Review Biomechanics of knee ligaments: injury, healing ... curreyj/BNG-345_files/Biomechanics...

download Review Biomechanics of knee ligaments: injury, healing ... curreyj/BNG-345_files/Biomechanics of...Journal of Biomechanics 39 (2006) 1–20 Review Biomechanics of knee ligaments:

of 20

  • date post

    14-Feb-2018
  • Category

    Documents

  • view

    215
  • download

    2

Embed Size (px)

Transcript of Review Biomechanics of knee ligaments: injury, healing ... curreyj/BNG-345_files/Biomechanics...

  • ARTICLE IN PRESS

    0021-9290/$ - se

    doi:10.1016/j.jb

    CorrespondP.O. Box 71199

    E-mail addr

    Journal of Biomechanics 39 (2006) 120

    www.elsevier.com/locate/jbiomech

    Review

    Biomechanics of knee ligaments: injury, healing, and repair

    Savio L.-Y. Woo, Steven D. Abramowitch, Robert Kilger, Rui Liang

    Department of Bioengineering, Musculoskeletal Research Center, University of Pittsburgh, Pittsburgh, PA, 15219, USA

    Accepted 20 October 2004

    www.JBiomech.com

    Abstract

    Knee ligament injuries are common, particularly in sports and sports related activities. Rupture of these ligaments upsets the

    balance between knee mobility and stability, resulting in abnormal knee kinematics and damage to other tissues in and around the

    joint that lead to morbidity and pain. During the past three decades, significant advances have been made in characterizing the

    biomechanical and biochemical properties of knee ligaments as an individual component as well as their contribution to joint

    function. Further, significant knowledge on the healing process and replacement of ligaments after rupture have helped to evaluate

    the effectiveness of various treatment procedures.

    This review paper provides an overview of the current biological and biomechanical knowledge on normal knee ligaments, as well

    as ligament healing and reconstruction following injury. Further, it deals with new and exciting functional tissue engineering

    approaches (ex. growth factors, gene transfer and gene therapy, cell therapy, mechanical factors, and the use of scaffolding

    materials) aimed at improving the healing of ligaments as well as the interface between a replacement graft and bone. In addition, it

    explores the anatomical, biological and functional perspectives of current reconstruction procedures. Through the utilization of

    robotics technology and computational modeling, there is a better understanding of the kinematics of the knee and the in situ forces

    in knee ligaments and replacement grafts.

    The research summarized here is multidisciplinary and cutting edge that will ultimately help improve the treatment of ligament

    injuries. The material presented should serve as an inspiration to future investigators.

    r 2004 Elsevier Ltd. All rights reserved.

    Keywords: Biomechanics; Knee ligaments; Tissue engineering; Healing

    Contents

    1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

    2. Anatomy, histological appearance and biochemical constituents of normal ligaments. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

    3. Tensile properties of ligaments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

    3.1. Ligament anisotropy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

    3.2. Significant biological factors on the properties of ligaments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

    4. Viscoelastic properties of ligaments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

    4.1. The quasi-linear viscoelastic theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

    4.2. Continuum based viscoelastic models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

    e front matter r 2004 Elsevier Ltd. All rights reserved.

    iomech.2004.10.025

    ing author. Department of Bioengineering, Musculoskeletal Research Center, 405 Center for Bioengineering, 300 Technology Drive,

    , Pittsburgh, PA 15219, USA. Tel.: +1 412 648 2000; Fax: +1 412 688 2001.

    esses: ddecenzo@pitt.edu, slyw@pitt.edu (S.L.-Y. Woo).

    www.elsevier.com/locate/jbiomech

  • ARTICLE IN PRESSS.L.-Y. Woo et al. / Journal of Biomechanics 39 (2006) 1202

    5. Healing of knee ligaments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

    5.1. MCL healing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

    5.2. Phases of ligament healing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

    5.3. New animal model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

    6. New approaches to improve healing of ligamentsfunctional tissue engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

    6.1. Growth factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

    6.2. Gene transfer and gene therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

    6.3. Cell therapy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

    6.4. Biological scaffolds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

    6.5. Mechanical factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

    7. ACL reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

    7.1. Graft function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

    7.2. Graft incorporation and remodeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

    8. Future directions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

    Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

    1. Introduction

    Injuries to knee ligaments are very common. It hasbeen estimated that the incidence could be at 2/1000people per year in the general population (Miyasaka etal., 1991) and a much higher rate for those involved insports activities (Bruesch and Holzach, 1993). Ninetypercent of knee ligament injuries involve the anteriorcruciate ligament (ACL) and the medial collateralligament (MCL) (Miyasaka et al., 1991). In fact, recentstudies have documented that ACL injuries in femalesare reaching epidemic proportions with the frequency ofrupture more than 3 times greater than that of their malecounterparts (Anderson et al., 2001; Arendt and Dick,1995; Powell and Barber-Foss, 2000). The results ofligament injuries can be devastating. Frequently, surgeryis required, but the outcomes are variable. Further,post-surgical rehabilitation could require an extendedabsence from work or athletic competition.

    Basic science and clinical studies have revealed that aruptured MCL can heal spontaneously (Frank et al.,1983; Indelicato, 1983; Jokl et al., 1984; Kannus, 1988).However, laboratory studies have shown that itsultrastructure and biochemical composition remainsignificantly altered (Frank et al., 1983; Niyibizi et al.,2000; Weiss et al., 1991). Furthermore, the mechanicalproperties of the ligament substance remain substan-tially inferior to those of normal ligaments even afteryears of remodeling (Loitz-Ramage et al., 1997; Ohlandet al., 1991). On the other hand, midsubstance tears ofthe ACL and posterior cruciate ligament (PCL) wouldnot heal spontaneously and surgical reconstructionusing a replacement graft is often required (Hirshmanet al., 1990; Kannus and Jarvinen, 1987). While the

    majority of ligament reconstructions yield good short-term clinical results, 2025% of patients experiencecomplications including instability that could progres-sively damage other knee structures (Aglietti et al., 1997;Bach et al., 1998; Daniel et al., 1994; Jomha et al., 1999;Ritchie and Parker, 1996; Shelbourne et al., 1995; Yagiet al., 2002).

    Thus, there has been a tremendous quest for knowl-edge to better understand ligament injuries, healing andremodeling in hope to develop new and improvedtreatment strategies. The needs in meeting this goalhave stimulated researchers to seek new and innovativemethods of investigation. Because of the complexbiological process, it has become clear that collabora-tions from different disciplines rather than an indivi-dualistic approach in research must be developed. In thisreview, the properties of normal ligaments, includingtheir anatomical, biological, biochemical and mechan-ical properties, as well as the changes that occurfollowing injury will be described. The MCL will beused as a model because of its uniform cross-sectionalarea, large aspect ratio, and propensity for healing.Subsequently, novel functional tissue engineering meth