Nutrition, Metabolic, Endocrine Disorders

Question 1

Osteoporosis

Answer 1

• Decreased matrix of bone but normal mineralisation

Types

• General
  
  • Bone density decreased in majority of skeleton
  • Most common: senile and postmenopausal
• Regional
  
  • Single region or segment of body
  • Disuse osteoporosis: reflex sympathetic dytrophy syndrome
• Localised
  
  • Osteoporosis affecting small regions of bone due to local disease
  • Inflmmatory arthrits, neoplsm, infection

Radiographic Features

• Empty box apperance = increased density of thinned endplates with reposption of trabeculae
• Pseudohaemangioma appearence = accentuated vertical vertebrae
• Insufficiency fractures
• Thinned cortices
• Accentuation of Ward’s Triangle (hip)
• Decreased bone density

Question 2

Osteomalacia

Answer 2

Normal bone quantity but decreased mineralisation

• Linked to problems with low Vitamin D, calciun, phosporus metabolism
• Decreased bone density
• Soft bone deformities
  
  • Protrussio acetabuli
  • genu varum
  • bowing of long bones
  • kyphoscoliosis
  • increased endplate concavity
• Coarse trabecular pattern (mottled, hooney comb appearance)
• Loss of cortical definition
• Psuedofractures (femoral neck, pubic and ischial rami, ribs, lateral margin of scap)

Question 3

Rickets

Answer 3

Childhood equivalent of osteomalacia

• Inadeqaute vitamin D
• Inadeqaute sinlight
• Intestional malabsorption
• Renal tubular defects
• Develops berween 6 months and 1 year old
• Widened growth plates, frayed and cupped (paintbrush) metaphyses, absent zone of peripheral calcification
• Rachitic Rosary = bulbous enlargment of costochondral junctions with cupped anterior rib ends

Question 4

Hyperparathroidism

Answer 4

Overactivity of the parathyroid gland resulting in osteoclastic parathyroid hormone (incresed resorption of bone)

• Primary
  
  • Increased parathyroid hormone due to adenoma, hyperplasia, carcinoma
  • Females 3:1
  • 50 years
• Secondary
  
  • Chronic renal disease results in hypocalcaemia prmoting increased parathyroid secretion
• Tertiary
  
  • Parathyroid gland strops repsonding to serum calcium levels and begins working independently
  • Often a result in haemodialysis

Radiographic features

• Osteoclastic resporption with fibrous tissue replacment
• Accentuated tabeculae, lack of cortical definition, endosteal resorption, intracortical tunneling
• Subperiosteal resporption of outer cortex
  
  • Outer cortical erosion, giving irregular, frayed, lace like appearence
  • Radila margins middle and proximal phalanges of 2nd and 3rd digit of the hand
  • Medial metaphysis humerus and tibia
  • Undersurface of distal clavicle, trochanters, tuberosities
  • Tufts of distal phalanges
• Osteolysis and widened joint spaces
• Salt and pepper skull
• Loss of cortical definition
• Brown tumours (Osteoclastoma)
  
  • Distinct radio lucent lesions that are geographic, slightly expansives, lightly seperated
• Rugger Jersey Sign in vertebrae
  
  • Uniform subendplate sclerosis
  • DDx Osteopetrosis (Higher contrast)

Increased AC joint space (MSHIRT)

• M = metasteses
• S = scleroderma
• H = Hyperparathyroidism
• I = Infection
• R = RA
• T = Trauma

Question 5

Sickle Cell Anaemia

Answer 5

• A severe chronic incurable haemolytic anemic condition that occurs in people homozygous for hemoglobin S (HbS-S).
• An abnormal molecular structure of hemoglobin results in the “sickle” distortion of red blood cells.

Pathophysiology

• The sickling phenomenon results in increased mechanical fragility of the cell itself, increased blood viscosity, stasis, and lowered pH.
• Fragility
  
  • Haemolysis, Marrow hyperplasia, Osteopenia
• Viscosity
  
  • Vascular occlusion, Tissue anoxia, Osteonecrosis

Clinical Features

• Onset of symptoms and signs after 6 months of age, due to progressive decline in fetal hemoglobin levels.
• Weakness and pallor.
• Episodic abdominal crisis, jaundice, acute bone pain, dactylitis (painful sausage digit) due to intermittent sickle cell-induced infarctions.
• Predisposed to infections (esp salmonella)
• Compensatory hemopoiesis results in splenic enlargement followed by atrophy later in the disease process.
• Cardiomegaly with heart failure.
• Gallstones in 65% due to hyperbilirubinemia from hemolysis.
• Renal failure.
• Death (usually <30 yrs) due to infection, visceral infarction, or cardiac decompensation.

