Important locomotor presentations

Question 1

Rheumatoid arthritis (RA): overview

Answer 1

RA is a chronic inflammatory multisystem autoimmune disease mediated by pro-inflammatory cytokines such as TNF-alpha and may associate with antibodies such as rheumatoid factor and anti-CCP.
30-40% of patients with rheumatoid arthritis are not positive for rheumatoid factor.
10-20% of patients do not develop anti-CCP antibodies.
Usually the onset of symptoms in RA is over a few days to a few weeks, and the progression is slow.
Additional joints are involved over weeks and months.
It can rarely have an acute onset (over a day or 2).
The course can be episodic with complete resolution between attacks (palindromic).
The clinical features of RA can be divided into articular and extra-articular.

Question 2

Rheumatoid arthritis (RA): demographics

Answer 2

Affects around 1-3% of the population.
Occurs in all races.
Peak age of onset 40s-50s.
Female:male ratio ~3:1.

Question 3

Rheumatoid arthritis (RA): articular features

Answer 3

RA usually presents as a symmetrical polyarthritis affecting the wrists and small joints of the hands and feet.
Occasionally, a patient presents with a mono- or oligoarthritis of larger joints such as the knees, wrists, shoulders, or elbows.
Common symptoms are joint pain, stiffness, and swelling which are typically worse in the morning and improve as the day progresses.

Question 4

Rheumatoid arthritis (RA): articular features, signs

Answer 4

Synovitis involving the wrists (dorsal swelling), metacarpophalangeal (filling in of gaps between the MCP heads) and proximal interphalangeal joints (lateral expansion of IPJs), with sparing of the distal interphalangeal and 1st carpometacarpal joints.
With modern and aggressive treatment of synovitis, joint destruction and resulting deformities are not common in patients developing RA in the last decade.

Question 5

Rheumatoid arthritis (RA): articular features, inspection

Answer 5

Symmetric swelling of proximal interphalangeal joints (PIPs).
Symmetric swelling of metacarpophalangeal joints (MCPs).
Ask the patient to make a fist- subtle swelling of MCP joints is seen as filling of the ‘valleys’ between metacarpal heads.
Ulnar deviation at MCP joints.
Thin skin with scars (long term corticosteroid use).
Wasting of intrinsic muscles.
Tuck sign: tubular swelling due to extensor tenosynovitis, seen on the dorsal aspect of wrist and on finger extension.
Swan-neck deformity: hyperextension of PIPJ and flexion of DIPJ.
Boutonnière deformity: flexion at PIPJ, extension at DIPJ.
Volar subluxation at MCP and wrist joints.
Rheumatoid nodules on extensor tendons, joints, sites of mechanical irritation (elbow, toe, and heel).

Question 6

Rheumatoid arthritis (RA): articular features, palpation

Answer 6

Warmth and tenderness at DIP, PIP, MCP and wrist joints (if active).
Doughy feeling of synovial proliferation at joints.
Piano key sign: up and down movement of the ulnar styloid in response to pressure from examiners’ fingers.

Question 7

Rheumatoid arthritis (RA): common extra-articular features

Answer 7

Rheumatoid nodules: common at sites of pressure (elbows and wrists), associated with more severe disease and rheumatoid factor positivity.
Sjögren’s syndrome (keratoconjunctivitis sicca).
Raynaud’s phenomenon.
Interstitial lung disease (pulmonary fibrosis, pulmonary nodules).
Pleurisy/pleural effusions.
Episcleritis/scleritis.

Question 8

Rheumatoid arthritis (RA): uncommon extra-articular features

Answer 8

Neurological features: mononeuritis multiplex, peripheral neuropathy.
Cardiac features: pericarditis/pericardial effusions.
Systemic features: fever, malaise, weight loss, lymphadenopathy.

Question 9

Rheumatoid arthritis (RA): rare extra-articular features

Answer 9

Vasculitis: nail fold infarcts, cutaneous ulceration, digital gangrene.
Skin lesions: pyoderma gangrenosum.
Lung features: Caplan’s syndrome (massive lung fibrosis in RA patients with pneumoconiosis), obliterative bronchiolitis, Felty’s syndrome (RA, splenomegaly, and neutropenia).
Amyloidosis (proteinuria, hepatosplenomegaly).

