Effects of intraarticular contrast media on synovial membrane and cartilage. An electron microscopic evaluation in rabbit knees.

Abstract

To evaluate the histological and ultrastructural alterations in rabbit knee joint cartilage and synovia induced by intraarticular injections of 2 water soluble contrast agents.
The study was conducted at the Department of Orthopedics and Traumatology, Medical Faculty, Osmangazi University, Eskisehir, Turkey in January 2002. To examine the effect of contrast agents on articular cartilage and synovial membrane, rabbit model was used. Specimens from 62 knee joints were examined by light microscopy and transmission electron microscopy one hour, one day, one week and 2 weeks after intraarticular administration of gadolinium-diethylenetriamine pentaacetic acid, iopromide or saline.
In the knees injected with saline, light microscopic changes of the synovium consisted of edema only. Edema and hyperemia were seen in contrast agent injected knees. Ultrastructurally, numerous and large pinocytotic vesicles in A cells of the synovial membrane were seen in contrast agent injected groups. In the knees injected with saline the cartilage were ultrastructurally normal but contrast agent injected knees showed increased activation of chondrocytes with increase of dense glycogen accumulation, large lipid vacuoles and matrix material. There were very rare pycnotic cells in these samples. The rating scale has been used and the means of the total scores were determined for the groups.
The effects of contrast agents reduced gradually on the cartilage and synovium in general but did not become completely normal in the observation period.

Full text

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Effects of intraarticular contrast media on synovial
membrane and cartilage
An electron microscopic evaluation in rabbit knees
Nusret Kose, MD, Ulukan Inan, MD, Cengiz Baycu, PhD, Hakan Omeroglu, MD, Sinan Seber, MD.
A
joint disorders in spite of the introduction and
spread of modern imaging techniques such
as ultrasound, computed tomography and
magnetic resonance imaging (MRI). It can be
used on children and elderly patients without
reservation.
Prior to clinical use, a contrast agent has to
pass through a group of clinical testing with
step-wise advancement for safety reasons. There
is universal consensus that the contrast agents,
especially new generation of radio-opaque
contrast agents, are comfortable and safer for
the patient.1 In the literature, the studies have
focused on acute toxicity and adverse reactions of
the contrast agents.2 With regard to local effects,
unfortunately more limited data are available.
Although previous studies have demonstrated
histological changes in some tissues resulting from
exposure to contrast material, little attention has
been directed to pathological abnormalities of
the synovial membrane and cartilage following
injection of contrast material into the joint.3-5
The purpose of the current study was to
evaluate the histological and ultrastructural
alterations in rabbit knee joint cartilage and
synovia, induced by intraarticular injections of
2 water soluble contrast agents, gadolinium-
diethylenetriamine pentaacetic acid (gd-DTPA)
and iopromide.
rthrography continues to be a valuable
examination technique in the imaging of
Methods. The study was conducted at the
Department of Orthopedics and Traumatology,
Medical Faculty, Osmangazi
Eskisehir, Turkey in January 2002. This study
has been approved by the institutional ethics
committee and principles of laboratory animal
care were followed. Sixty two healthy mature
University,
713
ABSTRACT
Objectives: To evaluate the histological and ultrastructural
alterations in rabbit knee joint cartilage and synovia induced by
intraarticular injections of 2 water soluble contrast agents.
Methods: The study was conducted at the Department of
Orthopedics and Traumatology, Medical Faculty, Osmangazi
University, Eskisehir, Turkey in January 2002. To examine
the effect of contrast agents on articular cartilage and synovial
membrane, rabbit model was used. Specimens from 62 knee joints
were examined by light microscopy and transmission electron
microscopy one hour, one day, one week and 2 weeks after
intraarticular administration of gadolinium-diethylenetriamine
pentaacetic acid, iopromide or saline.
Results: In the knees injected with saline, light microscopic changes
of the synovium consisted of edema only. Edema and hyperemia
were seen in contrast agent injected knees. Ultrastructurally,
numerous and large pinocytotic vesicles in A cells of the synovial
membrane were seen in contrast agent injected groups. In the knees
injected with saline the cartilage were ultrastructurally normal
but contrast agent injected knees showed increased activation of
chondrocytes with increase of dense glycogen accumulation, large
lipid vacuoles and matrix material. There were very rare pycnotic
cells in these samples. The rating scale has been used and the
means of the total scores were determined for the groups.
Conclusions: The effects of contrast agents reduced gradually
on the cartilage and synovium in general but did not become
completely normal in the observation period.
Saudi Med J 2007; Vol. 28 (5): 713-716
From the Department of Orthopedics and Traumatology (Kose, Inan, Omeroglu,
Seber), Department of Histology (Baycu), Eskisehir Osmangazi University Faculty of
Medicine, Meselik, Eskisehir, and the Department of Orthopedics and Traumatology
(Omeroglu), Faculty of Medicine, Ufuk University, Ankara, Turkey.
Received 8th October 2006. Accepted 31st December 2006.
Address correspondence and reprint request to: Dr. Nusret Kose, Associate Professor of
Orthopedics and Traumatology, Department of Orthopedics and Traumatology, Faculty
of Medicine, Eskisehir Osmangazi University, Meselik, Eskisehir 26480, Turkey. Tel.
+90 (222) 2392979. Fax. +90 (222) 2393774. E-mail: nkose@ogu.edu.tr

