This is a chronic inflammatory disease of the spine and sacroiliac joints. There is predominance in young males and the condition is associated with HLA B27 (positive in 95%).
Causes
The exact cause and pathophysiology of this condition are not known. However, it is thought to be associated with HLA B27.
Signs and symptoms
•
Question mark posture.•
Bamboo spine: due to calcification of ligaments.•
Pain and stiffness: symptoms improve with exercise.Investigations
•
Bloods: seronegative for rheumatoid factor.•
Radiology: CXR and MRI scan assess changes in the spine.Treatment
•
Conservative: patient education. Refer to physiotherapy.•
Medical: analgesia (NSAIDs) and DMARDs, e.g. sulphasalzine (first line).•
Surgery: corrective spinal surgery.Complications
•
Osteoprosis.•
Spinal fractures.•
Increased risk of cardiovascular disease, e.g. stroke and myocardial infarction.MAP 10.3 Spondyloarthropathies (Continued )
161
Musculoskeletal System
Map 10.3 Spondyloarthropathies PSORIATIC ARTHRITISWhat is psoriatic arthritis?
This is an inflammatory arthritis that is associated with the skin condition psoriasis. It is associated with HLA B27. The signs and symptoms also depend on how and where the joints are affected. Accordingly, psoriatic arthritis may be split into 5 subtypes:
1 Asymmetrical oligoarthritis (distal and proximal interphalangeal joints). 2 Symmetrical rheumatoid-like arthropathy.
3 Ankylosing spondylitis variant. 4 Polyarteritis with skin and nail changes. 5 Arthritis mutilans.
Causes
The exact cause is unknown. It is thought to be due to an inflammatory process coupled with genetic involvement of the HLA B27 gene. The greatest risk factor is a family history of psoriasis.
Signs and symptoms
•
Psoriasis: well-demarcated salmon-pink plaques with evidence of scaling. These plaques are usually present on the extensor surfaces (chronic plaque psoriasis) but sometimes smaller plaques may occur in a raindrop pattern over the torso. This is called guttate psoriasis and is often preceded by an upper respiratory tract infection/sore throat that is caused by Streptococcus.•
Joint pain and stiffness.•
Swelling of affected joints.•
Nail changes: there are 4 nail changes noted in psoriasis: yellowing of the nail, onycholysis, pitting and subungual hyperkeratosis.Investigations
•
Psoriasis is a clinical diagnosis.•
Bloods: seronegative for rheumatoid factor.•
Radiology: ‘Pencil-in-cup’ deformity on hand X-ray. X-ray of affected joints to assess severity.Treatment
•
Conservative: patient education. Refer to physiotherapy. Explain to patients that psoriasis does not have a cure and control of the disease is more realistic.•
Medical: analgesia (nonsteroidal anti-inflammatory drugs [NSAIDs]) and disease modifying antirheumatic drugs (DMARDs), e.g. methotrexate (first line). Manage psoriasis.•
Surgery: rarely joint replacement.Complications
•
Neurological manifestations if atlanto–axial joint involvement.•
Joint destruction.ENTEROPATHIC ARTHROPATHIES
What are enteropathic arthropathies?
This is an arthritis that develops in association with inflammatory bowel disease (IBD). It is indistinguishable from reactive arthritis.
Causes
The exact cause and pathophysiology of this condition are not known. However, it is thought to be associated with HLA B27.
Signs and symptoms
•
Those of IBD, see page 40.•
Spondylitis.•
Sacroiliitis.•
Peripheral arthritis: usually of large joints.Investigations
•
Those for IBD, see page 40.•
Radiology: X-ray of affected joint. Assess severity.Treatment
•
Analgesia (NSAIDs).•
Treatment of IBD, see page 40.Complications
•
Severely decreased mobility with axial involvement.ANKYLOSING SPONDYLITIS What is ankylosing spondylitis?
This is a chronic inflammatory disease of the spine and sacroiliac joints. There is predominance in young males and the condition is associated with HLA B27 (positive in 95%).
Causes
The exact cause and pathophysiology of this condition are not known. However, it is thought to be associated with HLA B27.
Signs and symptoms
•
Question mark posture.•
Bamboo spine: due to calcification of ligaments.•
Pain and stiffness: symptoms improve with exercise.Investigations
•
Bloods: seronegative for rheumatoid factor.•
Radiology: CXR and MRI scan assess changes in the spine.Treatment
•
Conservative: patient education. Refer to physiotherapy.•
Medical: analgesia (NSAIDs) and DMARDs, e.g. sulphasalzine (first line).•
Surgery: corrective spinal surgery.Complications
•
Osteoprosis.•
Spinal fractures.•
Increased risk of cardiovascular disease, e.g. stroke and myocardial infarction.MAP 10.3 Spondyloarthropathies (Continued )
Chapter_10.indd 161
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162 Map 10.4 Gout
What is gout?
