Disease Profiles: Bone and Joint Disorders Flashcards
List one way corticosteriods indirectly impact bone density
Inhibition of gonadal and adrenal steroid production
Which forms of malignancy are patients with Paget’s disease of bone at increased risk of?
Osteosarcoma, fibrosarcoma
The following organisms most commonly cause what type of prosthetic joint infection?
Coagulase-negative staph (e.g. Staph. epiderdimis), cutibacterium, corynebacterium, S. aureus
Chronic prosthetic joint infection (3 weeks + after operation)
How does vitamin D deficiency cause osteomalacia/rickets?
Vitamin D deficiency increases calcium absorption, osteoclastic activity, and release of Ca2+ from bone → impairs mineralisation of newly formed osteoid
What are Bouchard’s nodes?
Osteophytes of the PIP joints (can be seen in OA but more commonly seen in RA)
What is osteomyelitis?
Infection of the bone and/or bone marrow
The following organisms most commonly cause what type of
prosthetic joint infection?
Staph. aureus, coagulase-negative staph (e.g. Staph. epiderdimis)
Early prosthetic joint infection (within 2-3 weeks of operation)
Which patient group is most likely to develop primary osteoarthritis?
> 50 years, more common in females
How does chronic osteomyelitis develop?
From an untreated acute osteomyelitis
When would you prescribe an osteoporotic patient oral bisphonates?
Normal patients: T score = -2.5
If ongoing steroid requirement >/= 7.5mg prednisolone for 3 months or more or if there is a prevalent vertebral fracture, consider treatment with T score < -1.5
When would you refer a patient for a DEXA scan?
Anyone with a 10 year risk assessment for any OP fracture of at least 10%
Any patient over 50 years with a low trauma fracture
Which patient group is most likely to develop joint hypermobility syndrome?
Higher incidence in females, usually presents in childhood or 3rd decade
Why does acute osteomyelitis in children commonly localise to the metaphyses of long bones?
The metaphyses of children’s long bones contain abundant tortuous vessels with sluggish flow which can result in accumulation of bacteria
Which patient group is most likely to develop Paget’s disease of bone?
> 50
Describe the clinical presentation of hypocalcaemia
Paraesthesiae, muscle cramps, irritability, fatigue, seizures, brittle nails
The following organisms most commonly cause osteomyelitis in which patient group?
S. aureus, Enterobacter sp., and group A and B Strep
Newborns (<4 months)
What is the diagnostic investigation for osteomyelitis?
Bone biopsy
When should rifampicin be added to patients with a prosthetic joint infection?
If culture is positive for rifampicin-sensitive staphlococci
Define primary osteoarthritis
Osteoarthritis due to normal ‘wear and tear’ of joints as people age
Which type of fractures are common in patients with type II osteoporosis?
Femoral neck fractures and vertebral fractures
What is tertiary hyperparathyroidism?
Seen in patients with chronic secondary hyperparathyroidism (usually CKD) who develop an adenoma which will continue to produce PTH despite biochemical correction
Which patient groups would you assess with a 10-year osteoporotic fracture risk calculator?
Anyone over 50 years with risk factors
Anyone under 50 years with very strong clinical risk factors - early menopause, glucocorticoids
Which organism is associated with septic arthritis in the elderly, IV drug users and the seriously ill?
Escherichia coli
Define diffuse osteomyelitis
Segment of bone is infected resulting in skeletal instibility e.g. infected non-union
What is SAPHO and CRMO?
Conditions which cause chronic non-bacterial osteomyelitis, chest wall commonly affected
The following organisms commonly cause what type of prosthetic joint infection?
S. aureus, GNB
Haematogenous (chronic-late onset)
How can the risk of developing osteoporosis be reduced?
Building up peak bone mineral density by way of exercise, good diet and healthy levels of sunlight exposure before bone density starts to decline
What is secondary hyperparathyroidism?
Hyperparathyroidism due to physiological overproduction of PTH secondary to hypocalcaemia, usually caused by vitamin D deficiency or CKD
Why are post-menopausal women more likely to develop osteoporosis?
There is an increase in osteoclastic bone resorption with the loss of protective effects of oestrogen after menopause
Name two consequences of a vertebral neck fracture due to osteoporosis
Result in thoracic kyphosis → loss of height
Once patient has had one vertebral body fracture they are at increased risk of additional fractures
What is rickets?
Qualitative defect of bone IN CHILDREN with abnormal softening of the bone due to deficient mineralization of osteoid secondary to inadequate amounts of calcium and phosphorus
This affects the growing skeleton
Define joint hypermobility syndrome
Patient with hypermobile joint(s) develops chronic pain lasting 3 months or longer
What is osteoarthritis?
Chronic disease involving the imbalance between wear and repair of articular (hyaline) cartilage leading to progressive cartilage loss and accompanying periarticular change
How would you manage a patient with osteomalacia/rickets?
