from Henry 2008:
Although there is ample experimental and clinical evidence supporting the use of magnetic fields to aid bone healing, its application for soft tissue healing, including skin and tendons, is still ambiguous. Promising research along these lines was first produced in the 1960s by Becker. Studying amphibians, he described the presence of an electromagnetic skin circuit, alterations which accompanied limb regeneration.18 Borgens et al confirmed that this current is essential for amphibian limb regeneration and that its reversal induces limb degeneration.19,20 In a study involving limb amputations in frogs, a species that does not naturally produce this current and that is normally incapable of limb regeneration, induction of this current stimulated the regeneration of a rudimentary limb that included cartilage, nerve, and skin tissues.20 These skin circuits have been identified in humans and are similar in magnitude to those demonstrated in amphibians.21 Given this fact, it is plausible that external magnetic therapy could influence soft tissue healing in humans as well.
Singh 2015:
Current data suggests good or excellent outcomes in over 75% of flexor tendon repairs.54 Rupture occurs in 4-10% of finger flexor repairs and 4-17% of long thumb flexor repairs.54 Modern tissue engineering approaches and focused rehabilitation protocols are the future avenues for further improving recovery.