first metatarsophalangeal angle

The first metatarsophalangeal angle, also known as hallux valgus angle (HVA) or hallux abductus angle, is a measurement used to assess the presence and severity of the alignment of the first metatarsophalangeal joint on a weight-bearing dorsoplantar radiograph of the foot.

Measurement

The angle between the axis of the metatarsal bone and the proximal phalanx of the great toe is measured . The axis of both bones is defined either by bisection of head and base of both bones also referred to as center base/center head method or by bisecting the metatarsal shaft at two different points apart from each other of the diaphysis also referred to as shaft bisection .

Interpretation

An angle of > 15° indicates hallux valgus. A common grading scheme of hallux valgus in consideration of the first metatarsophalangeal angle is :

• normal: <15°
• mild: 15-20°
• moderate: 20-40°
• severe: >40°

However, for proper radiographic evaluation of the hallux valgus not only the first metatarsophalangeal angle but also the first intermetatarsal angle (IMA) should be included in the assessment.

See also

• hallux valgus
• intermetatarsal angle

Siehe auch:

• Hallux valgus
• erster intermetatarsaler Winkel 9 Grad
• vierter intermetatarsaler Winkel 8 Grad