To mix or not to mix? Medicolegal implications of mixed components in total hip arthroplasty

Revision radiocapitellar arthroplasty by mismatched implant components - A salvage option: A report of two cases with a minimum three-year follow-up

Radiocapitellar arthroplasty has been shown to improve pain and function in patients with a degenerative joint. Due to problems with the loosening of the radial head component, one of the few available systems was removed from the global market. This offered specific challenges in terms of treatment strategies when one or both components of a system that is no longer available fail. Due to the very different geometry of the capitellar implant, revision of the capitellar component would require a complex procedure, likely requiring bone graft and a high chance of early failure, leaving resection or interposition arthroplasty as the only available option. Although implant mismatch is common practice in hip and knee arthroplasty with satisfactory results, it should remain a salvage option as the off-label use of components gives rise to several medicolegal implications. We report two cases of radiocapitellar arthroplasty partial revision, by replacing only the radial head component with an implant from another system while keeping the well-fixed original capitellar component in place. At a minimum of three-year follow-up, both cases improved from poor to good and excellent Mayo elbow performance scores. There were no signs of implant failure on standard radiographs.

Revision Dual Mobility Constructs With Unmatched Acetabular and Femoral Components Do Not Increase Failure Rate

BACKGROUND

Dual mobility (DM) constructs for revision total hip arthroplasty (THA) have continued to grow in popularity to mitigate instability. This benefit comes at the cost of potential unique modes of failure, and there are theoretical concerns that combining femoral and acetabular components from different manufacturers could lead to increased failure rates. We aimed to investigate rates of reoperation between matched and unmatched DM implants used in revision THA.

METHODS

We retrospectively reviewed 217 revision THAs performed with DM constructs between July 2012 and September 2021 at a single institution. Dual mobility (DM) constructs were classified as "matched" if the acetabular and femoral components were manufactured by the same company. They were classified as "unmatched" if the acetabular and femoral components were manufactured by different companies. The primary outcome was reoperation for any reason.

RESULTS

There were 136 matched DM constructs and 81 unmatched constructs. Average follow-up was 4.6 years (range, 2.0 to 9.6 years). There was no difference in reoperation rate between matched and unmatched groups (11.0 versus 13.6%, P = .576). The most common reasons for reoperation in both groups were instability and periprosthetic joint infection. There was 1 revision for intraprosthetic dislocation in the matched group.

CONCLUSIONS

The use of unmatched DM components in revision THA was common and did not increase the risk of reoperation at an average of 4.6-year follow-up. This information can be helpful in operative planning, but further research on long-term survival will be necessary.

[Partial or full component exchange in hip revision? : The relevance of off-label use and mix & match]

Off-label use is frequently practiced in hip revision arthroplasty, as there may be indications for the application of implants for purposes outside the one the manufacturers intended (i.e. large bone and soft tissue defects, obesity). Patients may also benefit from selective application of mix & match in hip revision, when the exchange of one component only is necessary and the invasiveness of surgery can be reduced. Currently, there are no formal guidelines for these situations. Therefore, within a recent EFORT initiative, evidence- and consensus-based recommendations have been developed for the safe application of off-label use and mix & match in revision hip and knee arthroplasty.

EFORT recommendations for off-label use, mix & match and mismatch in hip and knee arthroplasty

Off-label use is frequently practiced in primary and revision arthroplasty, as there may be indications for the application of implants for purposes outside the one the manufacturers intended.

Under certain circumstances, patients may benefit from selective application of mix & match. This can refer to primary hip arthroplasty (if evidence suggests that the combination of devices from different manufacturers has superior results) and revision hip or knee arthroplasty (when the exchange of one component only is necessary and the invasiveness of surgery can be reduced).

Within the EFORT ‘Implant and Patient Safety Initiative’, evidence- and consensus-based recommendations have been developed for the safe application of off-label use and mix & match in primary as well as revision hip and knee arthroplasty.

Prior to the application of a medical device for hip or knee arthroplasty off-label and within a mix & match situation, surgeons should balance the risks and benefits to the patient, obtain informed consent, and document the decision process appropriately.

Nevertheless, it is crucial for surgeons to only combine implants that are compatible. Mismatch of components, where their sizes or connections do not fit, may have catastrophic effects and is a surgical mistake.

Surgeons must be fully aware of the features of the components that they use in off-label indications or during mix & match applications, must be appropriately trained and must audit their results.

Considering the frequent practice of off-label and mix & match as well as the potential medico-legal issues, further research is necessary to obtain more data about the appropriate indications and outcomes for those procedures.

Cite this article: EFORT Open Rev 2021;6:982-1005. DOI: 10.1302/2058-5241.6.210080

Medico-Legal Issues Related to Hip and Knee Arthroplasty: A Literature Review Including the Indian Scenario

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are commonly performed surgeries worldwide. The number of joint replacement surgeries being performed has increased considerably over the past two decades, but it has also seen an increase in litigation associated with it. The purpose of our study was to review and consolidate literature regarding medico-legal issues pertaining to THA and TKA cases. We looked at the causes of litigation, medico legal aspects of pre-operative requirements, optimisation of medical condition, indications and contraindications for arthroplasty, informed consent, implants, mixing of components from different manufacturers and post-operative rehabilitation. We also wanted to analyse available literature and legal proceedings regarding these cases in India specifically.