THA Re-revision Risk-Dual-Mobility or Large Femoral Head Bearings?

Are dual-mobility constructs or large femoral head bearings (≥ 36mm) better at reducing the risk of dislocation among patients who had revision THA for aseptic causes after a primary THA performed for osteoarthritis?

To answer this, a team from Australia analyzed data from their country’s joint replacement registry. Their work, “In Revision THA, Is the Re-revision Risk for Dislocation and Aseptic Causes Greater in Dual-mobility Constructs or Large Femoral Head Bearings? A Study from the Australian Orthopaedic Association National Joint Replacement Registry,” appears in the June 1, 2022, edition of Clinical Orthopaedics and Related Research.

Co-author Wayne Hoskins MBBS (Hons), an orthopedic surgeon with the University of Melbourne and Traumaplasty Melbourne in Australia, explained the genesis of this study to OTW: “Prosthesis dislocation is one the most common causes of re-revision after revision THA. Dual-mobility constructs and large femoral head bearings are two known common options for reducing this risk.”

“The prosthesis option that reduces the risk of prosthesis dislocation and proportion of all-cause re-revision surgery is not known.”

“Most comparative studies in THA have compared the outcomes of dual-mobility constructs with those of THA performed with a variety of femoral head sizes, and not restricted to large femoral head sizes. Of the studies that exist, few are multi-surgeon and multi-institution, and only a few studies have evaluated these constructs in the setting of revision THA.”

The study began in January 2008, when the first dual-mobility prosthesis was recorded and ran until December 2019. Included were 502 dual-mobility constructs and 793 large femoral head bearings. The researchers excluded primary prostheses with metal-on-metal bearings due to their established higher proportion of revision.

“Studying whether dual mobility constructs or large femoral head sizes are the preferred option in revision THA is difficult without adequately large patient numbers to allow adjusting for confounders and sufficiently complete follow-up is difficult outside of national joint replacement registries,” said Dr. Hoskins. “We did not identify any difference in the proportion of re-revisions for prosthesis dislocation or all aseptic causes when dual-mobility constructs and large femoral head bearings were compared (adjusted for age, gender, and femoral fixation). There was also no difference when procedures were stratified by acetabular component size < 58mm or 58mm or greater.”

“Based on these findings, future research should investigate factors behind surgeon decision-making or determine if a selection bias is present. Long-term follow-up is required to assess whether complications develop with either implant or whether a difference in re-revision rates becomes apparent. Ultimately, prospective research in the form of randomized controlled trials is needed.”