Musculoskeletal disorders Flashcards
Differentials for musculoskeletal disorders
developmental dysplasia of the hip (DDH)
skeletal dysplasia
Osteogenesis imperfecta
Fractures
Torticollis
leg-calve-pethes
Osgood-Sclatter disease
What is DDH?
CH 678: DEVELOPMENTAL DYSPLASIA OF THE HIP (DDH)
- spectrum of pathology in the devt of the immature hip joint
Classification
1. acetabular dysplasia – abN morphology and devt of the
acetabulum
2. hip subluxation – partial contact between the femoral head and acetabulum
3. hip dislocation – hip with no contact between the
articulating surfaces of the hip: typical or teratologic
Etiopatho
- due to increased laxity of the joint during devt, which
fails to maintain a stable femoroacetabular articulation
- hormonal, mechanical, and genetic factors: IUGR, LGA,
oligohydramnios, 1st pregnancy = crowding phenomenon
- (+)FHx
- L hip: MC affected
- Baby carrying is protective: hips flexed, abducted and
free to move
What are the clinical manifestations of DDH?
Neonate:
a. Barlow provocative maneuver – test to
dislocate a nonreduced hip. Knee and hip
flexed, gently push then adduct thigh,
applying a posteriorly directed force (push
in – push LOW)
b. Ortolani test – test to reduce/relocate a
displaced hip. Sign of the ball of the femoral
head moving in and out of the acetabulum.
Knee flexed, gently pull then abduct the hip
while lifting the trochanter with 2 fingers
(up then out, letter O).
2. Infant – >2nd-3rd MOL: limited hip abduction, apparent
shortening of the thigh, proximal greater trochanter,
asymmetry of gluteal or thigh folds
3. Galeazzi sign – shortening of the thigh
- Place hips 90 degrees of flexion and compare the
height of the knees, look for asymmetry
4. Klisic test – imaginary line between greater trochanter
and ASIS is elevated (rather than pointing to the
umbilicus)
5. Walking child – limp or waddling gait, leg-length
discrepancy. Affected side shorter, toe-walk
6. Excessive lordosis
Diagnostics for DDH
Dx
1. PE: preferred dx for 0-4wks (high false + in UTZ)
2. UTZ – dx modality of choice for 1-4mos old.
3. Pelvis XR, AP view – for >4-6mos old. The proximal
femoral epiphysis has ossified. Broken Shenton’s line.
Management of DDH
Mgt
1. NB, infant – Pavlik harness
- Normalize within 3-4wks
2. Closed reduction – 6mos-2yo
3. Open reduction - >2yo; with concomitant femoral
shortening osteotomy
Complications of DDH
Complication
1. Avascular necrosis of the femoral epiphysis – most
impt
- Hip most vulnerable before 4-6mos
2. Redislocation, residual subluxation, acetabular
dysplasia
What is skeletal dysplasia?
CH 704: SKELETAL DYSPLASIA
- Primary chondrodystrophy (metaphyseal dysplasia)
- Skeletal dysplasias are classified under 3 major
categories:
o Osteodysplasias: affect bone density à
osteopenia
o Chondrodysplasias: genetic cartilage
disorders à deficient linear growth
o Dysostoses: affect a single bone
Patho
- Autosomal dominant disorders characterized by abN in
cartilage and none growth à abN shape and size of
the skeleton and disproportion of the long bones,
spine, head
Clinical manifestations of skeletal dysplasia
CM
1. Primary chondrodystrophy - Bowing of the legs, Short stature, Waddling gait, NO abnormality in Ca, PO4 levels, ALP activity or Vit D metabolites
- Metaphyseal chondrodysplasia (Jansen type) – very rare. Cupped and ragged metaphyses, which develop mottled calcification at the distal ends of bone overtime, deformed spine with irregular growth
- Schmid type – less severe. Extreme bowing of the
lower limbs. Lifelong short stature. - Pyle disease/ metaphyseal dysostosis – defects in
endochondral bone formation and metaphyseal modeling. The long ends of bones are splayed
(Erlenmeyer flask defect). Not necessarily with short
stature. Leonine features.
