(P 481) CUSTOM ADAPTERS FOR COMPRESS SPINDLE OSSEOINTEGRATION FIXATION IN REVISION LIMB SALVAGE SURGERY OF THE DISTAL FEMUR: A CASE SERIES

Objective: Revision surgery is not uncommon following distal femur limb salvage with endoprosthetic replacement (EPR). In many instances, mechanical failure is limited to the femur with preserved well-fixed tibial components. Compressive osseointegration devices allow for biologic ingrowth and theoretical greater preservation of remaining bone stock compared to stemmed arthroplasty, but issues with implant compatibility frequently necessitate revision of both femoral and tibial components. Custom adapters to link this technology with EPRs from another implant company may decrease risk for further bone loss and intraoperative complication risk by eliminating the need for tibial revision. This is a case series of three patients undergoing revision utilizing a custom adapter.

Methods: Three patients (mean age 39.1±14.4 years; 3F) underwent revision for aseptic loosening (2) or implant breakage (1) with a custom adapter linking compressive osseointegration fixation to an EPR of a different system. Radiographic and clinical outcomes were assessed at three years minimum follow-up.

Results: Mean times to FDA approval (9 days), and implant manufacturing (29 days) was similar among patients. Hypertrophic bone ingrowth was seen in 3/3 patients, with no implant failure at mean 68 months follow-up.

Conclusion: All patients in this series treated with a custom adapter experienced sustained bone ingrowth with compressive osseointegration, no implant failure, and no need for tibial stem revision at minimum three-year follow-up. Overall time required for implant approval and manufacturing was 9 days and 29 days, respectively.