We found that the use of a hand-carved silicone-rubber (Silastic) spacer
was reasonably effective in relieving symptoms in thirty-six patients with
advanced Kienbock's disease, even though there was still some residual
postoperative loss of wrist motion and grip strength. Preoperatively all
patients had pain and limited motion of the wrist as well as weakness of
grip. Roentgenographically all had fragmentation and collapse of the
lunate, and 92 per cent had measurable carpal collapse. Most had had
symptoms for longer than one year. After removal of the deformed lunate
through a dorsal incision, a silicone-rubber spacer was shaped to fit the
defect. Patients were followed for an average of fifty-four months.
Thirty-two patients were followed for at least two years; all but three
were improved. This procedure is not recommended when the shape of the
lunate is normal or not significantly altered, or when the lunate has not
collapsed as measured by precise determinants.