Role of metatarsus primus elevatus in the pathogenesis of hallux rigidus

Metatarsus primus elevatus has been suggested as a primary causative factor in the pathogenesis of hallux rigidus. The purpose of this investigation w as to define the role of elevation of the first ray in the pathogenesis of hallux rigidus by comparing patients with known hallux rigidus with a contr ol population. We reviewed 264 lateral weightbearing radiographs from 81 pa tients with hallux rigidus, 50 asymptomatic volunteers, and 64 patients dia gnosed with isolated Morton's neuroma. Results revealed that the mean value s for elevation of the first ray in patients with mild or moderate hallux r igidus were nearly identical to those in the control group. Patients with a dvanced radiographic hallux rigidus had a slightly higher mean value for me tatarsus primus elevatus. An average of nearly 8 mm of metatarsus primus el evatus is a normal finding in patients with hallux rigidus as well as in no rmal subjects. This investigation did not address the clinical outcome or b iomechanical effects of a plantarflexion osteotomy of the first ray. Howeve r, on the basis of the finding that first ray elevation is normal, it seems unlikely that a plantarflexion osteotomy would have a role in the treatmen t of hallux rigidus.