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PolyNaSS bioactivation of LARS artificial ligament promotes human ligament fibroblast colonisation in vitro

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Soucounda Lessim
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Véronique Migonney at Université Paris 13 Nord
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Didier Lutomski at Université Paris 13 Nord
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Abstract and Figures

Background: Introduction of a new generation of artificial ligaments for ACL reconstruction, the Ligament Augmentation and Reconstruction System (LARS), gives promising clinical results [1]. The current literature supports the use of LARS from short to medium term. To go even further to improve the biocompatibility of this biomaterial, poly(sodium styrene sulfonate) (polyNaSS) was grafted onto its surface. Studies using sheep animal model showed improvement of knee functionalities with this grafted artificial ligament and a better adhesion of human cell lines. Objectives: To better understand this in vivo improvement of integration with the bioactivated artificial prosthesis, in vitro studies were leaded using human ligament fibroblasts. Methods: Human ligament fibroblasts isolated from human ruptured ACL were amplified and seeded onto poly(NaSS) grafted and non-grafted PET scaffold (Lars ligament) under standard culture conditions. Cellularized fibers were observed under scanning electron microscopy and histological and immunohistological studies were performed. Results: Cells are localized around the grafted PET fibers of the bioactive ligament and penetrate in the scaffold. On ungrafted fibers, cells stay around the scaffold. On grafted fibers, collagen I appears strongly organized whereas is thin and dispersed on non grafted fibers. Finally, grafting altered localization of decorin. Conclusions: PolyNaSS grafting enhances human ligament fibroblast organisation in vitro in contact with biomaterial and improves collagen and decorin deposits around fibers.
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Bio-Medical Materials and Engineering 00 (20xx) 1–9 1
DOI 10.3233/BME-130753
IOS Press
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PolyNaSS bioactivation of LARS artificial
ligament promotes human ligament fibroblast
colonisation in vitro
Soucounda Lessim, Véronique Migonney, Patricia Thoreux, Didier Lutomski ∗and
Sylvie Changotade
UFR SMBH, Université Paris 13 Sorbonne Paris Cité, Bobigny, France and Laboratoire de
Biomatériaux et Polymères de Spécialité, LBPS/CSPBAT CNRS UMR 7244, Université Paris 13
Sorbonne Paris Cité, Villetaneuse, France
Abstract.
BACKGROUND: Introduction of a new generation of artificial ligaments for ACL reconstruction, the Ligament Augmen-
tation and Reconstruction System (LARS), gives promising clinical results [1]. The current literature supports the use of LARS
from short to medium term. To go even further to improve the biocompatibility of this biomaterial, poly(sodium styrene sul-
fonate) (polyNaSS) was grafted onto its surface. Studies using sheep animal model showed improvement of knee functionalities
with this grafted artificial ligament and a better adhesion of human cell lines.
OBJECTIVES: To better understand this in vivo improvement of integration with the bioactivated artificial prosthesis, in
vitro studies were leaded using human ligament fibroblasts.
METHODS: Human ligament fibroblasts isolated from human ruptured ACL were amplified and seeded onto poly(NaSS)
grafted and non-grafted PET scaffold (Lars ligament) under standard culture conditions. Cellularized fibers were observed
under scanning electron microscopy and histological and immunohistological studies were performed.
RESULTS: Cells are localized around the grafted PET fibers of the bioactive ligament and penetrate in the scaffold. On
ungrafted fibers, cells stay around the scaffold. On grafted fibers, collagen I appears strongly organized whereas is thin and
dispersed on non grafted fibers. Finally, grafting altered localization of decorin.
CONCLUSIONS: PolyNaSS grafting enhances human ligament fibroblast organisation in vitro in contact with biomaterial
and improves collagen and decorin deposits around fibers.
Keywords: Anterior cruciate ligament (ACL), fibroblast, matrix, biointegration, biomaterial, bioactive surface
1. Background
Different methods have been used to restore knee stability after anterior cruciate ligament (ACL) rup-
ture. One of them is the use of patellar tendon or iliotibial tract. However the use of these autogenic
tissues has some drawbacks related to donor site morbidity and the delay to recover normal physi-
cal performance. Reconstruction by allograft carries risk of infection and disease transmission. The
use of artificial ligaments which avoid those complications may offer a good alternative. Among them,
polyethylene terephtalate (PET) ligament represent a good candidate because of its mechanical proper-
ties resistance and elasticity. However, ruptures and synoviotis were frequently observed with this PET
*Address for correspondence: Didier Lutomski, UFR SMBH, Université Paris 13 Sorbonne Paris Cité, 74, rue Marcel Cachin,
93017 Bobigny, France. Tel.: +33 1 48 38 77 54; Fax: +33 1 48 38 77 53.
0959-2989/13/$27.50 ©2013 – IOS Press and the authors. All rights reserved
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prosthesis mainly due to the abrasion of the fiber structure and the uncontrolled inflammatory response
leading to low tissue integration. The “biointegration” of these materials is one of the key of success
for surgery. In order to improve the host response, which depends on the physico-chemical properties of
the polymer surface, we developed with the LARS company a new bioactive PET ligament prosthesis
by grafting a bioactive polymer, poly(sodium styrene sulfonate) (polyNaSS), onto LARS prosthesis sur-
face [2–4]. Previous studies, showed improvement of the knee functionalities with the grafted artificial
ligament in the sheep and a better adhesion of human cell lines [5–7].
2. Objectives
The aim of this study was to investigate the behaviour of human ligament fibroblasts onto a functional-
ized artificial ACL prosthesis, focusing on 3D cell proliferation, morphology, organization and synthesis
of extracellular matrix components. LARS ligament was made bioactive by grafting of PolyNaSS, an
anionic polymer [2–5].
3. Methods
3.1. Cell isolation
Human ACL fibroblasts (hLF) were isolated from human ruptured Anterior Cruciate Ligament (rACL)
from three patients aged from 22 to 56 years old undergoing knees anterior cruciate ligament reconstruc-
tion.
Cells were isolated by enzymatic digestion under sterile conditions according to the method described
by Kobayashi et al. [8] and Nagineni et al. [9]. Briefly tissues were cut into small pieces (1 ×1 mm),
thoroughly washed in phosphate buffered saline (PBS), placed into centrifugation tube and covered with
6 ml of collagenase type IA (1 mg/ml) (Sigma, France) for 6 h at 37◦C, under shaking. Cells suspen-
sions were then centrifuged at 2,100 rpm for 10 min. Cell pellets were then rinsed twice with PBS
and resuspended in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 20% foetal calf
serum (FCS) and antibiotics (penicillin, streptomycin) in a 25 cm2flask and incubated at 37◦Cand
5% CO2. Culture medium was renewed every 3 days. After 72 h, non-adherent cells were removed by
changing medium. When reaching 70–80% confluence, adherent cells were freed from the flask with
0.05% trypsin-EDTA and sub-cultured in a 75 cm2flask (Corning) DMEM containing 10% FCS, peni-
cillin (100 U/ml), streptomycin (100 µg/ml). A homogenous fibroblasts population was obtained after
2 weeks of culture. When reach sufficient number, cells are freed as previously described, centrifuged at
500 g during 10 min and resuspended at sufficient concentration for following experiments.
