LAB 142 - Implants for Ligament & Tendon Reconstruction - Product Portfolio

Neoligaments™A division of Xiros™Springfield HouseWhitehouse LaneLeeds LS19 7UE UK

Tel. +44(0)113 238 7202Fax. +44(0)113 238 [email protected]

Registered in England No.1664824

Neoligaments, Xiros, Poly-Tape,Ortho-Tape MPFL System, Jewel ACL,Rota-Lok, AchilloCordPLUS and Fastlokare trademarks of Xiros.

All rights reserved © Neoligaments™2010. Worldwide patents and patentspending.

LAB 142 A

The design and science behind why they work

Implants forLigament & TendonReconstruction

4175 Neoliagments Tech product 210sq:Layout 1 7/9/10 16:10 Page 1

The Neoligaments product portfoliocomprises textile implants andfixation devices. The textile implantsfall into two types: general devicesand speciality devices.

General devicesThe general devices are intended to be used for anysoft tissue approximation. They are available in a rangeof standard sizes, between 3 mm and 50 mm wide andin various lengths. They are available in two shapes: asingle thickness flat tape, or a double thickness (tube).Each of these may have an open or dense structure.The strength increases with width to improve theresistance to failure. The surgeon can select from thisrange the device best suited to the repair. Such devicesinclude the Poly-Tape and Ortho-Tape.

Speciality devicesSpeciality devices are those which have been optimizedto repair a particular tissue. These include the Rota-Lok™, for reconstruction of massive rotator cuff tears,and JewelACL™, for anterior cruciate ligament (ACL)reconstruction. These devices typically include a mix ofspecific structural features such as sections of openand dense weave, pockets, or cords for pulling theimplant through bone tunnels. The dimensions, strength and stiffness characteristics of these devicesare biomechanically designed to suit their intendedapplication. This ensures the implant can withstand the load placed on it without failure and permits correct load transfer to encourage tissue ingrowth and remodelling.

Textile Implants

General Speciality

Fixation Devices

Product Portfolio

Poly-Tape AchilloCordPlus Rota-Lok JewelACL FastLok

Device: Fixation DeviceSize: 6 & 8 mmShape: N/AStructure: N/AFinish: N/AConstruction: Ti

Device: Textile implantType: GeneralSize: 5 x 500 mm to

50 x 800 mmShape: FlatStructure: OpenFinish: StandardConstruction: Weave

Device: Textile implantType: SpecialitySize: 10 x 500 mmShape: FlatStructure: Open / DenseFinish: StandardConstruction: Weave

Device: Textile implantType: SpecialitySize: 7 x 710 mmShape: Flat / TubeStructure: Open / DenseFinish: PlasmaConstruction: Weave

Device: Textile implantType: SpecialitySize: 5 x 800 mmShape: Flat / TubeStructure: DenseFinish: StandardConstruction: Weave

Ortho-Tape

Device: Textile implantType: GeneralSize: 3 & 400/600 mmShape: FlatStructure: DenseFinish: StandardConstruction: Weave


foot & Ankle• Achilles tendon• Peroneal tendon stabilization• Lateral ankle ligament*• Repairing fail foot*

Knee• Patellar tendon• Quadriceps tendon• Anterior cruciate ligament (ACL)• Posterior cruciate ligament

(PCL)*• Medial patellofemoral ligament

(MPFL)• Tibial/femoral fixation of ACL/PCL

grafts*• Medial collateral ligament (MCL)*• Lateral collateral ligament (LCL)*• Popliteal tendon*• Reattaching muscles to a tumour

endoprosthesis*

* Neoligaments has not clinically evaluated those procedures marked with an asterisk and does not currently supply a surgical technique manual for them. However, the use of the Poly-Tape for such procedures has been reported at conferences and in medical journals.

