summary Myelodysplasia is a common group of congenital disorders caused by various chromosomal abnormalities that lead to the failure of closure of the fetal spinal cord and present with anatomic anomalies and neurological impairment of varying degree. Diagnosis can be made in utero with fetal ultrasound. Treatment involves a multidisciplinary approach to address neurological, genitoturinary, and orthopedic manifestations. Epidemiology Demographics 0.1-0.2% incidence Risk factors folate deficiency supplementation can decrease risk by 70% maternal hyperthermia maternal diabetes valproic acid Etiology Genetics chromosomal abnormalities up to 10% of fetuses have a chromosomal abnormality login to view 4 more bullets Associated conditions orthopaedic manifestations pathologic fractures spine deformities login to view 2 more bullets hip dysplasia login to view 2 more bullets knee deformities login to view 2 more bullets foot deformities neurosurgical manifestations Type II Arnold-Chiari malformation login to view 1 more bullet hydrocephalus login to view 1 more bullet tethered cord urological manifestations neurologic bladder Special considerations IgE mediated latex allergy results in profound anaphylaxis present in 20 to 70% of patients with this disorder Classification Forms of myelodysplasia spinal bifida oculta defect in vertebral arch with confined cord and meninges meningocele protruding sac without neural elements myelomeningocele protruding sac with neural elements rachischisis neural elements exposed with no covering Function level (described by lowest functioning level) Function level (described by lowest functioning level) Level Function Primary Motion Primary Muscles L2 Nonambulatory L3 Marginal Household ambulator High risk of hip dislocation Hip flexion Hip adduction Iliopsoas (lumbar plexus, femoral n.) Hip adductors (obturator n.) L4 Household ambulator plus Key level because quadriceps can function Knee extension Ankle dorsiflexion & inversion Quadriceps (femoral n.) Tibialis anterior (deep peroneal n.) L5 Community ambulator Toe dorsiflexion Hip extension Hip abduction EHL (deep peroneal n.) EDL (deep peroneal n.) Gluteus med.& min. (superior gluteal n.) S1 Normal ambulator Foot plantar flexion Gastroc-soleus (tibial n.) S2 Normal ambulator Toe plantar flexion FHL (tibial n.) S3,4 Normal ambulator Bowel & bladder function Imaging Radiographs useful for monitoring scoliosis/kyphosis hip dysplasia pathologic fractures MRI change in neurologic exam prompts urgent MRI to rule out cord tethering Studies Labs alpha-fetoprotein (AFP) elevated in 75% of children with open spina bifida obtain during second trimester Pathologic Fractures Introduction fractures of the long bones are common due to osteopenia frequency increases with the higher the level of the defect common in hip and knee in children ages 3 to 7 years of age fractures are often confused with infection osteomyelitis cellulitis Treatment short period of immobilization in a well-padded splint indications login to view 1 more bullet technique login to view 5 more bullets Scoliosis Introduction may result from muscle imbalance (neurogenic) or congenital malformation (e.g., hemivertebrae) login to view 1 more bullet higher the functional level, the greater the incidence of scoliosis 100% scoliosis rate with defects in thoracic levels consider cord tethering in rapidly progressing deformities Treatment nonoperative bracing not effective operative ASF and PSF with pelvic fixation login to view 9 more bullets Congenital Kyphosis Introduction present in 10-15% with myelodysplasia usually congenital and progressive Physicalexam Gibbus deformity may cause recurrent skin breakdown due to pressure points when sitting Treatment operative kyphectomy with fusion and posterior instrumentation login to view 5 more bullets Hip Disorders Hip dislocation introduction most common at L3 level due to unopposed hip flexion and adduction treatment nonoperative login to view 4 more bullets operative login to view 2 more bullets Hip abduction contracture introduction can cause pelvic obliquity and scoliosis treatment proximal division of fascia lata and distal iliotibial band release (Ober-Yount procedure) login to view 2 more bullets Hip flexion contracture introduction common in high lumbar or thoracic defects treatment anterior hip release with tenotomy of the iliopsoas, sartorius, rectus femoris, and tensor fascia lata login to view 2 more bullets Knee Disorders Weak quadriceps introduction common condition affecting children with myelodysplasia treatment KAFO (knee-ankle-foot orthotic) Flexion contracture introduction not as important to treat in wheelchair bound patients treatment hamstring lengthening +/- posterior capsulotomy login to view 2 more bullets supracondylar extension osteotomy login to view 3 more bullets Extension contracture introduction less common than flexion contractures treatment serial casting login to view 4 more bullets Tibial rotational deformities (torsion) treatment observation and orthotics login to view 2 more bullets distal tibial derotational osteotomy login to view 2 more bullets Foot and Ankle deformities Introduction very common 60 - 90% incidence due to high incidence of lower nerve root involvement Myelodysplasia foot deformity by level Level Foot Deformity Proper orthosis L1 & L2 Equinovarus HKAFO L3 Equinovarus KAFO L4 Cavovarus AFO L5 Calcaneovalgus AFO S1 Foot deformity shoes Clubfeet (talipes equinovarus) introduction 30% incidence with myelodysplasia login to view 1 more bullet very rigid insensate in the foot (different from idiopathic clubfeet) treatment serial casting login to view 4 more bullets posteromedial lateral release login to view 4 more bullets Foot dorsiflexion deformity introduction seen with L5 or sacral level patients unopposed anterior tibialis causes dorsiflexion deformity treatment posterior transfer of the anterior tibial tendon login to view 2 more bullets Vertical talus Prognosis Survival and neurologic impairment depend on level of spinal segment involved Untreated infants have a mortality rate of 90-100% Ability to ambulate L3 or above are mostly confined to a wheelchair L5 level patients have a good prognosis for independent ambulation Poor prognosis if tibiotalar valgus deformity is missed preoperatively Mutlidiciplinary team approach reduces postoperative complications