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Purpose: the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bonepatellar tendon-bone (BPtB) graft have not been established. the purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (smith & nephew, Andover, MA, UsA) after rectangular tunnel ACL reconstruction with BPtB autograft. Methods: thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPtB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (Ct) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D Ct. the clinical outcome was also assessed and correlated with the imaging outcomes. Results: the bone plug was integrated onto the femoral socket in all cases. the incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. no significant association was observed between the imaging outcomes. the postoperative mean Lysholm score was 97.1 ± 5.0 points. the postoperative side-toside difference, evaluated using a Kt-2000 arthrometer, averaged 0.5 ± 1.3 mm. there were no complications associated with EB use. imaging outcomes did not affect the postoperative Kt side-to-side difference. Conclusions: the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPtB autograft. Level of evidence: Level iV, therapeutic case series.

In this study, we propose a measurement technique for evaluating ferroelectric polarization characteristics in ferroelectric field-effect transistors (FeFETs). Different from standard metal/ferroelectric/metal capacitors, the depletion and inversion phenomena in semiconductor substrates have to be carefully taken into account when evaluating the ferroelectric properties using fast voltage sweep as input. The non-equilibrium deep depletion is found to be the limiting factor for the accurate evaluation of ferroelectric properties in metal/ferroelectric/semiconductor capacitors. By connecting the source, drain, and substrate of the FeFET together during the polarization measurement, the deep depletion can be suppressed and the ferroelectricity of the ferroelectric gate can be accurately evaluated. The present technique is a powerful method for capturing the polarization states in FeFETs, enabling new approaches for device characterization and fundamental study, and overcomes the limitation found in the conventional polarization measurement on 2-terminal metal/ferroelectric/semiconductor capacitors.Ferroelectric field-effect transistors (FeFETs), in which ferroelectric thin films are employed as FET gate insulators, are promising for non-volatile memory devices 1-3 and synaptic devices in computing-in-memory applications. 4-6 A substantially increasing interest in FeFETs can be seen after the discovery of ferroelectric HfO 2 7 thanks to its scalability and CMOS compatibility, 3 with FeFETs having excellent performance being continuously reported. [8][9][10][11] So far, the characterization of FeFETs is mainly limited to the standard evaluation of I d -V g characteristics and threshold voltage shift ∆V T as well as their retention and endurance properties. 3,5,[8][9][10][11][12][13][14][15][16][17] On the other hand, the ferroelectric properties of the ferroelectric gate insulators are usually evaluated in an indirect manner, by preparing separate metal/ferroelectric/metal (MFM) capacitors for characterization. 3,5,8,[14][15][16] It is usually assumed that the ferroelectric properties of the separately-prepared MFM capacitors can well reproduce those of the ferroelectric gate insulators in the FeFETs. However, it is questionable whether MFM capacitors can represent the ferroelectricity of the ferroelectric gate insulators, particularly for metal/ferroelectric/semiconductor (MFS, or sometimes called MFIS if the dielectric insulator layer should be emphasized)-type FeFETs, as it is well recognized that the ferroelectric properties of HfO2 is strongly dependent on the underlying and capping layers. [17][18][19][20] To carry out more accurate characterization, MFS capacitors are frequently employed to reproduce the same substrate condition as the ferroelectric gates in FeFETs. 17,21,22 By characterizing MFS capacitors, it has been reported that semiconductor substrates have a significant effect on the ferroelectric properties. 23,24 On the other hand, there are two concerns with the characterization of separate MFS capaci...