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rabbits weighing 2.5-3 kg were used in the study. The
study was carried out under general anesthesia, induced
with intramuscular ketamine hydrochloride (Ketalar)
(50 mg/kg). Animals were randomly divided into 3
groups as dimeglumine, iopromide and control groups.
After surgical preparation of a small area over the knee
joint, an aseptic puncture was performed using 24-
gauge, 19 mm disposable needles. Needle placement
in the joint space was verified by aspiration of synovial
fluid. In 20 rabbits, the right knees were injected with
1 ml of gd-DTPA (Magnevist®). In another 20 rabbits,
the right knees were injected with 1 ml of iopromide
(Ultravist®). The remainder 20 knees served as control
and injected with 1 ml saline.
Gadopentetate dimeglumine
methylglucamine salt of the gadolinium complex
of DTPA, and is an injectable contrast medium for
MRI. Iopromide is a nonionic, iodinated, low-osmolar
radiological contrast agent recommended especially for
intravascular administration.
The groups of animals were observed in cages. The
animals, 5 in each group, were killed with intraperitoneal
high dose sodium thiopental after 1 hour, 1 day, 1 week
and 2 weeks. By the same aseptic technique biopsies
of the synovial membrane and articular cartilage
were obtained for histologic examination via knee
arthrotomy. Specimen were placed in 5% glutaraldehyde
with phosphate buffer solution and fixed for overnight
at +5°C temperature. Tissues were postfixed in 1%
osmium tetroxide solution for 1 hour. Tissues were
dehydrated using graded alcohol and embedded in
Araldite. Semi-thin sections were stained with toluidine
blue and examined under light microscopy (Olumpus
PM10-ADS). Selected areas were routinely prepared
for transmission electron microscopy and examined
using Jeol 1220 EM with 80 kV. The histologist had
no knowledge of the material injected or how long after
injection the animal had been killed. In the 2 rabbits,
which had not received any intraarticular injections, the
cartilage and the synovium of the knees were examined
to determine the normal appearance.
Each histological change in tissues was rated semi-
quantitatively on a scale of 0 to 3. Zero represented a
normal appearance, 1 minimum, 2 moderate and 3
severe changes. Study groups and control group were
compared to evaluate the effects of t§he contrast
media on the synovial membrane and joint cartilage.
Statistical significance between individual test groups
was determined by Mann-Whitney U test, with p-value
less than 0.05 considered significant.
is the N-
Results. All animals survived the entire duration
of the study. On clinical observation rabbits appeared
normal. None of the rabbits had infection on their
knee joints visually. In the knees injected with saline,
or contrast media the cartilage and synovium appeared
normal on gross pathological examination.

