Rheumatology Flashcards
What is a joint?
- A joint is the part of the body where two or more bones meet to allow movement.
- The greater the range of movement, the higher the risk of injury because the strength of the joint is reduced.
- The six types of freely movable joint include ball and socket, saddle, hinge, condyloid, pivot and gliding.
What is a ligament?
- A ligament is a fibrous connective tissue which attaches bone to bone, and usually serves to hold structures together and keep them stable.
What is a tendon?
- A tendon is a fibrous connective tissue which attaches muscle to bone.
- Tendons may also attach muscles to structures such as the eyeball.
Describe the basic anatomy of a joint?
Bone –> ligament –> fibrous capsule –> synovial membrane –> synovial joint –> articular cartilage –> articulating bone
What is the purpose of the articular cartilage?
- Reduces friction
- Shock absorption
What is the purpose of the synovial membrane?
- Highly vascularised
- Secretes & absorbs SF
What is the purpose of the synovial fluid?
- Lubrication
- Shock absorption
- Nutrient distribution - hyaline cartilage is avascular and relies on diffusion from SF
What are the main inflammatory markers?
1) ESR (erythrocyte sedimentation rate)
• Rises with inflammation/infection
• Increased fibrinogen makes RBCs “stick together” and therefore fall faster
• Therefore, if ESR rises, the rate of fall is faster
• ESR rises and falls slowly (days to weeks)
• False positives (falsely high)
- Females, age, obesity and SE Asians have higher ESR
• Raised in SLE
2) CRP (C-reactive protein)
- Acute phase protein
- Released in inflammation/infection
- Produced by liver in response to IL-6 (pro-inflammatory cytokine)
• Rises and falls rapidly
o High at 6 hours and peaks at 48 hours
o If patient has infection in 24 hours, ESR won’t have risen yet but CRP will have
3) Auto-antibodies
• Immunoglobulins that bind to self-antigens
What are the inflammatory markers in rheumatoid arthiritis?
- Rheumatoid Factor (RF)
* Anti - Cyclic Citrullinated Peptide (CCP)
What are the inflammatory markers in SLE (systemic lupus erythematosus)?
- Anti-nuclear Antibody (ANA) – binds to antigen within cell nucleus
- Double stranded DNA (dsDNA)
What is osteoarthiritis?
- Non-inflammatory degenerative/(wear and tear) of joints resulting from loss of articular cartilage
- Osteoarthritis is an age-related (degenerative), dynamic reaction pattern of a joint in response to insult or injury
- All tissues of the joint are involved
- Articular cartilage is the most affected – produced by chondrocytes
- Changes in underlying bone at the joint margins
Describe the epidemiology of osteoarthritis?
- Most common type of arthritis
- Especially in elderly and females
- Most common condition affecting synovial joints
- Most important condition relating to disability as a result of locomotor symptoms
- 8.75 million people in the UK seek treatment for OA
What are the risk factors of osteoarthritis?
- Think wear and tear
• Age (uncommon below 50)
o Cumulative effect of traumatic insult
o Decline in neuromuscular function
• Female – prevalence increases after menopause
• Occupation
o Manual labour associated with OA of small joints of hands
o Farming associated with OA of hips
o Football associated with OA of knees
• Genetics
o Most relevant in polyarticular disease
o OA hip less common in Afro-Caribbean and Asian populations
o OA hand rare in black African and Malaysian population.
• Obesity
o Linear relationships between BMI and risk of hip and knee OA
o Not thought to be due to mechanical factors
o Also, association with OA of non-weight bearing joints e.g. hand joints
o Obesity is a low-grade inflammatory state
o Release of: (inflammatory cytokines)
- IL-1
- TNF
- Adipokines (leptin, adiponectin)
- Previous joint trauma
- Rheumatoid Arthritis
- Gout
• Other factors o Local trauma o Inflammatory arthritis – e.g. Rheumatoid Arthritis o Abnormal biomechanics e.g. - Joint hypermobility - Congenital hip dysplasia - Neuropathic conditions
• Osteoporosis reduces risk of OA
Describe the pathology of osteoarthritis?
• Imbalance in process of cartilage breakdown by wear and production by chondrocytes in favour of cartilage breakdown (chondrocyte ECM breakdown)
-Complex process but two main parts:
1) Hyaline cartilage degradation
2) Abnormal chondrocyte homeostasis
- Chondrocytes lose ability to generate and repair cartilage
- Chondrocytes overexpress proteases and cytokines
- Leads to cartilage
breakdown and inflammation - The exposure of the underlying subchondral bone results in sclerosis (narrowing)
- Joint space lost over time
- Some genetic predisposition as well
- Not many leukocytes in synovial fluid
What is the typical presentation of osteoarthritis?
