spare parts surgery means use of parts from non - salvageable digits in replantation or cross replantation ( amputated non - replantable digits used to reconstruct thumb ) . it is a well - established procedure in microsurgery . here , we present a case of harvesting double free flaps from an amputated non - replantable lower limb for the contralateral limb .
this is based on the gillies principle , which states -do not throw away any tissue .
this opportunity does not come very often in the clinical practice and one must be ready to grab it when it does ! to the best of our knowledge , there are a very few reported cases , where double free flaps from the amputated limb or digit has been used for spare parts surgery .
a 45 year old male patient who was run over by a train resulting in a right leg amputation at the level of the knee and a crush injury of the left foot .
the right lower limb had a severe comminution and bone loss at the knee joint , with the loss of skin and soft- tissue and crushing of muscle above and below the knee [ figures 1 and 2 ] .
the left forefoot was completely degloved and all the toes were crushed and degloved as well [ figures 3 and 4 ] .
amputated right lower limb right lower limb amputation stump crushed left foot - dorsal aspect crushed left foot - plantar aspect the right lower limb was deemed not replantable as the knee joint was severely damaged and not salvageable , in addition , debridement of crushed and devitalized tissues would result in a 15 - 20 cm shortening and a limb that was at least 15 cm short with fused knee joint would not be functionally useful and primary insertion of prosthetic knee joint was not considered to be feasible by the attending orthopaedic surgeon .
focus was then shifted to the crushed left foot with a view to perform immediate debridement and early soft - tissue cover , to salvage as much of the foot as possible and get it fully healed and weight bearing at the earliest .
stable and sensate skin cover were vital , as this would be the only surviving foot . a large defect such as this would require a large distant flap or even two flaps .
best replacement for skin on the foot was anatomically identical skin from the opposite foot , which in this case was provided by the well - preserved amputated limb .
the general condition of the patient was stable and he had no other life - threatening injuries .
immediate double free tissue transfer from the amputated limb was done . a plantar flap based on the posterior tibial vessels [ figure 5 ] and a dorsal flap based on the dorsalis pedis vessels [ figure 6 ] , with the communication between the dorsal and plantar systems left intact through the deep branch of the 1 dorsal metatarsal artery .
satisfactory inset of dorsal flap [ figure 7 ] , and of plantar flap [ figure 8 ] was achieved . post - operatively the patient developed a hematoma below the dorsal flap . since flaps were harvested from the amputated limb , small blood vessels that could not be seen were probably left unligated . re - exploration and evacuation of hematoma was performed .
harvest of flap from plantar aspect harvest of flap from dorsum inset of plantar flap long - term follow - up - dorsal flap long - term follow - up - plantar flap
for years surgeons have been amputating limbs  at a higher level in limb crush injuries , to ensure good skin and soft - tissue cover for the stump and to make the stump more appropriate for prosthesis fitting .
covering the stump with vascularised tissue using the microvascular techniques from another part of the body has now become common . in crush injuries of the foot , very often
, early free tissue cover to replace the lost skin and soft - tissue can avoid an amputation .
this will however require surgery on another part of the body , with additional trauma and scarring .
spare parts surgery , transferring tissue from the amputated limb using microvascular techniques , is one step ahead because it uses tissue that would otherwise have been discarded , without any additional scarring and other such sequelae . since such opportunities are rare and have to be grasped immediately , we need to constantly be aware of this possibility and ready to use it to maximise patient benefit .
if the patient is not haemodynamically stable , the harvested flap can be stored by wrapping in a saline soaked gauze in a sterile container and placing the container in a box of ice or cold water as per the same guidelines as for an amputated limb for replantation . recommended ischaemia times for reliable success with spare part surgery are parallel to that recommended in replantation i.e. , 12 h of warm and 24 h of cold ischaemia for harvesting flaps from amputated digits and 6 h of warm and 12 h of cold ischaemia for harvesting flaps from major amputations .
use of skin preservation solutions to preserve the skin flaps has been tried in an animal model .
furthermore occurrence of haematoma below the flap in spare part surgery is a realistic complication resulting from inability to achieve haemostasis during the harvest of the flap from an amputated 
achieving haemostasis is then a must after perfusion of the flap lest the flap bleeds after perfusion resulting in a haematoma post - operatively .
 bilateral limb trauma poses many possibilities for management . in a situation of bilateral amputation , 
 if the amputated limb is not salvageable or replantation is not advisable , the amputated limb can be used to harvest tissue for free tissue transfer to cover the amputation stump . 
 we describe a case here in which we have used these principles . 