Computer-Navigated versus Conventional Total Knee Arthroplasty: No Difference in Implant Survival at 15-Year Follow-Up

Computer-Navigated versus Conventional Total Knee Arthroplasty: No Difference in Implant Survival at 15-Year Follow-Up | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Computer-Navigated versus Conventional Total Knee Arthroplasty: No Difference in Implant Survival at 15-Year Follow-Up Giovanni Longo, Giacomo Pacchiarotti, Carmela Pizzigallo, Stefano Gumina, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8196906/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction: The introduction of computer-assisted navigation (CAS) in total knee arthroplasty (TKA) aimed to improve prosthetic alignment and potentially enhance long-term implant survival. However, the actual clinical benefit beyond 10 years remains debated. Materials and Methods: Prospective comparative non-randomized study with a mean follow-up of 15.4 years, including patients undergoing TKA using either a conventional (CONV) or computer-navigated (NAV) technique. The primary outcome was implant survival (absence of revision for any cause). Secondary outcomes were functional scores: Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: Fifteen-year implant survival was 70.5% (CONV) vs 73.4% (NAV) (p > 0.05). No statistically significant differences were found in functional outcomes. Mortality unrelated to the prosthesis was high in both groups. Conclusions: At 15 years, the navigated technique did not demonstrate significant advantages over the conventional approach in terms of implant survival or functional outcomes. Larger prospective studies are required to confirm these findings. total knee arthroplasty computer-assisted surgery navigation implant survival long-term follow-up Figures Figure 1 Introduction Total knee arthroplasty (TKA) is one of the most frequently performed major orthopedic procedures, with increasing volume driven by population aging and the expansion of indications. The primary goal remains pain reduction and functional recovery, but in recent decades interest has grown in the relationship between alignment accuracy, component positioning, and long-term implant survival [ 1 – 4 ]. The traditional concept of neutral mechanical alignment (± 3°) originated from historical studies suggesting an association with greater implant longevity [ 2 , 4 ], although subsequent work has downplayed the centrality of this single parameter, emphasizing the multifactorial nature of long-term outcomes (implant design, surgical technique, soft-tissue balancing) [ 5 – 7 ]. There is no evidence demonstrating the superiority of mechanical alignment in terms of clinical or functional outcomes; the available literature rather shows a possible correlation between correct mechanical alignment and implant longevity, but not with improved patient-reported outcome measures [ 8 – 11 ]. Computer-assisted surgery (CAS) was introduced to increase intraoperative precision and reduce inter-operator variability. Navigation has proven to be a useful adjunct, particularly during the early learning curve, improving the accuracy of bone resections and reproducibility of results even for less-experienced surgeons. Randomized trials and observational studies have demonstrated a reduction in radiographic outliers and greater reproducibility of component positioning with CAS in the short term [ 5 , 6 , 11 – 13 ]. However, the translation of this improved accuracy into tangible clinical benefits and lower revision rates remains controversial: some series and registry studies have reported advantages in younger patients or specific subgroups [ 12 , 14 – 17 ], whereas others, including randomized trials with follow-up beyond 10 years, have found no significant differences compared with conventional techniques [ 13 – 16 , 18 , 19 ]. In Italy, as in other European contexts, the adoption of CAS has been influenced by economic, organizational, and learning-curve considerations [ 20 – 23 ]. Interest has now shifted toward robot-assisted approaches and patient-specific implantation strategies. In this study, we report a mean follow-up of 15.4 years comparing conventional and navigated techniques in terms of implant survival (revision for any cause) and clinical–functional outcomes (KSS, WOMAC). This work aims to contribute to the discussion on the true long-term clinical value of CAS, integrating local experience with international evidence. Materials and Methods This was a long-term, retrospective comparative analysis. All patients who underwent primary total knee arthroplasty (TKA) between 2005 and 2006 at our Institution were included. All implants were the same cemented, mobile-bearing, ultra-congruent model (SCORE Primary Arthroplasty, Amplitude, Valence, France). Procedures were performed by a single experienced surgeon using either the conventional (CONV) or computer-navigated (NAV) technique. All TKAs were performed with a ligament-referencing technique through a standard medial parapatellar approach. The inclusion criteria comprised patients aged 60 years or older at the time of surgery, with a diagnosis of primary knee osteoarthritis. Individuals with post-traumatic osteoarthritis, rheumatoid arthritis, or a history of major knee surgery were excluded, as were those presenting with extra-articular deformities requiring corrective osteotomies. Only patients with a minimum clinical follow-up of 15 years were eligible for final analysis. Exclusion criteria included revision total knee arthroplasty, severe systemic conditions that prevented functional assessment, and comorbidities that markedly limited independent ambulation. All procedures were followed by a standardized postoperative rehabilitation protocol consisting of early active and passive mobilization, full weight bearing with