Hip• Iliofemoral ligament*• Reattaching muscles to a tumour

endoprosthesis*

Shoulder• Rotator cuff• Acromioclavicular joint and

coracoclavicular ligaments• Antero-inferior gleno-humeral

ligament capsular reinforcement• Augmented subscapularis

muscle transposition for rotator cuff repair during shoulder arthroplasty*

The Neoligaments product portfolio is versatileand surgeons have used these implants for repairor reconstruction of many ligaments and tendonsin the joints of both the lower and upper limbs.

Applications


Textile implants offermany benefitsThe factors that made textile implants soappealing when they were first introducedremain as relevant and valid as ever. Theiruse for ligament and tendon reconstructionoffers the following benefits:

• they remove the need for harvesting autologous tissues and so eliminate the pain, muscle deficiency and donor site morbidity associated with the harvesting procedure;

• where they are used instead of allografts, the risk of cross infection is eliminated;

• their use shortens the surgical procedure by the time consumed in graft harvesting and/or preparation;

• textile implants offer consistency as they have uniform properties and dimensions whereas tissue grafts vary in both properties and dimensions;

• textile implants retain their initial strength, which is sufficient to permit earlier weight bearing and earlier return to activities than do tissue grafts because of the debilitating necrotic stage they go through, when they loose much of their strength that is recovered over a long period postoperatively;

• because textile implants are readily available in abundance they facilitate complex reconstruction procedures where a recipient has sustained multiple injuries to ligaments in one joint.

Manufactured frompolyester, a materialwith many years ofimplant historyThe Neoligaments textile implants aremanufactured in-house, at dedicatedmanufacturing sites in the UK, frompolyethylene terephthalate (PET) which iscommonly know as polyester. Polyester hasmechanical properties which, with carefuldesign, can match the strength and stiffnessof natural tissue. It is therefore ideal for themanufacture of implants for ligaments and tendons.

This nonabsorbable material is one of themost common polymers to be used inmedical implants. For more than 40 yearsit has been utilized in the manufacture ofarterial grafts and aortic implants. It hasbeen used for fixation of ACL grafts(EndoButton Continuous Loop, Smith & Nephew) for over 10 years, for ligaments for over 25 years and for sutures for over 70 years.


3000

2000

1000

0 ACLNative tissue

Strength (N)

ESP3000Leeds-Keio

The implants possesshigh strength so canallow early rehabilitationThe textile implants have been thoroughly testedto determine their initial strength and stiffnesscharacteristics and their response to simulatedexercise. As an example, the NeoligamentsESP3000 ACL ligament which is used for youngactive patients, has undergone cyclic testingequivalent to both one and six years of simulatedexercise from implantation. The resultsdemonstrate that the implant can withstand theloads placed on it without failure. It also indicatesthat the stiffness is similar to that of the naturalACL so permits correct load transfer toencourage cell growth.

4000

Stiffness (N/mm)

The structure provides a scaffold for tissueingrowthNeoligaments textile implants are predominantlyof woven construction, comprising parallellongitudinal (warps) and transverse (weft) fibreswhich cross at right angles. The implantstypically possess an “open structure” that actsas a scaffold allowing bone and tissue ingrowth.This new tissue protects the device fromabrasion and, as it matures, it providesadditional strength. This “scaffold” implant is notto be confused with the “permanent type”implant, such as the Gore-Tex device, which isdesigned to last a lifetime with no contributionfrom the host tissue or new tissue growth.

All our implants arebiologically safeThe process of manufacturing ensures thatthe implants are free from contaminantsbefore they are supplied, sterile with gammairradiation, in sealed double blister or pouchpackages. The intended shelf life of theproduct has been validated.

The products have been thoroughlyevaluated for biological safety using a rangeof tests following ISO 10993-1 Biologicalevaluation of medical devices – Part 1:Evaluation and testing within a riskmanagement process. A quarter of acentury of extensive clinical use withextremely low levels of reported problems is evidence of the outstanding safety of the products.

Our unique plasmatreatment processspeeds cell growthSelected textile implants are subjected to a proprietary low-power cold gas plasmatreatment process. This forms oxidized chemical groups on the material surface, turning the standard hydrophobic polyester into a hydrophilic material.

