The deltoid ligament, which is divided into superficial and deep, comprises the rest of the MMOLC.
Also important to consider is the close approximation of the posterior tibial and flexor hallucis tendons to the deltoid ligament as their tendon sheaths are essentially contiguous with the insertions of the deltoid ligament complex.
In the anatomical arm of the study, cadaver ankles underwent stress testing after an isolated deltoid ligament division, isolated medial malleolus fracture, isolated division of the fibular collateral ligaments, and a short oblique distal fibula osteotomy with all ligaments intact.
Forty-six ankles, therefore, underwent operative fixation of the medial malleolus or suture repair of the deltoid ligament without fibular fixation in any of the fractures.
Criteria for inadequate reduction were set as follows: lateral malleolar displacement greater than 2 mm on the AP or lateral, medial malleolar displacement of greater than 1mm on the AP only, deltoid ligament disruption with more than 3 mm medial clear space, syndesmosis injury with tibia-fibula clear space greater than 5 mm or tibia-fibula overlap of less than 10 mm (both on the AP), or a tibia-fibula overlap of less than 1 mm on the mortise view.
Their conclusions stated that bimalleolar ORIF provided far superior results than closed treatment of ankle fractures, and that patients with a medial malleolar fracture (as opposed to just a deltoid ligament rupture) faired significantly worse when treated by closed reduction.