osteomyelitis

Answer 3

Disuse Sudeks dystrophy Transient osteoporosis of the hip Regional migratory osteoporosis

Answer 4

Osteoporosis Osteomalacia Hyperparathyroidism Diffuse infiltrative bone disease - multiple myeloma, leukaemia

Answer 5

Endocrine - Hypogonadism, Cushing syndrome, DM Acromegaly, Addisons disease Disuse Iatrogenic - Steroids, Heparin Deficiency - Vitamin C deficiency, Protein Idiopathic - young people Congenital - OI, Turners syndrome, NMD

Answer 6

Vitamin D - Dietary, malabsorption Renal disease - Renal osteodystrophy, RTA, Fanconi syndrome Hepatic disease - parenchymal failure, obstructive jaundice Tumour associated

Answer 7

Hypophosphatasia - low serum ALP Biliary atresia Metabolic bone disease of prematurity Hypophosphatasia

Answer 8

Ewings sarcoma Syphillis Infantile cortical hyperostosis

Answer 9

Osteosarcoma Metastases Ewings sarcoma Haemangioma Meningioma TB Tropical ulcer

Answer 10

Aggressive malignant tissue extending into soft tissue Infection

Answer 11

Traumatic Inflammatory Neoplastic - malignant, benign

Answer 12

HOA Pachydermoperiotosis Vascular insufficiency Thyroid acropatchy Fluorosis DISH

Answer 13

Mets OM Arthritides Osteoporosis Osteomalacia NAI Bleeding diatheses Hand-foot syndrome (Sickle cell dactylitis)

Answer 14

Lung - Carcinoma of bronchus, Lymphoma, Abscess, Bronchiectasis, Mets Pleural - pleural fibroma, Mesothelioma Cyanotic congenital heart disease GI - UC, Crohns, Lymphoma, Whipples disease, Coeliac

Answer 15

Steroid therapy and Cushings Neuropathic arthropathy Osteogenesis Imperfecta NAI Renal osteodystrophy Multiple myeloma

Answer 16

Toxic - steroids, alcohol, Immunosuppressives Traumatic - idiopathic, fractures, radiotherapy Inflammatory - RA, SLE, Scleroderma, Infection, Pancreatitis Metabolic and endocrine - pregnancy, DM, Cushings syndrome, Gout Haematopoietic disorders - Haemoglobinopathies, Polycythemia, Gauchers

Answer 17

Normal variant Leukemia Metastatic neuroblastoma Gauchers disease Hurlers syndrome RA Glycogen storage disease

Answer 18

RA Post traumatic osteolysis Multiple myeloma Metastasis Hyperparathyroidism Cleidocranial dysplasia Pyknodysostosis

Answer 19

Neoplastic - metastases, multiple myeloma, chondrosarcoma, Askin tumour Benign - Osteochrondroma, Echondroma, LCH Healed rib fracture Fibrous dysplasia, Pagets disease Brown tumour of hyperparathyroidism Osteomyelitis

Answer 20

Arterial - Coarctation of aorta, Aortic thrombosis, Subclavian obstruction, Pulmonary oligemia Superior vena cava obstruction AVM - Pulmonary or chest wall AVM Neurogenic - Neurofibromatosis

Answer 21

Coarctation proximal to the left subclavian artery

Answer 22

Anomalous right subclavian artery distal to the coarctation

Answer 23

Connective tissue diseases - RA, SLE, Scleroderma, Sjogrens syndrome Metabolic - Hyperparathyroidism Misc - Neurofibromatosis, restrictive lung disease, Poliomyelitis, Marfan's, OI

Answer 24

Chronic anaemias Fibrous dysplasia Pagets disease Healed fractures with callus Achondroplasia Mucopolysaccharidoses

Answer 25

Isolated Dyschondrosteosis Diaphyseal aclasis Turner syndrome Post traumatic or infective

Answer 26

Isolated - Triquetral lunate, capitate hamate, trapezium-trapezoid Syndrome related - Aperts syndrome, Ellis van creveld, Holt Oran syndrome, Turner syndrome Acquired - Inflammatory (RA or JIA), Pyogenic arthritis, Chronic TB arthritis, Post surgical/traumatic

Answer 27

Idiopathic post traumatic Post infarction - Sickle cell Turners syndrome Pseudohyperparathyroidism

Answer 28

Marfans syndrome Homocystinuria

Answer 29

Scleroderma Raynaud's disease Psoriatic arthropathy Neuropathic diseases - DM, Syringomyelia Thermal injuries Hyperprathyroidism Trauma

Answer 30

Acro-osteolysis of Hadju and Cheney Hyperparathyroidism

Answer 31

Psoriatic arthropathy Erosive arthritis Hyperparathyroidism Thermal injuries Scleroderma Multicentric reticulohistiocytosis

Answer 32

Osteomyelitis Metastases (Bronchus) Multiple myeloma ABC GCT

Answer 33

Implantation dermoid/epidermoid cyst Enchondroma Sarcoidosis Glomus tumour Osteoid osteoma Fibrous dysplasia

Answer 34

Benign - ABC, Chondroblastoma, GCT, Simple bone cyst, Fibrous dysplasia Malignant - Telangiectatic osteosarcoma, MFH, Necrotic bone tumour

Answer 35

Metastatic disease Joint disease Traumatic fractures Post surgery up to 1yr Pagets disease Superscan Metabolic bone disease Dental disease Infection

Answer 36

Patient artefact - sweat, injection site Equipment Physiological variants - epiphyses in children, calcification of diverticulation Soft tissue uptake Visualise normal organs - free pertechetate (Thyroid, stomach, salivary glands)

Answer 37

Artefacts (External metal or internal prosthesis or pacemaker) Avascular lesions (cysts) Multiple myeloma Metastases Leukemia Haemangioma of spine

Answer 38

Idiopathic - Infantile, Juvenile, Adolescent Failure of formation - Hemivertebrae, Butterfly vertebrae Failure of segmentation Neuropathic - Tethered cord, syringomyelia, Chiari malformations, Meningocele Neuromuscular disease - Spinal muscular dystrophy, Cerebral palsy