assistive devices from postoperative day one, and structured physiotherapy until the recovery of functional range of motion and an independent gait pattern. The minimum required follow-up for inclusion in the study was 15 years. The primary outcomes were implant survival at 15 years—defined as the absence of revision of any prosthetic component—and all-cause mortality unrelated to the knee implant. Secondary outcomes included functional evaluation using the Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), performed in all available patients during in-person clinical assessment. Cases excluded from functional evaluation due to severe comorbidities, loss to follow-up, or non-response were documented. Ethical approval According to our institutional regulations, ethical approval was not required for this retrospective study, as it involved the analysis of fully anonymized data collected during routine clinical practice and did not include any intervention beyond standard care. This study was conducted in accordance with the 1964 Helsinki Declaration and its later amendments. Statistical Analysis Statistical analysis was performed using SPSS software (IBM Corp., Armonk, NY, USA). Continuous variables were expressed as mean ± standard deviation (SD) and compared between groups using the Student’s t -test for independent samples. Categorical variables were presented as counts and percentages and analyzed using the chi-square test or Fisher’s exact test, as appropriate. Implant survival was evaluated using Kaplan–Meier survival analysis, and intergroup differences were assessed with the log-rank test. A p -value < 0.05 was considered statistically significant. Results The initial study cohort comprised 240 consecutive primary total knee arthroplasties (TKAs), evenly distributed between the two groups: 120 conventional (CONV) and 120 computer-assisted (NAV) procedures. The mean age at surgery was comparable between groups, being 78.8 ± 7.2 years (range 60–95) in the CONV group and 79.1 ± 7.4 years (range 60–94) in the NAV group ( p = ns). The sex distribution was similar, with a clear predominance of females (69.2% and 70.0%, respectively). The mean follow-up was identical for both cohorts at 15.4 years (range 15–16). No statistically significant differences were found in any baseline demographic variable (Table 1). At the final follow-up, implant survival was 70.5% for CONV and 73.4% for NAV ( p = ns), indicating no significant difference in long-term prosthetic endurance between the two surgical techniques. A total of seven revisions were performed throughout the study period: four in the CONV group (two late infections, one acute infection, and one aseptic loosening) and three in the NAV group (one aseptic loosening, one multidirectional instability following a stroke, and one periprosthetic fracture). Non–implant-related mortality was substantial, reflecting the advanced age and frailty of the population: 49 patients (40.8%) in the CONV group and 57 patients (47.5%) in the NAV group had died from causes unrelated to the implant at the time of final assessment. At final evaluation, clinical and functional data were available for 40 CONV and 35 NAV patients. All surviving patients underwent direct assessment, either through a clinical visit (23 CONV, 17 NAV) or structured telephone interview (17 CONV, 18 NAV). Functional outcomes were comparable between the two cohorts. The mean Knee Society Score (KSS) was 170.8 ± 14.2 (range 138–198) for CONV and 172.1 ± 13.7 (range 142–198) for NAV ( p = 0.46). Similarly, the mean WOMAC score was 20.4 ± 11.9 (range 0–47) in the CONV group and 18.7 ± 10.5 (range 0–44) in the NAV group ( p = 0.38). No statistically significant differences were observed for either outcome measure, indicating that computer-assisted surgery did not provide measurable clinical or functional advantages in this long-term follow-up population (Table 2). The Kaplan–Meier analysis demonstrated nearly overlapping survival curves for conventional and navigated TKA throughout the 15-year follow-up, with a very low number of revision events and no statistically significant differences between groups (Fig. 1). Table 1. Demographic and baseline data of the patients Variable CONV (n = 120) NAV (n = 120) p-value Mean age ± SD (years) 78.8 ± 7.2 79.1 ± 7.4 ns Age range (years) 60–95 60–94 – Female sex (%) 69.2 70.0 ns Mean follow-up (years) 15.4 (15–16) 15.4 (15–16) ns *ns: not significant.* Table 2. Clinical and survival outcomes Variable CONV (n = 120) NAV (n = 120) p-value Implant survival (%) 70.5 73.4 ns Total revisions (n) 4 3 – Late infection 2 0 – Acute infection 1 0 – Aseptic loosening 1 1 – Multidirectional instability 0 1 – Periprosthetic fracture 0 1 – Unrelated deaths (n) 49 57 – Clinical–functional evaluation (n) 40 35 – Clinical visit 23 17 – Telephone interview 17 18 – Mean KSS ± SD (range) 170.8 ± 14.2 (138–198) 172.1 ± 13.7 (142–198) 0.46 Mean WOMAC ± SD (range) 20.4 ± 11.9 (0–47) 18.7 ± 10.5 (0–44) 0.38 *ns: not significant; KSS: Knee Society Score; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index* Discussion Clinical and functional outcomes assessed using the Knee Society Score (KSS) and WOMAC showed no statistically significant differences between groups. However, the interpretation of these results must consider the characteristics of the surviving cohort: the mean age at final evaluation exceeded 90 years, and many patients were deceased or unreachable. Consequently, the number of individuals available for functional assessment was markedly reduced, likely limiting statistical power and increasing the risk of type II error. This demographic shift highlights an important temporal evolution in TKA indications. At the time the index surgeries were performed, total knee arthroplasty was reserved for end-stage osteoarthritis