Comparative Analysis of the Structural Properties of the Collateral Ligaments of the Human Knee

Abstract

T he passive stability of the knee is primarily provided by a complex system of intra-and extra-articular ligaments that resist anterior and posterior translation, abnormal tibial rotation, and varus and valgus rotation. Functionally, the medial collateral ligament complex (MCL) acts as the primary restraint to valgus rotation of the tibia, providing as much as 80% of the restraining force to valgus loads. 11 The lateral collateral T T STUDY DESIGN: Controlled laboratory study. T T BACKGROUND:Varus knee instability arising from lateral collateral ligament (LCL) injury increases stress on cruciate ligament grafts, potentially leading to failure of reconstructed ligaments. In contrast to the medial collateral ligament (MCL), little is known about the structural properties of the LCL. T T OBJECTIVES:To compare the tensile properties of the LCL and MCL complex of the human knee joint. T T METHODS:Ten fresh-frozen cadaveric knees (mean  SD age, 81  11 years), free of gross musculoskeletal pathology, were obtained. Following dissection, the length, width, and thickness of the ligaments were measured using calipers, and bone-ligament-bone preparations were mounted in a uniaxial load frame. After preconditioning, specimens were extended to failure at a rate of 500 mm/min (approximately 20%/s). Force and crosshead displacement were used to calculate structural properties, including stiffness, yield strength, ultimate tensile strength, and failure energy. T T RESULTS:The fan-shaped MCL was significantly longer (60%; P<.001), wider (680%; P<.001), and thinner (19%; P = .009) than the cord-like LCL.The LCL failed at either the fibular attachment (n = 6) or midsubstance (n = 4), while failure of the MCL primarily occurred at the femoral attachment (n = 7). Although the ultimate tensile strength of the MCL (mean  SD, 799  209 N) was twice that of the LCL (392  104 N; P<.001), there was no significant difference in stiffness of the ligaments (MCL, 63  14 N/mm; LCL, 59  12 N/ mm). 30 During normal gait, the LCL is the primary passive structure resisting the knee adduction (varus) moment, which has been implicated in the progression of knee osteoarthritis. T T CONCLUSIONS: 31While isolated ligamentous injury of the knee often involves the MCL, traumatic sports injuries can affect multiple knee ligaments.1 Concomitant injury to the posterolateral structures is often unrecognized in patients with multiple ligament or combined ligament disruptions.12,22 Abnormal varus laxity arising subsequent to injuries of the LCL and other posterolateral structures has been shown to increase stress on cruciate ligament grafts, and has been implicated as one of the causes of failed cruciate ligament reconstructions. 12,19 Unlike the MCL, animal models have demonstrated that the LCL heals poorly when torn, 20 and, consequently, surgical repair or reconstruction of the LCL is often advocated with acute grade III injuries, particularly when multiple posterolateral structures are involved.14 Although sparse data are available concerning the c...

Posterior tibial slope and femoral sizing affect posterior cruciate ligament tension in posterior cruciate-retaining total knee arthroplasty

“…1). The stiffness coefficients of the anterior-lateral PCL, posterior-medial PCL, LCL, anterior MCL, and posterior MCL were set at 102, 102, 59, 63, and 63 N/mm, respectively, based on reported values (Harner et al, 1995;Robinson et al, 2005;Sugita and Amis, 2001;Wilson et al, 2012). The length and slack of each ligament throughout its range of motion were finely adjusted so that the length patterns of the ligaments were similar to those reported by a previous cadaver study (Fig.…”

The challenges of measuring in vivo knee collateral ligament strains using ultrasound

“… a Pang and Ying, 2006, b Mello et al, 2006, c Cook et al, 1998, d Dundon et al, 2012, e Stenroth et al, 2012, f Wiesinger et al, 2016, g Wilson et al, 2012, h Zooker et al, 2012 …”

Aging affects mechanical properties and lubricin/PRG4 gene expression in normal ligaments

“…Likewise, Woo et al (1991) found that human ACL stiffness and ultimate force were decreased with age using three age groups: 22-35 years, 40-50 years, 60-97 years. More recent studies of the human medial collateral ligament (MCL) have cautioned that, similar to the ACL, strength and stiffness that were measured only assessing older MCLs may underestimate the strength and stiffness of younger MCLs (Robinson et al, 2005;Wilson et al, 2012).…”