Paeds - Orthopaedics

Question 1

Hip Pain

Differential Diagnoses
Clinical Features
Referral Criteria
Investigations

Answer 1

1. ) Differential Diagnoses
   - 0-4yrs: DDH, transient synovitis, septic arthritis
   - 6-10yrs: Perthes’, transient synovitis, septic arthritis
   - 10-16yrs: SUFE, septic arthritis, juvenile idiopathic arthritis (JIA)
2. ) Clinical Features
   - limp, pain, inability to walk, refusal to weight bear or use the affected leg, swollen or tender joint
   - red flags: fever, weight loss, anorexia, night sweats, fatigue, persistent pain, waking at night with pain, morning stiffness, swollen or red joint
3. ) Referral Criteria - for a limping child
   - child <3 yrs or >9yrs with a restricted or painful hip
   - severe pain or agitation, inability to weight bear
   - evidence of neurovascular compromise
   - suspicion of abuse
   - any of the red flags above ^^^
4. ) Investigations
   - bloods: inc CRP and ESR: septic arthritis, JIA
   - X-rays: fractures, SUFE and other boney pathology
   - US: used to establish an effusion (fluid) in the joint
   - joint aspiration: diagnose or exclude septic arthritis
   - MRI: used to diagnose osteomyelitis

Question 2

Developmental Dysplasia of the Hip (DDH)

Pathophysiology 
Risk Factors
Screening 
Diagnosis 
Management

Answer 2

1. ) Pathophysiology - structural abnormality in the hips caused by abnormal development of the fetal bones
   - this leads to instability in the hips and a tendency or potential for subluxation or dislocation
   - affects around 1-3% of newborns, more common in the left hip, can also be bilateral (20%)
2. ) Risk Factors
   - first-degree FH or hip problems in early life
   - breech presentation >36wks gestation, irrespective of presentation at birth or mode of delivery
   - multiple pregnancy
   - other: firstborn children
3. ) Screening - NIPE at birth and 6-8wks old
   - signs: different leg lengths, difference in the knee level during hip flexion, restricted hip abduction
   - CLUNKING of the hips on special tests:
   - Barlow: attempt to dislocate the femoral head posteriorly by pushing down on the knees at 90°
   - Ortolani: attempt to relocate a dislocated femoral head by abducting the hips, then pushing forward
   - DDH can be picked up later when the child presents with a limp, hip asymmetry, or reduced ROM in the hip
4. ) Diagnosis - ultrasound of the hips at 6-8weeks
   - carried out on any suspicion of DDH: positive Barlow or Ortolani, all children with risk factors above ^^^
   - USS is done at 6 weeks old
   - X-rays are first-line for infants >4.5 months old
5. ) Management
   - Pavlik harness if presenting at <6mths of age: kept on permanently for 6-8wks to hold the femoral head in the correct position, allowing the normal development
   - surgery: if harness fails or diagnosis after 6mths, after surgery, an hip spica cast is used to immobilise the hip for a prolonged period

Question 3

Perthes Disease

Pathophysiology
Clinical Features
Investigations
Management

Answer 3

1. ) Pathophysiology - disruption of blood flow to the femoral head, causing avascular necrosis of the bone
   - idiopathic and degenerative condition
   - more common in boys, aged 4-8 years (4-12 range)
   - over 2-3 years, healing of the femoral head occurs with bone remodelling which can lead to a soft and deformed femoral head –> early hip osteoarthritis
2. ) Clinical Features - should be no history of trauma
   - hip pain developing progressively over a few weeks
   - there may be referred pain to the groin or knee
   - limp, stiffness and reduced ROM of the hip
   - 10% of cases are bilateral
3. ) Investigations
   - hip X-ray: widening of joint space, decreased femoral head size/flattening, however, the X-ray can be normal
   - MRI or technetium bone scan if X-ray is normal
   - bloods are typically normal as it is non-inflammatory
4. ) Management
   - good prognosis in kids <6 so just conservative Mx to maintain good position and alignment in the joint to ↓the risk of damage or deformity to the femoral head
   - bed rest, traction, crutches, analgesia, physiotherapy
   - regular X-rays are used to assess bone healing
   - surgical correction in severe cases in children >6yrs
   - complications: OA, premature fusion of growth plates

Question 4

Slipped Upper Femoral Epiphysis (SUFE)