3.2. LARS ligament preparation
Samples used for this study were knitted PET fabrics of 3 ×1.0cm
2in size and 1.1 mm in thickness
[10–12]. The knitted fabrics were provided by the LARS Company (Arc sur Tille, France) and were
fabricated by the same process used to produce artificial ligaments [4,13]. PET fabrics were washed
sequentially at ambient temperature, in tetrahydrofuran (THF) for 15 min and intensively wash in double
distilled water. Samples were incubated for 10 min in a sodium carbonate solution (5%, m/v), in a
sleazy boiling. Once reached, articular fibers were washed again in double distilled water, and then dried
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under vacuum at 50◦C for 1 h. Knitted PET are conditioned by a series of washing before seeding cells
according to the method described by Migonney et al. [14]. Poly(NaSS) grafted and non-grafted samples
are referenced “grafted or non grafted scaffold”.
3.3. Proliferation onto LARS ligament (3D proliferation)
Cell proliferation of ACL fibroblasts onto the LARS ligament was assessed. Cells from passage 3–7
were seeded at 105cells/LARS ligament piece. Then samples were incubated overnight at 37◦C, 5%
CO2and 95% humidity, to improve cell adhesion. Seeded samples were then recovered with DMEM
10% FBS. Medium were changed every 3 days.
After 7, 14, 21, 28 and 35 days of culture, cells were detached from LARS ligament with trypsin
(0.05%) collagenase (0.025%) [15] and counted with a Coulter counter system (Beckman Coulter) to
assess cell proliferation: cells harvested were resuspended in DMEM 10% SVF and counted with the
coulter counter system.
3.4. Giemsa staining
After 7, 14, 21 and 28 days cells seeded ligament were rinsed in PBS and fixed in 4% paraformalde-
hyde for 48 h. Seeded scaffold were then stained with Giemsa for 15 min and washed twice in distilled
water before observation under transmitted light.
3.5. Immunodetection of collagen I and decorin
In this work we also investigate the secretion of matrix components by fibroblasts seeded onto the scaf-
fold. Seeded scaffold were first fixed in 4% paraformaldehyde for 48 h, dehydrated and then embedded
in paraffin. Serial tissue sections of 7 µm thick were done with a manual microtome and indirect im-
munodetection were conducted. Briefly, paraffin-embedded sections were deparaffinized and hydrated
through xylene and a graded series of alcohol. Sections were rinsed for 10 min in phosphate buffer
sodium (PBS). Endogenous peroxidase activity was blocked by incubation in 3% (v/v) H2O2for 5 min.
Scaffold sections were washed in PBS for 10 min, incubated for 20 min at 37◦C with goat serum (10%)
or non-fat milk (1%) diluted in a PBS Tween (0.05%) BSA (1%) solution. Scaffold sections were then
incubated for 30 min with a primary polyclonal antibody against collagen type I (1/50 dilution; TEBU-
BIO) or decorin (1/20 dilution, R and D systems), in PBS and then washed three times for 5 min in PBS.
The absence of primary antibody was used as a blank, and controls were performed using non-immune
mouse serum. Sections were then incubated with secondary antibody (anti-rabbit IgG or anti-goat IgG)
conjugated with peroxidase (Amersham Biosciences) for 30 min and were then washed three times for
5 min in PBS and in Tris-HCl buffer. Sections were then incubated in peroxidase substrate solution (di-
aminobenzidine) in a dark chamber for 20 min, rinsed in distilled water (twice for 5 min), cleared and
mounted for observation under a light microscope.
3.6. Scanning electron microscopy
After cell culture, samples were fixed in 4% paraformaldehyde for 48 h, and conserved in 70% ethanol
until analysis. LARS scaffold surfaces were investigated using an environmental scanning electron mi-
croscope (Hitachi TM3000, Japan). The microscope was operated at 12–25 kV under a 10−4–10−5Tor r
vacuum. Images were acquired and were visualized on a computerized digital imaging system magnifi-
cation ×250 and ×1.0k, observation conditions: 15 kV, observation mode: standard mode, image mode:
COMPO, room temperature: 18◦C.
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4. Results
4.1. Proliferation of fibroblasts from ruptured ACL in 3D culture
All cells strains proliferate on the scaffold as illustrated in Fig. 1. The three cells strain did not have
the same rate of proliferation. Nevertheless, for each strain there is no significative variation regardless
the surface of the biomaterial considered: grafting does not altered cell proliferation.
4.2. Cell organization and localization
Giemsa staining shows cell localization. Cells on both, non grafted and grafted scaffolds, are longi-
tudinally oriented. Their density increased during the culture (data not shown). At 14 days of culture,
difference of cells organization between grafted and non grafted scaffold are visible. On non-grafted
scaffold, cells were localised at the periphery of the bundles and surround them (Fig. 2(a)). On grafted
scaffold, cells were not only at the periphery of the bundles but also inside bundles and around fibers
(Fig. 2(b)).
4.3. Immunodetection of collagen I
Immunoperoxydase labeling of collagen I revealed a positive staining on non-grafted as well as on
grafted scaffold starting from 7 days of culture (data not shown).
Fig. 1. Human fibroblasts ligament proliferation in 3D culture. (Colors are visible in the online version of the article;
http://dx.doi.org/10.3233/BME-130753.)
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Fig. 2. Giemsa staining of seeded ungrafted (a) and grafted (b) PET after 14 days of culture. Black arrows: cell nuclei; white
arrows: fibers. (The colors are visible in the online version of the article; http://dx.doi.org/10.3233/BME-130753.)
Fig. 3. Collagen I labelling after 28 days of culture in ungrafted (a) and grafted (b) PET. Black arrows: collagen I labelling;
white arrows: fibers.
At 28 days (Fig. 3) staining was localized both at the periphery of bundles and inside the scaffold
structure. On non-grafted scaffold, collagen I was localized at the periphery of bundles (Fig. 3(a)). On
grafted scaffold, collagen I seems to be more abundant at the periphery and present a sheet-like structure
(Fig. 3(b)).
