Keywords: Insecta, Odonata, Anisoptera, Liupanshaniidae, Libanocorduliidae, fam., gen. et sp. nov., Cenomanian, Lebanon, Limestone

A new hawker dragonfly Libanoliupanshania mimi gen. et sp. nov. is described and illustrated from the lower upper Cenomanian of Hjoula (Lebanon). Its discovery shows that the Cretaceous family Liupanshaniidae, currently recorded from South America and Eurasia, was also present in the Arabo-African Cretaceous paleocontinent. Also a new 'libelluloid' family Libanocorduliidae fam. nov. is described and illustrated on the basis of the new genus and species Libanocordulia debiei gen. et sp. nov. This taxon is characterized by a unique shape of the hindwing subdiscoidal space. Paleobiogeographic implications are discussed. The 'mid' Cretaceous marine outcrop of Hjoula is potentially a new insect konservat-Lagerstätte liable to provide crucial information on the entomofauna of the paleo-Arabo-African continent at that time.

Introduction

The fossil record of the Odonata fauna of the Cretaceous Arabo-African paleocontinent is relatively scarce. To date only four taxa are known: Libanolestes flecki Azar, Prokop et Nel, 2010, a lestomorphan zygopteran of undetermined family from the Lower Barremian Lebanese amber; Jordanhemiphlebia electronica [START_REF] Lak | Phase contrast X-ray synchrotron microtomography and the oldest damselflies in amber (Odonata: Zygoptera: Hemiphlebiidae)[END_REF][START_REF] Lak | Phase contrast X-ray synchrotron microtomography and the oldest damselflies in amber (Odonata: Zygoptera: Hemiphlebiidae)[END_REF] a hemiphlebiid zygopteran from the Lower Cretaceous Jordanian amber; Aegyptidium aburasiensis [START_REF] Schlüter | Aegyptidium aburasiensis gen. nov., spec. nov. (Aeschnidiidae) und Gondvanogomphus bartheli gen. nov., spec. nov. (Gomphidae) aus mutmasslicher Unterkreide Südwest-Ägyptens (Anisoptera)[END_REF], an aeschnidiid anisopteran and Gondvanogomphus bartheli [START_REF] Schlüter | Aegyptidium aburasiensis gen. nov., spec. nov. (Aeschnidiidae) und Gondvanogomphus bartheli gen. nov., spec. nov. (Gomphidae) aus mutmasslicher Unterkreide Südwest-Ägyptens (Anisoptera)[END_REF], a gondvanogomphid stenophlebiopteran Bechly, 1996 from the putative Lower Cretaceous of South-West-Egypt [START_REF] Schlüter | Aegyptidium aburasiensis gen. nov., spec. nov. (Aeschnidiidae) und Gondvanogomphus bartheli gen. nov., spec. nov. (Gomphidae) aus mutmasslicher Unterkreide Südwest-Ägyptens (Anisoptera)[END_REF][START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF][START_REF] Lak | Phase contrast X-ray synchrotron microtomography and the oldest damselflies in amber (Odonata: Zygoptera: Hemiphlebiidae)[END_REF][START_REF] Azar | The first damsel fly from the Early Cretaceous Lebanese amber (Odonata, Zygoptera, Lestomorpha)[END_REF]. [START_REF] Krassilov | Insect egg sets on angiosperm leaves from the Lower Cretaceous of Negev, Israel[END_REF] and [START_REF] Krassilov | Arthropod trace diversity on fossil leaves from the mid-Cretaceous of Negev, Israel[END_REF] have described some egg scar insertions on leaves from the Albian of Israel. Thus the discovery of any new fossil is of great interest as this paleocontinent was isolated during the main part of the Cretaceous [START_REF] Cao | Improving global paleogeography since the late Paleozoic using paleobiology[END_REF].

The dragonfly clade Aeshnoptera was very diverse during the Mesozoic, with taxa showing strong differences from their extant representatives. Among these curious forms, the Cretaceous family Liupanshaniidae [START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF], characterized by a very particular shape of the hindwing discoidal triangle, was widely distributed in Eurasia and South America, but hiterto unknown on the other paleocontinents (North America, Africa, Antarctica and Australia). Their apparent absence in Africa was especially surprising because the separation between South America and Africa is supposed to date back only to the very early Cretaceous [START_REF] Granot | The Cretaceous opening of the South Atlantic Ocean[END_REF]. The present discovery of a very well-preserved dragonfly belonging to this family in the Lebanese fossil fish outcrop of Hjoula (lower upper Cenomanian)

shows that the Liupanshaniidae were present in the Arabo-African Cretaceous paleocontinent. Also the discovery of new Cavilabiata (former 'Libelluloidea') belonging to a new family (Libanocorduliidae fam. nov.) in the same outcrop is of great interest because the Cavilabiata clade is known to have greatly diversified during the Late Jurassic and the early Late Cretaceous. This family shows highly specialized wing venation structures.

Outcrop, material and methods

Outcrop

The studied material originated from Hjoula (Fig. 1), Caza (Department) of Byblos, Mouhafazet (Governorate) 'Mont Lebanon', Central Lebanon, at nearly forty kilometers North-East of Beirut. The Hjoula outcrop has historically been given several ages depending on different authors. [START_REF] Botta | Observations sur le Liban et Anti-Liban[END_REF] attributed the sediments in the Haqel area to the Cretaceous. [START_REF] Lewis | The fossil fish localities of the Lebanon[END_REF] and Fraas (1878) postulated a Turonian age. Later [START_REF] Patterson | New Cretaceous berycoid fishes from the Lebanon[END_REF] and [START_REF] Hückel | Die Fischschiefer von Haquel und Hajoula in der Oberkreide des Libanon[END_REF] recognized a Cenomanian age. [START_REF] Patterson | New Cretaceous berycoid fishes from the Lebanon[END_REF] estimated a mid-Cenomanian age on the basis of the fish fauna, whereas [START_REF] Hückel | Die Fischschiefer von Haquel und Hajoula in der Oberkreide des Libanon[END_REF] placed the beds at Haqel as lower Cenomanian based on the record of the foraminiferan Orbitolina concava [START_REF] Lamarck | Liste des objets représentés dans les planches de cette livraison[END_REF] and the index ammonite Mantelliceras mantelli (Sowerby, 1814) already reported by [START_REF] Zumoffen | Géologie du Liban[END_REF].

Biostratigraphical studies of [START_REF] Dubertret | Contribution à la stratigraphie et à la paléontologie du Crétacé et du Nummulitique de la marge N.W. de la péninsule arabique[END_REF][START_REF] Dubertret | Liban, Syrie et bordure des pays voisins. Tableau stratigraphique avec carte géologique au millionième[END_REF] and [START_REF] Saint-Marc | Etude stratigraphique et micropaléontologique de l'Albien, du Cénomanien et du Turonien du Liban[END_REF] determined the sequences at Hjoula to be lower Cenomanian. [START_REF] Hemleben | Rote Tiden und die oberkretazischen Plattenkalke im Libanon[END_REF], dated them as late Cenomanian due to the assemblages of the planktonic foraminifera Praeglobotruncana stephani [START_REF] Gandolfi | Ricerche micropaleontologiche e stratigrafiche sulla Scaglia e sul Flysch cretacici[END_REF], Rotalipora cushmani [START_REF] Morrow | Foraminifera and Ostracoda from the Upper Cretaceous of Kansas[END_REF] and Rotalipora greenhornensis [START_REF] Morrow | Foraminifera and Ostracoda from the Upper Cretaceous of Kansas[END_REF]. [START_REF] Walley | The lithostratigraphy of Lebanon: a review[END_REF] assigned the outcrop to the Sannine Formation. Recently, [START_REF] Wippich | Allocrioceras from the Cenomanian (mid-Cretaceous) of the Lebanon and its bearing on the palaeobiological interpretation of heteromorphic ammonites[END_REF] confirmed a Late Cenomanian age for Hjoula based on the presence of the ammonite Allocrioceras cf. annulatum [START_REF] Shumard | Descriptions of new Cretaceous fossils from Texas[END_REF], which is a member of the lower upper Cenomanian Sciponoceras gracile Zone in the Western Interior of the USA and the Metoicoceras geslinianum Zone of the international standard. [START_REF] Fuchs | New octopods (Cephalopoda: Coleoidea) from the Late Cretaceous (Upper Cenomanian) of Hâkel and Hâdjoula, Lebanon[END_REF], confirmed a late Cenomanian age for Hjoula as well.

During the mid Cenomanian, Lebanon was mostly submerged and positioned on a shallow carbonate platform (where there were some small islands exposed) on the North-East of the Arabo-African paleocontinent at nearly 8° paleolatitude (Philip et al., 1993, Barrier and[START_REF] Barrier | Palaeotectonic maps of the Middle East: tectono-sedimentarypalinspastic maps from Late Norian to Pliocene[END_REF].

