The Pivot Shift: Current Experimental Methodology and Clinical Utility for Anterior Cruciate Ligament Rupture and Associated Injury

Abstract

Purpose of review: The purpose of this manuscript is to (1) examine the history, techniques, and methodology behind quantitative pivot shift investigations to date and (2) review the current status of pivot shift research for its clinical utility for management of anterior cruciate ligament (ACL) rupture with associated injuries including the anterolateral complex (ALC).

Recent findings: The pivot shift is a useful physical exam maneuver for diagnosis of rotatory instability related to ACL tear. Recent evidence suggests that the pivot shift is multifactorial and can be seen in the presence of ACL tear with concomitant injury to secondary stabilizers or with predisposing anatomical factors. The presence of a pivot shift post-operatively is associated with poorer outcomes after ACL reconstruction. Recent clinical and biomechanical investigations can help guide clinicians in utilizing pivot shift in diagnosis and surgical planning. Further research is needed to clarify optimal management of ALC in addition to ACL injury.

Keywords: Anterior cruciate ligament reconstruction; Anterior cruciate ligament tear; Anterolateral complex; Physical exam; Pivot shift; Rotatory knee laxity.

Conflict of interest statement

Conflict of Interest

Nicholas J. Vaudreuil, Benjamin B. Rothrauff, and Darren de Sa declare no conflict of interest.

Volker Musahl has done consulting work for Smith & Nephew.

Human and Animal Rights and Informed Consent

All reported studies/experiments with human or animal subjects performed by the authors have been previously published and complied with all applicable ethical standards (including the Helsinki declaration and its amendments, institutional/national research committee standards, and international/national/institutional guidelines).

Figures

Fig. 1

Cadaveric representation of an anatomic double-bundle ACL reconstruction. The native relationship of the ACL to the PCL and intercondylar notch is reestablished. The circle marks the high AM position. (Reprinted with permission) [2]

Fig. 2

Pivot shift quantification methods. (1) The electromagnetic tracking system attached to the bone (direct measurement), (2) electromagnetic tracking system attached to the skin (non-invasive measurement), (3) triaxial accelerometer (non-invasive measurement), and (4) image analysis system (non-invasive measurement). (Reprinted with permission) [25]

Fig. 3

a The PIVOT iPad application software and KiRA accelerometer in clinical use. b The anterior translation of the lateral knee compartment in the PIVOT software interface. c The measured acceleration curve per unit time is plotted by the KiRA software. (Reprinted with permission) [32]

Fig. 4

The in situ force in the ACL and the anterolateral structures throughout the range of flexion for the intact knee (newtons, mean). (Reprinted with permission) [•]