in elderly, low-demand patients, largely due to concerns regarding implant durability and early failure. In recent years, however, the advancement of implant design, biomaterials, and surgical precision has substantially improved long-term outcomes. Surgeons are therefore increasingly inclined to offer TKA to younger and more active patients, confident in the enhanced survivorship of modern prostheses. Consequently, contemporary series often involve a different patient profile, introducing a selection bias when comparing long-term results from historical cohorts with those of current practice. The high mean age and mortality observed in the present study reflect this older generation of TKA recipients and inevitably limit the generalizability of the functional comparison. Nevertheless, within this aged cohort, true mechanical or septic failures were rare, and the revision rate remained remarkably low, supporting the long-term reliability of both surgical techniques. This study, with a mean follow-up of 15.4 years, represents one of the longest analyses available comparing conventional and navigated TKA. The results showed no significant differences in either implant survival or functional outcomes. This finding aligns with several long-term publications reporting similar results [6,12–17,19]. For instance, Parratte et al. [4], in a 15-year prospective study, reported no significant association between mechanical alignment and implant survival. Similarly, Cip et al. [12] found comparable survival rates between computer-assisted and conventional techniques, although alignment accuracy was superior in the navigated group. In contrast, Baumbach et al. [14] demonstrated a survival advantage for computer-assisted surgery, particularly in younger patients, suggesting that its benefits may become evident only in specific subpopulations. The absence of differences in our results may be attributable to several factors: (1) the high surgical experience of the team, which may minimize the gap between the two techniques; (2) the advanced age of the population, limiting observation of failures due to wear or malalignment; (3) the definition of revision used, which excluded minor re-interventions; and (4) loss to follow-up, which could have reduced statistical power. From a clinical perspective, these results suggest that the choice between CAS and the conventional technique should consider not only intraoperative accuracy but also resource availability, patient profile, and surgeon preference. Future perspectives include the further evolution toward robot-assisted systems and adoption of personalized implants, which may provide functional benefits yet to be demonstrated in long-term studies. Strengths of this work include the exceptionally long follow-up and analysis of a homogeneous population operated on in the same period by the same surgical team. Limitations include loss to follow-up and the absence of randomization. In conclusion, our results contribute to the growing body of evidence suggesting that, in the experienced surgeon, CAS does not lead to significant clinical differences compared with the conventional technique, while retaining an important role in training and procedural standardization. Although clinical outcomes in experienced surgeons do not differ significantly between conventional and navigated techniques—since both pursue similar mechanical alignment—CAS has introduced a conceptual shift: the quantification and measurement of the surgical act. Quantitative control of bone resections and joint balancing has progressively replaced reliance solely on tactile perception, paving the way for the development of robot-assisted surgery. The latter, combining mechanical precision with prosthetic personalization, may in the future demonstrate more tangible clinical advantages. Conclusion At 15 years of follow-up, computer-navigated TKA did not show significant advantages over the conventional technique in terms of implant survival or functional outcomes. Larger, prospective, and multicenter studies are warranted to confirm these results and to further clarify the evolving role of navigation within the context of robotic and personalized knee arthroplasty. Declarations Ethics statement The study involving human participants was approved by the Institutional Review Board of the Istituto Chirurgico Ortopedico Traumatologico (ICOT), Latina, Italy (protocol number 14/2008). All participants provided written informed consent. Ethical Approval According to our institutional regulations, ethical approval was not required for this retrospective study, as it involved the analysis of fully anonymized data collected during routine clinical practice and did not include any intervention beyond standard care. This study was conducted in accordance with the 1964 Helsinki Declaration and its later amendments. Informed Consent Informed consent was obtained from all patients who were successfully contacted for the study. Funding The authors received no funding for this research. Competing Interests The authors declare that they have no competing interests. Availability of Data The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request. Authors' Contributions Study conception and design: Pachiarotti, Longo Data collection and analysis: Longo, Pizzigallo Manuscript drafting: Longo Manuscript revision: Todesca, Gumina References Rand JA, Coventry MB. Ten-year evaluation of geometric total knee arthroplasty. Clin Orthop Relat Res. 1988;(232):168–173. Ritter MA, Faris PM, Keating EM, Meding JB. Postoperative alignment of total knee replacement. Clin Orthop Relat Res. 1994;(299):153–156. Bonner TJ, Eardley WGP, Patterson P, Gregg PJ. Effect of postoperative mechanical axis alignment on survival of primary total knee replacement. J Bone Joint Surg Br. 2011;93:1217–1222. Parratte S, Pagnano MW, Trousdale RT, Berry DJ. Effect of mechanical axis alignment on 15-year survival. J Bone Joint Surg Am. 2010;92(12):2143–2149. Martin A, Wohlgenannt O, Prenn M, et al. 