Spinal Deformities

Overview of Spinal Deformities - Spine's Shape Shifters

• Spinal deformities: Abnormal curvatures/alignments of the vertebral column in coronal or sagittal planes.
• Normal Sagittal Curvatures:
  • Cervical lordosis (inward)
  • Thoracic kyphosis (outward)
  • Lumbar lordosis (inward)
• Key Deformity Types:
  • Scoliosis: Coronal plane; lateral curvature > 10° (Cobb angle), often with vertebral rotation.
  • Kyphosis: Sagittal plane; excessive posterior thoracic curvature ("roundback").
  • Lordosis: Sagittal plane; increased anterior lumbar curvature ("swayback").

⭐ Adam's forward bend test is a key screening tool for scoliosis, a common spinal deformity.

Scoliosis - The Lateral Curve Ball

• Definition: Lateral spinal curvature >10° (Cobb angle), often with vertebral rotation.

• Key Signs: Uneven shoulders/waist; Adams Forward Bend Test: rib/loin hump.

• Diagnosis:

  • Cobb Angle: $Cobb Angle = \alpha + \beta$ (angle between endplates of most tilted vertebrae).
  • X-ray (Full Spine AP/Lat): Curve magnitude, pattern, flexibility.
  • Risser Sign (0-5): Skeletal maturity (crucial for progression risk & treatment).

• Classification Highlights:

  Type	Key Points
  Idiopathic (80%)	Adolescent (AIS) most common; girls > boys.
  Congenital	Vertebral anomalies; often progressive.
  Neuromuscular	CP, MD; often severe, long C-curves.
  Other	Syndromic (Marfan's, NF1), Degenerative.

• Adolescent Idiopathic Scoliosis (AIS) Management: Goals: Halt progression, maintain trunk balance.

  • 📌 20-40-50 Rule (approx. for AIS):
    • Observation: Curves <20-25°. Regular follow-up until skeletal maturity.
    • Brace (e.g., TLSO): Curves 25-45° in skeletally immature (Risser 0-2).
    • Surgery (Spinal Fusion): Curves >45-50° (immature) or >50° (mature/progressive), or failed bracing.

⭐ In adolescent idiopathic scoliosis, curves <25° are typically observed, 25-45° in skeletally immature patients may require bracing, and >45-50° often indicate surgical consideration.

Kyphosis & Lordosis - Arch Enemies

• Kyphosis: Excessive posterior thoracic spine curvature. Normal: 20-45°.
• Lordosis: Excessive anterior lumbar spine curvature. Often physiological or compensatory.

⭐ Scheuermann's kyphosis is a rigid deformity characterized by vertebral wedging of ≥5° in at least three adjacent vertebrae and is often associated with Schmorl's nodes and tight hamstrings.

Spondylolisthesis - The Vertebral Slip-Up

Spondylolisthesis: Forward slip of one vertebra over an adjacent caudal vertebra. Most common at L5-S1 (isthmic) or L4-L5 (degenerative).

• Wiltse Classification (📌 DID TPI):

  • Type I: Dysplastic (Congenital sacral/L5 arch anomaly)
  • Type II: Isthmic (Pars interarticularis lesion; common in young athletes)
  • Type III: Degenerative (Facet/disc degeneration; older adults)
  • Type IV: Traumatic (Posterior element fracture, non-pars)
  • Type V: Pathologic (Bone disease: tumor, infection)
  • Type VI: Iatrogenic (Post-surgical)

• Meyerding Grading of Slip:

  Grade	Slip Percentage
  I	<25%
  II	25-50%
  III	50-75%
  IV	75-100%
  V	>100% (Spondyloptosis)

⭐ The 'Scottie dog' sign on oblique lumbar radiographs, where the 'collar' represents the pars interarticularis fracture, is characteristic of isthmic spondylolisthesis.

Symptoms: Low back pain (activity-related), radiculopathy, neurogenic claudication, tight hamstrings. Commonly affects L5-S1 or L4-L5 levels.

High‑Yield Points - ⚡ Biggest Takeaways

• Scoliosis: Cobb angle >10°; screen with Adam's forward bend test.
• Congenital scoliosis: linked to vertebral anomalies (e.g., hemivertebrae) and VACTERL.
• Adolescent Idiopathic Scoliosis (AIS): most common; Risser sign assesses skeletal maturity.
• Scheuermann's kyphosis: anterior wedging ≥5° (≥3 vertebrae), Schmorl's nodes.
• Spondylolisthesis: Meyerding grading; "scotty dog" sign for pars defect.
• Bracing for AIS: effective for curves 25-45° in skeletally immature.
• Scoliosis surgery: indicated for curves >45-50° or rapid progression.