Answer 39

Osteoid osteoma Osteoblastoma Intraspinal tumour Infection

Answer 40

Neoplastic - Metastasis, Multiple myeloma, Lymphoma Osteoporosis Trauma Infection LCH Benign tumours - Haemangioma, GCT, ABC Pagets disease

Answer 41

Osteoporosis Neoplastic disease Trauma Scheuermanns disease Infection LCH Sickle cell anaemia

Answer 42

Metastasis Multiple myeloma Neurofibroma TB Benign bone tumour - ABC or GCT Congenital absence

Answer 43

Osteoblastic metastasis Osteoid osteoma Osteoblastoma Secondary to spondylosis Secondary to congenitally absent or hypo plastic contralateral posterior elements

Answer 44

Generalised - Gigantism, Acromegaly

Answer 45

Pagets disease ABC Haemangioma GCT Hydatid

Answer 46

Ankylosing spondylitis Pagets disease Psoriatic arthropathy Reiters syndrome Rheumatoid arthritis

Answer 47

Klippel-Feil syndrome Isolated congenital failure of segmentation Rheumatoid arthritis Ankylosing spondylitis TB Operative fusion Post traumatic

Answer 48

Metastases Pagets disease Lymphoma Low grade infection Haemangioma

Answer 49

Trauma arthritides - RA, Psoriatic arthritis, JIA, SLE, Ankylosing spondylitis Downs syndrome Morquio syndrome Congenital absence/hypoplasia of odontoid process Retropharyngeal abscess in child

Answer 50

Degenerative spondylosis Alkaptonuria CPPD disease Ankylosing spondylitis JIA Haemochromatosis DISH Gout Idiopathic

Answer 51

Ankylosing spondylitis Alkaptonuria

Answer 52

Reiters syndrome Psoaritatic arthropathy

Answer 53

Stress response

Answer 54

Shear stress across the disc associated with degenerative disc

Answer 55

Tumour in the spinal canal - Ependymoma, Dermoid, Lipoma, Neurofibroma Neurofibromatosis Acromegaly Achondroplasia Communicating hydrocephalus Syringomelia Congenital syndromes - Marfans, Hurlers, Moquio, OI

Answer 56

Aortic aneurysm TB Spondylitis Lymphadenopathy Delayed motor development

Answer 57

Meningomyelocele Intraspinal mass Diastematomyelia Trauma

Answer 58

Prolapsed or sequestrated IVD Mets, Myeloma, Lymphoma deposits Neurofibroma Neuroblastoma/Ganglioneuroma Meningioma Haematoma Abscess Arachnoid cyst

Answer 59

Meningioma Neurofibroma Metastases Subdural empyema

Answer 60

Ependymoma Astrocytoma Dermoid Infarct Haematoma

Answer 61

Trauma OA Crystal induced arthritis - Gout, CPPD, Calcium hydroxyapatite RA Pyogenic arthritis TB PVNS Neuropathic arthropathy Synovial chondromatosis/Amyloid

Answer 62

Inflammatory arthritis

Answer 63

Chondropathic (Degenerative/Metabolic)

Answer 64

Depositional

Answer 65

RA SLE Scleroderma Dermatomyositis

Answer 66

Ankylosing spondylitis Reiters syndrome Psoriatic arthropathy Enteropathic arthritis JIA

Answer 67

OA Neuropathic Haemophilic

Answer 68

Calcium pyrophosphate Haemochromatosis Alkaptonuria Hyperparathyroidism Wilsons disease

Answer 69

Gout Hypercholesterolemia Reticulohistiocytosis Amyloidosis

Answer 70

RA JIA SLE Pyogenic arthritis TB Reiters syndrome Scleroderma Haemophilia

Answer 71

OA CPPD arthropathy Gout Psoriatic arthropathy Ankylosing spondylitis Reiters syndrome Neuropathic arthropathy PVNS

Answer 72

JIA Reiters syndrome Pyogenic arthritis Psoriatic arthropathy RA HPOA Haemophilia AIDS Arthritis

Answer 73

Early infective or inflammatory arthritis Psoriatic arthropathy Acromegaly Gout PVNS

Answer 74

Gout RA PVNS Multicentric reticulohistiocytosis Amyloidosis Sarcoidosis

Answer 75

RA JIA Psoriatic arthropathy Diabetes Leprosy Neuropathic arthropathy Reiters syndrome

Answer 76

Normal variant RA Scleroderma SLE Sarcoidosis Sickle cell disease

Answer 77

Detached osteophyte Osteochondral fracture Osteochondritis dissecans Neuropathic arthropathy Synovial osteochondromatosis

Answer 78

CPPD Hyperparathyroidism Haemochromatosis Alkaptonuria Acromegaly Gout Wilsons disease

Answer 79

Changes in lower/middle 1/3 of joint and iliac side 2. Erosion leading to widened joint space 3. Subchondral sclerosis leads to bony ankylosis

Answer 80

Ankylosing spondylitis IBD Psoriatic arthropathy Osteitis condemns ilii Hyperparathyroidism Paraplegia

Answer 81

Reiters syndrome Psoriatic arthropathy RA Gouty arthritis OA

Answer 82

RA Osteoporosis Osteomalacia and rickets Pagets disease Ankylosing spondylitis OA Psoriatic arthropathy Trauma Familial or idiopathic

Answer 83

Acquired - Pregnancy, Trauma, Osteitis pubis Osteolytis mets Infection Ankylosing spondylitis RA Hyperparathyroidism Congenital

Answer 84

DDH Perthes disease Septic arthritis

Answer 85

Avascular necrosis

Answer 86

Neuromuscular disorders Abductor muscle weakness Cleidocranial dysplasia Diaphyseal atlases JIA Poliomyelitis Femoral neck fracture

Answer 87

Developmental - neuromuscular disorders DDH Fibrous dysplasia Cleidocranial dysplasia RA (Inflammatory) SUFE Femoral neck fracture Perthes disease AVN Renal osteodystrophy Rickets or Pagets disease

