Mrs L is a 49 year old lady who initially presented to Dr Touzell five weeks following an ankle sprain. She was initially treated in a CAM boot by her allied health practitioner, but after coming out of the boot her ankle was quite sore and she was struggling to mobilise without pain. She also had significant ankle swelling. She reported a history of difficulty walking uphill as well as ascending stairs, a symptom of syndesmosis pathology, but interestingly no instability.
On initial examination, Mrs L had a swollen left ankle. She struggled to perform a single leg heel raise because of pain. She was tender to palpation at the level of this distal tibiofibular joint and the pain was exacerbated by dorsiflexion and external rotation. Her distal fibula was non-tender to palpation. She had a stiff ankle to dorsiflexion, but her subtalar joint was mobile and non tender. Her peroneal tendons and achilles tendon were non tender.
An MRI scan was ordered which demonstrated a high-grade syndesmosis injury and small posterior malleolus fracture (which is pathognomonic for syndesmosis injury):
A long discussion was had with Mrs L. High grade syndesmosis injuries are normally associated with ongoing pain and instability after an innocuous ankle sprain, and are often treated with surgical syndesmosis stabilisation. However, Mrs L was very keen to avoid any kind of surgical intervention, and was understanding that if she was still symptomatic after a period of strengthening and rehabilitation she may require syndesmosis stabilisation surgery in the future.
Mrs L was commenced on a functional rehabilitation program under the supervision of her physiotherapist. This involved an initial six week period of weight bearing in the boot, combined with swelling management, gentle range of motion and hip and knee strengthening and range of motion exercises. The subactue phase involved coming out of the boot and commencing weight bearing, and starting bilateral calf raises, stability work and progressing her lower limb strengthening program. Importantly, there was no forced dorsiflexion of the ankle during this time. Six weeks later, Mrs L then progressed to single leg calf raises and stability exercises, and had returned to her regular walking regime.
Five months following her injury, she is completely pain free and has returned to her regular activities (and is very glad she avoided surgery!). Her affected ankle was moderately stiff with a reduced knee-to-wall range in comparison to her contralateral side, but this was slowly improving with her rehabilitation and home exercise program.
Discussion
This case highlights the ability for high grade syndesmosis injuries to be treated non-operatively. Mrs L was a relatively low-demand patient who (in her words!) was 'inherently lazy' but did enjoy walking and was a busy working parent at the time of the injury. She was prepared to undergo surgical stabilisation if non-operative treatment was not successful. She also had an experienced physiotherapist who avoided forced dorsiflexion following her injury and provided a comprehensive management program. In a higher demand, athletic patient early syndesmosis stabilisation may still be appropriate, but this case highlights that non-operative treatment should be discussed. Syndesmosis injuries should be suspected if an ankle sprain is not improving. Low to high grade injuries are not usually detected on routine x-ray or ultrasound, unless there is a fracture of the posterior malleolus or significant widening of the syndesmosis suggesting a severe injury. The syndesmosis can be assessed clinically via palpation of the distal tibial-fibula joint, as well as performing syndesmosis stress testing such as forced dorsiflexion combined with external rotation of the ankle. An MRI is the imaging modality of choice if syndesmosis injury is suspected and involvement of an orthopaedic surgeon to discuss operative treatment is appropriate.
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