When examining patients with ankle sprains, physicians should look harder for different pathologies and possible fractures
Ankle injuries are often self-diagnosed by individuals as mere sprains. Physicians, too, sometimes make the same diagnosis.
However, suppose these injuries are not treated accordingly. In that case, the condition might lead to other abnormalities, said Dr Jonas Fernandez, Orthopaedic Specialist at Putrajaya Hospital.
He shared this at a Continuous Medical Education (CME) series on May 28, 2021.
Dr Fernandez said he chose the topic of ankle injuries for his sharing session due to this common misdiagnosis.
“There are many times where patients seemed to be diagnosed with ankle sprains when they can actually mean a lot of other things.”
He focused on the ankle’s lateral part, which consists of the fibula, talus, calcaneum, ligaments, and peroneal tendons. He said that the most common mechanisms for lateral ankle injuries were inversion and supination.
When is an ankle X-ray necessary?
He highlighted the Ottawa Ankle Rules, which were the guidelines for physicians to rule out the possibilities of bone fractures for patients with ankle pains. The rules were not just limited to lateral ankle injuries but all ankle injuries in general.
“If you (physicians) feel tenderness over the lateral malleolus, medial malleolus, navicular and the base of the metatarsal or if the patients are unable to bear weight, then it’s justified to do an ankle X-ray.”
Dr Fernandez noted that the Ottawa Ankle Rules could reduce the number of unnecessary radiographs by 30-40 per cent. The Rules had an almost 100 per cent accuracy rate.
The most common reason for lateral ankle pain
The orthopaedic surgeon also stated that although it could mean other things, the most common cause of lateral ankle tenderness was still ankle sprains.
He said: “If we’re talking about ankle sprains, we’re talking about the complication of the anterior talofibular ligament (ATFL), calcaneo-fibular ligament (CFL) or the syndesmotic joints.
“For ATFL injuries, you can start by carrying out the anterior drawer test, and for CFL injuries, you can try the talar tilt test. These tests have almost 100 per cent sensitivity.
“As for syndesmotic injuries, they can be diagnosed by using the squeeze test and external rotation test,” he explained.
He stated that the treatment for these injuries would always start with conservative treatment. This was able to resolve patients’ problems most of the time. However, if conventional treatment fails, surgery might need to be carried out. He also emphasised that if a patient was not appropriately treated, it could lead to something chronic like deformity of the ankle.
The snowboarder’s fracture
Dr Fernandez shared that there was something called ‘snowboarder’s fracture’, often misdiagnosed as a sprain. The ‘snowboarder’s fracture’ is a fracture of the lateral process of the talar. However, compared to an ankle sprain, the pain of this fracture will be slightly more posterior to the ATFL and will be just to the tip of the fibula.
“If you ignore the lateral process of the talus, it’s very easy to miss such fractures. Even if you do not see them on an X-ray, there’s a role for a CT scan or MRI to detect these fractures.
“Missing such fractures can lead to deformities or chronic problems like deformity of the foot and ankle,” he revealed.
He further explained that three types of this fracture should be treated accordingly according to the Hawkins classification.
Anterior calcaneal process fracture
Dr Fernandez explained about another bone-related ankle injury, an anterior calcaneal process fracture. He said that, like any other ankle injury, if the physicians did not look out for fractures, the injuries would be treated as sprains because the injuries’ mechanism was very similar to ankle sprains.
He explained: “As for this anterior process of the calcaneum, the tenderness is a bit more anterior compared to where the ankle sprain tenderness would be.
“Again, there’s a role for conservative treatment, but where necessary, we can try to treat it by doing surgery.”
Fifth metatarsal base fracture
Dr Fernandez said that the fifth metatarsal base fracture was not missed as much as the other two fractures. This was due to the Ottawa guidelines, which instructed physicians to palpate the fifth metatarsal base. The fracture was also classified into three zones, namely Zone I (Avulsion), Zone II (Jones) and Zone III (Dancer).
He said that fractures in Zone I and Zone II would appear clearly in an X-ray, but it would be hard to find the ones in Zone III. He further explained that the problem with Zone I and Zone II fractures was their attachment to the tendons.
“This causes fragments to be pulled away and makes it difficult to heal. It is also due to the nature of blood supply to that area.”
He shared that most injuries in Zone III were stress fractures. They can sometimes lead to displacement if treated conservatively. However, there is a need for surgery for Zone I and Zone II, which, if not appropriately treated, tend to go into non-union fractures.
Osteochondral lesions of the talus
Another fracture, he said, had to do with the talus. For this type of fracture, he said the problem resided in the insufficient blood supply to the talus’s different zones, making it prone to osteonecrosis (death of bone cells). Patients with this kind of fracture would suffer from pain or other symptoms of clicking and catching.
“The pain would be more anterior compared to ankle sprains. Some can be treated conservatively. Others may require surgery which include using the scaffold to rebuild it or by using cell-based and biologic agents,” he said.
Peroneal tendon injuries
Dr Fernandez said these injuries can be something acute like an inversion or could also refer to the underlying problems of tendons that might rupture later on peroneal tendon injuries.
“In this case, the tenderness will be more over the posterior part of the distal fibula. Clinically, you might be able to feel the peroneal tendon subluxated anteriorly,” he explained.
He said that patients might experience the dislocation or subluxation of the peroneal tendon due to the pathology of the retinaculum itself, and not so much to do with the tendon.
“This is because the retinaculum was supposed to hold the tendon in place. So, if there is something wrong with it, the tendon could snap out of place.
“You could try conservative treatment in cases with subluxation or dislocation of tendons. However, if after several times the problem is not resolved, you’ll end up with surgery as well.”
Dr Fernandez concluded by emphasising the need for physicians to properly examine their patients. “The next time you see a patient with ankle pain, you shouldn’t just think of it like an ankle sprain. Look harder for different pathologies and all possible fractures.
“Ask the patient expressly to point out where the pain is. The most important thing, and I cannot stress this enough, is clinical judgment.
“If you suspect that there is a possibility of something more than just a sprain, order an X-ray to look for fractures. Remember, the eye doesn’t see what the mind doesn’t know.” — The Health