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

Catalog Number 320-15-30

Device Problems Break (1069); Fracture (1260)

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

Event Date 02/03/2018

Event Type  Injury  

Manufacturer Narrative

Pending evaluation.

Event Description

Revision due to screw breakage.

Manufacturer Narrative

Visual evaluation condition/findings (conducted with a 7x or 10x optical) 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.Scratches on the inside surface of the glenosphere appear consistent with articulating against the glenoid plate following the disassociation.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 surface of the glenoid plate were likely the result of articulating against the broken glenosphere locking screw and the underside of the glenosphere after the glenosphere disassociated from the reverse glenoid plate.The damaged threads at the glenosphere locking screw location appear consistent with using a hard metal instrument, such as forceps, to aid in removing the device during revision.The damaged edges of the humeral liner appear consistent with coming into contact with sharp, metal instruments during the implantation and removal of the device.The wear on the articulating surface of the humeral liner appears 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 threads of the compression screws seem to be unremarkable and consistent with being implanted.The damaged threads on the 34mm compression screw appear to be consistent with cross-threading the screw off-axis into the glenoid plate.The threads of the torque defining screw seem to be unremarkable and consistent with being successfully implanted.The breakage of the locking screw appears consistent with a brittle fracture associated with extreme loads acting perpendicular to the axis of the screw.The loads were likely a result of not fully seating the glenosphere.The system is intended to transmit forces through the glenosphere to the glenoid plate.When not fully seated, it is possible for the forces to be transmitted through the glenosphere and the locking screw, creating forces on the locking screw that cannot be supported.The area of burnishing at the neck of the locking screw appears consistent with rubbing against a hard, metal surface such as the interior surface of the apical hole of the glenosphere during insertion and possibly after disassociation.All other aspects of the device appear unremarkable.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 device manufacturing lots.Manufacturing data for the humeral liner and two of the compression screws could not be reviewed because the manufacturing lot/serial information was not provided.A review of the device history record showed that the glenosphere locking screw was accepted with conformance to the device requirements.Therefore, this does not appear to be manufacturing-related.The screw breakage reported was likely the result of the glenosphere not being fully seated at the time of the initial surgery.The system was intended to transmit forces through the glenosphere to the glenoid plate.When not fully seated, it is possible for the forces to be transmitted thought the glenosphere and the locking screw, creating forces on the locking screw that cannot be supported.There is not any patient medical history provided to do a clinical risk assessment.In a review of labeling it is noted that only qualified surgeons are to use these products: who are fully knowledgeable about all aspects of the surgical techniques and use these implants, have full knowledge about the system compatibility's, and must be fully trained to properly use the system instrumentation.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.All patients should be instructed on the limitations of the prosthesis, 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.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.Revisions or surgical interventions are a known complication found in joint replacements.Surgical tip from operative technique if you hear the glenosphere locking screw "squeaking" prior to the screw head being recessed in the glenosphere apical hole-stop.The glenosphere is not seated on the baseplate correctly.Run an instrument along the backside of the glenosphere to feel for the plate.You should not feel any of the plate if the glenosphere is seated properly.You can also visually assess this anteriorly.This device is used for treatment not diagnosis.Serial numbers are unknown the purchase order number was submitted for the serial number.

Event Description

It was reported that a patient experienced a right shoulder revision due to a broken glenosphere screw.The patient heard a pop in her shoulder; an x-ray showed the glenosphere screw lying next to the tray (emailed image provided).Where the screw snapped, about 5mm remained in the baseplate, the surgeon used a diamond bit to remove the remaining screw tip.Then the bony through growth was removed with a 2.5mm drill bit, and finally a removal tool was attached to the baseplate center and a slap hammer was used to remove it.The surgeon re-implanted the same baseplate (8-degree post.Aug), drilled new holes, put on the same size glenosphere (38mm) used a 5mm tray, and 0mm 38 liner.The stem stayed in place.There is no additional information.This is one of fourteen products involved with the reported event and the associated manufacturer report numbers are 1038671-2018-00089, 1038671-2018-00090, 1038671-2018-00091, 1038671-2018-00096, 1038671-2018-00097, 1038671-2018-00099, 1038671-2018-00100, 1038671-2018-00101, 1038671-2018-00102, 1038671-2018-00103, 1038671-2018-00104, 1038671-2018-00105 and 1038671-2018-00106.

• 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: 7267505
• MDR Text Key: 99945911
• Report Number: 1038671-2018-00098
• 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: health professional
• Type of Report: Initial,Followup
• Report Date: 06/26/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 02/13/2018
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Physician
• Device Catalogue Number: 320-15-30
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 02/13/2018
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 06/19/2019
• Patient Sequence Number: 1
• Patient Outcome(s): Required Intervention
• Patient Age: 76 YR
• Patient Weight: 57