Bone and Joints Flashcards
Paget’s disease of bone (osteitis deformans)
Increased bone turnover associated with increased osteoblasts and osteoclasts with resultant remodelling, bone enlargement, deformity and weakness
Presentation of Paget’s disease of bone
Asymptomatic in ~70%
Deep, boring pain and bony deformity and enlargement (typically pelvics, lumbar spine, skull, femur and “sabre tibia”)
Complications of Paget’s disease of bone
Pathological fractures OA Hypercalcaemia Nerve compression due to bony overgrowth Osteosarcoma
Mx of Paget’s disease of bone
Analgesia
Alendronate may reduce pain and deformity
Ix for Paget’s disease of bone
Radiology: localised enlargement of bone, patchy cortical thickening with sclerosis, osteolysis and deformity
Blood chemistry: normal Ca2+ and PO4, raised ALP
Osteomalacia
Normal amount of bone but mineral content low (excess uncalcified osteoid and cartilage)
Called rickets if it occurs while bone is growing, osteomalacia if it occurs post-epiphyseal fusion
Presentation of osteomalacia
Bone pain and tenderness
Fractures (esp femoral neck)
Proximal myopathy due to low phosphate and vit D deficiency
Causes of osteomalacia
Vit D deficiency or resistance (inherited) Renal osteodystrophy Liver disease Drug-induced (e.g. anticonvulsants) Tumour-induced
Mx of osteomalacia
In dietary insufficiency, give vit D
In malabsorption or hepatic disease, give vit D2
If due to renal disease or vit D resistance, give alfacalcidol or calcitriol
Monitor Ca2+ initially weekly, and if any N+V
Ix in osteomalacia
Mildly decreased Ca2+, PO4 Increased ALP, PTH Decreased vit D (except if resistance) Bone biopsy: incomplete mineralisation XR: loss of cortical bone, apparent partial fractures without displacement may be seen
Cause of gout
Deposition of monosodium urate crystals in and near joints
Can be precipitated by trauma, surgery, starvation, infection, diuretics
Associated with raised plasma urate
Complications of gout
Urate deposits (tophi) Renal disease (stones, interstitial nephritis)
Ix in gout
Polarised light microscopy of synovial fluid: negative birefrigent urate crystals
Serum urate frequently raised but can be normal
XR: only soft tissue swelling in early stages, lateral there may be well-defined “punched-out” erosions in juxta-articular bone but no sclerotic reaction
Mx of acute gout
High-dose NSAID or coxib (Sx should subside in 3-5/24)
If CI, use colchicine (NB In renal impairment, NSAID and colchicine are CI)
Steroids (oral, IM, intra-articular) may be used
RICE
Prevention of gout attacks
Weight loss Avoid prolonged fasts, alcohol excess, purine-rich meats, low dose aspirin (which increases serum urate) For prophylaxis (if >1 attack in 12 months, tophi or renal stones), use allopurinol
SEs of allopurinol
Fever
Rash
Decreased WCC
Calcium pyrophosphate deposition
Umbrella term used to describe different patterns of disease including:
Acute CPP crystal arthritis (pseudogout): usually spontaneous and self-limiting
Chronic CPPD: inflammatoryy RA-like (symmetrical) polyarthritis and synovitis
OA with CPPD
Ix for pseudogout
Polarized light microscopy shows positive birefrigent crystals
XR: soft tissue Ca2+ deposition
Mx of pseudogout
RICE
Intra-articular steroids
NSAIDs +/- colchicine
Ankylosing spondylitis
Chronic inflammatory condition of the spin and sacroiliac joints of unknown aetiology
Seronegative spondyloarthropathies
Ankylosing spondylitis
Enteric arthropathy
Psoriatic arthritis
Reactive arthritis
Shared features of spondyloarthropathies
1) Seronegativity (RhF -ive)
2) HLA B27 association
3) “Axial arthritis”: pathology in spine and sacroiliac joints
4) Asymmetrical large-joint oligoarthritis or monoarthritis
5) Enthesitis: inflammation of site of insertion of tendon or ligament into bone, e.g. plantar fasciitis, Achilles tendonitis, costochondritis
6) Dactylitis: inflammation of entire digit (“sausage digit”) due to soft tissue oedema, and tenosynovial and joint inflammation
7) Extra-articular manifestations: iritis (anterior uveitis), psoriaform rashes, oral ulcers, aortic valve incompetence, IBD
Ix for ankylosing spondylitis
Clinical Dx
MRI is most sensitive, better for early disease
XR: sacroiliitis - look for irregularities/erosions/sclerosis affecting lower half of sacroiliac joints (esp iliac side), vertebral syndesmophytes are characteristic (fuse with vertebral body above causing ankylosis)
Raised ESR/CRP
Normocytic anaemia
HLA B27 +ive
Mx of ankylosing spondylitis
Exercise, not rest, for backache
NSAIDs
TNF-a blockers
Local steroid injections
Surgery: hip replacement, rarely spinal osteotomy
Increased risk of fractures (consider bisphosphonates)
Enteric arthropathy
Associated with IBD, GI bypass, coeliac and Whipple’s disease
Often improves with treatment of GI Sx
DMARDs for resistant cases
Psoriatic arthritis
10-40% of those with psoriasis
Can occur before skin changes
Ix for psoriatic arthritis
XR: erosive changes, with “pencil-in-cup” deformity in severe cases
Mx of psoriatic arthritis
NSAIDs Sulfasalazine Methotrexate Ciclosporin Anti-TNF agents
Reactive arthritis
Sterile arthritis typically affecting the lower limb ~1-4/52 after urethritis or dysentry; may be chronic or relapsing
Reiter’s syndrome
Urethritis
Arthritis
Conjunctivitis
Ix for reactive arthritis
Increased ESR, CRP
XR: enthesitis with periosteal reaction
Mx of reactive arthritis
No specific cure
Splint affected joints acutely, give NSAIDs or intra-articular steroids
Consider sulfasalazine or methotrexate if Sx >6/12
NB Treating original infection may make little difference to arthritis
Common sites for AVN
Head of femur
Neck of talus
Scaphoid
Osteosarcoma
Aggressive primary cancer of bone that produces malignant osteoid (more frequently originates in metaphyseal region of long bones)
Most prevalent in children and adolescents
Presentation of osteosarcoma
Pain that may be worse at night, intermittent and of varying intensity
May present with fracture (malignant bone is weaker)
Mx of osteosarcoma
Complete radical surgical en bloc resection of cancer
Neoadjuvent chemotherapy
Osteochondroma
Most common benign tumour of bone
Cartilage-capped bony projections or outgrowth on the surface of bones (exostoses)
Can occur anywhere cartilage forms bone (most commonly long bones, pelvis, scapula)
Mostly asymptomatic
Mx of osteochondroma
Excision is curative (minimal risk of malignant transformation if not excised)
