Rotational laxity after anterior cruciate ligament injury by kinematic evaluation of clinical tests

Abstract

Despite the numerous studies on anterior cruciate ligament biomechanics and clinical tests, some disagreements still exist in the literature on the role of ACL in restraining rotations and which kinematic test after ACL injuries is the most suitable to evaluate this instability. This work analyses the capability of passive clinical and stress tests to detect an ACL state quantifying rotational instability. The study was conducted on animal knees with a new protocol. We found that an internal-external stress test can give a useful indication on the ACL state when used to estimate the side to side differences while varus-valgus laxity and secondary motions in standard kinematic tests did not seem to be affected by ACL injury. The kinematic protocol performed could be used intra-operatively to quantify rotations, allowing a more accurate evaluation of knee instability to guide surgical reconstruction and improve its final outcome.

Large Animal Models for Anterior Cruciate Ligament Research

“…In the previously mentioned cadaveric study by Kato et al, ATT increased from ~4 to ~15 mm after complete ACL transection (65). These results corroborate observations in an earlier study by Zaffagnini et al, which demonstrated an increase in ATT from 4 mm in pigs with intact knees up to 16 mm following ACL transection (102). ACL transection also resulted in 4–20° of increased laxity in internal-external rotation in the pig knee (102).…”

“…These results corroborate observations in an earlier study by Zaffagnini et al, which demonstrated an increase in ATT from 4 mm in pigs with intact knees up to 16 mm following ACL transection (102). ACL transection also resulted in 4–20° of increased laxity in internal-external rotation in the pig knee (102). Zaffagnini et al suggested, based on their findings in pigs, that evaluation of internal-external rotational laxity, in combination with anterior-posterior laxity, might be helpful in determining ACL status in the human (102).…”

“…ACL transection also resulted in 4–20° of increased laxity in internal-external rotation in the pig knee (102). Zaffagnini et al suggested, based on their findings in pigs, that evaluation of internal-external rotational laxity, in combination with anterior-posterior laxity, might be helpful in determining ACL status in the human (102). Reports of dynamic, in-vivo kinematic evaluation of the porcine knee could not be found, which is surprising given the popularity of this species as a model in ACL research.…”

Use of a Computed Tomography Based Approach to Validate Noninvasive Devices to Measure Rotational Knee Laxity

“…But devices as the KT-1000 arthrometer [ 6 ] are limited to the anterior-posterior translation of the tibia, and studies call into question the intratester and intertester reliability of the device considered as a moderately reliable tool [ 7 , 8 ]. Although reconstructive surgery permits sufficient repair of this ligament [ 9 ] in the sagittal plane, it remains limited in the restoration of rotational stability and no reliable easy-to-use device to measure knee rotation is available [ 10 , 11 ].…”

Anatomic double-bundle versus single-bundle ACL reconstruction: a comparative biomechanical study in rabbits

“…Many animal models have been proposed in the past [1, 15, 30, 41, 47, 77, 88, 98, 104, 105, 114, 116, 126, 127, 130] for the study of the injured knee. Especially the anatomy of the rabbit knee has been well defined and has been found to be comparable with that of the human [27, 35, 66, 97].…”