Affiliation:
1. University of Southern California Department of Orthopaedic Surgery, LAC/USC Medical Center, Los Angeles, California 90033
2. Rancho Los Amigos Medical Center, Downey, California 90242
Abstract
Five different intertarsal arthrodeses were simulated in 15 fresh cadaver feet/ankles utilizing external fixation. Pin placement was verified radiographically. Range of motion measurements were performed before pin placement, after pin placement, and after simulated arthrodesis. The deficit in foot motion created by selected limited intertarsal fusions was then measured. The prearthrodesis range of motion measurements were found to be dorsiflexion (DF), 27°; plantarflexion (PF), 57°; total inversion (INVT), 29°; eversion total (EVT), 22°; hindfoot varus (VRH), 16°; hindfoot valgus (VLH), 12°. The deficits in motion after arthrodesis were as follows. Ankle (tibiotalar): DF, 50.7%; PF, 70.3%; INVT, 8.7%; EVT, 9.4%; VRH, 34.6%; VLH, 27.8%. Hindfoot arthrodesis (Tibiotalar calcaneal): DF, 53%; PF, 71.3%; INVT, 49.5%; EVT, 47.6%, VRH, 100%; VLH, 100%. Pantalar (Tibotalar calcanea cuboid navicular): DF, 62.8%; PF, 82.2%; INVT, 71.7%; EVT, 67.4%; VRH, 100%; VLH, 100%. Triple (Talocalcaneal cuboid navicular): DF, 12.5%; PF, 15.5%; INVT, 50%; EVT, 51.4%; VRH, 60.5%; VLH, 60.5%. Total tarsal arthrodesis: DF, 78.5%; PF, 90.2%, INVT, 87.5%; EVT, 83.6%; VRH, 100%; VLH, 100%.