A bhr modular head 50mm (details not visually confirmed 74222150, 08mw20898) and modular sleeve +4mm (details not visually confirmed 74222300, 08fw17520) were received for investigation following left hip revision surgery due to elevated serum metal ion levels.During the revision the bhr cup and synergy femoral stem remain implanted.The production records were reviewed for the known devices reportedly involved in this incident.Review of manufacturing records did not reveal any waivers, concessions, manufacturing or material abnormalities that could have contributed to this issue.Visual inspection was carried out on the returned devices.Fine scratches could be observed on the bearing surface, damage was noted on the rim of the head and discolouration on the rim at the taper interface.The sleeve could not be removed from the head without using excessive force.Surface texture change and discolouration were observed on the internal sleeve taper.Wear analysis was performed to review linear wear on the bearing surface of the bhr modular head and modular sleeve.The wear images identified a wear patch on the bearing surface of the head.Maximum linear wear for the modular head was 9.2m.Taper analysis for the linear wear of the sleeve measure the maximum depth of material loss measured at 47.8 m.The maximum linear wear on the bearing surface of the head was 9.2 m.Based on historic wear data, after approximately 10 years in vivo, the measured linear wear for this head is in line with the expected wear for a head in a non-edge loaded smith and nephew large diameter metal-on-metal device.Material loss was measure on the internal taper of the sleeve.The available medical documents were reviewed.The revision of the left hip was performed after approximately 10 years due to elevated serum metal ion levels.The patient was asymptomatic and has a contralateral hip replacement (type unknown).The metal femoral head was replaced by a dual mobility / oxinium ball head combination, indicating that the cup and stem remained in-vivo.It was reported, that at surgery the joint appeared infected and a pseudotumor was excised.An image of a solid tissue mass of approximately 15 cm to 15 cm (largest diameters) was provided, resembling an excised pseudotumor.The provided x-rays dated approximately 3 months before the revision no obvious findings that could explain the reported elevated blood metal ions.No additional information such as surgical report, histopathological analysis or reports of the blood metal ions concentrations were provided.There was wear on the articulation surface and material loss was measured on the internal taper of the sleeve.A relation between the material loss and wear and the reported elevated blood metal ions cannot be excluded.The nature of the excised tissue mass (pseudotumor) cannot be further assessed, without additional information.Based on this investigation the root cause of the reported revision could not be determined conclusively.If additional information become available in the future, this case will be reopened.No preventative or corrective action has been initiated as a result of this investigation.The devices will be retained.
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