Total and partial knee arthroplasty implants that maintain native load transfer in the tibia

Abstract

Aims Unicompartmental and total knee arthroplasty (UKA and TKA) are successful treatments for osteoarthritis, but the solid metal implants disrupt the natural distribution of stress and strain which can lead to bone loss over time. This generates problems if the implant needs to be revised. This study investigates whether titanium lattice UKA and TKA implants can maintain natural load transfer in the proximal tibia. Methods In a cadaveric model, UKA and TKA procedures were performed on eight fresh-frozen knee specimens, using conventional (solid) and titanium lattice tibial implants. Stress at the bone-implant interfaces were measured and compared to the native knee. Results Titanium lattice implants were able to restore the mechanical environment of the native tibia for both UKA and TKA designs. Maximum stress at the bone-implant interface ranged from 1.2 MPa to 3.3 MPa compared with 1.3 MPa to 2.7 MPa for the native tibia. The conventional solid UKA and TKA implants reduced the maximum stress in the bone by a factor of 10 and caused > 70% of bone surface area to be underloaded compared to the native tibia. Conclusion Titanium lattice implants maintained the natural mechanical loading in the proximal tibia after UKA and TKA, but conventional solid implants did not. This is an exciting first step towards implants that maintain bone health, but such implants also have to meet fatigue and micromotion criteria to be clinically viable. Cite this article: Bone Joint Res 2022;11(2):91–101.

The risk of tibial eminence avulsion fracture with bi-unicondylar knee arthroplasty

“…Other researchers have made similar assumptions, using cortical strain measurements as a basis for validation of bone FE models investigating fracture. 19,[45][46][47][48] While direct data to validate peri-implant bone strains were not available, the internal stress distribution predicted by the model was found to be similar to recently published experimental measurements, 49 verifying that the predicted peri-implant cancellous bone stresses were representative of reality (Supplementary Figure b). This research did not study fracture propagation, 50 with MPES-95 used as a surrogate measure to determine whether fracture would occur.…”

Restoration of preoperative tibial alignment improves functional results after medial unicompartmental knee arthroplasty

“…Finally, the angular analyses were performed on two types metal‐back implants and using an extramedullary cutting guide. Full polyethylene implants or implants with resurfacing techniques were excluded, and thus, angular analyses cannot be extrapolated to all types of prostheses and the type of implant used can affect stresses at the implant–bone interface and potentially influence clinical results [22].…”

Bioreactor analyses of tissue ingrowth, ongrowth and remodelling around implants: An alternative to live animal testing

“…Secure implant fixation in bone is necessary for a successful outcome for a wide range of surgical procedures, including arthroplasty, spine fusion, fracture fixation, and dental implants, impacting millions of patients worldwide each year ( Pabinger et al, 2015 ; Abbott et al, 2017 ; Pabinger et al, 2018 ; Borgström et al, 2020 ). The field is rife with innovation, including new implant technologies such as additively manufactured porous structures ( Brogini et al, 2021 ; Munford et al, 2022 ) nano coatings ( Bai et al, 2021 ) and biophysical stimulation ( Soares dos Santos et al, 2016 ; de Sousa et al, 2021 ), as well as novel approaches to design ( van Arkel et al, 2018 ; Wang et al, 2021 ) and innovation in surgical technique ( Doyle et al, 2019 ; Doyle et al, 2020 ).…”

“…The aim of this research is to analyse whether ex vivo bone models can be used to assess bone remodelling into, onto and around new implant fixation technology. Porous stochastic titanium scaffolds were used as an example implant technology given the large research interest in these structures for arthroplasty implants ( Ghouse et al, 2019 ; Reznikov et al, 2019 ; Dion et al, 2020 ; Brogini et al, 2021 ; Munford et al, 2022 ), and two culture conditions were explored to understand the effects of research design on ex vivo bone remodelling and implant bony ingrowth.…”

“…While static culture conditions exhibited some characteristics of bony adaptation to implantation, simulating physiological conditions with a bioreactor led to an accelerated response. innovation, including new implant technologies such as additively manufactured porous structures (Brogini et al, 2021;Munford et al, 2022) nano coatings (Bai et al, 2021) and biophysical stimulation (Soares dos Santos et al, 2016;de Sousa et al, 2021), as well as novel approaches to design (van Arkel et al, 2018;Wang et al, 2021) and innovation in surgical technique (Doyle et al, 2019;Doyle et al, 2020).…”