Paediatric Orthopedics

Question 1

Differences between fractures in adults and children

Answer 1

• Fracture patterns – buckle fractures, plastic deformation and greenstick fractures occur in children, but not in adults because the mechanical property of immature bone is different. In mechanical terms, a child’s bone is less brittle.
• Time to healing – femoral fractures heal in “age in years + 1” weeks, physeal fractures heal in 2-3 weeks. Adult fractures heal much more slowly. The process of fracture healing uses many of the pathways used in growth of long bones.
• Remodelling – Capacity for remodelling can be impressive. Is more predictable in children <8yrs of age, fractures close to a joint, and where the residual deformity is in the plane of the joint. Proximal humeral fractures remodel well. Rotational deformities of any fractures do not remodel.
• Treatment differs – the rationale for treating a lot of adult fractures operatively relates to the fact that adults suffer “complications of immobility”. These include joint stiffness, osteoporosis, pressure sores, UTI, DVT, and confusion which are extremely uncommon in children. Fracture treatment relies more on plaster casts and percutaneous fixation with fine wires than in adults, where the principles of rigid internal fixation are more commonly applied.

Question 2

Legg-Calve-Perthes Disease

Answer 2

• Commonly occurs in boys 4-8 years
• Necrosis of part of the femoral capital epiphysis, a growth disturbance in the physeal and atricular cartilage which can lead to deformity of the femoral head and degenerative joint disease.
• Presents with groin (knee) pain, a limp and often a reduction in hip abduction and internal rotation.
• X-rays usually show asymmetry of the femoral capital ossific nucleus, while affected side smaller or in more advanced cases fragmented.
• Treatment usually involves est and possibly casts or surgery.

Question 3

Sliped Upper/Capital Femoral Epiphysis (SUFE/SCFE)

Answer 3

• Occurs in early adolescence
• Aetiology may relate to period of rapid growth and obesity
• Can be associated with hypothyroidism, CKD, previous radiotherapy and growth hormone therapy
• Usually insidious onset of hip pain (often referred to knee) and limp
• Affected limb is externally rotated and often shortened
• Diagnosis made by X-ray including frog leg projection
• Treatment by in-situ pinning

Question 4

Red flags for NAI

Answer 4

• Points to consider
  
  • Is the history variable or inconsistent with the injuries seen?
  • Was there a delay in seeking attention following an injury?
  • In a limping child – could this be due to a fracture or soft tissue injury? Is there a history of trauma, and is it consistent with the injury?
  • Are there multiple injuries?
  • Are there multiple attendances to the Emergency department, primary care or other healthcare services?
  • Are there signs of neglect, such as an unkempt, persistently dirty or smelly child - and especially in a child with learning difficulties or chronic illness?
  • Are the findings consistent with the developmental age of the child?
• Patterns in NAI include:
  
  • Bruising in a non-mobile child.
  • Bruising over soft tissues, multiple bruises, clusters of bruises, bruises in the shape of a hand or implement or instrument.
  • Burns in particular shapes eg cigarette burns, burns suggestive of forced immersion.
  • Exclude bruising or soft tissue swelling due to medical causes – eg vasculitis, coagulation disorders.
  • Exclude metabolic bone disease with recurrent fractures (e.g osteogenesis imperfecta or osteoporosis secondary to chronic corticosteroids).
  • Remember a child with an organic diagnosis and especially chronic illness or disability may still be at risk of abuse or neglect.
  • Certain types of fractures are more suggestive of abuse than others (although none are pathognomonic) e.g. classic metaphyseal lesions, usually caused by twisting/shearing forces, posterior rib fractures (from squeezing), skull fractures.
  • Any fracture in a non-mobile child should raise concern about NAI.