Radiographic Features

• Marrow Hyperplasia
  
  • Extent of hyperplasia determines the degree of osseous change.
  • Generalized osteopenia: sparse and course trabecular pattern
  • Large vascular channels
  • Widened medullary cavity
  • Cortical thinning
  • Loss of diaphyseal constriction in the small tubular bones
  • Marrow response much less than seen in Thalassemia – a reliable radiographic differential feature.
• Generalised Osteopenia
  
  • Loss of bone density of the spine is one of the important skeletal changes in sickle-cell anemia.
  • Very few other conditions cause radiolucency of the spine in young adults (e.g. Cushing’s syndrome and steroid therapy).
• Widened diploic space: space between inner and outer tables of skull
• “Hair-on-end” trabecular pattern – severe case
• Infarction
  
  • Disturbed bone growth
  • Epiphyseal necrosis (humeral and femoral heads)
  • Cortical infarcts:
    
    • Linear diaphyseal periostitis
    • Cortical splitting (bone within bone)
  • Organized metaphyseal medullary infarcts
  • Patchy areas of lucency and sclerosis
  • Soft tissue swelling
• Osteopmyelitis
  
  • Peculiar affinity exists for developing Salmonella osteomyelitis.
  • 100 times more likely than the normal population.
  • Portal of entry and pathophysiology unknown.
  • Hypothesis is that infarction in the intestine predisposes to entry into the circulatory system, with localization into other infarcted areas such as bone.
  • Uniquely bilateral and symmetrical
  • Diaphyseal location in long bones
  • Permeative and moth-eaten destruction
  • Prominent involucrum formation
  • Most commonly femur, tibia, fibula, humerus, radius, ulna. Spinal involvement may occur.

Question 6

Thalassemia

Answer 6

A hemolytic anemia characterized by microcytic, hypochromic, and shortlived red blood cells caused by deficient synthesis of hemoglobin polypeptide chains.

All types are transmitted by autosomal recessive genes and people of Mediterranean origin are more often affected than others.

Pathophysiology

• Major: homozygous, minor: heterozygous
• An imbalance in globin chain production (alpha, beta), which leads to ineffective hemopoiesis, hemolysis, and anemia.
• Bone changes a reflection of overgrowth and overactivity of marrow tissue
• Worse in children due to increased red marrow, bone changes regress with increased age as fatty marrow predominates

Clinical Features

• Thalassemia major, minor and intermedia forms
• Thalassemia major demonstrates the most severe clinical findings.
  
  • Survival beyond the first few years of life is unusual in the major form.
• Repeated blood transfusions result in hemochromatosis, cardiac failure and death by the second and third decade.
• Pallor, lethargy, retarded growth, hepatosplenomegally, mongoloid facies, maxillary overgrowth (rodent facies), inhibited sexual development.

Radiographic Features

• Coarsened trabecular pattern (honeycomb)
• Cortical thinning
• Osteoporosis
• Vascular channel enlargement
• Widened medullary cavity
• Erlenmeyer flask deformity: long bone constriction of diaphysis and flaring of metaphysis
• Premature fusion of growth plate resulting in shortening and deformity
• Long bone growth arrest lines
• Hair-on-end appearance (skull)
• Cardiomegaly

Question 7

Haemophillia

Answer 7

• A group of disorders characterized by deficiencies of various blood clotting factors, usually factor VIII (classic hemophilia A) or factor IX (Christmas disease, hemophilia B).
• Genetic; females carriers, disease manifests in males
• Lack of factors predispose to bleeding, within visceral organs, joints and within and around bones.
• Mild forms: may not demonstrate a significant bleeding tendency
• Severe forms: spontaneous bleeding or bleeding as a result of minor injuries
• Intraosseous haemorrhage: destructive and expansile alteration, esp femur, ilium
• Articular haemorrhage: acute and chronic haemarthroses – precipitates permanent joint change (haemophilic arthropathy) esp knee, ankle and elbow

Radiographic Features

Soft tissue swelling

• Due to hemarthrosis.
• Manifest as distension of the skin line, displacement of overlying fascial plane lines, and an increased soft tissue density due to hemosiderin deposits.

Osteoporosis

• Initially due to hyperemia. Especially evident in the epiphysis.
• With progressive disease, inactivity causes a more generalized decrease in bone density.

Subchondral Cysts

• Beneath the articular cortex well-demarcated, localized regions of radiolucency represent either escaped synovial fluid or localized hemorrhage.
• The articular cortex may be poorly defined.

Expansive, geographic bone lesions (pseudotumours)

• Results from hemorrhage within bone simulating a neoplasm.
• Rare complications (1-2%)
• Most commonly the femur, pelvis, tibia and hand.
• May also occur in soft tissues.

