Introduction Skeletal dysplasia affecting bones formed by intramembranous ossification. Epidemiology approximately 1 in 1,000,000 affected Pathophysiology caused by defect in intramembranous ossification leads to failure of formation of midline structures characteristic feature is hypoplastic or absent clavicles Genetics autosomal dominant RUNX2/CBFA1 mutation transcription factor which regulates osteoblastic differentiation Orthopaedic manifestations proportionate dwarfism clavicle dysplasia/aplasia wormian bones frontal bossing delayed fontanelle ossification due to delay in closure of skull sutures coxa vara shortened middle phalanges of 3-5 fingers delayed ossification of pubis dental abnormalities delayed eruption of permanent teeth Presentation Symptoms usually asymptomatic Physical exam hypermobility of the shoulders frontal bossing hand deformities examine middle phalanges for shortening delayed formation of permanent teeth abnormal range of motion at hips if severe coxa vara may be present Imaging Radiographs recommended AP chest to identify clavicular dysmorphism lateral skull look for delayed closure of sutures AP pelvis look for coxa vara look for failure of pubis to ossify AP hands short middle phalanges Treatment Nonoperative observation indications clavicular hypoplasia outcomes most manifestations associated with this disease do not need intervention Operative intertrochanteric osteotomy indications coxa vara with a neck shaft angle of less than 100 degrees
QUESTIONS 1 of 3 1 2 3 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ07.241) A heterozygous loss of function mutation in which of the following genes would result in cleidocranial dysplasia? Review Topic QID: 902 1 BMP-2 3% (19/746) 2 cAMP 4% (29/746) 3 c-fos 10% (74/746) 4 SOX-9 23% (171/746) 5 RUNX2 60% (449/746) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ05.105) An 8-year-old boy presents with extreme shoulder motion and frontal bossing. A chest radiograph and AP pelvis radiograph are shown. What is the most likely diagnosis? Review Topic QID: 991 FIGURES: A B 1 Cleidocranial dysplasia 93% (1753/1879) 2 Renal osteodystrophy 2% (32/1879) 3 Spondyloepiphyseal dysplasia tarda 4% (73/1879) 4 Hypothyroidism 0% (9/1879) 5 Bilateral slipped capital femoral epiphyses 0% (3/1879) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 1