Response to: Confidence in the ATTUNE Knee is Driven by Real-World Scientific Evidence: Response to Bonutti et al. Article

In a letter to clinicians dated June 14, 2017 (“the DePuy Letter”),1 Dr. Daniel Funk (US Franchise Medical Director for DePuy Synthes) and Mr. Joshua Bridgens (EMEA Franchise Medical Director for DePuy Synthes) wrote a four-page commentary on the article published in the Journal of Knee Surgery using terms such as “inaccurate” and “misleading” and provided 19 references to support their letter.2–20 This is a response to this DePuy commentary. The article by Bonutti et al points to design issues in the DePuyATTUNE tibial baseplateDePuySyntheswhichmay lead to early failure of the tibial component (i.e., cement debonding at thetibial implantcement interface at short-term follow-up). It identifies 15 cases of catastrophic tibial component debondingwith tibial component pistoningoff thecementmantle and failure of cement fixation to the tibial implant. In these cases, the tibia could simplybe liftedoff the cementmantlemanually (►Figs. 1–3). The authors of this article identified several possible design deficiencies, which could contribute to early failure, and these appear to have been confirmed by DePuy’s recent launch of the ATTUNE Sþ tibia for their fixed bearing system.TheATTUNERP tibiamayalsohave issueswithcement fixation and we have identified severe backside polyethylene wear in this revision series (►Figs. 4 and 5).