Answer 88

JIA Haemophilia Psoriatic arthropathy TB arthritis Rheumatoid arthritis

Answer 89

Neontal - high placental oestrogens Pubertal - excess of oestrogen over testosterone Senile - falling androgen and rising oestrogen levels

Answer 90

Carcinoma of bronchus, gastric, or renal - Secrete HCG Teratoma of testis Cirrhosis Hypogonadism Hypopituitarism

Answer 91

Arterial - Atheroma/aneurysm, diabetes, hyperparathyroidism Nerve - Leprosy, NF Ligament - Tendonitis, AS, Fluorosis Alkaptonuria

Answer 92

Dermatomyositis Polymyositis SLE

Answer 93

Connective tissue disorder - Scleroderma, Dermatomyositis, Polymositis Metabolic - Gout, CPPD, Calcium hydroxyapatite deposition, Tumoral calcinosis Trauma - Myositis ossificans, Haematoma

Answer 94

Parosteal lipoma Haemangioma Synovial osteochondromatosis

Answer 95

Parosteal osteosarcoma Extraskeletal osteosarcoma Synovial sarcoma

Answer 96

Myositis ossificans Surgery Synovial sarcoma Parosteal osteosarcoma Liposarcoma Fibrodysplasia ossificans progressiva

Answer 97

process by which long bones develop their characteristic adult-type appearance. This remodelling results in a cylindrical tubular form. bone being absorbed on one side of the bone and deposited on the other. The diaphyseal narrowing or constriction is a result of bone resorption occurring on the outer periosteal surface and bone formation occurring on the inner endosteal surface at the metaphysis during longitudinal bone growth at the physis.

Answer 98

Osteonesis imperfecta Neurofibromatosis Paralysis Radiation therapy

Answer 99

Gauchers disease Thalassemia Hereditary multiple exostosis

Answer 100

Skull 1. Thickened skull vault. 2. Enlarged paranasal sinuses and mastoids. 3. Enlarged pituitary fossa because of the eosinophilic adenoma. 4. Prognathism (increased angle of mandible). Thorax and spine 1. Increased sagittal diameter of the chest with a kyphosis. 2. Vertebral bodies show an increase in the AP and transverse dimensions with posterior scalloping. Appendicular skeleton 1. Increased width of bones but unaltered cortical thickness. 2. Tufting of the terminal phalanges, giving an ‘arrowhead’ appearance. 3. Prominent muscle attachments. 4. Widened joint spaces – especially the metacarpophalangeal joints: due to cartilage hypertrophy. 5. Premature osteoarthritis. 6. Increased heel pad thickness (> 21.5 mm in female; > 23 mm in male). 7. Generalized osteoporosis.

Answer 101

Axial skeleton 1. Osteoporosis. 2. Intervertebral disc calcification – predominantly in the lumbar spine. 3. Disc-space narrowing with vacuum phenomenon. 4. Marginal osteophytes and end-plate sclerosis. 5. Symphysis pubis – joint-space narrowing, chondrocalcinosis, eburnation and, rarely, bone ankylosis. Appendicular skeleton 1. Large joints show joint-space narrowing, bony sclerosis, articular collapse and fragmentation, and intra-articular loose bodies. 2. Calcification of bursae and tendons. Extraskeletal Ochronotic deposition in other organs may have the following results: 1. Cardiovascular system – atherosclerosis, myocardial infarction, calcification of aortic and mitral valves. 2. Genitourinary system – renal calculi, nephrocalcinosis, prostatic enlargement with calculi. 3. Upper respiratory tract – hoarseness and dyspnoea. 4. Gastrointestinal tract – dysphagia.

Answer 102

(a) Arises in unfused metaphysis or in metaphysis and epiphysis after fusion. (b) Well-defined lucency with thin but intact cortex. (c) Marked expansion (ballooning). (d) Thin internal strands of bone/ trabeculation. (e) ± New bone in the angle between original cortex and the expanded part. (f) (g) Fluid–fluid level(s) on CT and MRI. In the spine they involve the posterior elements. (h) May rarely arise from the surface of bone in a subperiosteal location.

Answer 103

Axial skeleton 1. Involved initially in 70–80%. Initial changes in the sacroiliac joints followed by the thoracolumbar and lumbosacral regions. The entire spine may be involved eventually. 2. The radiological changes in the sacroiliac joints (see 3.12) are present at the time of the earliest spinal changes. MRI most sensitive technique for early disease and all changes except syndesmophytes. 3. Spondylitis – anterior and posterior erosion of vertebral end-plates (Romanus). Enthesitis of annulus fibrosis. Then sclerosis causing ‘shiny corner’ (osteitis). 4. Discovertebral – inflammatory involvement of intervertebral disc (Andersson). 5. Syndesmophytes – bony outgrowths from vertebral margins. 6. Squaring of vertebrae – due to bone proliferation. 7. Arthritis – facet, costovertebral and costotransverse joints (synovitis, erosion, ankylosis). 8. Enthesitis – interspinous ligaments with osteitis. 9. Ankylosis – fusion of spine from 5–7 plus bony extension through 4. Leads to ‘bamboo spine’. 10. Fracture – insufficiency in ankylosed spine (especially cervicothoracic and thoracolumbar junctions). 11. Osteoporosis – with long-standing disease. 12. Kyphosis. 13. Arachnoiditis – rare and late. Arachnoid diverticulae, laminar erosions, dural calcification. Appendicular skeleton 1. Hip – axial migration, concentric joint-space narrowing, cuff-like femoral osteophytes, acetabular protrusion. Symptoms may be dominant, leading to flexion contracture and ankylosis. 2. Shoulder – narrowing of glenohumeral and acromioclavicular joints. Hatchet erosion at greater tuberosity. 3. Knee – tricompartment narrowing and erosion. 4. Hand and foot – asymmetric involvement; small erosion and osseous proliferation. Extraskeletal 1. Iritis in 20% – more frequent with a peripheral arthropathy. 2. Pulmonary disease (a) Restrictive defect due to costotransverse and costosternal joint involvement. (b) Bronchiolitis obliterans organizing pneumonia (BOOP). 3. Heart disease – aortic incompetence, conduction defects and pericarditis. 4. Amyloidosis.

