Monday, June 29, 2020

Ankle Fractures


An ankle fracture needs anatomic reduction & absolute stability. Anatomic reduction and stable fixation of the posterior malleolus is very important. In a trimalleolar ankle fracture with syndesmotic instability, anatomic reduction and fixation of the posterior malleolus provides greater syndesmotic stability, and it lessens the need for syndesmotic screw fixation. It restores the stability better than placing syndesmotic screws. Failure of fixation or conservative treatment that gives us undesirable result of ankle fracture treatment. You see the patient with hardware failure, syndesmotic problems, and malalignment of the ankle. Some of these patients are treated surgically and did not do well. Some of these patients are treated conservatively and did not do well. Some of these patients may have redisplacedment of the syndesmosis after syndesmotic fixation. Some of these patients may have malreduction of the syndesmosis that may or may not be obvious. Some of the patients may have shortening of the fibula. Some of the patients may have conservative treatment and the ankle is not well aligned, so you will need to do revision surgery. Ankle fracture malalignment due to failure of fixation. The presentation is that of an older fracture that healed improperly, or it was fixed, and the fixation failed, so you need to revise the treatment. The first thing that you want to do is to look at the ankle and see if you have arthritis. If you have some arthritis and the patient is young, then you can revise the ankle treatment. You want to make sure that you do not have a lot of arthritis before you do this big surgery. The question is, are we going to revise the syndesmosis alone, because one way or the other, the syndesmosis is malaligned. If the Shenton’s line is interrupted or if the dime sign is interrupted, then the fibula is short. If the patient has peripheral neuropathy or Charcot arthropathy, there will be more complications. If you are going to handle a diabetic patient, you will need to do surgery and you will need to put more hardware and prolong the area of non-weight bearing (instead of 6 weeks, it will be 3 months). We do external rotation stress view x-rays before surgery to look at the medial clear space, and you will check the integrity of the deltoid ligament. If you do stress view x-rays before surgery, it is done to see if the deltoid ligament is injured or not in an ankle fracture when you are not sure if the deltoid ligament is injured. If deltoid ligament turns out to be injured, then the patient will need surgery, and if it is not injured, then the patient will not need surgery. When you do the stress view, and if the medial clear space does not widen, then the fracture is external rotation Type II that is treated conservatively. When you do the stress view, and the medial clear space is widen, then the deltoid ligament is ruptured and surgery is needed (external rotation Type IV). Before surgery, you will check the medial clear space to check the integrity of the deltoid ligament. During surgery, when you check the integrity of the syndesmosis, you check the tibiofibular clear space. The tibiofibular clear space will be greater than 5mm with syndesmotic injury. To perform the cotton test, pull on the fibula with a bone hook and assess the integrity of the syndesmosis. During surgery, when you check the integrity of the syndesmosis, you can also check the medial clear space in addition to the tibiofibular clear space. If it is a pilon fracture and the patient starts weight-bearing now, then the patient can start driving 6 weeks from now. For the ankle fracture, return to driving is 9 weeks from the day of surgery. The type of fixations, type of screws, and how many screws used, and if you remove the screws or not all are controversial points. What is not controversial is that the syndesmotic reduction of the must be anatomic. You must restore adequate length, rotation, and alignment of the fibula. That will help anatomic alignment of the syndesmosis. Watch for reduction of the syndesmosis, because there is a lot of malalignment. If you are not sure, direct inspection and reduction of the syndesmosis can be helpful. Failure of the syndesmotic fixation can occur in over-weight patients, and it can also occur from surgical errors that may not be recognized during surgery. Supination-adduction mechanism of injury is characterized by vertical medial malleolus fracture associated with injury to talus and tibial plafond, movement of the talus medially, and impaction on anteromedial aspect of the ankle. Supination-adduction injuries are treated by screws parallel to the ankle joint or anti-gliding plate. In pronation injuries, the fibula is comminuted, usually at or above the syndesmosis. In supination-external rotation injury, the fracture goes anterior to posterior direction. This is the direction of the fracture in supination-external rotation. You see the fibular fracture in the lateral view, and you are not going to see the fracture well in the AP view. If you use lateral plate, it will decrease the peroneal tendon irritation, but the patient may feel the plate, and the screws may violate the joint. If you use posterior plate on the fibula, it is more stable and biomechanically better. It will cause more irritation of the peroneal tendons, especially if the plate is placed low and the screw heads are prominent.