The variation in medial and lateral collateral ligament strain and tibiofemoral forces following changes in the flexion and extension gaps in total knee replacement

Abstract

Achieving deep flexion after total knee replacement remains a challenge. In this study we compared the soft-tissue tension and tibiofemoral force in a mobile-bearing posterior cruciate ligament-sacrificing total knee replacement, using equal flexion and extension gaps, and with the gaps increased by 2 mm each. The tests were conducted during passive movement in five cadaver knees, and measurements of strain were made simultaneously in the collateral ligaments. The tibiofemoral force was measured using a customised mini-force plate in the tibial tray. Measurements of collateral ligament strain were not very sensitive to changes in the gap ratio, but tibiofemoral force measurements were. Tibiofemoral force was decreased by a mean of 40% (SD 10.7) after 90 degrees of knee flexion when the flexion gap was increased by 2 mm. Increasing the extension gap by 2 mm affected the force only in full extension. Because increasing the range of flexion after total knee replacement beyond 110 degrees is a widely-held goal, small increases in the flexion gap warrant further investigation.

Elongation of the collateral ligaments after cruciate retaining total knee arthroplasty and the maximum flexion of the knee

“…In the AP of the LCL, the elongation was increased by 0.9 75.9% compared to that of the OA knees at the maximal flexion of the knee. The increases of the lengths of the collateral ligaments with flexion of the knee after TKA were also reported in other studies of the MCL (Jeffcote et al, 2007;Thompson et al, 2011) and LCL (Delport et al, 2013). Even though the change of ligament length was not shown to be significant in maximum flexion, the correlation analysis indicated that for individual patients, an overstretching of the collateral ligaments at high flexion angles, especially the anterior portions of the ligaments, strongly correlated to the reduction of the maximal flexion of the knee when compared to the pre-operative knee flexion.…”

“…Although numerous studies have investigated on the kinematics of the knee after TKA surgeries (Bertin et al, 2002;D'Lima et al, 2001D'Lima et al, , 2000Delport et al, 2013;Fantozzi et al, 2006;Hamai et al, 2009;Li et al, 2004a;Most et al, 2003;Moynihan et al, 2010;Qi et al, 2013;Saari et al, 2005;Yue et al, 2011), the information regarding the collateral ligaments of TKA knees has been reported in few studies (Delport et al, 2013;Ghosh et al, 2012;Jeffcote et al, 2007;Konig et al, 2011;Thompson et al, 2011) and only two studies investigated the lengths of collateral ligaments after TKAs (Ghosh et al, 2012;Konig et al, 2011). Konig et al (Konig et al, 2011) measured the distances between attachments of anterior or posterior portion of the collateral ligaments using computer models, and reported that the distances of anterior MCL increased and anterior LCL remained constant, while those of posterior portion of MCL and LCL decreased with knee flexion.…”

“…However, the influence of the biomechanics of the collateral ligaments at higher flexion on knee function is not well understood. There are only limited studies of the MCL and LCL in TKA knees (Delport et al, 2013;Ghosh et al, 2012;Jeffcote et al, 2007;Konig et al, 2011;Thompson et al, 2011) with few reporting length changes of the MCL and LCL using computer models or cadaveric specimens (Ghosh et al, 2012;Konig et al, 2011). The biomechanics of the MCL and LCL along the Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jbiomech www.JBiomech.com functional flexion path of the knee after TKA has not been reported.…”

Geometrical changes of knee ligaments and patellar tendon during passive flexion

“…The present lengthening of portions of the LCL was similar to that of other studies (Harfe et al, 1998;Meister et al, 2000;Park et al, 2005), as well as the general isometric behaviour of the AB-MCL (Harfe et al, 1998;Park et al, 2005). Comparisons are also difficult because of the representation of the ligament changes in length: this was reported in millimetres (Ahmad et al, 2003;Bergamini et al, 2011;Park et al, 2005), the reference length was that at knee full extension (Bergamini et al, 2011;DeFrate et al, 2007;Feeley et al, 2009;Grood et al, 1989;Hefzy et al, 1989;Robinson et al, 2009;Zavras et al, 2001), and different normalisations were operated (Blankevoort et al, 1991;Jeffcote et al, 2007;Zavatsky and O'Connor, 1992). Simple two-dimensional analyses were also reported (Lu and O'Connor, 1996a;O'Connor et al, 1989;Zavatsky and O'Connor, 1992).…”

“…A number of studies, both in-vivo and in-vitro, have focussed on the contribution to knee joint mobility of relevant single sub-bundles of the anterior (ACL) and posterior (PCL) cruciate ligaments (Blankevoort et al, 1991;DeFrate et al, 2004;Hefzy et al, 1989;Hosseini et al, 2009;Grood et al, 1989;Li et al, 2005;O'Connor, 1996a, 1996b;Zavatsky and O'Connor, 1992), of the medial (MCL) and lateral (LCL) collateral ligaments (Feeley et al, 2009;Gardiner et al, 2001;Harfe et al, 1998;Jeffcote et al, 2007;Park et al, 2005), and also of several portions of the patellar tendon (PT) (DeFrate et al, 2007;Varadarajan et al, 2010), although other studies have assumed these soft tissues to be single bulks (Bergamini et al, 2011;Gill and O'Connor, 1996;Jeong et al, 2010;Meister et al, 2000;Robinson et al, 2009;Sakane et al, 1999;Sheehan, 2007;Taylor et al, 2011). The presence of isometric fibres throughout the flexion arc when this is achieved in virtually unloaded, i.e., passive conditions, was also investigated Jeong et al, 2010;Grood et al, 1989;Zavras et al, 2001).…”