Answer 104

Cartilage calcification (Chondrocalcinosis) Crystal induced acute (Pseudogout) Pyrophposphate arthropathy Associated with hyperparathyroidism and haemochromatosis Marked subchondral collapse and fragmentation with multiple loose bodies simulating a neuropathic joint Pyrophosphate arthropathy is most common in the knee, wrist, metacarpophalangeal joint and acromioclavicular joint. Cartilage loss, subchondral plate sclerosis and subchondral cyst formation. - Unusual intra-articular and articular distribution - Marked subchondral collapse and fragmentation with multiple loose bodies

Answer 105

(a) Arises in the epiphysis prior to fusion and may expand to involve the metaphysis. (b) Well-defined lucency with a thin sclerotic rim. (c) Internal calcification in 60%. (d) Florid surrounding marrow oedema on MRI and can rarely show fluid–fluid levels.

Answer 106

(a) Metaphyseal ± extension into epiphysis, but never only in the epiphysis. (b) Round or oval, well-defined lucency with a sclerotic rim. (c) Eccentric expansion. (d) Internal calcification is uncommon, occasional septation.

Answer 107

Central - Femur, humerus, pelvis (a) Metaphyseal or diaphyseal. (b) Lucent, expansile lesion ± chondroid matrix. (c) Endosteal cortical thickening or thinning. (d) ± Cortical destruction and a soft-tissue mass. (e) ‘Pop-corn’, ‘ring and arc’ or ‘dot and comma’ internal calcification. Peripheral - Pelvic and shoulder girdle, upper femur, and humerus (a) Soft-tissue mass, often arising from the cartilage tip of an osteochondroma. A cartilage cap > 2 cm in thickness, as measured by US, CT or MRI, is considered suspicious of malignant change. (b) Multiple calcific densities. (c) Ill-defined margins. (d) In the later stages, destruction of underlying bone.

Answer 108

Skull 1. Brachycephaly, wormian bones, frontal and parietal bossing. 2. Wide sutures and fontanelles with delayed closure. 3. Broad mandible, small facial bones, delayed eruption and supernumerary teeth. 4. Platybasia. Thorax 1. Aplasia or hypoplasia of the clavicles, more commonly in the lateral two-thirds. 2. Small, deformed scapulae. Pelvis Absent or delayed ossification of the pubic bones, producing apparent widening of the symphysis pubis. Appendicular skeleton 1. Short or absent fibulae. 2. Coxa vara or coxa valga. 3. Congenital pseudarthrosis of the femur. 4. Hand (a) Long second and fifth metacarpals; short second and fifth middle phalanges. (b) Cone-shaped epiphyses. (c) Tapered distal phalanges. (d) Supernumerary ossification centres.

Answer 109

ROMPS Renal osteodystrophy Osteopetrosis Metastases, Myelofibrosis Pyknodysostosis Sickle cell disease

Answer 110

Metastases eventually fracture bones Metastases Myeloma Endochondromatosis (Olliers/Maffucci's) Fibrous dysplasia Brown tumours

Answer 111

Politicians aways make grave blunders Plasmacytoma/Large myeloma deposit Anuerysmal bone cyst Metastases Giant cell tumour Brown tumours

Answer 112

LOSE ME Leukemia Osteomyelitis Sarcoma (Osteogenic) Eosinophilic granuloma Metastases (Neuroblastoma) Ewings sarcoma

Answer 113

ACE GIG ABC Chondroblastoma Eosinophilic granuloma GCT Infection Geode

Answer 114

MLML Metastases/Myeloma Lymphoma Myelofibrosis/Macrocystosis Leukemia

Answer 115

SALMON Spinal cord tumour Achondroplasia, Acromegaly Marfans syndrome, Morquiou syndrome Osteogenesis imperfecta NF1

Answer 116

SHIRT Scleroderma Hyperparathyroidism Infection (Osteomyelitis) RA Trauma (Post traumatic osteolysis)

Answer 117

TIPS Turners syndrome Idiopathic, Injury, iatrogenic, infection Pseudohyperparathyroidism/Pseudopseudohyperparathyroidism Sickle cell disease (Post dactylitis)

Answer 118

SPINACH Scleroderma Psoriasis Injury (Frostbite, burns), infection Neuropathy (Diabetes, Leprosy) Congenital (Hadj-Cheneys syndrome) Hyperparathyroidism

Answer 119

PROBING Pagets disease Rickets Osteogenesis imperfecta Blount's disease Idiopathic NF1 Abnormal growth (Achondroplasia)

Answer 120

Healthy people take vitamins HOA (Secondary) Pachydermoperiostosis (Primary HOA) Thyroid acropachy Venous insufficiency

Answer 121

SAD GITS Steroids Alcohol Diabetes Gauchers disease Infection Inflammation, Idiopathic Trauma Sickle cell anaemia

Answer 122

1. Growth retardation in children. 2. Osteoporosis. 3. Pathological fractures which show excessive callus formation during healing; vertebral end-plate fractures, in particular, show prominent bone condensation. 4. Avascular necrosis of bone. 5. Increased incidence of infection – including osteomyelitis and septic arthritis (the knee is affected most frequently). 6. Hypertension. 7. Water retention resulting in oedema.

Answer 123

(a) Diaphyseal or diametaphyseal. (b) Well-defined lucency (1–2 cm) with a thin sclerotic rim. (c) Expansion of the cortex without cortical breach, scalloping of inner cortex. (d) Internal ground-glass appearance ± calcification/ chondroid matrix. (e) Pathological fracture – a frequent presenting complaint of enchondromas of the hands or feet.

Answer 124

1. Ollier’s disease – multiple enchondromas; tubular long bones ± hands, feet, pelvis. 5–30% sarcomatous transformation. 2. Maffucci’s syndrome – enchondromas + soft-tissue haemangiomas.

