MAUDE Adverse Event Report: EXACTECH, INC. EQUINOXE REVERSE COMPRESSION SCREW

Catalog Number 320-15-38

Device Problems Device Slipped (1584); Naturally Worn (2988); Loosening of Implant Not Related to Bone-Ingrowth (4002)

Patient Problems Joint Disorder (2373); No Code Available (3191)

Event Date 04/18/2018

Event Type  Injury  

Manufacturer Narrative

Pending evaluation.

Event Description

Revision due to loosening and suspected poly wear.

Manufacturer Narrative

Visual evaluation condition/findings (conducted with a 7x or 10x optical) the scratches the returned reverse humeral adapter tray appears consistent with coming into contact with sharp metal instruments during the implantation and removal of the device.The scratches on the humeral stem appear consistent with articulating against boney impingement.The glenoid plate was returned with residual bone.This is an expected function of the plate.The scratches on the surface of the returned glenoid plate appear consistent with articulating against a the threads of the compression screws seems to be unremarkable and consistent with being implanted.Disassociated glenosphere and using a metal instrument to remove the glenoid plate.The deformation on the compression screw appears consistent with using a hex driver to insert the screw in the original surgery.The deformations suggest that the screw was tightened substantially, which stripped the hex head and may have caused cross-threading.The threads of the torque defining screw seem to be unremarkable and consistent with being successfully implanted.The sheared surface of the reverse torque defining screw appears consistent with normal use.When the reverse torque defining screw is implanted using a reverse fixed angle torque screw driver, the top part of the screw is intended to break off.The area of burnishing at the neck and head of the locking screw appears consistent with rubbing against a hard, metal surface such as the interior of the apical hole of the glenosphere during insertion and possibly after disassociation.The deformation on the locking screw appears consistent with using a hex driver to insert the screw in the original surgery.The deformations suggest that the screw was tightened substantially, which stripped the hex head and may have caused cross-threading.The excessive wear of the humeral liner appear to be consistent with the dislocation of the glenosphere.Once dislocated, the glenosphere may have been articulating against the edge of the liner rather than centered.Since the glenosphere was free, the deformation may have come from boney impingement as well.The deformed locking button on the humeral liner was most likely deformed due to the humeral liner disassociating from the tray, allowing it to articulate.It is unclear if the liner was fully assembled to the tray at the time of the initial surgery.The scratches on the surface of the glenosphere appear consistent with coming in contact with the liner while implanted.Once worn, the surface of the humeral liner becomes rough and is capable of scratching the surface of the glenosphere.The frequency of occurrence ranking scale is very low; therefore, this does not appear to be design-related.The company is not aware of receiving any other complaint reports involving parts from the complaint manufacturing lots.Manufacturing data for the humeral liner could not be reviewed because the manufacturing lot/serial information was not provided.A review of the device history record showed that the humeral stem and glenoid plate were accepted with conformance to the device requirements.Therefore, this does not appear to be manufacturing-related.Properly functioning implants depend on their appropriate fixation to the bone; fixation is usually achieved by cementing the implant onto the bone.Some surgeons prefer to use biologic (non-cemented) fixation.Although implants are firmly fixed at the initial surgery, they may become loose over time.The loosening and wear of the humeral liner reported was likely the result of not cementing at the time of initial surgery.Additionally, these implants were implanted for over 5 years.Wear of the humeral liner is expected over time.The patient is reported to have multiple (un-named) co-morbidities, the fact that the patient is obese and young suggest added biomechanical stressors to the natural joint and the shoulder implant.It is noted in a review of the labeling -device specific risks include: fracture, migration, loosening, subluxation, or dislocation of the prosthesis or any of its components, any of which may require a second surgical intervention or revision.It is also noted that excessive wear of the implant components secondary to impingement of components or damage of articular surfaces.It is a known complication that a patient's age, weight, or activity level would cause the surgeon to expect early failure of the system.General surgical risks include, superficial or deep infection and total joint surgical risk include soft tissue damage which may lead to a second surgical intervention or revision.Also, as part of the pre-operative assessment, the surgeon must ensure that no biological, biomechanical, or other factors exist that might adversely affect the surgery and/or the postoperative period.All patients should be instructed on the limitations of the prosthesis and the possibility of subsequent surgery.The patient should be cautioned to monitor activities and protect the replaced joint from unreasonable stresses and follow the written instructions of the physician with respect to follow-up care and treatment.This device is used for treatment not diagnosis.Information about the patient and event were requested, there was no new information available.

Event Description

It was reported that a patient experienced a right shoulder revision, due to loosening.There is no initial implant date available.The patient is stated to have "a lot of co-morbidities".The surgeon "suspects poly wear - and some fairly severe wear on the inferior aspect of the liner." the explanted parts were: 42mm glenosphere, 15mm humeral stem, 42mm humeral liner, 0+ humeral tray.The patient was reported to be stable when leaving the operating room.There is no additional information available on the patient or event.This is one of fifteen products involved with the reported event and the associated manufacturer report numbers are 1038671-2018-00320, 1038671-2018-00321, 1038671-2018-00322, 1038671-2018-00323, 1038671-2018-00324, 1038671-2018-00325, 1038671-2018-00327, 1038671-2018-00328, 1038671-2018-00329, 1038671-2018-00330, 1038671-2018-003331, 1038671-2018-00332, 1038671-2018-00333 and 1038671-2018-00347.

• Brand Name: EQUINOXE REVERSE COMPRESSION SCREW
• Type of Device: EQUINOXE REVERSE COMPRESSION SCREW
• Manufacturer (Section D): EXACTECH, INC.; 2320 nw 66th court; gainesville FL 32653
• MDR Report Key: 7468904
• MDR Text Key: 106756972
• Report Number: 1038671-2018-00326
• Device Sequence Number: 1
• Product Code: KWT
• Combination Product (y/n): N
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,health
• Type of Report: Initial,Followup
• Report Date: 06/23/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 04/27/2018
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Physician
• Device Catalogue Number: 320-15-38
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 04/20/2018
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 06/20/2019
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Required Intervention
• Patient Age: 61 YR
• Patient Weight: 112