Biomechanical Properties of the Anterolateral Ligament (ALL) of the Knee compared with that of the Iliotibial tract (ITT)

K.Elmajri †

D. Mitton and ‡ S. Lustig ‡ Université de Lyon, F-69622, Lyon, France; Université Claude Bernard Lyon 1, Villeurbanne, France; IFSTTAR,

UMR_T9406, LBMC Laboratoire de Biomécanique et Mécanique des Chocs, F69675, Bron, France;

Keywords: Knee; Anterolateral ligament; Biomechanics; Cadaveric.

1. Introduction The Anterolateral Ligament1 (ALL) of the Knee was recently rediscovered as 2 distinct structure3 4. ALL anatomy study by dissection and imaging is reported with no complete consensus5 6 7 8 9 10 . ALL biomechanics remains largely undetermined. IlioTibial Tract (ITT) is an old substitute in the knee surgery 11 12 13 14 15. ITT biomechanical properties were established in the literature16 17 18 19. Determination of ITT properties was performed using cadaveric material chemically fixed20. The fixation method alters tissues properties 21 22 23 including those of ITT24.

Figure1- Relationship between ALL anterolateral

ligament - FCL fibular collateral ligament-and ITT iliotibial tract (reflected) of left knee.

The purpose of this study is to compare biomechanical properties of ALL and ITT both as fresh and embalmed cadaveric specimens. Two hypothesis are studied: 1-ALL is a prime stabiliser of the rotational instability of the knee25 , ALL would be reconstructed, when indicated, using ITT26 and 2: Softbalm does not alter the biomechanical properties of the tissues ALL nor ITT. 2.MethodsA total of 24 ligaments from 12 cadaveric specimens (Department Universitaire d’Anatomie Rockefeller) will be considered in this study. The same dissections technique will27 be followed and documented by pictures for all specimens.

ALL prepared as bone-ligament-bone specimens, ITT as bone–ligament specimen. Specimens are divided into 4 groups. 1st and 2ed groups contain ALL and ITT harvested from fresh cadaver subjects, 3rd and 4th

contain ALL and ITT harvested from the same cadaver subjects 2 weeks after embalming with (Softbalm). A random sampling is applied for right and left knee. The comparison is done between ALL and ITT in each group and between the same ligament in different groups. Specimens will be subjected to uniaxial load up to a strain of 100% of the initial length at a velocity of ~35 mm/s-128.

Figure 2- uniaxial load of ALL.

Low preload will be applied to avoid laxity in the tissue at the start of testing29. Specimens will be loaded up to failure. Global strain will be computed from the entire grip-to grip displacement measured by the machine transducer (INSTRON 8802). Local strain of ligaments will also be measured by image correlation method. The tensile load will be measured by a specific transducer (TME).

3. Expected results and DiscussionALL found to be prime stabiliser of the rotational instability of the knee30. Discuss the possibility that ITT substitute ALL.

1

Figure 2- Dissection of ALL anterolateral ligament - FCL fibular collateral ligament- FC femoral

epicondyle - FH fibular head - ITT iliotibial tract (reflected) –LM lateral meniscus -MFL

meniscofemoral ligament.

4. ConclusionsThe ALL found to be associated with avulsion fracture (or Segond fracture)31 and there is a correlation between adduction laxity at 30° of knee flexion and Segond fracture32.

Biomechanical properties

ALLFresh

ITTFresh

ALL Embalmed

ITTEmbalmed

Maximum load (N)Maximum load per Unite Width N/mmMaximum Stress MPaStiffness KN/mStiffness/Width KN/m/mm

Biomechanical properties

ALLFresh

ITTFresh

ALL Embalmed

ITTEmbalmed

Maximum load (N)Maximum load per Unite Width N/mmMaximum Stress MPaStiffness KN/mStiffness/Width KN/m/mm

Table (1) Expected tensile properties of ALL and ITT.