Pathophysiology
Clinical Features
Management

Answer 4

1. ) Pathophysiology - where the head of the femur is displaced (“slips”) along the growth plate.
   - more common in boys and obese children
   - peak onset at 12yrs (8-15), earlier in girls (11yrs)
2. ) Clinical Features - bilateral in 20% of cases
   - there may be a history of minor trauma that triggers the onset of symptoms, suspect SUFE if the pain is disproportionate to the severity of the trauma
   - presenting symptoms can be vague, these can be:
   - hip, groin, thigh or knee pain, painful limp
   - restricted hip ROM and movement in the hip
   - on examination, the hip is kept in external rotation, restricted internal rotation of the leg in flexion
3. ) Management
   - AP+lateral (frog-leg view) hip X-Ray is the diagnostic investigation
   - blood tests are normal (excludes other causes)
   - other imaging: Technetium bone scan, CT or MRI
   - treatment: surgical internal fixation to prevent further slipping

Question 5

Juvenile Idiopathic Arthritis

Pathophysiology
Systemic JIA
Other Subtypes of JIA
Management of JIA

Answer 5

1. ) Pathophysiology - idiopathic arthritis lasting more than 6 weeks in a patient under the age of 16
   - different subtypes with different characteristics and serology, the 5 key subtypes are:
   - systemic JIA, polyarticular JIA, oligoarticular JIA, enthesitis-related arthritis, juvenile psoriatic arthritis
2. ) Systemic JIA - aka Still’s disease (can also affects adults 15-25, 35-46)
   - high swinging fevers (>5d) worse in the evenings
   - joint and muscle inflammation and pain associated with the fevers
   - maculopapular salmon-pink evanescent rash: quickly disappears
   - weight loss, lymphadenopathy, splenomegaly
   - pleuritis and pericarditis
   - ↑CRP, ESR, plts and serum ferritin, -ve ANA and RF
   - life-threatening complication is macrophage activation syndrome –> DIC
3. ) Other Subtypes of JIA
   - polyarticular: affects >5 joints, ‘RA in children’
   - oligoarticular: <4 joints, often monoarticular, ANA +ve but RF -ve, associated with anterior uveitis
   - enthesitis-related: paediatric seronegative spondyloarthropathy, majority have HLA-B27 gene
   - psoriatic: will have signs of psoriasis
4. ) Management of JIA - paediatric rheumatologist
   - aim is to reduce inflammation within the joints, minimise sx and maximise function
   - 1°NSAIDs: to manage fever, joint pain and serositis, should be trialled for 1 week
   - 2°steroids (PO/IM or intra-articular): may control sx but doesn’t improve prognosis
   - 3°DMARDs: consider methotrexate, IL-1 or anti-TNF therapy

Question 6

Transient Synovitis

Pathophysiology
Clinical Features
Management

Answer 6

1. ) Pathophysiology - temporary irritation and inflammation in the synovial membrane of the joint
   - sometimes referred to as irritable hip
   - most common cause of hip pain in 3-10-year-olds
   - often associated with a recent viral URTI
2. ) Clinical Features - often occur within a few weeks of a viral illness, present w/ acute or gradual onset of:
   - limp, refusal to weight bear, hip or groin pain
   - mild low-grade temperature but otherwise well
   - may have mild knee effusion (seen on the US)
   - typically do not have a fever (joint pain with a fever must be managed as septic arthritis)
3. ) Management
   - self-limiting: rest, simple analgesia
   - must exclude septic arthritis
   - may be monitored in primary care if the child is:
   - 3-9yrs old, well, afebrile, mobile but limping, have had symptoms for less than 72 hours
   - safety netting: sx worsen or fever develops
   - prognosis: significant improvement after 24-48hrs, fully resolves within 1-2wks w/o any lasting problems, may recur in around 20% of patients

Question 7

Septic Arthritis

What is it?
Risk Factors
Clinical Features
Investigations
Management

Answer 7

1. ) What is it? - infection of a joint
   - main organisms: S. aureus, gonorrhoea, salmonella
   - bacteraemia, direct inoculation, from osteomyelitis
   - can cause irreversible articular cartilage damage
   - complications are severe OA and osteomyelitis
2. ) Risk Factors
   - age (>80), existing joint disease, immunosuppression
   - CKD, hip/knee prosthesis, IV drug use
3. ) Clinical Features
   - single swollen joint causing severe pain +/- pyrexia
   - red, swollen, warm, effusion may be present
   - unable to weight bear, pain on active and passive movement, the joint is rigid
   - septic arthritis can be subtle in young children, so is always considered in a child with joint problems
4. ) Investigations
   - routine bloods: ESR and urate levels,
   - blood cultures, esp in evidence of sepsis
   - joint aspiration before antibiotics given
   - X-ray: soft tissue swelling, fat pad shift, ↑joint space
   - CT/MRI if there’s an uncertain diagnosis
5. ) Management
   - empirical IV antibiotics until sensitivities are known, abx are usually continued for 3-6 weeks in total
   - irrigation and debridement for native joint