Anterior lateral ankle ligament damage and anterior talocrural-joint laxity: an overview of the in vitro reports in literature

Objective. To provide a clear overview of the literature on the relationshi p between increased lateral ankle ligament damage and anterior talocrural-j oint laxity. Design. A systematic review of the literature. Background. Diagnostic methods for inversion injuries of the ankle have rem ained controversial throughout the years. An instrumented test for anterior talocrural-joint laxity could be a diagnostic toot for evaluation of anter ior lateral ankle ligament function. Methods. An advanced electronic database search using MEDLINE and EMBASE wa s performed to find studies describing the correlation between lateral ankl e ligament damage and talocrural-joint laxity. Two reviewers assessed the m ethodological quality for each study and agreement was noted. Two reviewers extracted all relevant data with respect to methodology, motion constraint s and laxity measurement. Results. The quality assessment resulted in 5 studies being scored as high quality and 5 as low quality. Different test devices were used to apply the load and measure the displacement. All in vitro tests applied a load to th e calcaneus and subsequently measured the translation of the talus and/or c alcaneus relative to the tibial dome. Rotation in the transversal and front al plane was restricted in 8 tests. After analysis of the results presented by nine different studies, the mean value of anterior talocrural-joint lax ity with intact ligaments is 4.2 mm. After sectioning of the anterior talof ibular ligament, the mean anterior laxity value is 6.5 mm. The mean anterio r laxity value after sectioning of the calcaneofibular ligament increases t o 8.4 mm. The mean anterior laxity value with the foot in dorsal flexion (3 .1 mm) is less than the mean value with the foot in neutral position (4.5 m m) or in plantar flexion (4.7 mm). The applied load and the anterior laxity values between the different studies vary greatly. Conclusions. Each ligament section results in significantly increased taloc rural-joint laxity. Talocrural-joint laxity can be used as a measure for da mage to the anterior talofibular ligament and/or the calcaneofibular ligame nt. From this review, it is neither possible to give universal recommendati ons about the optimal flexion angle for testing talocrural-joint laxity as a measure for lateral ankle ligament function, nor to recommend the ideal l oad for performing the test.