Severe ankle arthritis is less common than hip or knee arthritis but just as disabling. So say researchers at the VA Medical Center in Seattle Washington. Researchers from the Mechanical Engineering and Orthopaedics and Sports Medicine centers at the University of Washington assisted in this study.
They studied 37 patients (men and women) who were expected to have ankle surgery for severe arthritis classified as end-stage arthritis. All patients in the study had failed to achieve pain control or improved function with conservative (nonoperative) care. Surgery to either fuse the ankle or replace it was scheduled.
The purpose of the study was to measure the impact of this type of ankle arthritis on function referred to as impairment of function. They used several different ways to assess function including counting the number of steps taken each day, step length, walking speed, and ankle motion. These measurements were compared to normal, healthy adults of the same age and sex (male or female) who did not have any ankle problems.
Some of the considerations in this study were the fact that many of the patients developed severe ankle arthritis as a result of a traumatic injury. And they were younger than the typical older patient who develops degenerative arthritis as a result of the aging process.
Choosing between ankle fusion (called arthrodesis) and ankle replacement (arthroplasty) is always a challenge. Fusion limits pain because it stops ankle motion. But loss of ankle and foot motion causes changes or alterations in the walking (gait) pattern. That in itself can cause further problems later on. Ankle replacement restores ankle motion and takes the pressure and load off the other nearby joints. But long-term studies of ankle replacement are not showing outstanding results at this time.
The question then becomes: is function affected by end-stage ankle arthritis? If so, how can we measure the amount of disability? At what point do the results of these tests suggest surgery is the best treatment? And finally, which type of surgery is best: fusion or replacement?
Not all of these questions were answered by this study. But the researchers at least got a start on evaluating which tests and measures provide the most information about function and activity limitations. And they began to see how the effects of end-stage ankle arthritis impact health and quality of life for these patients.
Analysis of the data showed that everyone had decreased ankle motion and power compared to the unaffected side. Average walking speed, number of steps taken each day, and length of steps were less than those of normal (control) adults. These measures were also correlated with physical function. Just moving around a room took more energy, more steps, and more time compared with normal, healthy adults. Those patients who had better physical function also had less pain and a better mental attitude.
In summary, the tests used in this study did help identify problems with ankle motion and function. It is likely that these same measures could be used in future studies. They could be used before and after treatment to see the effects or value of each treatment provided.
Reference: Ava D. Segal, MS, et al. Functional Limitations Associated with End-Stage Ankle Arthritis. In The Journal of Bone and Joint Surgery. May 2, 2012. Vol. 94. No. 9. Pp. 777-783.