This has a dramatic effect, increasing the speedand extent of cell recruitment and theiradherence to the implant. In vitro studies havefound that tissue ingrowth is approximately fourtimes faster [Rowland et al. 2003; Tsukazaki etal. 2003]. Prompt tissue growth has also beennoted clinically via postoperative arthroscopy,biopsy and transmission electron microscopestudies on scaffold textile implants used for ACLreconstructions [Sugihara et al. 2006].

Scanning electron microscopy (SEM) showing portions ofcontrol (left) and plasma treated (right) polyester scaffoldsfive days after incubation. Note the greater coverage of thetreated materials by synovial stromal cells.


Both pre-clinical andclinical studies haveconfirmed that theNeoligaments “open”structure provides ascaffold for tissueingrowth

Pre-clinical studiesNumerous studies have reported oninduction and remodelling processes oftissue ingrowth into the structure of thescaffold implant. Of these, two wereundertaken in a canine model [Fujikawa etal. 1993]. The figures (right) briefly describethe salient findings of the first study, whichwas undertaken on 13 animals and spanned36 weeks. The second investigated differentsurgical techniques in a series of 60animals. Of particular interest are thefindings concerned with the ligament-bonejunction, the morphology and histology ofwhich revealed an abundance of Sharpey’sfibres that adjoined the newly formed softtissue to the bone. Fibrocartilage withchondrocytes was also observed and therewas evidence of the four layers commonlyfound in the normal ligamentous andtendinous junction to the bone.

The natural canineACL

(Top) Morphology has a superficialvascular network – highlighted by the blue acrylic dye.

(Bottom) Histology shows denselyaligned collagen interspersed with fewcells that are spindle shaped.

8 weekspostoperatively

(Top) The implant is surrounded withtissue that is hypervascular.

(Bottom) The histology shows a randomand hypercellular structure. The cells areof an oblate morphology.

24 weekspostoperatively

(Top) Vascularity is greatly reduced in thenew tissue that completely surrounds theimplant seen through the tunnel in thetibia.

(Bottom) The tissue is better organized,with reduced cellularity. Most of the cellshave differentiated into the spindle formtypical of ligament fibroblasts.

32 and 36 weekspostoperatively

Most salient offindings

For the tissue remodelling procedure tooccur, it is essential that the cells withinthe scaffold experience repeated tensilestrain. For this strain to occur, theligament must be correctly placed, tautand securely anchored. Both ligaments in the pictures have been implanted for12 weeks. A slack reconstructed ligament(bottom) does not experience any tensilestrains and so induced tissue would notremodel as in a taut ligament (top).

(Top and bottom respectively) The newtissue has remodelled further intoligament-like tissue, with even morereduced cellularity.


Clinical studiesAn arthroscopic study [Fujikawa et al. 1989]reported on 42 recipients of the Leeds-KeioACL ligament, who had a mean age atoperation of 23.5 years, and were followedup at 3 to 24 months postoperatively.Biopsies on 19 of the implants were taken at 3, 6, 12 and 18 months. At 3 months,arthroscopy showed the implant covered in tissue with a dense vascular network. By 6 months there were synovial cordsrunning along the length of the implant. By 8 months the tibial insertion hadremodelled and become broader and fanshaped. The implant was tight throughoutthe range of motion (ROM). By 12 monthsthe reconstruction appeared like the naturalligament in terms of shape and thickness,with reduced vascular network on it’ssurface. By 12 to 18 months the histologyrevealed large quantities of parallel collagenous fibres running in thedirection of loading. However, more cellswere present than would be found in normalligamentous tissue. At 18 to 24 months the reconstruction could be mistaken fora natural ligament. Where an implant was

slack the tissue was fibrotic and immature.The process of tissue induction andremodelling observed in the human modelis identical to that observed in the canine,except it is much slower.