Answer 125

(a) Diaphyseal or, less commonly, metaphyseal. (b) Ill-defined medullary destruction. (c) ± Small areas of new bone formation. (d) Periosteal reaction – lamellated (onion skin), Codman’s angle or ‘sunray’ speculation. (e) Saucerization of the cortex due to periosteal destruction. (f) (g) (h) Soft-tissue extension (best appreciated on MRI). Metastases to other bones and lungs. FDG/PET superior to bone scintigraphy in detection of bone metastases.

Answer 126

(a) A cyst-like lesion in the diaphysis or metaphysis with endosteal scalloping ± bone expansion. No periosteal new bone. The epiphysis is only involved after fusion. Thick sclerotic border: ‘rind’ sign. Internally the lesion shows a ground-glass appearance ± irregular calcifications together with irregular sclerotic areas. (b) Bone deformity, e.g. shepherd’s crook deformity of the proximal femur. (c) Growth disparity. (d) Accelerated bone maturation. (e) Skull shows mixed lucencies and sclerosis, mainly on the convexity of the calvarium and the floor of the anterior fossa. (f) Leontiasis ossea is a sclerosing form affecting the face ± the skull base and producing leonine facies. In such cases extracranial lesions are rare. Involvement may be asymmetrical.

Answer 127

(a) Epiphyseal and metaphyseal, i.e. subarticular. (b) A lucency with an ill-defined endosteal margin. (c) Eccentric expansion ± cortical destruction and soft-tissue extension. (d) Cortical ridges or internal septa produce a multilocular appearance. (e) (f) Fluid levels on CT or MRI. 30% local recurrence rate and, rarely, pulmonary metastases.

Answer 128

1. Monoarticular or oligoarticular 2. 1st MTP, inter tarsal joints, ankle, knees 3. Soft tissue swelling and joint effusion during acute attack 4. Eccentric, asymmetrical nodular deposits of calcium urate (tophi) in the synovium, subchondral bone, helix of the ear and in the soft tissues of the elbow, hand, foot, knee and forearm. 5. Joint space preserved until late in disease 6. Bony erosions are produced by tophaceous deposits and may be intra-articular, periarticular or well away from the joint. Round or oval, sclerotic margin 7. Renal disease - urate nephropathy

Answer 129

(a) Vertebra – coarse vertical striations, usually affecting only the body but the appendages are, uncommonly, also involved. (b) Skull – radial spiculation (‘sunburst’) within a well-defined vault lucency. ‘Hair-on-end’ appearance in tangential views. (c) High signal on T1W and T2W MRI because of high fat content.

Answer 130

1. Osteoporosis. 2. Chondrocalcinosis – due to calcium pyrophosphate dihydrate deposition (q.v.). 3. Arthropathy – resembles the arthropathy of calcium pyrophosphate deposition disease. Distinctive beak-like osteophytes. 4. Liver fibrosis and cirrhosis 5. Mottled increased density of liver and spleen (CT), reduced signal intensity (MRI)

Answer 131

1. Knee, elbow, ankle, hip and shoulder are most frequently affected. 2. Soft-tissue swelling due to haemarthrosis, which may appear to be unusually dense owing to the presence of haemosiderin in the chronically thickened synovium. 3. Periarticular osteoporosis. 4. Erosion of articular surfaces, with subchondral cysts. 5. Preservation of joint space until late; ankylosis. 6. Epiphyseal overgrowth; leg-length discrepancies. 7. Knee – squaring of patella, widening of intercondylar notch and epiphyseal overgrowth. 1. Osteonecrosis – especially in the femoral head and talus. 2. Haemophilic pseudotumour – in the ilium, femur and tibia most frequently (a) Intraosseous – a well-defined medullary lucency with a sclerotic margin. It may breach the cortex. ± Periosteal reaction and soft-tissue component. (b) Subperiosteal–periosteal reaction with pressure resorption of the cortex and a soft-tissue mass. 3. Fractures – secondary to osteoporosis.

Answer 132

1. Mental defect (60%). 2. Tall stature, slim build and arachnodactyly, with a morphological resemblance to Marfan’s syndrome. 3. Pectus excavatum or carinatum, kyphoscoliosis, genu valgum and pes cavus. 4. Osteoporosis. 5. Medial degeneration of the aorta and elastic arteries. 6. Arterial and venous thromboses. 7. Lens subluxation – usually downward.

Answer 133

1. Scaphocephalic macrocephaly. 2. J-shaped sella (prominent sulcus chiasmatus). 3. Hydrocephalus 4. Oval vertebral bodies with anterioinferior beak 5. Kyphosis and thoracolumbar gibbous 6. Posterior scalloping with widened interpedicular distance 7. Thickened diaphysis

Answer 134

1. Osteopenia 2. Subperiosteal bone resorption - mainly radial side of middle phalanx of middle finger 3. Diffuse cortical change 4. Brown tumours 5. Bone softening 6. Calcification in soft tissues 7. Marginal joint erosions 8. Weakened subarticular bone 9. Chondrocalcinosis 10. Periarticular calcification 11. Nephrocalcinosis

Answer 135

1. Short stature, dry skin, alopecia, tetany ± mental retardation. 2. Skeletal changes affecting the entire skeleton. 3. Minimal, generalized increased density of the skeleton, but especially affecting the metaphyses. 4. Calcification of paraspinal ligaments (secondary to elevation of plasma phosphate, which combines with calcium, resulting in heterotopic calcium phosphate deposits). 5. Basal ganglia calcification – uncommon.

Answer 136

Neonatal form - Irregular lack of metaphyseal mineralization affecting especially the wrists, knees and costochondral junctions. Infantile form (a) Cupped and frayed metaphyses with widened growth plates. (b) Demineralized epiphyses. (c) Defective mineralization of skull, including sutures which appear widened. (d) Premature sutural fusion; → craniostenosis with brachycephaly. Childhood Mild rickets No craniostenosis

Answer 137

1. Delayed appearance of ossification centres 2. Delayed epiphyseal closure. 3. Short long bones with slender shafts, endosteal thickening and dense metaphyseal bands. 4. Coxa vara with shortened femoral neck and elevated greater trochanter. 5. Brachycephaly. 6. Multiple wormian bones. 7. Delayed development of vascular markings and diploic differentiation. 8. Delayed sutural closure. 9. Kyphosis at the thoracolumbar junction, usually associated with a hypoplastic or ‘bullet-shaped’ body of LV1 or LV2.