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EFORT Open Rev. 2021;6(3):238–247. Sarpong NO, Geller JA, Cooper HJ, Shah RP, Chen AF. What is the learning curve for new technologies in total joint arthroplasty? Clin Orthop Relat Res. 2020;478(12):2799–2809. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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1","display":"","copyAsset":false,"role":"figure","size":131156,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan–Meier curves illustrating implant survival over 15 years in conventional and navigated TKA; survival patterns are nearly overlapping, with very few revision events and no statistically significant difference between groups\u003c/p\u003e","description":"","filename":"Figure1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8196906/v1/85adec83cc131a81390d28e7.jpeg"},{"id":97677256,"identity":"ed18420f-8b1e-47d4-aa4c-30243bbad956","added_by":"auto","created_at":"2025-12-08 09:52:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":572913,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8196906/v1/03462987-2193-412e-871d-9b59cc8c830b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Computer-Navigated versus Conventional Total Knee Arthroplasty: No Difference in Implant Survival at 15-Year Follow-Up","fulltext":[{"header":"Introduction","content":"\u003cp\u003eTotal knee arthroplasty (TKA) is one of the most frequently performed major orthopedic procedures, with increasing volume driven by population aging and the expansion of indications. The primary goal remains pain reduction and functional recovery, but in recent decades interest has grown in the relationship between alignment accuracy, component positioning, and long-term implant survival [\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe traditional concept of neutral mechanical alignment (\u0026plusmn;\u0026thinsp;3\u0026deg;) originated from historical studies suggesting an association with greater implant longevity [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], although subsequent work has downplayed the centrality of this single parameter, emphasizing the multifactorial nature of long-term outcomes (implant design, surgical technique, soft-tissue balancing) [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThere is no evidence demonstrating the superiority of mechanical alignment in terms of clinical or functional outcomes; the available literature rather shows a possible correlation between correct mechanical alignment and implant longevity, but not with improved patient-reported outcome measures [\u003cspan additionalcitationids=\"CR9 CR10\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eComputer-assisted surgery (CAS) was introduced to increase intraoperative precision and reduce inter-operator variability. Navigation has proven to be a useful adjunct, particularly during the early learning curve, improving the accuracy of bone resections and reproducibility of results even for less-experienced surgeons.\u003c/p\u003e\u003cp\u003eRandomized trials and observational studies have demonstrated a reduction in radiographic outliers and greater reproducibility of component positioning with CAS in the short term [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eHowever, the translation of this improved accuracy into tangible clinical benefits and lower revision rates remains controversial: some series and registry studies have reported advantages in younger patients or specific subgroups [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan additionalcitationids=\"CR15 CR16\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], whereas others, including randomized trials with follow-up beyond 10 years, have found no significant differences compared with conventional techniques [\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn Italy, as in other European contexts, the adoption of CAS has been influenced by economic, organizational, and learning-curve considerations [\u003cspan additionalcitationids=\"CR21 CR22\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eInterest has now shifted toward robot-assisted approaches and patient-specific implantation strategies.\u003c/p\u003e\u003cp\u003eIn this study, we report a mean follow-up of 15.4 years comparing conventional and navigated techniques in terms of implant survival (revision for any cause) and clinical\u0026ndash;functional outcomes (KSS, WOMAC). This work aims to contribute to the discussion on the true long-term clinical value of CAS, integrating local experience with international evidence.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eThis was a long-term, retrospective comparative analysis. All patients who underwent primary total knee arthroplasty (TKA) between 2005 and 2006 at our Institution were included. All implants were the same cemented, mobile-bearing, ultra-congruent model (SCORE Primary Arthroplasty, Amplitude, Valence, France). Procedures were performed by a single experienced surgeon using either the conventional (CONV) or computer-navigated (NAV) technique.\u003c/p\u003e\n\u003cp\u003eAll TKAs were performed with a ligament-referencing technique through a standard medial parapatellar approach.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe inclusion criteria comprised patients aged 60 years or older at the time of surgery, with a diagnosis of primary knee osteoarthritis. Individuals with post-traumatic osteoarthritis, rheumatoid arthritis, or a history of major knee surgery were excluded, as were those presenting with extra-articular deformities requiring corrective osteotomies. Only patients with a minimum clinical follow-up of 15 years were eligible for final analysis.