Stability Differentials for Proximal vs Distal Fusion of Total Hip Arthroplasty Femoral Impaction Grafts

Abstract

In impaction grafting for revision joint arthroplasty, the morselized cancellous bone (MCB) ideally remodels into a new contiguous lattice. However, the use of biologically active factors may sometimes be indicated to enhance fusion. The purpose of this study was to determine the stability of femoral impaction graft constructs for which either only the proximal or distal half of the MCB volume was modeled as fused. Fusing the proximal half of the impaction graft volume resulted in a higher femoral stem stability than did fusing the distal half. This proximal graft fusion also resulted in a stem stability that was similar to that of fusing the entire graft. These results emphasize the importance of proximal fixation of an impaction grafted femoral stem.

Characterization of Femoral Component Initial Stability and Cortical Strain in a Reduced Stem-Length Design

“…Investigations in the primary stability of THA femoral components have utilized bench 246 testing in cadaveric [23,24,25,31,32] and composite [18,[33][34][35][36][37][38] femur specimens, as 247 well as finite element analysis [23,24,34,39,40] in reporting a wide range of stability 248 data, dependent on measurement techniques, loading profiles, and setup design. Prior in 249 vitro THA micromotion studies have primarily used linear variable differential 250 transformer (LVDT) or differential variable reluctance transducer (DVRT) sensors to 251 quantify implant stability: instrumentation which typically require complex 252 instrumentation to be rigidly fixed to the specimens and allow for displacement 253 measurements at a single point in space [31, 33-37, 40-43, 48].…”