Gout is an inflammatory crystal monoarthropathy caused by the deposition of urate crystals. These monosodium urate crystals often
precipitate in the metatarsophalangeal joint (MTPJ). Gout involving the big toe is known as a podagra.
Causes
There are many causes of gout but essentially anything that increases urate levels may be the underlying cause. Some examples include,
HorrificDELAY:
•
Hyperuricaemia, Hereditary.•
Diuretics (thiazides).•
Ethanol.•
Leukaemia.•
renAl impairment.•
associated with Lesch–NYhan syndrome.Signs and symptoms
•
Calor, dolor, rubor and tumour (heat, pain, redness and swelling) of the affected joint, which is usually the MTPJ in 50% of patients.•
Tophi (urate deposits) may be present on tendon surfaces, e.g. the elbow, or visible on the ear.•
Patients may have symptoms of renal calculi.Investigations
•
Bloods: serum urate levels, FBC, WCC, U&Es, creatinine, ESR, CRP.•
GFR: assess kidney function.•
Synovial fluid analysis: positive if birefringent monosodium urate crystals seen.Characteristic Pseudogout Gout
Joints affected Larger proximal Classically 1st MTPJ Crystal type Calcium
pyrophosphate crystals
Sodium urate crystals
Crystal shape Rhomboid Needle Light microscopy Negative
birefringence
Strongly positive birefringence
Pseudogout vs. gout Complications
•
Joint damage.•
Renal calculi.•
Tophi formation.Treatment
•
Conservative: patient education. Lifestyle advice, e.g. encourage alcohol reduction and a low purine diet. Review medications that the patient is taking and stop causative agents, e.g. thiazide diuretics, if possible.•
Medical:○ Analgesia.
○ Acute: colchicine and steroids.
○ Chronic: allopurinol. Febuxostat may be used if allopurinol is not tolerated by the patient.
MAP 10.4 Gout
163
Musculoskeletal System
Map 10.4 Gout What is gout?Gout is an inflammatory crystal monoarthropathy caused by the deposition of urate crystals. These monosodium urate crystals often
precipitate in the metatarsophalangeal joint (MTPJ). Gout involving the big toe is known as a podagra.
Causes
There are many causes of gout but essentially anything that increases urate levels may be the underlying cause. Some examples include,
HorrificDELAY:
•
Hyperuricaemia, Hereditary.•
Diuretics (thiazides).•
Ethanol.•
Leukaemia.•
renAl impairment.•
associated with Lesch–NYhan syndrome.Signs and symptoms
•
Calor, dolor, rubor and tumour (heat, pain, redness and swelling) of the affected joint, which is usually the MTPJ in 50% of patients.•
Tophi (urate deposits) may be present on tendon surfaces, e.g. the elbow, or visible on the ear.•
Patients may have symptoms of renal calculi.Investigations
•
Bloods: serum urate levels, FBC, WCC, U&Es, creatinine, ESR, CRP.•
GFR: assess kidney function.•
Synovial fluid analysis: positive if birefringent monosodium urate crystals seen.Characteristic Pseudogout Gout
Joints affected Larger proximal Classically 1st MTPJ Crystal type Calcium
pyrophosphate crystals
Sodium urate crystals
Crystal shape Rhomboid Needle Light microscopy Negative
birefringence
Strongly positive birefringence
Pseudogout vs. gout Complications
•
Joint damage.•
Renal calculi.•
Tophi formation.Treatment
•
Conservative: patient education. Lifestyle advice, e.g. encourage alcohol reduction and a low purine diet. Review medications that the patient is taking and stop causative agents, e.g. thiazide diuretics, if possible.•
Medical:○ Analgesia.
○ Acute: colchicine and steroids.
○ Chronic: allopurinol. Febuxostat may be used if allopurinol is not tolerated by the patient.
MAP 10.4 Gout
Chapter_10.indd 163
Musculoskeletal System
164
Osteoma
•
Location: skull.•
Associated with Gardner’s syndrome (this syndrome is associated with the APC gene on chromosome 5).Giant cell tumour
•
Location: epiphysis (long bones).•
Soap bubble appearance.Ewing’s sarcoma
•
Location: diaphysis (long bones), pelvis, scapula, ribs.•
Onion skin appearance.•
Very aggressive.•
Predominance in children.Osteoblastoma
•
Location: vertebrae.•
Similar to osteoid osteoma.Benign Malignant
Enchondroma
•
Location: intramedullary bone.•
Cartilaginous neoplasm.•
Seen in phalanges.Osteochondroma
•
Location: metaphysis (long bones).•
Most common benign bone lesion.Chondrosarcoma
•
Location: medullary cavity of femur, humerus, tibia, pelvis, scapula, spine, skull and craniofacial area.Osteoid osteoma
•
Location: femur and tibia, phalanges and vertebrae.•
Intracortical lesion best differentiated on CT.•
Nidus.Osteosarcoma