Although the deposits in the outcrop of Hjoula are clearly marine, terrestrial fossils indicate deposition close to a paleoshoreline during the early late Cenomanian, viz. terrestrial plants (pteridophytes, gymnosperms and angiosperms), invertebrates, vertebrates (complete skeletons and isolated bone of pterosaurs, turtles and fish fossils), in addition to six newly discovered complete and non-dislocate fossil dragonflies (belonging to three or four different taxa) and a fossil scarabaeoid beetle (see environmental reconstruction in Fig. 2). According to [START_REF] Krassilov | Cenomanian florule of Nammoura, Lebanon[END_REF], this mid Cenomanian floral assemblage differs markedly from both the Lower Cretaceous and the Turonian plant assemblages of the Middle East, and represents a distinct stage of the regional floristic evolution. These authors concluded that the phytogeographic affinities of the fossil fish outcrops of the mid Cenomanian of Lebanon are with contemporaneous floras of North America, Central Europe, and the Crimea; in consequence, a combination of features like xeromorphism, the prevalence of compound leaves, and the presence of deciduous angiosperms and gymnosperms may indicate climatic conditions similar in the present day Mediterranean [START_REF] Krassilov | Cenomanian florule of Nammoura, Lebanon[END_REF].

Materials and methods

The fossils were collected by the quarry workers. They were examined, measured and photographed using a Nicon SMZ 10 stereomicroscope with incident light equipped by camera lucida and an AmScope MU900 9MP digital camera. Habitus photographs were taken using a Canon EOS 60 D Camera under normal and ultraviolet lights. The raw digital images obtained on the stereomicroscope were processed with Helicon Focus stacking software, and then images were merged with Adobe Photoshop CS5.

The studied material is deposited in the Mim Museum of Mineralogy, Beirut, Lebanon.

The nomenclature of the odonatan wing venation used in this paper is based on the interpretations of [START_REF] Riek | A new interpretation of dragonfly wing venation based upon Early Carboniferous fossils from Argentina (Insecta: Odonatoidea) and basic characters states in pterygote wings[END_REF], as modified by [START_REF] Nel | Les 'Anisozygoptera' fossiles. Phylogénie et classification (Odonata)[END_REF] and [START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF]. The higher classification of fossil and extant Aeshnoptera follows [START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF].

Wing abbreviations are as follows: CuA, cubitus anterior; IR1, intercalary radial veins; MA, median anterior; MP, median posterior; N, nodus; PsA, pseudo-anal vein; Pt, pterostigma; RA, radius anterior; RP, radius posterior; Sn, subnodal crossvein. All measurements are given in mm.

Systematic paleontology

Order: Odonata Fabricius, 1793 Suborder: Anisoptera Selys in Selys and Hagen, 1954 Clade: Aeshnoptera [START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF] Family: Liupanshaniidae [START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF] Type genus. Liupanshania Hong, 1982 (China, Aptian to mid-Albian, 125.45 Holotype. F63, deposited in MIM Museum (a nearly complete fossil, with only legs, apical part of a forewing, and apical part of abdomen missing).

Age and outcrop. Early Upper Cenomanian, Hjoula, Lebanon.

Diagnosis. As for the genus (vide supra).

Description. Head poorly preserved, probably visible from below, 4.0 mm long, 6.0 mm wide.

Thorax large, but apparently narrower than head (possible deformation due to compression), ca. 11 mm long, 5.6 mm wide.

Wings hyaline ; pterostigmata sclerotized, brown. Forewing. Length 32.2 mm; width at nodus 8.8 mm; distance from base to arculus 4.0 mm; distance from base to nodus 16.4 mm; from nodus to pterostigma 8.8 mm; pterostigma rather short (length 3.6 mm; width 1.0 mm), covering four cells, and braced by a weakly oblique crossvein that is aligned with its basal side; pterostigma not in a basal position; 19 postnodal crossveins, not aligned with corresponding postsubnodal crossveins; 26 secondary antenodal crossveins between costal margin and ScP, well aligned with antenodal crossveins of second row; primary antenodal crossvein Ax1 stronger than secondary antenodals, but Ax2 not well distinct from these; Ax1 just basal of arculus; six secondary antenodals between Ax1 and Ax2; basal brace Ax0 visible; 18 antesubnodal crossveins between arculus and subnodus without any gap immediately basal of subnodus; RP and MA distinctly separated at angled arculus; three bridge-crossveins Bqs basal of subnodus; base of RP2 aligned with subnodus; nodus of normal anisopteran-type; oblique vein 'O' one cell distal of subnodus; IR2 originating 2.8 mm and RP3/4 (midfork) 3.2 mm basal of subnodus; a concave, but zigzagged Rspl, not curved, with two rows of cells between it and IR2; a strong and convex secondary longitudinal vein looking like a posterior branch of IR2 three cells basal of base of Rspl; RP2 and IR2 parallel with only a single row of cells in-between, except two rows of cells near posterior wing margin; RP2 distinctly undulated on a level with pterostigma; pseudo-IR1 very weak; RP1 and RP2 closely parallel up to pterostigma (even converging near pterostigma) with only a single row of cells in-between, but below pterostigma they become strongly divergent with two or more rows of cells in-between; RP3/4 and MA parallel and weakly undulated with a single row of cells in-between (two rows near the posterior wing margin); a concave, but strongly zigzagged Mspl with one row of cells between it and MA; postdiscoidal area distinctly widened distally (width near discoidal triangle 2.6 mm; width at posterior wing margin 5.8 mm) with three rows of cells immediately distal of discoidal triangle; hypertriangle free of crossveins (length 4.8 mm; max. width 0.5 mm); discoidal triangle nearly equilateral, large, and divided into four cells; length of anterior side 2.6 mm; of basal side 2.4 mm; of distal side MAb 3.0 mm; MAb straight, without a distinct convex secondary vein (trigonal planate) originating on it; median space free of crossveins; submedian space traversed by several crossveins plus CuP-crossing; AA divided into a strong and oblique secondary anterior branch PsA and a posterior main branch AAa, delimiting a well-defined three-celled subdiscoidal triangle, max. 2.6 mm long and basally 1.4 mm wide (= length of PsA); PsA slightly curved and ends at basal angle of discoidal triangle; a single row of cells in area between MP and CuA; MP reaching posterior wing margin on a level with nodus; CuA reaching posterior wing margin somewhat basal of level of nodus; six weak posterior branches of CuA; maximum width of cubito-anal area 1.8 mm with maximum five rows of cells between CuA and posterior wing margin; anal area ma x. 2.0 mm wide (below PsA) with two rows of large cells between AA and posterior wing margin.

Hindwing. Length 33.6 mm; width at nodus 10.6 mm; distance from base to arculus 3.6 mm; distance from base to nodus 14.0 mm; from nodus to pterostigma 11.2 mm; pterostigma elongated, covering four small cells (length 5.0 mm; max. width 1.0 mm); pterostigmal brace not oblique, aligned with basal side of pterostigma; 18 postnodal crossveins between nodus and pterostigma, not aligned with the 16 corresponding postsubnodal crossveins; 16 secondary antenodal crossveins between costal margin and ScP, not aligned with the second row of secondary antenodal crossveins between ScP and RA; primary antenodal crossveins aligned and distinctly stronger with about four or five secondary antenodal crossveins in-between; Ax1 slightly basal to arculus, and Ax2 two cells basal to distal angle of discoidal triangle; basal brace Ax0 visible; numerous antesubnodal crossveins in area between arculus and subnodus without any gap near subnodus; arculus weakly angled; bases of RP and MA shortly separated at arculus; three bridge-crossveins Bqs basal of subnodus; base of RP2 aligned with subnodus; only a single oblique vein 'O', one cell distal of subnodus; Rspl well-defined and straight with two rows of cells between it and IR2; a strong and convex secondary longitudinal vein looking like a posterior branch of IR2 three cells basal of base of Rspl; RP2 and IR2 more or less parallel with only a single row of cells in-between up to the level of pterostigma, but more distally three rows of small cells between these veins; IR2 and RP2 both strongly curved on a level with pterostigma, and RP2 even slightly undulated in this area; RP1 and RP2 are basally closely parallel (even converging near pterostigma) with only a single row of cells in-between up to pterostigmal brace vein, but more distally they become strongly divergent with two or more rows of cells in-between; pseudo-IRI weak; RP3/4 and MA parallel and only weakly undulated with a single row of cells in-between, except between their strongly curved distal parts (two rows of cells); Mspl less well-defined than Rspl, zigzagged but with a general direction straight and parallel to MAa with one row of cells between it and MA; MA and MP strongly divergent; CuAa with five well-defined posterior branches; CuAb well-defined and basally curved towards wing base; cubito-anal area max. 4.6 mm wide with up to six rows of cells between CuAa and posterior wing margin; anal area broad (max. width 5.4 mm) with up to six rows of cells between AA and posterior wing margin; anal loop posteriorly closed, well-defined; AA with two posterior branches; anal margin angular with a rather weak anal angle but a clear anal triangle, thus, it is a male specimen. Abdomen. Preserved part 31.0 mm long; eight segments preserved; male secondary genital appendages visible on second segment; a strong constriction on segment 3.

