Off-Label Use in Orthopaedic Surgery

Clinical compatibility of magnetic resonance imaging with magnetic intramedullary nails: a feasibility study

INTRODUCTION

The use of magnetic resonance imaging (MRI) with a magnetic intramedullary lengthening nail in place is contraindicated per the manufacturer due to the concern of implant activation and migration. A prior in vitro study did not confirm these complications only noting that a 3.0 T MRI weakened the internal magnet. Therefore, a retrospective analysis of patients who underwent an MRI with a magnetic nail in place was performed to determine if any adverse effects occurred in the clinical setting.

MATERIALS AND METHODS

A retrospective review of all patients who underwent an MRI with a magnetic lengthening nail in place was performed. The time spent being imaged in the MRI, number of times the patient entered the MRI suite, and the images obtained were recorded. Radiographs were performed before and after the MRI to determine if any hardware complications occurred. The patients were monitored for any adverse symptoms while they were in the suite.

RESULTS

A total of 12 patients with 13 nails were identified. Two patients underwent imaging with a 3.0 T MRI while the remaining 10 underwent imaging with a 1.5 T MRI. Each patient entered the MRI suite 2.1 times and spent an average of 84.7 min being imaged in the MRI (range 21-494). No patients noted any adverse symptoms related to the nail while in the suite and no hardware complications were identified.

CONCLUSION

MRI appears to be safe with a magnetic nail in place and did not result in any complications. Given the manufacturer's recommendations, informed consent should be obtained prior to an MRI being performed and a 3.0 T MRI should be avoided when possible if further activation of the nail is required.

Robotic-Assisted Conversion of a Failed Medial Unicompartmental Knee Arthroplasty to Total Knee Arthroplasty: A Case Report

CASE

An 81-year-old man with a history of left medial unicompartmental knee arthroplasty (mUKA) 8 years prior presented to the outpatient clinic with gradually increasing medial left knee pain of 6 years of duration. He underwent left conversion robotic-assisted total knee arthroplasty (RA TKA). At 1-year follow-up, the patient reported satisfactory clinical outcomes and excellent component alignment on x-rays.

CONCLUSION

This case highlights using RA TKA for failed mUKA as a viable and promising conversion arthroplasty alternative technique that may improve surgical outcomes by enhancing implant alignment and positioning, protecting the soft tissues, and preserving bone stock.

[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

Feasibility of the Inner-Side-Out Use of the LC-DCP for Periprosthetic Femoral Fracture in Total Hip Arthroplasty

BACKGROUND

The optimal technique for plate fixation to treat type B and C periprosthetic femoral fractures (PFFs) is unclear. The purpose of this study is to evaluate the radiographic results of inner-side-out limited contact dynamic compression plate (LC-DCP) to treat PFFs during or after total hip arthroplasty (THA).

METHODS

This retrospective study comprised of four men and six women with an average age of 64.7 years who underwent open reduction and internal fixation with an inner-side-out LC-DCP technique to treat PFFs; the reduction was maintained preliminary with the use of contoured plate and cables, and the grooves on the undersurface of LC-DCP for limited contact was used to hold and prevent the cables from slippage during tightening the cables. There were five intraoperative and five postoperative PFFs after THA. According to the Vancouver classification, the intraoperative PFFs included type B2 in two, B3 in one and C3 in two patients while postoperative PFFs were categorized into type B1 in one, type B2 in two and type C in two patients. The mean follow-up duration was 5.9 years (range 1-10.4). We evaluated radiographic union and complications after index operation.

RESULTS

All patients demonstrated radiographic bone union at an average follow-up duration of 4.4 months (range 3-8). Two patients showed stem subsidence after revision THA and one patient demonstrated a subsequent peri-implant fracture around the distal end of plate after union of the initial PPF; one patient underwent re-revision THA for stem loosening while another patient went through refixation for the peri-implant fracture. There was no nonunion, infection, nerve injury, or dislocation.

CONCLUSION

The inner-side-out LC-DCP technique showed satisfactory radiographic outcome. In certain situations where locking plates are not available, this technique might be a useful alternative for treating type B and C PFFs.