Question 10

Rheumatoid arthritis (RA): complications

Answer 10

Anaemia.
Cataracts (chloroquine, steroids).
Peripheral nerve entrapment (e.g. carpal tunnel syndrome).
Cervical myelopathy (atlanto-axial subluxation).
Palmar erythema, skin thinning, and muscle wasting (synovitis in nearby joints).
Non-Hodgkin’s lymphoma (systemic inflammation).
Ischaemic heart disease (systemic inflammation).
Osteoporosis.
Lower respiratory tract infections.

Question 11

Rheumatoid arthritis (RA): causes of anaemia in RA

Answer 11

Anaemia of chronic disease.
GI bleeding: NSAIDs or corticosteroid use.
Bone marrow suppression: disease-modifying anti-rheumatic drugs, e.g. methotrexate.
Megaloblastic anaemia: due to folic acid deficiency or pernicious anaemia.
Macrocytic anaemia: methotrexate, azathioprine.

Question 12

Osteoarthritis: overview

Answer 12

Osteoarthritis is a chronic disorder of synovial joints characterised by focal cartilage loss and an accompanying reparative bone response.
It represents the single most important cause of locomotor disability with a prevalence which increases with age, and has a female preponderance.

Question 13

Osteoarthritis: symptoms

Answer 13

Swelling
Deformity
Stiffness
Weakness
Pain, normally worse after activity and relieved by rest

Question 14

Osteoarthritis: inspection

Answer 14

Posterolateral swelling at the distal interphalangeal (DIP, Heberden’s nodes) and proximal interphalangeal (PIP, Bouchard’s nodes) with characteristic radial or ulnar deviation of the phalanx.
Squaring of thumb base, wasting of thenar eminence, observed on the volar aspect (1st carpometacarpal joint).

Question 15

Osteoarthritis: inspection, knee

Answer 15

Patient standing, examine from front.
Varus or valgus deformity?
Suprapatellar or infrapatellar effusion?
Quadriceps wasting?
Fixed flexion at knee with the patient lying supine?

Question 16

Osteoarthritis: palpation, hands

Answer 16

Cool bony swelling at IPJs.

Joint line tenderness at IPJ and 1st CMCJ.

Question 17

Osteoarthritis: secondary causes

Answer 17

Trauma (fracture, meniscal, or cruciate injury).
Inflammatory arthritis, e.g. RA.
Abnormalities in articular contour (hip and acetabular dysplasias) or alignment (varus or valgus knee malalignment).
Generalised or localised hypermobility (Ehlers-Danlos, Marfan’s, benign hypermobility syndrome).
Previous septic arthritis.
Avascular necrosis.

Question 18

Paget’s disease (osteitis deformans): overview

Answer 18

A disorder of bone remodelling characterised by increased osteoclast and osteoblast activity, leading to accelerated bone resorption and disorganised bone formation.
Paget’s disease is more common in males and affects ~1-2% of the Caucasian adults >55 years.
It occurs more commonly in the UK than anywhere else in the world.
The exact aetiology remains unknown, however a number of factors have been implicated, including a slow viral infection such as paramyxovirus.
The axial skeleton is preferentially affected, common sites of involvement include the pelvis, femur, lumbar spine, skull, and tibia in a descending order of frequency.

Question 19

Paget’s disease (osteitis deformans): common clinical features and complications

Answer 19

Pain: bone pain, not joint pain- pain is present day and night and is not made worse by joint movements.
Deformity: enlargement of the skull, exaggerated thoracic kyphosis, anterior bowing of the tibia, lateral bowing of the femur.
Fractures.
Hearing loss (ossicle involvement, or VIII nerve compression).

Question 20

Paget’s disease (osteitis deformans): less common clinical features and complications

Answer 20

Spinal stenosis.

Nerve compression syndromes.

Question 21

Paget’s disease (osteitis deformans): rare clinical features and complications

Answer 21

Hypercalcaemia during immobilisation.
Cardiac failure.
Sarcomatous change.
Hydrocephalus.
Cord compression.

Question 22

Crystal arthropathies: gout, overview

Answer 22

A disorder of purine metabolism.
Characterised by hyperuricaemia due to either overproduction or under excretion of uric acid.
Prolonged hyperuricaemia leads to the deposition of urate crystals in synovium, connective tissues, and the kidney.
These crystals are then shed, leading to acute gout.
Gout is associated with metabolic syndrome (central obesity, insulin resistance, hypertension, and ischaemic heart disease).
Most patients are middle aged or older with risk factors for gout such as renal failure, excess alcohol intake, and diuretic usage.

