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Publication Date

11-6-2017

Keywords

surgery, tissue, hip implant, anatomy, device recall

Abstract

Background: The Stryker Rejuvenate modular hip implant device allows for greater versatility in matching a patient’s anatomy than conventional implants. Device recalls and in vivo metal hypersensitivity after total hip arthroplasty (THA) are common. However, recall of the Rejuvenate implant represents one of the largest recall volumes to date, highlighting our uncertainty regarding causes of device metal fretting/corrosion and adverse local tissue reaction (ALTR). While devices with metal-on-metal bearings historically were culprits for release of metal debris, more recently developed modular-neck devices add opportunity for adjacent metal components to rub together. With the Rejuvenate device, corrosion or fretting likely occurs at the cobalt-chromium neck and titanium stem interface. Cobalt (Co) and chromium (Cr) particles then irritate tissues locally and cause a gradation of problems or indications of ALTR.

Purpose: Quantify the effect of revision surgery on ALTR grade in patients who previously underwent THA receiving the recalled Rejuvenate hip implant.

Methods: We conducted a prospective observational study of all patients who underwent THA performed by a single Aurora Health Care orthopedic surgeon using the Rejuvenate implant. Following implant recall in July 2012, patients were notified via letter/phone and asked to visit regularly (every 3–6 months) for lab work, imaging and device assessment. Using repeated measures multinomial logit analysis we examined the effect of revision surgery on abnormal grade of ALTR (ie, grade 1–4 vs 0), adjusting for patient characteristics, device specifications and indicators of post-THA complication (serum Cr ion, Co ion, C-reactive protein, erythrocyte sedimentation rate).

Results: In total, 162 hips and 152 unique patients underwent THA during September 2009–May 2012, with 78 hips subsequently revised during 2012–2015. Patients were of median age 62 years (range: 32–90), nearly all non-Hispanic white (89%) and mostly female (58%). Several variables were significantly associated (P < 0.05) with ALTR grade, including occurrence of complication symptoms (eg, pain), patient age, and Co ion concentrations. Revision surgery was the most strongly associated variable with ALTR, with 5 times greater odds of abnormal grade when not undergoing revision (odds ratio: 5.68, 95% confidence interval: 2.69–11.9).

Conclusion: Within Aurora, patients who underwent THA with the Stryker Rejuvenate hip implant often experienced the complications of ALTR, but revision surgery reduced the ALTR grade.