Answer 138

1. Joint effusion – early finding. 2. Periarticular soft-tissue swelling – early finding. 3. Osteopenia – juxta-articular, diffuse or band-like in the metaphyses, the latter particularly in the distal femur, proximal tibia, distal radius and distal tibia. 4. Periostitis – common. Mainly periarticular in the phalanges, metacarpals and metatarsals, but when diaphyseal will eventually result in enlarged rectangular tubular bones. 5. Growth disturbances – epiphyseal overgrowth; premature fusion of growth plates; short broad phalanges, metacarpals and metatarsals; hypoplasia of the temporomandibular joint; micrognathia; leg-length discrepancy. 6. Subluxation and dislocation – common in the wrist and hip. Atlantoaxial subluxation is most frequent in seropositive juvenile- onset rheumatoid arthritis. Protrusio acetabuli of the hip. 7. Bony erosions – late manifestation; predominantly knees, hands and feet. 8. Joint-space narrowing – 9. Bony ankylosis – late manifestations due to cartilage loss. late finding; especially carpus, tarsus and cervical spine. 10. Epiphyseal compression fractures. 11. Lymphoedema.

Answer 139

(a) Well-defined lucency in the medulla ± thin sclerotic rim. ± Endosteal scalloping. True expansion is uncommon except in ribs and vertebral bodies. ± Overlying periosteal reaction. (b) (c) Multilocular lucency, without expansion, in the pelvis. Punched-out lucencies in the skull vault with little or no surrounding sclerosis. May coalesce to give a ‘geographical skull’. (d) Destructive lesions in the skull base, mastoids, sella or mandible (‘floating teeth’). (e) Vertebra plana, with intact intervertebral discs. (a) Multiple nodules which cavitate. (b) May be complicated by pneumothorax and pleural effusion

Answer 140

Patterns of bone involvement are (a) Predominantly osteolytic. (b) Mixed lytic and sclerotic. (c) Predominantly sclerotic – de novo or following radiotherapy to a lytic lesion. (d) ‘Moth-eaten’ – characteristic of round cell malignancies. In addition, the spine may show (a) Anterior erosion of a vertebral body caused by involvement of an adjacent paravertebral lymph node. (b) Solitary dense vertebral body (ivory vertebra). 5. Hypertrophic osteoarthropathy.

Answer 141

Axial skeleton 1. Platyspondyly with central anterior protrusion (‘tongues’ rather than ‘beaks’). Similar appearances may be found in pseudoachondroplasia. 2. Hypoplastic dens with atlantoaxial instability. 3. Hypoplastic dorsolumbar vertebra which may be displaced posteriorly and associated with gibbous deformity. 4. Flared iliac wings; shallow acetabula with deficient superolateral margins. Appendicular skeleton 1. Defective irregular ossification of the femoral capital epiphyses leading to flattening. 2. Genu and coxa valga. 3. Short, wide tubular bones (including ribs) with irregular metaphyses. Proximal tapering or rounding of the metacarpals. 4. Irregular carpal and tarsal bones.

Answer 142

1. A well-defined, grossly expansile bone lesion arising, most commonly, in the spine, pelvis or ribs. 2. It may also exhibit soft-tissue extension, internal septa or pathological fracture. 3. Extramedullary plasmacytomas rare. 4. Absence of hypercalcaemia, renal insufficiency, anaemia; normal skeletal survey and normal paraprotein levels.

Answer 143

Diffuse skeletal involvement (myelomatosis). Multiple osteolytic lesions usually (a) Widely disseminated at the time of diagnosis (spine, pelvis, skull, ribs and shafts of long bones). (b) Uniform in size (cf. metastases, which are usually of varying size). (c) (d) Well-defined, subcortical with a narrow zone of transition. Vertebral body collapse, occasionally with disc destruction. ± Paravertebral shadow. Involvement of pedicles is late. (e) Rib lesions tend to be expansile and associated with extrapleural soft-tissue masses.

Answer 144

1. Sclerosis and fragmentation. 2. Joint destruction and disorganization. Subluxation and dislocation. 3. Ligament laxity. 4. Joint effusion. 5. Osteophyte formation 6. Bone resorption may be large in hypertrophic subtype. predominates in atrophic subtype. 7. Bone density preserved. 8. Fractures e.g. posterior calcaneum and second metatarsal in diabetes. 9. Callus tissue excessive. 10. Variable progression, but often rapid. In the early stages can resemble osteoarthritis. 11. Spinal neuropathic arthropathy requires distinction from osteomyelitis and metastasis.

Answer 145

(a) Diametaphyseal, becoming diaphyseal as the bone grows. (b) Well-defined lucency with a sclerotic margin. Increasing sclerosis as lesion matures. (c) Eccentric ± slight expansion; in thin bones, e.g. fibula, it occupies the entire width of the bone. May present with pathological fracture.

Answer 146

(a) Well-defined lucency with a sclerotic rim. (b) May be expansile, but the cortex is preserved. (c) ± Internal calcification. (d) May be purely sclerotic in the spine. (e) In long bones it is metaphyseal or diaphyseal.

Answer 147

(a) Metaphyseal. (b) Well-defined eccentric protrusion with the parent cortex and trabeculae continuous with that of the tumour. (c) Tumour is usually directed away from the end of the bone and migrates away from the end as growth proceeds. (d) The cartilage cap is not visible in childhood, but becomes calcified in the adult. (e) If large → failure of correct modelling.

Answer 148

(a) Cortical (i) Central lucent nidus (< 1 cm) ± dense calcified centre. (ii) Dense surrounding bone. (iii) Eccentric bone expansion ± periosteal reaction. (b) Cancellous (i) Usually femoral neck. (ii) Lucent lesion with bone sclerosis a distance away. The head and neck may be osteoporotic.

