MRI findings in mucoid degeneration of the cruciate ligaments. Our

MRI findings in mucoid degeneration of the
cruciate ligaments. Our experience.
Scientific Paper N° SP39
E-mail address of corresponding author
[email protected]
Authors
Napoli Augusto1, Carrasco Martin Antonio2, Maida Gustavo2, Martín Eduardo2, Moline
Tomas2, Bruno Claudio Hernan1,2.
1Diagnóstico por Imágenes Adrogué, Buenos Aires, Argentina.
2Fundación Científica del Sur, Buenos Aires, Argentina.
www.fcsur.com
None of the authors have anything to disclose
www.fcsur.com
Introduction
The pathogenesis of mucoid degeneration of the cruciate ligaments (CL) remains unknown,
being the anterior cruciate ligament(ACL) more frequently affected. One theory holds that this
lesion may represent a continuous ligament senile degeneration (age related degeneration). The
second theory considers congenital or acquired synovial tissue entrapment between CL fibres.1
Patients may be symptomatic or asymptomatic. Pain is the most common complaint at
presentation, frequently posterior and in the popliteal cavity. Patients may also be unable to fully
flex or extend the knee. The source of pain is not clear and may be a mechanical or chemical
irritation.1,2
Criteria for CL mucoid degeneration includes ligament bundles poorly differentiated on T1-weighted
images but with discrete fibers easily distinguished on T2 or PD-weighted. Both anterior cruciate
ligament ganglion cysts and mucoid degeneration have a high association with intraosseous cysts
at the femoral and tibial attachments. These findings lend credence to the theory that ACL ganglia
may be part of a degenerative process and that these two entities may represent different
manifestations of this continuum.1,3,5
The lesion may manifest as well as an elongated cyst along the long axis of the CL.
Degenerative changes in PCL and ACL, often coexist.6
Finally this appearances can mimic acute or chronic interstitial partial tears of the ligaments, but its
not associated with knee instability (secondary radiologic signs of CL injury usually are absent).2,3
PURPOSE:
The purpose of our study is to describe our experience on the MRI
features of mucoid degeneration of the cruciate ligaments and their
coexisting lesions.
METHODS:
A descriptive, observational, transversal and retrospective study was
performed in 15 patients who presented signs of mucoid degeneration
of the cruciate ligaments (“celery stalk sign”). We analyzed their
coexisting lesions. The studies were performed in 1.5T and 0.23T
resonators, between June 2009 and May 2013.
RESULTS:
Of 15 examinations, 86.7% had mucoid degeneration of the anterior
cruciate ligament (ACL) and 13.3% implicated the posterior cruciate
ligament (PCL). ACL ganglion cysts were observed in 33.3% of all
patients. Intraosseous cysts were noted in 80% and most commonly at
the ACL tibial insertion. Finally 80% of all patients showed signs of
synovitis.
*
Figure 1. Sagittal PD weighted
image shows an intraosseous cyst at
the distal insertion of the ACL (arrow)
and a ganlion cyst adjacent to its
proximal portion (arrowhead). Note
the intermediate signal intensity of
the ligament (asterisk).
*
Figure 2. Sagittal fat sat T2
weighted image in the same
patient, shows signs of synovitis
(arrowheads) with a heterogeneous
signal intensity of ACL (asterisk).
*
Figure 3. Coronal T2 weighted fat suppressed FSE
image, shows intraosseous cysts (arrows) on tibial and
femoral ACL insertion, and increased signal intensity
within the ligament (asterisk).4
Figure 4. Oblique PD weighted image with
selective angulation to the ACL shows the
“celery stalk sign”, consistent of thickening
and increased intrinsic signal intensity of the
ligament (arrows).4
Figure 5. Sagittal fat sat T2 weighted
image in another patient demonstrates
as well, thickening and hyperintensity of
ACL (arrows). “Celery stalk sign”
representation.
A
CB
*
C
D
Figure 6. Coronal (A) and axial (B) T2 weighted fat suppressed FSE images, shows a
ganglion cyst of ACL (arrow). Note a femoral intraosseous cyst associated (arrowhead).
Sagittal PD weighted images (C, D), with ganlion cyst adjacent to its proximal insertion
(arrow) with fluid signal in the substance of the ligament (asterisk).
*
Figure 7. Sagittal PD weighted image
shows a diffusely altered signal intensity of
the PCL (asterisk).
Figure 8. Sagittal T2 weighted image in
the same patient, with a ganglion cyst
adjacent to the PCL fibers (arrow), and intra
articular fluid with synovitis (arrowhead).
*
A
*
B
C
Figure 9. Mucoid degeneration of PCL. A: Oblique PD weighted image with selective
angulation to ACL shows thickening and high intrinsic signal intensity in the PCL (arrow). B:
Coronal T2 weighted fat suppressed FSE image, with intraosseous cysts (arrow) on their
tibial insertion, and PCL increased signal (asterisk). C: Sagittal PD weighted image. Note
the compromise of PCL (asterisk).
CONCLUSION
In our experience, we observed that mucoid degeneration commonly affect
the ACL. Most of patients had synovitis with erosive bone changes adjacent
to its insertions (intraosseous cysts), and soft-tissue ganglion cysts.
References
1. Papadopoulou P (2007) Signs in Imaging: The Celery Stalk Sign. Radiology 245:3 916-917;
doi:10.1148/radiol.2453050159.
2. Hensen J.J., Coerkamp E.G., Bloem J.L. (2007) Mucoid Degeneration Of The Anterior Cruciate Ligament. JBR–BTR
90: 192-193.
3. Bergin D, Morrison WB, Carrino JA, Nallamshetty SN, Bartolozzi AR (2004) Anterior cruciate ligament ganglia and
mucoid degeneration: coexistence and clinical correlation. AJR 182: 1283–1287.
4. Napoli A, Wulf MI, Bruno CH. EURORAD Case Report (2013, Feb 22). Anterior cruciate ligament mucoid
degeneration: MR findings, {Online}. http://www.eurorad.org/case.php?id=10672.
5. Bergin D., Morrison W.B., Carrino J.A., Nallamshetty S.N., Bartolozzi A.R. Anterior cruciate ligament ganglia and
mucoid degeneration: coexistence and clinical correlation. AJR, 2004, 182: 1283-1287.
6. S L Viana; J L Fernandes; J L Mendonça; F M Freitas. Diffuse intrasubstance signal abnormalities of the posterior
cruciate ligament: the counterpart of the mucoid degeneration of the anterior cruciate ligament? A case series. JBRBTR. 2008 Nov-Dec;91(6):245-8 .