28 research outputs found
Assessment of rotatory laxity in anterior cruciate ligament-deficient knees using magnetic resonance imaging with Porto-knee testing device
Purpose Objective evaluation of both antero-posterior
translation and rotatory laxity of the knee remains a target
to be accomplished. This is true for both preoperative
planning and postoperative assessment of different ACL
reconstruction emerging techniques. The ideal measurement tool should be simple, accurate and reproducible,
while enabling to assess both ‘‘anatomy’’ and ‘‘function’’
during the same examination. The purpose of this study is
to evaluate the clinical effectiveness of a new in-housedeveloped testing device, the so-called Porto-knee testing
device (PKTD). The PKTD is aimed to be used on the
evaluation of both antero-posterior and rotatory laxity of
the knee during MRI exams.
Methods Between 2008 and 2010, 33 patients with ACLdeficient knees were enrolled for the purpose of this study.
All patients were evaluated in the office and under
anesthesia with Lachman test, lateral pivot-shift test and
anterior drawer test. All cases were studied preoperatively
with KT-1000 and MRI with PKTD, and examinations
performed by independent observers blinded for clinical
evaluation. During MRI, we have used a PKTD that applies
antero-posterior translation and permits free tibial rotation
through a standardized pressure (46.7 kPa) in the proximal
posterior region of the leg. Measurements were taken for
both knees and comparing side-to-side. Five patients with
partial ruptures were excluded from the group of 33.
Results For the 28 remaining patients, 3 women and 25
men, with mean age of 33.4 ± 9.4 years, 13 left and 15 right
knees were tested. No significant correlation was noticed for
Lachman test and PKTD results (n.s.). Pivot-shift had a
strong positive correlation with the difference in anterior
translation registered in lateral and medial tibia plateaus of
injured knees (cor. coefficient = 0.80; p\0.05), and with
the difference in this parameter as compared to side-to-side
(cor. coefficient = 0.83; p\0.05).
Considering the KT-1000 difference between injured and
healthy knees, a very strong positive correlation was found
for side-to-side difference in medial (cor. coeffi-
cient = 0.73; p\0.05) and lateral (cor. coefficient = 0.5;
p\0.05) tibial plateau displacement using PKTD.
Conclusion The PKTD proved to be a reliable tool in
assessment of antero-posterior translation (comparing with
KT-1000) and rotatory laxity (compared with lateral pivotshift under anesthesia) of the ACL-deficient knee during
MRI examinatio