Syndesmosis ( membrana interossea ) refers to the connective tissue membrane, which connects the fibula and the tibia and is therefore required for the stabilization of the ankle joint. In the lower portion close to the jump joint, the syndesmosis guarantees this stability in conjunction with the outer band and the inner bands.
In case of torsion or compression injuries of the ankle, the syndesmosis (syndesmotic tear) or a part of it can rupture. Above all, an excessively strong external rotation of the talus ( talus ) carries the risk of a syndesmotic injury.
This can also occur if no bony structures are affected, so that the exclusion of a fracture in the ankle joint is not sufficient to rule out a syndesmotic tear.
Syndesmosis rupture is a classic sports injury and is more common in sports where accidents with severe ankle rotation are likely. These include, for example, skiing to the same extent as exercise-intensive ball sports.
A syndesmotic tear sometimes causes severe pain in the ankle, which often makes it impossible to fully load the affected leg. In addition, the joint swells in most cases strongly and has a pressure painfulness as well as a painful external rotation.
Since the radiographic exclusion of a bone injury does not preclude injury to the ligaments, the diagnosis must be made primarily clinically.
The local tenderness and the behavior in the stress test in external rotation of the ankle or compression of the calf and hamstring (syndesmotic compression test) can give an indication of the extent of the injury.
Conventional X-rays and magnetic resonance imaging (MRI) are often helpful and can support the diagnosis. Magnetic resonance imaging may also be useful in planning any necessary surgery.
If a syndesmotic tear is suspected, other injuries such as an external ligament tear, ankle fracture, and fractures of the tibia or fibula may also be considered and must be ruled out.
In the acute phase, the affected extremity must be stored and cooled. In addition, the use of anti-inflammatory drugs (ibupropene, paracetamol, aspirin) for pain therapy makes sense.
The primary goal of long-term therapy is to restore the stability of the ankle and thus the ability to exercise and exercise. Here, a distinction must be made between the strain or the incomplete rupture of the syndesmosis and the complete rupture. In case of an incomplete rupture, the conservative restoration with immobilization can be done in an orthosis. A complete rupture of the syndesmosis, combined with severe pain and instability of the upper ankle, can lengthen the conservative regimen.
The affected limb is immobilized with a lower leg cast or a removable brace for about six to ten weeks.
The exercise can be carried out in the absence of pressure pain and pain-free possible external rotation of the calcaneus and should be accompanied by a physiotherapist as soon as full resilience exists.
In case of a gross malalignment of the heel bone, an operative therapy may be necessary. Depending on the procedure, the joint is stabilized with a jump-joint-spanning set screw and the ligaments are reconstructed, if necessary, with resorbable sutures, or a minimally invasive procedure is performed using permanent implants remaining in the body. In the first case, metal removal under short-term anesthesia becomes necessary at a later point in time, even before the beginning of the full load.
Postoperatively, partial support of the injured joint is possible, supported by forearm crutches.
After one to two weeks, sedentary activities such as work at the desk and office work can be resumed. When moving around the workplace, the consistent use of walking aids must be taken into account.
Standing activities must first be avoided. A possible use in the workplace depends on the clinic of the injured limb. Work involving more physical activity may not be resumed until full exercise is possible and adequate physiotherapy has been provided.
After six weeks, the careful, therapeutic training can be resumed. Care must be taken here that the clinic of the joint makes the therapy possible. Swelling and pain as described above should be largely reduced.
With consistent and professionally carried out reloading is to expect a production of athletic performance, as it existed before the injury, after ten to twelve weeks.
In the treatment of the often young injured, care must be taken to be cautious and, above all, adapted to avoid worsening the picture of injury with possible late damage.