Learning objectives
Review the anatomy of the lateral ankle
Discuss the pathophysiology and clinical presentation of extraarticular lateral impingement of the hindfoot
Identify imaging findings associated with extraarticular lateral impingement of the hindfoot
Understand the clinical importance of extraarticular lateral impingement of the hindfoot
Background
Introduction
Pain localized to the lateral ankle region is often attributed to subtalar joint degeneration or sinus tarsi syndrome.
However,
extraarticular soft-tissue and osseous impingement is an unrecognized entity that can cause lateral ankle pain.
The impingement occurs lateral to the ankle joint as a result of flatfoot deformity with resulting talocalcaneal subluxation and valgus hindfoot malalignment.
Lateral hindfoot impingement is often seen in patients with severe hindfoot deformity secondary to congenital or acquired flatfoot deformity.
Other causes of lateral hindfoot impingement include tarsal coalitions,...
Imaging findings OR Procedure Details
Imaging Findings
In patients with lateral hindfoot impingement plain radiographs may reveal bony contact between the lateral calcaneus and talus as well as sclerosis or cystic changes (figure 2).
Based on findings on plain radiographs,
in the context of clinical history and physical examination findings,
a CT scan or MRI can be orderedtohelp narrow the differential for etiology of symptoms.
CT scanscan better identify cystic changes and sclerosis iwhen compared to plain radiographs.
In patients with calcaneal malunion,
CT scan reconstructed images are useful for...
Conclusion
Flatfoot deformity with secondary hindfoot valgus can lead to painful extraarticular lateral hindfoot impingement,
which often needs surgery to stabilize and realign the foot.
The recognition of imaging findings associated with this entity is paramount in order to make an early diagnosis and to choose the appropriate surgical procedure,
while allowing to exclude other causes of lateral ankle pain,
therefore improving surgical outcomes.
References
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Extra-articular lateral hindfoot impingement with posterior tibial tendon tear: MRI correlation.
Donovan A,
Rosenberg ZS.
American Journal of Radiology,
September 2009,
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193: 672-678.
MRI of Ankle and Lateral Hindfoot Impingement Syndromes.
Donovan A,
Rosenberg ZS.
American Journal of Radiology,
September 2010,
Vol.
195: 595-604.
Subfibular impingement: current concepts,
imaging findings and management strategies.Kaplan,
JRM,
Aiyer A,...