Radiologic Bone Remodeling Pattern Around DCPD-coated, Metaphyseal-loading Cementless Short Stems in Elderly Patients

Abstract

Concerns exist regarding using short stems during total hip arthroplasties performed in elderly patients. For this study, the authors assessed sequential bone remodeling findings in metaphyseal-loading short stems using serial radiography. A total of 100 consecutive primary THAs using short stems were performed in patients with an average age of 78.3 years. The presence and patterns of radiolucent lines, radiopaque lines, calcar rounding, proximal bone resorption, spot welds, cortical hypertrophy, and intramedullary bone formation around the distal tip were assessed. The final study group comprised 92 hips, and mean follow-up was 60±3 months (range, 48-72 months). At final follow-up, condensations of spot welds were noted in 84 (91.3%) hips. Spot weld formation occurred in all zones except 1 and 4. Calcar rounding was observed in 90 (97.8%) hips. Atrophy of the calcar was noted in 19 (20.6%) hips. Analysis of the proximal zones revealed reactive radiodense lines in zones 1 and 2 (tensile area/shoulder of stem) in 22 (23.9%) hips. A prominent reactive line around the tip of the stem was recorded in 32 (34.8%) hips on radiographs at final follow-up. However, there was no increase in space between the tip of the stem and the radiopaque line. No acetabular or femoral component migrated by more than 1 mm at final follow-up. No acetabular or femoral osteolysis was identified. The radiographic findings of metaphyseal-loading short stems in elderly patients suggest that 91.3% of implants were osseointegrated. No patient required stem revision. Metaphyseal-loading short stems in elderly patients provide continued fixation with adaptive bone remodeling. [PUBLICATION ABSTRACT]