Ankle arthrodesis restores function after treatment of osteoarthritis, study finds

Plantar pressure can be restored to conditions nearing those of original functionality.

Ankle arthrodesis can restore plantar pressure distribution to almost physiological conditions nearing those of the contralateral foot, according to a study.

The findings were presented by Reinhard Schuh, MD, at the 2010 Summer Meeting of the American Orthopaedic Foot and Ankle Society (AOFAS) in National Harbor, Md.

Schuh said that in vitro studies have revealed that ankle arthrodesis can restrict kinematics more than total ankle replacement in regards to both range of motion and movement transfer, but little has been studied in terms of in vivo gait patterns.

“The purpose of the study was to determine plantar pressure distribution and clinical results in patients who underwent isolated unilateral ankle fusion by a single surgeon with follow-up,” he said.

Study methods

In the retrospective study, researchers studied 21 patients who underwent isolated unilateral ankle arthrodesis with three crossed 7.3-mm AO screws in a standardized technique performed by one surgeon between Oct. 2000 and Jan. 2008.

At a mean follow-up of 25 months, researchers performed pedobarography, clinical evaluation with AOFAS hindfoot scores and standing X-rays of each patient’s foot.

Positive results

Schuh reported that 19 patients were available for the follow-up, and none showed any sign of nonunion. Sixteen patients were found to have been “very satisfied” with the result of the operation, with two saying they were “satisfied” and one saying they were “not satisfied.”

Schuh added that pedobarographic assessment showed the technique had achieved clinically impressive results.

“There were no statistically significant differences in maximum force in any regions of interest,” he said.

The study noted no statistically significant differences between the operated foot and the contralateral foot in terms of peak pressure, maximum force, contact area or contact time.

Radiographic analysis revealed an ideal position of the arthrodesis in the sagittal plane in 84% of the patients with less than 5· standard deviation of neutral position. AOFAS score was also shown to have changed for the better, with an average reported score of 80.5.

“Eighty percent of the patients reached good to excellent results in terms of AOFAS score,” Schuh said.

Restoration of function

The study’s results point toward ankle arthrodesis for the treatment of isolated unilateral osteoarthritis being a viable treatment in terms of restoring function, Schuh reported.

“Based on the results of the present study, we strongly believe that isolated unilateral ankle arthrodesis can provide a good functional outcome,” he concluded. – by Robert Press

Reference:

• Schuh R, et al. Plantar pressure distribution after tibiotalar arthrodesis. Presented at the 2010 Summer Meeting of the American Orthopaedic Foot and Ankle Society. July 8-10, 2010. National Harbor, Md.

• Reinhard Schuh, MD, can be reached at the department of orthopaedic surgery at Innsbruck Medical University, Innrain 52 6020 Innsbruck, Austria 0512 5070. He has no direct financial interest in any products or companies mentioned in this article.

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