Heat the implant. Soften the cement.
MIEAS is an induction system in preclinical development for removing cemented implants during revision surgery, starting with the knee.
Getting a well-fixed cemented implant out is one of the most demanding steps of a revision.
Most knee replacements are fixed to bone with acrylic bone cement. When one fails, from loosening, wear, instability or infection, the old component usually has to come out before a new one can go in. The hard case is a component the cement still holds well.
If the cement is still holding, surgeons work the implant free with thin osteotomes, saws and high-speed burrs, and bone can be broken or lost in that step. Surgical reviews describe getting a well-fixed cemented stem extension out as long and difficult work.
If a cemented stem will not come free, surgeons may also run a trephine reamer, a hollow cutter that fits over the stem, to clear the cement around it. A knee revision review lists it only as an option “if available,” warns that working a well-fixed stem out through the canal can be dangerous, and notes that most such cases need the bone opened with a window or a longer cut. Surgeons who revise tumor implants around the knee have written that, when a well-fixed stem has broken inside the bone, trephines are “often unsuccessful for cemented or for bowed stems” and “excessively destructive to the remaining cortical bone.”
In one center’s series of 55 well-fixed cemented stems removed at repeat knee revision, 18% were removed by cutting the bone open (osteotomy), and 9% of stem removals broke bone. In first revisions where only the tibial component was loose, surgeons who also took out the well-fixed femoral component found substantial bone loss at its removal in 5 of 76 knees (7%), and revising both components took about an hour longer than revising the tibia alone.
Bieganowski et al., Knee Surg Relat Res 2022;34:30, PMID 35725586. Pasquier et al., Orthop Traumatol Surg Res 2020;106(1S):S135–S147, PMID 31812635. Ng et al., Open Orthop J 2017;11:234–238, PMID 28567150: tumor implants (megaprostheses) of the distal femur and proximal tibia, well-fixed stems broken inside the bone; the authors’ view, not a measured outcome. Maslaris et al., Arch Orthop Trauma Surg 2023;143:469–479, PMID 35930052: all repeat revisions, three in four for infection. Martin et al., Bone Joint J 2020;102-B(6 Supple A):123–128, PMID 32475265: one center, aseptic first revisions; median 204.5 vs 152 minutes.
Induction heating, aimed at the implant.
It is the same physics an induction cooktop uses to heat a pan. The engineering challenge is control. The aim is to heat the implant enough to soften the cement right next to it while limiting the heat that reaches the surrounding bone and soft tissue. In the operation, MIEAS is designed for the step after the joint is exposed and before the old component is extracted.
A field around the joint
The system generates a low-frequency electromagnetic field around the joint that holds the implant.
The metal heats
The field induces electric currents in the metal implant, and those currents heat it. The implant itself is the source of the heat.
The cement softens
The bone cement right next to the implant softens. The aim is for the implant to come free with less force than chisels and burrs need and with less bone lost, shortening time in the operating room and under anesthesia.
Softening the cement is how the implant is released, not a way of removing the cement. Cement left on the bone, where it has to come out, is still cleared with the usual techniques.
Instrumented bench work.
In the 2024 hip run, a thermocouple on the implant recorded its temperature and an infrared camera showed how the heat spread. The knee run in the same session was not instrumented. These are early bench tests, not clinical results.
Where MIEAS stands, October 2026.
FDA Q‑Submissions
MicoCalo has completed an initial Q‑Submission with FDA and is now working on a second Q‑Submission.
Not authorized for use
MIEAS is in preclinical development. It has been tested only on the bench and has not been used in patients. It has no FDA marketing authorization, is not CE marked, and is not for sale in any market.
Patent pending
MicoCalo’s international (PCT) patent application has entered the national phase at the US Patent and Trademark Office and the regional phase at the European Patent Office. No patent has been granted yet.