\u003c/p\u003e\n\u003cp\u003eExclusion criteria included revision total knee arthroplasty, severe systemic conditions that prevented functional assessment, and comorbidities that markedly limited independent ambulation.\u003c/p\u003e\n\u003cp\u003eAll procedures were followed by a standardized postoperative rehabilitation protocol consisting of early active and passive mobilization, full weight bearing with assistive devices from postoperative day one, and structured physiotherapy until the recovery of functional range of motion and an independent gait pattern. The minimum required follow-up for inclusion in the study was 15 years.\u003c/p\u003e\n\u003cp\u003eThe primary outcomes were implant survival at 15 years\u0026mdash;defined as the absence of revision of any prosthetic component\u0026mdash;and all-cause mortality unrelated to the knee implant. Secondary outcomes included functional evaluation using the Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), performed in all available patients during in-person clinical assessment. Cases excluded from functional evaluation due to severe comorbidities, loss to follow-up, or non-response were documented.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003cbr\u003e\u003c/strong\u003eAccording to our institutional regulations, ethical approval was not required for this retrospective study, as it involved the analysis of fully anonymized data collected during routine clinical practice and did not include any intervention beyond standard care. This study was conducted in accordance with the 1964 Helsinki Declaration and its later amendments.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analysis was performed using SPSS software (IBM Corp., Armonk, NY, USA).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eContinuous variables were expressed as mean \u0026plusmn; standard deviation (SD) and compared between groups using the Student\u0026rsquo;s\u0026nbsp;\u003cem\u003et\u003c/em\u003e-test for independent samples. Categorical variables were presented as counts and percentages and analyzed using the chi-square test or Fisher\u0026rsquo;s exact test, as appropriate.\u003cbr\u003e\u0026nbsp;Implant survival was evaluated using Kaplan\u0026ndash;Meier survival analysis, and intergroup differences were assessed with the log-rank test.\u003cbr\u003eA \u003cem\u003ep\u003c/em\u003e-value \u0026lt; 0.05 was considered statistically significant.\u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe initial study cohort comprised 240 consecutive primary total knee arthroplasties (TKAs), evenly distributed between the two groups: 120 conventional (CONV) and 120 computer-assisted (NAV) procedures.\u003cbr\u003eThe mean age at surgery was comparable between groups, being 78.8 \u0026plusmn; 7.2 years (range 60\u0026ndash;95) in the CONV group and 79.1 \u0026plusmn; 7.4 years (range 60\u0026ndash;94) in the NAV group (\u003cem\u003ep\u003c/em\u003e = ns). The sex distribution was similar, with a clear predominance of females (69.2% and 70.0%, respectively). The mean follow-up was identical for both cohorts at 15.4 years (range 15\u0026ndash;16). No statistically significant differences were found in any baseline demographic variable (Table 1).\u003c/p\u003e\n\u003cp\u003eAt the final follow-up, implant survival was 70.5% for CONV and 73.4% for NAV (\u003cem\u003ep\u003c/em\u003e = ns), indicating no significant difference in long-term prosthetic endurance between the two surgical techniques. A total of seven revisions were performed throughout the study period: four in the CONV group (two late infections, one acute infection, and one aseptic loosening) and three in the NAV group (one aseptic loosening, one multidirectional instability following a stroke, and one periprosthetic fracture).\u003c/p\u003e\n\u003cp\u003eNon\u0026ndash;implant-related mortality was substantial, reflecting the advanced age and frailty of the population: 49 patients (40.8%) in the CONV group and 57 patients (47.5%) in the NAV group had died from causes unrelated to the implant at the time of final assessment.\u003c/p\u003e\n\u003cp\u003eAt final evaluation, clinical and functional data were available for 40 CONV and 35 NAV patients. All surviving patients underwent direct assessment, either through a clinical visit (23 CONV, 17 NAV) or structured telephone interview (17 CONV, 18 NAV).\u003cbr\u003eFunctional outcomes were comparable between the two cohorts. The mean Knee Society Score (KSS) was 170.8 \u0026plusmn; 14.2 (range 138\u0026ndash;198) for CONV and 172.1 \u0026plusmn; 13.7 (range 142\u0026ndash;198) for NAV (\u003cem\u003ep\u003c/em\u003e = 0.46). Similarly, the mean WOMAC score was 20.4 \u0026plusmn; 11.9 (range 0\u0026ndash;47) in the CONV group and 18.7 \u0026plusmn; 10.5 (range 0\u0026ndash;44) in the NAV group (\u003cem\u003ep\u003c/em\u003e = 0.38). No statistically significant differences were observed for either outcome measure, indicating that computer-assisted surgery did not provide measurable clinical or functional advantages in this long-term follow-up population (Table 2).\u003c/p\u003e\n\u003cp\u003eThe Kaplan\u0026ndash;Meier analysis demonstrated nearly overlapping survival curves for conventional and navigated TKA throughout the 15-year follow-up, with a very low number of revision events and no statistically significant differences between groups (Fig. 1).\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 1. Demographic and baseline data of the patients\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 164px;\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003eCONV (n = 120)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003eNAV (n = 120)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 164px;\"\u003e\n \u003cp\u003eMean age \u0026plusmn; SD (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e78.8 \u0026plusmn; 7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e79.1 \u0026plusmn; 7.