Discussion. This fossil has all the synapomorphies of the aeshnopteran family Liupanshaniidae [START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF], viz. unique shape of the very elongate and narrow hindwing discoidal triangle (anterior side of discoidal triangle distally curved and ending on the anterior side MA of hypertriangle; Mab strongly sigmoidally curved, with a very concave basal part and a strong angle in the distal part); hindwing discoidal triangle divided into several (at least three) cells by parallel crossveins; forewing discoidal triangle divided into three cells; both pairs of wings (but especially hindwing) with a strong convex secondary longitudinal vein (trigonal planate) in postdiscoidal area, originating at angle of MAb; distal accessory oblique vein between RP2 and IR2 secondarily absent.

The character 'presence of a strong, well-defined secondary vein looking like a posterior branch of IR2 basal of Rspl' is quite rare among liupanshaniids, only present in Araripeliupanshania, and absent in Guyuanaeschnidia, Liupanshania, Paramesuropetala, Paraliupanshania, Galloliupanshania, and Protoliupanshania [START_REF] Lin | Paleontological atlas of East China, Late Paleozoic[END_REF][START_REF] Hong | The Mesozoic stratigraphy and paleontology of the Guyang coal-bearing basin, Neimenggol Autonomous Region, China[END_REF][START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF][START_REF] Lin | Phylogenetic analysis of the Mesozoic dragonfly family Liupanshaniidae (Insecta: Aeshnoptera: Odonata)[END_REF][START_REF] Huang | Protoliupanshania wangi, a new genus and species from the Chinese Early Cretaceous (Odonata: Aeshnoptera: Liupanshaniidae)[END_REF]Nel et al., 2015). Other differences from these genera are as follows: Paramesuropetala has a posteriorly opened anal loop and no supplementary crossvein in submedian area [START_REF] Bechly | Chapter 11.5 Odonata: damselflies and dragonflies[END_REF]; Guyuanaeschnidia has a weaker Rspl; Protoliupanshania and Galloliupanshania have a less distinctly curved and angled hindwing MAb; Paraliupanshania has a clearly more distinct Rspl with many more rows of cells between it and IR2, many more postnodal crossveins, a posteriorly opened anal loop, and a longer pterostigma; Liupanshania has a weaker Rspl, two rows of cells between trigonal planate and MAa close to discoidal triangle, and a longer pterostigma.

Differences between Libanoliupanshania gen. nov. and Araripeliupanshania annesusae [START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF] are as follows: anterior margin of hindwing discoidal triangle ending at distal angle of triangle and not on MA; presence of a supplementary posterior branch of AA between anal triangle and anal loop in hindwing; forewing postdiscoidal areas much broader; presence of four crossveins (incl. CuP) in forewing submedian area. This last character is the main difference with this genus.Unfortunately, the submedian area is only known in Araripeliupanshania and Paramesuropetala. Generally in extant Aeshnoptera, if there are numerous crossveins in the forewing submedian space, the situation is the same in the hindwing.

Thus the special situation in Libanoliupanshania is also quite rare.

This new Lebanese fossil can be considered as a new genus and species, probably sister group of Araripeliupanshania for the shared special vein that 'forks' from IR2.

The present discovery confirms that the Liupanshaniidae were present on the 'Eurasian' (including Europe), 'South American', and also 'African' Cretaceous paleocontinents. This family remains unknown in Antarctic, Australian, and North American paleocontinents.

Together with the Rudiaeschnidae [START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF], Gomphaeschnidae Tillyard and Fraser, 1940, Burmaeshnidae Huang et al., 2017and Enigmaeshnidae Nel et al., 2008[START_REF] Bechly | A revision and phylogenetic study of Mesozoic Aeshnoptera, with description of several new families, genera and species (Insecta: Odonata: Anisoptera)[END_REF][START_REF] Nel | A new dragonfly family in the Upper Cretaceous of France (Insecta: Odonata: Aeshnoptera)[END_REF]Huang et al., 2017a,b), it is one of the aeshnopteran families that diversified between the Earliest Cretaceous and the Turonian. Among them, only the Gomphaeschnidae continued into the Cenozoic, while the oldest fossil record of the extant Aeshnidae is Cenozoic. These Odonata were probably affected by the mid-Cretaceous lacustrine revolution between the Albian and the Turonian [START_REF] Buatois | The trace-fossil record of major evolutionary events[END_REF]). It appears that the changes in the odonatan faunas were very progressive as many 'ancient' clades survived until the Turonian (Nel et al., 2015).

Clade: Cavilabiata [START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF] Family: Libanocorduliidae fam. nov.

Type genus: Libanocordulia gen. nov.

Diagnosis. All discoidal cells transverse; hindwing subdiscoidal space broad, two-celled; vein PsA very long and strong; no Rspl; no Mspl; anal loop posteriorly closed but small, only twocelled. Holotype. F64 (A and B) (part and counterpart) (Fig. 6), paratype specimen number F65 (Fig. 7A); deposited at MIM Museum of Mineralogy, Beirut Lebanon. There is one more specimen (Fig. 7B) in a private collection in Japan.

Genus

Etymology. Named after Mr. Yves Bernard Debie.

Age and outcrop. Early Upper Cenomanian, Hjoula, Lebanon.

Diagnosis. A dark band just distal of nodus in all wings.

Description. Bodies poorly preserved. Wings hyaline except for a dark band just distal of nodus ; pterostigmata sclerotized, brown.

Holotype. Forewing: length ca. 24.8 mm; width at nodus 6.5 mm; distance from base to arculus 4 mm; distance from base to nodus 13.2 mm; from nodus to pterostigma 7.0 mm; pterostigma long (length 2.5 mm; width 0.6 mm), covering three cells, and braced by a rather weakly oblique brace that is aligned with its basal side; pterostigma not parallel sided (distal side more oblique than basal side), pterostigma not in basal position; ca. five visible postnodal crossveins, with corresponding postsubnodal crossveins not preserved; 4-5 secondary antenodal crossveins between costal margin and ScP present distal of Ax2, antenodal crossveins of second row apparently aligned with those of first row; primary antenodal crossvein Ax1 not visible, Ax2 opposite basal side of discoidal triangle; antesubnodal crossveins between arculus and subnodus not visible; RP and MA distinctly separated at arculus; 2-3 bridge-crossveins Bqs basal of subnodus; base of RP2 aligned with subnodus; nodus of normal anisopteran-type; an oblique vein 'O' more than three cells distal of subnodus; IR2 originating 1.8 mm and RP3/4 (midfork) 2.5 mm basal of subnodus; no distinct Rspl; RP2 and IR2 parallel with only a single row of cells in-between, except two rows of cells near posterior wing margin; pseudo-IR1 very weak; RP1 and RP2 closely parallel up to pterostigma with apparently only a single row of cells inbetween; RP3/4 and MA parallel and weakly curved with a single row of cells in-between (two rows near posterior wing margin); no distinct Mspl; postdiscoidal area not greatly widened distally (width near discoidal triangle mm) with two rows of cells immediately distal of discoidal triangle; hypertriangle free of crossveins (length 2.6 mm; max. width 0.4 mm); free discoidal triangle transverse, quadrangular, large; length of anterior side 1.4 mm; of basal side 1.9 mm; of distal side MAb ca. 2.8 mm; MAb angular, without any trigonal planate originating on it; median space free of crossveins; submedian space traversed by CuP-crossing; AA divided into a strong and oblique secondary anterior branch PsA and a posterior main branch AAa, delimiting a well-defined subdiscoidal triangle, max. 1.5 mm long and basally 1.8 mm wide (= length of PsA); a single row of cells in area between MP and CuA; MP reaching posterior wing margin distal nodus level; CuA reaching posterior wing margin somewhat basal of level of nodus; only one weak posterior branch of CuA; maximum width of cubito-anal area 1.3 mm with two rows of cells between CuA and posterior wing margin; anal area ma x. 1.5 mm wide (below PsA) with two rows of cells between AA and posterior wing margin.