Vit D therapy with calcium and phosphate supplementation
The following organisms most commonly cause osteomyelitis in which patient group?
S. aureus, occasionally Enterobacter or Streptococcus sp
Adults
What is a sequestrum and what is its clinical significance in osteomyelitis?
A sequestrum is a dead fragment of bone that usually breaks off
Once a sequestrum is present antibiotics alone will not cure the infection
List some aspects of lifestyle advice with a patient with osteoporosis
Increase calcium intake - postmenopausal women aim 1000 mg calcium per day
Exercise - high intensity strength training and low-impact weight-bearing exercise
Avoidance of excess alcohol and smoking
Fall prevention
Where does chronic osteomyelitis tend to occur in adults?
Axial skeleton (spine or pelvis) with haematogenous spread from pulmonary or urinary infections, or from infection of the intervertebral disc
Describe the pharmacological management of osteoarthritis
Analgesia as needed (paracetamol, NSAIDs, avoid opiates)
Local intra-articular steroid injections for flare-up up to 3x year
Which organisms most commonly cause osteomyelitis in sickle cell anaemia patients?
S. aureus the most common, Salmonella species common and fairly unique to sickle cell patients
Describe the examination findings of a patient with septic arthritis
Reduced ROM +/- swelling
May have systemic fever
Describe the clinical presentation of spinal osteomyelitis
Insidious onset of back pain which is constant and unremitting
What is the quantitative definition of osteoporosis?
Bone density is 2.5 standard deviations below the mean peak value of young adults of the same race and sex
Describe the clinical presentation of acute osteomyelitis
Gradual onset pain at site of infection, point tenderness, swelling, redness, warmth
Systemic findings: malaise, fever, chills
When would HRT be indicated in osteoporosis?
Not indicated for osteoporosis except in early postmenopausal women who also have significant perimenopausal symptoms
When would you empirically treat a patient with septic arthritis?
If they are septic
Define localised osteomyelitis
OM affecting cortex and medullary bone
Which type of fractures are common in patients with type I osteoporosis?
Colles fractures and vertebral insufficiency fractures
What investigations would you perform in suspected prosthetic joint infection?
Culture of perioperative tissue
Bloods - CRP, blood culture
X-ray
How would you manage a patient with early or haematogenous prosthetic joint infection?
DAIR - debridement, antibiotics (12 weeks), implant retention
What is type I osteoporosis?
Exacerbated loss of bone in the post‐menopausal period
What is Brodie’s abscess?
Subacute osteomyelitis found in children with a more insidious onset; bone reacts by walling off the abscess with a thin rim of sclerotic bone
Why does osteoporosis increase fracture risk?
The reduced density and increased porosity increases the fragility of bone
Why does the formation of pus make osteomyelitis difficult to treat?
Impairs local blood flow
What blood test results would indicate osteomalacia/rickets?
↓ calcium and serum phosphate, ↑ serum ALP
How would you manage a normal patient with chronic prosthetic joint infection?
Stage 2 exchange - removal of joint and 6 weeks of aggressive antibiotic therapy, once infection under control perform a revision joint replacement
What is the average bone loss per year once peak bone mass has been reached?
0.7%
Define superficial osteomyelitis
OM affecting the outer surface of bone
What are brown tumours?
Osteoporotic bone prone to fracture
Associated haemorrage elicits macrophage reaction and processes of organisation and repair → mass of reactive tissue ‘brown tumour’
When would testosterone be indicated in osteoporosis?
Men with clinical and biochemical evidence of hypogonadism
Describe the clinical presentation of septic arthritis
Single warm, red, painful joint with pain whenever the joint moves
Describe the examination findings of a joint with osteoarthritis
Joint line tenderness, crepitus, deformity, stiff on testing ROM
What is an involucrum in osteomyelitis?
The formation of new bone around the area of necrosis
What is DEXA scanning?
Measure of bone mineral density - predicts fracture risk independently of other risk factors
What is the first line treatment for the majority of patients with osteoporosis?
Oral bisphosphonates e.g. alendronate, risedronate
Define secondary arthritis
Osteoarthritis that affects an unexpected site due to overuse, previous injury or previous arthritis
Describe the management of joint hypermobility syndrome
Patient eduction, physio, analgesia as required
When does peak bone mass occur?
Young adulthood
What is a prosthetic joint infection (PJI)?
Periprosthetic infection involving the joint prosthesis and adjacent tissue
How would you diagnose osteoarthritis?
Clinical diagnosis
What is type II osteoporosis?
Osteoporosis of old age with a greater decline in bone mineral density than expected
Define medullary osteomyelitis
OM affecting medullary bone
What causes contagious osteomyelitis?