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 164px;\"\u003e\n \u003cp\u003eAge range (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e60\u0026ndash;95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e60\u0026ndash;94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 164px;\"\u003e\n \u003cp\u003eFemale sex (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e69.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e70.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 164px;\"\u003e\n \u003cp\u003eMean follow-up (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e15.4 (15\u0026ndash;16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e15.4 (15\u0026ndash;16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e*ns: not significant.*\u003cstrong\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 2. Clinical and survival outcomes\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"663\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003eCONV (n = 120)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003eNAV (n = 120)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eImplant survival (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e70.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e73.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eTotal revisions (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eLate infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eAcute infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eAseptic loosening\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eMultidirectional instability\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003ePeriprosthetic fracture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eUnrelated deaths (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eClinical\u0026ndash;functional evaluation (n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eClinical visit\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eTelephone interview\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e\u0026ndash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eMean KSS \u0026plusmn; SD (range)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e170.8 \u0026plusmn; 14.2 (138\u0026ndash;198)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e172.1 \u0026plusmn; 13.7 (142\u0026ndash;198)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e0.46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 222px;\"\u003e\n \u003cp\u003eMean WOMAC \u0026plusmn; SD (range)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e20.4 \u0026plusmn; 11.9 (0\u0026ndash;47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e18.7 \u0026plusmn; 10.5 (0\u0026ndash;44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 147px;\"\u003e\n \u003cp\u003e0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e*ns: not significant; KSS: Knee Society Score; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index*\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eClinical and functional outcomes assessed using the Knee Society Score (KSS) and WOMAC showed no statistically significant differences between groups. However, the interpretation of these results must consider the characteristics of the surviving cohort: the mean age at final evaluation exceeded 90 years, and many patients were deceased or unreachable. Consequently, the number of individuals available for functional assessment was markedly reduced, likely limiting statistical power and increasing the risk of type II error.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis demographic shift highlights an important temporal evolution in TKA indications. At the time the index surgeries were performed, total knee arthroplasty was reserved for end-stage osteoarthritis in elderly, low-demand patients, largely due to concerns regarding implant durability and early failure. In recent years, however, the advancement of implant design, biomaterials, and surgical precision has substantially improved long-term outcomes. Surgeons are therefore increasingly inclined to offer TKA to younger and more active patients, confident in the enhanced survivorship of modern prostheses.\u003c/p\u003e\n\u003cp\u003eConsequently, contemporary series often involve a different patient profile, introducing a selection bias when comparing long-term results from historical cohorts with those of current practice. The high mean age and mortality observed in the present study reflect this older generation of TKA recipients and inevitably limit the generalizability of the functional comparison. Nevertheless, within this aged cohort, true mechanical or septic failures were rare, and the revision rate remained remarkably low, supporting the long-term reliability of both surgical techniques.\u003c/p\u003e\n\u003cp\u003eThis study, with a mean follow-up of 15.4 years, represents one of the longest analyses available comparing conventional and navigated TKA. The results showed no significant differences in either implant survival or functional outcomes. This finding aligns with several long-term publications reporting similar results [6,12\u0026ndash;17,19].\u003c/p\u003e\n\u003cp\u003eFor instance, Parratte et al. [4], in a 15-year prospective study, reported no significant association between mechanical alignment and implant survival. Similarly, Cip et al. [12] found comparable survival rates between computer-assisted and conventional techniques, although alignment accuracy was superior in the navigated group. In contrast, Baumbach et al. [14] demonstrated a survival advantage for computer-assisted surgery, particularly in younger patients, suggesting that its benefits may become evident only in specific subpopulations.