Hallux disorder and metatarsal alignment.

The results of surgical procedures to correct hallux valgus have thus far been unpredictable. Hitherto the problem has been approached on the horizontal plane (i.e., from the dorsoplantar point of view), but the author has devised a new apparatus for measuring and recording the weight-bearing frontal alignment (WFA). Abnormal positions of the metatarsal heads, observed from the front, may cause pain in the forefoot, and hallux valgus may contribute to the problem. Analysis of the WFA before a surgical operation enables the surgeon to select the proper procedure for each foot and simultaneously to correct the defects in the horizontal and frontal planes. WFA analysis also enables the surgeon to avoid grave errors in choosing a surgical procedure. After hallux rigidus surgery, the forefoot tends to be more pronated than before and although painless, is predisposed to metatarsalgia. if the WFA is known, this can be avoided.