Long Z-osteotomy: a review and new modification to correct troughing.

The long Z-osteotomy (scarf) has proven to be an effective procedure for correction of the metatarsus primus varus component of the hallux abducto valgus deformity. An historical review and technical considerations of the procedure are described. Although technically demanding, it offers the advantages of superior strength with internal fixation, early range of motion, and early weightbearing. An uncommon but challenging intraoperative complication of the procedure is troughing (channeling). The author describes a technique that involves transfer of the adductor hallucis tendon through the horizontal aspect of the osteotomy when troughing is encountered. The benefits and potential complications are discussed. Although it occurs infrequently, this new modification has the potential to salvage a potentially debilitating complication.