Early results of a conservative hip stem

Introduction: Different conservative stems are available for primary cementless total hip arthroplasty (THA). The aim of this preliminary study is to assess short-term results of the GTS femoral stem (Biomet) for THA. Patients and methods: For this retrospective study of prospectively collected data, 40 patients (28 males, 12 females) who received a THA with a GTS femoral stem from 2011 to 2013 were evaluated. The mean age at the time of surgery was 48.5 years (range 31-81). All patients were operated by one surgeon with a postero-lateral approach. Etiology: 30 osteoarthritis (19 primary, 6 post-traumatic, 5 post-dysplastic) and 10 AVN of the femoral head. A press-fit hemispheric titanium acetabular component was used in all cases. Tribology: 32 ceramic on polyethylene, 8 metal on polyethylene. The mean follow-up was 26.3 month (range 15-40 months). All patients were assessed preoperatively and at the last follow-up with two patient-oriented instruments, the Harris Hip score (HHS) and WOMAC questionnaires. As a part of routine care, radiographs were obtained preoperatively and at set intervals (One day postoperative, 6 months postoperatively, 1 year postoperatively, and annually thereafter) and evaluated for any radiolucencies or osteolysis in Gruen zones, heterotopic ossifications (Brooker scale), and stem subsidence. Results: The mean HHS increased from 44 points (range 17-61) before surgery to 91.3 points (range 82-99.7) at the last follow-up (P<0.001). The disability according to mean WOMAC Score decreased from 61.8 before surgery (range 32-100) to 9.2 (range 0-47) at the final follow-up (P<0.001). Thirty-eight patients (95%) were fully satisfied with their result. The radiographic analysis at the last follow-up showed non-significant radiolucencies (less than 1 mm of width) in 3 cases (2 Gruen zone 1 and 1 in Gruen zone 5). Heterotopic ossification was present in 1 hip (Brooker 1). No stem showed subsidence of more than 5 mm at the time of final follow-up. No implant-related complication was diagnosed in this series. No implant showed radiographic loosening or was revised for any reason. Conclusions: Short term subjective clinical outcomes and radiographic results of the GTS femoral stem are excellent and comparable with published data for contemporary cementless stems. The level of post-surgical satisfaction was high in this study group.