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INTRODUCTION
Pivot shift test is considered as gold standard
clinical examination for diagnosis of anterior
cruciate ligament (ACL) injury. It evaluates the
combined tibio-femoral internal rotation and
anterior tibial translation that occurs when the
ACL is injured or deficient. In 1972, Galway
and Macintosh
et al.
[1] described the test in its
current form and named it “Pivot shift test”.
They used the pivot shift for clinical
examination in patients complaining of “giving
way” of the knee and described it as the most
prominent form of instability of the knee in
patients recovering from severe soft tissue
injury to the knee. This pathological motion
was graded into 3 grades. Subsequently,
various authors like Slocum and Larson,
Hughston, Losee, Lemaire and Jacob studied
this phenomenon and published several
modified techniques to assess this anterolateral
instability [2]. But, Pivot shift test still remains
the most popular and reliable assessment tool
[3]. It has been routinely utilized for pre and
post-operative assessment of the ACL surgery
and considered as most specific test for the
diagnosis of ACL injury, if performed under
anaesthesia [4].
Post-operative pivot shift grading has been
shown to have direct correlation with patient
satisfaction, return to sport and future risk of
development of osteoarthritis [2]. As there is
significant inter-observer variation in knee
laxity assessment, an attempt to measure laxity
in a quantitative & reproducible manner has
been a topic of immense interest lately. This
interest has led to development of tools,
which can provide repeatable and objective
quantification. Improvement in the objective
assessment of knee laxity provides clinicians
with better insight into the injury profile, and
can help to specifically shape treatment
protocols. In this chapter, we have discussed
various aspects of pivot shift test along with
recent advances in making it a quantitative
assessment tool for development of
individualized treatment algorithms.
PATHOMECHANICS &
ELEMENTS OF PIVOT SHIFT
The pivot shift is a complex, multiplanar
manoeuvre that incorporates two main
components: translation (the anterior subluxation
of the lateral tibial plateau followed by its
reduction) and rotation (the rotation of the tibia
relative to the femur). The examiner applies an
internal rotation and valgus force to the extended
knee and if there is ACL incompetence, the tibia
will usually sublux anterolaterally on the femur.
A flexion and valgus force is then applied to the
knee and while flexing the knee; the illiotibial
PIVOT SHIFT TEST:
HOW DOES IT WORK
A. SONI, V. MUSAHL