[Is surgical treatment of deltoid ligament rupture necessary in ankle fractures?]

Fractures of the lateral malleolus associated with rupture of the deltoid ligament are severe fractures types. There is still discussion about wether the ruptured deltoid ligament should be sutured or not. To elucidate further the need for surgical repair of this structure a comparative and retrospective review was conducted at a mean follow-up of 4 years and 8 months.

Twenty nine men and 15 women were included with a mean age of 34 years. Patients were subdivided into two groups according to the attitude regarding the ligament. In the first group (n = 18), an operative repair of the ligament was made and in the second group (n = 17) we leaved it unrepaired. Nine patients were evaluated separately because of an associated osteochondral fracture (n = 7) or a worse reduction of the fibula (n = 2). Subjective and objective clinical assessment were evaluated according to a modified Cedell classification. Roentgenograms including A.P, lateral, mortise view and a external rotation stress view described by Kleiger were obtained in all patients.

Subjective and objective analysis showed no significant difference between the two groups, likewise no differences were observed for post operative complications rate. Medial instability was observed in four cases (2 in group 1 and 2 in group II). Roentgenographicaly, more ossifications of the deltoid ligament were founded in group II (p = 0.013), and only one degenerative osteoarthritis of the ankle was seen in group II. Clinical results in the group of patients with osteochondral fracture were statistically worse than in the two previous groups (p = 0.001), with frequent progression to osteoarthritis in four cases.

In our experience it is impossible to advise surgical repair of the deltoid ligament in accordance to the type of lateral malleolar fracture like other authors have suggested. The existence of a significant widening of the medial space greater than 3 mm was nearly correlated with a deltoid ligament disruption, of the 23 patients treated with a medial approach, the ligament was ruptured in 22 cases. In this study, we may conclude than an untreated rupture of the deltoid ligament does not lead to instability. The advantages of the deltoid repair may be obtained if the fixation of the lateral malleolus allows a perfect congruency of the mortise. The most predictive radiographic factors for a poor outcome were a persistent widening of the medial joint greater than 3 mm, an associated osteochondral fracture and a poor reduction of the lateral malleolus which results in degenerative arthritis of the ankle at long term follow-up.

Repair of the deltoid ligament is unnecessary if the internal fixation of the fibula achieves an anatomical reconstitution of the mortise. Exploration of the medial side is indicated only with a medial incongruency greater than 3 mm on intra operative roentgenograms.