Hindwing: length ca. 22.0 mm; width at nodus ca. 9.0 mm; distance from base to arculus 4.4 mm; distance from base to nodus 9.7 mm; from nodus to pterostigma 7.1 mm; only basal half of pterostigma preserved; ca. 5-6 postnodal crossveins between nodus and pterostigma; three secondary antenodal crossveins between costal margin and ScP distal of Ax2, aligned with second row of secondary antenodal crossveins between ScP and RA; primary antenodal crossveins aligned and distinctly stronger with one secondary antenodal crossvein in-between; Ax1 just basal to arculus, Ax2 just distal to basal angle of discoidal triangle; basal brace Ax0 visible; ca. six antesubnodal crossveins in area between arculus and subnodus with a gap near subnodus; arculus straight; bases of RP and MA separated at arculus; two bridge-crossveins Bqs basal of subnodus; base of RP2 just distal to subnodus; oblique vein 'O' two cells distal of subnodus; Rspl not preserved if present; distal parts of RP2 and IR2 not preserved, but only one row of cells between them in basal half; RP3/4 and MA parallel and only weakly undulated with a single row of cells in-between; Mspl apparently absent; MA and MP strongly divergent; postdiscoidal area distally widened, two rows of cells in basal part of postdiscoidal area, but with ca. four cells along posterior wing margin; no trigonal planate; hypertriangle twice as long as discoidal triangle, free of crossveins; free discoidal triangle triangular transverse; length of anterior side 1.8 mm; of basal side 1.8 mm; of distal side (MAb) 2.8 mm; median space free of crossveins; submedian space apparently crossed by CuP-crossing; PsA strongly developed; a long two-celled subdiscoidal triangle; MP and CuA running parallel with a single row of cells in-between, but not preserved near posterior wing margin; MP and CuA probably reaching posterior wing margin on a level with nodus; MP and CuA emerging at the same point from discoidal triangle; basal part of CuA mm long, CuAb postero-basally directed; CuAa with two well-defined posterior branches; cubito-anal area max. 3.0 mm wide with at least five rows of cells between CuAa and posterior wing margin; anal area broad (maximum width 3.0 mm) with up to six rows of cells between AA and posterior wing margin; anal loop two-celled, posteriorly closed, well-defined; AA with three posterior branches; anal margin poorly preserved.

The two other specimens are attributable to the same species because of their similar sizes and identical structure of comparable preserved parts. The specimen stored in a Japanese private collection better shows the hindwing discoidal area and the head than in the two other specimens. The eyes are apparently well separated.

Discussion. The distal part of antesubnodal area free of crossveins ('cordulegastrid gap') and the gaff (= basal CuA before its branching) of hindwing at least slightly prolonged are synapomorphies of the Cavilabiata [START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF]. The absence of the basal furcation of IR2 basal of the lestine oblique vein excludes affinities with the Cordulegastrida Bechly, 1996. The pterostigmata not parallel sided, the hindwing CuAa shortened with only two branches and the large anal loop are synapomorphies of the Cristotobiata Bechly, 2003. The terminal posterior branch of CuAa secondarily branched on CuAa, the long gaff, the pterostigmata covering only two cells, and the RP3/4 and MA strictly parallel up to hind margin of wing, are synapomorphies of the Brachystigmata Bechly, 1996. The forewing discoidal triangle distinctly transverse and the two-celled elongate hindwing subdiscoidal space exclude affinities with the Nannogomphidae [START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF]and with the Hemeroscopidae Pritykina, 1977[START_REF] Pritykina | New dragonflies from Lower Cretaceous deposits of Transbaïkalia and Mongolia.] In: Fauna, flora i biostratigrafiya mezozoya i kaynozoya Mongolii [Fauna, Flora, and Biostratigraphy of the Mesozoic and Cenozoic of Mongolia[END_REF][START_REF] Bechly | Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata[END_REF][START_REF] Bechly | Description of a new species of Nannogomphus (Insecta: Odonata: Nannogomphidae) from the Upper Jurassic Solnhofen Limestone in Germany[END_REF]. The arculus not distinctly angled but more or less straight, the posterior part (crossvein) of arculus distinctly shorter than anterior part, and the hindwing MP distinctly curved towards hind margin and thus somewhat shortened, ending basal of the level of the nodus, are synapomorphies of the Neobrachystigmata Bechly, 2003. The hindwing discoidal triangle transverse, and the hypertriangles distinctly longer than triangles support affinities with the Chlorogomphida Bechly, 1996; while the anterior margin of hypertriangle nearly straight, especially in the hindwings would exclude affinities with the Paneurypalpidomorpha [START_REF] Bechly | Description of a new species of Nannogomphus (Insecta: Odonata: Nannogomphidae) from the Upper Jurassic Solnhofen Limestone in Germany[END_REF]. Affinities with the Juracorduliidae Bechly, 2003 are excluded because of the smaller anal loop [START_REF] Bechly | Juracordulia schiemenzi gen. et sp. nov., eine neue Libelle aus den Solnhofener Plattenkalken (Insecta: Odonata; Anisoptera)[END_REF]. Nevertheless, the forewing discoidal triangle of Libanocordulia more or less transverse instead of being elongate, plus the lestine oblique veins two cells distal of the subnodus do not correspond to the situation in the Chlorogomphida. Also the two-celled anal loop strongly differs from those of the other representatives of this group that have distinctly broader anal loops [START_REF] Bechly | The first fossil record and first New World record for the dragonfly clade Chlorogomphida (Insecta: Odonata: Anisoptera: Araripechlorogomphidae n. fam.) from the Crato Limestone (Lower Cretaceous, Brazil)[END_REF]. Thus the exact position of Libanocordulia remains uncertain. The very strong and long PsA and large subdiscoidal cell are unique characters among the whole Cavilabiata, supporting an attribution to a new family.

Conclusion

The family Liupanshaniidae was quite widely distributed in Eurasia, South America and now Africa during the Early Cretaceous, suggesting a wider distribution on all continents, a Late Jurassic origin, and an extinction during the Late Cretaceous (Nel et al., 2015). On the contrary, the Libanocorduliidae is currently restricted to the Cretaceous Arabo-African continent as is the Gondvanogomphidae, suggesting an episode of Arabo-African diversification of the Odonata during the Early Cretaceous, after the separation of this continental mass from the rest of Gondwana. It is also supporting a 'bush' diversification of the whole clade Cavilabiata at this period [START_REF] Fleck | The oldest record of the Libellulidae from the Upper Cretaceous of Kazakhstan (Odonata, Anisoptera)[END_REF][START_REF] Nel | A new family of 'libelluloid' dragonfly from the Middle Jurassic Daohugou in northeastern of China (Odonata: Anisoptera: Cavilabiata)[END_REF]. The Cenozoic 'survivors' of this diversification are the extant Libellulidae and related families [START_REF] Zeiri | A new libelluloid family from the Eocene Green River Formation (Colorado, USA) (Odonata, Anisoptera)[END_REF]. It is rather unusual to find only large insects in a marine outcrop [START_REF] Beaury | The first fossil insect from the deep-water marine Early Miocene of Zillerleite, Germany (Diptera: Bibionidae)[END_REF][START_REF] Ataabadi | A locust witness of a transoceanic Oligocene migration between Arabia and Iran (Orthoptera: Acrididae)[END_REF]. These rather large dragonflies were collected by quarry workers who are used to search after large fossils (fishes, etc.). Thus it is possible that a collection bias occurred. Nevertheless, the same phenomenon occurs in the historical marine Bavarian Late Jurassic outcrops in which dragonflies are much more frequent than other insects. Thus a taphonomic bias cannot be excluded too in favor to the preservation of the strong flyers. More generally, the presence of several dragonflies in the Cenomanian marine layers of Hjoula suggests that it is potentially a konservat-Lagerstätte, important for future studies of the 'mid' Cretaceous Arabo-African entomofauna that is currently nearly unknown. [START_REF] Dubertret | Carte géologique de la Syrie et du Liban. Délégation générale de France au Levant[END_REF] and Quartaba [START_REF] Dubertret | Carte géologique de la Syrie et du Liban. Délégation générale de France au Levant[END_REF]

Etymology.

  Named after combination of Libano = Lebanon in Latin and Liupanshania. Libanoliupanshania mimi sp. nov. (Figs. 3-5) Etymology. Named after MIM Museum where the material is deposited.

  postdiscoidal area therefore distally widened, two rows of cells in basal part of postdiscoidal area, but with about 24 small cells along posterior wing margin; four convex secondary longitudinal veins (intercalaries) in distal part of postdiscoidal area; very strong convex secondary longitudinal vein (trigonal planate), originating at strongly pronounced angle of distal side MAb of discoidal triangle and distally becoming more indistinct and zigzagged, finally ending on MP; one row of cells between trigonal planate and MA, and one row of cells between it and MP; hypertriangle free of crossveins; discoidal triangle very long, narrow, and divided into four cells by parallel crossveins; length of anterior side 3.6 mm; of basal side 0.8 mm; of distal side, 3.2 mm; anterior side of discoidal triangle apically curved and ending at distal angle of discoidal triangle; MAb with a very peculiar structure, viz its basal part very concave, its distal angle very pronounced, and part distal of angle straight; median space free of crossveins; submedian space only traversed by CuP-crossing; PsA reduced to an oblique weak cubito-anal crossvein ending on basal side of discoidal triangle; subdiscoidal triangle indistinct, very small and unicellular. MP and CuA running parallel with a single row of cells in-between, except near posterior wing margin (two rows of cells); MP and CuA reaching posterior wing margin on a level with nodus; subdiscoidal veinlet reduced, and gaff very short;

  Libanocordulia gen. nov. Type species: Libanocordulia debiei sp. nov. Etymology. Named after a combination of Libano = Lebanon in Latin and Cordulia. Diagnosis. Hindwing MP strongly zigzagged, appearing as a secondary vein between MAa and CuAa.Libanocordulia debiei sp. nov.