\u003c/p\u003e\n\u003cp\u003eThe absence of differences in our results may be attributable to several factors: (1) the high surgical experience of the team, which may minimize the gap between the two techniques; (2) the advanced age of the population, limiting observation of failures due to wear or malalignment; (3) the definition of revision used, which excluded minor re-interventions; and (4) loss to follow-up, which could have reduced statistical power.\u003c/p\u003e\n\u003cp\u003eFrom a clinical perspective, these results suggest that the choice between CAS and the conventional technique should consider not only intraoperative accuracy but also resource availability, patient profile, and surgeon preference. Future perspectives include the further evolution toward robot-assisted systems and adoption of personalized implants, which may provide functional benefits yet to be demonstrated in long-term studies.\u003c/p\u003e\n\u003cp\u003eStrengths of this work include the exceptionally long follow-up and analysis of a homogeneous population operated on in the same period by the same surgical team. Limitations include loss to follow-up and the absence of randomization.\u003c/p\u003e\n\u003cp\u003eIn conclusion, our results contribute to the growing body of evidence suggesting that, in the experienced surgeon, CAS does not lead to significant clinical differences compared with the conventional technique, while retaining an important role in training and procedural standardization.\u003c/p\u003e\n\u003cp\u003eAlthough clinical outcomes in experienced surgeons do not differ significantly between conventional and navigated techniques\u0026mdash;since both pursue similar mechanical alignment\u0026mdash;CAS has introduced a conceptual shift: the quantification and measurement of the surgical act. Quantitative control of bone resections and joint balancing has progressively replaced reliance solely on tactile perception, paving the way for the development of robot-assisted surgery. The latter, combining mechanical precision with prosthetic personalization, may in the future demonstrate more tangible clinical advantages.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eAt 15 years of follow-up, computer-navigated TKA did not show significant advantages over the conventional technique in terms of implant survival or functional outcomes. Larger, prospective, and multicenter studies are warranted to confirm these results and to further clarify the evolving role of navigation within the context of robotic and personalized knee arthroplasty.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eEthics statement \u003c/strong\u003eThe study involving human participants was approved by the Institutional Review Board of the Istituto Chirurgico Ortopedico Traumatologico (ICOT), Latina, Italy (protocol number 14/2008). All participants provided written informed consent.\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAccording to our institutional regulations, ethical approval was not required for this retrospective study, as it involved the analysis of fully anonymized data collected during routine clinical practice and did not include any intervention beyond standard care. This study was conducted in accordance with the 1964 Helsinki Declaration and its later amendments.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed Consent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all patients who were successfully contacted for the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors received no funding for this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy conception and design: Pachiarotti, Longo\u0026nbsp;\u003cbr\u003e\u0026nbsp;Data collection and analysis: Longo, Pizzigallo\u003cbr\u003e\u0026nbsp;Manuscript drafting: Longo\u003cbr\u003e Manuscript revision: Todesca, Gumina\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003e\u003cem\u003eRand JA, Coventry MB. Ten-year evaluation of geometric total knee arthroplasty. Clin Orthop Relat Res. 1988;(232):168\u0026ndash;173.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eRitter MA, Faris PM, Keating EM, Meding JB. Postoperative alignment of total knee replacement. Clin Orthop Relat Res. 1994;(299):153\u0026ndash;156.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eBonner TJ, Eardley WGP, Patterson P, Gregg PJ. Effect of postoperative mechanical axis alignment on survival of primary total knee replacement. J Bone Joint Surg Br. 2011;93:1217\u0026ndash;1222.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eParratte S, Pagnano MW, Trousdale RT, Berry DJ. Effect of mechanical axis alignment on 15-year survival. J Bone Joint Surg Am. 2010;92(12):2143\u0026ndash;2149.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eMartin A, Wohlgenannt O, Prenn M, et al.\u0026nbsp;\u003c/em\u003e\u003cem\u003eImageless navigation for TKA increases implantation accuracy. Clin Orthop Relat Res. 2007;460:178\u0026ndash;184.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eL\u0026uuml;tzner J, Dexel J, Kirschner S. No difference between computer-assisted and conventional TKA. Knee Surg Sports Traumatol Arthrosc. 2013;21:2241\u0026ndash;2247.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eHarvie P, Sloan K, Beaver RJ. Computer navigation versus conventional TKA: five-year results. J Arthroplasty. 2012;27:667\u0026ndash;672.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eAbdel MP, Oussedik S, Parratte S, Lustig S, Haddad FS. Coronal alignment in total knee replacement: historical review, contemporary analysis, and future direction. Bone Joint J. 2018;100-B(1 Suppl A):57\u0026ndash;65.