Osteoporosis, Osteomyelitis & Osteoarthritis Flashcards
What is Osteoporosis?
Osteoporosis is a loss of bone density making the bones brittle, weaker and easy to fracture.
What is the most common demographic for OP?
Post menopausal women - typically over 50
Why is OP classified as a silent condition?
As there are no SSx until complicated by a fracture
What is the pathophysiology of OP?
Bone remodelling fluctuates throughout adult life and begins to decrease in mass after age 30. However if an external stimulus alters this natural decrease in mass further, we then start to see large loss of bone density in the body.
What are the types and their subtypes of OP?
- Primary (Post-menopausal & senile)
2. Secondary (Iatrogenic & Due to an illness)
What are some environmental risk factors for OP?
- Smoking
- Lack of vitamin D
- Dietary factors (calcium deficient)
- Hormone deficiency
- Lack of weight bearing exercise
What are common medical disorders that increase the risk of OP?
- Eating disorders
- Coeliac disease
- Endocrine disorders (cushings, diabetes mellitus etc)
- Chronic organ failure
- Overuse of bone loss causing drugs (corticosteroids, heparin etc)
What is the gold standard for screening OP?
DEXA - Dual energy Xray absorptiometry
-Often medicare rebated for older patients with GP referral
What medications are prescribed for OP?
- Biphosphonates
- Selective oestrogen receptor modulators (SERMs)
- HRT - comes with risk of CVD, stoke and breast cancer in women over 60
What other advise is recommended for OP patients?
- Increase vitamin D and calcium intake
- Decrease alcohol and smoking
- Weight bearing and falls prevention exercise
What is Osteomyelitis?
It is a red flag condition of an infection that effects the bone which can lead to progressive inflammatory destruction
What is the most common demographic to get osteomyelitis?
Children less than 2 or between 8-12
How is OM infection spread and classified?
- Through bacteria usually staphylococcus aureus (80%)
1. Hematogenous spread: Blood bourne bacterial spread common in children and immunocompromised
2. Spread from a contiguous source: usually due to trauma or post-surgical intervention
3. Secondary osteomyelitis - usually due to a vascular insufficiency/neuropathy such as diabetes
What are the 5 pathological phases of OM?
ISNFR
- Acute inflammatory phase - increase lymphocytes
- Suppuration - pus formation which increases pressure
- Necrosis - due to impacted blood supply
- Formation of new bone - 10 to 14 days
- Resolution from antibiotic therapy and pressure drainage
How does OM present in children?
- Symptoms prior to radiograph evidence
- Muted or covert symptoms
- Malaise, pain, fatigue
- History of trauma
- Pseudoparalysis
How does OM present in adults?
- Usually immunocompromised or elderly
- Bone tenderness
- Limp or decreased limb function
- Muscle spasm or other soft tissue involvement (usual initial symptom)
- Pyrexia and malaise
What is the best way to diagnose OM?
- MRI - 90% accuracy in early stage (expense high)
- Biopsy is also needed to determine antibiotic
How is OM treated?
- Antibiotics (long term via IV)
- Drainage
- Surgery - in chronic cases where debridement and amputation
Where does OM most commonly effect?
- Long bones
- Vertebra (Lx most common)
- SIJ
- Radius
What is osteoarthritis?
A type of arthritis which affects the whole joint – bone, cartilage, ligaments and muscles which results in a progressive loss of articular cartilage and remodeling of the underlying bone.
What is the pathophysiology of OA?
As it is primarily a disease of articular cartilage which contains chondrocytes. Genetic or environmental causes create proliferation of inflammatory mediators –> this breaks down type 2 collagen and proteoglycans and causes matrix remodelling and degradation –> finishing with cracking and erosion of the cartilage
What is the normal function of articular cartilage and it’s components?
Decreases friction of joints by resisting tension (type 2 collagen) and resisting heavy compression (proteoglycans) which is contained in the extra-cellular matrix
How does OA present in the clinic?
- Typically a women over 40 (But effects everyone)
- Usually gradual and slow onset
- Weightbearing joints
- Pain (relieved by rest, worst at EOD and in cold weather and stiffness in the morning that eases with movement)
- Bony enlargement
- Crepitus
- Restricted ROM
- Tenderness on palpation
How is OA diagnosed?
- Combination of clinical history and presenting SSx
- Xray can be utilised to show severity - need to consider if it will change initial management
What will a typical x-ray show in an OA patient?
- Loss of joint space
- Osteophytic growth
- Subchondral bone cyst and sclerosis
- Asymmetrical distribution
- Intra-articular loose bodies
- Articular deformity
- Vaccuum phenomenon (spinal)
How can you manage OA?
- Education and reassurance
- Medication - slow release paracetamol
- Correct modifiable risk factors (weight loss, injury, overuse)
- Exercise
- Manual therapy for biomechanical compensations
- Joint replacement
Where is Trabeculae bone found and what is its role?
- Spongy porous bone usually found at the epiphysis and metaphysis
- Trabecular bone transfers mechanical loads from the articular surface to the cortical bone. The hydraulic properties absorb shock
Where is Cortical bone found and what is its role?
- Mainly found in the diaphysis
- It is imperative to body structure and weight bearing because of its high resistance to bending and torsion
What hormones are Osteoclasts stimulated by?
PTH, Vit D, TH, Interleukin 1
What hormones are Osteoclasts inhibited by?
oestrogen, androgens, progesterone, calcitonin
How does the rate of bone loss differ in men vs women?
Men: after peak bone mass men loose less than 1% per year
Women: Less than 1% per year until menopause where they then can Bone loss can increase to around 2.5% per year (From around age 70 bone loss slow again)
What is the difference between primary and secondary OA?
Primary -no obvious triggering factor (most people fall under this)
Secondary –trauma, connective tissue disorders
