الجواب وبالله التوفيق
When any human limb becomes disabled or its benefit ceases then for the grafting done to revive its functionality, in view of giving due respect to the human limbs, the first priority resides with the usage of artificial things or the limbs of the Halaal animals. As long as these things are available neither it would be permissible to use human limbs for one’s own self nor for other people.
However, when there is no hope of the availability of these things then in case of extreme necessity first priority will be for one’s own limbs (on condition that the expert doctors have utmost expectation of cure using these limbs).
In the second level will be the usage of the limbs of some other human being whether he is deceased or alive on condition that it is with their permission and the living donor wouldn’t get harmed himself.
In the absence of these two scenarios, the grafting will be done with your own tissue.
As far as the issue of delay in the recovery time, apparently this doesn’t seem to be such a necessity for which an impermissible act
(The usage of the limbs of a third person) is declared permissible. Nevertheless, if a quick recovery is in the realm of necessity for you then this would be permissible too. However, the cautionary approach is that your own tissue is used in the grafting.
قال النبی صلی اللہ علیہ و سلم: کسر عظم المیت ککسرہ حیًا
سنن ابی داؤد، کتاب ۲۰، باب ۵۸
واللہ اعلم بالصواب