Finite element analysis of bone‐prosthesis interface micromotion for cementless talar component fixation through critical loading conditions

Abstract

The total ankle replacement (TAR) survivability rate is still suboptimal, and this leads to many orthopaedic surgeons opting arthrodesis as a better option for the ankle arthritis patients. One of the fundamental reasons is due to the lack of primary stability of the prosthesis fixation at the bone‐prosthesis interface hence leading to long‐term aseptic loosening of the talar component. The commercially available Scandinavian Total Ankle Replacement (STAR) Ankle design and several additional design features (including trabecular metal, side fin, double fin, and polka‐dot designs) were studied using finite element analysis, and the bone‐prosthesis interface relative micromotion (BPIRM) and talar bone minimum principal stresses were examined and analysed. Three loading conditions at a gait cycle of heel strike, midstance, and toe off with different meniscal bearing displacement were also included as part of the study parameters. The results were correlated to in vitro cadaveric measurements and reported clinical studies. Simulated results showed that the de‐bonding relative distance between the bone and prosthesis upon loading (COPEN defined by the simulation software) was the main reason constituting to the high interface micromotion between the talar component and talus bone (which could lead to long‐term aseptic loosening). The polka‐dot design was shown to induce the lowest BPIRM among all the designs studied.

Articular geometry can affect joint kinematics, contact mechanics, and implant‐bone micromotion in total ankle arthroplasty

“…The ankle anatomical measurements data obtained from 71 Chinese participants including 56 males and 15 females were used in this study. 11 The mean age was 25.17 years (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37). The mean height, weight, and body mass index were 173.72 ± 6.22 cm, 68.48 ± 11.16 kg, and 22.62 ± 2.94.…”

“…The patient-specific MSK MBD model with TAA has been validated in our previous study by comparing the range of motion (ROM) values predicted by the MSK MBD model with the reported experimental data and numerical results, which has high prediction accuracy. 19 The FE model was validated by comparing the maximum of the insert contact stress and the ROM of the maximum of the implant-bone micromotions of Implant A (INBONE II) predicted by the present study with the reported experimental data and numerical results, [27][28][29] and the results of the detailed comparisons are presented in Table 4.…”

“…Comparisons of the predicted maximum insert contact stress and the range of motion of the maximum of the implant-bone of the micromotions with the reported data [27][28][29]. …”

Total ankle replacement along with subtalar joint arthrodesis: In‐vitro and in‐silico biomechanical investigations

“…Limited experimental evidence is available in ankle biomechanics literature, the interfaces of the bone‐ prosthesis complex are not experimentally available 23 . The biomechanical literature of ankle joint replacement is mostly confined to computational modeling 23–28 . For instance, Reggiani and co‐workers simulated a totally replaced ankle using the FE method, and showed that contact pressures in bone‐prosthesis interfaces exceed 10 MPa at mid‐stance phase of the gait 26 .…”

“…23 The biomechanical literature of ankle joint replacement is mostly confined to computational modeling. [23][24][25][26][27][28] For instance, Reggiani and co-workers simulated a totally replaced ankle using the FE method, and showed that contact pressures in bone-prosthesis interfaces exceed 10 MPa at mid-stance phase of the gait. 26 Ozen et al developed a 3D finite element model of the normal and prosthetic ankle, and reported an increase in stress of talus compared with the normal one.…”