During a mako hip case, manual reaming was enabled.The medial distance remaining number showed we still had over 3mm to go, however the surgeon went through the medial wall.Additionally, the 3d bone model showed that we went through the medial wall, while the medial distance to ream number was still over 3mm.No surgical delay.Case type / application: ltha.Update 03/june/2021 wg: as per mps response, surgeon addressed the issue by manually inferiorizing the cup.Surgical delay 10 minutes.
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During a mako hip case, manual reaming was enabled.The medial distance remaining number showed we still had over 3mm to go, however the surgeon went through the medial wall.Additionally, the 3d bone model showed that we went through the medial wall, while the medial distance to ream number was still over 3mm.No surgical delay.Case type / application: ltha update 03/june/2021 wg: as per mps response, surgeon addressed the issue by manually inferiorizing the cup.Surgical delay 10 minutes.
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Reported event: an event regarding inaccurate reaming involving a mako tha software was reported.The event was confirmed.Method & results: -product evaluation and results: review of the case session files noted the following: implant plan review of the cup plan showed the plan was considerably anterior and inferior relative to the native acetabulum and would have been difficult to achieve under haptics without the acetabulum and osteophytes pushing the reamer posterior relative to the plan, especially if single-stage reaming.The plan showed breaching of the anterior wall of the acetabulum.Pelvic bone registration: preliminary review of bone registration confirmed that it was acceptable and not the root cause of the issue.Bone preparation and reamer location: per the log files, bone preparation began in manual reaming (no stereotactic boundary) with a single reamer size (58).Re-creation of the burr path confirmed that the reamer would have gone through the medial wall.Because ¿manual reaming¿ was enabled, power to reamer would not have been cut nor would the stereotactic boundary have prevented progress of the reamer through the medial wall.The path of reamer is considerably posterior and superior to the planned target position.At the deepest reamed point, the reamer center is 1.8mm lateral, 3.1mm posterior, and 10.2mm superior to the target center.So even though the reamer went considerably deeper than the planned target, it was still lateral to the target.The reaming screen would have indicated 2mm medial, 3mm anterior, and 10mm inferior to go at the deepest reamed point.Cup impaction: review of the logs showed the deepest cup impaction ¿distance remaining¿ value as 12.4mm which aligns with the event description stating that the cup was interiorized relative to the reamed resection.Conclusion: the system appears to have been performing as intended.The anterior/inferior cup plan combined with the lack of stereotactic boundary during manual reaming to prevent over-reaming led to a resection considerably superior and deeper relative to the plan, yet still lateral to the target, aligning with the event description that ¿medial distance to ream number was still over 3mm¿.Recommendation: better center the cup plan within the acetabulum using ct and reaming views so that reaming under stereotactic boundary control is possible.If difficulty single-stage reaming, remove any obstructing osteophytes, reduce the reamer size to ease entry into the haptic, then upsize the reamer sequentially.If manually reaming cannot be avoided, pay attention to all directions of remaining distance to ream (m/l, a/p, and s/i) as the medial value is not the only direction related to reaming depth.-clinician review: no medical records were received for review with a clinical consultant.-product history review: a review of device history records shows that rob943 was inspected and the quality inspection procedures were completed with no reported discrepancies -complaint history review: a review of complaints in trackwise related to p/n 219999, robot number: rob943 shows 0 similar complaints for tha software - inaccurate reaming.Conclusions: based on the analysis of the relevant log files and session files, the alleged failure mode was confirmed to have been caused due to user error.No additional investigation or specific actions are required.If additional information is received, then the complaint will be reopened.
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