Revision hip arthroplasty for femoral stem loosening remains challenging due to significant bone loss and deformities requiring specialized revision stems. The aim of this study was to evaluate the clinical and radiological outcomes, and survival, of a consecutive series of femoral revisions performed using a primary cementless stem with tapered geometry and rectangular cross-section at medium-term follow-up. We retrospectively evaluated 113 patients (115 hips) with intraoperative Paprosky type I (n = 86) or II (n = 29) defects, who underwent femoral revision with Alloclassic Zweymüller SL stem for one-stage aseptic revision or two-stage septic revision from January 2011 to December 2020. The mean follow-up was 77.9 months (SD 33.8). Nine patients were lost to follow-up (deceased or not available), leaving 104 patients (106 hips) for the clinical and radiological analysis. Clinical assessment was performed with Harris Hip Score (HHS) and visual analogue scale (VAS) before surgery and at final follow-up.Aims
Methods
Stem loosening can be associated with a wide spectrum of bone loss and deformity that represent key factors for choosing the most appropriate revision implant. The aim of this study was to evaluate the clinical outcomes and the survivorship of a consecutive series of THA revisions using a taper rectangular cementless stem for primary implants (Alloclassic® Zweymuller®, Zimmer Warsaw US) at medium-term follow-up. We retrospectively evaluated 113 patients (115 revisions) who underwent femoral revision with Zweymuller stem with a preoperative Paprosky I (86) or II (29) defects from January 2011 to December 2020. The mean follow up was 6 years (2–10). The median age at time of surgery was 71(41–93) with 60 males and 53 females. Osteolysis/radiolucency were observed in the following Gruen zones: I (91), II (3), III (2), VII (15), V (3), VI (1). Clinical assessment was performed by means of Harris Hip Score (HHS) and Visual Analogic Scale (VAS), whereas for the radiological analysis we used conventional x-rays of the hips. The statistical analysis was performed using Graphpad Prism v5.0 and data distribution was assessed by Shapiro-Wilk test, and Wilcoxon matched paired test was used to test the differences between preoperative and postoperative score. 9 patients were lost to fu (deceased or not available), 104 (106 hips) were evaluated. The mean HHS and VAS significantly improved at final follow-up, going from 33,84 and 5,78 preoperatively to 66,42 and 2,05 postoperatively, respectively. 28 patients (25%) showed unprogressive radiolucent lines in Gruen zones 1 and 7 with no other radiological nor clinical signs of loosening. One patient suffered from recurrence of the infection. The survivorship with stem revision as endpoint was 100%. Alloclassic Zweymüller primary stem showed good medium-term results and survival rate in revision THA for aseptic loosening and second stages of two stage revisions.
