The survivorship of the link endo-rotational hinge total knee arthroplasty: 5–12-year follow-up of 100 patients

Introduction The rate of revision TKA and thus the use of hinged implants (HI) steadily rises. Aseptic loosening lies on the top of the failure patterns. However, no evidence exists until now based on national scale high-caseloads that analyzes the impact of cemented HI stem-design on aseptic survival rates. Methods Data on aseptic HI-revisions with full-cemented tibia-stems were conducted from the German Arthroplasty Registry. Cases were divided in primary HI (PHI) and HI used in revision operations (RHI). Endpoint was a new revision following either a PHI or an RHI. The impact of stem conicity (conical vs. cylindrical), diameter (≤ 13 mm vs. > 13 mm), length (≤ 90 mm vs. > 90 mm) and offset on the 6-Year-Cumulative-Aseptic-Revision-Rate (6Y-CARR) was estimated via Kaplan–Meier curve and compared between groups via Log-Rank-Tests. Results 3953 PHI and 2032 RHI fulfilled inclusion-criteria. Stem conicity had no impact on 6Y-CARR (p = 0.08 and p = 0.8). Diameter > 13 mm hat an impact on PHI (p = 0.05) with lower 6Y-CARR but not on RHI (p = 0.2). Length > 90 mm showed significantly worst 6Y-CARR in PHI (p = 0.0001) but not in RHI (p = 0.3). Offset-stems showed significantly better 6Y-CARR in PHI (p = 0.04), but not in RHI (p = 0.7). Conclusion There was no significant impact of the cemented tibia-stem conicity on 6Y-CARR, neither in PHI nor in RHI. The effect of length, diameter and offset on the 6Y-CARR observed in the PHI, was not detectable in the more complex RHI-cases reflecting its limited clinical relevance by itself in more multifactorial backgrounds. Therefore, results must be interpreted with caution due to considerable system-effects and different utilization-scenarios.

Section: Discussionmentioning

confidence: 99%

Aseptic midterm survival rates between different cemented tibial stem designs in hinged total knee arthroplasty: a 6-year evaluation from the German Arthroplasty Registry

Maslaris,

Grimberg,

Melsheimer

et al. 2024

“…It reduces the stresses on the bone-cement interface [30][31][32] and on the stem-condyle junction, which may otherwise lead to trunnion failure especially when no additional metaphyseal support coexists. Thus, based on the concept of the three fixation zones in RTKA [33], the use of cones [34,35] or sleeves [36][37][38] in combination with a stem extension is becoming even more popular, as it shows improved clinical outcomes and lower rates of aseptic loosening [39][40][41]. Furthermore, offset stems can be useful in preventing component impingement and malalignment, as seen with straight diaphyseal-engaging cementless stems on bones with deformities [42].…”

Section: The Role Of Stem In Rtka Implant Fixationmentioning

confidence: 99%

“…This can be attributed to a cohort inhomogeneity (TKA vs. RTKA, risk factors and complexity of cases, number or previous revisions, septic vs. aseptic, use of metaphyseal fixation, FU time, implant design and fixation technique, missing values, study design, industry influence, etc.) that leads to a wide discrepancy of outcomes that range from excellent [36,40,55,[68][69][70][71][72][73][74][75][76][77] to moderate results [16,20,24,41,62,[78][79][80]. However, when considering recent (2008-2020) high-volume studies that are not associated with a certain implant, the incidence rates of aseptic loosening and PJI are more representative and coincide with our data: Suarez et al in a series of 566 RTKA cases (including 123 PJI) published a 12-year survival of 82% with 19% aseptic loosening and 46% PJI [19].…”

Section: The Role Of Stem Design In Rtka Outcomes: a Comparative Revi...mentioning

confidence: 99%

Does stem profile have an impact on the failure patterns in revision total knee arthroplasty?

