Intraoperative measurement of knee kinematics in reconstruction of the anterior cruciate ligament

Electromagnetic tracking of the pivot-shift

“…Although the instrumented spatial linkage [28][29][30] or robotic system [31,32] can accurately measure the 6 DOF of the knee joint, they are exclusively applicable in cadaveric studies. In vivo evaluation of the 6-DOF knee movements during the pivot-shift test was first performed by Bull et al using the electromagnetic system [33]. They utilized the electromagnetic tracking system intra-operatively by planting sensors into the femur and the tibia with bone pins.…”

“…Instead, a wide variability of tibial axial rotation between specimens was recognized [36]. Their subsequent study of in vivo knee kinematic measurement during the pivot-shift revealed that the abnormal anteroposterior tibial translation was consistently detected, while a large variability was again demonstrated in tibial axial rotation [33].…”

“…Although some might pay more attention to the axial rotational angle change than the anteroposterior translation of the tibia due to the name of the rotational laxity, abnormality of the axial rotation was hard to be detected during the pivot shift test in the ACL-deficient knee because of its inconsistency [18,31,33,37]. The rotational laxity is sometimes misunderstood as rotational angle change against a simple axial rotational stress, but a simple axial rotational stress test is unable to demonstrate abnormal knee kinematics in the ACLdeficient knees [38].…”

The Biomechanics of the Anterior Cruciate Ligament and Its Reconstruction

“…Galway and MacIntosh's (1980) description of the phenomenon (above) certainly looks to describe a rotation. Bull et al (2002) too described a translation and rotation, but both about a medial axis. Noyes et al (1991) measured the kinematics of an ACL-(and medial collateral ligament-) deficient cadaveric knee subjected to the pivot shift test by 11 orthopaedic surgeons.…”

Rotatory knee laxity and the pivot shift

“…Bull et al [1] described this phenomenon as ''envelope of motion'' and used the pivot shift to illustrate that ACLdeficient knees followed the same general path of motion during subluxation and reduction, but that no two knees moved in the same manner. An interesting and still unresolved question is whether we pre-operatively can define and-more difficult-surgically restore knees that display markedly increased rotation?…”