Quantitative methods and criteria for modifying and defining transtibial prosthetic alignment: A systematic review

This study aimed to better understand the various objective techniques employed for evaluating and correcting prosthetic alignment and examine proposed methods to define a predefined (a priori) alignment criterion grounded in clinically accepted alignment. A comprehensive search of 5 online databases and a hand search of reference lists of the included papers were conducted. The American Academy of Orthotics and Prosthetics checklists were used to assess the quality of included studies. A total of 247 adults with transtibial amputations participated in the 20 studies included in this study. These studies vary in methodology, approach, instrumentation, and alignment steps. The results indicate that none of the tested methods can replace the current clinical approach. Nevertheless, some techniques can assist the prosthetist in quantifying and adjusting alignment, such as using instruments to measure the moments at the base of the socket or visualizing the ground reaction force. Based on current evidence, it is not possible to define a universal priori alignment because of individual differences and the complexity and multifactorial nature of alignment. However, each prosthetic user appears to have a specific alignment configuration that they find acceptable. Combining various techniques, such as anatomical-based alignment and biomechanical measurement tools, may help to objectively quantify a priori alignment for an individual.