Cold saline lavage for removal of incarcerated porous ingrowth stems

A patient with a history of total knee arthroplasty and 5 subsequent revisions presented with pain. His preoperative construct consisted of a revision implant with porous in-growth stem extensions. He was indicated for revision surgery for a painful implant with progressive arthrofibrosis. The surgery proceeded uneventfully until we were unable to loosen the proximal portion of the ingrown femoral stem. After the distal femur was removed, a trephine was used to break the bone ingrowth from the distal portion of the stem. Flexible osteotomes were used to loosen the bone-prosthetic interface, but they were unable to penetrate deep enough, and they eventually bent under the applied loads. Nonflexible osteotomes were also used without success, and we were still unable to remove the stem from within the femur. Slap hammers, vice grips, and other devices were used to try to remove the stem, but attempts were unsuccessful. We hung a 3-liter bag of ice-cold (4 °C) saline and ran all 3 liters of saline, under gravity pressure, retrograde down the femoral shaft in an attempt to contract the metal and allow for the removal of the stem. We then attached a stem extension screw to the incarcerated femoral stem and were able to remove it with minimal effort using a back-slap device. We inspected the prosthesis and found no abnormalities of the stem to explain its incarceration and no iatrogenic perforations in the femur. This case demonstrates a useful technique that should be kept in a revision surgeon's armamentarium for the removal of incarcerated porous ingrowth stems.