Metabolic, Endocrine and Nutritional Flashcards
What is OSTEOPENIA?
A decrease in bone mineral density (BMD) below normal reference values due to an underlying disruption in the microarchitecture of bone and osteopenia
Occurs secondary to uncoupling of osteoclast-osteoblast activity, resulting in a quantitative decrease in bone mass
- Early third decade of life = Peak bone mass achieved for MALES and FEMALES
- >30yoa = bone resorption due to dynamic bone remodelling, continuing into later decades of life.
Diagnosed via dual-energy x-ray absorptiometry (DXA) bone scans
T-score between -1 to -2.5
What is Osteoporosis?
A skeletal disorder characterised by reduced bone mass and disruption of architecture resulting in increased bone fragility and increased fracture risk
- 1 in 2 women >50yoa
- 1 in 5 men over >50yoa
Vertebral fractures – HALLMARK
- m/c mid thoracic area and TL junction (T8-L1) and L4
What is the epidemiology of osteoporosis?
- M/C > 50yoa (Females 4x > than Males BUT Males more likely to demonstrate secondary causes of decreased bone mass
- Females >65yoa
- Males >70yoa
- people with previously fractured or injured bone after the age of 50
- people who have rheumatoid arthritis
- 30% of all postmenopausal women (TYPE 1 – POSTMENUPAUSAL OSTEOPOROSIS)
- 70% of those aged 80yoa (TYPE2 – AGE-ASSOCIATED OSTEOPOROSIS)
What are the classifications of osteoporosis?
- Primary Causes:
- natural bone loss occurring gradually during adulthood
- Family history
- Females with naturally smaller bones (specifically Caucasian and Asian women) - Secondary Causes:
- Lifestyle factors e.g.
- alcohol use
- smoking
- sedentary lifestyle
- thin body habitus (BMI under 18.5)
- Certain medications
- Medical conditions e.g.
- Hyperthyroidism and Hyperparathyroidism
- Anorexia
- Malabsorption syndromes
- Chronic renal failure
What are the radiological findings of osteoporosis?
- Increased radiolucency
- Cortical thinning
- Pencil thin cortex with smooth inner surface – SEVERE CASES
- Resorption of cortical bone at possible three sites (endosteal, periosteal and intracortical)
- m/c at endosteal surface – endosteal scalloping - Altered trabecular pattern
- Coarsely trabeculated / striated appearance
- Fractures and deformities – MC VERTEBRAL FRACTURES
- Ghost vertebral appearance – due to loss of trabecular density and thinned out linear shadow
- Vertebral Fractures:
- Defined by: reduction in anterior, middle or posterior VB height
- Described as: wedge-shaped (anterior height reduced in relation to posterior height)
- Thoracic region: Posterior height > anterior height by 1 – 3mm (even in normal individuals)
THEREFORE
- Loss of height >4mm = TRUE VERTEBRAL FRACTURE - Traumatic Compression Fracture vs Anterior Wedging of Osteoporosis:
- USEFEL DISTINGUISH: Normal bone density, angular or steplike cortical defects and normal amount of callus formation
- OSTEOPOROSIS: beak in cortex or significant callus formation – RARE
- TRAUMATIC FRACTURES: rarely restricted to endplate alone BUT a key frequent feature in Osteoporosis - Femoral Fractures:
- Classified as :
- Cervical (Femoral neck or Intracapsular)
- Trochanteric (Extracapsular) Fractures
- m/c in elderly individuals with a greater degree of generalised osteoporosis
- Subchondral insufficiency
- Curvilinear subchondral lucency OR sclerosis in the superior or superolateral aspects of the femoral head - Stress fractures of Sacrum and Pubis – Common in osteoporosis
- Identified by:
- localised periosteal response
- transverse opaque zones of callus formation
What is treatment/management for osteoporosis?
Medications
- Hormone Replacement Therapy
- AKA postmenopausal hormone therapy - Healthy Lifestyle Changes
- A balanced diet with plenty of vitamin D
- Increasing calcium and vitamin D intake
- Exercising regularly with weight-bearing exercises (lifting weights, hiking, jogging, climbing stairs)
- Stopping smoking
- Limiting alcohol and caffeine intake
What is the difference between osteopenia and osteoporosis?
A decrease in bone mineral density (BMD) below normal reference values, yet not low enough to meet the diagnostic criteria for osteoporosis
A t-score between:
- -1.0 or higher = Normal
- -1 to -2.5 = Osteopenia
- <-2.5 = Osteoporosis
Decreasing BMD values are reflective of an underlying disruption in the microarchitecture of bone and osteopenia, and osteoporosis is considered quantitative, not qualitative, disorders of bone mineralization
Osteoporosis more severe form of osteopenia
What is Hyperparathyroidism?
Excess parathyroid hormone (PTH) in the body
Common cause of hypercalcaemia
Primary, secondary or tertiary
- PRIMARY:
- Parathyroid adenoma
- Parathyroid hyperplasia
- parathyroid carcinoma - SECONDARY:
- chronic hypocalcaemia - TERTIARY:
- chronic overstimulation of hyperplastic glands in renal insufficiency
What is the Epidemiology of Hyperparathyroidism?
- Females more common (74%)
- Most common in 7th decade
What are signs and symptoms of Hyperparathyroidism?
- Mostly asymptomatic or mild symptoms
- Weakness
- Fatigue
- Polyuria
- Polydipsia
- Hypotonic, weak muscles
- Renal calculus formation
- Possible bone tenderness
What are the radiological findings of Hyperparathyroidism?
- Subperiosteal bone resorption
- Affects radial aspect of proximal and middle phalanges of 2nd and 3rd Fingers
- Medial aspect of tibia, femur and humerus - Subchondral resorption
- Lateral end of clavicles
- Symphysis pubis
- Sacroiliac joints - Subligamentous resorption
- Ischial tuberosity
- Trochanters
- Inferior surface of calcaneus and clavicle - Decreased bone density
- Accentuated trabecular pattern
- Loss of cortical definition
What are the spinal radiological findings of Hyperparathyroidism?
- Osteoporosis with trabecular accentuation
- Endplate concavities
- Uniform subchondral sclerosis
- Rugger Jersey Spine
What is scurvy?
AKA Barlow’s disease or Hypovitaminosis C
Vitamin C deficiency – Increased vascular fragility
Decreased osteoblastic activity and cartilage proliferation = decreased formation of bony matrix
What are the signs and symptoms of scurvy?
- Swelling of joints
- Irritability
- Pain
- Lying motionless, supine, “Frog legged’
What are the radiological finding of scurvy?
- Osteopenia
- Dense ZPC
- White line of Frankel - Ring Epiphyses
- Wimberger sign - Corner sign
- Pelken’s spurs
- Scorbutic Zone
- Trummerfeld zone - Subperiosteal hemorrhages
