Fig. 2: Flow diagram of included studies.

Data from 134 publications were included in the meta-analysis and study quality/design assessment. Following data extraction, the analysis was conducted based on the set objectives. Of the included studies, 91 papers reported locomotor recovery outcomes, 72 reported in vivo axonal regeneration outcomes and 21 reported in vitro axonal regeneration. Objective 1 includes only comparisons that assessed the effect of biomaterials alone. Objective 2 includes studies that assessed BMC strategies in vitro, in vivo, and/or studied the biomaterial properties. Objective 3 includes studies that carried out investigations only in vivo.