“Conus” Uncemented Stem in Developmental Hip Dysplasia

Abstract

The purpose of this study was to evaluate 115 “Conus” uncemented stems at an average follow-up of 6 years (2–9 years). Seventeen patients were lost at follow-up for a final number of 98 stems in 75 patients. The clinical outcome of 71 hips (72%) was graded excellent, 25 (25%) were good, one (2%) fair and one (2%) poor. The average Harris Hip Score increased from 49.35 before operation to 96.30 at the time of the last follow-up. None of the stems implanted required a revision for aseptic or septic loosening. Cortical hypertrophy or radiolucencies were never seen in any of the stems evaluated. Heterotopic ossification was seen in one hip (1%). Modification of the calcar was observed in 29 hips (30%) and they consisted in a slight rounding off of the proximal medial edge of the cut femoral neck. These results encourage the use of this versatile stem which showed a good primary and secondary stability, with a good load distribution along the femur.