Fretting and Corrosion at the Backside of Modular Cobalt Chromium Acetabular Inserts: A Retrieval Analysis.
Adverse local tissue reaction formation has been suggested to occur with the Modular Dual Mobility (MDM) acetabular design. Few reports in the literature have evaluated fretting and corrosion damage between the acetabular shell and modular metal inserts in this modular system. We evaluated a series of 18 retrieved cobalt chromium MDM inserts for evidence of fretting and corrosion.



We assessed the backsides of 18 MDM components for evidence of fretting and corrosion in polar and taper regions based on previously established methods. We collected and assessed 30 similarly designed modular inserts retrieved from metal-on-metal (MoM) total hip arthroplasties as a control.



No specific pattern of fretting or corrosion was identified on the MDM inserts. Both fretting and corrosion were significantly greater in the MoM cohort than the MDM cohort, driven by higher fretting and corrosion scores in the engaged taper region of the MoM inserts.



MoM components demonstrated more fretting and corrosion than MDM designs, specifically at the taper region, likely driven by differences in the taper engagement mechanism and geometry among the insert designs. The lack of significant fretting and corrosion observed in the MDM inserts are inconsistent with recent claims that this interface may produce clinically significant metallosis and adverse local tissue reactions.
Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, New York, New York.
T David
TD
Tarity
Department of Biomechanics, Hospital for Special Surgery, New York, New York.
Chelsea N
CN
Koch
Healthcare Research Institute, Hospital for Special Surgery, New York, New York.
Jayme C
JC
Burket
Department of Biomechanics, Hospital for Special Surgery, New York, New York.
Timothy M
TM
Wright
Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, New York, New York.
Geoffrey H
GH
Westrich
D000077:Acetabulum / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation; D002857:Chromium; D003035:Cobalt; D015331:Cohort Studies; D003343:Corrosion; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D061825:Metal-on-Metal Joint Prostheses / Q000706:statistics & numerical data*; D008670:Metals; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*
D008670:Metals; D002857:Chromium; D003035:Cobalt
corrosion; dual mobility; fretting; metallosis; retrieval analysis; total hip arthroplasty