MSK

Question 1

12yo girl, overweight

6m Hx of painful knee w/ limp

Tren

Answer 1

Slipped Upper Femoral Epiphysis

• Displacement of femoral head postero-inferiorly
• Need Tx to prevent avascular necrosis
• Seen in adolescents just before puberty (9-14)
• Bilateral in 20%
• RFs:
  
  • OBESE
  • Males
  • Metabolic endocrine disease (hypothyroid, hypogonad)
• Sx
  
  • Limp/hip pain ±referred to knee
  • Loss of internal rotation of hip
• Ix
  
  • Hip XR in AP + Frog-lateral
  • Trethowan sign: line of Klein does not intersect superior femoral epiphyses
• Mx
  
  • Don’t let pt. walk, analgesia + Immediate ortho referral
  • Surgical repair - Fixation of growth plate in its slipped position to avoid further slippage
• Complications
  
  • Avascular necrosis
  • Arthritis
  • Osteochondritis

Question 2

Short 6yo boy with with insidious onset limp + hip/knee pain + limb shortening

Guarding/spasm when rolling hip internally/externally

Hip XR shows increased density of femoral head

Answer 2

Perthe’s Disease

Avascular necrosis of femoral epiphysis

• Primary school BOYS 4-8yo (SUFE = 10-16yo)
• RFs:
  
  • Boys 5x more common
  • Hyperactivity
  • Short stature
• Ix
  
  • Hip XR shows increased density of femoral head
  • Then becomes “Fragmented/irregular”/”Flattened femoral head”
• Mx
  
  • Analgesia
  • Continue activities
  • Physio - stretching quads and hamstrings, strengthening quads, encrouage hip abduction
  • Educate about exacerbations + Mx
  • SURGERY if fail to respond to conservative Mx (MUST BE >6yo)
• Complications
  
  • Premature fusion of growth plates
  • Osteoarthritis

Question 3

10yo with 2m history of swollen joints + morning stiffness, gelling, intermittent limp.

O/E: Salmon coloured rash + Visual impairment. Swan neck deformity.

Answer 3

Juvenile Idiopathic arthritis

• Most common chronic inflammatory joint disease in children
• Persistent joint swelling >6months
• Presents <16yo, in absence of infectio or other defined causes
• 1 in 1000 (as common as epilepsy
• >7 clinical subtypes
  
  • Classification based on:
    
    • No. of joints affected in first 6m
    • Rheumatoid factor
    • HLA B27
• Mx
  
  • Specialist paediatric rheumatology MDT
  • PT + OT
  • Encourage activity/sports, as inactivity leads to deconditioning/disability/decreased bone mass
  • NSAIDs for pain + stiffness
  • Corticosteroids - useful adjunctive agents while waiting for effect of second-line agents - avoid if possible due to risk of growth suppression/osteoporosis
  • DMARDs if disease fails to respond
    
    • ​1st = oral/SC methotrexate
    • 2nd = sulfasalazine
  • TNF-a inhibitors
• Complications
  
  • Anterior uveitis
  • Joint damage
  • Osteoporosis
  • Growth failure

Question 4

4yo with 2 day Hx of painful hip

Able to weight bear on limb, Temp 37.9

Answer 4

Transient Synovitis

• Most common cause of acute hip pain or limp
• MUST EXCLUDE SEPTIC ARTHRITIS
  
  • Kocher criteria
    
    • Fever >38.5
    • Unable to weight bear
    • ESR >40
    • WCC >12
  • 3, 40, 93, 100% risk (up to 4 points)
• If <3yo + acute limp, URGENT hospital assessment
• Mx
  
  • Self-limiting
  • Bed rest
  • Analgesia as needed
  • Usually resolves after few days

Question 5

14yo boy presents with knee pain after football. Relieved by rest.

O/E swelling over tibial tuberosity

Answer 5

Osgood-Schlatter Disease (tibial apophysitis)

• Inflammation of patellar tendon insertion at knee
• Mx
  
  • Reassure this will resolve over time, but may persist until end of growth spurt
  • REDUCE or CHANGE sports, gradually increase activity levels as symptoms get better
  • Analgesia, Ice packs, Protective knee pads
  • Stretching quadriceps

Question 6

Pain after exercise

Catching/locking/giving way

Answer 6

Osteochondritis dissecans

Question 7

3yo with 1wk history of fever and knee pain

Swollen, tender, erythematous knee

Raised WCC, ESR

Answer 7

Osteomyelitis

• Infection of metaphysis of long bones - usually distal femur & proximal tibia
• Haematogenous spread (e.g. surgery, open wound)
• Staph aureus
• <5yo

Ix

• Septic screen
• Blood cultures
• Joint aspiration + MC&S
• XR or MRI of joint
  
  • XR normal until late disease

Mx

• ACUTE
  
  • Blood culture first THEN high-dose IV empirical Abx
  • Change regimen once MC&S results arrive
  • Switch to oral once clinical recovery
  • Immobilise affected limb
  • Surgical debridement if there is dead bone/biofilm
• CHRONIC
  
  • Staging using Cierny-Mader classification
  • Surgical debridement
  • IV Abx

Question 8

1yo with 1 day history of fever and swollen thigh. Warm, tender, erythematous.

O/E: Temp 38.9, Reduced range of movement, infant holds limb still. There is marked tenderness over head of femur.

Answer 8

Septic arthritis

• Infection of SYNOVIAL joint (osteomyelitis = bone)
• Hip = 75% of cases
• Commonly <2yo INFANTS - acutely unwell febrile child
  
  • ​Temp >38.5
  • Unable to weight bear
  • ESR >40
  • WCC >12
• Haematogenous spread

Ix

• Septic screen
• Blood cultures
• Joint aspirate + MC&S
• XR of knee
• MRI of knee

Mx

• IV Abx 2wks - then oral 4wks
  
  • Suspected Gram +ve = Vancomycin
  • Suspected Gram -ve = Ceftriaxone
• Joint aspiration to dryness PRN
• Joint washout + surgery may be needed

Question 9

9yo with 2wk history of swollen knee. Hx of GI infection a month ago.

O/E: Temp. 38.2, knee is swollen. Movement not affected. Normal bloods and XR.

Answer 9

​Reactive Arthritis

Most common arthritis of childhood.

• Transient joint swelling <6wks duration (ankle/knee)
• Preceding infection
  
  • Enteric bacteria - salmonella, shigella, campylobacter, yersinia
  • Viral infection
  • STIs
  • mycoplasma, borrelia burgdoferi/Lyme disease
• Low-grade fever <38.5

Mx = Self-resolving. NSAIDs for analgesia.