Changes in the flexibility characteristics of the ankle complex due to damage to the lateral collateral ligaments: An in vitro and in vivo study

Abstract

This study was part of a long-term effort to develop a reliable diagnostic procedure for ankle ligament injuries. Earlier efforts led to the development and validation of a six-degrees-of-freedom instrumented linkage capable of measuring the flexibility characteristics of the ankle complex in vitro and in vivo. The major goal of the present study was to determine if these flexibility measurements are sufficiently sensitive to detect the presence of damage to the lateral collateral ligaments of the ankle joint both in vitro and in vivo. The in vitro testing was conducted on the legs from six fresh cadavers before and after serial sectioning of the anterior talofibular ligament and the calcaneofibular ligament. The flexibility in inversion-eversion, anterior drawer, and internal-external rotation was measured before and after resection of the ligaments. The in vivo testing was conducted on five patients with unilateral injuries to the ankle ligament. The flexibility evaluation used for in vitro specimens was also performed on both the injured and the intact ankles. For the in vitro testing, the data analysis was based on comparison of flexibility values before and after resection of the ligaments, whereas the data analysis for the in vivo testing was based on comparison of the flexibility of the injured joint with that of the intact contralateral joint. The results of the in vitro study indicated that both an isolated rupture of the anterior talofibular ligament and combined damage of the anterior talofibular and calcaneofibular ligaments produce statistically significant changes in flexibility. Furthermore, the most sensitive parameters to the presence of ligament injuries were found to be early flexibility in anterior drawer, early flexibility in inversion, and the amount of coupling between internal rotation and inversion. These parameters provided a basis for differentiating between an isolated injury to the anterior talofibular ligament and a combined anterior talofibular and calcaneofibular ligament injury. For an isolated anterior talofibular ligament injury, a significant increase in flexibility in anterior drawer was present, whereas the increase in inversion flexibility or in the amount of coupling was insignificant. However, the increases in inversion flexibility and the amount of coupling became significant when both ligaments were involved. The results of the in vivo study indicated that significant changes in flexibility can be detected in patients with lateral ankle injuries. Finally, both the in vitro and in vivo results suggest that development of a reliable diagnostic test for ankle ligament injury based on changes in passive flexibility may be possible.

Analysis of ankle−hindfoot stability in patients with ankle instability and normals

“…We found variability in absolute values of inversion or internal rotation measured between patients. It is well recognised that there is wide variation among individuals in stress tests [6,12,13,23], which our testing confirmed. This observation in preliminary testing led to refinements in how the foot was secured to the footplate, standardising a neutral position prior to testing, and the repeatability study that was conducted.…”

Joint Stability Characteristics of the Ankle Complex After Lateral Ligamentous Injury, Part I: A Laboratory Comparison Using Arthrometric Measurement

“…10 The objective of testing after ankle-ligament sectioning was to assess and compare the passive mechanical stability characteristics of the ankle complex between the intact and ligament-deficient ankles. Numerous investigators 2,5,8,[10][11][12]15,18 have reported increased in vitro ankle-complex instability after isolated and sequential sectioning of the ATFL þ CFL when loaded in AP drawer and I-E. Fewer researchers 2,15,25 have reported the effects of ligament sectioning on stiffness characteristics of the ankle complex.…”

“…9,10 Increases in ankle-complex motion with isolated and combined sectioning of the ATFL and CFL have been reported extensively. 2,8,[10][11][12] General consensus in the literature is that measuring the relationship between ligament damage and joint laxity by simulating ligamentous injury in the cadaver specimen improves our understanding of joint motion and the effect ligament damage has on producing instability in the ankle-subtalar complex. Thus, objective documentation that describes change in the passive mechanical properties of the ankle complex with lateral ligament injury could be important in the differential diagnosis of these injuries.…”

A Composite Athletic Tape With Hyperelastic Material Properties Improves and Maintains Ankle Support During Exercise

“…33 The potential of this device as an effective diagnostic tool for ankle ligament injuries has also been demonstrated by characterizing the changes produced in the load-displacement properties of the ankle resulting from ligament injuries. 18,19 Athletic tape with hyperelastic properties that are maintained after exercise and which decreases ankle/tape flexibility throughout a prolonged athletic activity may provide a significant improvement over the currently available conventional athletic tapes. The goal of this study was to introduce a hyperelastic tape and to compare its performance to that of conventional athletic tape.…”

“…Such hyperelastic properties are exhibited naturally by biological structures, such as ligaments and tendons, 12,30,37 as well as by anatomical joints. 9,18 However, conventional athletic tapes or ankle braces do not possess such hyperelastic properties and substantially interfere with joint motion in its functional range, thus reducing comfort and athletic performance. 7,22,29 Furthermore, several previous studies have shown that conventional athletic tape loses its effectiveness (passive support) during exercise, with some studies reporting a reduction in support of up to 50% during the first 10 to 30 minutes.…”