Epiphyseal Deformities

• Chronic hyperemia of the epiphyseal cartilage can produce accelerated growth and maturation of epiphysis in the growing skeleton.
• Epiphysis appear ballooned and enlarged in relation to the diaphysis.

Joint Disorganisation

• In long standing disease
• Complete loss of joint space
• Considerable articular fragmentation
• Sclerosis
• Osteophytes
• Bony misalignment
• May resemble neurotrophic arthropathy

Other

• Ischemic necrosis of the talus and femoral heads.
• Predisposition of fractures because of prominent osteoporosis.
• Ossification within gluteal or hamstring attachments.
• Chondrocalcinosis.
• Susceptibility to joint infection.

Question 8

Leukemia

Answer 8

• Myeloproliferative disease
• Malignant disease of the bone marrow and blood characterized by proliferating white blood cells.
• Radiographic signs evident in both childhood and adult leukemia

Childhood leukemia

• Most commonly presents under age 14
• Acute leukemia is the most common malignant disease of children 2-5yrs old.
• The most common form is acute lymphocytic leukemia
• Generalized joint pain, weakness, lethargy, lymphadenopathy, splenomegally, pallor and general malaise are usually evident on presentation.
• On investigation, ESR is elevated and peripheral blood smear shows excessively high or low WBC count and immature cell forms.
• Definitive diagnosis obtained by bone marrow analysis.

Radiographic Features

• Generalised Osteoporosis
• Radiolucent submetaphyseal cysts
  
  • A linear radiolucent region in the metaphysis beneath or parallel to the opaque zone of provisional calcification at the growth plate
  • DDx. Neuroblastoma, scurvy, syphillis
• Bone Destruction
  
  • Small, well defined medullary lesions that may produce endosteal destruction. (similar to multiple myeloma in the skull)
• Periosteal reaction
  
  • A single or multilayered laminated pattern involving long bone metaphysis and diaphysis.

Adult Leukemia

• Most commonly chronic and is of the myeloid or lymphatic variety; more common in older age
• Chronic lymphatic leukemia exhibits the most frequent osseous abnormalities.
• Acute adult leukemia will not show skeletal lesions since death usually occurs before development.
• Clinically: generalised weakness, fatigue, loss of weight, splenomegaly, lymphadnopathy, anaemia

Radiographic features are decreased inadults due to the reduction in red bone marrow. Findings are the same as for children.

Question 9

Scurvy

Answer 9

• Hypovitaminosis C
• Rare: infants 8-14mths fed on pasteurised milk; elderly with poor diet
• 4 months before symptomatology
• Capillary fragility: spontaneous haemorrhage
• Cutaneous petechiae, bleeding gums, melena, hematuria
• Joint swelling, pain, irritability
• Patients lie supine, motionless with thighs abducted

Radiographic Features

• Growing ends of long bones lower extremities
• Osteopenia
• Dense zone of provisional calcification
  
  • White line of Frankel
  • Enhancement of dense metahyseal zone of calcified cartilage
• Ring epiphysis (Wimbergers sign)
  
  • Dense peripheral margin of epiphysis
• Corner sign: irregularity of metaphyseal margin
• Pelkens spurs: at metaphyseal margins
• Scorbutic (Trummerfeld) zone
  
  • Radiolucent zone under white line of Frankel
• Subperiosteal haemorrhage
  
  • Blood lifts periosteum away, may eventually calcify

Question 10

Heavy Metal Posioining

Answer 10

Question 11

Fluorosis

Answer 11

Question 12

Hypervitiminosis

Answer 12

Question 13

Acromegaly

Answer 13

Pituitary eosinophilic adenoma = secretes excessive growth hormone

Clinical Features

• Prominent forehead
• Prognathic jaw
• Large hands & feet
• Thickened tongue
• Thickened heel pad
• Bilateral carpal tunnel
• Predisposed to DJD

Radiographic Features

• Hands, feet
  
  • Widened shafts
  • Bony protuberances
  • Enlarged distal tufts (spade-like)
  • Widened joint spaces
• Spine
  
  • Platyspondyly
  • Widening disc and facet joint spaces
  • Early DJD with exuberant osteophytosis

Question 14

Cushings Syndrome

Answer 14

Excessive glucocorticoids released from adrenal cortex

• Long-term use of corticosteroids for anti-inflammatory or immunesuppressive actions
  
  • Compression fractures spine
  • Avascular necrosis
  • Osteopenia
  • Delayed development
  • Infection
  • Destructive arthropathy
  • Impaired healing

3 types:

• Primary – caused by adrenal cortical malfunction
• Secondary – caused by anterior pituitary neoplasm
• Iatrogenic – caused by corticosteroid abuse
  
  • Tendon rupture
  • Soft tissue atrophy