4.4. Decorin immunodetection
Decorin was detected only at 28 days of culture. At this time of culture, decorin labelling is weakly
expressed both on non-grafted (Fig. 4(a)) and grafted scaffolds (Fig. 4(b)). However on non-grafted
scaffolds, decorin were localized only at the periphery of bundles while on grafted scaffolds, decorin
were also observed around fibers.
4.5. Scanning electron microscopy
Non-grafted and grafted scaffolds after seeding were investigated at 14 days of culture by scanning
electron microscopy. At low magnification both non grafted and grafted scaffolds bundles appeared
covered by cells. On non-grafted scaffold, cells are only at the periphery of bundles linking superficial
fibers (Fig. 5(a), (b), (c)). On grafted scaffold, cells are not only localized at the periphery of bundles but
also inside, between fibres (Fig. 5(d), (e), (f)). Interspaces between fibers of bundles were observed at
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Fig. 4. Decorin labelling after 28 days of culture on ungrafted (a) and grafted (b) PET. Black arrows: decorin labelling; white
arrows: fibers.
magnification ×250 (Fig. 5(b), (e)) and ×2.0k (Fig. 5(c), (f)). Cells were interconnect with neighbouring
fibers and seemed to synthesize an extracellular matrix (ECM). Whatever the surface cells have a semi-
ovoid or spindle-shape morphology.
5. Discussion/conclusion
The LARS ligament was used as a new generation of artificial ligament because of its innovative de-
sign. Its successful application in ACL reconstruction was reported in the current literature at short term
[10,16,17]. Nevertheless, one study had reported potential risks of late graft failure [18] and other stud-
ies pointed osteoarthritis development [19–22]. Moreover, a recent article reported a case of synovitis
and the presence of a thick fibrous scar tissue around the graft and a poorly organized scar tissue infil-
trated into the graft [23]. This study demonstrated the importance of deeper investigation concerning the
cellular response and the need to improve the biocompatibility of this material.
So, to enhance biocompatibility, our laboratory has developed a new bioactive PET ligament prosthe-
sis by grafting a bioactive polymer, poly(sodium styrene sulfonate) (poly(NaSS)), onto LARS prosthe-
sis surface [4]. We have shown that surface grafting of a bioactive polymer (pNaSS) on a polyethylene
terephtalate (PET) device which is used for ACL reconstruction in clinical situations optimizes the adhe-
sion and the distribution of human and sheep fibroblasts in culture [5,14]. After 3 months of implantation
in the sheep, clinical observations show a better functional recuperation with this modified ligament.
To investigate mechanisms responsible of a better biocompatibility of LARS grafted prosthesis in
vivo, behaviour of fibroblasts from ruptured human ACL was investigated in vitro. Fibroblasts derived
from human ruptured ACL were successfully seeded on both non-grafted and grafted PET scaffolds and
we evaluate cell proliferation, organization and matrix deposit.
In the present study, we demonstrated that human ligament fibroblasts adhere and proliferate both
on non-grafted and grafted scaffold with no significative difference. However concerning the adhesion
process, a previous study from Zhou et al. [6,7] has shown that cell adhesion of human fibroblast cells
McCoy is dependant of the chemistry of the surface. Thus grafting polyNaSS at the surface of LARS
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Fig. 5. Fibroblasts organization on LARS prosthesis after 14 days of culture. Black arrows: fibers; white arrows: cells.
ligament improves cell adhesion morphology and increase cell adhesion strength. This previous study
was conducted on short time (4 days of culture) unlike this present study which established first obser-
vation at 7 days, demonstrating that grafting influence cell adhesion morphology during the first days of
culture. Let us point out that another preliminary work from Trieb and colleagues [11] using, fibroblasts
isolated from tractus iliotibialis tissue from hip surgery and osteoblast-like cells MG63 demonstrated
cell adhesion on unmodified LARS ligament.
Hence, here we demonstrate that there is no significative cell proliferation difference whatever the
surfaces, but we point that each cell strain present its own proliferation rate (Fig. 1). This variation is
probably due to the age of donor or the length of rupture. This hypothesis is under investigation.
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Observations after Giemsa staining are confirmed by scanning electron microscopy. We show that on
grafted surfaces cells not only build a capsule around bundles as shown by Trieb et al. [11] but also
penetrate inside bundles, surround individual fibers and are aligned longitudinally along the length of
fibers (Figs 2 and 5). These results is probably due to the sulfonate groups which conferred hydrophilic
properties and specificity to the grafted PET surface which characteristic can explain the best results
observed in vitro or in vivo when PET was grafted by enhancing adsorption of plasma proteins before
cells adhesion on biomaterial and could promote proliferation [1,24].
In all tested surfaces, cells are able to synthesize collagen type I, which is the major collagen of
ligaments and tendon [25] (Fig. 3). Brune and colleagues show first no significant difference in the gene
expression of collagen I between fibroblasts extracted from intact and ruptured ACL and second that
collagen I is widely distributed through the tissue in the ECM of the ACL fibroblast seeded in an animal
model of porcine small intestinal submucosal extracellular matrix [26]. This would be consistent with the
study conducted by Zhou et al., showing no significative difference in collagen I expression, by RT-PCR
between unmodified and bioactivated ligament [6]. Immunodetection of collagen I in the present study
shows the presence of collagen I on both surfaces. However, on grafted ligament, collagen I is more
organized, presenting a waviness appearance with fibrils oriented parallel to the longitudinal axis of the
prosthesis as seen in the natural ligament in vivo [25]. So, it seems that grafting enhance organisation of
collagen I at cell surface and it would be of great interest to quantify secreted collagen and to explore in
our condition of grafting the expression of collagen I.
Finally, we have also studied decorin, a small leucine-rich proteoglycan interacted with several ma-
trix molecules, including various types of collagen. Decorin plays a critical role in the organization of
collagen fibrils. Häkkinen and colleagues demonstrated that abnormal expression of decorin might re-
veal abnormal morphology and organization of the collagen fibrils in the periodontal ligament [27–29].
Our results show that decorin was differently distributed throughout the non grafted and grafted scaffold
(Fig. 4). In fact decorin labelling follows that of collagen I on both surfaces, according to it function in
collagen organization [29].
To conclude, in vitro results contribute to explain the better “bio-integration” observed with polyNaSS
grafted ligament in vivo in animal [30]. In fact, cell proliferation and colonization are key parameters
for biointegration of the prosthesis. In our study, we have shown that grafting does not significantly
influence cell proliferation; however it enhances cell organisation and favours collagen and decorin de-
posits around fibers. We will investigate the secretion and the organisation of collagen III and the surface
expression of integrin.
