Total ankle arthroplasty improved gait in patients with OA, rheumatoid arthritis

Researchers found no statistically significant differences in temporal spatial, kinematic and kinetic parameters between cohorts.

Issue: November 2016

TORONTO — Total ankle arthroplasty yielded superior preoperative and postoperative parameters of gait among patients with osteoarthritis, while greater improvements in parameters of gait were found among patients with rheumatoid arthritis, according to study results presented at the American Orthopaedic Foot and Ankle Society Annual Meeting.

“Total ankle arthroplasty improves function for post-traumatic rheumatoid arthritis [RA] patients and osteoarthritis [OA] patients,” Justin M. Kane, MD, said in his presentation. “However, preoperative diagnosis cannot be used as a surrogate to predict the functional improvement after total ankle arthroplasty.”

Total ankle arthroplasty

Kane and his colleagues performed a retrospective review of 76 patients who underwent isolated total ankle arthroplasty with a minimum of 1-year follow-up and were categorized into an OA cohort, an inflammatory arthritis cohort and a post-traumatic arthritis cohort. Researchers performed gait studies at 2 weeks prior to surgery and at 1-year post-surgery and determined the influence of patient variables on parameters of gait by using multivariate analysis to evaluate gait function for postoperative improvement.

According to Kane, each patient cohort had improvements across numerous parameters of gait. However, none of the improvements reached normal gait function. When looking at temporal spatial parameters, researchers found patients with RA had the slowest preoperative cadence and the fastest postoperative cadence. While patients with RA had the greatest improvement in walking speed, results showed patients with OA had the greatest increase in walking speed.

In kinematic parameters, the greatest improvement in maximum plantarflexion and the least improvement in maximum dorsiflexion was found among patients with RA. However, the least improvement in maximum plantarflexion and the most improvement in mean maximum dorsiflexion was found among patients with OA. Patients with OA also had the greatest improvement in total range of motion.

Kinetic parameters showed the greatest improvement in peak ankle power was found among patients with RA, while the greatest postoperative power was found among patients with OA.

“When we looked at the improvement between the groups, we did an analysis of variance with multivariate regression between the three cohorts,” Kane said. “We were unable to detect statistically significant differences for preoperative, postoperative and improvement in function for temporal spatial parameters, kinematic parameters or kinetic parameters.”

Large scale studies

According to Kane, with the current study being underpowered, future research should be on a larger scale, multi-centered and look at a number of parameters, as well as other surgical procedures to treat end-stage ankle arthritis, such as ankle arthrodesis.

“The foot and the ankle are unique,” Kane said. “We are not like the other joint replacement groups, where if you have knee arthritis, you get a knee replacement. You have the ability to get a fusion or an arthroplasty with ankle arthritis, and there is a lot of conflicting literature out there. I think the next step for anybody who is doing research on this is to do a larger scale study to see who is going to benefit most from each procedure.” – by Casey Tingle

Reference:
Kane JM, et al. Functional parameters of gait following total ankle arthroplasty: Is preoperative diagnosis predictive of outcome? Presented at: American Orthopaedic Foot and Ankle Society Annual Meeting; July 21-23, 2016; Toronto.

For more information:
Justin M. Kane, MD, can be reached at Baylor University Medical Center, 3500 Gaston Ave., Dallas, TX 75246; email: jkane.md@gmail.com.

Disclosure: Kane reports no relevant financial disclosures.