Table 3.

Treatment algorithm for atlas fractures according to Gehweiler classification [16]

Gehweiler classification	Location of the fracture	Treatment
Type I	Isolated fracture of the anterior arch	Immobilization for 6 weeks with rigid collar
Type II	Isolated, predominately bilateral, fracture of the posterior atlas ring	Immobilization for 6 weeks with rigid collar
Type IIIa	Combined injury of the anterior and posterior arch of the atlas with TAL intact (stable)	Rigid collar with a tight follow-up to exclude dislocation, nonunion, and/or sign of atlantoaxial instability
Type IIIb	Combined injury of the anterior and posterior arch of the atlas with TAL damage (unstable)	Dickman I: C1-2 posterior fusion
		Dickman II: If minimal displaced bony avulsion of the TAL: direct osteosynthesis of the atlas or halo-traction for 6 to 12 weeks. If severe dislocated bony avulsion of the TAL: C1–2 posterior fusion
Type IV	Fractures of the lateral mass	Conservatively with a hard cervical collar
		If significant dislocation of the fractured lateral mass: reduction under traction for 6 to 12 weeks in a halo-vest. In case of failure: surgery with posterior occipitocervical stabilization
Type V	Isolated fractures of the C1 transverse process	Immobilization for 6 weeks with rigid collar

TAL, transverse atlantal ligament.