In another paper [Zaffagnini et al. 2008], the authors performed a histological andultrastructural evaluation of an intact Leeds-Keio ACL ligament that had been implantedfor over 20 years. Arthroscopic evaluation ofthe intra-articular portion of the Leeds-KeioACL ligament revealed a completelycovered implant that was stable duringdrawer test, was well fixed at insertion and stable during palpation.

Tissue ingrowth in the Neoligamentsscaffold implants has been reported innumerous other publications including extra articular applications such as medial patellofemoral ligament (MPFL)reconstruction [Nomura et al. 2005]. Further information can be can be found in the document “Neoligaments Scientific Articles” (LAB 144).

Arthroscopic appearance of the tissue inducedaround the scaffold implant in a reconstructed ACLat 12 months postoperatively.

The histology of a reconstructed ACL at 12 monthspostoperatively. It shows a crimped structure typicalof normal collagen, but with a looser and somewhathypercellular structure. The orientation of the fibres is longitudinal and parallel.

Mr Kenji InoeuOccupation: Professional Freestyle wrestler

Country: Japan

Surgery: Bilateral ACL reconstruction using Leeds-Keio ACL ligament and Poly-Tape.

Outcome: At 26 years of age, as a result of injuries sustained in trainingsessions and matches, Kenji suffered ACL ligament rupture in both knees. This resulted in severe knee instability which prevented him from wrestling. Treatment was undertaken by Professor Fujikawa at the National Defense Medical School (NDMS) clinic, initially with the reconstruction of his left knee,followed by the right knee three months later. Only two months after the second operation he returned to sport specific training at the Japanese national training camp for free style wrestling. Six months and three weeks after the operation he participated in the All Japan Open Wrestling Games, winning first prize. Two years and seven months postoperatively he won the second prize at the All Japan Wrestling Games. Three years after the operation he won the bronze medal in the Men's Freestyle 60kg at the 2004 Summer Olympics.

Mr Yoshihiro NakaoOccupation: Professional Freestyle wrestler.

Country: Japan

Surgery: ACL reconstruction using Leeds-Keio ACL ligament and Poly-Tape.

Outcome: At 22 years of age Yoshihiro sustained an injury to his right knee joint during training. A ruptured ACL was diagnosed but was treated conservatively and training was resumed. A second injury to the joint was soon sustained, preventing any further training. The subject was referred to Professor Fujikawa at the NDMS clinic for ACL reconstruction to the right knee. Two months after the operation, training was resumed. Seven months and two weeks postoperatively he participated in the All Japan wresting games, where he achieved second place. However, three years after the operation he again suffered injury to his right knee joint. Following arthroscopic examination a meniscal tear was observed, which was repaired accordingly. It was further observed that the ACL reconstruction was unaffected by the injury, had good tension and was completely covered with autogenous tissue giving the appearance of an original ACL. Yoshihiro was able to resume his professional career. Mr Andrew Young

Country: UK

Surgery: Achilles tendon repair with AchilloCord™.

Outcome: “After three weeks of pain I saw Dr Steel on 5 June who immediately recognised the problem and quickly referred me to Darlington Memorial Hospital (DMH) where I saw Mr Duffy on 7 June. Following an ultrasound scan, he took the trouble to refer me on to Mr Jennings, Consultant Orthopaedic Surgeon, North Durham, who saw me on 8 June and agreed to operate on 12 June. The ligament reconstruction saved me from weeks in plaster and meant I was able to enjoy my summer tour of France. Although I am still having physiotherapy the operation has been a great success.”

Mr TimmCountry: UK

Surgery: Achilles tendon repair with Poly-Tape.

Outcome: Mr Timm was initially treated in Scunthorpe with a plaster cast which resulted in a poor repair. He had difficulty in working, walking and driving as his Achilles tendon hadn’t healed. The injury was therefore revised by Mr Jennings, Consultant Orthopaedic Surgeon, North Durham, with a surgical procedure using the AchilloCord. Mr Timm commented, “Fantastic! Two weeks after surgery I’m walking in normal shoes without a plaster!