References
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... This is a very challenging condition to meet because short-term cell adhesion and long-term growth capacities are depending on many factors, deriving principally from the nature of the fiber surface. If its surface is not functionalized, most of the polymers exhibit poor capacities of cell fibroblasts colonization [2,6] . Thus, several proposals have failed, however the ones consisting of fabrics and fibers miming of the natural ligament structure brought new solutions to the field [1] . ...
... Amongst various biodegradable polyesters, polycaprolactone (PCL) responds to the most requirements such as mechanical properties, non-cytotoxicity, and long-term degradation [8,9] . Moreover, the PCL surfaces properties can be adapted to the application, as the presence of a poly(sodium styrene sulfonate)-grafted (PNaSS) layer on the surface improves its biological response [6,10,11] shown to improve cell adhesion [6] . With this aim, PNaSS has been grafted on PCL surfaces (films, fibers, and fabrics) leading to a positive influence on the cell behavior and activity in vitro and in vivo [6,12] . ...
... Amongst various biodegradable polyesters, polycaprolactone (PCL) responds to the most requirements such as mechanical properties, non-cytotoxicity, and long-term degradation [8,9] . Moreover, the PCL surfaces properties can be adapted to the application, as the presence of a poly(sodium styrene sulfonate)-grafted (PNaSS) layer on the surface improves its biological response [6,10,11] shown to improve cell adhesion [6] . With this aim, PNaSS has been grafted on PCL surfaces (films, fibers, and fabrics) leading to a positive influence on the cell behavior and activity in vitro and in vivo [6,12] . ...
Correlating degradation of functionalized polycaprolactone fibers and fibronectin adsorption using atomic force microscopy
Article
  • Nov 2021
  • POLYM DEGRAD STABIL
In previous studies, a bioactive ligament prosthesis made of poly (ethylene terephthalate) and functionalized with sulfonate groups was proposed by our group for the reconstruction of injured ligaments. In vitro and in vivo experiments allowed elucidating the mechanism at the origin of the bioactivity of those prostheses, which involves fibronectin adsorption. As the subject evolves the next challenge was to elaborate a bioactive and biodegradable ligament able to maintain the bioactivity along with the degradation process. Polycaprolactone is the biodegradable polymer of choice for such application, due to its ability to degrade in the body environment without releasing cytotoxic by-products. To follow the evolution of the bioactivity of polycaprolactone, fibronectin adsorption, morphology, and mechanical properties on unmodified and functionalized surfaces were assessed using AFM techniques after real-time degradation under physiological conditions. The results showed that the hydrolytic degradation strongly occurred on functionalized fiber with 8.9 × 10⁻³ w⁻¹ of degradation rate and half-life time 78 weeks. The degradation also affected to the conformation of fibronectin with the presence of protein aggregation on 72 weeks of degraded functionalized fiber.
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... [18][19][20] In particular, the development of grafting poly(sodium styrene sulfonate) (pNaSS) on polyethylene terephthalate (PET) LARS™ ligaments led to a new generation of biointegrable and bioactive synthetic ligaments. [21][22][23] The excellent in vitro and in vivo results in a large animal model (i.e., sheep) demonstrated that the pNaSS grafting provided (1) an increase in the cell adhesion strength; 22 (2) a better morphology of the cells that were more spread out and more homogeneously distributed; [23][24][25] (3) an increase in type-I collagen production that was accompanied by tissue formation with a better organization; 24,26 (4) an improved osteointegration of prosthesis with the generation of a good bone-implant interface. 27 Based on that, the idea to develop the next generation of synthetic ligaments which could be biointegrable, bioactive, and biodegradable emerged. ...
... [18][19][20] In particular, the development of grafting poly(sodium styrene sulfonate) (pNaSS) on polyethylene terephthalate (PET) LARS™ ligaments led to a new generation of biointegrable and bioactive synthetic ligaments. [21][22][23] The excellent in vitro and in vivo results in a large animal model (i.e., sheep) demonstrated that the pNaSS grafting provided (1) an increase in the cell adhesion strength; 22 (2) a better morphology of the cells that were more spread out and more homogeneously distributed; [23][24][25] (3) an increase in type-I collagen production that was accompanied by tissue formation with a better organization; 24,26 (4) an improved osteointegration of prosthesis with the generation of a good bone-implant interface. 27 Based on that, the idea to develop the next generation of synthetic ligaments which could be biointegrable, bioactive, and biodegradable emerged. ...
Long-term hydrolytic degradation study of polycaprolactone films and fibers grafted with poly(sodium styrene sulfonate): Mechanism study and cell response
Article
  • Nov 2020
Polycaprolactone (PCL) is a widely used biodegradable polyester for tissue engineering applications when long-term degradation is preferred. In this article, we focused on the analysis of the hydrolytic degradation of virgin and bioactive poly(sodium styrene sulfonate) (pNaSS) functionalized PCL surfaces under simulated physiological conditions (phosphate buffer saline at 25 and 37 °C) for up to 120 weeks with the aim of applying bioactive PCL for ligament tissue engineering. Techniques used to characterize the bulk and surface degradation indicated that PCL was hydrolyzed by a bulk degradation mode with an accelerated degradation—three times increased rate constant—for pNaSS grafted PCL at 37 °C when compared to virgin PCL at 25 °C. The observed degradation mechanism is due to the pNaSS grafting process (oxidation and radical polymerization), which accelerated the degradation until 48 weeks, when a steady state is reached. The PCL surface was altered by pNaSS grafting, introducing hydrophilic sulfonate groups that increase the swelling and smoothing of the surface, which facilitated the degradation. After 48 weeks, pNaSS was largely removed from the surface, and the degradation of virgin and pNaSS grafted surfaces was similar. The cell response of primary fibroblast cells from sheep ligament was consistent with the surface analysis results: a better initial spreading of cells on pNaSS surfaces when compared to virgin surfaces and a tendency to become similar with degradation time. It is worthy to note that during the extended degradation process the surfaces were able to continue inducing better cell spreading and preserve their cell phenotype as shown by collagen gene expressions.
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... Third generation designs exploited further surface functionalizing of the PET ligament prosthesis with grafted bioactive polymers to improve biocompatibility and tissue "bio-integration", i.e. increased host cell adhesion, proliferation and signaling to stabilize implant integration [10,11]. Migonney et al. showed that poly(sodium 4-styrene sulfonate) (PNaSS) grafting onto PET surfaces improves both adhesion and functions of broblast cells that constitute ligament and tendon endogenous cells [10][11][12][13][14]. ...