Question 5

Developmental Dysplasia of the Hip (DDH)

Answer 5

• Neonatal hip instability, acetabular dysplasia with or without subluxation and frank dislocation of the hip joint
• Painless but can lead to arthritis of the hip in early adulthood
• Risk factors include:
  
  • Female sex
  • FHx of DDH in 1st degree relative
  • Breech presentation after 35 weeks gestation
  • Foot deformity
• All babies screened at 6 week baby check - abnormal assessed using US
• Baby check includes:
  
  • Risk factors
  • Examination of asymmetrical groin creases
  • Leg length discrepancy
  • Range of hip abduction reduced
  • Instability tests of Barlow and Ortolani
• Diagnosis easier at birth
• Prompts splintage for around 12 weeks
• Diagnosis in older children moer likely to involve casts or surgery
  
  • Open reduction
  • Osteotomies of femur/pelvis

Question 6

Talipes equinovirus (Club foot)

Answer 6

• Deformity of the ankle (tal) and foot (pes) which results in the heel pointing downwards (equinus) and inwards (varus) and the sole pointing medially - talipes equinovarus or clubfoot.
• May be fixed, or positional (a normal foot held in an abnormal position in the uterus)
• Positional talipes (where all components of the deformity can be corrected in the newborn) can be treated by stretching by the parents
• Fixed clubfoot may be isolated (75%) or associated with other abnormalities
• The vast majority of feet are treated with the Ponseti technique (initially plaster casts changed weekly, most require cutting of the Achilles tendon, then an abduction foot orthosis initially used full-time and then part-time until age 4 with only a minority needing surgery).

Question 7

Scoliosis

Answer 7

• A lateral curvature of the spine (scoliosis) is the most common deformity of the spine in childhood.
• Some may be secondary to a leg length inequality. Others are associated with neuromuscular conditions (DMD or cerebral palsy), but the majority are idiopathic and may represent a disturbance in the growth of the spine.
• They most commonly present at around the time of accelerated growth in puberty.
• The treatment depends on many factors such as the underlying cause, the magnitude and type of curve, the cosmetic effect and the potential of the deformity to increase.

Question 8

Red flags of back pain in children

Answer 8

• Under 4 years old
• Night pain
• Functional disability
• Postural shift
• Lasting more than 4 weeks
• Limitation of movement due to pain
• Neurological signs

Question 9

Normal variants (remember the 5 S’s)

Answer 9

• If a child presents with a Symmetrical deformity, with no Symptoms, underlying Systemic illness or Skeletal dysplasia and there is no Stiffness on examination then it is likely that they have a normal variant.
• Osgood Schlatter’s syndrome – this is a common overuse syndrome which usually occurs in boys around the age of 11 or 12 who are physically active. The pain is felt discretely over the tibial tuberosity at the insertion of the patellar ligament and may be accompanied by swelling and local tenderness. If the pain and tenderness is NOT over the tibial tuberosity then more serious causes should be excluded. Managed by activity restriction and the natural history is resolution of symptoms at skeletal maturity.
• Anterior knee pain – the exact cause is unknown. A minority are associated with patellar tracking abnormalities occurring with knee movements. The pain is felt on the front of the knee and may radiate to the back of the joint. It is aggravated by activities such as squatting, stairs and sitting with the knee flexed for prolonged periods of time. Tenderness over the articular surface of the patella may be present. The management involves activity modification to avoid the precipitating factors, and quadriceps strengthening exercises. Anterior knee pain tends to come and go through adolescence and young adulthood but usually responds to resumption of quads exercises and activity modification.
• Irritable hip - transient synovitis
• Pulled elbow – a condition of toddlers noted after an acute episode of longitudinal traction to the arm. The child cries and refuses to move the elbow. Fractures must be excluded. In this condition the radial head partially slips from the enfolding annular ligament. Reduction is effected by supination and pronation of the forearm with the elbow flexed.

Question 10

Rickets

Answer 10

• Vitamin D deficiency – lack of light+/- lack dietary Vit D
• Calcium deficiency- reduced absorption e.g. coeliac, inflammatory bowel disease
• Hypophosphataemic (vitamin D resistant) Impaired parathormone dependent proximal renal tubular resorbtion of phosphate
• Vitamin D dependent rickets
  
  • Type 1 Defect in renal-1 hydrolase
  • Type 2 End organ unresponsiveness to 1,25 vit D3
• Hypophosphatasia