Current review of trapeziometacarpal osteoarthritis (rhizarthrosis)

Table 1 Main ligaments of the trapeziometacarpal joint

Ligament		Description of the function
Dorsoradial (Figure 1)		Shortest and thickest ligament (Recently possible) Primary stabilizer against dorsal translation of the joint Opposes anterior oblique ligaments Basis for Eaton-Littler procedure
Anterior oblique (Figure 1)	Superficial	Stabilization against volar joint subluxation
	Deep	Known as beak ligament Act as a pivot point Primary joint stabilizer against dorsal translation
Posterior oblique		Stabilization of rotation
Intermetacarpal		Stabilization during radiovolar translation Stabilization of the thumb against collapse especially after trapeziectomy
Ulnar collateral		Helps to stabilization against volar joint subluxation

Table 2 Eaton-Littler classification of rhizarthrosis

Stage	Definition
I	Normal articular surface
	Possible widening of TMC joint indicating synovitis
II	Joint space narrowing
	Oteophytes < 2 mm
	Normal ST joint
III	Severe TMC destruction with subchondral sclerosis
	Osteophytes > 2 mm and presence of loose bodies
	Normal ST joint
IV	TMC and ST joints are both affected

TMC: Trapeziometacarpal; ST: Scaphotrapezial.