Associated injuries found in 64% of unstable ankles

Researchers discovered that 27% of soldiers had peroneal tears.

Surgeons routinely treat chronic ankle sprains, but in the process they may miss additional injuries that can lead to revision.

A retrospective naval study found that 64% of seamen treated for chronic lateral ankle instability also had associated conditions. Of the 160 patients who received reconstructive surgery, 20 required revisions. Hindfoot varus or peroneal injury often caused failure. “The conditions can potentiate, aggravate and participate in the ankle sprain morbidity,” said Joseph E. Strauss, MD, an orthopedist with the National Naval Medical Center. “Not addressing these conditions at the index surgery can often result in continued pain after ligament reconstruction.”

Researchers reviewed lateral ligament operations performed between October 1996 and March 2002, Strauss said during his presentation at the American Academy of Orthopaedic Surgeons 72nd Annual Meeting. Investigators discovered six associated preoperative conditions: tarsal coalitions, peroneal damage, hindfoot varus, OS Trigonums, anterior tibial spurs and lateral gutter ossicles. The six-year study constitutes one of the first regarding ankle injuries in the military, Strauss said.

Untreated conditions, continued pain

Investigators found that numerous pathologies co-existed with ankle instability. “Peroneal injuries occurred with the highest frequency at 27%,” Strauss said. Other afflictions included OS Trigonums (13%) and lateral gutter ossicles (10%), investigators reported in their abstract. They discovered hindfoot varus in 15 of the 180 patients, Strauss said. “The anterior tibular spurs and tarsal coalitions occurred with the least frequency,” he said. The conditions demonstrated rates of 3% and 2% respectively, he said in the abstract.

Researchers reviewed the cases of 105 men and 55 women with an average age of 28.3 years, Strauss said. Nine men and 11 women underwent revisions. Patients waited an average of 11.5 months from the time of injury to examination. A single surgeon performed all the initial operations using the Brostrom technique.

Investigators researched radiographs, clinical reports and health exams. Thorough physical examinations determined the presence of additional injuries. Investigators evaluated OS Trigonums and tibial spurs by impingement tests with forced flexion. They used peroneal tendon subluxation tests to discover tendon breaks, Strauss said. Researchers took six plain radiographs of problematic areas, but “stress radiographs were not performed based on the senior author’s experience with clinical examination,” Strauss said. Patients also performed balance tests to explore instability.

Strauss offered surgeons tips to avoid these conditions and the possible need for additional surgery. “The importance in lessons learned was for those to maintain a high index of suspicion for associated conditions,” he said. “Determine if they are contributing to the problem. Prep dynamic time for varus abnormalities, excise symptomatic OS Trigonums, tibial spurs and lateral gutter ossicles.” Strauss also advised fusion for troubling tarsal coalitions and debridement of peroneal tendon tears.

For more information:
Strauss JE, Lippert FG. Chronic lateral ankle instability: incidence of associated conditions and rational for treatment. #130. Presented at the American Academy of Orthopaedic Surgeons 72nd Annual Meeting. Feb. 23-27, 2005. Washington.