MAUDE Adverse Event Report: SMITH & NEPHEW ORTHOPAEDICS AG POLARSTEM STEM LAT.TI/HA 1 NON-CEM; PROSTHESIS, HIP, SEMI-CONSTRAINED, METAL/POLYMER, UNCEMENTED

Model Number 75100474

Device Problem Fracture (1260)

Patient Problem Failure of Implant (1924)

Event Date 11/19/2020

Event Type  Injury  

Manufacturer Narrative

Complaint reference: case-(b)(4).

Event Description

It was reported that a revision surgery of polarstem stem lat.Ti/ha 1 non-cem was performed due to breakage of the stem.Stem, head, liner and cup were removed.

Manufacturer Narrative

H3, h6: it was reported that a revision surgery of polarstem stem lat.Ti/ha 1 non-cem was performed due to breakage of the stem, which intent use is in treatment.The device was returned for investigation and the fracture surfaces were analyzed.About three quarter of the fracture surface show fatigue striations, indicating that the crack propagated by fatigue and significant torsional and shear force components have likely contributed to failure.But no pores or inclusions, which could have initiated or enhanced crack growth, could be observed on the fracture surface.The provided x-rays show the broken stem along with radiolucency around the proximal portion, which is consistent with stress shielding and micromotion.This could also indicate a stress fatigue break of the stem.A thorough product history review was performed as well.No deviations found in the corresponding batch record or material certificate.For the batch number in scope no other complaint can be found.For the specific article number no similar complaint can be found.An implant fracture is a rare but known risk of a total hip endoprosthetic and mentioned in our current risk manage file and rated as low as well in our current instruction for use for hip implants.With the information provided the clinical root cause of the stem breakage cannot be confirmed.However, stress fatigue and significant torsional and shear force of the components as a result of poor bone support from stress shielding is the likely factor that lead to the micromotion and fatigue failure.It cannot be concluded that the reported stem breakage was associated with a mal-performance of the implant.The root cause can not be established.Smith + nephew will monitor this device for similar issues.The returned article will be retained.

• Brand Name: POLARSTEM STEM LAT.TI/HA 1 NON-CEM
• Type of Device: PROSTHESIS, HIP, SEMI-CONSTRAINED, METAL/POLYMER, UNCEMENTED
• Manufacturer (Section D): SMITH & NEPHEW ORTHOPAEDICS AG; schachenallee 29; aarau CH-50 00; SZ CH-5000
• MDR Report Key: 11016918
• MDR Text Key: 221736763
• Report Number: 9613369-2020-00260
• Device Sequence Number: 1
• Product Code: LWJ
• UDI-Device Identifier: 07611996118650
• UDI-Public: 07611996118650
• Combination Product (y/n): N
• PMA/PMN Number: K130728
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,foreig
• Type of Report: Initial,Followup
• Report Date: 05/09/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Health Professional
• Device Model Number: 75100474
• Device Catalogue Number: 75100474
• Device Lot Number: B1816896
• Was Device Available for Evaluation?: Yes
• Initial Date Manufacturer Received: 11/19/2020
• Initial Date FDA Received: 12/16/2020
• Supplement Dates Manufacturer Received: 04/26/2021
• Supplement Dates FDA Received: 05/09/2021
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Treatment: HEAD 71343608, LOT 19CM12784; LINER 71335756, LOT19DM05070; SHELL 71335556, LOT19CW22471; HEAD 71343608, LOT 19CM12784; LINER 71335756, LOT19DM05070; SHELL 71335556, LOT19CW22471
• Patient Outcome(s): Hospitalization; Required Intervention
• Patient Weight: 114