Pediatric Orthopaedics

 

Fractures in Children

 

·                 type of fracture

o       usually greenstick or buckle because periosteum is thicker and stronger

o       adults fracture through both cortices

·                 epiphyseal growth plate

o       plate often mistaken for fracture and vice versa

o       x-ray opposite limb for comparison

o       mechanism which causes ligamentous injury in adults causes growth plate injury in children

o       intra-articular fractures have worse consequences in children because they usually involve the growth plate

·                 anatomic reduction

o       gold standard with adults

o       may cause limb length discrepancy in children (overgrowth)

o       accept greater angular deformity in clilldren {remodeling minimizes deformity)

·                 time to heal

o       shorter in children

·                 always be aware of the possibility of child abuse

o       make sure mechanism compatible with injury

o       high index of suspicion. look for other signs, including x-ray evidence of healing fractures at other sites

 

Stress Fractures

 

Mechanism

·                 insufficiency fracture

o       stress applied to a weak or structurally deficient bone

·                 fatigue fracture

o       repetitive. excessive force applied to normal bone

·                 most common in adolescent athletes

·                 tibia is most common site

 

Diagnosis and Treatment

·                 localized pain and tenderness aver. the involved bone

·                 plain films may not show fracture for 2 weeks

·                 bone scan +ve in 12-15 days

·                 treatment is rest from strenuous activities to allow remodeling (can take several months)

 

Epiphyseal Injury


 

Slipped Capital Femoral Epiphysis (SCFE)

·                 type I Salter-Harris epiphyseal injury

·                 most common adolescent hip disorder, peak at pubertal growth spurt

·                 risk factors: male, obese, hypothyroid

 

Etiology

·                 multifactorial

o       genetic: autosomal dominant, blacks > caucasians

o       cartilaginous physis thickens rapidly under growth honnone (GH) effects

o       sex honnone secretion, which stabilizes physis, has not yet begun

o       overweight: mechanical stress

o       trauma: causes acute slip

 

Clinical Features

·                 acute: sudden, severe pain with limp

·                 chronic: limp with medial knee or anterior thigh pain

·                 tender over joint capsule

·                 restricted internal rotation, abduction, flexion

Whitman's sign: with flexion there is an obligate external rotation of the hip

·                 pain at extremes of ROM

 

Investigations

·                 x-rays: AP, frog-leg, lateral radiographs

 • posterior and medial slip

 • if mild slip, AP view may be normal or show slightly widened growth plate compared with opposite side

 

Treatment and Complications

·                 mild/moderate slip: stabilize physis with pins in current position

·                 severe slip: ORIF or pin physis without reduction and osteotomy after epiphyseal fusion

·                 complications: AVN (most common), chondrolysis, pin penetration, premature OA, loss of ROM

 

Developmental Dysplasia of the Hip (DOH)

·                 formerly called congenital dysplasia of the hip (CDH)

·                 due to ligamentous laxity, muscular underdevelopment, and abnormal shallow slope of acetabular roof

·                 spectrum of conditions that lead to hip subluxation and dislocation

o       dislocated femoral head completely out of acetabulum

o       dislocatable head in socket

o       head subluxates out of joint when provoked

o       dysplastic acetabulum, more shallow and more vertical than normal

·                 painless (if painful suspect septic dislocation)

 

Physical Examination

·                 diagnosis is clinical

o       limited abduction of the flexed hip ( <50-600)

o       affected leg shortening results in asymmetry in skin folds and gluteal muscles, wide perineum

o       Barlow's test (for dislocatable hip)

o       –flex hips and knees to 90° and grasp thigh

o       –fully adduct hips, push posteriorly to try to dislocate hips

·                 Ortolani's test (for dislocated hip)

o       initial position as above but try to reduce hip with fingertips during abduction

o       positive test: palpable clunk is felt (not heard) ifhip is reduced

·                 Galeazzi's Sign

o       knees at unequal heights when hips and knees flexed

o       dislocated hip on side oflower knee

o       difficult test ifchild <1 year

·                 false positive if congenital short femur

o       Trendelenburg test and gait useful ifolder (>2 years)

 

Investigations

·                 U/S in first few months to view cartilage

·                 follow up radiograph after 3 months

 

Treatment and Complications

·                 0-6 months: reduce hip using Pavlik harness to maintain abduction and flexion

·                 6-18 months: reduction under GA, hip spica cast x 2-3 months (if Pavlik harness fails)

·                 >18 months: open reduction; pelvic and/or femoral osteotomy

·                 complications

o       redislocation, inadequate reduction, stiffness

o       AVN of femoral head

 

Legg-Calva-Perthes Disease (Coxa Plana)

 

·                 self-limited AVN of femoral head. presents at 4-10 years of age

·                 etiology unknown, 20% bilateral, males> females, 1/10,000

·                 associations

o       family history

o       low birth weight

o       abnormal pregnancy/delivery

o       history of trauma to affected hip

·                 key features

o       AVN of proximal femoral epiphysis, abnormal growth of the physis, and eventual remodelling of regenerated bone

 

Clinical Features

·                 child with hip pain and limp

·                 tender over anterior thigh

·                 flexion contracture: decreased internal rotation, abduction of hip

 

Investigations

·                 x-rays

o       may be negative early

o       eventually, characteristic collapse of femoral head (diagnostic)

·                 subchondral fracture

·                 metaphyseal cyst

 

Treatment

·                 goal is to preserve ROM and preserve femoral head in acetabulum

·                 PT: