The Threshold of Physical Fitness in terms of Maximum Oxygen Uptake as a Predictive Factor for Achieving Prosthetic Walking in Elderly with Unilateral Trans-femoral Amputation or Hip Disarticulation

Abstract

The aim of this study was to determine the threshold of physical fitness level in terms of maximum oxygen uptake as an important predictive factor for achieving prosthetic walking in elderly with unilateral trans-femoral amputation or hip disarticulation. Subjects were 69 amputees aged 60 and above. Mean age was 67.3±5.5 years (Range 60-81 years). All of them were hospitalized at our Center for prosthetic walking training and who had never been fitted with prosthesis before. The incremental exercise test was performed to evaluate physical fitness before they began prosthetic rehabilitation. After completion of the rehabilitation program, they were asked to walk at comfortable walking speed to evaluate their prosthetic ambulation ability. Subjects who could walk at least 100 meters without ambulatory aids or with only one cane were classified as successful prosthetic users. All others were classified as failed prosthetic users. There were 47 amputees in success group and 22 in failure. Other clinical information about each patient before fitting prosthesis was collected retrospectively from their charts. Significant difference was observed between the groups in cause of amputation, the number of comorbidities, ability to stand on the non-amputated leg, and physical fitness. Logistic regression analysis showed that maximum oxygen uptake as a proportion of predicted maximum oxygen uptake (%VO2max) was found to be significantly related to successful prosthetic walking. The ROC analysis showed that the threshold of %VO2max was 53.9, its sensitivity was 79% and
specificity was 92%. Our results showed the prognosis of prosthetic rehabilitation in elderly amputees on the basis of physical fitness. Incorporating other predictive factors with the findings of this study is essential to increase predictability.