Letter to the Editor: Poor Survivorship and Frequent Complications at a Median of 10 Years After Metal-on-Metal Hip Resurfacing Revision
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KeywordsFemoral Component Femoral Neck Fracture Acetabular Component Unicompartmental Knee Replacement Femoral Head Size
To the Editor
The learning curve report from Matharu and colleagues  highlights how a workable revision strategy should be included for any adopted procedure. Dr. Leopold expands on this theme in his Editor’s Spotlight .
Large-diameter metal-on-metal (MoM) THA as a MoM hip resurfacing (MoMHR) revision option failed gradually over time, accounting for 11 of the authors’ 20 rerevisions. Additionally, revising the femoral head size to 28 mm or 32 mm, and performing seven metal-on-polyethylene total hip replacements when the soft tissues are damaged by a pseudotumor, resulted in five recurrent dislocations with rerevisions. Removing a well-fixed acetabular component resulted in aseptic loosening and rerevisions in two hips . When the authors changed their techniques, MoMHR revision improved to 76% survivorship, closer to their 82% survivorship for their total hip replacements .
There are other revision methods available. The authors erred in describing my work using a crosslinked polyethylene acetabular component in revision of a metal hip resurfacing by stating that I cement the polyethylene into the MoMHR shell. This is not what I do and it is not recommended. I use a standard two-piece acetabular shell that very closely matches the resurfacing femoral component . The crosslinked liner is larger and the shell is thinner than is used typically for total hip replacement. Hip resurfacing and MoMHR are not synonymous. I, and others [1, 3, 8], have performed polyethylene hip resurfacing for many years and now use highly-crosslinked polyethylene.
The authors also comment on my work using a dual-mobility femoral component with a retained well-fixed and well-oriented MoMHR acetabular component that has limited damage . This mobile-bearing concept is not new. Tripolar femoral prostheses can be used for femoral neck fractures or avascular necrosis after hip resurfacing when the acetabular component is polyethylene rather than metal. I first used this technique 18 years ago with crosslinked polyethylene and it was used more than 30 years ago with conventional polyethylene . For MoMHR, I use the current dual-mobility prostheses. Several centers now use this method .
Matharu and colleagues reported on bias in unicompartmental knee replacement. It is equally important to consider selection, reporting, and measurement bias in hip resurfacing. For example, some analytics report femoral neck fracture is an implant-related failure for resurfacing but a periprosthetic total hip replacement fracture is not .
As the Editor’s Spotlight points out , we moved too quickly in adopting large-diameter MoM total hip replacement. We should not make the same mistake by discarding hip resurfacing, which is beneficial for young active patients whose activities and expectations exceed outcomes of total hip replacement . There remains a role for a bone-preserving method that has a smaller volume of implanted material. Additionally, resurfacing can be performed when the medullary canal is blocked.
- 10.Scheerlinck T, Casteleyn PP. “Tripolar” hip arthroplasty for failed hip resurfacing: nineteen years follow-up. Acta Orthop Belg. 2001;67:407–411.Google Scholar