Figures

  Figures

Fig. 1 .

 1 Fig. 1. Outcrop of Hjoula, Caza (Department of Byblos), Mouhafazet (Governorate) 'Mont

  1/50000. C2a = Jezzinian, oolitic yellow limestone; C2b = Jezzinian, white mudstone limestone; C3 = Albian; C4 = Cenomanian; Thickened lines indicate faults. B. General view.

Fig. 2 .

 2 Fig. 2. Reconstruction of the palaeoenvironment of Hjoula during the early late Cenomanian.

Fig. 3 .

 3 Fig. 3. Libanoliupanshania mimi gen. et sp. nov., holotype F63. A. Photograph of general

Fig. 4 .

 4 Fig. 4. Libanoliupanshania mimi gen. et sp. nov., holotype F63. Detail of wings. Scale bar: 10

Fig. 5 .

 5 Fig. 5. Libanoliupanshania mimi gen. et sp. nov., holotype F63. Reconstruction of fore-and

Fig. 6 .

 6 Fig. 6. Libanocordulia debiei gen. et sp. nov., holotype F64. Photographs of general habitus.

Fig. 7 .

 7 Fig. 7. Libanocordulia debiei gen. et sp. nov. Photographs of general habitus. A. Paratype F65.

Fig. 8 .

 8 Fig. 8. Libanocordulia debiei gen. et sp. nov. Forewings. A. Right, holotype F64 A. B. Left,

Fig. 9 .

 9 Fig. 9. Libanocordulia debiei gen. et sp. nov. Hindwings. A. Right, holotype F64 A. B. Left,

Acknowledgements

We sincerely thank Rob Coram and an anonymous referee for their very useful and instructive comments on the first version of the paper. DA wants to thank as well Mr F. Escuillié for his major contribution in acquiring and donating the studied material. Financial support was provided by the Strategic Priority Research Program (B) (XDB18000000) and the National Natural Science Foundation of China (41688103). DA wants to thank the Chinese Academy of Sciences for the financial support under the CAS President's International Fellowship Initiative (PIFI). This paper is a contribution to the research project 'Characterization and sedimentological, paleontological and geochemical studies of the Lower Cretaceous dysodiles of Lebanon' financed by the Lebanese University to DA; and to the activity of the laboratory 'Advanced Micropaleontology, Biodiversity and Evolution Researches (AMBER)' at the Lebanese University.


Diego Da Hora

Dario Rossi

Vassilis Christophides

Renata Teixeira

A practical method for measuring Web above-the-fold time

Page load time (PLT) is still the most common application Quality of Service (QoS) metric to estimate the Quality of Experience (QoE) of Web users. Yet, recent literature abounds with interesting proposals for alternative metrics (e.g., Above The Fold, SpeedIndex and variants) that aim at closely capturing how users perceive the Webpage rendering process. However, these novel metrics are typically computationally expensive, as they require to monitor and post-process videos of the rendering process, and have failed to be widely deployed.

In this demo, we show our implementation of an opensource Chrome extension that implements a practical and lightweight method to measure the approximated Above-the-Fold (AATF) time, as well as others Web performance metrics. The idea is, instead of accurately monitoring the rendering output, to track the download time of the last visible object on screen (i.e., "above the fold"). Our plugin also has options to save detailed reports for later analysis, a functionality ideally suited for researchers wanting to gather data from Web experiments.

INTRODUCTION

The Web is still a dominant applications in today's Internet, that evolved from delivering simple static contents to serve dynamic and complex content. Measuring the impact of different session protocols (e.g., HTTP/2 and QUIC), network technologies (e.g., landline vs 5G) and Web browser configurations (e.g., V8 vs Gecko) on Web browsing quality of experience (QoE) is essential to enhance user satisfaction.

Yet, defining Web QoE is hard since the Web browsing process is complex with the request, download, and rendering of hundreds of objects from tens of domains making up a single Webpage. The literature introduces several objective QoS metrics, which we exemplify with the help of Fig. 1. The time to load a Web page has a number of components, such as the time at which the first byte is received (TTFB), the time at which the first object is painted (TTFP) by the browser, the parsing of the Document Object Model (DOM), to the complete page (PLT) -the latter one typically measured using the onload event, and that is commonly used nowadays in both academia and industry. We notice that whereas network-related time-instant metrics (e.g. TTFB, DOM, PLT) are easy to measure, renderingrelated metrics (e.g. TTFP, VisualComplete) are harder to define across browsers [5]. An interesting metric proposed by Google in this class is represented by the Above-the-Fold (ATF) time [START_REF] Brutlag | Above the fold time: Measuring Web page performance visually[END_REF], defined as the time at which the content shown in the visible part of the Webpage is completely rendered. Albeit interesting, the ATF metric is neither available in Webpagetest (https://www.webpagetest.org/) nor defined in W3C's navigation timing specifications (https: //www.w3.org/TR/navigation-timing/). This omission is possibly because the ATF time is significantly more complex to measure.

At the same time, the interest for metrics such as ATF is clear considering the example "waterfall" diagram in Fig. 1, where different objects of the page are depicted as a Gantt chart: it can be seen that while the above-the-fold portion of the page is fully rendered in about 2 seconds (a timescale likely appreciated by users), the page download process continues for a (significantly) longer time, with the onload event signaled at 8.5 seconds (a timescale at which users would likely be impatient). Our practical proposal to measure the ATF time is then interesting to gather, at a low computational cost, more telling and relevant Web QoE metric than PLT.

DEMO HIGHLIGHTS

In this demo, we showcase our practical method to approximate the Above-the-Fold time (AATF). In particular, we developed a Chrome extension that implements AATF and calculate other Web performance metrics, that we make available as open source software [START_REF]Approximate ATF Chrome extension[END_REF]. A preview of the demo is available at https://newnet.telecom-paristech.fr/index.php/webqoe/. Methodology. We approximate the Approximated Abovethe-Fold (AATF) time from the browser itself without requiring image processing. We leverage the browser's ability to determine the position of objects inside a fully rendered page and the recorded loading times of HTTP requests. First, we detect all the elements of the Webpage and the browser window size. Then, we trace loading time and resource type for all HTTP requests, and determine which objects are rendered above-the-fold. To do so, we use simple heuristics to classify resource types between images, JavaScripts (JS), CSS, HTML, etc. For objects that are directly rendered (e.g., of the image class), the coordinates make it obvious whether they are, at least partly, above-the-fold.

Implementation. We implemented the method to compute the AATF time as an open-source Chrome extension[1].

To avoid affecting the browsing experience by design, the script is executed after the onLoad event triggers. We use JavaScript to detect visible DOM objects: for each object, we detect its position and size on the page. We use this information alongside the browser windows' to determine which DOM objects are visible and above-the-fold. We use the Window.performance API to obtain the name, type, and timing information about the resources loaded in the page. We compare the src field of DOM object to the url of HTTP requests to match HTML objects to its corresponding timing information. Finally, we calculate the AATF as early described.

Functionalities. Our Chrome extension not only reports the AATF, but also other relevant metrics whose details are given in [START_REF] Neves Da Hora | Narrowing the gap between QoS metrics andWeb QoE using Above-the-fold metrics[END_REF]. In particular, the plugin computes three time instant-metrics (namely DOM, PLT, and AATF), as well as three time-integrals metrics (namely ObjectIndex, ByteIndex, and ImageIndex). We also calculate integral metrics with an "early cut-off" at AATF, for a total of 9 WebQoE metrics.

The plugin is suitable for both interactive use (e.g., in classrooms) as well as to automate measurement campaigns (e.g., for research). For its interactive use, the plugin can be configured to display statistics at different verbosity levels. The plugin has options for saving a detailed log with both performance metrics and a detailed description of the page content (useful for later analysis). It can be configured to execute either a set amount of time after PLT or after a fixed time after page load start, whichever comes first -this makes automated test robust, since the PLT event may not be signaled in some circumstances.

Demonstration workflow. We will do a live demonstration of the plugin capabilities measuring all WebQoE metrics in two network scenarios: good network conditions and limited bandwidth. The objective is for users to perceive the difference in web QoE metrics in both scenarios, judging by themselves which metrics (among DOM, AATF, and PLT) are more representative of their subjective experience. We will emulate both scenarios using Google chrome's network throttling tool. An illustration of these metrics is shown in Fig. 2, when browsing the Amazon webpage. We observe that only 8 of the 154 images are located above-the-fold (circled in blue in Fig 2 ), with a significant difference between PLT, AATF, and derived metrics. The plugin clearly shows that while the full Amazon page is rendered in about 5 seconds (AATF), the page completes in over 16 seconds (PLT).

