COMPARISON OF 2 PROXIMAL OSTEOTOMIES FOR THE TREATMENT OF HALLUX-VALGUS

Moderate to severe deformities of hallux valgus can be corrected with combination procedures, such as a proximal crescentic metatarsal osteo tomy and a distal soft tissue procedure. Because crescentic osteotomy allows for motion in all planes, inadvertent metatarsal elevation can result in metatarsalgia. The crescentic shelf osteotomy (CSO) provides a plantar shelf, decreasing the complication of dorsiflexion fixation , Eighteen polyurethane foam specimens in three groups were prepared a nd tested to failure on a servohydraulic Instron testing machine. The mechanical characteristics of stiffness, deformation, ultimate failure load, and stored energy were compared between single-screw fixation c rescentic osteotomies and single- and dual-screw CSOs in molded polyur ethane foam metatarsal sawbones. In addition, 12 cadaver specimens wer e randomly divided, and a CSC or crescentic osteotomy was performed. P reosteotomy and postosteotomy intermetatarsal, dorsiflexion, and prona tion angles were compared from radiograph measurements. The results sh owed comparable mechanical characteristics among the groups, as measur ed by the area under the curve (P = 0.95), ultimate failure load (P = 0.35), deformation (P = 0.63), and stiffness (P = 0.21). Greater impro vements were seen in the CSO group compared with the crescentic osteot omy group in correction of the intermetatarsal angle (4.8 degrees comp ared with 3.2 degrees) and of the first metatarsal plantarflexion (2.3 degrees compared with 3.2 degrees of dorsiflexion). However, these di fferences were insignificant (P = 0.10 and P = 0.41) with the numbers available. Compared with the crescentic osteotomy, a CSO may possibly provide easier initial fixation but similar mechanical properties.