... Prior to surface functionalization of polymers bers or fabrics, a surface pre-treatment called spin nish removal (SFR) is usually performed using Soxhlet solvent extraction to remove the protective spin nish oil [22]. SFR is required for PNaSS "grafting from" reactions on clean PET ber surfaces through radical grafting polymerization processes [10][11][12][13][14]. ...
Influence of Spin Finish on Degradation, Functionalization and Long-term Storage of Polyethylene Terephthalate Fabrics Dedicated to Ligament Prostheses
Preprint
Full-text available
  • Aug 2020
Spin finish oil applied to poly(ethylene terephthalate) (PET) fibers is shown to alter the surface properties of commercial PET fibers in storage over extended storage times. Oil removal by solvent extraction as required for their applications is shown to be changed; fiber surface chemistry, particularly surface functionalization with anionic polymer grafts, is altered, and surface mechanical properties are altered. Spin finish oxidation in storage is proposed to produce these fiber changes in storage important to their biomedical performance. Background: Poly(ethylene terephthalate) (PET) fabrics surface-functionalized using anionic polymer grafts to enhance their biocompatibility, cell adhesion, proliferation and functional performance as PET ligament prostheses have been developed for medical application in vascular and ligament prostheses. Here, we provide new evidence for deleterious effects of uncontrolled storage times and conditions on the final properties of PET medical fabrics and devices, specifically alteration and degradation of applied spin finish oil and fabric fiber surface properties, and limits to surface functionalization of PET fibers important to for medical uses. Results: Textile spin finish oil effects from 2- to 25-year storage times on PET fiber degradation and surface functionalization with anionic polymers were analyzed using FTIR, DSC and by quantitative AFM nano-mechanical profiling. Degradation of the spin-finish oil/fiber interface reduced oil Soxhlet extraction efficiency due to oil solubility changes in diethyl ether or n-hexane extraction solvents. However, solvent tetrahydrofuran was shown to be the most efficient extraction solvent even after long fabric storage times, facilitating further efficient surface functionalization of PET fabrics. Surface mechanical properties of PET fibers and fabrics over storage times spanning 2 to 25 years were investigated by using AFM-Peakforce QNM. Results showed significant and dramatic reduction of the surface elastic modulus of degraded PET fiber surfaces, with surface stiffness decreasing from 2.3 GPa for optimal (2-year) conditions of storage (PET 2018) to 50-85 MPa for extended storage (to 25 year) periods (PET2009 and PET1993). Conclusion: The ambient aging of textile spin finish oil with PET surfaces was shown to induce PET surface degradation, limiting oil removal, limiting further PET fiber surface graft functionalization, and compromising mechanical properties. Moreover, residual degraded finishing oils likely contained oxidation products from extended storage that alter PET fabrics.
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... Due to the limited healing capacity of the ACL, a number of therapeutic options have been developed to restore its functions in the knee, including non-operative conservative treatments (immobilization/bracing/rest, exercise/physiotherapy, corticoid injection, etc.) and surgical procedures (ACL reconstruction, i.e., ligamentoplasty), while primary repair (suturing) was abandoned due to high rates of failure (40-100%) [2,11,12,[17][18][19][20][21][22][23]37,60]. ACL reconstruction has been widely adopted as a standard procedure, especially for young patients, based on the use of both natural/biological grafts including autografts (patellar, hamstring, or quadriceps tendons) and allografts (frozen ligaments from cadavers), as well as commercially available synthetic or artificial materials and systems (substitutes, graftaugmented, and prosthetic devices) (Gore-Tex ® -polytetrafluoroethylene-prosthesis; Lars ® ligament-terephthalic polyethylene polyester; Stryker-Dacron ® ligament-polyethylene terephthalate; Leeds-Keio ® -polyester ethylene terephthalate; Kennedy ligament-augmentation device-LAD-braided polypropylene braid) [2,17,18,[22][23][24][25][26][27][28][29]37,43,46,60,105,122]. While autografts display several advantages (good initial mechanical strength, adapted to promote cell proliferation and neotissue formation), their use is restricted by their limited availability, the necessity for second surgery for tissue harvest, the problem of donor site morbidity resulting in pain/contracture/weakness, and a lack of fully adequate mechanical strength over time [2,17,18,22,23,37,46,60]. ...
Advanced Gene Therapy Strategies for the Repair of ACL Injuries
Article
Full-text available
  • Nov 2022
  • INT J MOL SCI
The anterior cruciate ligament (ACL), the principal ligament for stabilization of the knee, is highly predisposed to injury in the human population. As a result of its poor intrinsic healing capacities, surgical intervention is generally necessary to repair ACL lesions, yet the outcomes are never fully satisfactory in terms of long-lasting, complete, and safe repair. Gene therapy, based on the transfer of therapeutic genetic sequences via a gene vector, is a potent tool to durably and adeptly enhance the processes of ACL repair and has been reported for its workability in various experimental models relevant to ACL injuries in vitro, in situ, and in vivo. As critical hurdles to the effective and safe translation of gene therapy for clinical applications still remain, including physiological barriers and host immune responses, biomaterial-guided gene therapy inspired by drug delivery systems has been further developed to protect and improve the classical procedures of gene transfer in the future treatment of ACL injuries in patients, as critically presented here.
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... Due to the limited healing capacity of the ACL, a number of therapeutic options have been developed to restore its functions in the knee, including non-operative conservative treatments (immobilization/bracing/rest, exercise/physiotherapy, corticoid injection, etc.) and surgical procedures (ACL reconstruction, i.e., ligamentoplasty), while primary repair (suturing) was abandoned due to high rates of failure (40-100%) [2,11,12,[17][18][19][20][21][22][23]37,60]. ACL reconstruction has been widely adopted as a standard procedure, especially for young patients, based on the use of both natural/biological grafts including autografts (patellar, hamstring, or quadriceps tendons) and allografts (frozen ligaments from cadavers), as well as commercially available synthetic or artificial materials and systems (substitutes, graftaugmented, and prosthetic devices) (Gore-Tex ® -polytetrafluoroethylene-prosthesis; Lars ® ligament-terephthalic polyethylene polyester; Stryker-Dacron ® ligament-polyethylene terephthalate; Leeds-Keio ® -polyester ethylene terephthalate; Kennedy ligament-augmentation device-LAD-braided polypropylene braid) [2,17,18,[22][23][24][25][26][27][28][29]37,43,46,60,105,122]. While autografts display several advantages (good initial mechanical strength, adapted to promote cell proliferation and neotissue formation), their use is restricted by their limited availability, the necessity for second surgery for tissue harvest, the problem of donor site morbidity resulting in pain/contracture/weakness, and a lack of fully adequate mechanical strength over time [2,17,18,22,23,37,46,60]. ...
