Non-Neoplastic Bone Pathology Flashcards
Name some metabolic bone diseases
- Osteoporosis
- Osteomalacia
- Hyperparathyroidism
- Paget’s
- Renal osteodystrophy
Describe the aetiology, features, symptoms, risk factors, x-ray findings, histological findings and biochemistry findings of osteoporosis
Aetiology
- Age related and post menopausal
- Reduced calcium intake
- Systemic drugs use
Disease features
- Reduced bone mass
- DEXA T score of >2. SD below normal
- Score of 1-2. below normal is osteopaenia
Symptoms
- Low impact fractures
- Usually NOF, Colle’s fractures
- Back pain
Risk factors
- Increased age
- Female
- Low BMI
- Smoking and poor diet
X-ray
- Usually none (unless fractured)
Histology
- Loss of cancellous bone
Biochemistry
- Calcium, phosphate and ALP all normal
Describe the aetiology, features, symptoms, risk factors, x-ray findings, histological findings and biochemistry findings of osteomalacia
Aetiology
- Vitamin deficiency from diet or malabsorption
Disease features
- Reduced bone mineralisation
Symptoms
- Adults: tenderness, muscle weakness
- Children: bone pain, bowing tibia, frontal bossing, pigeon chest
Risk factors
- Poor diet
- Malabsorption
X-ray
- Looser’s zones in NOF (pseudofractures)
Histology
- Excess unmineralised bone
Biochemistry
- Low calcium and phosphate
- Raised ALP
Describe the aetiology, features, symptoms, risk factors, x-ray findings, histological findings and biochemistry findings of hyperparathyroidism
Aetiology
- Excess PTH leads to excess Ca reabsorption
Disease features
- Osteotitis fibrosa cystica
Symptoms
- Moans, stones, bones, groans
- Renal stones
- Bone pain, fractures
Risk factors
- CKD
- Low vitamin D
X-ray
- Brown’s tumours
- Salt and pepper skull
Histology
- Osteotitis fibrosa cystica
Biochemistry
- High calcium
- Low/normal phosphate
- Low/normal ALP
Describe the aetiology, features, symptoms, risk factors, x-ray findings, histological findings and biochemistry findings of Paget’s disease
Aetiology
- A disorder of bone turnover
- 3 phases (osteolytic, osteolytic-osteosclerotic, quiescent-osteosclerotic)
Disease features
- Lytic and sclerotic lesions
- Affects skull, vertebrae and pelvis most commonly
Symptoms
- Bone pain
- Microfactures
- Nerve compression
- Deafness
Risk factors
- Over 0 year
- Caucasian
X-ray
- Cotton wool spots
- Lytic lesions
- Sclerotic lesions
Histology
- Huge osteoclasts with many nuclei
- Mosaic pattern of lamellar bone
Biochemistry
- Normal calcium and phosphate
- very high ALP
Describe the aetiology, features, symptoms, risk factors, x-ray findings, histological findings and biochemistry findings of renal osteodystrophy
Aetiology
- Associated with CKD
Causes Osteotitis fibrosis cystica, osteomalacia, osteosclerosis, growth retardation, osteoporosis
All features will depend on the site and form of bone disease
Describe the epidemiology, aetiology, joints, features, crystal type, investigations and management of gout
Usually affects middle aged men, and is caused by a high purine level. It commonly affects the MTP joint of the great toe and presents with a hot, swollen intensely painful joint.
The crystals are urate, needle-shaped, and are negatively birefringent.
Manage acute attacks with colchicine, being sure not to drop the purine level too quickly. Manage chronic gout with allopurinol.
Describe the epidemiology, aetiology, joints, features, crystal type, investigations and management of pseudogout
Usually affects the elderly and is commonly unknown in its cause. It usually affects the knee or shoulder and presents with a hot, swollen joint with an effusion.
The crystals are calcium pyrophosphate, are rhomboidal and are positively birefringent.
Treatment is with NSAIDs or intra-articular steroids.
Describe the different types of fracture
Simple
- Just a fracture across the bone
Compound
- Fracture and displaced bone
Greenstick
- Common in children
Comminuted
- Compound plus multiple smaller fractures
Impacted
- Fracture with the bones impacted into each other
What is the process of bone reformation
1) Organisation of a haematoma aka a pro-callus
2) Formation of fibrocartilaginous callus
3) Mineralisation of fibrocartilaginous callus
4) Remodelling of bone along weight bearing lines
What can impact the healing of a fracture
- Type
- Neoplasm
- Metabolic disorder
- Drugs
- Vitamin deficiency
- Infection
Describe osteomyelitis
It can be spread by haematogenous spread, local extension or trauma with many of the cases being bacterial.
Adults: S. aureus and most commonly effects the vertebrae, the jaw and the toes.
Children: haemophilus influenzae, or group B strep, commonly affecting the long bones
It presents with pain, swelling, tenderness with general features of malaise, fever, chills and leucocytosis.
On x-ray changes are usually not found until 7-10 days post infection and shows lytic destruction of the bone.
Describe rarer causes of osteomyelitis
TB:
- Shows Pott’s disease of the spine
- Langhans type giant cells
- Immunocompromised patients
Syphilis:
- Congenital or acquired
Describe osteoarthritis
A degenerative joint disease mainly affecting vertebrae hips and knees.
May see Heberden’s nodes (DIPJ) and Bouchard’s nodes (PIPJ).
Describe lyme disease
This is a inflammatory arthropathy caused by a tick bite of the Ixodes dammini species carrying the Borrelia burgdorferi bacteria.
It presents with erythema chronicum migrans, a rash 7-10 days after the bite, and symptoms of the musculoskeletal system, the heart and arthritis.
It can be treated with a antibiotics, or protected against by vaccines.
