Biomechanics of Cranial Cruciate Ligament Reconstruction in the Dog II. Mechanical Properties

Abstract

A biomechanical analysis of the results of an over‐the‐top procedure for replacement of the cranial cruciate ligament (CCL) in the dog is presented. Using 15 adult mongrel dogs, the CCL in one stifle joint was reconstructed using fascia lata and the lateral one‐third of the patellar ligament. The opposite CCL served as the control. Animals were sacrificed at 0, 4, 12 and 26 weeks postoperation and axial failure tests were performed. Stiffness, maximum load, and elastic modulus of the replacement increased over time, while elongation to maximum load continually decreased as compared to controls. Other parameters showed less consistent trends. The results are encouraging given the reduction in joint laxity and the increases in tissue stiffness and strength. However, the ligament substitute was still unable to replicate the mechanical properties of the normal cruciate ligament. Longer studies therefore are required to determine if this replacement is capable of completely restoring joint stability and normal function.

Effect of 9 mm Tibial Tuberosity Advancement on Cranial Tibial Translation in the Canine Cranial Cruciate Ligament‐Deficient Stifle

“…28,129 The maximum force applied before construct failure was 1656 N, with failure occurring midsubstance ligament in 27% of CCLs in one study. 28 In another study, the angle of the stifle affected not only the maximum force before CCL failure, but also whether the failure occurred within the ligament or from the bony attachment points. 137 In full extension, over 1,000 N were required for failure and most of these failed at the tibial insertion point.…”

“…27 In vitro testing of the graft itself, however, demonstrated an increase in strength and stiffness of the tissue as postoperative time increased, suggesting that the autograft function may improve with time. 28 Histologic assessment of the graft showed that it becomes acellular and undergoes necrosis early after placement, but then revascularization occurs from the surrounding synovial fluid which also supplies new fibroblasts. 8 Because of this, severe exercise restriction for the first 2-3 months, with a short term bandage for support, was recommended postoperatively.…”

“…In cadaver experiments, midsubstance rupture occurred in most CCL ruptures at 51 megapascals (MPa)/kg body weight and 148 MPa in two separate studies. 28,129 Some…”

“…The force required to rupture the CCL and ACL was found to be equal in dogs and humans: 1700 newtons. 28,119 Rupture in the midsubstance occurred in most failure tests of cruciate ligaments due to stress dissipation at the enthesis, or insertion site, of the ligament. 130 An alternative method of traumatic CCL rupture is juvenile avulsion of the CCL origin or insertion.…”

Estudo biomecânico de tração (ex-vivo) em osteotomia da tuberosidade tibial de cães estabilizada com placa fixa por "garfo" ou parafuso

“…Entretanto é sabido que a avaliação biomecânica pode trazer informações importantes para estudos clínicos futuros. Os principais estudos biomecânicos realizados até então buscam avaliar implantes e eficácia de técnicas cirúrgica para tratamento de ruptura do ligamento cruzado cranial (ARNOCZKY; TORZILLI; MARSHALL, 1977;BUTLER et al, 1983;NAKAMURA;ELLIS;SEEDHOM, 1985;KOKRON, 2000;HARPER et al, 2004;DENNLER et al, 2006;ROMANO et al, 2006;KIM et al, 2009;GUERRERO et al, 2009;LINS et al, 2009;ETCHEPAREBORDE et al, 2010;GUERRERO et al, 2011 Inúmeras técnicas foram desenvolvidas para tratamento de ruptura de ligamento cruzado cranial em cães, entretanto, ainda não foi estabelecida superioridade de alguma delas baseando-se em evidencias clinicas (MULLEN;MATHIESEN, 2009;SLOCUM, 1993;SHIRES, 1993;KORVICK;SCHAEFFER, 1994;HARARI, 1995;MOORE;READ, 1995;SANDMAN;HARARI, 2001;ARAGON;BUDSBERG, 2005, LAZAR et al, 2005HOFFMANN et al, 2006;POZZI et al, 2006;LAFAVER et al, 2007;ZAMPROGNO, 2007;KIM et al, 2008;VOSS et al, 2008;DYMOND;GOLDSMID;SIMPSON, 2010;VAUGHAN, 2010;KEMPER et al, 2011;...…”