Determination of biomechanical properties of ALL (Table 1) is a prerequisite to allow its correct use in extra-articular reconstruction 33 34 when combined intra and extra articular ACL reconstruction is indicated to restore the normal knee stability35. Further studies comparing the mechanical properties related to function of different parts are needed to understand the kinematics of the knee.

References

2

3

1 Vincent JP et al, 2012, Knee Surg Sports Traumatol Arthrosc, 20(1):147-52. 22 Riccardo Gomes Gobbi et al, 2013, Orthopaedic Journal Of Sports Medicine.3 Camilo Partezani Helito et al, 2014, Am J Sports Med. 4 Rezansoff Aj et al, 2014, Knee Surg Sports Traumatol Arthrosc.  .5 James H. Lubowitz et al, 2014,The Journal of Arthroscopic and Related Surgery, Vol 30, No 11 pp 1385-1388.6 Caterine S et al, 2014, Knee Surg Sports Traumatol Arthroscopy.7 Camilo Partezani Helito et al, 2014 , Skeletal Radiology ,Volume 43, Issue 10, Pp 1421-1427.8 Gossner J et al, 2014,Rev Bras Ortop. 9 Steven Claes et al, 2014, J. Arthro.2014.05.039.10 Glenn C. Terry, Robert F. La Prade, 1996, Am J Sports Med January 1996 vol. 24 no. 1 2-8 .11 Riccardo Gomes Gobbi et al, 2013, Orthopaedic Journal of Sports Medicine.12 Noyes FR et al, 1984, J Bone Joint Surg Am.,Mar; 66(3):344-52.13 Masayoshi Yagi et al, 2002 The American Journal Of Sports Medicine, Vol. 30, No. 5. 14 R. C. Bray et al, 1988, Bone And Joint Surgery J Bone Joint Sung [Br] ;70-B:Loo-S.15 S. Rackemann et al,1991, J Bone Joint Surg [Br] ; 73-B :368-73.16 A. L. Dodds et al , 2011Bone Joint Surg Br vol. 93-B no. 11 1440-1448.17 Zarzycki W et al ,1999, Chir Narzadow Ruchu Ortop Pol.64(3):293-302.18 Rajat Saran, 2010, People’s Journal of Scientific Research 11 Vol.3 (2).19 P. B. Rauh et al, 2010, J Bone Joint Surg [Br] ; 92-B: 1460-5..20 F.Q. Pancheri et al, 2014, journal of the mechanical behavior of biomedical materials, 306–323.21 K. Birnbaum et al, 2004, Surg Radiol Anat 26: 433–446.22 Niels Hammera et al, 2012, journal of the mechanical behavior of biomedical materials 81–86.23 Joseph Hamill et al, 2008, Clinical Biomechanics 1018–1025.24 Erich Brenner, 2014,J. Anat 224, pp316--344.25 Gobbi et al , 2013, Orthopaedic Journal of Sports Medicine vol. 1 no. 7 26 P. B. Rauh et al, 2010, J Bone Joint Surg [Br];92-B:1460-5.27Leon Van der Watt, 2015, Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 3: pp 569-582.28 Michael W.R. Holme et al, 2012, Journal of Orthopaedic Research. 29Horst Czichos et al, 2006, Library of Congress Control Number: 2006 921595, ISBN-10: 3-540-20785-6.30 Hans-Joachim Wilkea et al, 2011, Journal of the Mechanical Behavior of Biomedical Materials, Volume 4, Issue 8, Pages 2133–2137.31 Gion Fessel Kevin Freya et al, 2011Annals of Anatomy 193 237–241.32 Unger Stefan et al, 2010, Bone 47 ,1048–1053.33 Hanno Steinke et al, 2012, Medical Engineering & Physics 34, 1221–1227.34 Mehdi Benkhadra et al, 2011, Surgical and Radiologic Anatomy, Springer Verlag (Germany), 33, pp.365-368.35 Bertrand Sonnery-Cottet et al, 2015, Am J Sports Med.