Medial ankle ligament

Top Contributors - Saumya Srivastava, Mariam Hashem, Venugopal Pawar, Priyanka Chugh, Nicolas D'Hondt and George Prudden

Introduction

The Deltoid ligament (or the medial ligament of talocrural joint) is a strong, flat and triangular band. It is attached above to the apex and anterior and posterior borders of the medial malleolus. The Deltoid ligament is composed of superficial and deep components.

The superficial components:

• The tibiocalcaneal ligament,
• The tibionavicular ligament
• The posterior superficial tibiotalar ligament
• The tibiospring ligament

The deep components:

• The anterior tibiotalar ligament (ATTL)
• The posterior deep tibiotalar ligament (PDTL)

Clinically Relevant Anatomy

The deltoid ligament attaches the medial malleolus to multiple tarsal bones. Unlike the superficial layer of this ligament, the deep layer is intraarticular and is covered by synovium. Anatomically, in general, the superficial components arise from the anterior colliculus of the medial malleolus, and the deep components arise from the intercollicular groove (malleolar groove) and the posterior colliculus of the medial malleolus.

The superficial deltoid originates from the anterior & inferior aspects of medial malleolus fanning out & sending 3 bands to navicular and along plantar calcaneonavicular (spring) ligament, to sustenaculum tali of calcaneus and to medial tubercle. It is also partially covered by tendon sheaths & crural fascia. It primarily resists eversion of hindfoot; Tibionavicular portion suspends spring lig & prevents inward displacement of head of talus, while tibiocalcaneal portion prevents valgus displacement.

The deep deltoid originates on posterior border of anterior colliculus, intercollicular groove, & posterior colliculus. It is oriented transversely & inserts into the entire nonarticular surface of medial talus. Deep deltoid extends the function of the medial malleolus, prevents lateral displacement of talus & prevents external rotation of the talus (this is mostly significant in plantar flexion, when deep deltoid tends to pull talus into internal rotation).

Medial ankle stability is provided by the strong deltoid ligament, the anterior tibiofibular ligament and the bony mortise. Because of the bony articulation between the medial malleolus and the talus, medial ankle sprains are less common than lateral sprains. In medial ankle sprains, the mechanism of injury is excessive eversion and dorsiflexion.

Isolated deltoid ligament injuries are extremely rare and usually occur in combination with fractures of the lateral malleolus. These are treated by recognizing the injury complex and stabilizing the lateral side, being sure that the mortise is reduced.

Physical Examination

Eversion Test-
In neutral evaluates superficial deltoid ligament complex.
External rotation stress test evaluates syndesmotic ligaments and additionally - the deep deltoid ligament;

Radiographic Diagnosis of Injury

Deloid is usually avulsed from tibial attachment, frequently w/ small flake of bone visible on x-rays;
- disruption of deltoid ligament can be dxed w/ relative confidence when medial clear space between talus & med malleolus is increased;
- lateral shift of talus, w/ incr medial joint space ( > 3 mm), but this may be apparent only on stress view or in postcasting films, after swelling has subsided;
- presence of medial tenderness & > 5 mm of space is seen then there is substantial injury of deltoid ligament;

Treatment of Deltoid Tear

- such injuries should be rxed as bimalleolar frx, w/ ORIF of lateral malleolus;
- routine exploration of medial side of ankle is not necessary unless there is evidence that portion of deltoid lig has entered joint & is blocking reduction of talus

Physical Therapy Management

To avoid ankle sprains, or ankle instabilities we have exercises to enforce or train the medial ligaments of theankle. Those ligaments are important to avoid an eversion of the ankle (eversion trauma’s). Otherwise we have exercises that are used after ankle sprains or ankle instability.

First and second degree sprains are typically managed with conservative treatment. This conservative treatment consists in de early stages of RICE (rest, ice, compress, elevate) and mobilization to prevent range of motion loss. When pain and inflammation are controlled, we can start with therapeutic exercises to increase the range of motion stability, strength proprioception and function.

For the third degree there has to be surgical treatment to resolve the structural damage. After this surgery, the ankle is immobilized. If there is pain or oedema after the immobilization, this has to be treated first before starting the conservative treatment, which is the same as for the first and second degree.

After two weeks when started physiotherapy, we can give strengthening exercises for the medial muscles and ligaments of the ankle. The first exercise, the subject had to sit on a chair or massage table with his leg extended. The physiotherapist held the leg in his one hand just below the knee. In his other hand he held the lateral side of theankle. The physiotherapist moved the foot to inversion, and gave some manual resistance. The subject had to perform an eversion, against this resistance. The physiotherapist held the resistance for 3 to 5 seconds. The exercise had to be repeated for 10 to 12 times. (level of evidence 2A)

This exercise can also be done without the resistance of a physiotherapist. The subject takes place on a chair. He puts an elastic tubing around his foot, and puts his other foot on the elastic tubing. He holds the elastic tubing in his contralateral hand. Then he has to perform the same exercise as with the therapist. He has to push his foot outward, with his footpad away from the midline of his body.

We can start exercises for proprioception after 5 weeks when started physiotherapy.
Exercise for training the proprioception, the double-leg right/left condition, the subjects had to sit on a chair, with their feet on a kinaesthetic ankle board. They had to keep their knees at a 90° angle, while maintaining contact with the top of the KAB with their respective extremities. Then they had to rotate the board to the left side and then back to the right (=clockwise and counter clockwise). The subjects had to keep the side of the board in the floor each time they moved the board to the left or the right. Each exercise had to be done 3x25 times. (level of evidence 2B)

The next exercise had to be done in stance. First they had to stand flat floor and then on a balance board. The subjects had to stand on one leg on the floor, first with their eyes open and thereafter with their eyes closed. Each exercise had to be done 3x15 times. After this exercise the subject had to stand with both feet on a balance board or wobble board. They had to make circular movements to train eversion, but also inversion, dorsiflexion and plantar flexion.

The next exercise was the same as the first one, but now the subject had to stand on the balance board. They were instructed to stand on one leg in the middle of the balance board, and then they had to maintain the stance on the balance board. First they had to do it with their eyes open, thereafter with their eyes closed. Each exercise was performed during 30 seconds. (level of evidence 2B)  

To make these exercises more difficult we could vary the surfaces, on the floor, a balance board, and an instable underground. Another way to increase the difficulty was to open or close the eyes while performing the exercises. The physiotherapist could also increase the exercise by giving light perturbations while the subject balanced on the balance board.