Level 2 - MSK

Question 1

What is developmental dysplasia of hip?

Answer 1

• A spectrum of severity ranging from stable acetabular dysplasia to established hip dislocation

Question 2

Epidemiology of DDH?

Answer 2

• Affects 1-3% of newborns
• Females 6:1 males
• Left hip most commonly affected
• Bilateral in 1/3

Question 3

Risk factors for DDH?

Answer 3

o Sibling with DDH

o Vaginal deliveries, breech delivery

o Oligohydramnios

o Multiple pregnancy, prematurity

o Cerebral palsy

Question 4

Describe disease progression in DDH?

Answer 4

o Capsular laxity + shallow acetabulum

o Instability/subluxation/dislocation

o Muscle contracture

o Progressive acetabular dysplasia with a fibro-fatty substance filling the acetabulum (pulvinar); femoral head becomes hypoplastic

Question 5

What would parents notice in DDH? What is Galeazzi’s sign?

Answer 5

• Notice delayed walking, painless limp, limited abduction, increased falls
• Galeazzi sign – hips and knees flexed 90o, unilateral femoral shortening may signify hip dislocation

Question 6

What screening tool is performed to prevent missing DDH? When should furthe testing be performed?

Answer 6

o NIPE baby check at <48 hours and 6-8 weeks

o If high risk, baby should have USS at 2-4 weeks

o Barlow’s manoeuvre

 Screen for a dislocatable hip

 Gentle backward pressure to the head of each femur in turn

 A subluxable hip is suspected on palpable displacement

o Ortolani’s test

 Screens for dislocated hip

 Abduction and lateral rotation

 Move a posteriorly dislocated femoral head forwards into the acetabulum

 Palpable movement suggests that the hip is dislocated or subluxed, but reducible

Question 7

What imaging should be done in DDH and when?

Answer 7

o Dynamic USS (<4.5 months)

o Pelvic X-rays (>4.5 months) Shallow acetabulum with incd acetabular index and hypoplastic femoral head

Question 8

Prognosis of DDH?

Answer 8

• Most unstable hips stabilise spontaneously by 2-6 weeks, any hip that remains dislocatable or pathologically unstable requires prompt treatment

Question 9

What is the management of DDH in <6 months?

Answer 9

o Long-term splinting in flexion-abduction (Pavlik harness)

Question 10

What is the management of DDH in 6-18 months?

Answer 10

o Exam-under-anaesthetic and open/closed reduction followed by immobilisation in spica hip (casting)

Question 11

What is the management of DDH in >18 months?

Answer 11

o Open reduction with corrective femoral/pelvic osteotomies to maintain stability

Question 12

Complications in DDH?

Answer 12

• Re-dislocation, stiffness, blood loss, avascular necrosis
• Premature degenerative joint disease
• Lower back pain

Question 13

What is transient synovitis?

Answer 13

• Hip pain, swelling of joint often following a viral infection (recent URTI, gastric illness)

Question 14

How common is transient synovitis?

Answer 14

• Most common cause of acute hip pain in 4-10 year olds

Question 15

Risk factors for transient synovitis?

Answer 15

• Boys twice as likely
• HLABR7 in Reiter’s syndrome

Question 16

Symptoms of transient synovitis?

Answer 16

• Sudden onset pain in hip or limp
• No pain at rest, decreased ROM particularly internal rotation
• Referred pain to the knee
• Afebrile commonly, looks well
• Usually develops 2-4 weeks after a genitourinary or gastrointestinal infection

Question 17

DDx of transient synovitis?

Answer 17

• Septic Arthritis, Perthe’s disease, Slipped upper femoral epiphysis

Question 18

Investigations in transient synovitis? What must be excluded and how?

Answer 18

• Diagnosis of exclusion
• Blood - FBC, (elevated WCC, CRP, ESR, normocytic normochromic anaemia)
• Need to exclude septic arthritis

o Joint aspiration and blood cultures

o X-ray normal

o USS fluid in joint

Question 19

Management of transient synovitis? Complications?

Answer 19

• Bed rest, analgesia (NSAIDs)
• Usually resolves in a few days
• 3% develop Perthe’s disease

Question 20

Causative organisms in reactive arthritis?

Answer 20

o C. trachomatis and Chlamydia pneumoniae are the most frequent causative pathogens

o Enteric bacteria (Salmonella, Shigella, Campylobacter, Yersinia)

o Borrelia burgdorferi (Lyme’s disease)

Question 21

What is Reiter’s syndrome?

Answer 21

o Large joint oligoarthritis, urogenital tract infection and uveitis

Question 22

What is juvenile idiopathic arthritis?

Answer 22

• Joint inflammation presenting in children under the age of 16 years and persisting for at least six weeks in absence of any infection or other defined cause

Question 23

Epidemiology of juvenile idiopathic arthritis?

Answer 23

• Commonest chronic inflammatory joint disease in children
• 1 in 1000 children in the UK

Question 24

Subtypes of JIA?

Answer 24

o 7 distinct subtypes based on number of joints affected in first 6 months (polyarthritis >4, oligoarthritis <4 or systemic (fever and rash)

o Psoriatic and enthesitis & presence of RF and HLA B27 tissue are further subtypes

Question 25

Symptoms of JIA?

Answer 25

- Gelling (stiffness after periods of rest) - Morning joint stiffness and pain - Intermittent limp or deterioration of behaviour when doing activities - Swelling of joint, thickening of synovium - Bone overgrowth, digit length discrepancy

Question 26

What other symptoms are seen in JIA and in what classifications?

Answer 26

- Rheumatoid nodules, psoriasis, nail pitting (polyarthritis RF positive) - Systemic - fever, malaise, salmon rash, lymphadenopathy and hepatosplenomegaly (systemic arthritis) - Inflammation at tendon/ligament insertion (enthesitis arthritis)

Question 27

DDx of JIA?

Answer 27

- Septic arthritis - Osteomyelitis - Reactive Arthritis - SLE, sarcoid

Question 28

Investigations of JIA?

Answer 28

- Clinical diagnosis - Bloods o FBC (normocytic anaemia), elevated CRP/ESR o ANA, RF, HLA B27 useful for classification - Imagine o X-ray often normal in early JIA o USS - Aspirate if suspect septic arthritis

Question 29

Where should the management of JIA be done? What other healthcare professional is important?

Answer 29

- Managed in specialist rheumatology MDT - Physiotherapy to maintain function, encourage physical activity as much as possible

Question 30

Medical therapy in JIA?

Answer 30

o NSAIDs o Intra-articular corticosteroid injections (1st line in oligoarticular JIA) o Methotrexate (1st line if multiple joints affected or same joint injected \>3 times) (sulfasalazine/etanercept can be used instead) o Systemic steroids o Tocilizumab when steroids and methotrexate fail for polyarticular arthritis

Question 31

Surgical management of JIA?

Answer 31

o Joint replacement may be required

Question 32

Complications of JIA?

Answer 32

- Chronic anterior uveitis - Flexion contracture of joints - Growth Failures - Anaemia of chronic disease