[Injuries of the inferior tibiofibular syndesmosis]. / Verletzungen der unteren tibiofibularen Syndesmose.

The incidence of isolated distal tibiofibular syndesmotic ruptures in acute ankle sprains lies between 1% and 11%. These injuries are frequently overseen or misdiagnosed as anterolateral rotational instability of the ankle and often become apparent through protracted courses. Although the pathomechanics and extent of syndesmotic injuries have been systematically described by Lauge-Hansen and Weber, no generally accepted guidelines exist as to when these complex injuries are to be treated surgically to ensure sufficient and stable healing of the syndesmosis besides correct alignment of the distal fibula. So far, systematic follow-up regarding syndesmotic injuries in ankle fractures is missing, although it has long been recognized that tibiofibular diastasis secondary to chronic syndesmotic instability leads to external rotation of the talus. In combination with a valgus position of the talus, this instability leads to a decrease in the contact area which results in posttraumatic arthritic changes. This paper reviews the standard diagnostic and therapeutic procedures for acute syndesmotic ruptures in fracture dislocations of the ankle. Among the few corrective procedures advocated for chronic syndesmotic insufficiency are tibiofibular arthrodesis, synthetic ligament substitutes, and tenodesis with the peroneus brevis tendon. A sufficient reconstruction must restore the stability of the ankle mortise and alignment of the fibula in the tibiofibular incisura to ensure limitation of talar rotation. Therefore, a tenodesis was developed which substitutes the three important ligaments of the syndesmotic complex. The Casting procedure for chronic syndesmotic insufficiency was modified with reconstruction of the interosseous tibiofibular ligament in addition to the anterior and posterior tibiofibular ligaments. The resulting three-point fixation of the distal fibula appears more anatomically, physiologically, and biomechanically advantageous. The operative procedure is given in detail. Distal tibiofibular syndesmosis. Persistent instability of the distal syndesmosis. Ankle fractures. Syndesmotic screw.

[Injuries of the tibialis posterior tendon: diagnosis and therapy]. / Verletzungen der Sehne des M. tibialis posterior. Diagnostik und Therapie.

Complete traumatic rupture of the tibialis posterior tendon is absolutely rare. From the scarce case reports in the medical literature a extreme pronation-abduction or pronation-external rotation mechanism according to the Lauge-Hansen classification can be presumed, leading to a malleolar fracture because of forced pronation, external rotation and dorsiflexion of the foot. With primary suture the prognosis is favorable. Traumatic dislocations, mostly with luxatio pedis sub talo, are treated by atraumatic reduction and refixation of the retinaculum. Again, the prognosis is favorable. Incomplete traumatic rupture of the tibialis posterior tendon with development of posttraumatic pes plano valgus, according to case reports and our own experience result from severe pronation-external rotation-soft tissue injuries as well as with pronation-abduction or pronation-external rotation-type ankle fractures. In these cases no macroscopic rupture of the tendon is evident, however occult interstitial micro-ruptures can occur because of excessive stretching, which can be determined histologically. If conservative measures fail, a modified Evans osteotomy to lengthen the lateral foot column is indicated. Degenerative complete and incomplete ruptures of the tibialis posterior tendon are predominantly seen in women more than 42 years old. Staging of this entity can be achieved with clinical tests (muscular force, external rotation), ultrasound, weight-bearing x-rays, CT and MRT. According to the degree of decompensation of tendon function, treatment consists of augmentation, modified Evans procedure or triple arthrodesis of the hind-foot.