Pediatric MSK

Apophyseal injuries

• Attachment site for muscle or tendon

• Acute injury - avulsion injury

  • Sudden onset pain + popping sensation

  • Decreased mobility of affected area

  • Anterior iliac spine and ischial tuberosity = most common sites

  • Seen with sports (i.e. track)

• Chronic - chronic microtrauma that is not strong enough to cause avulsion but will disrupt the growth plate

• Conservative management unless significantly displaced ( >1.5 cm)

Toddler Fracture

• Oblique fracture at distal tibia in kids starting to walk

• Refusal to bear weight

• May have history of stand and twist motion

• If this is seen in a child who is not walking in anyway then abuse should be considered

Ossification centers

• Elbow = CRITOE

  • Capitellum

  • Radial head

  • Internal epicondyle

  • Trochlea

  • Olecranon

  • External epicondyle

• Carpal Bones

  • Capitate 1-3 months

  • Hamate:  2-4 months

  • Triquetrium: 2-3 years

  • Lunate: 2-4 years

  • Scaphoid: 4-6 years

  • Trapezium: 4-6 years

  • Trapezoid: 4-6 years

  • Pisiform: 8-12 years

Dwarfism

Achondroplasia

• Autosomal dominant

• Ice cream scoop femur (dont really get this one)

• Frontal bossing (protruding forehead)

• Inverted V shaped physis (chevron sign)

• Metaphyseal flaring

• Square shaped iliac wings (tombstone sign)

• Genu varum

• Spinal deformities

• Short limbs

• Many findings

Hip US

• Graf classification

• Alpha angle

  • 60+ = always good

  • < 60 = ok if age is <3 months (13 weeks)

    • Obv if very low then bad

  • < 50 = ok in neonate as long as gradually increases to 60 by 3 months (13 weeks) old

• Want femoral head to be 50% or so seated within the acetabulum

• Who gets US - per ACR appropriateness criteria - Any child <4 months old w/

  • Positive physical exam findings

  • Equivocal physical exam findings

  • Females born breech

  • Family history of DDH

• US ideally done at 4-6 weeks

Developmental Dysplasia of the Hips

• Shallow acetabuli

  • Normal acetabular angle <30

• Femur can’t sit in acetabuli, uncovered laterally

• Sourcil (superior-lateral acetabular roof) is underdeveloped and not downturned

• Small osseous fragment that looks similar but not exactly like an os acetabuli due to mineralization of the labrum

• Wiberg angle

• Crowding in utero

  • Breech

  • Twins

  • Oligohydraminos

• F>M

Vertebral Plana

• Langerhans cell histiocystosis

• Medulloblastoma mets

Hips

Klein Line

• Line drawn along superior edge of the femoral neck

• Should intersect the superior aspect of the femoral epiphysis

  • If does not then concerning for SCFE

Blount Disease (Tibia vara)

• Stress on the posterior-medial physis results in suppression of growth at the proximal medial tibial physis

• Angulation is at the metaphysis NOT at the knee joint itself (although the knee joint is probably secondarily angled)

  • Growth plate slants medially

• Metaphyseal-diaphyseal Angle > 11 deg

• Can be unilateral or bilateral

• Results in genu varum

• Compensatory hypertrophy of the medial meniscus

• Age 2 and 12 years old

  • But never before age 2 years old

• Does not occur before walking

  • Thought to occur from too much weight on immature leg

  • Therefore typically does not occur before age 2

• Commonly bilateral

• RFs

  • Fat kids

  • Early walkers

Scurvy

• Wimberger Ring sign

  • Dense calcification surrounding the developing epiphysis

• Subperiosteal hemorrhage

• Generalized osteopenia

• Hemarthrosis

• Frankl line = dense line of calcification

• Trummerfield zone = lucent zone deep to Frankl line

• Pelkan spur = metaphyseal spur from healing microfractures

Periosteal reaction in Newborn

• Infection

  • Syphilis - seen around 2 months

  • Rubella - seen before 2 months

• Mets (neuroblastoma)

• Abuse

• Caffey’s

• Prostaglandin therapy

  • Look for heart with PDA clip or some other shit in heart

• Physiologic

  • Seen 3 months of age and should resolve before 6 months old

  • Proximal (femur) before distal (tibia)

  • Always involves diaphysis

Osetomyelitis

• Metaphysis is a septic tank

• Look for normal radiograph followed by lesion development a week or two later near metaphysis

• The physis is largely avascular so thought to act as a barrier to prevent spread from metaphysis to epiphysis

• Key Organsisms

  • Staphs aureus > Strep = most common for hematogenous osteomyelitis in kids

  • Kingella kingae = kids <4 years old, loves the epiphysis/epiphyseal cartilage, gram neg bacillus

  • Pseudomonas & E.coli = osteomyelitis from penetrating trauma, classically in the foot

• Chronic recurrent multifocal osteomyelitis

  • Multiple relapsing/remitting bones lesions

  • Kids & adolescents

  • Basically multifocal areas of edema on MRI, usually in long bones, lytic on XR

  • Also characteristically may involve the clavicle

  • Classically the metaphysis like regular osteo

  • Associated conditions

    • Psoriasis

    • Pyoderma gangrenosum

    • Wegeners

    • Takayasu

    • Majeed syndrome

    • SAPHI

Metaphyseal bands

• Lucent metaphyseal band =

  • Leukemia

  • Neuroblastoma

  • Rickets

  • Oseto

• Dense metaphyseal band

  • Lead

  • Chronic anemia (sickle cell, thalassemia)

  • Methotrexate use

  • Growth arrest band in juvenile RA

Engleman Disease

• Fusiform enlargement & sclerosis of long bones

• Spares epiphysis

• Hot on bone scan

• Autosomal dominant

Rickets

• Targets rapidly growing bones (knees, wrists)

• Cupping/fraying and widening of metaphysis - symmetric

• Demineralized Bone

• Not seen in newborns (still have Vit D from mom)

  • If you

Idiopathic Chondrolysis

• Progressive articular cartilage destruction of unknown cause

• Unilateral

• No systemic symptoms

• Inflammatory markers are normal

• Early imaging is normal

• Abnormal signal in middle third of femoral epiphysis

Wormian Bones DDx:

• Osteogenesis imperfecta

• Cleidocranial dysostosis

• Pyknodysostosis

Juvenile Idiopathic Arthritis (aka JRA)

• Rice bodies (necrotic small bodies) in joint space

  • Also seen in TB

• Age <16 yo + 6+ weeks of joint pain

• Nonspecific bone and cartilage damage

• Early growth plate closure

Lateral condylar fractures

• Ages 5-10 typically

• Varus injury to a supinated and extended forearm

• Crescentic rim along the condyle (what i thought was the epicondyle is apparently the condyle in kids)

• Most commonly SH-4 fxs

• Milch type 1 & 2 classifications

Non-accidental Trauma

• Fractures at different stages of aging

• Long bone fractures - not specific for NAT

• Specific findings for NAT

  • Metaphyseal corner fracture

  • Posterior rib fractures near costovertebral joint

  • Isolated subdural hemorrhage

  • Duodenal hematoma or post-traumatic pancreatitis in patient with otherwise no history of trauma

• Workup

  • Skeletal survey

    • Should comment on presence/absence of wormian bones

  • Consider bone scan

  • Head CT/MR

Fibromatosis Coli

• Benign masses in the sternocleidomastoid of neonates

• Looks like testicles in the neck

  • Looks like two round balls = two heads of the SCM muscle

• Goes away on its own

References: