Medium-term outcomes of the S-ROM modular femoral stem in revision hip replacement.

INTRODUCTION: The objective of this study was to analyse results achieved with the S-ROM modular stem in revision surgery.

MATERIALS AND METHODS: A retrospective observational study was conducted from 2007 to 2015 including 51 patients who had a follow-up of ≥ 2 years and complete medical history. The mean age was 66.5 years old (34-87). The main reason for revision was aseptic loosening (38 cases, 74.5%), followed by infection (10, 19.6%), instability (2, 3.9%) and an adverse reaction associated with a metal-on-metal hip implant (1, 2%). Using the Paprosky classification, there were 22 cases of type I (43.1%), 27 of type II (52.9%) and 2 of type IIIA (4%). At the end of the follow-up, radiological parameters were assessed using Engh's criteria. Pre- and postoperative clinical status was assessed using the Harris Hip Score, a visual analogue scale and the Merle D'Aubigné score.

RESULTS: The mean follow-up period was 5.7 years (2-10). The mean Harris Hip Score improved from 45.5 points (22-65) to 85.8 (55-100) (p < 0.001), and the final mean Merle D'Aubigné scores were 5.2, 4.6 and 5.6 for pain, ability to walk and mobility, respectively. Osseointegration was confirmed in all except one patient with fibrous non-union. No aseptic loosening has been recorded. Postoperative complications were deep infection in four cases (7.8%) and dislocation in three (5.9%).

CONCLUSION: This study indicates good medium-term outcomes using a modular hip replacement system with porous-coated proximal sleeves in revision surgery in patients with Paprosky type I and II defects.