Maslaris

Tsiridis

Schoeneberg

et al. 2022

Introduction Revision total knee arthroplasty (RTKA) has been increasing continuously. The results of RTKA still remain unsatisfactory. Failure patterns and risk factors in RTKA were thoroughly analyzed, with periprosthetic joint infections (PJI) and aseptic loosening remaining at the forefront of re-revision (ReRTKA) causes. While there is evidence that stem profile impacts the revisability of cemented implants, its association with the modes of RTKA failure is unknown. Methods 50 consecutive ReRTKA performed in a single orthopedic center during 2016–2017 were retrospectively analyzed. The cases were stratified according to age, sex, number of preexisting revisions, fixation technique, stem design and causes of re-revision. All explanted implants with conical vs. cylindrical stem profiles were compared. Results Mean age was 67 ± 11.5, and 54% were females. 72% of the cases had ≥ 3 previous revisions. 88% were full-cemented, 3% hybrid and 9% press-fit stems. 36% of the RTKA had conical, 58% cylindrical and 6% combined stem profiles. 92% of the RTKA components were removed. Removal causes were: PJI (52.2%), aseptic loosening (34.8%), implant malposition (9.8%), painful knee (1.1%) and instability (2.2%). While the overall RTKA failure patterns were equally distributed between conical and cylindrical stems, subgroup analysis of only cemented ReRTKA revealed a higher incidence of aseptic loosening within cylindrical stem profiles (46.7% vs. 25.7%, P = 0.05). Conclusion Stem profile may have an impact on the process of aseptic loosening in cemented non-metaphyseal engaging RTKA, with cylindrical designs tending to worse outcomes than conical designs. Large cohort studies could provide more clarity on current observation.

“…The difficulty in removing well-fixed stem extensions depends not only on the fixation technique (cemented vs. cementless) or bone quality but also on the design of the stem (diameter, length, offset, surface roughness, crosssection and the conicity of the longitudinal profile). While cementless and hybrid fixation techniques are commonly combined with cylindrical stems [18][19][20][21], cemented fixation has been used for both, conical [22,23] and cylindrical stems [24][25][26][27]. Biomechanical studies have shown that cemented conical stems can be removed easier than cylindrical designs.…”

Section: Introductionmentioning

confidence: 99%

Impact of stem profile on the revisability and the need for osteotomy in well-fixed cemented revision total knee arthroplasty implants

Maslaris

Spyrou

Schoeneberg

et al. 2022

Introduction While re-revision total knee arthroplasty (ReRTKA) steadily increases, the ease and bone-sparing removal of RTKA implants is gaining more and more in importance. Biomechanical data suggest that cemented conical stems can be removed significantly easier than cylindrical stems. However, no clinical evidence exists supporting this observation. Aim of this study was to compare the revisability and need for osteotomy (OT) between removals of well-fixed cemented conical vs. cylindrical RTKA stems. Materials and methods 55 removals of well-fixed full-cemented RTKA stems (29 knees) performed between 2016 and 2018 were retrospectively analyzed. Main outcome variables were: bone loss, fractures, osteotomy incidence, surgery duration, early postoperative complications (EPC), hemoglobin drop and blood transfusion. SPSS was used for the statistical analysis. Results 44.8% were conical, 48.3% cylindrical, and 6.9% combined stem designs. Causes for re-revision were PJI (75.9%), malposition (17.2%) and persistent pain (6.9%). 10 stem removals (18.2%) required an OT (four femoral, six tibial): eight stems (14.5%) had cylindrical and two (3.6%) conical designs (P = 0.041). Fractures were noted solely in removals without OT (11.1% vs. 0%,). There was a tendency to more bone loss in cylindrical stem revisions (53.8% vs. 32%, P = 0.24). A longer overall surgery time was observed in revisions of cylindrical stems (+ 37 min, P = 0.05). There was higher hemoglobin drop and need for blood transfusion in revisions of cylindrical stems or after OT but without reaching statistical significance. The EPC rates were slightly higher in ReRTKA on cylindrical stems (P = 0.28). Conclusion Well-fixed cemented conical stems may be revision friendlier with less demands on OT and shorter overall surgery time than cemented cylindrical stems.