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Home > Adult Spinal Deformities (ASDs) – Part II – Healthy & Abnormal Curvature & Scoliosis

Adult Spinal Deformities (ASDs) – Part II – Healthy & Abnormal Curvature & Scoliosis

Dr. Jeffrey Carlson

Jeffrey R. Carlson, MD, MBA, CPE, FAAOS

In Part I, I provided a brief anatomical lesson regarding the spine and discussed the reasons a person may get an adult spinal deformity.  In this article, I will discuss the types of deformities that can affect patients and how we classify them.

The healthy spine has three gentle curves, that help it stay balanced when bearing our weight and standing or walking erect. When looking at the spinal column from the side, you will see an inward curve at the neck or cervical spine (lordosis), outward at the thoracic spine (kyphosis) and inward at the lumbar spine (lordosis). See the illustration below for examples.


When the spine is abnormally curved when viewing it from the side, it is called a sagittal imbalance. There are four types:

  • Lordosis or hyperlordosis – seen in lumbar/lower back region
  • Kyphosis – hunchback appearance
  • Chin-on-chest-syndrome – extreme kyphosis so that chin rests on chest
  • Flatback – lumbar spine is flat without normal lordosis

Abnormal curvature of the spine, seen from the back, is called scoliosis. There are five classification types for scoliosis:

  • Congenital: a form of scoliosis present at birth
  • Infantile :scoliosis that occurs in patients 0–3 years old
  • Juvenile: scoliosis that occurs in patients 4–10 years old
  • Adolescent: scoliosis that occurs in patients 11–18 years old
  • Adult: adult scoliosis may be idiopathic or degenerative in cause (this is typically what I treat)

Scoliosis is also classified according to the area of the spine that is affected or according to the type of curvature; See the illustration below.

In Part III, I’ll continue this article series, by discussing what symptoms would be displayed by a patient who has ASD and how I would make a definitive diagnosis when seeing a patient in the office for a consultation.




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