(A) Seahorse Mito Stress Test (oxygen consumption rate, OCR; extracellular acidification rate, ECAR) and Glycolytic Rate Assay (glycolygic proton efflux rate, GlycoPER) of dissected blastema from aged mice treated with oxaloacetate (OAA) (Oligo, oligomycin; R/AA, rotenone/antimycin A). (B) Micro-computed tomography (micro-CT) quantification of trabecular bone volume (Tb. BV.), trabecular thickness (Tb. Th.), and trabecular separation (Tb. S.) of regenerated OAA treated bone at day 21 and day 28 post amputation, relative to time-matched, saline-treated controls. n=11–19 digits/group. Graphs represent average values ± SEM. *p<0.05, **p<0.01, ***p<0.001. (C) Representative whole (top) or bisected (bottom) day 28 digits from saline control or OAA-treated mice. (D) 2D micro-CT analysis of regenerated bone from the remaining P3 cortical bone stump extending distally from aged saline control and OAA-treated mice.