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Patient 1
MANUFACTURING SITE EVALUATION: NO PRODUCT AT HAND. THE INVESTIGATION WAS PERFORMED BY EXPONENT. INVESTIGATION: THE ARTICULATING SURFACE OF THE POLYETHYLENE INSERTS HAD EVIDENCE OF MACHINING MARKS AND MULTIDIRECTIONAL SCRATCHES. ALL THREE COMPONENTS HAD EVIDENCE OF DAMAGE CONSISTENT WITH IMPINGEMENT. OVERALL THE RESULTS OF THE STAGE I ANALYSIS ARE CONSISTENT WITH DEVICES HAVING A SHORT IMPLANTATION TIME, IATROGENIC DAMAGE, AND IMPINGEMENT. STAGE III ANALYSIS WAS CONDUCTED TO ASSESS THE CONDITION OF THE POLYETHYLENE INSERT. STAGE III ANALYSIS FOUND A LOW OXIDATION LEVEL OF THE INSERT (OI < 1) AND MECHANICAL PROPERTIES CONSISTENT WITH THIS LEVEL OF OXIDATION. HISTOLOGY ANALYSIS DEMONSTRATED TISSUES COMPOSED OF FIBROUS TISSUE AND BONE. BIREFRINGENT AND METAL PARTICLES WERE OBSERVED. ONE SAMPLE SHOWED EVIDENCE OF IMPLANT MATERIAL THAT MAY HAVE FRAGMENTED OFF THE DEVICE DURING RETRIEVAL. ALVAL SCORES RANGED FROM 2 TO 6 FOR ALL TISSUES EVALUATED. THE ALVAL SCORE WOULD GENERALLY BE CONSIDERED LOW TO MODERATE WHEN COMPARED WITH TISSUES FROM HIP PATIENTS DEMONSTRATING DEVICE-MATERIAL RELATED TISSUE REACTION (E.G., LOW = 0-4; MODERATE = 5-8; HIGH = 9-10)2; HOWEVER, COMPARING THESE VALUES TO CAMPBELL, 2010 IS LIMITED BECAUSE THE ORIGINAL SCORING SYSTEM IS NOT INTENDED FOR USE IN THE SPINE. BATCH HISTORY REVIEW: BECAUSE THE BATCH OF THE PE- INLAY (SW965) IS FURTHER ON UNKNOWN, A BATCH HISTORY REVIEW IS NOT POSSIBLE. THE MANUFACTURING DOCUMENTS OF THE OTHER COMPONENTS (SW981K / SW986K) HAS BEEN CHECKED AND FOUND TO BE ACCORDING TO SPECIFICATION VALID DURING THE TIME OF PRODUCTION. THERE ARE NO FURTHER COMPLAINTS WITH THE KNOWN LOTS AT HAND. CONCLUSION AND ROOT CAUSE: THE ROOT CAUSE FOR THE PROBLEM IS MOST PROBABLY USAGE AND / OR PATIENT RELATED. RATIONALE: BECAUSE THERE IS ONLY MINOR INFORMATION AVAILABLE, A DEFINITIVE ROOT CAUSE ANALYSIS IS NOT POSSIBLE. FOLLOWING CAUSES ARE POSSIBLE: WRONG SYSTEM CONFIGURATION SELECTED BY THE USER, WRONG IMPLANT SIZE CHOSEN BY THE USER, END PLATE FORMED TOO STRONG BY THE USER, DESIGN LAYOUT UNSUITABLE, INADEQUATE PATIENT BEHAVIOUR, THE INVESTIGATION AT "EXPONENT" DID NOT REVEAL ANY RELEVANT PRODUCT DEVIATIONS. A MATERIAL DEFECT OR MANUFACTURING ERROR CAN BE EXCLUDED. CORRECTIVE ACTION: ACCORDING TO (B)(4) THERE IS NO CAPA NECESSARY.