Spread of infection from adjacent tissue e.g. injuries, infected foot ulcer or pressure sore, PJI etc.
What is Gaucher’s disease?
Lysosomal storage disorder which can mimic osteomyelitis
Describe the classical x-ray findings seen in osteoarthritis
Loss of joint space, marginal osteophytes, sclerosis (subchondral), subchondral cysts
What is the second most common cause of septic arthritis in adults?
Streptococci
What is sessile bacteria?
Phenotypic transformation of planktonic bacteria to form a biofilm encased in an extracellular matrix
Occurs in chronic deep infections
Antibiotics cannot penetrate the biofilm - removal of infected prosthesis needed
What does ‘squaring of the thumb’ indicate?
1st CMC joint OA
The following organisms most commonly cause osteomyelitis in which patient group?
S. aureus, group A Strep, H. influenzae, Enterobacter sp
Children (4 months to 4 years)
Describe the surgical management of osteoarthritis
Joint replacements
Arthroscopic sugary e.g. to remove loose bodies
When would you perform imaging in suspected osteoarthritis?
If there is doubt over diagnosis
Describe the clinical presentation of osteomalacia/rickets
Bone pain of the pelvis, spine and femora, deformities from soft bones (particularly in rickets), pathological fractures, S+S of hypocalcaemia
What is osteoporosis?
Quantitative defect of bone characterised by reduced bone mineral density and increased porosity
What empirical antibiotic would you give for an adult septic patient who has septic arthritis?
Flucloxacillin
Why must you always aspirate any hot, red and tender joint?
Septic until proven otherwise - emergency due to rapid irreversible cartilage damage
What x-ray results would indicate osteomalacia/rickets?
Pseudofractures (aka Looser’s zones), particularly of the pubic rami, proximal femora, ulna and ribs
Describe the clinical presentation of chronic osteomyelitis
Recurrent pain usually following a prior episode of osteomyelitis, swelling, redness
What are subchondral cysts?
Accumulation of synovial fluid in a joint with OA
Which investigations would you perform in suspected osteomyelitis?
Probe to bone test, blood CRP, imaging (x-ray then consider others e.g. MRI)
Gold standard - bone biopsy to confirm
How would you manage a patient with septic arthritis?
1-2 weeks IV antibiotics to cultured organism, may require joint washout, if good progress PO antibiotics til 6 weeks antibiotics completed
Where does osteomyelitis that has travelled from another site (haematogenous) commonly localise in children?
Long bone metaphysis
What investigations would you perform in suspected septic arthritis?
Aspiration of joint fluid
Bloods - CRP, blood culture if pyrexic
X-ray, consider MRI
How would you manage chronic osteomyelitis?
Can be suppressed with antibiotics but may be unsuccessful
Surgery - take bone cultures, remove sequestrum and debride infected/non-viable bone
IV antibiotics for several weeks after surgery
Acute osteomyelitis in the absence of recent surgery usually occurs in which age group?
Children
What is fibrosa cystica?
The result of unchecked hyperparathyroidism, which results in an overproduction of PTH
Continued osteoclasis → osteoporosis, brown tumours and osteitis
Describe the clinical presentation of Paget’s disease of bone
Can be asymptomatic
Pain - micro-fracture or nerve compression
Enlargement and abnormal shape of bone
Increased metabolism can cause warm skin, AV shunt
What are the 3 stages of Paget’s disease of bone
- Osteolytic
- Mixed osteoclasis and osteoblastic activity
- Osteosclerotic
When would teriparatide be indicated in a patient with osteoporosis?
Recommended over oral bisphosphate in postmenopausal women with at least 2 moderate or 1 severe low trauma vertebral fracture to prevent vertebral fracture
What is sickle cell osteomyelitis?
OM that occurs during a sickle cell crisis
What are Heberden’s nodes?
Osteophytes of the DIP joints (only seen in OA)
Describe the clinical presentation of joint hypermobility syndrome
Joint pains especially after exercise/physical work, frequent sprains and dislocations, thin stretchy skin
How would you manage acute osteomyelitis?
‘Best guess’ antibiotics IV unless there is an abscess which requires drainage
If infection fails to resolve - second line antibiotics, surgery to take a sample for culture and remove infected bone/tissue
What causes localised osteoporosis?
Osteoporosis which develops through disuse of particular bones
What is the most common mechanism of spread for a septic arthritis?
Haematogenous
What is eburnation?
The surface of a joint with OA becomes ‘polished’ - subchondral sclerosis
Define localised osteoarthritis
Osteoarthritis affecting a single joint e.g. hips, knees, finger interphalangeal joints, facet joints of lower cervical and lower lumbar spines
The following organisms most commonly cause osteomyelitis in which patient group?
S. aureus (80%), group A Strep, H. influenzae, and Enterobacter sp.
Children/adolescents (4 years to adult)
When would calcium and/or vitamin D supplements be indicated in a patient with osteoporosis?
