Use of an Electron Beam Melting Manufactured Titanium Collared Cementless Femoral Stem to Resist Subsidence After Canine Total Hip Replacement. Issue 7 (1st July 2015) - Liska, William D.
Abstract Objectives To evaluate the effect of a collared electron beam melting (EBM)‐manufactured titanium cementless femoral stem on implant subsidence after total hip replacement (THR). Study Design Prospective study Animals Dogs (n = 26); 33 THR. Methods Records were maintained on the first 110 consecutive THR using an EBM collared femoral stem. Radiographs on the first 33 THR that had 6‐months follow‐up were evaluated for implant subsidence. These results were compared to 27 dogs with subsidence after THR with a Co Cr collarless stem. Results Dogs that had EBM collared stem THR had a mean body weight of 35.4 kg, body condition score (BCS) of 6.21, and mean canal flare index (CFI) of 1.56. EBM stem sizes used (number implanted) were #7 (13), #8 (10), #9 (8), and #10 (2). Subsidence of collared stems did not occur if the collar was in contact with cortical bone during surgery. Subsidence of 1–3 mm occurred closing a gap between the collar and bone if contact was not made during surgery, but subsidence stopped once contact was made. No major complications directly related to the EBM collared stem were encountered. Conclusions A collar on a cementless femoral stem in contact with cortical bone resists subsidence.