OsteoSinter® EVANS and COTTON — Porous titanium wedge implants

OsteoSinter® EVANS and COTTON are implantable porous titanium wedges, developed by AMES Medical for the correction of foot deformities — particularly adult-acquired flatfoot (progressive collapsing foot deformity). The wedges are used as an interposition element in opening-wedge osteotomies, restoring and maintaining correction without the need for a bone graft (autograft or allograft).

The OsteoSinter® material (commercially pure titanium, CPTi, manufactured by powder metallurgy and patented — EU2476065B1) has an interconnected, bio-mimetic porosity that reproduces the structure of trabecular bone. This porosity induces osseointegration of the adjacent bone, and its mechanical behavior, similar to that of trabecular bone, has been validated by the Institute of Biomechanics of Valencia (IBV). The high primary fixation eliminates the need for any supplementary fixation (no plates and/or screws).

The EVANS range comprises 9 sizes (footprints of 18×18, 20×20, and 22×22 mm, in heights of 8, 10, and 12 mm) for lateral column lengthening (Evans osteotomy / calcaneal Z osteotomy). The COTTON range comprises 6 sizes (lengths of 15 and 20 mm, in heights of 4.5, 5.5, and 6.5 mm) for the opening-wedge osteotomy of the medial cuneiform (Cotton osteotomy). Implantation is performed with a single-use instrument set (sizers, grasping forceps, and impactor), reducing operative time to 20–30 minutes, with no in-situ shaping. Since its commercial launch in 2021, more than 2,000 procedures have been performed in over 20 countries.

• Correction of adult-acquired flatfoot deformity (progressive collapsing foot deformity).
• Opening-wedge osteotomies of the foot bones, including additive osteotomies for hallux valgus.
• Cotton osteotomy — opening of the medial cuneiform (correction of forefoot supination).
• Lateral column lengthening — Evans osteotomy or calcaneal Z osteotomy.
• Metatarsal/cuneiform (fusion) arthrodeses.