The contemporary transfemoral socket standard of care is the ischial ramus containment (IRC) design. Removal of the IRC brim, however, could be beneficial by improving hygiene, comfort, and mobility and reducing perspiration and fitting complications. To this extent, researchers from the School of Physical Therapy and Rehabilitation Sciences, University of South Florida, Tampa, conducted a study to investigate the effect of brimless compared with IRC prosthetic sockets when using vacuum-assisted suspension on persons with a unilateral transfemoral amputation. The results were published in a recent issue of the Journal of Rehabilitation Research & Development (issue 50-9).
The purpose of this study was to determine whether a brimless socket would compromise coronal hip angle and socket movement, increase skin pressure, and be more preferable to patients than the standard of care IRC socket. If vacuum-assisted suspension does favorably affect these variables, then the IRC brim’s purpose may be biomechanically diminished. The study design was a randomized crossover clinical trial with two socket conditions: IRC vacuum-assisted suspension and brimless vacuum-assisted suspension. Nine individuals with a unilateral transfemoral amputation were enrolled. Main outcome measures included coronal hip angle and vertical and lateral socket movement as measured by x-ray, skin pressure measured by Tekscan, and preference measured subjectively. The brimless design was found to be statistically equivalent to IRC in all measured coronal hip angles and vertical and lateral socket displacement. The peak/stance mean pressure in the medial proximal aspect of the socket was 322 mmHg in the IRC compared with 190 mmHg in the brimless condition. Except for medial proximal pressure, no other measures reached statistical significance. Further, all subjects reported the brimless design to be more comfortable than the IRC in short-term preference.
Given these results, the researchers concluded that the brimless vacuum-assisted socket design may be a clinically viable choice for people with transfemoral amputations. They stated, however, that future studies should also observe overall gait kinetics and kinematics, and further research is necessary to better understand transfemoral socket design options.