Sunday, April 14, 2013

High Complication Rate After Revision of Large-head Metal-on-metal Total Hip Arthroplasty

This article is part of Hip
 

Abstract

Background

Previous studies have indicated poor outcomes in patients having revision of hip resurfacing resulting from adverse local tissue reaction and pseudotumor.

Questions/purposes

We reviewed all patients at our institution who had revision of failed large-head metal-on-metal total hip arthroplasty to determine (1) complications including reoperations; (2) radiologic outcomes; and (3) changes in serum ions after removal of the metal bearing.

Methods

From our research database, we identified 32 hips in 30 patients. Revisions were performed through a posterior approach; 17 were performed with a titanium fiber-metal shell and 15 with a porous tantalum shell, and 29 of the 32 revisions were performed with large (36- or 40-mm) femoral heads. Clinical records were reviewed and interviews conducted in the clinic or by telephone. Nineteen hips had a pre- or intraoperative diagnosis of adverse local tissue reaction, three had deep infection, and 10 had loosening of the acetabular component.

Results

Major complications occurred in 12 (38%) of the 32 revisions. Nine of 32 hips (28%) sustained dislocations. Four of 17 fiber-metal acetabular components failed to ingrow; none of the porous tantalum cups failed to ingrow. Seven repeat revisions were performed in six patients: three for acetabular loosening, three for recurrent dislocation, and one for recurrent adverse local tissue reaction. The mean WOMAC pain score was 78 of 100 and the function score was 83 of 100. Metal ion levels decreased after revision in most patients.

Conclusions

As a result of the high rate of failure of the fiber metal cups, we have elected to use an enhanced fixation surface with a high-porosity cup for revision of these cases. We observed a high rate of dislocation despite the use of 36-mm and 40-mm heads.

Level of Evidence

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
 
 
Authors relationships:
Each author (JTM, BAM, CPD, DSG) certifies that he or she has or may receive payments or benefits in any one year, an amount of USD 10,000–USD 100,000 (eg, serve as a consultant [JTM, BAM, CPD, DSG] or speakers bureaus [CPD]) from a commercial entity (Zimmer, Inc, Warsaw, IN, USA); and an amount of USD 10,000–USD 100,000 (speakers bureaus [CPD]) from a commercial entity (DePuy Synthes Canada Ltd, Markham, Ontario, Canada) related to this work. The institution of the authors (JTM, BAM, CPD, DSG) has received funding from Zimmer Inc (Warsaw, IN, USA), DePuy Synthes Canada Ltd, Johnson & Johnson (Canada) Inc (Markham, Ontario, Canada), Stryker Canada (Hamilton, Ontario, Canada), and Bayer Inc (Toronto, Ontario, Canada).
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request.
Clinical Orthopaedics and Related Research neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA-approval status, of any drug or device prior to clinical use.
Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.

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