Knee joint laxity is restored in a bi-cruciate retaining TKA-design

Abstract

Purpose The goal is to evaluate the passive stability of a bicruciate retaining, cruciate retaining and bicruciate substituting TKA design in relation to the native knee stability in terms of the laxity envelope. A bicruciate retaining knee prosthesis was hypothesized to offer a closer to normal knee stability in vitro. Methods Fourteen cadaveric knee specimens have been tested under passive conditions with and without external loads, involving a varus/valgus and an external/internal rotational torque, distraction/compression force and an anteroposterior shear force. Subsequently, the native knee, bicruciate retaining, cruciate retaining and finally a bicruciate substituting total knee arthroplasty were tested. Results Through the range of motion, the width of the varus/valgus and internal/external laxity envelope for the native knee and the bicruciate retaining knee were almost equivalent, whereas the cruciate retaining and the bicruciate substituting knee displayed less laxity and more joint distraction. In all prosthetic knees, an equal anteroposterior laxity was seen for the lateral and medial side whereas in the native knee, a difference in laxity was seen between the stable medial side and the more mobile lateral side. Conclusion Bicruciate retaining knee prostheses can restore normal laxity and thus have the potential to offer more normal knee function. Restoration of natural peri‐articular soft‐tissue tension is clinically important because of its obvious effects on joint stability and range of motion. Furthermore, the results of this study could help to establish the ideal ligament tension and laxity in more conventional implants by approaching the normal values for passive knee evaluation as presented here.

Anatomical bi-cruciate retaining TKA improves gait ability earlier than bi-cruciate stabilized TKA based on triaxial accelerometery data: A prospective cohort study

“… 9 BCR TKA can restore normal laxity and thus has the potential to offer more normal knee function with cadaveric specimens. 22 Kono et al. 16 reported that from 30° to 120° of flexion, the lateral side of BCR TKA knees is located significantly more anteriorly than that of normal and unicompartmental arthroplasty knees.…”

Knee kinematics during staircase descent

“…As in previous kinematic studies in the UGKR, 22 the kinematic calculations are based on the framework of Grood and Suntay, 23 allowing for evaluation in six degrees of freedom: knee flexion angle (FA), varus/valgus rotation (VV), internal/external rotation (IE), mediolateral translation (ML), anteroposterior translation (AP), and compression/distraction (CD). In addition to Grood and Suntay, 23 the three translations are separately calculated for both the medial and lateral compartments of the knee.…”

Intratendinous pressure changes in the Achilles tendon during stretching and eccentric loading: Implications for Achilles tendinopathy

“…Compared with previous publications, an adjustment has been made by adding an ankle-foot holder, which allowed movement of the ankle joint in the sagittal plane using two actuators. 21,22 The major advantage of this setup was the preservation of the anatomical connection between the gastrocnemius muscle and the knee, allowing a more physiological tensile load of this bi-articular muscle on the Achilles tendon during ankle plantar-or dorsiflexion. The specimen's foot was inserted in the ankle-foot holder and fixated with three Steinmann pins.…”