The value of radiographic parameters in the surgical treatment of hallux rigidus.

The purpose of this study was to determine if metatarsal protrusion or the length of the first and second rays were associated with the incidence of hallux rigidus. For this retrospective study, anteroposterior radiographs from 51 patients diagnosed with hallux rigidus and 51 patients without evidence of hallux rigidus were selected for review as a control group. Radiographs were randomly assigned to one of two raters who determined the metatarsal protrusion distance, first metatarsal length, second metatarsal length, length of the proximal phalanx of the hallux, length of the proximal phalanx of the second toe, and overall hallux length. A statistical comparison of these radiographic measurements showed only first metatarsal length to significantly differ (P = .05) between the two groups (65.4 +/- 5.3 mm and 67.7 +/- 5.9 mm for the hallux rigidus and control groups, respectively). The findings of this study suggest the need to revisit the role that metatarsal protrusion distance and first metatarsal length play in the etiology of hallux rigidus. In addition the need to surgically correct a long first metatarsal should be further evaluated.