Ankle fractures heal with nonoperative care despite positive stress tests

No link found between clear space measurements and MRIs of complete deltoid disruption.

PHOENIX — The adequacy of stress tests to indicate operative treatment for lateral malleolus fractures has been questioned by a recent investigation by researchers who introduced a novel protocol for determining surgical intervention.

Kenneth J. Koval, MD, of Lebanon, N.H., examined 15 patients with lateral malleolus fractures (5 mm or more of clear space) and positive stress test results. During 1-year follow-up, he discovered that all of the fractures healed nonoperatively and 14 patients had perfect AOFAS scores.

The patients also reported an average 0.87 score on a 10-point visual analog scale (VAS) for pain and had comparable function to the non-treated ankle.

"Does a positive stress test indicate the need for operative intervention?," Koval asked during his presentation at the Orthopaedic Trauma Association meeting. "I think that, clearly, we can say that, 'No, it does not.'"

To accurately determine the need for surgery, Koval devised a new protocol using MRIs. Patients with signs of medial injury and negative stress tests receive walking boots, while those with positive tests showing large subluxation and syndesmotic injury undergo surgery.

"If the stress test is positive with 5-mm or more gap ... I offer the patient the option — either I could operate on them based on the standard care or I take a MRI," Koval said. He suggests fixation when MRIs show potentially disrupted deltoids or boots for intact or partially disrupted structures.

Of the 21 patients included in the study, MRIs revealed that 19 patients with positive ankle stress tests had partially torn deep deltoid ligaments and two had complete tears. Surgeons operated on the complete tears, and the remaining patients received nonoperative treatment.

"Clear space measurements on stress radiograph testing did not correlate with MRI findings for complete deltoid disrupture, and patients with MRI evidence for partial or intact deep deltoid ligament rupture did well with nonoperative treatment," Koval said.

Of the 15 non-operative patients available at final follow-up, 13 rated their pain as 0 or 1 on the VAS and two patients ranked their pain as a 3. "On X-rays, all fractures had united with no evidence of subluxation, no evidence of residual clear space widening and no ankle had any evidence of abnormality," Koval said.

The findings give a glimpse into the number of patients undergoing unnecessary surgery for ankle fractures, Koval said. "The MRI enabled us to identify and devise effective nonoperative care [in] the 19 patients who would have otherwise had surgery," he said. "But, further work is needed to confirm these results with a larger sample size without using MRI."

For more information:
Koval KJ. Does a positive ankle stress test indicate need for operative treatment? #24. Presented at the Orthopaedic Trauma Association 22nd Annual Meeting. Oct. 4-7, 2006. Phoenix.
Kenneth J. Koval, MD, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756. He can be reached at (212) 598-6137 or kjkmd@yahoo.com.