PROFEMUR® MODULAR FEMORAL NECK

Additional Manufacturer Narrative

THIS EVENT WILL BE UPDATED ONCE THE INVESTIGATION IS COMPLETE. TRENDS WILL BE EVALUATED.

Description of Event or Problem

ALLEGEDLY, REVISION DUE TO UNUSUAL WEAR ON THE MODULAR NECK.

Additional Manufacturer Narrative

THE ALLEGED COMPLAINT IS CONFIRMED. THE REVISED PRODUCTS HAVE NOT BEEN RETURNED TO MPO FOR INVESTIGATION. MPO RECEIVED AN IMAGE OF THE EXPLANTED MODULAR FEMORAL NECK. MPO CONFIRMS THAT THE PROFEMUR TITANIUM MODULAR NECK HAS EXPERIENCED SUBSTANTIAL WEAR OF THE PROXIMAL REGION OF THE HEAD-NECK TAPER AND NECK BODY, AND THE DISTAL TAPER SHOWS EVIDENCE OF POSSIBLE FRETTING AND CORROSION. THE LOT INFORMATION WAS NOT PROVIDED BY THE REPORTING PERSON FOR THE MODULAR NECK OR MODULAR HEAD, AND IT IS NOT VISIBLE ON THE PROVIDED IMAGE. THE WEAR EXHIBITED BY THE MODULAR NECK IS NOT TYPICAL OF A PROPERLY ASSEMBLED PROXIMAL TAPER, AND THE AVAILABLE INFORMATION LIKELY SUGGESTS PROLONGED MAL-POSITIONING OF THE ENTIRE CONSTRUCT. THE TIME OF IMPLANTATION IS UNKNOWN. MPO DID NOT RECEIVE ANY RADIOGRAPHS TO REVIEW COMPONENT POSITIONING OVER TIME, NOR WERE ANY OTHER DETAILS AVAILABLE TO EVALUATE THE CIRCUMSTANCES OF THIS INCIDENT. BASED ON ALL FINDINGS, IT IS POSSIBLE THAT THE FEMORAL HEAD BECAME SEPARATED FROM THE PROXIMAL TAPER OF THE MODULAR NECK. UNDER THIS CIRCUMSTANCE, THE FEMORAL NECK COULD HAVE EXPERIENCED PROLONGED, UNINTENDED CONTACT WITH THE FEMORAL HEAD AND/OR ACETABULAR CUP IN AN IMPINGEMENT CONDITION. SEPARATION BETWEEN THE FEMORAL HEAD AND MODULAR NECK ASSEMBLY IS NOT EXPECTED IF THE JOINT AND CONSTRUCT REMAIN PROPERLY ALIGNED AND TENSIONED. HOWEVER, VARIOUS FACTORS CAN AFFECT THE PERFORMANCE OF TAPER LOCKING MECHANISMS IN VIVO, INCLUDING IMPLANT SELECTION, IMPACTION TECHNIQUE, IMPLANT FIXATION AND ALIGNMENT, TISSUE LAXITY, THE POTENTIAL FOR MICROMOTION AT THE TAPER CONNECTION, TRAUMATIC EVENTS, AMONG OTHER FACTORS. AS NOTED IN THE MPO CURRENT HIP SYSTEMS PACKAGE INSERT, 150803-9, "ALWAYS FOLLOW THE RECOMMENDED SURGICAL TECHNIQUE. FAILURE TO ADHERE TO THE ADVISED ASSEMBLY INSTRUCTIONS MAY HAVE POTENTIAL TO INCREASE RISK OF FRETTING CORROSION, FATIGUE FRACTURE OR DISASSOCIATION OF THE PRODUCT. PRIOR TO ASSEMBLY, SURGICAL DEBRIS AND FLUID MUST BE CLEANED FROM THE INTERIOR OF THE FEMALE SEAT TO ENSURE PROPER LOCKING. ENSURE COMPONENTS ARE FIRMLY SEATED TO PREVENT DISASSOCIATION. THE FEMORAL HEAD, NECK TAPER OF THE FEMORAL COMPONENT, MODULAR NECK TAPERS, BODY TAPER, FEMALE SEAT OF THE PROXIMAL BODY MUST BE CLEAN AND DRY BEFORE ASSEMBLY. IMPACT ACCORDING TO THE RECOMMENDED SURGICAL TECHNIQUE. SCRATCHING OF FEMORAL HEADS, MODULAR NECKS AND PROXIMAL AND DISTAL STEM TAPERS SHOULD BE AVOIDED. REPEATED ASSEMBLY AND DISASSEMBLY OF THESE COMPONENTS COULD COMPROMISE THE LOCKING ACTION OF THE TAPER JOINT." REGARDING THE PATIENT CARE AND MONITORING, "THE PATIENT SHOULD BE CAUTIONED TO LIMIT ACTIVITIES AND PROTECT THE REPLACED JOINT FROM UNREASONABLE STRESSES AND POSSIBLE LOOSENING, FRACTURE AND/OR WEAR, AND FOLLOW THE INSTRUCTIONS OF THE PHYSICIAN WITH RESPECT TO FOLLOW-UP CARE AND TREATMENT. LOOSENING OF THE COMPONENTS CAN RESULT IN INCREASED PRODUCTION OF WEAR PARTICLES, AS WELL AS DAMAGE TO THE BONE, MAKING SUCCESSFUL REVISION SURGERY MORE DIFFICULT. " NO OTHER CONCLUSIONS CAN BE MADE REGARDING THIS OCCURRENCE FROM THE AVAILABLE INFORMATION. MPO HAS NOT IDENTIFIED ANY TRENDS SPECIFIC TO THIS TYPE OF OCCURRENCE. THIS ISSUE WILL CONTINUE TO BE MONITORED THROUGH COMPLAINT TRACKING.