Femoral neck preservation with a short hip stem produced with powder manufacturing: mid-term results of a consecutive case series.

Stress shielding and thigh pain are not uncommon after cementless total hip arthroplasty (THA) using conventional hip stems. It has been postulated that short, neck-preserving stems may overcome these disadvantages of standard stems and, hence, further improve clinical outcome. The purpose of our retrospective study was to assess the mid-term performance of a neck-preserving hip stem for which, as of yet, no clinical results have been published. A population of 146 consecutive patients who received 152 neck-preserving stems over a 1.6-year period was retrospectively reviewed. Harris Hip Score (HHS) and the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) were collected, along with radiographic data. One hundred and forty-four THAs implanted in 136 patients were available for analysis. After a mean follow-up of 56 months, mean HHS and WOMAC improved significantly versus preoperative values. Aseptic loosening was not observed. Five-year survival with revision of any component for any reason as the endpoint was 99.3% (95% confidence interval, 95.2-99.9%). Excellent mid-term clinical and radiographic outcomes were observed with the study device. We attribute this to the metaphyseal fit in combination with retention of the femoral neck. However, our findings need to be confirmed by multicentre studies with larger patient samples.