The undefined anatomical variations of the deltoid ligament bundles: a cadaveric study

Abstract

Introduction: Recently, Cromeens proposed a new interpretation of the deltoid ligament (DL) using its attachment sites to define individual components. The aim of this cadaveric study was to evaluate the reproducibility of this new classification and investigate anatomical variations of the ligament to contribute to reaching an evidencebased consensus regarding its ligamentous constituent bands, their origins and insertions. Methods: The classification was applied to study only four components of the DL: the tibiocalcaneonavicular (TCN), the superficial posterior tibiotalar (sPTT), the deep anterior tibiotalar (dATT) and the deep posterior tibiotalar (dPTT) ligaments. Fifteen fresh frozen ankles were dissected and the deltoid ligament components de-fined by their attachment sites and measured on the three axes.Results: The TCN, sPTT and dPTT ligaments were identified in all of the specimens. The TCN was the widest and longest ligament with variable thickness. The sPTT ligament was the second thicker and longer. The dATT ligament, the smaller and thinner, was not identified in 3 specimens. The dPTT ligament was the second wider, which in 3 cadavers presented an accessory bundle, the deep intermedial tibiotalar ligament (dITT ligament). Conclusions: Cromeens's attachment-based classification was proved to be simple, rational and reproducible in allowing the methodological description of the different bands of the DL. Our findings showed that the dITT ligament must be considered a secondary bundle of the dPTT ligament, which was not always identified in all specimens. Level of evidence: IV. Clinical relevanceThe anatomical data regarding the deltoid ligament bands and their variations described in this study should promote correct management of ankle sprains in cases of deltoid ligament injury or instability, often trivialized, addressing the proper treatment: conservative or operative.

Defining the Components of the Deltoid Ligament (DL): A Cadaveric Study

“…These findings partially align with descriptions in the literature where six different components of the DL were determined, but four components belonged to the superficial layer and two for the deep layer [9,11]. By contrast, eight different bands of the DL have been also described: the tibiocalcaneal ligament, the anterior talotibial ligament, the TNL, the superficial posterior talotibial ligament, the deep posterior talotibial ligament, fibers to spring ligament (plantar calcaneonavicular), and a deep band to the tibiocalcaneal [9,12,13]. In 1979, Pankovich and Shivaram, after dissection of 16 cadaveric ankles, described three bands for the superficial layer (superficial talotibial, calcaneotibial, and naviculotibial ligaments) and two for the deep layer (deep posterior talotibial and deep anterior talotibial ligaments) [14,15].…”

Ultrasound Examination of the Ligament Complex Within the Medial Aspect of the Ankle and Foot

“…The various bands within the DL (TNL, TSL, TCL, sPTL, and anterior superficial tibiotalar ligament [ASTL]) 3,10 emerge from the periosteum of the medial malleolus, divide, and then attached the navicular, the talus, the SCL, the calcaneus (sustentaculum tali), and the posterior talus 11 after crossing 2 joints, except the ASTL that the fascicles attach to the navicular, those of the ankle and the subtalar 8–10,12 (Figure 1A). The superficial components maintain the alignment of the talus and the medial malleolus, 13 providing resistance against the valgus and external rotation of the talus 3 by limiting hindfoot eversion 2,7 . In acute ankle injuries, the absence of any of these components might compromise joint stability 14 …”

“…The deep lamina is composed of 2 short, strong ligaments that span only the ankle joint 2,3,8,10,12 . The dATL and dPTL ligaments emerge from the deep margin of the medial malleolus and extend to enter the medial fovea of the talus 18 .…”

“…The superficial components maintain the alignment of the talus and the medial malleolus, 13 providing resistance against the valgus and external rotation of the talus 3 by limiting hindfoot eversion. 2 , 7 In acute ankle injuries, the absence of any of these components might compromise joint stability. 14 …”

“…The medial collateral ligament complex (MCLC) or deltoid ligament (DL) forms a strong composite structure that stabilizes the tibiotalar and subtalar joints and helps prevent excessive eversion of the hindfoot, controlling the valgus, the external rotation, and the anterior translation of the talus. 1 , 2 , 3 , 4 , 5 , 6 Although DL injuries account for only 5 to 10% of those affecting the ankle ligaments of the active population, 2 they are related to processes such as hyperpronation, 1 damage to the articular cartilage of the talus, 6 , 7 and the chronic mechanical instability associated with DL laxity after injury. 6 …”