Short-term Outcomes of Impaction Bone Grafting Technique with a Collared Fully Hydroxyapatite-Coated Stem in Revision Total Hip Arthroplasty: A Case Series.

INTRODUCTION: Impaction bone grafting (IBG) with cemented stems in revision total hip arthroplasty (THA) is a well-established method, but reports using cementless stems are scarce. The purpose of this study is to report short-term outcomes of six revision THAs using the IBG technique with a collared fully hydroxyapatite (HA)-coated stem. MATERIALS AND METHODS: From 2014 to 2021, six joints (median age 64.3 years; median follow-up 4.5 years) were revised for aseptic loosening (n = 5) or septic loosening (n = 1). All cases used the IBG technique with a collared fully HA-coated stem (CORAIL or UNIVERSIA). Full weight-bearing was allowed post-operative day 1. Outcomes included the Japanese Orthopedic Association Score, stem subsidence, and radiographic remodeling. RESULTS: Median surgical time was 127 min; blood loss was 855 mL. No complications (infection, polyethylene wear, loosening, or dislocation) occurred. The JOA score improved from 63 (preoperatively) to 95 (final follow-up). Median stem subsidence was 1.4 mm (1-3 mm), with no case >5 mm. Radiographs showed no radiolucent lines and remodeling in all cases. Computed tomography (CT) images of one case confirmed bone ingrowth between the stem and the compressed allograft. CONCLUSION: Short-term outcomes of revision THA with IBG using a collared fully HA-coated stem are favorable. This technique, supported by radiographic and CT evidence of bone ingrowth, is a useful and effective treatment option for femoral component revision.