= Developmental disorders of chondro-osseous tissue

Common Orthopedic Problems Dwarfism

Short Stature Pathologic Short Stature Normal Variant Short Stature Proportionate Short Stature Midget Endocrine/nutritional Hypophosphatasia Dwarf Disproportionate Short Stature Short-Trunk Skeletal dysplasia Cretinism Short-Limb Rhizomelic Mesomelic Acromelic

Dwarfism Limb deformity

Dwarfism Limb deformity Spine deformity

Flexed Dwarfism Limb deformity Spine deformity C1-C2 instability Extended

Dwarfism Limb deformity Spine deformity C1-C2 instability Precocious osteoarthritis M/30; MED

Genetic Defects in Skeletal Dysplasia Matrix protein Type I collagen : OI, EDS type VII Type II collagen : SEDC, Kniest, Stickler Type III collagen : EDS Type IX collagen : MED Type X collagen : MCD Schmid type Type XI collagen : Stickler, OSMED COMP : PsACH, MED Fibrillin : Marfan

Receptor FGFR3 : ACH, HCH, TD PTH/PTHrP receptor : MCD Jansen type GNAS1 : McCune-Albright syndrome Transcription factor Cbfa1 : CCD Others Cell memb sulfate transporter : DTD Enzymes : MPS

Achondroplasia Pseudoachondroplasia Multiple epiphyseal dysplasia Metaphyseal chondrodysplasia, Schmid type Osteogenesis imperfecta Morquio disease

Achondroplasia Rhizomelic short-limb dwarfism (132/122cm) AD : FGFR-3 Typical face : clinical Dx at birth Normal intelligence and fertility

Orthopaedic Problems Hypotonia at infancy Short stature Thoracolumbar kyphosis at infancy Genu varum Spinal stenosis

Hypotonia at infancy Short stature Thoracolumbar kyphosis at infancy Genu varum Spinal stenosis

Management Posterior decompression for spinal stenosis Corrective osteotomy for limb deformity Limb lengthening Genetic counseling and prenatal diagnosis Growth hormone therapy : controversial Gene therapy (?)

Limb Lengthening in Achondroplasia Soft tissue tolerance Osteogenesis is not affected by the mutation. Unaffected articular cartilage Short-limb dwarfism Rare systemic problem & good intelligence Good Candidate

Type II Collagenopathy Mutation in type II collagen gene Axial skeleton >> distal extremity Short trunk dwarfism Associated with cleft palate, ocular problem Spondyloepiphyseal dysplasia congenita Kniest-Stickler dysplasia

A family with Kniest Dysplasia

Pseudoachondroplasia- Multiple Epiphyseal Dyplasia Family Gene COMP COL9A2 PsACH Disease COL9A3 MED MTLN3

Pseudoachondroplasia Normal at birth Short-limb dwarfism in 2 years Normal head and face Spondyloepimetaphyseal dysplasia

Pseudoachondroplasia Normal at birth Short-limb dwarfism in 2 years Normal head and face Spondyloepimetaphyseal dysplasia Short fingers without trident deformity Lower extremity angular deformity with ligamentous laxity Spine deformity Precocious osteoarthritis

Pseudoachondroplasia

Multiple Epiphyseal Dysplasia Slight to moderate short stature (145~170cm) Multiple epiphyseal dysplasia Short metacarpals and phalanges Scheuermann-like lesion in some cases

Multiple Epiphyseal Dysplasia Limb deformity LCP-like radiographs True AVN of the femoral head Precocious osteoarthritis

Orthopedic Problems Limb deformity LCP-like radiographs True AVN of the femoral head Precocious osteoarthritis

Metaphyseal Dysplasia Family Skeletal change confined to the metaphyses Heterogenous, genetically and phenotypically Schmid type Jansen type McKusick type Shwachman syndrome Others

MCD, Schmid type Mild to moderate short stature (130~160cm) AD: type X collagen gene mutation Bow leg with waddling gait in 2nd year

MCD, Schmid type Rickets-like radiologic finding Coxa vara, genu varum, rib flaring

MCD, Schmid type No precocious osteoarthritis Normal intelligence and life expectancy Candidate for limb lengthening

Osteogenesis Imperfecta Generalized osteoporosis frequent fracture Genetically and phenotypically diverse Mutation in type I collagen, in most cases

Classification Looser (1906) : congenita vs. tarda Shapiro (1985) Congenita Survival Ambulatory - A Long bone deformity (+) 6% 0% - B Long bone deformity (-) 92% 33% Tarda - A 1st fracture before walking 67% - B 1st fracture after walking 100% Sillence (1979)

Sillence Classification Type I: mild, AD, blue sclera Type II: perinatal lethal, AD or AR, blue sclera Type III: severe, AD (or AR), short stature, wheel-chair bound Type IV: intermediate, AD, variable Type V Type VI Type VII

Clinical Manifestation Fracture rare in neonatal period constant from childhood to puberty decreased incidence after puberty Joint laxity Blue sclera Sillence type I : distinctly blue throughout life DDx. : physiologic blue sclera at infancy

Clinical Manifestation Dentinogenesis imperfecta soft, translucent, brownish teeth Middle ear deafness in the 2 nd decade Cardiovascular Proportionate short stature

Radiologic Findings Generalized osteopenia Trefoil pelvis Misshapen skull Wormian bones Platyspondyly or codfish vertebrae

Radiologic Findings Generalized osteopenia Trefoil pelvis Misshapen skull Wormian bones Vertebral collapse

Management Acute fracture prevent malunion prevent aggrevation of osteoporosis internal fixation : IM nailing >> plate and/or screw

Multiple Osteotomy with IM Nailing

Bisphosphonate treatment : Suppress osteoclastic bone resorption Increase bone mineral density Decrease pain, fatigue, apprehension Decrease fracture frequency

Scoliosis Bracing : not effective Early fusion with segmental instrumentation technically demanding high operative risk

Mucopolysaccharidoses Group of genetic diseases with inborn error of mucopolyssachrides metabolism Common radiologic findings Dysostosis multiplex Various clinical manifestation Dx by enzyme assay AR in most diseases cf. XR in Hunter

Morquio Disease (MPS IV) Normal intelligence and life expectancy Short stature (<125cm) C1-2 instability Genu valgum

Orthopaedist for Skeletal Dysplasia Correct diagnosis A member of a team Orthopedic intervention Spine stabilization Deformity correction Limb lengthening Joint reconstruction Arthroplasty