Case Studies


References

HISTOLOGY

Fujikawa K, Seedhom BB, Matsumoto H,Kawakubo M,Otani T. The Leeds-Keio ligament.In: Strover A, editor. Intra-articular reconstructionof the anterior cruciate ligament. London:Butterworth Heinemann, 1993:173-207.

Fujikawa K, Iseki F, Seedhom BB. Arthroscopyafter anterior cruciate reconstruction with theLeeds-Keio ligament. J Bone Joint Surg Br.1989;71(4):566-570.

Zaffagnini S, Marcheggiani Muccioli GM,Chatrath V, Bondi A, De Pasquale V, Martini D,Bacchelli B, Marcacci M. Histological andultrastructural evaluation of Leeds- Keio ligament20 years after implant: a case report. Knee SurgSports Traumatol Arthrosc. 2008;16(11):1026-1029.

Nomura E, Inoue M, Sugiura H. Histologicalevaluation of medial patellofemoral ligamentreconstructed using th Leeds-Keio ligamentprosthesis. Biomaterials. 2005;26 (15):2663-2670.

PLASMA TREATMENT

Rowland JR, Tsukazaki S, Kikuchi T, Fujikawa K,Kearney J, Lomas R, Wood E, Seedhom BB.Radiofrequency-generated glow dischargetreatment: potential benefits for polyesterligaments. J Orthop Sci.2003;8(2):198-206.

Tsukazaki S, Kikuchi T, Fujikawa K, Kobayashi T,Seedhom BB. Comparative study of the coveredarea of Leeds-Keio (LK) artificial ligament andradio frequency generated glow dischargetreated Leeds-Keio (Bio-LK) ligament withsynovial cells. J Long Term Eff Med Implants.2003;13(4):355-362.

Sugihara A, Fujikawa K, Watanabe H, MurakamiH, Kikuchi T, Tsukazaki S, Aoki Y, Matsunaga M,Nemoto K. Anterior Cruciate Reconstruction withBioactive Leeds- Keio Ligament (LKII): PreliminaryReport. J Long Term Eff Med Implants.2006;16(1):41-49.

LOWER LIMB

Jones AP, Sidhom S, Sefton G. Long-termclinical review (10-20 years) after reconstructionof the anterior cruciate ligament using the Leeds-Keio synthetic ligament. J Long Term Eff MedImplants. 2007;17(1):59-69.

Toms AD, Smith A, White SH. Analysis of theLeeds-Keio ligament for extensor mechanismrepair: favourable mechanical and functionaloutcome. Knee. 2003;10 (2):131-134.

Jennings AG, Sefton GK. Chronic rupture oftendo Achillis. Long-term results of operativemanagement using polyester tape. J Bone JointSurg. 2002;84B (3):361-3.

Jennings AG, Sefton GK, Newman RJ. Repair ofacute rupture of the Achilles tendon: a newtechnique using polyester tape without externalsplintage. Ann R Coll Surg Engl. 2004;86(6):445-8.

Nomura E, Horiuchi Y, Kihara M. A mid-termfollowup of medial patellofemoral ligamentreconstruction using an artificial ligament forrecurrent patellar dislocation. Knee.2000;7(4):211-5.

Usami N, Inokuchi S, Hiraishi E, Miyanaga M,Waseda A. Clinical application of artificialligament for ankle instability--long-term follow-up. J Long Term Eff Med Implants. 2000;10(4):239-50.

UPPER LIMB

Sanchez M, Cuellar R, Garcia A, Albillos J,Azofra J. Anterior Stabilization of the Shoulder byMeans of an Artificial Capsular Reinforcementand Arthroscopy - Part II: Results. J Long Term EffMed Implants. 2000;10 (3):199-209.

Nada A, Rogers C, Debnath U. Dacron ligamentaugmentation of massive rotator cuff tear. AAOS75th Annual Meeting Poster Presentations. SanFrancisco. 2008:P313.


Documents

LAB 142 - Implants for Ligament & Tendon Reconstruction - Product Portfolio