Answer 149

1. Decreased bone density. 2. Looser’s zones (pseudofracture) – bilaterally symmetrical lucent bands perpendicular to cortex of uncalcified osteoid. 3. Coarsening of the trabecular pattern with ill-defined trabeculae. 4. Bone softening protrusio acetabuli

Answer 150

1. Increasing bone sclerosis and transverse metaphyseal bands 2. Bone within bone appearance 3. Rugger jersey spine 4. Flask shaped ends of the long bones

Answer 151

(a) Metaphyseal; epiphyseal (< 1%) and diaphyseal (10%) are unusual. (b) (c) (d) (e) May be predominantly lytic, sclerotic or mixed. Wide zone of transition with normal bone. Cortical destruction with soft-tissue extension. ± Internal calcification of bone. (f) Periosteal reaction – ‘sunray’ spiculation, lamellated and/or Codman’s triangle

Answer 152

Active (osteolytic) 1. Skull – osteoporosis circumscripta, especially in the frontal and occipital bones. 2. Long bones – a well-defined, advancing radiolucency with a V-shaped margin which begins subarticularly. Osteolytic and osteosclerotic 1. Skull – osteoporosis circumscripta with focal areas of bone sclerosis. 2. Pelvis – mixed osteolytic and osteosclerotic areas; thickening and sclerosis of iliopectineal and ischiopubic lines. 3. Long bones – epiphyseal and metaphyseal sclerosis with diaphyseal lucency. Inactive (osteosclerotic) 1. Skull – thickened vault. ‘Cotton wool’ areas of sclerotic bone. The facial bones are not commonly affected (cf. fibrous dysplasia). 2. Spine – especially the lumbar spine. Enlargement of vertebrae and coarsened trabeculae. Cortical thickening produces the ‘picture frame’ vertebral body. Ivory vertebra. 3. Pelvis – widening and coarsened trabeculation of the pelvic ring, with splitting of the iliopectineal line may progress to widespread changes in the pelvis which are commonly asymmetrical. 4. Long bones – sclerosis due to coarsened, thickened trabeculae. Cortical thickening with encroachment on the medullary canal. The epiphyseal region is nearly always involved.

Answer 153

1. The epiphysis appears small and sclerotic and the joint space may be widened. Demineralization is seen, particularly in the metaphyseal area of the neck, which may appear rarefied. There is no articular cortex destruction. 2. Later a subchondral fracture may be seen as a radiolucent crescent. A subcortical fracture may be seen on the anterior articular surface (frog lateral view). 3. Femoral neck cysts may be seen. 4. Fragmentation develops and this may lead to coxa plana. 5. Femoral head remodelling leads to coxa magna. 6. Delayed bony maturation may occur.

Answer 154

(a) Normal or periarticular soft-tissue swelling. (b) Bone density preserved. (c) Joint space preserved until late in the disease. (d) Absence of calcification (e) Well-defined erosions on both sides of the joints. (f) Erosions are more prominent when joint capsule is tight (e.g. hip). 6. MRI (a) Diffuse nodular thickening of the synovium with low signal intensity due to haemosiderin deposition. (b) Localized intra-articular variant typically affects Hoffa’s fat.

Answer 155

1. Short stature, round face, thickset features, mental retardation and hypocalcaemia. 2. Short fourth and fifth metacarpals and metatarsals. 3. Basal ganglia calcification (50%). 4. Soft-tissue calcification.

Answer 156

1. Short stature, round face, thickset features, mental retardation and hypocalcaemia. 2. Short fourth and fifth metacarpals and metatarsals. 3. Basal ganglia calcification (50%). 4. Soft-tissue calcification. Normal plasma calcium

Answer 157

1. Bone erosion (a) Surface erosion – (b) Enthesitic erosion – 2. Bone proliferation (a) Adjacent to erosions. (b) Periosteal reaction along diaphysis. 3. Preservation of bone density. 4. Axial skeleton involved in 20–40% with sacroiliitis and spondylitis – sacroiliitis is bilateral and asymmetrical. Large erosions with bone proliferation but ankylosis rare. 5. Spondylitis – prominent asymmetrical paravertebral ossification ‘comma shaped’. 6. Joints involved – distal interphalangeal (feet and hands), knee, ankle, PIP joints (feet and hands), metatarsophalangeal, metacarpophalangeal. 7. Dactylitis – sausage digit – digital oedema, arthritis of interphalangeal joint and tenosynovitis. 8. Pencil-in-cup and cup-and-saucer appearances are a consequence of severe erosive changes. Severe erosions give rise to ‘arthritis mutilans’. 9. Distal phalangeal tuft resorption associated with psoriatic nail changes

Answer 158

2. Vertebral sclerosis may be confined to the upper and lower thirds of the bodies – ‘rugger jersey’ spine. 3. Soft-tissue calcification – less common than in adults. 4. Rickets – the epiphyseal plate is less wide and the metaphysis is less cupped than in vitamin D-dependent rickets. 5. Secondary hyperparathyroidism – subperiosteal erosions and a ‘rotting fence-post’ appearance of the femoral necks. ± Slipped upper femoral epiphysis. 6. Delayed skeletal maturation. 7. Terminal tuft erosion 8. Brown tumours

Answer 159

(a) Synovial inflammation and effusion → soft-tissue swelling and widened joint space. (b) Hyperaemia and disuse → juxta-articular osteoporosis; later generalized. (c) Destruction of cartilage by pannus → joint-space narrowing. (d) Pannus destruction of unprotected bone at the insertion of the joint capsule → periarticular erosions. (e) Pannus destruction of subchondral bone → widespread erosions and subchondral cysts. (f) Capsular and ligamentous laxity → subluxation, dislocation and deformity. (g) Fibrous and bony ankylosis. (h) Intra-articular loose bodies; rice bodies visible on MRI. (i) Absence of proliferative bone change. 1. Interstitial pneumonitis and fibrosis (mid and lower zones).

