A Prospective, Randomized, Single-blind, Controlled, Multi-center Study to Assess the Safety and Performance of MagnetOsTM Compared to Autogenous Bone Graft in Patients Undergoing Hindfoot or Ankle Fusions.

This is a phase IV post-marketing study for MagnetOs Putty and MagnetOs Easypack Putty. MagnetOs is a synthetic bone graft extender product that is routinely used by surgeon as treatment for hindfoot and ankle disorders. In this study, MagnetOs Putty and MagnetOs Easypack Putty will be use according to the latest Instructions For Use, standalone in the foot and ankle.

In this study, following a screening period of a maximum of 45 days, approximately 126 patients will receive either MagnetOs Putty/Easypack Putty or autograft in conjunction with rigid hardware (arthrodesis) to treat hindfoot and ankle disorders. They will be randomized (1:1) into one of two treatment groups: standard rigid fixation with MagnetOs Putty/Easypack Putty or local autograft from the calcaneus, distal tibia, or proximal tibia. They will be followed up at discharge at weeks 2, 6, 12, 24 and 52 post-surgery. The primary endpoint will be analyzed at 24 weeks post-op using CT-scan, and patients will continue follow-up for safety and efficacy for one year post operatively. In this study, MagnetOs will be applied according to the IFU (Putty) approved in the US, Europe, Middle- East and Australia and Easypack Putty (approved in the US). The surgical procedures studied in this clinical trial will include rigid hardware fixation and supplemental bone graft/substitute in the following procedures: ankle fusion (tibiotalar), subtalar fusion (talocalcaneal), calcaneocuboid fusion, talonavicular fusion, OR double fusion (any combination of any two of the following: subtalar, talonavicular and calcaneocuboid joints. These procedures will be left to the investigator's discretion. Radiographs images will be taken at screening, weeks 6, 12, 24 and 52; CT-scans will be taken at weeks 24 and 52 post-op If the patient has a secondary surgical intervention (procedure that adjusts or in any way modifies or removes part of the original implant configuration) at any time after the 6 month visit, the next CT scan will not be necessary. Starting at week 12, all XR images will be weight bearing.