RESUMO
Purpose: Total knee arthroplasty is a common procedure due to increased life expectancy and ageing populations, necessitating implants with long-term efficacy. After some initial designs, the third-generation modular posterior-stabilised NexGen® prosthesis aimed to enhance kinematics and reduce complications. This study evaluates the long-term outcomes, survivorship, revision rates and complications of this implant. With promising results observed up to 15 years in previous studies, this investigation aims to assess the implant's performance over extended follow-up periods, aiding in optimal implant selection for improved patient outcomes. Methods: We carried out a retrospective study on 263 total knee arthroplasties performed in our centre between 1998 and 2002. Statistical analysis of complications was performed and study of survival using the Kaplan-Meier method and competing risk analysis were calculated. Description of reinterventions and complications were also included. Results: Results show a 20-year prosthesis survival rate of 90.8% for revision due to any reason, with an estimated survival of 92.3% considering competitive events. Estimated survivorship at 20 years is 98% for aseptic loosening as the end point, and an estimation of 98.80% considering competitive events. Twenty revisions were performed, with 10 cases due to infection and 10 for noninfectious reasons and three of them due to aseptic loosening. Radiographic analysis revealed radiolucent lines, but no clinical evidence of loosening was observed in these cases. Conclusion: This study offers survivorship data from longer follow-up periods, what is difficult to find in the reported literature and showed excellent results of this implant in terms of survivorship and low rates of revision in our cohort. Level of Evidence: Level IV.
RESUMO
BACKGROUND: The aim of the study is to assess the long-term outcomes of this specific stem (anatomical cementless modular stem ESOP), to review the survivorship, complication rate, and radiographic and clinical outcomes. METHODS: Descriptive and analytical retrospective longitudinal observational study of patients was operated on total hip arthroplasty between 1998 and 2007. Four hundred ninety-six prostheses corresponding to 447 patients were reviewed, mean age was 65.8 years (standard deviation [SD] ±11.6 years), and median follow-up time was 13.4 years (range 1-20). The most used cups were cementless (75.8%). The most frequent friction pairs were metal-polyethylene (53.1%) and ceramic-polyethylene (24.2%). Main variables analyzed were stem survival, subsidence, coronal orientation, osteolysis, reintervention, and Oxford Hip Score. RESULTS: From 496 implants, there were 22 lost to follow-up (4.4%). Stem revision was performed in 51 patients: 26 periprosthetic joint infections (2-stage revision), 16 periprosthetic fractures, and 8 one-stage revisions (6 real aseptic loosening with negative culture after revision). The stem survivorship at more than 15 years for any reason was 89.2% and for aseptic loosening 97.97%. No specific complications were found due to modularity. The mean subsidence and orientation was 2.06 mm (SD ±5.11 mm) and 0.41° varus (SD ±2.20°) respectively. Subsidence >5 mm or varus >5° was associated with a higher revision rate. Osteolysis was found in 110 patients (zone I = 79, VII = 57), associated with zirconium-polyethylene, without relationship to the stem revision rate or Oxford Hip Score. CONCLUSION: To our knowledge, this study represents the largest series of this stem, revealing an excellent survival rate and long-term clinical outcomes similar to the best results of classical cementless stems published in the literature.
