PUMC Classification and Solutions for Idiopathic Scoliosis

Idiopathic scoliosis refers to spinal curvature with no known cause, occurring during a child’s growth period. Beyond causing trunk deformities, collapse, and chronic pain, it significantly reduces labor capacity, restricts normal daily activities, and seriously impacts psychological well-being. In severe cases, it leads to lifelong disability, impaired quality of life, and social issues—for example, 76% of female patients remain unmarried. Early-onset or severe scoliosis can result in underdeveloped lungs, atelectasis, cardiopulmonary dysfunction, or even paraplegia, thus reducing life expectancy.

PUMC Classification

Peking Union Medical College (PUMC) classifies idiopathic scoliosis into 3 major types and 13 subtypes, each guiding a specific treatment strategy based on deformity complexity:

PUMC Type I – One apical vertebra

PUMC Type II – Two apical vertebrae

PUMC Type III – Three apical vertebrae

PUMC Type I – One apical vertebra

Ia – Thoracic curve                           Ib – Thoracolumbar curve                     Ic – Lumbar curve

Fusion Range and Surgical Approach

Ia – Posterior fusion, or thoracoscopic anterior approach

Ib – Anterior approach preferred
Ic – Anterior approach preferred

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PUMC Type II – Two apical vertebrae

IIa Double thoracic curve          IIb Thoracic curve greater than lumbar curve

IIc Thoracic curve ≈ Lumbar curve     IId Thoracic curve < Lumbar curve

Fusion Range and Surgical Approach

IIa (Double thoracic curve)

1, Fusion of both the upper thoracic and main thoracic curves is required if:

 • Upper thoracic curve > 30°

 • Bending film shows > 20°

 • Shoulders are level or the left shoulder is higher

2, Otherwise, posterior fusion of the main thoracic curve alone may be sufficient.

IIb Thoracic curve greater than lumbar curve

IIc Thoracic curve ≈ Lumbar curve

IId Thoracic curve < Lumbar curve

PUMC Type III – Three apical vertebrae

IIIa Distal curve meets the criteria of IIb1.  IIIb Distal curve meets the criteria of IIb2.

Fusion Range and Surgical Approach

IIIa: Posterior selective fusion of the proximal double thoracic curves, or fusion of the main thoracic curve only.

IIIb: Posterior fusion of all three curves, or fusion of the main thoracic and lumbar/thoracolumbar curves.

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Treatment Solutions for Idiopathic Scoliosis

Idiopathic scoliosis is commonly categorized by age of onset into:

● Infantile (0–3 years)

● Juvenile (3–10 years)

● Adolescent (10+ years)

Based on patient age, skeletal development, and deformity severity, different spinal fixation systems are selected for optimal results.

Atom Products:

4.5 Cobalt-Chromium-Molybdenum Pediatric Thoracolumbar Posterior Fixation System

Designed specifically for anatomical proportions of children, this system utilizes FGI (Functional Gradient Interface) coupling technology to achieve ultra-low notching and enhanced mechanical performance. A wide variety of hooks and growth rods provides highly personalized treatment options.

4.75 Cobalt-Chromium-Molybdenum Thoracolumbar Posterior Fixation System

Employing FGI technology, this system achieves ultra-low notching with improved biomechanical strength. Compared to traditional 5.5 mm titanium rod systems, its size is reduced by 27% while mechanical strength is tripled.

5.5 Cobalt-Chromium-Molybdenum Thoracolumbar Posterior Fixation System

Also featuring FGI technology, this system reduces overall volume by 15% compared to standard 6.0 mm titanium systems and enhances fatigue resistance by 229%.

About Atom

ATOM Medical Devices Co., Ltd. is a leading manufacturer of standardized orthopedic implants and instruments for global distributors and importers.

We offer a full product range covering trauma, spine, joints, sports medicine, and CMF — all supported by complete surgical instrument sets. Our products are designed for frequent orders, low MOQ, and fast turnaround, making them ideal for emerging markets and high-volume distribution.

With in-house R&D, a certified lab, and modern production lines, we also support OEM/ODM services for partners who need private label or custom solutions.

At ATOM, we focus on reliable, scalable manufacturing — so you can focus on growing your market.