A bhr head (74123144 14dw13448 sn (b)(4)) and bhr cup (74122150 14cw13346 sn (b)(4)) were received for investigation following hip revision surgery for a loose socket.No medical documents were received.The production records were reviewed for the returned devices.All the released devices involved met manufacturing specifications at the time of production.Visual inspection was carried out on the returned devices.Fine scratches were observed on the bearing surface of the bhr head.Fine scratches were observed on the bearing surface of the bhr cup.Wear analysis was performed to review linear wear on the bearing surface of the bhr head and bhr cup.The wear image for the bhr cup shows the wear patch at the edge of the cup.The wear image for the bhr head shows a wear patch on the bearing surface on the head.Maximum linear wear was 47.5¿m for the bhr head.Maximum linear wear was 49.6¿m for the bhr cup, for a combined head and cup maximum linear wear of 97.1¿m.Based on historic wear data, after 5.36 years in vivo, the measured combined linear wear is higher than the expected wear for a non-edge loaded smith and nephew large diameter metal-on-metal device.The position of wear on the acetabular cup shows that edge loading has occurred.Based on this investigation the root cause of the reported revision could not be determined conclusively.However, the position of the wear indicates that edge loading has occurred, which could explain the wear observed.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 at aurora uk and are available if requested.Additional information: brand name, device manufacture date.
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