Arthritis

Osteoarthritis

This is a condition where there is progressive degeneration of the articular cartilage.

It is a non-inflammatory arthritis which occurs due to “wear and tear” of the joint.

It usually affects the hips, knees, and the distal interphalangeal joints of the hand.

Risk factors include age, obesity, occupation (e.g., strenuous job) and trauma.

Symptoms

Non-inflammatory joint pain (stiffness < 30 minutes), affecting individual joints in a non-symmetrical pattern

Joint pain that worsens during the day

Joint clicking (crepitus), instability

May have joint effusion or antalgic gait

Bony enlargements in fingers, called Heberden’s nodes (DIP joints) and Bouchard’s nodes (PIP joints)

Key tests

Blood tests can be taken to rule out inflammatory (rheumatoid) arthritis

X-ray shows joint space narrowing, osteophyte formation, subarticular sclerosis, subchondral cysts

Management

Conservative – exercise to improve muscle strength, weight loss, stopping alcohol

Medical – analgesia, e.g., paracetamol and NSAIDs (e.g., ibuprofen)

Surgical – if symptoms are severe or persistent, joint replacement is considered

Septic Arthritis

This refers to an inflammatory arthritis which is caused by an infectious agent.

The pathogen is usually bacterial. Staphylococcus aureus is the most common organism, although N. gonorrhoeae is common in young sexually active adults.

It typically involves one joint and if left untreated can destroy a joint within 24 hours.

Organisms enter the joint from a skin lesion or via haematogenous spread.

Risk factors include joint surgery, immunosuppression, diabetes, prosthetic joint, intravenous drug use and pre-existing joint disease

Symptoms

Warm swollen joint

Acute stiffness and pain

Septic signs – fever, sweats, anorexia, tachycardia

Key tests

Blood tests show raised inflammatory markers (CRP, WCC)

Blood cultures – taken to see if patient has a bacteremia

Joint aspiration – should be sent for microscopy and culture

Management

Mainstay of treatment is IV antibiotics

May require surgical drainage of joint and washout

If the patient has a prosthetic joint, they should be discussed with orthopaedics urgently for consideration of surgery

Rheumatoid Arthritis

This is an autoimmune chronic, systemic inflammatory disease which is characterised by a symmetrical, deforming polyarthropathy.

It typically occurs in women of childbearing age and is associated with HLA-DR4.

The synovial membrane gets inflamed (synovitis). Granulation tissue forms at the edges of the synovial lining, leading to destruction of the cartilage and joint fusion.

Symptoms usually start in the small joints of both hands and feet before spreading to the larger joints.

Symptoms

Joint pain with morning stiffness (> 30 minutes) that improves with activity

Classic hand signs – pain in proximal interphalangeal joints, ulnar deviation of fingers, swan-neck and Boutonni.re deformity

Inflammatory symptoms – weight loss, low grade fever, lethargy

Extra-articular symptoms – anemia of chronic disease, pulmonary fibrosis

Key tests

Blood tests show raised inflammatory markers (CRP and ESR)

Serology – rheumatoid factor (IgM against Fc of IgG) is positive in about 70% of patients, but anti-CCP antibodies are more specific and sensitive for rheumatoid arthritis. However, a negative RF and anti-CCP does not rule out rheumatoid arthritis.

Newer tests assess for presence of anti-citrullinated protein antibodies ACPA

X-ray – joint space narrowing, loss of cartilage, osteopenia and soft tissue swelling

Management

For acute flares, steroids can be used

Symptomatic management with NSAIDs with PPI for gastric protection

Medical management involves disease modifying anti-rheumatic drugs (cDMARD) e.g., methotrexate, leflunomide, or sulfasalazine. Hydroxychloroquine can be used

If persistent, biological therapy can be considered e.g., infliximab

If significant joint deformity or nerve compression, surgery can be considered

Seronegative Spondyloarthropathies

This is a group of disorders (rheumatoid variants) which are characterised by an inflammatory arthritis but with negative serology for rheumatoid factor (seronegative).