What is osteogenesis imperfecta?
CH 701: OSTEOGENESIS IMPERFECTA
- “Brittle bone disease”
- MC genetic cause of osteoporosis/ General disorder of CT ds
- Structural/quantitative defect in type I collagen
- Pathology: abnormal osteoblast differentiation.
Increased number of active bone resorbing osteoclasts
- Classical OI: autosomal dominant
Diagnostics and management of skeletal dysplasia
Dx
1. Skeletal survey
2. Serum Ca, Ph, ALP, VitD – r/o metabolic causes
Mgt
Currently no known tx.
1. Refer to OT/PT, etc.
Clinical manifestations of Osteogenesis imperfecta
CM
Types (Silence Classification)
1. Type I (mild) – blue sclerae, recurrent fractures,
presenile hearing loss
- TRIAD: fragile bones, blue sclerae, deafness
a. Subtype A – absent dentinogenesis imperfecta (DI)
b. Subtype B – present DI
2. Type II (perinatal lethal) – stillborn/ dies in the 1st YOL
- Extreme fragility of the bones and CT
3. Type III (progressive deforming) – most severe nonlethal
form
- Triangular facies + relative macrocephaly
- XR: popcorn appearance at metaphyses
4. Type IV (moderately severe) – usually able to attain community ambulation
- Fracture rate decreases after puberty
5. Type V (hyperplastic callus)
6. Type VI (hyperosteoidosis mineralization defect) –
hyperplastic callus, calcification of interosseous
membrane of forearm, radiodense metaphyseal band
7. Type VII, VIII, IX (autosomal recessive) – white sclerae,
rhizomelia, small to N head circumference
8. Type X, XI (autosomal recessive) – maybe mild
(Kuskokwim syndrome) to moderate severe (skeletal
fragility)
9. High bone mass OI (cleavage of the procollagen
peptide-C) – normal stature, white sclerae and teeth,mild to mod OI.
Diagnosis of OI
Dx
1. DNA sequencing
2. Skeletal survey – severe osteoporosis, deformed,
gracile (overtubulated) bones, cortical thinning,
hyperplastic callus, popcorn calcification (metaphyses
and epiphyses exhibit numerous scalloped radiolucent
areas with sclerotic margins), zebra stripe sign (cyclic
bisphosphonate tx produces sclerotic growth recovery
lines in the long bones), formation of pseudoarthrosis
at sites of healing fractures
Management of OI
No cure.
1. Bisphosphonates – decrease bone resorption by
osteoclasts
2. PT/OT, Ortho
3. Genetic counseling
FRACTURES
Unique Features of Pediatric fractures:
- Fracture remodeling – 3 major factors on angular correction:
a. Skeletal age
b. Distance to the joint
c. Orientation to the joint axis
- Best when:
o Fracture occurs close to the physis
o Child has more growth remaining
o Less deformity to remodel
o Adjacent to a rapidly growing physis - Skeletal maturity: F = 13-15yo; M = 14-17 yo
- Overgrowth – result of physeal stimulation from hyperemia associated with fracture healing
- Growth acceleration usually 6mos-1 yr after injury
- Results in equal/near equal limb length (<2cm) - Progressive deformity – MC due to complete/partial closure of growth plate
- Results to angular deformity and/or shortening - Rapid healing – due to thicker, more active periosteum
Clinical manifestations of fracture
CM
Fracture Patterns
1. Plastic deformation – unique to children. Fracture
results from force producing microscopic failure on
tensile side of bone and does not propagate to concave
side. The bone is angulated beyond its elastic limit.
- Permanent
- MC: ulna
- Bend in ulna <20 degrees in 4yo corrects with growth
2. Buckle/Torus fracture – occurs at junction at
metaphysis and diaphysis
- MC: distal radius
- Inherently stable. Heal in 3-4 weeks
3. Greenstick fracture – failure on the tensile/convex
side, not on concave side
4. Complete fracture – spiral, transverse, oblique
5. Epiphyseal fractures – MC: distal radius
