MAUDE Adverse Event Report: STRYKER ORTHOPAEDICS-MAHWAH UNKNOWN TRIDENT SHELL; HIP IMPLANT

Catalog Number UNK_SHC

Device Problems Malposition of Device (2616); Positioning Problem (3009)

Patient Problems Injury (2348); Joint Dislocation (2374)

Event Date 01/03/2018

Event Type  Injury  

Manufacturer Narrative

An event regarding dislocation involving an unknown trident shell was reported.The event was confirmed.No implants were returned for investigation a review of the device history records could not be performed as lot code information was not provided.A complaint history review could not be performed as lot code information was not provided.Patient-related factors no info.Device-related factors: none.A medical review was conducted and concluded: the low cup inclination angle with medialized position make the system vulnerable to impingement between cup rim or acetabular bone on one side and neck of stem on the other side, especially in flexion and/or internal rotation.During the stance phase of the gait cycle or with extreme range of motion in the hip, high forces are transmitted across the hip joint and if under such conditions the neck of the stem hits the rim of the liner, significant strain may be applied to the poly articulation with significant risk on subluxation and/or dislocation.Cup position thus clearly represents a procedure-related factor present in this case to facilitate dislocation of the arthroplasty because the surgeon is responsible for optimal component positioning.The principal problem of this patient is cup malposition leading to dislocation which failed to be treated by closed reduction due to the occurrence of an intraprosthetic dislocation requiring open revision surgery about which no specific info has been provided.

Event Description

Patient experienced a dislocated right hip.He was reduced in the emergency department.He later [prior to discharge] explained to the surgeon that it did not feel right.Doctor operated on the affected right hip and discovered that the restoration adm insert had disassociated from the 28mm/ +8 v40 head.A review by a clinical consultant has identified an unknown trident shell as being malpositioned."the principal problem of this patient is cup malposition leading to dislocation".

Manufacturer Narrative

Corrected data: common device name, product code; an event regarding dislocation of an adm liner and a metal head was reported.Malposition of the unknown trident shell was confirmed by medical review.Method & results: -product evaluation and results: not performed as the device was not returned -medical records received and evaluation: a review of the medical information provided concluded the following: procedure-related factors: - cup malposition in low inclination and medialized position.- capsular laxity was still present relatively early post arthroplasty - use of a skirted head may reduce effective range of motion in an arthroplasty patient-related factors - no info.Device-related factors: - none.Diagnosis: - cup malposition in low inclination and medialized position and capsular laxity early post arthroplasty together with use of a skirted head have in concert contributed to instability causing a hip dislocation.The presence of an adm system caused an intraprosthetic type of dislocation that could only be reduced by open reduction.-product history review: could not be performed as the lot id was not provided.-complaint history review: could not be performed as the lot id was not provided.Conclusions: the medical review concluded: cup malposition in low inclination and medialized position and capsular laxity early post arthroplasty together with use of a skirted head have in concert contributed to instability causing a hip dislocation.The presence of an adm system caused an intraprosthetic type of dislocation that could only be reduced by open reduction.No further investigation for this event is possible at this time as no devices were returned to stryker orthopaedics.If devices or additional information become available to indicate further evaluation is warranted, this record will be reopened.

Event Description

Patient experienced a dislocated right hip.He was reduced in the emergency department.He later [prior to discharge] explained to the surgeon that it did not feel right.Doctor operated on the affected right hip and discovered that the restoration adm insert had disassociated from the 28mm/ +8 v40 head.A review by a clinical consultant has identified an unknown trident shell as being malpositioned."the principal problem of this patient is cup malposition leading to dislocation".

• Brand Name: UNKNOWN TRIDENT SHELL
• Type of Device: HIP IMPLANT
• Manufacturer (Section D): STRYKER ORTHOPAEDICS-MAHWAH; 325 corporate drive; mahwah NJ 07430
• MDR Report Key: 7235679
• MDR Text Key: 98835437
• Report Number: 0002249697-2018-00293
• Device Sequence Number: 1
• Product Code: MEH
• Combination Product (y/n): N
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional,other
• Type of Report: Initial,Followup
• Report Date: 03/06/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 02/02/2018
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Health Professional
• Device Catalogue Number: UNK_SHC
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: No
• Date Manufacturer Received: 02/07/2018
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Hospitalization; Required Intervention
• Patient Age: 81 YR
• Patient Weight: 135