Light microscopy. In the knees injected with saline
only minimal hypertrophic chondrocytes were observed
in the cartilage tissue in the first week. In the knees
injected with iopromide and dimeglumine, many
changes were observed in the cartilage tissue such as
hypertrophy of chondrocytes, accumulation of dense
glycogen, and weak glycosaminoglycan staining of
matrix material in the first week (Figure 1). Very rare
pycnotic chondrocytes were also seen. These findings
decreased gradually by the second weeks. No superficial
erosion, pannus or grouping of chondrocytes were
observed on any samples.
Figure 1 - Densely stained glycogen in chondrocytes of dimeglumine
injected group.
Figure 2 - Dense glycogen accumulation and darkly stained chondrocyte
after 1 week dimeglumine injection.

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Effects of contrast agents on a joint ... Kose et al
of the contrast agents has been used frequently in
clinical practice. The most important physicochemical
properties of contrast agents are their solubility,
viscosity, osmolality, hydrophilia, and electrical charge.1
There are 2 components to contrast media toxicity;
high osmolality and chemotoxicity.6 Mild and transient
post-procedural pain and swelling are not uncommon
following arthrography. These symptoms and signs have
been attributed to a possible irritant effect of contrast
media on the synovium, a decrease in the pH of the
joint fluid, or joint distension provoked by additional
influx of fluid into an already distended joint.1,3
In the literature the effect of various contrast agents
have been studied almost exclusively from a clinical
point of view. Direct observations are rare. Although
it is considered safe for systemic use of water-soluble
contrast media, toxicities in some tissues have been
identified. Gabelmann et al7 reported that ionic contrast
agents lead to reversible transient focal endothelial cell
injury following intraaortic injection. Despite their
widespread use in musculoskeletal diagnosis, contrast
agents have received relatively little attention on their
effect on cartilage and synovial membrane after intra-
articular administration.
In one study to determine whether the contrast
medium- after being incorporated into the hyaline
articular cartilage- was stored in the chondrocytes,
uptake experiments were carried out in vitro on rabbit
knee-joint cartilage with radioactive contrast media.
One fourth of the original radioactivity of the medium
was found in the innermost layer after 48 hours.
These experiments showed that gadolinium is taken
up completely into the hyaline cartilage, and that this
Figure 3 - Increased of matrix material in dimeglumine injected group.
Figure 4 - Numerous and large pinocytotic vesicle in A cells of synovial
membrane.

of edema and hyperemia in the first hours in iopromide
and dimeglumine injected groups. Hyperemia persisted
slightly in the first and second weeks. Synovial membrane
was histologically intact. In the knees injected with SF
light microscopic changes of the synovium consisted of
edema only.

Electron microscopy. In the knees injected with SF
the cartilage were ultrastructurally normal. Whereas
in those injected with dimeglumine and iopromide
increased activation of chondrocytes with increase of
glycogen accumulation, large lipid vacuoles and matrix
material were observed (Figure 2-3). These observed
changes were not severe. Ultrastructurally, numerous
and large pinocytotic vesicles in A cells of synovial
membrane were seen in contrast agent injected groups
(Figure 4).
The rating scale for each histological change in
tissues on the light microscopic examination has been
used and the means of the total scores were determined
for the groups. The effects of these contrast agents
reduced gradually on the cartilage and synovium in
general but did not became normal completely. The
mean score of dimeglumine elevated from 0.7-2.7 in
7 days and reduced to 2 in 14 days while the mean
score of iopromide reduced from 2.7-1.7 in 14 days on
cartilage. The paired comparisons between dimeglumine,
iopromide and control revealed no significant difference
between groups at 1 hour, 1 day, 1 week and 2 weeks
after injection (p>0.05).
Light microscopic changes of the synovium consisted
Discussion. To improve the accuracy of visualization
in the diagnosis of joint disorders, intraarticular injection