Question 23

Crystal arthropathies: gout, clinical features of acute gout

Answer 23

Sudden onset (hours) of severe pain and swelling classically in the great toe MTPJ, worse at night, and associated with redness.
Occasionally multiple joints are involved, e.g. knees, ankles ± systemic symptoms.
Some patients (frequently elderly and those on diuretics) present with large-joint (knee, ankle, shoulder, or wrist) involvement or with polyarticular gout.

Question 24

Crystal arthropathies: gout, clinical features of chronic tophaceous gout

Answer 24

Tophi (deposits of urate crystal) occur in:

• the digits (at IPJs, finger pulp); in the presence of osteoarthritis, gouty tophi preferentially occur at the IPJs affected by Heberden’s or Bouchard’s nodes,
• near the 1st metatarsophalangeal joint.
• in bursae (e.g. olecranon bursa).
• near the Achilles tendon.
• in tendon sheaths.
• on the helix (ear).

Question 25

Crystal arthropathies: calcium pyrophosphate deposition (CPPD), overview

Answer 25

CPPD may occur in the cartilage (chondrocalcinosis), joint capsule, and tendons. Established risk factors include increased age >60 years and osteoarthritis. If CPPD is present in those <55 years or is florid and polyarticular, the patient should be screened for haemochromatosis, hypophosphataemia, hypomagnesaemia, and hyperthyroidism. Knees, wrists, MCPJs, and hips are the most commonly involved joints.

Question 26

Crystal arthropathies: calcium pyrophosphate deposition (CPPD), presentation

Answer 26

Asymptomatic: chondrocalcinosis. Acute CPP crystal arthritis (pseudogout): the commonest cause of acute monoarthritis in the elderly. CPPD and OA: symptoms of OA with or without superimposed episodes of acute synovitis. Chronic CPP crystal inflammatory arthritis: uncommon.

Question 27

Causes of hyperuricaemia

Answer 27

More common in the summer months due to reduced fluid intake and increased fluid loss. Drugs: diuretics, ethanol, salicylates, pyrazinamide, ethambutol, nicotinic acid, and cyclosporin. Chronic renal failure. Myeloproliferative and lymphoproliferative disorders (increased purine metabolism). Obesity. Hypertension. Hypothyroidism. Hyperthyroidism. Familial. Excessive dietary purines.

Question 28

Crystal arthropathies: gout, causes of premature gout

Answer 28

Renal failure. Solid organ transplant with immunosuppression with calcineurin inhibitors. Haematological malignancy. Inherited errors of metabolism.

Question 29

Spondyloarthropathies: overview

Answer 29

These include ankylosing spondylitis, psoriatic arthritis, reactive arthritis and enteropathic arthritis. This is a group of related and overlapping forms of inflammatory arthritis which characteristically lack rheumatoid factor and are associated with HLA-B27. They present at any age, though young males are primarily affected.

Question 30

Spondyloarthropathies: clinical features

Answer 30

Enthesitis (inflammation of enthesis, the insertion of a tendon, ligament, or joint capsule onto a bone). Sacroiliitis. Dactylitis. Peripheral arthritis predominantly affecting the large joints.

Question 31

Spondyloarthropathies: ankylosing spondylitis, common symptoms

Answer 31

``` Back pain (may be localised to buttocks) and stiffness, typically worse in early hours 2-5am and on waking up in the morning. Pain recurs after long periods of rest and is relieved by activity. Patients report dramatic response to NSAIDs (first line tx). Chest pain may be present as a result of T-spine involvement as well as enthesitis at the costochondral joints. Pain, swelling, and stiffness may be present in peripheral joints affected by inflammatory arthritis, e.g. shoulder, hips, knees, ankles. ```

Question 32

Spondyloarthropathies: ankylosing spondylitis, musculoskeletal features/signs

Answer 32

``` 'Question mark' posture (loss of lumbar lordosis, fixed kyphosis of the T-spine, compensatory hyperextension of the C-spine. Protuberant abdomen. Schober's test positive. Sacroiliac joint tenderness. Achilles tendonitis. Plantar fasciitis. ```

