Anterior Ankle Impingement
Anterior ankle impingement is an umbrella term that refers to pain in the front of the ankle when dorsiflexing the foot, particularly in load bearing. The front of the ankle can be subdivided into three compartments, anteromedial, anterior, and anterolateral. Generally speaking, something is being pinched between the talus and tibia. Athletes are disproportionately affected more than the average population. Anterior ankle impingement can be treated conservatively, or with surgery (Berman et. al, 2017).
Anterolateral impingement can be caused by several structures and occurs in what is known as the anterolateral gutter (ALG). The ALG is the most common site of ankle impingement (Green & McCabe, 2018). This gutter is located just under the outside ankle. There are three ligaments (ATFL, AITFL, CFL) in the ALG and this form of impingement usually occurs after a ‘rolled ankle’ or inversion sprain. One or more of these ligaments thickens in response to injury along with the synovium of the joint capsule. The ligament and synovium can fuse into a fibroid mass in the ALG (Berman et. al, 2017). This mass is what is being pinched when your ankle is in dorsiflexion.
Some other causes of anterolateral impingement are bone spurs, small ganglia, and bone fragments. A less common cause of anterolateral impingement is from an accessory ligament called “Basset’s ligament”. It’s an anatomical variance and is just below the AITFL. Surgical excision of Bassett's ligament is considered safe and effective (Toye, 2014).
Anterior impingement occurs from repetitive microtrauma to the talus and tibia, anteriorly. The body responds to repetitive stimulus by laying down tissue (this is called Wolff’s law). This repeated stimulus can lead to an exostosis, or bone spur. The spur causes a Cam-type impingement. This can also cause an inflammatory response to the synovium of the capsule and lead to fibrous band formation. Bone spur formation alone is not necessarily a problem and many ballet dancers and soccer players that have bone spurs are asymptomatic (Berman et. al, 2017).
This is often followed by a plantar flexion/inversion injury. Initially, there is damage to the anterior tibiotalar ligament which then thickens. Bone spurs, synovitis, and fractures can contribute. Bone spurs can form along the talar neck or the medial malleolus (inside ankle) which can restrict range of motion (Berman et. al, 2017).
What can be done about it?
When the foot plantar flexes, the talus glides anteriorly. With sports that require repetitive and forceful plantarflexion, it is common to have irritation anteriorly, or in the front of the foot. If there is a restriction in the back of the ankle capsule, it can cause excessive translation of the talus. In other words, the bone rolls into and compresses the already irritated tissue into a spur. If the capsule is stretched properly, it may prevent pain anterior compression. There is commonly ankle instability associated with ankle impingement and strengthening the planes of motion that are weak will help prevent further exacerbation.
Cortisone injections may help reduce inflammation and pain symptoms. Ankle bracing may be recommended in athletes with chronic ankle sprains. Arch strengthening and/or orthotics to reduce vagus alignment (flat-footed) are recommended. Arthroscopic debridement has a high success rate in those that do not have arthritis. If surgery is elected, physical therapy will address reducing symptoms and prevent reoccurrence of ankle injury (Vaseenon & Amendola, 2012.
(n.d.). Ankle impingement syndromes: an imaging review. - NCBI. Retrieved June 7, 2019, from https://www.ncbi.nlm.nih.gov/pubmed/27885856
(2018, July 24). Key Insights On Ankle Impingement Syndrome In Athletes | Podiatry .... Retrieved June 7, 2019, from https://www.podiatrytoday.com/key-insights-ankle-impingement-syndrome-athletes
(2012, March 9). Update on anterior ankle impingement - NCBI. Retrieved June 11, 2019, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3535150/