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Effects of contrast agents on a joint ... Kose et al
Saudi Med J 2007; Vol. 28 (5) www.smj.org.sa
process is time-dependent. The contrast medium is
similarly taken up into the cartilage matrix.8
Few studies have examined the toxicity of contrast
media on articular cartilage and synovium. Rahmouni et
al9 found that cell viability, measured by uptake of neutral
red, was decreased by a supratherapeutic concentration
of a contrast agent. Safety of intraarticular contrast media
was examined in another study, where solution of Gd-
DTPA were injected into rabbit knees. Gross inspection
and light microscopy revealed some focal hyperplasia of
the synovium and focal mononuclear infiltrate of the
synovium in some knees a few hours after injection with
uncertain significance.4 Greisberg et al10 have shown that
exposure to contrast agents can alter chondrocyte matrix
production and cellular proliferation, and can also
induce apoptosis of chondrocytes at the concentrations
used for arthrography in monolayer cell cultures.
In this study, the observed changes when correlated
with those that had been demonstrated by electron
microscopy showed that intraarticular injections of
contrast media produce histological and ultrastructural
alterations in rabbit knee joint cartilage and synovia.
The effects of these contrast agents reduced gradually
on the cartilage and synovium in general but did not
become normal completely. In this study, adverse local
effects of contrast agents have been demonstrated by
high dose exposure in rabbit joint cartilage. This effect
would be of more concern if injection into an immature
joint was performed. We are aware of the limitations
of our experimental model. In fact, the low number of
animals examined in each group restricted the statistical
significance of the results. But it is possible that contrast
media effects may have been underestimated to some
degree. Further work is needed to determine if these
effects are of clinical importance.
References
1. Stacul F. Current iodinated contrast media. Eur Radiol 2001;
11: 690-697.
2. Goldstein HA, Kashanian FK, Blumetti RF, Holyoak WL,
Hugo FP, Blumenfield DM. Safety assessment of gadopentetate
dimeglumine in U.S. clinical trials. Radiology 1990;
174: 17-23.
3. Pastershank SP, Resnick D, Niwayama G, Danzig L, Haghighi
P. The effect of water-soluble contrast media on the synovial
membrane. Radiology 1982; 143: 331-334.
4. Hajek PC, Sartorius DJ, Gylys-Morin V, Haghighi P, Engel A,
Kramer F, et al. The effect of intra-articular gadolinium-DTPA
on synovial membrane and cartilage. Invest Radiol1990; 25:
179-183.
5. Corbetti F, Malatesta V, Camposampiero A, Mazzi A, Punzi L,
Angelini F, et al. Knee arthrography: effects of various contrast
media and epinephrine on synovial fluid. Radiology 1986; 161:
195-198.
6. Dawson P. Structure - Toxicity relationships and molecular
design. In: Contrast Media in Practice. Dawson P, Clauß W,
editors. Berlin: Springer Verlag; 1994. p. 11-12.
7. Gabelmann A, Haberstroh J, Weyrich G. Ionic and non-ionic
contrast agent-mediated endothelial injury. Quantitative
analysis of cell proliferation during endothelial repair. Acta
Radiol 2001; 42: 422-425.
8. Engel A. Magnetic resonance knee arthrography. Enhanced
contrast by gadolinium complex in the rabbit and in humans.
Acta Orthop Scand 1990; 240: 1-57.
9. Rahmouni A, Mathieu D, Chambou C, Dao TH, Hernigou P,
Vasile N. Intraarticular tolerability and kinetics of gadolinium
tetra-azacyclododecane tetraacetic acid. Acad Radiol 1995; 2:
413-417.
10. Greisberg JK, Wolf JM, Wyman J, Zou L, Terek RM.
Gadolinium inhibits thymidine incorporation and induces
apoptosis in chondrocytes. J Orthop Res 2001; 19: 797-801.
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