Neer classification of clavicle fractures

The Neer classification of clavicular fractures along with the AO classification system is one of the more frequently used classification systems when assessing clavicular fractures.

Classification

The classification system, broken into five categories communicates both the stability and treatment recommendation of the fracture focusing on the relationship of the fracture to coracoclavicular ligaments and the acromioclavicular joint.

Type I

Considered a stable fracture requiring nonoperative treatment

• minimally displaced fracture line sits lateral to the coracoclavicular ligaments
• trapezoid and/or conoid ligament intact

Type IIa

Considered an unstable fracture requiring operative treatment

• fracture is medial to the coracoclavicular ligament with significant displacement of the medial portion
• conoid ligament intact
•  trapezoid ligament intact

Type IIb

Considered an unstable fracture requiring operative treatment

• the fracture occurs between coracoclavicular ligament resulting in the conoid ligament torn and the trapezoid ligament intact
• displacement of the medial clavicle 

Type III

Considered a stable fracture requiring nonoperative treatment

• intra-articular distal clavicular fracture extending into the acromioclavicular joint
• conoid ligament intact
• trapezoid ligament intact

Type IV

Salter-Harris type I physeal fracture considered stable fracture requiring nonoperative treatment

• medial portion clavicle becomes displaced in the superior direction as the periosteal sleeve becomes avulsed from the inferior cortex
• conoid ligament intact
• trapezoid ligament intact

Type V

Considered an unstable stable fracture requiring operative treatment

• comminuted fracture with medial clavicle displacement
• inferior clavicle fragment attached to the coracoclavicular ligament
• conoid ligament intact
• trapezoid ligament intact