• Neural and trophic signaling governs limb regeneration across vertebrates: higher nerve fiber density, intact innervation, and nerve-derived factors correlate with regrowth; denervation impairs regeneration while targeted trophic interventions can enhance it [1][10][9][11][4][2].

• Non-neural tissues can provide trophic signals enabling limb regeneration in contexts of sparse innervation or specific developmental stages, evidenced by induction in newborn opossum, amphibians with limited neural input, and denervated recoveries [2][5][17][14][7].

• Clinical and biomechanical interfaces—prosthetic fixation, trancutaneous interfaces, and amputation level selection—emerge as critical determinants of tissue responses and functional restoration, shaping regeneration prospects alongside surgical techniques [3][12][16][13][19].

• At the cellular level, studies link DNA/RNA/protein synthesis, myelinated/unmyelinated fiber ratios, and growth factors to regenerative capacity; quantitative EM analyses and NGF interventions illuminate the molecular basis of nerve-regeneration relationships [10][6][9][1][11].

• Regenerative potential varies with species and developmental stage—adult vs juvenile, amphibian vs reptile vs mammal—informing level selection, prognosis, and amputation strategies in clinical limb restoration [18][7][2][12][16].