Optimal measurement of clinical rotational test for evaluating anterior cruciate ligament insufficiency
Hoshino Y, Kuroda R, Nagamune K, Araki D, Kubo S, Yamaguchi M, & Kurosaka M. Knee Surgery, Sports Traumatology, Arthroscopy. 2011 Aug 18. [Epub ahead of print] doi: 10.1007/s00167-011-1643-5
Evaluations of anterior cruciate ligament (ACL) tears include a battery of clinical tests, including Lachman’s, anterior drawer, and pivot shift test. The pivot shift test is often cited as being able to assess the integrity of the ACL due to its ability to test both the anterior translation and rotational stability of the knee, as well as its ability to reproduce the common symptoms of “giving way.” However, it is difficult to objectively measure the results of this test. The purpose of this study was to compare knee kinematics of 3 clinical evaluation tests (i.e., pivot shift test and internal/external rotation stress test) among ACL deficient knees and ACL intact contralateral knees. 13 patients with unilateral ACL tears, who were undergoing ACL reconstruction surgery, had their knees examined bilaterally under anesthesia immediately prior to surgery. Electromagnetic sensors were placed on the participant’s leg to objectively measure knee kinematic variables while the surgeon performed the manual clinical tests. Significant differences between ACL deficient and intact knees were found in coupled anterior tibial translation (interaction of rotation with translation) as well as acceleration of tibial posterior translation during the pivot shift test. No significant differences were found between ACL deficient and intact knees when evaluating kinematic measurements during internal/external rotation stress tests (e.g., maximal rotation angles, tibial anteroposterior translation).
As clinicians, this study demonstrates the value of the pivot shift test and questions the benefits of pure rotational stress tests performed with knee flexion. The pure rotation stress tests were unable to detect any differences, even when under anesthesia. This study questions the ability of these tests to detect differences between knees with and without an ACL as well as whether they should be used clinically. It would be interesting to see this study replicated with the patients not under anesthesia, in effort to reproduce the traditional clinical setting. This may be important because the pivot shift test sometimes seems unreliable due to the difficult task of getting a patient to relax enough to get a true positive. However, when the pivot shift is performed correctly, it is a valid test for detecting rotary instability in ACL deficient knees. What are your experiences performing these tests?
Written by: Nicole Cattano
Reviewed by: Jeffrey Driban
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Hoshino Y, Kuroda R, Nagamune K, Araki D, Kubo S, Yamaguchi M, & Kurosaka M (2011). Optimal measurement of clinical rotational test for evaluating anterior cruciate ligament insufficiency. Knee Surgery, Sports Traumatology, Arthroscopy PMID: 21850429