The Outcomes Following Revision of Monoblock Metal on Metal Acetabular Components for Painful Micromotion in the Absence of Adverse Local Tissue Reaction to Metal

Background

Revision hip arthroplasty for metal-on-metal arthroplasty (MOMA) in the presence of an adverse local tissue reaction (ALTR) has been associated with compromised outcomes. We hypothesized that revision of MOMA for painful micromotion of the cup, in the absence of ALTR, would have a more favorable outcome.

Methods

We reviewed our database for Durom acetabular shell revision with minimum 24 months (24 months to 8 years) follow-up. Patients with a diagnosis of painful micromotion in the absence of pseudotumor was identified.

Results

At mid-term follow-up, 71 patients had undergone revision of a Durom MOMA. Twenty-seven of these (38%) were for painful micromotion (9 total hip arthroplasty, 18 hip resurfacing) of the cup alone. Following revision surgery, all patients reported resolution of the preoperative pain, as well as satisfactory outcome measures (mean scores: The Western Ontario and McMaster Universities Arthritis Index [WOMAC] 84.6, oxford hip score 84.7, Short Form Health Survey (SF-16) 51, University of California, Los Angeles (UCLA) 7.3). Radiologically, all cases demonstrated osseointegration of the revision shells; 1 case had zone-3 radiolucency that was nonprogressive. One patient had a dislocation treated by closed reduction at 10 weeks.

Conclusion

Revision MOMA for painful micromotion of the shell in the absence of ALTR is not similar to revision for ALTR and is associated with predictable improvement in pain and quality of life.