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eVan Essen J, Reijman M, Bierma-Zeinstra SMA, van der Linden-van der Zwaag HMJ, Kort NP, Kerkhoffs GMMJ, et al. Kinematic versus mechanical alignment in total knee arthroplasty: a systematic review and meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2023;31(4):1262\u0026ndash;1275.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eMigliorini F, Maffulli N, Cuozzo F, Pilone M, Eschweiler J, Tingart M, et al.\u0026nbsp;\u003c/em\u003e\u003cem\u003eMechanical versus kinematic alignment in total knee arthroplasty: a meta-analysis of clinical outcomes, range of motion, and revision rates. J Arthroplasty. 2025;40(2):342\u0026ndash;351.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eHoppe S, Mainzer JD, Frauchiger L, et al. More accurate component alignment in navigated TKA has no clinical benefit at 5 years. Acta Orthop. 2012;83:629\u0026ndash;633.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eCip J, Obwegeser F, Benesch T, et al. Twelve-year follow-up of navigated versus conventional total knee arthroplasty. J Arthroplasty. 2018;33:1404\u0026ndash;1411.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eKim YH, Park JW, Kim JS. Computer-navigated versus conventional TKA: prospective randomized trial. J Bone Joint Surg Am. 2012;94:2017\u0026ndash;2024.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eBaumbach JA, Willburger R, Haaker R, et al. Ten-year survival of navigated versus conventional total knee arthroplasties. Orthopedics. 2016;39 Suppl 3:S72\u0026ndash;S76.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eOuanezar H, Franck F, Jacquel A, et al.\u0026nbsp;\u003c/em\u003e\u003cem\u003eInfluence of computer-assisted surgery on survivorship of cementless TKA. Knee Surg Sports Traumatol Arthrosc. 2016;24:3448\u0026ndash;3456.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003ede Steiger RN, Liu YL, Graves SE.\u0026nbsp;\u003c/em\u003e\u003cem\u003eComputer navigation for total knee arthroplasty reduces revision rate in patients less than sixty-five years of age. J Bone Joint Surg Am. 2015;97:635\u0026ndash;642.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eBrin YS, Nikolaou VS, Joseph L, et al. Imageless computer-assisted versus conventional total knee replacement: Bayesian meta-analysis. Int Orthop. 2011;35:331\u0026ndash;339.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eHetaimish BM, Khan MM, Simunovic N, et al. Meta-analysis of navigation vs conventional TKA. J Arthroplasty. 2012;27:1177\u0026ndash;1182.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eAllen CL, Hooper GJ, Oram BJ, Wells JE. Does computer-assisted TKA improve overall component position and patient function?\u0026nbsp;\u003c/em\u003e\u003cem\u003eInt Orthop. 2014;38:251\u0026ndash;257.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eAgenas. Sistemi di chirurgia robotica: Report HTA 2025. Roma: Agenas; 2025.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eDesai AS, Moran CG. The use of computer-assisted navigation in total knee arthroplasty: a critical review of cost-effectiveness and clinical outcome. Knee. 2011;18(3):139\u0026ndash;144.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eTrieu J, Lovell M, Donnelly WJ, Crawford R, Dearin J. The cost-effectiveness of computer navigation in primary total knee arthroplasty. EFORT Open Rev. 2021;6(3):238\u0026ndash;247.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eSarpong NO, Geller JA, Cooper HJ, Shah RP, Chen AF. What is the learning curve for new technologies in total joint arthroplasty?\u0026nbsp;\u003c/em\u003e\u003cem\u003eClin Orthop Relat Res. 2020;478(12):2799\u0026ndash;2809.\u003c/em\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"total knee arthroplasty, computer-assisted surgery, navigation, implant survival, long-term follow-up","lastPublishedDoi":"10.21203/rs.3.rs-8196906/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8196906/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eIntroduction:\u003c/strong\u003e The introduction of computer-assisted navigation (CAS) in total knee arthroplasty (TKA) aimed to improve prosthetic alignment and potentially enhance long-term implant survival. However, the actual clinical benefit beyond 10 years remains debated.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods:\u003c/strong\u003e Prospective comparative non-randomized study with a mean follow-up of 15.4 years, including patients undergoing TKA using either a conventional (CONV) or computer-navigated (NAV) technique. The primary outcome was implant survival (absence of revision for any cause). Secondary outcomes were functional scores: Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Fifteen-year implant survival was 70.5% (CONV) vs 73.4% (NAV) (p \u0026gt; 0.05). No statistically significant differences were found in functional outcomes. Mortality unrelated to the prosthesis was high in both groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e At 15 years, the navigated technique did not demonstrate significant advantages over the conventional approach in terms of implant survival or functional outcomes. Larger prospective studies are required to confirm these findings.\u003c/p\u003e","manuscriptTitle":"Computer-Navigated versus Conventional Total Knee Arthroplasty: No Difference in Implant Survival at 15-Year Follow-Up","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-04 08:42:25","doi":"10.21203/rs.3.rs-8196906/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1977c28a-d0a5-47a4-bcc0-17ed6f13ce16","owner":[],"postedDate":"December 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-23T10:54:28+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-04 08:42:25","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8196906","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8196906","identity":"rs-8196906","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}