It was reported that a revision was performed due to unspecified reasons.It was reported that when attaching the chisel blade to remove a single-condylar prosthesis g-ii from 1st implantation on (b)(6) of 2015, the femoral component immediately becomes torn and breaks off directly at the proximal shield.Surgeon states that there were a distinctive pe wear due to the varicose joint axis of an implanted medial g-ii single-condylar prosthesis.The lateral femoral condyle also showed considerable cystic defects due to metal and pe abrasion - so that after explantation of the medial slide a legion revision prosthesis with bar extension tibially and femorally, posterior lat.Wedge 5 mm femoral and medial tibial wedge 5 mm and cc inlay 11 mm were implanted.Also, was reported that the femoral and tibial components themselves were well cemented and not loosened.
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The associated complaint devices were returned and evaluated.A lab analysis conducted during this investigation noted the returned devices were examined visually and using optical microscopy.The returned femoral implant was also imaged using a sem.The femoral device was reported to have fractured off during the explant process.The fracture site was located anterior with respect to the post.Bone cement was observed on about 50% of the femoral cement pocket.A clear striation pattern in the part indicates that the femoral component likely experienced fatigue loading while implanted.Signs of abrasion, burnishing and material deformation can be seen on the articulating surface of the insert.One side of the insert showed significantly more wear and deformation than the other.Scratches were observed on the baseplate¿s bone cement interface surface.Based on this analysis, the material deformation on the insert, and subsequent femoral implant fracture during explantation, are likely caused in-part due to fatigue loading.No material or manufacturing deviations were found during the investigation.The review of complaint history on the listed parts revealed no prior complaints for the listed batch with the same failure mode.A clinical evaluation noted that without the post-primary images for comparison, the revision operative note, or lab results the reported ¿cystic defects due to metal and pe abrasion¿ cannot be confirmed and the root cause of the reported ¿pe wear¿ could not be concluded.However, 3rd body debris could have been a possible contributing factor to the reported issue and reported subsequent cystic defects.The patient impact beyond the reported revision and an expected brief post-op rehab phase cannot be determined.No further investigation is warranted for this complaint; however we will continue to monitor for future complaints and investigate as necessary.Should additional information be received, the complaint will be reopened.
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