They are associated with the haplotype HLA-B27. As well as affecting the peripheral joints, they may also involve the axial skeleton (spine and sacroiliac joints).

Ankylosing spondylitis

This is an inflammatory arthritis which typically affects the spine and sacro-iliac joints.

It is usually seen in young males, with gradual onset of low back pain and early morning stiffness (> 30 minutes).

If left untreated, it leads to vertebral fusion (bamboo spine), neck hyperextension (question-mark posture) and sacroiliitis.

It can also affect the eyes causing uveitis, and is associated with complications such as aortic regurgitation and achilles tendonitis.

It affects the spine bilaterally causing syndesmophytes and vertebral body fusion.

Management

Conservative measures – Exercise for back ache, physiotherapy

Medical – NSAIDs and immunosuppressant

Enteric arthropathy

This is an inflammatory arthritis associated with IBD and coeliac disease.

It also affects the spine and sacro-iliac joints and appears radiologically similar to ankylosing spondylitis.

It typically improves with management of the bowel symptoms.

Management

Improves with management of bowel symptoms + DMARDs

Psoriatic arthritis

This is an inflammatory arthritis which causes inflammation around the joints which have many tendon insertions, such as the spine, wrists, elbows and knees.

It classically affects the DIP joints of the hands and feet.

Patients may also get psoriasis rash as well as nail changes (pitting and onycholysis)

If left untreated can cause deformity of the fingers.

X-ray shows “sausage” fingers and erosive changes (pencil in cup deformity).

Management

NSAIDs and immunosuppressants 

Reactive arthritis

A condition when arthritis occurs as an autoimmune reaction to infection elsewhere.

It is usually seen in young males and associated with a recent infection (chlamydia).

Gives a classic triad of arthritis, urethritis and conjunctivitis.

It can also cause lesions on the foreskin and papules on the skin of the palms and soles (keratoderma blennorhagicum).

Patients have raised inflammatory markers with evidence of previous infection.

Key tests

Raised ESR and CRP + evidence of infection

Management

NSAIDs for inflammation + DMARD + antibiotics for infection 

Gout

This is a condition which is caused by the deposition of monosodium urate crystals (MSU) in the joints, which leads to an inflammatory arthritis.

Most cases involve the metatarsophalangeal joint of big toe, but other joints can also be affected, including the ankle, foot, hand and knee.

Consumption of alcohol or meat can precipitate arthritis.

Causes

Most commonly due to an unknown etiology of hyperuricemia

Leukhaemia – increased cell turnover gives hyperuricemia

Renal failure, loop/thiazide diuretics – leads to decreased excretion of uric acid

Lesch-Nyhan syndrome – X linked deficiency of enzyme HGPRT which also gives mental retardation

Symptoms

Monoarticular inflammatory arthritis attacks usually in the big toe (pain, swelling, redness)

If untreated can lead to development of tophi, which are aggregates of uric acid with fibrosis of joint

Key tests

Blood tests – raised serum uric acid level (may be normal during an acute attack) and inflammatory markers

Joint aspiration can be performed – polarised light microscopy of synovial fluid shows negatively birefringent uric acid crystals (needle shaped)

Ultrasound is recommend if joint aspiration cannot be done or diagnosis unclear

X-ray shows normal joint space, soft tissue swelling and periarticular erosion

Management

For acute attack, NSAIDs, colchicine or steroids

For prophylaxis, allopurinol or febuxostat

CPPD/Pseudogout

This is similar to gout, but crystals are made of calcium pyrophosphate dehydrate (CPPD)

Symptoms

Acute attacks of inflammatory arthritis in the joints.  Affects larger joints rather than big toe

Key tests

Light microscopy of synovial fluid – positively birefringent uric acid crystals (rhomboid shaped)

X-ray -Normal joint space, soft tissue swelling + periarticular erosions + Calcium deposition