Level 2 - MSK Flashcards
What is developmental dysplasia of hip?
- A spectrum of severity ranging from stable acetabular dysplasia to established hip dislocation
Epidemiology of DDH?
- Affects 1-3% of newborns
- Females 6:1 males
- Left hip most commonly affected
- Bilateral in 1/3
Risk factors for DDH?
o Sibling with DDH
o Vaginal deliveries, breech delivery
o Oligohydramnios
o Multiple pregnancy, prematurity
o Cerebral palsy
Describe disease progression in DDH?
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
What would parents notice in DDH? What is Galeazzi’s sign?
- Notice delayed walking, painless limp, limited abduction, increased falls
- Galeazzi sign – hips and knees flexed 90o, unilateral femoral shortening may signify hip dislocation
What screening tool is performed to prevent missing DDH? When should furthe testing be performed?
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
What imaging should be done in DDH and when?
o Dynamic USS (<4.5 months)
o Pelvic X-rays (>4.5 months) Shallow acetabulum with incd acetabular index and hypoplastic femoral head
Prognosis of DDH?
- Most unstable hips stabilise spontaneously by 2-6 weeks, any hip that remains dislocatable or pathologically unstable requires prompt treatment
What is the management of DDH in <6 months?
o Long-term splinting in flexion-abduction (Pavlik harness)
What is the management of DDH in 6-18 months?
o Exam-under-anaesthetic and open/closed reduction followed by immobilisation in spica hip (casting)
What is the management of DDH in >18 months?
o Open reduction with corrective femoral/pelvic osteotomies to maintain stability
Complications in DDH?
- Re-dislocation, stiffness, blood loss, avascular necrosis
- Premature degenerative joint disease
- Lower back pain
What is transient synovitis?
- Hip pain, swelling of joint often following a viral infection (recent URTI, gastric illness)
How common is transient synovitis?
- Most common cause of acute hip pain in 4-10 year olds
Risk factors for transient synovitis?
- Boys twice as likely
- HLABR7 in Reiter’s syndrome
Symptoms of transient synovitis?
- 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
DDx of transient synovitis?
- Septic Arthritis, Perthe’s disease, Slipped upper femoral epiphysis
Investigations in transient synovitis? What must be excluded and how?
- 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
Management of transient synovitis? Complications?
- Bed rest, analgesia (NSAIDs)
- Usually resolves in a few days
- 3% develop Perthe’s disease
Causative organisms in reactive arthritis?
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)
What is Reiter’s syndrome?
o Large joint oligoarthritis, urogenital tract infection and uveitis
What is juvenile idiopathic arthritis?
- 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
Epidemiology of juvenile idiopathic arthritis?
- Commonest chronic inflammatory joint disease in children
- 1 in 1000 children in the UK
Subtypes of JIA?
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
Symptoms of JIA?
- 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
What other symptoms are seen in JIA and in what classifications?
- 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)
DDx of JIA?
- Septic arthritis
- Osteomyelitis
- Reactive Arthritis
- SLE, sarcoid
Investigations of JIA?
- 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
Where should the management of JIA be done? What other healthcare professional is important?
- Managed in specialist rheumatology MDT
- Physiotherapy to maintain function, encourage physical activity as much as possible
Medical therapy in JIA?
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
Surgical management of JIA?
o Joint replacement may be required
Complications of JIA?
- Chronic anterior uveitis
- Flexion contracture of joints
- Growth Failures
- Anaemia of chronic disease