We will also show, for the interested user, the results of a thorough and systematic comparison of these metrics with a measurement campaign involving several thousands Mean Opinion Scores (MOS) points from real users [START_REF] Neves Da Hora | Narrowing the gap between QoS metrics andWeb QoE using Above-the-fold metrics[END_REF] -presented at PAM 2018.

Figure 1 :

 1 Figure 1: Loading process of an example page, annotated with Web performance metrics.

Figure 2 :

 2 Figure 2: Example of AATF plugin in action: all objects above the fold are rendered on or before ATF=5.37s but the page only finishes loading at PLT=16.11sec.

ACKNOWLEDGEMENTS

This work was carried out at LINCS (http://www.lincs.fr) and benefited from the support of NewNet@Paris, CiscoâĂŹs Chair "Networks for the Future" at Telecom ParisTech (http: //newnet.telecom-paristech.fr).

DEMO REQUIREMENTS

This demo has very light requirements. We describe bellow the equipment, time and space necessary for carrying out our demonstration.

Equipment. We will use one laptop, which requires internet connection, and one monitor. We will also display a poster detailing the motivation and theory behind our work.

Space. The default space of one table space and poster board is enough for our equipment and poster.

Setup-time. We expect a setup-time of approximately 30 minutes.

Additional requirements. While internet access is important (i.e. a part of the demo), the default is enough. We can fallback to a locally hosted version of the demo in case of internet failure.


Yoann Blache
email: yoann.blache@univ-lyon1.fr

PhD Raphaël Dumas

PhD Jacques 3 De Guise

Adnan Saithna

Bertrand Sonnery-Cottet

Mathieu Thaunat

Technical considerations in lateral extra-articular reconstruction coupled with anterior cruciate ligament reconstruction: A simulation study evaluating the influence of surgical parameters on control of knee stability

Keywords: simulated pivot-shift, femoral attachment site, tibial attachment site, knee flexion at surgery, graft tension at surgery, anterior-cruciate ligament

Technical considerations in lateral extra-articular reconstruction coupled with anterior cruciate ligament

reconstruction: A simulation study evaluating the influence of surgical parameters on control of knee stability

Introduction

Anterior-cruciate ligament (ACL) ruptures are one of the most common knee injuries in individuals participating in sports activities. Most injured athletes will undergo ACL reconstruction, but there is an important risk of re-rupture [START_REF] Paterno | Incidence of Second ACL Injuries 2 Years After Primary ACL Reconstruction and Return to Sport[END_REF][START_REF] Salmon | Incidence and risk factors for graft rupture and contralateral rupture after anterior cruciate ligament reconstruction[END_REF] and only 65% of patients are able to return to their pre-injury level of sport [START_REF] Ardern | Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and metaanalysis including aspects of physical functioning and contextual factors[END_REF]. In order to decrease the risk of a re-rupture, lateral extra-articular reconstruction (LER) is being performed with increasing frequency [START_REF] Cerciello | Extra-Articular Tenodesis in Combination with Anterior Cruciate Ligament Reconstruction: An Overview[END_REF][START_REF] Slette | Biomechanical Results of Lateral Extra-articular Tenodesis Procedures of the Knee: A Systematic Review[END_REF], since such a reconstruction is believed to improve the control of knee stability with respect to internal rotation and anterior translation (Inderhaug et al., 2017a, b;[START_REF] Katakura | Effects of different femoral tunnel positions on tension changes in anterolateral ligament reconstruction[END_REF][START_REF] Noyes | Is an Anterolateral Ligament Reconstruction Required in ACL-Reconstructed Knees With Associated Injury to the Anterolateral Structures[END_REF][START_REF] Sonnery-Cottet | Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament -deficient knee[END_REF][START_REF] Sonnery-Cottet | Outcome of a Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction Technique With a Minimum 2-Year Follow-up[END_REF].

The optimum surgical technique used to perform LER is not clearly defined and is a topic of great debate [START_REF] Slette | Biomechanical Results of Lateral Extra-articular Tenodesis Procedures of the Knee: A Systematic Review[END_REF]. Many variations in surgical settings differentiate the common LER procedures and therefore, their likely influence on the control of knee rotation and translation. However, four surgery settings are often put forward in the literature as being of potential importance [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF]Inderhaug et al., 2017a, b;[START_REF] Katakura | Effects of different femoral tunnel positions on tension changes in anterolateral ligament reconstruction[END_REF]: the femoral and tibial attachment sites, graft tension, and the knee flexion angle at the time of graft fixation.

LER tension during knee internal rotation and flexion, has been shown to be sensitive to the femoral attachment site [START_REF] Katakura | Effects of different femoral tunnel positions on tension changes in anterolateral ligament reconstruction[END_REF]. A more favorable behavior was observed when the graft was fixed proximally to the lateral femoral epicondyle in comparison to a graft located distally to the lateral femoral epicondyle [START_REF] Imbert | Isometric Characteristics of the Anterolateral Ligament of the Knee: A Cadaveric Navigation Study[END_REF][START_REF] Katakura | Effects of different femoral tunnel positions on tension changes in anterolateral ligament reconstruction[END_REF]. Knee flexion angle at the time of graft fixation has also been reported to potentially influence the ability of a LER to control knee stability. Inderhaug et al. (2017a) observed that knee rotation and translation were restored after LER with an anterolateral ligament (ALL) procedure [START_REF] Sonnery-Cottet | Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction[END_REF], only when the graft was fixed in full knee extension. By contrast,

A C C E P T E D M A N U S C R I P T

the control of knee rotation and translation after LER with a modified Lemaire procedure was not influenced (Inderhaug et al., 2017a) or was only moderately [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF] sensitive to the knee flexion angle at the time of fixation. Finally, the influence of graft tension at the time of fixation on the control of knee stability is controversial. Inderhaug et al. (2017b) highlighted that the sensitivity of the control of knee rotation and translation to the graft tension at the time of fixation was dependent on the type of LER procedure (i.e. McIntosh, deep or superficial Lemaire or ALL) whereas [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF] observed no difference in knee kinematics after an ALL procedure performed with graft tension at 20 and 40N.

Although previous studies have yielded important information about the sensitivity of control of knee stability after LER to some surgery settings, some limitations remain. Firstly, most of the studies assessing the effect of one surgery setting have compared several LER procedures.

Consequently, the influence of the tested surgery setting may be subject to confounding factors such as differences in the characteristics of grafts used for different techniques (e.g. Iliotibial band vs. Gracilis tendon), the number of strands (single vs. double strand) or the path of the lateral tenodesis (superficial vs. deep to the lateral collateral ligament). Secondly, the sensitivity to one surgery setting has typically been assessed either alone or coupled to a single additional surgery setting. However, none of the previous studies have assessed the more likely clinical scenario of possible interactions between all four of the surgery settings described above.

Although this is something that could be evaluated in a cadaveric study, the advantage of computer simulation is that it is possible to perform a very large number of virtual surgeries to comprehensively evaluate the nature of these interactions while bypassing the cost, time constraints and inter-specimen variation posed by a cadaveric approach.

The purpose of this study was therefore to determine how sensitive is the control of knee rotation and translation, during a simulated pivot-shift scenarios, to four surgery settings: the femoral and tibial attachment sites, and the knee flexion angle and graft tension at the time of

A C C E P T E D M A N U S C R I P T 5
graft fixation. To that end, a computer model was used to simulate all surgeries procedures regarding the four settings, and then to calculate LER forces and moments during simulated pivot shift scenarios. Regarding the literature, it was hypothesized that the control of knee rotation and translation was sensitive to the femoral and tibial attachment site as well as the knee flexion angle at the time of graft fixation, while graft tension at the time of fixation should minimally influence the control of knee rotation and translation during the simulated pivot-shift scenarios.

Methods

Computer model

An adapted Opensim computer model was implemented (Opensim 3.3, Delp et al. ( 2007))

(Figure 1). The bony geometry of the modelled knee was extracted from a CT-scan (slice of 0.6 mm, Siemens Somaton, Erlangen, Germany) of a single healthy male participant (Age: 35 years, Height: 1.75 m, Mass: 80 Kg). The participant declared no history of lower limb injury and gave informed consent to study participation, which was previously approved by the Institutional Review Board of "Hôpital Privé Jean Mermoz" (# 2017-02). The model included also a spherical wrapping object surrounding the lateral epicondyle in order to make the ligament path follow the bone geometry (Figure 1).

