Published online Mar 18, 2024. doi: 10.5312/wjo.v15.i3.257
Peer-review started: November 1, 2023
First decision: November 29, 2023
Revised: December 13, 2023
Accepted: January 16, 2024
Article in press: January 16, 2024
Published online: March 18, 2024
Short stems in total hip arthroplasty are becoming more popular in the younger patient population. The philosophy behind short stems is bone-stock preservation in the proximal femur due to more proximal loading and restoration of the patient’s specific anatomy. As with all new implants on the market, stepwise introduction is needed to avoid a high failure rate in patients. This study contributes to the knowledge of midterm survival data of the Optimys hip stem.
Short hip stems have advantages compared to the widely used conventional stems, especially in the younger and more active patient population. However, long-term survival of the conventional stems is high, so newly introduced implants must have at least a survival rate of 95% at the 10-year follow-up, according to the National Institute for Health and Care Excellence guidelines.
The aim of this study was to determine the mid-term survival of the Optimys hip stem in a large, varied patient population and to assess functional outcomes and quality of life in this patient population. This can show us if the hip stem is an implant that can be commonly used in the daily practice of an orthopedic surgeon. The study can contribute to the fact that this hip stem is safe to implant in a large and varied patient population with an excellent survival rate.
This was a prospective multicenter cohort study conducted in two hospitals in the Netherlands (Amsterdam and Venlo). This gave a large and varied patient population. The primary outcome measure was survival of the hip stem, with revision as the endpoint. Revision was defined as a surgical procedure in which all or part of the previous implanted prosthesis was replaced. Reasons for revision were described. Kaplan-Meier was used for survival rate, by censoring patients at death or at the end of the observation period before 5 years. Log-minus-log transformation was performed to calculate the 95% confidence interval. The secondary outcome measurements included patient-reported outcome measures (PROMs), which consisted of the Hip Disability and Osteoarthritis Outcomes Score, the 36-item Short Form, and a 5-point Likert scale for satisfaction (at 2 years post-surgery). Mixed model analyses were performed to assess the course of the PROMs during the 1st 2 years after surgery. Analyses were modeled separately for the 1st and 2nd years to calculate the yearly change in PROMs during both follow-up periods with accompanying 95% confidence intervals. A P value of < 0.05 was considered statistically significant for all analyses.
The survival rate of the Optimys hip stem at the 5-year follow-up was 98.8% in a group of 500 patients if all revisions were included (n = 6). If infection was left out (n = 3), a survival of 99.4% was seen. The functional outcome and quality of life was significantly improved at the 1-year follow-up and subsequently stabilized at the 2-year follow-up.
Short curved hip stems had a high survival rate at the 5-year follow-up, showing that it is a safe and viable stem for common use in total hip arthroplasty.
Future research includes the long-term follow-up of the Optimys hip stem to determine the survival rate at the 10-year follow-up.