Strength of repaired cruciate ligament can be evaluated using
new imaging process
8 March 2015
A new imaging technique using magnetic resonance tomography can
evaluate precisely both the load-bearing capacity of the "new"
cruciate ligament and the risk of a renewed rupture. The new
technique was developed for clinical use at the MedUni Wien.
A footballer is able to play football again or to recommence
training six months after an operation on a cruciate ligament
rupture in case of a normal healing process. This interruption is
common in professional football, but it is merely an empirical
value, as Siegfried Trattnig from the University Clinic for
Radiology and Nuclear Medicine at the MedUni Wien (Medical
University of Vienna) has emphasised.
In the new process, the so-called gagCEST technique is used, the
basic principle of which originates from New York University. The
methodological further development for application in clinics was
then conducted at the Centre of Excellence for High Field MR at the
University Clinic for Radiology and Nuclear Medicine at the MedUni
Wien, and has now been used for the first time on patients with an
operative replacement of the anterior cruciate ligament.
It is possible to measure important components of the cartilage,
menisci and knee joint ligaments; the glycosaminoglycans (GAG). They
represent a general biomarker for the biomechanical properties of
knee joint structures.
In case of a cruciate ligament operation following a rupture of
the anterior cruciate ligament, a tendon from the patient themselves
— usually a tendon from the thigh — is used as a replacement
cruciate ligament to replace the damaged one. "The human body reacts
to this by converting this tendon into a ligament again in a process
lasting several months", the MedUni Wien expert explains on the
occasion of the European radiologist congress, ECR, which takes
place from the 4th to 8th March in the Austria Center Vienna.
The stability of the ligament could not up to now be determined
using the current standard magnetic resonance, but this can be
achieved using the new gagCEST technology.
Trattnig said, "The more glycosaminoglycans we can measure in the
new ligament, the better its stability and load-bearing capacity. As
a result, we can measure precisely when, depending on the measured
values during the healing process, a higher load can be placed on
the knee and also whether the so-called ligamentization, ie the
conversion of the tendon to a ligament, is still in progress and
there is therefore still a risk of a renewed rupture of the cruciate
This new technology has now been used for the first time using a
7-Tesla ultra-high field magnetic resonance tomography at the MedUni
Wien, but it can also be applied during methodological further
development using the 3-Tesla devices normally in operation.