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Page 6 of 15 Crowe et al. Plast Aesthet Res 2019;6:4 I http://dx.doi.org/10.20517/2347-9264.2018.70

Figure 2. Prosthesis for a congenital Syme amputation with patellar tendon bearing proximal cuff and distal build up due to a short limb

medial joint line. It is frequently cited that a minimum of 5 cm is required for acceptable function and
prosthesis fitting, though this is not always an absolute requirement. The provider and patient must consider
the advantages and disadvantages of a short limb with joint preservation vs. an above knee amputation.
Amputation in the distal third of the leg, however, is often complicated by the paucity of soft tissue coverage
for the residual limb. A variety of flaps have been described for coverage of transtibial amputations, although
a long posterior, musculocutaneous flap is ideal.

In the case of a traumatic BKA with inadequate local soft tissue for coverage of the residual limb and
borderline bone length reconstructive plastic surgeons are often consulted for residual limb coverage for
length preservation. Goals of reconstruction are to create a soft, pliable, durable interface with a non-
adherent incision (i.e., mobile over bone) in a location 2-8 cm superior to anterior edge. Positioning the
incision line proximal to the distal anterior tibia will prevent the scar from being at the highest pressure,
highest friction location when wearing a prosthesis.

Operative management must take into account the skin and soft tissue, muscles, nerves, and bones. First,
skin closure should be without tension but not redundant. The more skin surface area available for contact
with the prosthetic socket, the less pressure will be applied to each unit area of skin surface. A cylindrical
shaped residual limb with ample muscular padding presents fewer skin problems than the bony, atrophic
tapered residual limb.

In modern amputations with improved prosthetic interfaces such as gel liners, it is possible for split thickness
skin grafts to withstand forces applied by a prosthesis when not adherent to bone. Thus, application of a
skin graft over a vascularized muscle bed is viable method of amputation stump reconstruction. However,
without at least a fine layer of subcutaneous fat or muscle to absorb shear force, grafts are not as durable and
predictably break down. Skin grafting over granulating bone is therefore not advised.

Maximal preservation of functional muscles is essential to provide the limb with strength, size, shape,
circulation, and proprioception. Thus, when native muscle remains but has lost its distal insertion, myodesis
or myoplasty are often helpful. Myodesis tends to be preferred unless bone quality is poor.