Answer 160

Widened growth plate Fraying, splaying, cupping of the metaphysis Thin bony spur extending from metaphysis to surrounding uncalcified growth plate Indistinct cortex due to uncalcified subperiosteal osteoid 5. Rickety rosary – cupping of the anterior ends of the ribs and, on palpation, abnormally large costochondral junctions. 6. Looser’s zones uncommon in children. 7. Bowing of long bones 8. Biconcave vertebral bodies

Answer 161

Spine involvement is (a) Segmental – thoracic > lumbar and cervical. osteosclerosis, hyperostosis and hypertrophy, especially medial clavicle. (b) Non-specific spondylodiscitis. (c) Osteosclerosis. (d) Paravertebral ossification. Juxta-articular osteoporosis; narrowing with central or marginal erosions. palmoplantar pustulosis and acne.

Answer 162

Lymph node enlargement Micronodules or large nodules with cavitation Coarse linear/reticular pattern with mid/upper zone predilection. (a) Enlarged nutrient foramina in phalanges and, occasionally, metacarpals and metatarsals. (b) Coarse trabeculation, eventually assuming a lacework, reticulated pattern. (c) Larger, well-defined lucencies. (d) Resorption of distal phalanges. (e) Terminal phalangeal sclerosis.

Answer 163

1. Eventually 50% of patients have articular involvement. Fingers, wrists and ankles are commonly affected. 2. Terminal phalangeal resorption is associated with soft-tissue atrophy. 3. Erosions at the distal interphalangeal, first carpometacarpal, metacarpophalangeal and metatarsophalangeal joints.

Answer 164

2. Earliest signs are seen at the knees. 3. Osteoporosis (usually the only sign seen in adults). 4. Loss of epiphyseal density with a pencil-thin cortex (Wimberger’s sign) (a). 5. Dense zone of provisional calcification – due to excessive calcification of osteoid (b). 6. Metaphyseal lucency (Trümmerfeld zone) (c). 7. Metaphyseal corner fractures through the weakened lucent metaphysis (Pelkan spurs), resulting in cupping of the metaphysis (d). 8. Periosteal reaction due to subperiosteal haematoma (e)

Answer 165

Marrow hyperplasia Osteonecrosis Skull – coarse granular osteoporosis with widening of the diploë which spares the occiput below the internal occipital protuberance. ‘Hair-on-end’ appearance Spine – square-shaped compression infarcts of the vertebral end-plates produce characteristic ‘H-shaped’ vertebrae. Extramedullary haemopoiesis adrenals, skin and breasts. Splenic infarction

Answer 166

Appearances (a) Metaphyseal, extending to the epiphyseal plate. It migrates away from the metaphysis with time. (b) Well-defined lucency with a thin sclerotic rim. (c) Usually central. (d) Thinned cortex with slight expansion (never more than the width of the epiphyseal plate). (e) Thin internal septa. (f) Pathological fracture may be associated with the ‘fallen fragment’ sign – a small fragment of bone in the dependent part of the cyst

Answer 167

AP and true lateral films. Initially widening of the physis is seen with or without demineralization. The femoral may then slip posteriorly, so an early slip is best seen on a lateral view. With continued posterior slippage the femoral head may appear smaller with apparent narrowing of the physis. As the slip progresses the femoral head displaces medially and the line of Klein becomes abnormal. Steel’s sign: on AP view metaphysis double density – posterior lip of epiphysis superimposed on metaphysis.

Answer 168

Polyarthritis Osteonecrosis Terminal phalangeal sclerosis and resorption Pleural effusion

Answer 169

(a) Coarse trabecular pattern – ‘cobwebbing’. (b) Marrow expansion. (c) Skull – granular osteoporosis, widening of the diploë, thinning of the outer table and ‘hair-on-end’ appearance. (d) Spine – osteoporosis, exaggerated vertical trabeculae and fish-shaped vertebrae. (e) Ribs, clavicles and tubular bones of the hands and feet show the typical changes of marrow hyperplasia 1. Extramedullary haemopoiesis – including hepatosplenomegaly. 2. Haemosiderosis – e.g. liver, spleen and pancreas

Answer 170

1. Developmental bowing 2. Congenital bowing 3. Rickets 4. Scurvy 5. Blount's disease 6. Fibrous dysplasia 7. Skeletal dysplasia 8. Osteomyelitis 9. Syphillis

Answer 171

Metastases Multiple myeloma Lymphoma LCH Fibrous dysplasia CRMO

Answer 172

Physiologic periosteal reaction Trauma Infection Prostaglandin therapy Caffey disease (Infantile cortical hyperostosis)

Answer 173

Renal osteodystrophy Osteopetrosis Pagets disease

Answer 174

Ankylosing spondylitis IBD arthritis Rheumatoid arthritis Psoriatic arthritis Reactive arthritis Septic arthritis

Answer 175

Rheumatoid arthritis CPPD arthropathy Collagen vascular disease Haemochromatosis

Answer 176

OA Erosive OA Psoriatic arthritis Reactive arthritis RA

Answer 177

Trauma RA Hyperparathyroidism Scleroderma Infection

Answer 178

Multiple myeloma Metastases Trauma Langerhans cell histiocystosis Leukemia/lymphoma Osteomyelitis

Answer 179

Idiopathic Osteogenesis imperfecta Cleidocranial dysostosis Down syndrome Hypothyroidism Rickets

Answer 180

Idiopathic Post traumatic Skeletal dysplasias

Answer 181

ABC SBC Telangiectatic osteosarcoma

Answer 182

Hyperparathyroidism Scleroderma Trauma Psoriasis Hadju Cheney syndrome

Answer 183

Metabolic disorder - Renal osteodystrophy, hyperparathyroidism Osteoblastic metastases Myelofibrosis, SCD Pagets Osteopetrosis

Answer 184

ABC Osteoblastoma TB Metastases LCH

Answer 185

Osteoblastic metastases Pagets disease Lymphoma Macrocytosis Myeloma

Answer 186

GCT (Closed growth plate) Chondroblastoma LCH Osteomyelitis Eosinophilic granuloma

MSK Differentials Flashcards

(213 cards)