[Malalignment of the first ray : Clinical and radiological diagnostics].

Clinical and radiological examination of the foot are mandatory before surgical correction of the forefoot. The clinical examination includes leg axis, position of the hind foot, deformity of the first ray as well as skin conditions, pulse status and possible sensitive deficits. A shortening of the gastrocnemius muscle can be identified using the Silfverskiöld test. Discomfort in the midfoot can indicate pathologies of the tarsometatarsal joint and the same applies for osteophyte infiltration around the Lisfranc joint line, whereby the second tarsometatarsal joint often shows more advanced degenerative arthritis than the first tarsometatarsal joint. Callosities under the second and third metatarsal heads correlate with a faulty load transmission of the first ray. A limitation of the range of movement of the first metatarsophalangeal joint is usually associated with degenerative arthritis in X‑ray imaging. Under weight bearing, X‑rays of the foot in two planes represent the standard imaging examination. In addition to the intermetatarsal angle, the hallux valgus angle and the interphalangeal angle as well as the width of the first metatarsal bone influence the therapy decision. The same applies to degenerative changes or an obvious instability of the first tarsometatarsal joint. In many cases, initial signs of degenerative arthritis can be found in the metatarsophalangeal joint and around the sesamoid bones, although these often do not correlate to clinical symptoms.