A novel use of a tibial cone in a proximal femoral replacement

Abstract

Revision total hip arthroplasty in the setting of severe femoral bone loss can be challenging, with salvage options often limited to modular tapered stems, allograft prosthetic composites, and megaprostheses. This case highlights a 79-year-old woman with 2 years of thigh pain who is 8 years status post a revision proximal femoral allograft prosthetic composite reconstruction. Radiographs demonstrated significant stem subsidence into the femoral condyle. In an attempt to avoid a total femoral replacement and spare her functioning native knee, a tibial cone was used in conjunction with a proximal femoral replacement to structurally fill the flaring femoral canal and serve as a stable pedestal for the megaprosthesis body and provide the potential for biologic ingrowth. At 12-month follow-up, she ambulates with a cane, and radiographs reveal stable implant position.

Revision Total Hip Arthroplasty Using a Tibial Cone and Impaction Grafting for Severe Femoral Bone Loss

“…Recently, the novel use of a tibial cone with a PFR in the setting of unfavorable canal geometry was reported 9 . Similar to this case, the previously described case used a tibial cone with a PFR to prevent future stem subsidence, given the patient’s history of rTHA and subsidence into the femoral condyle.…”

“…PFR with IG is also a viable option 7,8 . Moreover, the use of a highly porous tantalum tibial cone with PFR to maximize femoral fixation has been reported 9 . However, outcomes after PFR with IG and a tibial cone for improving fixation in rTHA have not been described.…”

Management of Bone Loss in Revision Total Knee Arthroplasty: An International Consensus Symposium

“…The authors strongly recommend that a cone or sleeve be used, when possible, to enhance stem fixation in hinge prostheses. In the setting of DFR, adjunctive cones have been used; however, clinical outcome and survivorship data are lacking [107]. Currently, cones are designed for augmentation of metaphyseal or metadiaphyseal fixation, rather than for diaphyseal fixation.…”

“…To determine the appropriate stem length for use in segmental hinge replacements and standard condylar hinges without segmental replacement, implant-related factors should be considered, including the ratio of stem length to implant body length (including any segments added in a segmental reconstruction), stem fixation method, and use of a cone or sleeve [3,25,50,72,79,107,141,162]. Patient factors that may be considered include bone quality and body weight or body mass index (BMI).…”

The Use of Metaphyseal Cones and Sleeves in Revision Total Knee Arthroplasty

“…However, there are early reports describing the use of tibial cones with proximal and distal femur replacements to structurally fill the flaring of the femoral canal to serve as a stable pedestal for the megaprosthesis body and provide potential for biologic ingrowth. 43 It should be noted that the utilization of cones with endoprosthesis is currently off-label and further research is warranted to determine its viability.…”