Physician

Tip 1

Tip 2

Tip 3

Double-check the correct choice of adapter, especially when using 2-zone or 3-zone cones. The laser marking is as follows (left/right or XS/S or H30/ H45)

Tip 4

The Femoral Compressors have 2 functions. They serve as a rasp and as a trial implant. In order to check that the fit is correct, it is necessary to carry out a trial reduction with all the trial components from the Endo-Model Knee Family. After trial reduction, it may be advantageous to leave the femoral compressor in situ until shortly before implantation of the final implant.

Tip 5

Tip 6

Tip 7

If it is necessary to reposition or explant the Femoral or Tibial Cone, the respective extraction forceps can be used after releasing the bony connection and removing the bone cement. In the event of a revision, both extraction forceps, i.e. for Femoral Cones or Tibial Cones, can be connected to the M12 thread of the forceps with a slap hammer.
After intramedullary insertion, the forceps grab underneath the cone rim. Repositioning of a Femoral Cone can also be done with the femoral impactor (see Tip 2).

Tip 8

Tip 9

Tip 10

TrabecuLink Cones: Biomechanical Analysis of TrabecuLink Flexible Femoral Cones in Endo-Model Hinged Total Knee Arthroplasty

Prof. Bernardo Innocenti, PhD

Major Findings

• Flexible Cone reduces bone stress during implantation, lowering the risk of bone fracture;
• Flexible Cone better distributes stress over the bone, improving implant stability;
• Flexible Cone does not alter the implant performance obtained with the rigid cones;
• Flexible Cone guarantees the same negligible implant micromotions obtained with the use of rigid cones.

To receive the complete FEA paper in print or PDF version, please contact us at info-flexicones@linkhh.de

Comparative Biomechanical In Vitro Study of Different Modular Total Knee Arthroplasty Revision Stems With Bone Defects

Dario Guttowski, Dr Med a, *, Valerie Polster, Dipl -Ing b, Gerd Huber, Dr Ing b, MichaelM.Morlock,Prof Dr b, Klaus Püschel, Prof Dr Med c, Jakob Nüchtern, PD,DrMed a

Abstract
Background
The aim of this study is to investigate the effects of different stem lengths and types including cones on primary stability in revision total knee arthroplasty with different femoral bone defects and fixation methods in order to maximize bone preservation. It is hypothesized that longer stems provide little additional mechanical stability.

Methods
Thirty-five human femurs were investigated. A distal bone defect, Anderson Orthopedic Research Institute classification (s. 33) type-F2a, was created in group 1-3 and type-F3 in group 4-6. A cemented, rotating hinge femoral component was combined with different stems (100 and 160 mm total or hybrid cemented cones, or a 100-mm custom-made anatomical cone stem). The femora were loaded according to in vivo loading during gait. Relative movements were measured to investigate primary stability. Pull-out testing was used to obtain a parameter for the primary stability of the construct.

Results
Relative movements were small and similar in all groups (<40 μm). For small defect, the pull-out forces of cemented long (4583 N) and short stems (4650 N) were similar and about twice as high as those of uncemented stems (2221 N). For large defects, short cemented stems with cones showed the highest pull-out forces (5500 N). Long uncemented stems (3324 N) and anatomical cone stems (3990 N) showed similar pull-out forces.

Conclusion
All tested stems showed small relative movements. Long cemented stems show no advantages to short cemented stems in small bone defects. The use of cones or an anatomical cone stem with hybrid cementation seems to offer good stability even for larger bone defects. The use of a short cemented stem (with or without cone) may be a suitable choice with a high potential for bone preservation in total knee arthroplasty revision with respective bone defects.

Learn more here

Longer Femoral Cones addresses even zone 2.5.

For more LINK product webinars visit our: Medical Education Webinar Channel

©2015 The British Editorial Society of Bone & Joint Surgery.

Learn more about the zonal fixation here

METAPHYSEAL CONES AND SLEEVES IN REVISION TOTAL KNEE ARTHROPLASTY: TWO SIDES OF THE SAME COIN?

Complications, clinical and radiological results—a systematic review of the literature A. Zanirato¹ · M. Formica¹ · L. Cavagnaro² ·
S. Divano¹ · G. Burastero² · L. Felli¹ Received: 10 December 2018 / Accepted: 8 February 2019 © Istituto Ortopedico Rizzoli
2019

Abstract
Revision total knee arthroplasty (rTKA) is increasing of relevance in orthopaedic surgeon daily practice and this trend is likely to continue in the years ahead. The aim of this systematic review of English literature is to summarize and compare indications, complications, clinical and radiological results of metaphyseal cones and sleeves in management of bone loss in rTKA. Retrospective or prospective studies with at least 1 year of follow-up (FU) were included. The PRISMA 2009 flowchart and checklist were considered to edit the review. Clinical and radiological results, rates of intraoperative fractures, aseptic loosening, periprosthetic joint infection, septic failure, reoperations and re-revisions were extrapolated by the papers. Thirty-seven articles were included in the systematic review. Results of 927 cones (mean FU of 3.6 ± 1.4 years) and 1801 sleeves (mean FU of 4.5 ± 1.6 years) were analysed. The studies showed good clinical and functional outcomes. Cones and sleeves allowed a stable metaphyseal fixation. The aseptic survivorship of the implants was 97.3% in cones group and 97.8% in sleeves group. Metaphyseal cones and sleeves represent a viable option in management f type IIb and III AORI bone defects in aseptic and septic TKAr with overlapping survival rate. Further high-quality long-term studies would better clarify complications, clinical and radiological results of these promising techniques in revision total knee arthroplasty.

Learn more here