POTENTIAL FOR RECURRENCE OF HALLUX-VALGUS AFTER A MODIFIED HOHMANN OSTEOTOMY - A BIOMECHANICAL ANALYSIS

On the basis of a biomechanical model the present study investigates w hether a foot-widening effect, which may result in recurrence of bunio ns, can be demonstrated in operated patients. Therefore, the medial de viation of the first metatarsal head as a result of flexion forces on the hallux was measured in eight patients with clinical idiopathic hal lux valgus, who underwent a modified Hohmann osteotomy, and in eight ' 'normal'' persons. We found that (1) before osteotomy, all forefeet br oadened while pressing the big toe downward, and (2) after surgery, wi dening of the forefeet on average had significantly diminished, but st ill existed, which might explain the development of recurrences. (3) A fter surgery, the patients showed a slight, but statistically nonsigni ficant, decrease (from 37 N to 25 N) of the isometrically determined a verage maximal applicable flexion force. These abnormal hallux loads m ay cause, or result from, a deviation in gait pattern.