MOTO PARTIAL KNEE SYSTEM - MEDIAL

Description of Event or Problem

REVISION SURGERY DUE TO DISSOCIATION BETWEEN THE TIBIAL INSERT AND TIBIAL TRAY, WHICH WAS NOTICED DURING A KNEE ARTHROSCOPY PERFORMED DUE TO PERSISTENT PAIN APPROXIMATELY 1 YEAR AND 6 MONTHS AFTER PRIMARY SURGERY. THE SURGEON REVISED THE LINER SUCCESSFULLY.

Additional Manufacturer Narrative

BATCH REVIEW PERFORMED ON 16 JUN 2026 MOTO PARTIAL KNEE 02.18.TF2.RM MOTO MEDIAL TIBIAL TRAY S2 RM (K162084) LOT 2415030: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 22-JUL-2024. EXPIRATION DATE: 2029-JUL-04. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. MOTO PARTIAL KNEE 02.18.EIF2.09.RM MOTO MEDIAL E-CROSS TIBIAL INSERT S2 RM - H9 (K213071) LOT 2201773: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 24-MAR-2022. EXPIRATION DATE: 2027-FEB-27. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. VISUAL INSPECTION PERFORMED BY R&D PROJECT MANAGER REVISION SURGERY WAS PERFORMED APPROXIMATELY 1 AND A HALF YEARS (18 MONTHS) AFTER THE PRIMARY UKA DUE TO PERSISTENT PAIN ASSOCIATED WITH LOOSENING OF THE MOTO MEDIAL E-CROSS TIBIAL INSERT. PRIOR TO THE REVISION PROCEDURE, A KNEE ARTHROSCOPY WAS CONDUCTED, CONFIRMING A GAP BETWEEN THE TIBIAL PLATEAU AND LINER. A VIDEO DURING THE REVISION SURGERY IS AVAILABLE FOR EVALUATION. THE EXPLANTED TIBIAL INSERT, SUBMITTED FOR INVESTIGATION, SHOWED SIGNS OF WEAR ON THE ARTICULAR SURFACE, AS WELL AS DENTS AND SCRATCHES ON THE ANTERIOR AND INFERIOR ASPECTS, CONSISTENT WITH THE ABNORMAL MOVEMENT OBSERVED IN THE ARTHROSCOPY VIDEO. MOST NOTABLY, THE INSERT EXHIBITED SIGNIFICANT DAMAGE AND PLASTIC DEFORMATION OF THE ANTERIOR ENGAGEMENT MECHANISM, WHICH IS DESIGNED TO LOCK INTO THE TIBIAL BASEPLATE. ALTHOUGH IT IS NOT POSSIBLE TO GIVE A CERTAIN RECONSTRUCTION OF WHEN THE ANTERIOR ENGAGEMENT MECHANISM WAS DAMAGED, SUCH DAMAGE TO THE ANTERIOR LOCKING FEATURE COULD SUGGEST THAT, DURING INITIAL INSERTION AND ENGAGEMENT ATTEMPTS, THE COMPONENT MAY NOT HAVE BEEN PROPERLY ALIGNED OR FULLY SEATED WITHIN THE TIBIAL BASEPLATE. THIS MISALIGNMENT LIKELY PREVENTED CORRECT ANTERIOR ENGAGEMENT AND LED TO PLASTIC DEFORMATION OF THE LOCKING MECHANISM. THE RESULTING DEFORMATION WOULD HAVE COMPROMISED THE ABILITY TO ACHIEVE PROPER ENGAGEMENT AND STABLE FIXATION IN SUBSEQUENT ATTEMPTS. BASED ON VISUAL INSPECTION, THERE IS NO EVIDENCE TO INDICATE THAT THE EVENT WAS CAUSED BY A DEFECTIVE OR NON-COMPLIANT DEVICE. CLINICAL EVALUATION PERFORMED BY CLINICAL AFFAIRS DEPARTMENT THE COMPLAINT CONCERNS PAIN APPROXIMATELY 18 MONTHS AFTER MEDIAL PARTIAL KNEE ARTHROPLASTY, WITH INTRAOPERATIVE EVIDENCE OF TIBIAL INSERT LIFT-OFF / PARTIAL DISSOCIATION FROM THE TIBIAL TRAY AND SUBSEQUENT INSERT REPLACEMENT. THE AVAILABLE RADIOGRAPHS SHOW WELL-POSITIONED METALLIC COMPONENTS AND DO NOT INDICATE LOOSENING OR FRACTURE. FROM STANDARD X-RAYS WE CANNOT RELIABLY ASSESS THE RADIOTRANSPARENT POLYETHYLENE INSERT, BUT THE AVAILABLE INTRAOPERATIVE PICTURES CAN CONFIRM THAT THE ANTERIOR PART OF THE INSERT IS RAISED FROM THE TIBIAL TRAY. THE ROOT CAUSE CANNOT BE DETERMINED WITH THE INFORMATION AVAILABLE. POTENTIAL CONTRIBUTING FACTORS INCLUDE INCOMPLETE INITIAL SEATING, COUPLING OR LOCKING MECHANISM ISSUE, SOFT-TISSUE IMBALANCE/INSTABILITY, OR OTHER MULTIFACTORIAL BIOMECHANICAL CONDITIONS. WITH THE INFORMATION AT HAND, WE CANNOT MAKE A DEFINITIVE CONCLUSION. ROOT CAUSE:THE RETURNED TIBIAL INSERT SHOWED DAMAGE AND PLASTIC DEFORMATION OF THE ANTERIOR ENGAGEMENT MECHANISM, WHICH MAY BE CONSISTENT WITH INCORRECT ALIGNMENT AND/OR INCOMPLETE SEATING DURING ENGAGEMENT, POTENTIALLY COMPROMISING STABLE FIXATION AND LEADING TO MICROMOVEMENT AND LOOSENING, HOWEVER, THE AVAILABLE INFORMATION DOES NOT ALLOW A CERTAINTY OF WHEN THE DAMAGE OCCURRED. THE INVESTIGATION DOES NOT INDICATE ANY POTENTIAL MANUFACTURING RELATED ISSUE OR SYSTEMIC DEFICIENCY.