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Misonix received medwatch reference uf/importer report# (b)(4) on (b)(6) 2017 for a malfunction of mxb-20, lot# unknown, reporting "during a lateral transthoracic retro-pleural corpectomy with removal of herniated disc, the surgeon was using the bone scalpel and the tip of the blade broke off.An x-ray was performed to assure that the tip was not in the surgical wound.The x-ray was reported as negative by the radiologist.It is believed that the tip was suctioned into the suction canister.There was no harm to the patient." during (b)(6) 2017.Facility/user identification was disclosed as (b)(6) hospital and medical center, (b)(6).Reporter indicated as a health professional.Unable to verify the device was used consistent with the bone scalpel ultrasonic surgical system ifu recommendations.No report of the specific user was provided.Unable to verify that in service training was provided prior to use.No materials were returned for evaluation.Dhr review: an investigation cannot be performed based on reported device due to missing/unknown lot#.It is noted that mxb-20 is a sterile kit containing multiple component parts.The tip contained in the mxb-20 sterile kit is e4003abc20 blade - 20mm.Review of incoming inspection records for (b)(6) 2016 through (b)(6) 2017 for the e4003abc20 indicate that the manufacturer's lots met acceptance criteria.Misonix has sold (b)(4), mxb-20 from (b)(6) 2016 to (b)(6) 2017.Trend analysis: two (2) bonescalpel, 20mm, blunt, mxb 20 were returned to misonix from (b)(6) 2016 through (b)(6) 2017 where the service/engineering evaluation found a broken blade problem.Review of the specifics surrounding the details does not involve any other reports of malfunction.The return rate for this problem during the time period indicated above is (b)(4).Engineering evaluation: no material was returned.An engineering evaluation could not be performed.The predominant failure mode for ultrasonic bonescalpel, 20mm, blunt, blades that break during use is a partial or complete fracture.They typically do not shatter or create multiple unretrievable fragments that would difficult to locate or remove.The medwatch reported that the bonescalpel, 20mm, blunt, blade tip broke off during use.Because the surgical procedure is performed under surgeon's direct visualization and enhanced by loupe fitted eyeglasses or a microscope, the instrument failure can be promptly identified.Furthermore, the system is design to emit "mechanical limit" alarms when the tips fracture, further communicating to the user that something abnormal has occurred.When the tip factures, triggering the "mechanical limit" alarm, the device stops energizing the handpiece to which the tip is attached.The broken pieces can be easily visually identified, in some cases aided by the use of enhanced visualization by routine loupe fitted eyeglasses or microscopes and removed from the surgical field.Surgical suites typically have access to x ray equipment and would be able to quickly identify and locate any fragments not found by direct or enhanced visualization by using such equipment.The fractured piece can therefore be found and extracted quickly and easily without significant delay in the surgical procedure.The tips are shipped as sterile components in multiple packages; therefore the tip can replaced with a new one without significant delay in the surgical procedure.In the event that the bonescalpel couldn't be used to complete the procedure surgical suites have access to alternative technologies that can be used to complete the surgical procedure without significant delay in treatment.The product ifu (bcm-um, revision p) contains the following warning(s): caution 7.7: the system check should always be done in advance of preparing patient for surgery to minimize risk to patient in case of system malfunction.Warning 1.2: the bonescalpel system is intended to be used in various types of invasive, surgical procedures.There may be indirect danger to the patient should the device fail during the procedure.It is recommended that the facility follows its back-up equipment protocols.Warning 4.4 breakage of ultrasonic tips will result in sharp edges that can be harmful to soft tissue even without activation of ultrasound.Tips can bend or deform before they actually break.Tips showing signs of deformation or cracking should be replaced immediately since tip breakage is otherwise imminent.Do not bend or twist the ultrasonic tips since it reduces the structural integrity and can result in tip breakage during use.Dispose of deformed or broken tips immediately in a sharps container.Warning 4.3 ultrasonic tips can break under excessive use in extreme conditions, e.G.When cutting for extended duration in tight cavities with limited lateral motion.The tip could break into two or more fragments with the main fragment remaining attached to the handpiece.All fragments must be retrieved immediately from the surgical site.The fragments should be checked to ensure that no further pieces are missing.It is possible that a fragment is propelled outside of the surgical cavity.Diagnostic imaging, such as x-ray, must be used if a fragment cannot be found to confirm that the broken piece is outside of the surgical cavity.In addition, during surgery, other metal medical devices are used.Contact of the ultrasonic tip with other metal devices during surgery can damage the ultrasonic tip and cause fracture.The product ifu contains the following note: note 4.3 contact of the ultrasonic tip or exposed extension with metal, surgical instruments or other objects during ultrasound use must be avoided.Such contact can damage the ultrasonic components very easily and may result in compromised performance, including failure.Discard any extensions or tips that show signs of damages like gouges, nicks or fractures.External aspiration may be used but it is recommended that a plastic suction tip should be used when in proximity of the probe tip.Conclusion: based on the information provided, there does not appear to be a malfunction of the device that caused or contributed to the adverse event.There is no definitive root cause.A potential root cause is that the device was used in a manner inconsistent with manufacturer recommendations.
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