Mid-Term Outcomes of a Modern Zweymüller Monolithic Femoral Stem in Primary Total Hip Arthroplasty

Background: Prosthetic hip replacement is a widely practiced surgical procedure with excellent results. Hip stems based on the Zweymuller design have a long history and their philosophy focuses on achieving long-term stability promoting physiological load transfer. The aim of this study is to evaluate outcomes, survivorship, and complication rates in a cohort of patients treated with this stem. Methods: A retrospective review was conducted to identify patients who underwent primary THA with Zweymuller stems. A total of 86 hips (43%) were implanted in men, and 114 hips (57%) in women. The mean follow-up time was 5.4 years. Patient charts were reviewed for adverse events occurring after primary THA as well as for revision and indication for revision. Patients still implanted with the hip stem were asked to complete the HOOS JR survey. Results: Ten hips (5.0%) were lost to follow up. The mean HOOS JR score at final evaluation was 96.3 points (range, 60.0-100.0). Two revisions were performed during the study for femoral stem loosening due to a periprosthetic Vancouver B2 fracture and for multiple hip dislocations. Conclusions: The Zweymuller design hip stem showed excellent survivorship and favorable clinical outcomes at a mean follow-up of 5.4 years.