If dietary intake is poor/limited sunlight exposure
What are the most common causative organisms for prosthetic joint infection?
Staph. aureus and staph. epiderdimis
Where does osteomyelitis that has travelled from another site (haematogenous) commonly localise in adults?
Vertebrae
Define severe osteoporosis
Bone density is 2.5 standard deviations below the mean peak value of young adults of the same race and sex WITH a fragility fracture
What is hyperparathyroidism?
Involves overactivity of the parathyroid glands with high levels of parathyroid hormone (PTH)
How would you manage a frail patient with chronic prosthetic joint infection?
Stage 1 exchange - removal of joint and antibiotics
SERMS (selective estrogen receptor modulators) are rarely used in the management of osteoporosis, they only reduce the risk of which type of fractures?
Vertebral
Describe the effect of Paget’s disease on the bone structure
Thick excess bone with abnormal reversal lines (mosaic pattern)
Bone matures but is soft and porous
What causes osteomalacia/rickets?
Either insufficient calcium absorption (which can be caused by lack of vitamin D), or phosphate deficiency caused by increased renal losses
Which clinical features suggest post-traumatic osteomyelitis?
Non-union and poor wound healing
What is the modified Beighton score?
Measures hypermobility on a 9 point scale
What is the most common cause of septic arthritis in children?
Haemophilus influenzae (however now uncommon in areas where Haemophilus vaccination is practiced)
When would romosozumab be indicated in osteoporosis?
Recommended for postmenopausal women with severe osteoporosis who have had a fragility fracture and are at imminent risk of further fracture (24 months)
Which joints are affected in primary arthritis?
Weight-bearing or active joints - most commonly the knees, hands and hips
What is Paget’s disease of bone?
Chronic condition condition involving cellular remodeling and deformity of one or more bones
In intra-articular metaphases found in neonates and children (e.g. proximal femur), what co-existent condition can develop from osteomyelitis?
Septic arthritis
What empirical antibiotic would you give for a septic patient under 5 who has septic arthritis?
Flucloxacillin and ceftrioxine
Define generalised osteoarthritis
OA at either the spinal or hand joints and in at least 2 other joint regions
Describe the pathophysiology of osteoarthritis
Localised loss of hyaline cartilage and remodeling of adjacent bone with osteophyte formation at joint margins
Causes increased pressure and inflammation → pain, swelling, stiffness
How is a subperiosteal abscess able to form in infants?
Infants have loosely applied periosteum
Name an organism associated with prosthetic joint infection in upper limb prostheses
Cutibacterium acnes
What is secondary osteoporosis?
Osteoporosis that occurs secondary to other conditions e.g. corticosteroid use, alcohol abuse, malnutrition, endocrine disorders
Which bones are usually affected by Paget’s disease of bone?
Usually axial bones (small bones less commonly affected)
What is the most common cause of septic arthritis in adults?
Staph. aureus
Describe the non-pharmacological management of osteoarthritis
Exercise, weight loss, walking aids, physio, activity modification
What is the quantitative definition of osteopenia?
Intermediate stage before osteoporosis where bone mineral density is between 1 to 2.5 standard deviations below mean peak value
Describe the clinical presentation of osteoarthritis
Pain worse with activity, morning stiffness < 30 mins, night pain, inactivity gelling, instability
Name 3 risk factors for the development of primary osteoarthritis
Genetic predisposition, constitutional factors (e.g. female), biomechanics factors (e.g. occupational use)
What is osteomalacia?
Qualitative defect of bone with abnormal softening of the bone due to deficient mineralization of osteoid secondary to inadequate amounts of calcium and phosphorus
List three ways by which corticosteroids directly impact bone density
Reduction of osteoblast activity and lifespan
Suppression of replication of osteoblast precursors
Reduction in calcium absorption
What is primary hyperparathyroidism?
Hyperparathyroidism due to a benign adenoma, hyperplasia or rarely a malignant neoplasia
Which patient group is most likely to develop osteoporosis?
Post-menopausal women
Which investigations would you perform in suspected osteomalacia/rickets?
X-ray, bloods
What is septic arthritis?
Inflammation of the joint space caused by infection
What is the clinical marker of generalised osteoarthritis?
The presence of multiple Herbeden’s nodes
Neisseria gonorrhoea is a common cause of septic arthritis in which patient group?
Young adults
Name two second-line treatments used in osteoporosis
Zoledronic acid, desunomab
Why is a vertebral body fracture in a patient with osteoporosis often not identified at the time of injury?
Stress can be minimal e.g. coughing
Which investigation would you perform to exclude a malignancy from a patient presenting with vertebral fractures where you suspect osteoporosis?
Protein electrophoresis and Bence Jones proteins - to rule out multiple myeloma