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... SFR oil removal extracts an excessive amount of mass from these aged fiber samples (Figs. 1,2,3,4,13), indicating that the imbibed oxidized finishing oil plus any degraded PET oil-soluble products are extracted from these oil-swollen PET fabrics under SFR (Fig. 3A). ...
Influence of spin finish on degradation, functionalization and long-term storage of polyethylene terephthalate fabrics dedicated to ligament prostheses
Article
Full-text available
  • Feb 2021
Polyethylene terephthalate (PET) fibers and fabrics are widely used for medical device applications such as vascular and anterior cruciate ligament prostheses. Several years ago, we began functionalizing PET fabrics using anionic polymers to enhance their biocompatibility, cell adhesion, proliferation and functional performance as PET ligament prostheses. Polymer functionalization followed a grafting-from process from virgin PET surfaces subject to spin-finish oil additive removal under Soxhlet extraction to remove residual fiber manufacturing oil. Nevertheless, with increasing time from manufacture, PET fabrics stored without a spin finish removal step exhibited degradation of spin finish oil, leading to (1) incomplete surface cleaning, and (2) PET surface degradation. Moreover, oxidizing agents present in the residual degraded oil prevented reliable functionalization of the prosthesis fibers in these PET fabrics. This study compares effects of PET fabric/spin finish oil storage on PET fabric anionic polymer functionalization across two PET fabric ligament storage groups: (1) 2-and 10-year old ligaments, and (2) 26-year old ligaments. Strong interactions between degraded spin finish oil and PET fiber surfaces after long storage times were demonstrated via extraction yield; oil chemistry changed assessed by spectral analysis. Polymer grafting/functionalization efficiency on stored PET fabrics was correlated using atomic force microscopy, including fiber surface roughness and relationships between grafting degree and surface Young's modulus. New PET fabric Young's modulus significantly decreased by anionic polymer functionalization (to 96%, grafting degree 1.6 µmol/g) and to reduced modulus and efficiency (29%) for 10 years storage fabric (grafting degree ~ 1 µmol/g). As fiber spin finish is mandatory in biomedically applicable fiber fabrication, assessing effects of spin finish oil on commercial polymer fabrics after longer storage under various conditions (UV light, temperature) is necessary to understand possible impacts on fiber degradation and surface functionalization. Abbreviations AFM Atomic force microscopy DE Diethyl ether DSC Differential scanning calorimetry FTIR Fourier transform infrared spectroscopy PET Polyethylene terephthalate NaSS/pNaSS Sodium 4-styrene sulfonate/poly(sodium 4-styrene sulfonate) SFR Spin finish removal OPEN
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... Its use in ACL reconstruction as an isolated graft is contraindicated because it has failed in the majority of the cases even though it seemed successful in the shortterm [14][15][16][17]26,37,41,64] . The difference in PCL reconstruction is that the function of the graft in the acute phase is to acts as the central support system, allowing the PCL remnants to heal in the correct position with minimal posterior laxity in the knee [30,31,34,65] . Another advantage of the artificial graft is that there is no need for intensive postoperative rehabilitation using sophisticated devices. ...
Complex knee injuries treated in acute phase: Long-term results using Ligament Augmentation and Reconstruction System artificial ligament
Article
Full-text available
  • Mar 2018
AIM To present the long-term results of complex knee injuries, treated early using the Ligament Augmentation and Reconstruction System (LARS) artificial ligament to reconstruct posterior cruciate ligament (PCL). METHODS From September 1997 to June 2010, thirty-eight complex knee injuries were treated, where early arthroscopic PCL reconstructions were undergone, using the LARS (Surgical Implants and Devices, Arc-sur-Tille, France) artificial ligament. Exclusion criteria were: Late (> 4 wk) reconstruction, open technique, isolated PCL reconstruction, knee degenerative disease, combined fracture or vascular injury and use of allograft or autograft for PCL reconstruction. Clinical and functional outcomes were assessed with IKDC Subjective Knee Form, KOS-ADLS questionnaire, Lysholm scale and SF-12 Health Survey. Posterior displacement (PD) was measured with the Telos Stress Device. RESULTS Seven patients were excluded; two because of co-existing knee osteoarthritis and the remaining five because of failure to attend the final follow-up. The sample consisted of 31 patients with mean age at the time of reconstruction 33.2 ± 12.5 years (range 17-61). The postoperative follow-up was on average 9.27 ± 4.27 years (range 5-18). The mean average IKDC and KOS scores were 79.32 ± 17.1 and 88.1 ± 12.47% respectively. Average PD was 3.61 ± 2.15 mm compared to 0.91 ± 1.17 mm in the uninjured knees (one with grade 1 + and two with grade 2 +). Dial test was found positive in one patient, whereas the quadriceps active drawer test was positive in three patients. None was tested positive on the reverse-pivot shift test. The range of motion (ROM) was normal in thirty knees, in comparison with the contralateral one. There was no extension deficit. Osteoarthritic changes were found in three knees (9.6%). CONCLUSION Early treatment of complex knee injuries, using LARS artificial ligament for PCL reconstruction sufficiently reduces posterior tibia displacement and provides satisfactory long-term functional outcomes.
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Phytic acid/magnesium ion complex coating on PEEK fiber woven fabric as an artificial ligament with anti-fibrogenesis and osteogenesis for ligament-bone healing
Article
  • Aug 2022
Development of an artificial ligament possessing osteogenic activity to enhance ligament-bone healing for reconstruction of anterior cruciate ligament (ACL) is a great challenge. Herein, polyetheretherketone fibers (PKF) were coated with phytic acid (PA)/magnesium (Mg) ions complex (PKPM), which were woven into fabrics as an artificial ligament. The results demonstrated that PKPM with PA/Mg complex coating exhibited optimized surface properties with improved hydrophilicity and surface energy, and slow release of Mg ions. PKPM significantly enhanced responses of rat bone marrow stem cells in vitro. Moreover, PKPM remarkably promoted M2 macrophage polarization that upregulated production of anti-inflammatory cytokine while inhibited M1 macrophage polarization that downregulated production of pro-inflammatory cytokine in vitro. Further, PKPM inhibited fibrous encapsulation by preventing M1 macrophage polarization while promoted osteogenesis for ligament-bone healing by triggering M2 macrophage polarization in vivo. The results suggested that the downregulation of M1 macrophage polarization for inhibiting fibrogenesis and upregulation of M2 macrophage polarization for improving osteogenesis of PKPM were attributed to synergistic effects of PA and sustained release of Mg ions. In summary, PKPM with PA/Mg complex coating upregulated pro-osteogenic macrophage polarization that supplied a profitable anti-inflammatory environments for osteogenesis and ligament-bone healing, thereby possessing tremendous potential for reconstruction of ACL.