Question 33

Spondyloarthropathies: ankylosing spondylitis, some extra-skeletal features

Answer 33

``` Anterior uveitis. Aortic regurgitation. Apical lung fibrosis. AV block. Amyloidosis. Weight loss. ```

Question 34

Spondyloarthropathies: psoriatic arthritis, overview

Answer 34

Psoriatic arthropathy affects up to 10% of patients with psoriasis and may precede or follow the skin disease. Does not correlate with severity of skin lesions. 5 main subtypes: asymmetrical distal interphalangeal joint arthropathy, asymmetrical large joint mono- or oligoarthropathy, spondyloarthropathy and sacroiliitis (usually asymmetric), rheumatoid-like hands (seronegative), arthritis mutilans.

Question 35

Spondyloarthropathies: psoriatic arthritis, associated clinical features

Answer 35

Psoriatic plaques (extensor surfaces, scalp, behind the ears, navel and natal clefts). Nail involvement (pitting, onycholysis, discolouration, and thickening). Dactylitis (sausage-shaped swelling of the digits due to tenosynovitis). Enthesitis.

Question 36

Spondyloarthropathies: reactive arthritis, overview

Answer 36

An aseptic arthritis, strongly linked to a recognised episode of infection. Common causes are gut and genitourinary pathogens. Mainly affects young adult males and usually presents with an asymmetric oligoarthritis. Symptoms start a few days to weeks after the infection. Enthesitis and dactylitis are other common features. Extra-articular features include urethritis, conjunctivitis, and skin lesions.

Question 37

Spondyloarthropathies: reactive arthritis, Reiter's syndrome

Answer 37

A form of reactive arthritis associated with the classic triad of arthritis, urethritis, conjunctivitis. It often follows dysenteric infections such as shigella, salmonella, campylobacter and yersinia or infections of the genital tract. Mouth ulceration, circinate balanitis, keratoderma blennorrhagica, plantar fasciitis.

Question 38

Spondyloarthropathies: enteropathic arthritis

Answer 38

Peripheral or axial arthritis, commonest extra-intestinal manifestation of IBD. Patients are usually young adults, no gender predisposition. Musculoskeletal manifestations: sacroilliitis (usually symmetric), peripheral arthritis, dactylitis, enthesopathy. Only 7% are HLA-B27 positive.

Question 39

Osteoporosis: overview

Answer 39

Systemic skeletal disorder involving reduced bone mass (osteopenia) and micro-architectural deterioration, resulting in an increased risk of fracture. Classification and treatment are based on measurement of bone mineral density (BMD), with comparison to that of a young, healthy adult. The underlying pathology is related to an imbalance between the osteoblasts producing bone and the osteoclasts removing bone which ultimately produces net bone loss. WHO definition: BMD <2.5 SD below mean of young adult BMD of same gender = osteoporosis.

Question 40

Osteoporosis: primary osteoporosis, overview

Answer 40

95% of osteoporosis in women, 70-80% osteoporosis in men. Seen in postmenopausal women and elderly men. No single underlying cause of osteoporosis.

Question 41

Osteoporosis: primary osteoporosis, risk factors

Answer 41

``` Older age >50 years. Female gender. Low dietary calcium and vitamin D intake. FHx of osteoporosis. Parental history of hip fracture. BMI <19. Delayed menarche. Premature menopause. Sedentary lifestyle. Excess caffeine intake. ```

Question 42

Osteoporosis: secondary osteoporosis

Answer 42

Has an identifiable underlying cause of osteoporosis. | Patients may have other identifiable risk factors as for primary osteoporosis.

Question 43

Osteoporosis: clinical features

Answer 43

The process leading to osteoporosis is asymptomatic. The condition is usually diagnosed after the patient has a fragility fracture (fracture caused by falling from a standing height or less)- common sites of osteoporotic fracture include femoral neck, wrist, and vertebrae. Vertebral fracture may be asymptomatic sometimes, being diagnosed only when the patient has a spinal radiograph for kyphosis, loss of height, or for unrelated reasons.

Question 44

Osteoporosis: secondary causes

Answer 44

Prolonged immobilisation/weightlessness. Malignancy. GI diseases: malabsorption syndrome, IBD, liver disease, anorexia nervosa. Rheumatologic diseases: RA, SLE, AS. COPD. Genetic disease: cystic fibrosis, Ehlers-Danlos syndrome. Endocrine diseases: T1DM, hyperparathyroid, hyperthyroid, hyperprolactinaemia, Cushing's syndrome, hypogonadism. Drugs: corticosteroids, phenytoin, long-term heparin. Alcohol >recommended daily allowance and smoking.