The intermetatarsal angle is widely used to determine whether a basal or distal metatarsal osteotomy should be used to correct a hallux valgus deformity. We have noticed that the point of intersection of the long axes of the first and second metatarsals on standard pre-operative weight-bearing AP radiographs consistently predicts the type of osteotomy required.

A basal osteotomy is generally recommended if the inter-metatarsal angle is ≥14°, whereas a distal osteotomy is usually sufficient if the angle is less than 14°.

Sixty standardised pre-operative AP weight bearing in-patients undergoing hallux valgus correction were included in our study. The intermetatarsal angle was measured in a standard fashion. The point of intersection in the foot was recorded in terms of the distance from the talonavicular joint.

Using a Pearson’s Correlation coefficient, our study revealed that an intermetatarsal angle of 14° or more consistently intersected either within the talar head or distal to thetalonavicular joint. We propose that this as an accurate and simple method of pre-operatively determining the choice of metatarsal osteotomy.