- Elderly with knee/hip pain
- Age related.
- Weight bearing joints
- Improves with rest and worse with activity
- Pain on movement of joint – crepitus.
- Bony swellings – DIP (Heberden’s nodes) and PIP (Bouchard’s nodes)
- XRAY – Osteophytes, joint space narrowing, subchondral cysts and subarticular sclerosis.
What are the symptoms of osteoarthritis?
- Variety of patterns but always SYNOVIAL JOINTS.
- Weight-bearing joints are most involved
- Hips, knee, cervical, lumbar spine
-Whole joint affected
Cartilage, subchondral bone, ligaments, menisci, synovium, capsule
• Joint pain on movement
o Hip – groin pain
o Pain at rest in severe OA
o Pain at end of day
• Crepitus – crunching sensation when moving joint
• Functional impairment
o Walking
o Activities of daily living
What are the signs of osteoarthritis?
- Morning stiffness <30 minutes
- Worse at end of day
- Pain increases with use
- Asymmetrical joint involvement
• Joints most commonly affected
o Mostly affects knee/hip/vertebra i.e. big weight-bearing joints
o Affects DIP and PIP joint
o First carpometacarpal joints – base of thumb
• Joint swelling – osteophytes grow outwards
o Bony enlargement o Effusion o Synovitis (if inflammatory component) o Bony swellings (not inflamed) - Heberden’s nodes – DIPJ - Bouchard’s nodes – PIPJ
• Other joint abnormalities o Limited range of movement o Crepitus– abnormal popping or crackling sound o Tenderness o Deformities
What is the differential diagnosis for osteoarthritis?
- Rheumatoid Arthritis
- Gout
- Psoriatic arthritis
What are the investigations for osteoarthritis?
• X-ray o LOSS - Loss of joint space (narrows) - Osteophytes - Subchondral sclerosis (narrowing) - Subchondral cysts
• Bloods – normal
o CRP may be slightly elevated
o Rheumatoid Factor and Anti-nuclear antibodies NEGATIVE
- MRI
- Aspiration of synovial fluid
What is the management of osteoarthritis?
• Conservative o Patient education o Activity and exercise o Weight loss o Physiotherapy o Occupational therapy o Footwear o Orthoses
o Walking aids
- Stick – can unload a hip by up to 60%
- Frame
o Hot/cold packs • Medical – analgesic ladder o Topical - NSAIDs - Capsaicin
o Oral - Paracetamol (first line) - NSAIDs (second line) • Consider PPI for any long term NSAIDs - Opioids - dihydrocodeine
o Transdermal patches
- Buprenorphine
- Lignocaine
o Intra-articular steroid injections – hyaluronic acid
- Role remains unclear
o DMARDs have a role in inflammatory OA
• Surgical
o Osteophyte removal
o Joint replacement/fusion – if very severe
o Arthroscopy
- Only for loose bodies
- Indications
- Uncontrolled pain (particularly at night)
- Significant limitation
o Osteotomy
o Arthroplasty
What is rheumatoid arthritis?
-RA is a chronic systemic autoimmune inflammatory disease due to deposition of immune complexes in synovial joints which causes symmetrical, deforming polyarthritis
What are the risk factors for rheumatoid arthritis?
- Genetic disposition-HLA-DR4
- Gender
- Smoking
- Family history
- Infection
- Females more than men; 30-50 years
• Common – 0.5-1% of population
Describe the pathophysiology of rheumatoid arthritis?
- Complex autoimmune attack against synovium of joint –> synovitis (INFLAMMATION OF THE SYNOVIAL LINING OF JOINTS tendon sheaths or bursae)
- Synovium thickens and grows out over the surface of cartilage (Pannus)
- Pannus destroys the articular cartilage and subchondral bone –> bone erosion
- Antibodies are key players which cause the inflammation and keep it going
What are the articular features of rheumatoid arthritis?
- Symmetrical pain and swelling of affected joints (also at rest) - worse in morning + cold
- Metacarpophalangeal (MCP) joints, Proximal interphalangeal (PIP) joints, wrist joints, Knee joints
- Rarely affected: distal interphalangeal (DIP) joints, first carpometacarpal (CMC) joint, and the axial skeleton (except for the cervical spine)
- Morning stiffness (often > 30 min) that usually improves with activity
- Joint deformities:
- Swan neck deformity
- Boutonniere deformity:
- Hitchhiker thumb deformity (Z deformity of the thumb)
- Ulnar deviation of fingers
- Piano key sign: dorsal subluxation of the ulna
- Hammer toe or claw toe
- Painful handshake is an early sign of arthritis
- Carpal tunnel syndrome