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Analysis of early cellular responses of anterior cruciate ligament fibroblasts seeded on different molecular weight polycaprolactone films functionalized by a bioactive poly(sodium styrene sulfonate) polymer
Article
  • Jul 2019
With the growing number of anterior cruciate ligament (ACL) ruptures and the increased interest for regenerative medicine procedures, many studies are now concentrated on developing bioactive and biodegradable synthetic ligaments. For this application, the choice of raw materials with appropriate physicochemical characteristics and long-term degradation features is essential. Polycaprolactone (PCL) has the advantage of slow degradation that depends on its molecular weight. This study evaluates two PCL materials: a technical grade (PC60: 60 kDa) versus a medical grade (PC12: 80 kDa), both before and after functionalization with poly(sodium styrene sulfonate) (pNaSS). After determining the grafting process had little to no effect on the PCL physicochemical properties, sheep ACL fibroblast responses were investigated. The PC12 films induced a significantly lower expression of the tumor necrosis factor alpha inflammatory gene compared to the PC60 films. Both film types induced an overproduction of fibroblast growth factor-2 and transforming growth factor beta compared to the controls on day 5 and demonstrated collagen gene expression profiles similar to the controls on day 7. Upon protein adsorption, pNaSS grafting caused a rapid cell adhesion in the first 30 min and an increased adhesion strength (1.5-fold higher). Moreover, after 7 days, an increase in cell density and actin network development were noted on the grafted films.
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Ligart : ligament synthétique « bioactif » et « biointégrable » permettant la réhabilitation rapide du patient : greffage chimique, évaluations biologiques in vivo, expérimentation animale, étude préclinique
Article
Full-text available
  • Apr 2011
Ligart project aimed to propose a new generation of artificial ligament which can be considered as “bioactive” and “biointegrable” destined to be used in anterior cruciate ligament (ACL) reconstruction surgery of patients with knee ACL rupture frequently related to contact and pivoting sports. Such bioactive ligament will allow preventing hostile host response due to the presence of a bioactive polymer grafted on its surface. The LARS prosthetic ligament made of poly (ethylene terephtalate) is chemically grafted by a “bioactive” and “biomimetic” polymer, which will allow masking the synthetic origin of the material and controlling collagen secretion, fibroblasts proliferation and inflammatory response. The bioactive ligament can be considered as “biointegrated”, i.e. integrated by the living system: it induces controlled fibroblast cell proliferation and colonization along the PET fibres of the joint part of the prosthetic ligament, ensure and/or steady appropriate mechanical behaviour of the ligament which can be compared to that of the biological ACL, decrease the inflammatory response and prevent acute synovites extensively described in the case of the first generation of synthetic ligament. Fifty-six sheep divided in two series devoted to the evaluation of (1) the biological response (histology, molecular biology, SEM) and (2) the biomechanical behaviour were implanted with bioactive polymer grafted or commercial ACL for 3 or 12 months. Results show that the grafting of PET ligament by the bioactive polymer sensitively improves the biological response at 3 and 12 months. Preclinical study in dog has started and experiments on human are scheduled in the next future.
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Évaluation clinique et biologique d’un ligament synthétique bioactif chez la brebis
Article
Full-text available
  • Sep 2009
The anterior cruciate ligament, which plays a key role in the knee stabilization, is commonly injured mainly during sport practicing such as soccer or skiing. Although it seems that ligament replacement by a tendon autograft is a better solution, the reconstruction with an artificial ligament provides a shorter recovery time. Polyethylene terephthalate (PET) is the best polymer to fabricate ligament prosthesis but its biocompatibility still needs to be improved. Radical graft polymerization of sodium salt of styrene sulfonate (NaSS) on PET surface was performed using the “grafting from” technique. The grafting ratio is about 5μmol/g and found to be perfectly reproducible. Polymer grafted ligaments and non-grafted ligaments were implanted in sheep for a 3-month observation. The clinical and biological evaluation of the knee synovial liquid of implanted sheep evidenced an early functional recuperation and an excellent tolerance of pNaSS reflecting a significant absence of articular inflammation.
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Grafting of dermatan sulfate on polyethylene terephtalate to enhance biointegration
Article
Full-text available
  • Jul 2011
  • J BIOMED MATER RES A
The aim of the present study was to achieve the immobilization of dermatan sulfate (DS) on polyethylene terephthalate (PET) surfaces and to evaluate its biocompatibility. DS obtained from the skin of Scyliorhinus canicula shark was immobilized via carbodiimide on knitted PET fabrics, modified with carboxyl groups. PET-DS characterization was performed by SEM, ATR-FTIR and contact angle measurements. Biocompatibility was evaluated by investigating plasma protein adsorption and endothelial cell proliferation, as well as by subcutaneous implantations in rats. The results indicated that DS immobilization on PET was achieved at ~8 μg/cm². ATR-FTIR evidenced the presence of sulfate groups on the PET surface. In turn, contact angle measurements indicated an increase in the surface wettability. DS immobilization increased albumin adsorption on the PET surface, whereas it decreased that of fibrinogen. In vitro cell culture revealed that endothelial cell proliferation was also enhanced on PET-DS. Histological results after 15 days of subcutaneous implantation showed a better integration of PET-DS samples in comparison to those of nonmodified PET. In summary, DS was successfully grafted onto the surface of PET, providing it new physicochemical characteristics and biological properties for PET, thus enhancing its biointegration.
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Early results of the Leeds-Keio anterior cruciate ligament replacement
Article
  • May 1991
We report the two- to four-year results following the insertion of the Leeds-Keio prosthetic ligament for chronic anterior cruciate deficiency. Virtually all the 20 patients were less disabled by instability, but objective results were good or excellent in only two-thirds and under anaesthesia the pivot shift sign was still positive in half. Arthroscopic and histological assessment in 16 patients failed to show the development of a functional neoligament, and the common appearance of a synovitic reaction to polyester particles gave concern.
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Ligament Advanced Reinforcement system anterior cruciate ligament reconstruction
Article
  • Jul 1995
  • OPER TECHN SPORT MED
The problem of the anterior cruciate ligament (ACL) deficient knee and its reconstruction is far from being completely solved. In this article, I would like to discuss the use of a new generation synthetic ligament, the ligament advanced reinforcement system, which is made of polyester. A special knitted structure in the body of the ligament is used with open fibers in the central intra-articular portion of the ligament to allow substantial tissue ingrowth.