In addition, EOS® bi-planar images (EOS Imaging Inc., Paris, France) of the participant were used to obtain the physiological weight bearing knee kinematics during quasi-static squats at 0, 10, 20, 30 and 60° of knee flexion (one trial per knee pose) [START_REF] Clement | Soft tissue artifact compensation in knee kinematics by multi-body optimization: Performance of subject-specific knee joint models[END_REF]. Then, a cubic spline interpolation was performed (Matlab R2017b, The MathWorks Inc., Natick, MA) to introduce in the computer model the couplings between the physiological knee flexion angle (from 0 to 60°) and the five other degrees of freedom, namely, internal-external rotation,

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abduction-adduction, superior-inferior translation, anterior-posterior translation and mediallateral translation [START_REF] Wu | ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion--part I: ankle, hip, and spine[END_REF] (Figure 1 and supplementary_file_1.docx).

Simulated lateral extra-articular reconstruction

In order to assess the sensitivity of LER behavior to the four surgery settings, a total of 625 surgeries were simulated based upon five different variations of each of the following parameters: femoral attachment site, tibial attachment site, knee flexion angle at the time of fixation, and graft tension at the time of fixation. Each simulated surgery was performed using a single-strand gracilis graft with a stiffness of 65 N.mm [START_REF] Wytrykowski | Cadaveric Study Comparing the Biomechanical Properties of Grafts Used for Knee Anterolateral Ligament Reconstruction[END_REF].

Femoral attachment sites-five femoral attachment sites were tested with regards to the isometric behavior of the lateral tenodesis described in the literature [START_REF] Kittl | Length change patterns in the lateral extra-articular structures of the knee and related reconstructions[END_REF][START_REF] Krackow | Optimization of knee ligament position for lateral extraarticular reconstruction[END_REF][START_REF] Sonnery-Cottet | Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament -deficient knee[END_REF][START_REF] Van De Velde | In Vivo Length Changes of the Anterolateral Ligament and Related Extra-articular Reconstructions[END_REF][START_REF] Wieser | Assessment of the Isometry of the Anterolateral Ligament in a 3-Dimensional Weight-Bearing Computed Tomography Simulation[END_REF].

They were located on a half-circle of 1cm diameter posterior to the lateral epicondyle (Figure 2).

Tibial attachment sites-five tibial attachment sites were tested and were located on a line from Gerdy's tubercle to the projection of the tip of the fibula head [START_REF] Wieser | Assessment of the Isometry of the Anterolateral Ligament in a 3-Dimensional Weight-Bearing Computed Tomography Simulation[END_REF]. These five locations included previously reported tibial attachment sites used in clinical practice [START_REF] Slette | Biomechanical Results of Lateral Extra-articular Tenodesis Procedures of the Knee: A Systematic Review[END_REF][START_REF] Sonnery-Cottet | Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament -deficient knee[END_REF] (Figure 2).

Knee flexion angle at the time of graft fixation-five knee flexion angles at the time of graft fixation were tested: 0° (full extension), 15°, 30°, 45° and 60° in line with previous studies [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF]Inderhaug et al., 2017a).

Graft tension at the time of fixation-five graft tensions at the time of fixation were tested, namely 20N, 25N, 30N, 35N and 40N in line with graft tension measured on cadavers [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF]Inderhaug et al., 2017b) or by our team of surgeons during real surgery (data not published).

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LER moments and forces

In line with the range of motions observed by [START_REF] Bull | Intraoperative measurement of knee kinematics in reconstruction of the anterior cruciate ligament[END_REF], the computer model was used to place the knee in positions corresponding to pivot-shift scenarios (n=960). The latter corresponded to a knee flexion between 10 and 30° combined with increased internal rotation (from 1 to 8°) and anterior translation (from 1 to 6 mm) with respect to the weight-bearing participant kinematics measured with bi-planar images (Figure 1). For each knee position and the 625 simulated surgeries, reconstructed LER length was calculated using the computer model. Based on LER length and its stiffness [START_REF] Wytrykowski | Cadaveric Study Comparing the Biomechanical Properties of Grafts Used for Knee Anterolateral Ligament Reconstruction[END_REF] (Figure 1), the force produced by LER in the three dimensional directions was computed. Finally, three dimensional LER moments at the knee joint center were calculated as the cross product of LER force and its lever arm relative to the midpoint between medial and lateral femoral epicondyles (Figure 1).

Sensitivity analysis

The analysis was performed only for the internal-external moment and anterior-posterior force, which are responsible for knee stability. The sensitivity of the LER force and moment to each surgery setting was assessed by computing the coefficient of variation of the LER force/moment for a given surgery setting with regards to the three remaining surgery settings. For instance, the coefficient of variation of the LER moment/force due to the modification of the femoral attachment site was computed for each variable of tibial attachment site, knee flexion angle and graft tension at the time of fixation. The procedure was repeated in order to test all possible combinations of the surgery settings.

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Results

The sensitivity analysis revealed similar tendencies between the LER internal-external rotation moment and anterior-posterior force variability regardless of the surgery setting.

Graft tension at the time of fixation -The coefficient of variation of LER external rotation moment and posterior force was included between 0% and 2.4% depending on the other surgery settings. These variations corresponded on average to 0.15 N.m (SD 0.03) and 4.4 N (SD 0.9)

for the LER external rotation moment and posterior force respectively. variations equal to 4.1 N.m (SD 1.9) and 116.9 N (SD 51.9) respectively. The coefficient of variation of the LER external rotation moment and posterior force was between 26.5% and 102.2% depending on the other surgery settings. The smallest sensitivity of LER behavior to variation in knee flexion angle at the time of graft fixation was observed when the graft was fixed distal to the femoral epicondyle and posteriorly on the tibia. When simulating a Lemaire procedure, the coefficient of variation of LER moment/force with regards to knee flexion angle at the time of graft fixation was equal to 70.0%, while a coefficient of variation of 53.6% was observed for ALL procedure (Figure 5).

Discussion

This study aimed to determine how sensitive is the control of knee rotation and translation, during a simulated pivot-shift, to four surgery settings: the femoral and tibial attachment sites, and the knee flexion angle and graft tension at the time of graft fixation. The main findings of this study were that graft tension at the time of fixation barely influenced the control of knee rotation and translation when ranging between 20 and 40 N, while the femoral or tibial attachment sites and knee flexion angle at the time of fixation may drastically influence the control of knee internal rotation and anterior translation during a pivot-shift scenario. are in the range of those found in the literature for dynamic activities [START_REF] Gasparutto | Kinematics of the Normal Knee during Dynamic Activities: A Synthesis of Data from Intracortical Pins and Biplane Imaging[END_REF].

Evaluation of model outputs

In addition, similar to [START_REF] Kernkamp | In Vivo Anterolateral Ligament Length Change in the Healthy Knee During Functional Activities-A Combined Magnetic Resonance and Dual Fluoroscopic Imaging Analysis[END_REF], we denoted that LER lengthened during the early degrees of knee flexion and started to shorten at about 35 degrees of knee flexion when the femoral graft was located posteriorly and proximally to the femoral epicondyle and the tibial graft positioned on the gerdys's tubercle or anatomical insertion of the anterolateral ligament (supplementary_file_2.docx). In addition, previous cadaveric studies [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF]Inderhaug et al., 2017a, b) pointed out that LER controlled knee rotation and anterior translation. Another way to consider these outcomes is that increasing knee internal rotation and/or anterior translation would involve an increased LER external rotation moment and/or posterior force (since the ligament is a passive structure depending only on its lengthening).

Our results are in accordance with this statement since LER external rotation moments and posterior forces were the smallest when the knee was positioned without exaggerated rotation or translation (i.e., poses corresponding to the physiological weight-bearing knee flexion). In contrast, LER external rotation moments and posterior forces increased for knee positions with an exaggerated internal rotation or anterior translation.

Sensitivity analysis

The influence of graft tension at the time of fixation on the control of knee rotation and translation has been controversial. [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF] reported no difference in knee kinematics between a graft fixed at 20 or 40 N when performing an ALL procedure [START_REF] Sonnery-Cottet | Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction[END_REF] in a cadaveric study. In contrast, also for ALL reconstruction, Inderhaug et al. (2017b) observed that, a graft tension of 20 N under-constrained knee rotation and anterior translation, while at 40 N, knee kinematics were almost restored. It was also observed that for

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modified Lemaire or McIntosh procedures, knee stability was not influenced by graft tension at the time of fixation (Inderhaug et al., 2017b). Our results suggest that graft tension at the time of fixation barely influences the control of knee internal rotation and translation during a pivotshift scenario. Additional findings to previous studies [START_REF] Geeslin | Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis[END_REF]Inderhaug et al., 2017b) are that our conclusions are the same whatever the femoral, tibial attachment sites and knee flexion angle at the time of fixation. In consequence, whatever the procedure, surgeons performing LER should not focus on graft tension at the time of fixation whether the latter ranges between 20 and 40 N.

