Austin bunionectomy: postoperative MRI evaluation for avascular necrosis.

The authors used magnetic resonance imaging (MRI) to evaluate the formation rate of avascular necrosis following performance of 20 modified Austin bunionectomies. Five modified McBride bunionectomies without first metatarsal osteotomy were also performed as an MRI control. Results showed an avascular necrosis formation rate of 50%. The majority of the avascular necrosis areas were found dorsally within the cancellous bone substance of the first metatarsal head. These lesions, in all cases, did not cause any patient disability or result in any decline in the degree of patient satisfaction. The MRI positive avascular necrosis evaluations do suggest potential problem areas with the surgical technique that may be eliminated through further modification of the classic Austin bunionectomy procedure.