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Surface modification of polyethylene terephthalate with albumin and gelatin for improvement of anticoagulation and endothelialization
Article
  • Nov 2008
  • APPL SURF SCI
The surfaces of polyethylene terephthalate (PET) were modified by oxygen plasma-induced and ultraviolet (UV)-assisted acrylic acid (AAc) grafting polymerization, and the carboxyl (COOH) groups on the PET surface was 5.29 × 10−9mol/cm2. Then using the COOH as reacting sites, the molecules of gelatin and bovine serum albumin (BSA) were further co-immobilized on the PET surface. The modified PET surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and surface chemical quantitative analysis. The results showed that the molecules of gelatin and albumin were immobilized on the PET surface. The concentration of gelatin on the gelatin-immobilized PET surface was 2.02 μg/cm2. For the gelatin-immobilized PET surface, the human umbilical vein endothelial cells (HUVECs) culture attachment and proliferation ratios were improved, but the anticoagulation became worse proved by platelet adhesion test in vitro and the lactate dehydrogense (LDH) test. After further co-immobilization of albumin with gelatin biomolecules on the PET surface (PET-Gel–BSA), the percent of platelet adhesion in vitro decreased 28% than that on the gelatin-immobilized PET surface, and the cell density on the PET-Gel–BSA film (1.08 × 105 cells/cm2) was significantly higher than that on the control PET surface. This investigation tries to find a method which can construct the anticoagulant surface before the endothelium formation and also accelerate the endothelialization of polymer surface.
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Patient satisfaction needs as related to knee stability and objective findings after ACL reconstruction using the LARS artificial ligament
Article
  • Aug 2000
The purposes of this study are to compare patient satisfaction with the objective measurement of knee stability and assess early complications following ACL reconstruction using a LARS artificial ligament. Forty-seven patients were reviewed 8–45 months after surgery. Assessment was made by the Knee and Osteoarthritis Outcome Score for patient satisfaction, a modified International Knee Documentation Committee form for clinical knee stability, and a Telos stress radiography for PA stability. Complications were assessed at interview and were double-checked with charts. The LARS artificial ligament may be a safe device to reconstruct an ACL tear. Documenting mechanical stability of the knee is inadequate when reporting follow-up studies and a questionnaire assessing patient satisfaction should be added to provide a better picture of the outcome and results.
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Biologic Failure of a Ligament Advanced Reinforcement System Artificial Ligament in Anterior Cruciate Ligament Reconstruction: A Report of Serious Knee Synovitis
Article
  • Feb 2012
  • ARTHROSCOPY
A ligament advanced reinforcement system (LARS) artificial ligament has been proposed for use in anterior cruciate ligament reconstruction in some cases, and an emerging body of reports has shown its success in the short term. However, there are great concerns about the potential risks of complications, which might prevent its extensive use. We report a rare case of serious synovitis 3 years postoperatively in a 26-year-old man who underwent LARS artificial ligament reconstruction. During revision arthroscopy, we observed a large amount of synovial hyperplasia in the knee joint, containing a large amount of hemosiderin deposition. In addition, the femoral tunnel was placed too anteriorly, and the ligament was ruptured near the tibial tunnel. Histologically, there was thick fibrous scar tissue around the graft, and poorly organized fibrous scar tissue infiltrated into the graft fibers, which could cause loss of structural integrity of the ligament and eventual graft failure. Collectively, our findings might arouse further in-depth research on the development of artificial ligament.
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Anterior cruciate ligament reconstruction: A systematic review of polyethylene terephthalate grafts
Article
  • Nov 2011
  • ANZ J SURG
The ligament advanced reinforcement system (LARS) ligament is an artificial polyester ligament made from polyethylene terephthalate (PET) that is used for primary anterior cruciate ligament (ACL) reconstructive surgery. Recent media attention has resulted in a high awareness of this reconstructive option among patients; however, the outcomes compared with autograft are controversial. A systematic review of the literature was undertaken to examine the outcomes following LARS and long-term PET artificial grafts in ACL reconstructive surgery. The ultimate objective was to determine whether the LARS ligament should be incorporated into routine practice. A systematic search strategy from 1970 to June 2010 was used to retrieve relevant studies. Inclusion of articles was established through application of a predetermined protocol, independent assessment by two reviewers and a final consensus decision. Twelve articles met the inclusion criteria for the LARS ligament. The methodology of the identified articles was poor. Only short-term outcomes were available. These results were good with low complication rates. Eleven articles reported on other PET grafts and recorded long-term follow-up of more than 4 years. These grafts had poor outcomes and a high rate of complications. No meta-analysis was possible. There are surprisingly few studies reporting on LARS ligament outcomes. The literature has poor methodological quality. Short-term results for the LARS ligament appear good, with faster recovery times compared with autografts. Final short-term results are not significantly different from autograft. There is real concern that late failure and iatrogenic osteoarthritis may occur based on the results of other PET grafts.
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Cruciate ligament reconstruction using LARS artificial ligament under arthroscopy: 81 Cases report
Article
  • Jan 2010
There are many different materials used for ligament reconstruction. Currently, autograft, allograft, and artificial ligaments are used in the reconstruction. The objective of this study was to explore the clinical result of cruciate ligament reconstruction under arthroscopy. Eighty-one cases were reconstructed with the LARS ligament under arthroscopy, including 43 cases of anterior cruciate ligament (ACL) injury, 20 cases of posterior cruciate ligament (PCL) injury, and 18 cases of ACL combined with PCL injuries of the knee. The follow up period was 10 to 49 months. The International Knee Documentation Committee (IKDC) and Lysholm knee score scales were used for functional evaluation. We examined the anterior and posterior stability of the knee with KT-1000. According to the Lysholm knee function score scale, the average preoperative score of (44.6+/-1.4) increased to a postoperative score of (82.8+/-2.5) in the ACL group and from (46.6+/-2.3) to (80.8+/-2.0) in the PCL group. In the ACL combined with PCL injury group, the preoperative score increased from (45.2+/-1.2) to (85.5+/-2.3). According to IKDC score standards, in ACL group we evaluated 19 cases as C and 24 cases as D, preoperatively, and postoperatively 27 cases as A, 14 cases as B and two cases as C. In the preoperative PCL group, we had 11 cases defined as C and nine cases as D that resolved to 12 cases as A, seven as B and one case of C in postoperative evaluation. In the ACL combined with PCL injury group we defined four cases as C and 14 as D during preoperative scoring. These patients had postoperative grades of six cases as A, 10 as B, and two cases as C. All of the results have statistical significance. ACL, PCL, or combined ACL and PCL reconstruction using the LARS ligament under arthroscopy is a minimally invasive, safe and effective method to treat cruciate ligament injuries of the knee. Clinical results are satisfactory in the short term.
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