The control of knee internal rotation has been shown to be sensitive to the femoral graft attachment site when LER was fixed on the tibia at mid distance between Gerdy's tubercle and fibula head, and at 20° of knee flexion [START_REF] Katakura | Effects of different femoral tunnel positions on tension changes in anterolateral ligament reconstruction[END_REF]. For a similar configuration, we observed that, indeed the tested femoral attachment site led to variations, ranging between 10 and 30%, in the control of both knee internal rotation and anterior translation. Nevertheless, the influence of the tested femoral attachment sites on knee stability, during a pivot-shift scenario, depended also on both knee flexion angle at the time of fixation and the tibial attachment site.

The main applications were that, firstly if surgeons want to limit the influence of the femoral attachment site on the control of knee stability, the graft should be fixed in full extension or 15° of flexion. Secondly, when the tibial attachment site is between the ALL location and Gerdy's tubercle with a knee close to full extension (below 15°), the tested femoral attachment sites involved less than 15% of variation in the control of knee rotation and translation. By contrast, if surgeons choose posterior tibial attachment sites for LER, the location of the femoral attachment site would have more influence on the control of knee stability during a pivot-shift scenario.

From previous works (Inderhaug et al., 2017a;[START_REF] Wieser | Assessment of the Isometry of the Anterolateral Ligament in a 3-Dimensional Weight-Bearing Computed Tomography Simulation[END_REF], it may be hypothesized that tibial attachment site has a small influence on the control of knee stability. Indeed, Inderhaug attachment sites, and pointed out that both procedures make it possible to restore knee kinematics. However, ALL and Lemaire procedures were not performed with the same graft (2 strands Gracilis vs. Ilio Tibial Band), which may bias the hypothesis made on the influence of the tibial insertion on the control of knee stability. Our results suggest that tibial attachment site influences the control of knee rotation and translation during a pivot-shift scenario. Especially, we pointed out that when surgeons fix the graft posteriorly and proximally to the femoral epicondyle [START_REF] Sonnery-Cottet | Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament -deficient knee[END_REF], the choice of the tibial attachment site is crucial since 15 to 67% of variation was observed in the control of knee stability. In addition, the choice of the tibial attachment site was more predominant if the graft was fixed with the knee in full extension.

Knee flexion angle at the time of graft fixation may influence the control of knee rotation and translation depending on the type of LER procedure. In a cadaveric study, for the Lemaire procedure, knee flexion angle at the time of graft fixation did not influence knee kinematics, but for the ALL procedure, knee stability was restored only when the graft was fixed in full extension (Inderhaug et al., 2017a). In the present study, we also observed that the control of knee internal rotation and anterior translation during a pivot-shift scenario was influenced by knee flexion angle at the time of graft fixation depending on both the femoral and tibial attachment site. When considering the bone attachment sites used for ALL (Sonnery-Cottet et al., 2016) and [START_REF] Lemaire | Ruptures anciennes du ligament croise anterieur. Frequence-clinique traitement[END_REF] procedures, different knee flexion angles at the time of graft fixation involved variations in the control of knee rotation and translation (up to 70%). These results suggest that knee flexion angle at the time of graft fixation is an important surgery setting to take into consideration by surgeons when performing LER either for ALL or Lemaire procedure. Our results are similar to those of Inderhaug et al. (2017a) for ALL procedure, while they differ for Lemaire procedure. An explanation may be that Inderhaug et al. (2017a) applied

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external forces to the tibia and evaluated knee kinematics, while in our study, the knee was placed in a pivot-shift scenario and we measured LER forces and moments. The two conditions may involve different load on LER, which may preclude direct comparison between the two studies.

The current study displayed some limitations that warrant discussion. Firstly, only one participant took part in this study to build the numerical model used for sensitivity analysis.

However, the analysis performed in our study explores a large range of internal rotations and anterior translations (i.e. pivot-shift volume) and encompasses the kinematic variability that would have been observed in a larger cohort study. Moreover, the post-operative kinematics depending on the different surgery settings remains unknown. Nevertheless, only pivot-shift scenarios were simulated which corresponded to an exaggerated internal rotation and anterior translation. It was assumed that such post-operative exam would produce knee positions that fall within the range tested within the sensitivity analysis. Secondly, all simulated surgeries were performed with a Gracilis graft characterized by a linear stiffness of 65 N.mm, while Gracilis stiffness is patient dependent. Furthermore, for the Lemaire procedure a different graft stiffness is observed since the Ilio tibial band is used instead of the Gracilis tendon. To overcome this limitation, we have repeated the experimentation with a graft stiffness corresponding to an Ilio tibial band and we observed similar results (see supplementary_file_3.docx). Finally, contrary to finite element models, our computer model was composed of frictionless structures. Consequently, contact forces between the ligaments and the bones were not taken into consideration in the computation of knee joint moments.

Conclusions

Computer modeling made it possible to simultaneously test the influence of four surgery settings, namely, femoral and tibial attachment sites, and knee flexion angle and graft tension

Femoral

  attachment site -Changing femoral attachment sites resulted in LER average external rotation moment and average posterior force variations (i.e., for all graft tensions at the time of fixation, tibial attachment sites and knee flexions angles) equal to 1.9 N.m (SD 1.3) and 59.2 N (SD 38.7) respectively. The coefficient of variation of the LER external rotation moment and posterior force was between 4.1% and 54.3% depending on the other surgery settings. The sensitivity of LER behavior to the femoral attachment site was the smallest with anterior tibial attachment sites (i.e. near Gerdy's tubercle) when combined with knee flexion angles at the time of fixation smaller than 30°. By contrast, knee flexions angles above 30° combined with a posterior tibial attachment site increased the sensitivity of the LER moment/force to the femoral attachment site (Figure3). Tibial attachment site -Changing tibial attachment sites resulted in LER average external rotation moment and average posterior force variations equal to 2.3 N.m (SD 2.4) and 63.4 N (SD 67.6) respectively. The coefficient of variation of the LER external rotation moment and posterior force was between 0.6% and 67.4% depending on the other surgery settings. The sensitivity of LER behavior to the tibial attachment site was smaller for knee flexions angles between 45 and 60° in comparison to knee flexions angles between 0 and 15°. Posterior and postero-proximal femoral attachment sites with knee flexion angles greater than 45° led to the smallest sensitivity of LER moment/force to the tibial attachment site (Figure4).

9

  Knee flexion angle at the time of graft fixation -Changing knee flexion angle at the time of graft fixation resulted in LER average external rotation moment and average posterior force

  Kinematics of the knee computed from extrapolation of the quasi-static poses are similar to those depicted in previous studies focusing on squat movement. As indicated by Abdel-Jaber et al. (2016) and Miyaji et al. (2012), we observed that knee internal rotation and anterior translation were coupled with knee flexion. To the best of our knowledge, no gold standard data A C C E P T E D M A N U S C R I P T 10 (i.e., intracortical pins or fluoroscopy) are available concerning knee abduction/adduction, cranio/caudal and medio/lateral translation during squat movements. Nevertheless, our results

  U S C R I P T et al. (2017a) compared two LER procedures (ALL and Lemaire) with different tibial

  of fixation on the variability of the control of knee internal and anterior translation during pivot-shift scenarios. Graft tension at the time of fixation ranging between 20 and 40N barely influenced the control of knee stability whatever LER procedure. The influence of the femoral attachment site on the control of knee rotation and translation was reduced if the graft if fixed with the knee near full extension and for tibial attachment sites between ALL location and the Gerdy's tubercle. The choice of tibial attachment site is crucial when the graft is fixed proximally and posteriorly to the femoral epicondyle because large variations in the control of knee rotation and translation was observed. The control of knee rotation and translation has been shown to be sensitive to knee flexion angle at the time of graft fication both for ALL and Lemaire procedures. the standard deviation of the five graft tensions at the time of fixation are represented.

Figure 5 -

 5 Figure 5-Sensitivity (coefficient of variation) of the LER internal moment and posterior force to the knee flexion at the time of fixation with regards to ALL and Lemaire procedures, and the graft tension at the time of fixation. Considering that graft tension barely influence LER internal moment, average values and the standard deviation of the five graft tensions at the time of fixation are represented.

Figure 5

 5 Figure5

Acknowledgment:

We would like to thank Thierry Cresson from the « Laboratoire de recherche en imagerie et orthopédie, École de technologie supérieure, Centre de recherche du Centre hospitalier de l'Université de Montréal »,for his contribution concerning the mesh reconstructions from the biplanar radiographies. In addition, this work was performed within the framework of the LABEX PRIMES (ANR-11-LABX-0063) of Université de Lyon, within the program "Investissements d'Avenir" (ANR-11-IDEX-0007) operated by the French National Research Agency (ANR). Finally, the study was supported by the group "Ramsey Générale de Santé", Paris, France (COS-RGDS-2017-06-014-P-THAUNAT-M).

Conflict of interest statement

Yoann Blache, Raphaël Dumas and Jacques de Guise declare no conflict of Interest.

Mathieu Thaunat, Bertrand Sonnery-Cottet and A.S. are consultant for Arthrex.