Category Archives: Adult Deformity

A = yield strength  D = ultimate tensile strength  Strain = the quantification of the deformation resulting from stress on a material (dL/L = strain)  Stress = force per unit area. Can mentally just think of it as force  Elastic Region  Once the force is remove, it will return to original length  The amount ofContinue reading “Stress Strain Curve”

Background  Coronal imbalance – 10 degrees  Sagittal (see preivous) SVA 5cm positive or negative  Coronal Deformity Types  Residual AIS  Classic patterns  More segments  Degenerative de novo adult scoliosis  Non classic pattern  Fewer vertebral segments, smalle curve  Presentation  Back pain   Spondylosis, discogenic  Neurogenic claudication  Stenosis  Radicular  Concave side  Imaging  PA 3 foot standing  Lateral   Sagittal assessment  DEXA – boneContinue reading “Adult Scoliosis  “

Summary Describe: – relative displacement of vertebraeTypes: Wiltse classification– Dysplastic (congenital)– Isthmic – Lytic – fatigue fracture of pars – Degenerative – Traumatic (fracture other than pars) – Pathologic – Iatrogenic Diagnosis:– History: trauma, chronicity, surgical history, age of presentation, concurrent medical problems– Imaging: spinal XR (AP and lateral)Management:– Non-operative– operative indication Wiltse Types  Dysplastic (congenital)   sacrum/ nerual arch, normal pars  Isthmic Continue reading “Spondylolisthesis”

Principles  Anchor point above and below  HD stability  Assume 2L blood loss  If over, stage it  Neuromonitoring  Flexible vs Rigid Deformity  Flexible  Compression/ distraction  Posterior column osteotomies (SPO)  Rigid deformity  Rigid with mobile disc: SPO  Rigid ankylosed sagittal: PSO, VCR  Rigid ankylosed coronal: asymmetric PSO, VCR  Spectrum of Osteotomies  Ponte  For thoracic kyphosis  Posterior shorten Continue reading “Osteotomies and Principles”

Background  Rigid spinal kyphosis cause by anterior wedging  Definition: Thoracic kyphosis with anterior wedging >5 degrees of at leas 3 consecutive vertebral bodies  Adolescents (onset age 10)  M>F  Autosomal Dominant  2 forms  Typical  Apex T6-8, curve T1-L1  Non structural lumbar hyperlordosis  Atypical  Apex TTL  More progressive and sympomatic  Pathophys  Unknown  Osteonecrosis of anterior apophyseal ring  Herniation of disc material leadingContinue reading “Scheuermann’s Kyphosis”

Importance of Sagittal Alignment  Cone of Economy (Conus of Debousset)  Narrow range in shape of cone formed between the head and the pelvis  Outside this cone – energy consumption to maintain upright posture goes up  Sagittal malalignment (PT >25 SVA >5) main driver of HRQOL and construct failure after spine surgery  Glassman et al  Linear relationshipContinue reading “Sagittal Alignment”

Background  Rigid spinal kyphosis cause by anterior wedging  Definition: Thoracic kyphosis with anterior wedging >5 degrees of at leas 3 consecutive vertebral bodies  Adolescents (onset age 10)  M>F  Autosomal Dominant  2 forms  Typical  Apex T6-8, curve T1-L1  Non structural lumbar hyperlordosis  Atypical  Apex TTL  More progressive and sympomatic  Pathophys  Unknown  Osteonecrosis of anterior apophyseal ring Continue reading “Scheuermann’s Kyphosis”

Importance of Sagittal Alignment  Cone of Economy (Conus of Debousset)  Narrow range in shape of cone formed between the head and the pelvis  Outside this cone – energy consumption to maintain upright posture goes up  Sagittal malalignment (PT >25 SVA >5) main driver of HRQOL and construct failure after spine surgery  Glassman et al  LinearContinue reading “Sagittal Alignment”