Although discussion of pressure sores in the paraplegic patient is confined to the problems of reconstruction, it cannot be emphasised too strongly that the procedures to be described for the various types of decubitus ulceration are only a small facet in the overall care of the paraplegic, and they must be regarded as merely providing the ulcerated area with a fresh start in the best conditions.
The sites in the paraplegic which are particu-larly liable to develop pressure sores lie over the pressure-bearing bony prominences.
Compared with the sores which develop in the non-para-plegic, the ulcers tend to have an ‘iceberg’ qual-ity, with extensive undermining, and osteitis of
the underlying bone, or even pyoarthrosis in severe cases. Surgical treatment consists of the covering of the completely excised ulcer with a movable pad of healthy skin and subcutaneous tissue, and simultaneous reduction of any under-lying bony prominence which appears to be acting as a focal pressure point.
This latter proced-ure is generally essential, since such promi-nences left untouched reproduce the mechanical pressure which was responsible for the original ulcer.
During the acute phase of the spinal injury, the common sites are over the sacrum and femoral trochanter; after recovery, prolonged sitting in a wheelchair makes the ischial area the most frequent site.
Sacral ulcers tend to be large and flat with minimal undermining; ulcers of the trochanter and ischium usually have a small opening, leading into a large slough-lined cavity into the base of which the bony prominence projects.
The anaesthetic tissues of the paraplegic heal
poorly, and with the slightest provocation the wound will fail to heal following surgery.
Tension on suture lines must be avoided, haemostasis must be even more meticulous than usual, cavities and dead space must be positively eliminated -failure in any one aspect will result in failure as a whole. If skin loss is minimal, exci-sion and direct closure may suffice, but in most instances a flap is needed. The secondary defect created by transfer of the flap has often to be grafted and, as discussed on p. 88, the graft need not necessarily be applied at the time of the flap transfer.
The collection of a haematoma under the flap is particularly undesirable in the para-plegic patient, and leaving the secondary defect ungrafted in this way is a valuable way of ensur-ing that a large area is available through which any haematoma can drain instead of collecting under the flap to cause tension, infection and necrosis. The graft can be applied 7-10 days later.