Late Abduction Deformity of the Midfoot Following the “Medial Double” (Diple) Procedure for Hindfoot Valgus Deformity

CATEGORY: Hindfoot INTRODUCTION/PURPOSE: There has been considerable interest in recent years in performing a combined talonavicular and subtalar arthrodesis instead of a standard triple arthrodesis for a rigid hindfoot deformity. The ”medial double” (diple) avoids fusing the calcaneocuboid joint with its lateral incision, common bone block graft and high rate of complications. Although the results of the “medial double” are generally satisfactory, there are no reports of late midfoot abduction deformity, although it was predicted by Evans in 1975. METHODS: A 79 year-old-male with long-standing skin psoriasis with joint involvement presented with severe bilateral flatfoot deformities. The left hindfoot was arthritic, deformed and painful. Despite a conservative course of orthotics and ankle braces, the pain persisted. Because there was a psoriatic plaque over the lateral side of the foot, it was decided to perform a ”medial double” arthrodesis with screw fixation, a plantarflexing 1st tarsometatarsal joint fusion for medial column stabilization, and a heel cord lengthening RESULTS: Skin and bony healing were uneventful. Over the subsequent three years a progressive abduction deformity developed through the naviculocuneiform joints and the unfused calcaneocuboid joint. The patient had only occasional pain in the midfoot and wore wide shoewear to accommodate the deformity. CONCLUSION: A late abduction deformity can develop through the midfoot in patients who have the ‘medial double” procedure for hindfoot valgus. The cuboid settles proximally against the short distal calcaneus, and the naviculocuneiform joints sublux laterally. In patients with hindfoot valgus with severe lateral column shortening secondary to calcaneocuboid joint remodeling, it may be better to perform an actual triple arthrodesis with a bone graft in the calcaneocuboid joint instead of a “medial double.” Alternatively, one could add a naviculocuneiform arthrodesis to the ”medial double” arthrodesis to prevent this complication.