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Alexander Y. Shin, MD, and Allen T. Bishop, MD<br />
Otherwise, a salvage procedure<br />
should be done. Under direct visualization<br />
and fluoroscopic image,<br />
necrotic bone is removed from the<br />
lunate with a burr or curettes, leaving<br />
a shell of intact cartilage and<br />
subchondral bone through a dorsal<br />
opening. If collapsed, the lunate is<br />
gently expanded to normal dimensions<br />
with a small blunt-ended<br />
spreader. At this time, the tourniquet<br />
is deflated to verify blood flow<br />
to the graft. Cancellous bone graft<br />
harvested from the distal radius<br />
bone graft defect is packed into the<br />
lunate, followed by insertion of the<br />
VBG, orienting the pedicle vertically<br />
with the cortical surface placed in a<br />
proximal-distal orientation. This<br />
allows the graft to serve as a strut to<br />
help maintain lunate height during<br />
revascularization (Fig. 6). Internal<br />
fixation of the graft to the lunate is<br />
unnecessary.<br />
Unloading of the lunate is important<br />
during the revascularization<br />
process and may be accomplished<br />
by external fixation, capitate shortening,<br />
intercarpal arthrodesis, or<br />
temporary pinning of the intercarpal<br />
joint. Although external fixation<br />
was commonly used as a method of<br />
unloading the lunate, we favor<br />
scaphocapitate pinning with two<br />
percutaneously placed 0.0625-inch<br />
K-wires, which are cut subcutaneously,<br />
for 8 to 12 weeks. The temporary<br />
scaphocapitate pinning<br />
avoids the pin site problems associated<br />
with prolonged external fixation.<br />
The wrist capsule is replaced,<br />
the extensor retinaculum repaired,<br />
and a long-arm bulky hand dressing<br />
applied.<br />
Postoperatively, the bulky hand<br />
dressing is removed at 10 to 14 days<br />
and is replaced with a long-arm cast<br />
for 2 to 3 weeks. At 3 weeks postoperatively,<br />
the cast is removed and<br />
gentle, supervised, limited wrist<br />
flexion and extension is begun. The<br />
wrist is protected with a custommade<br />
plastic splint for the next 8 to<br />
9 weeks. The scaphocapitate K-wire<br />
A<br />
Figure 6 Pedicled VBG for Kienböck’s disease. A, The anterior interosseous artery is ligated<br />
proximal to the fourth and fifth ECAs, and graft elevation is completed. After verifying<br />
blood flow, the graft is shaped to fit the dorsal opening to the lunate. B, Cancellous<br />
bone is packed into the lunate. The VBG is inserted with the pedicle placed vertically and<br />
the cortical surface oriented proximal-distal. (Adapted with permission from the Mayo<br />
Foundation, Rochester, MN.)<br />
fixation is removed under local anesthetic<br />
at 12 weeks.<br />
Results<br />
The results of nine VBGs obtained<br />
from the radial metaphysis in<br />
patients with stage IIIA Kienböck’s<br />
disease, using reverse-flow pedicles,<br />
have been reported. 17 The grafts<br />
were based on the 2,3 ICSRA in two<br />
patients, fourth ECA in four, fifth<br />
and fourth ECAs in two, and palmar<br />
radiocarpal arch in one. The procedure<br />
was used without joint leveling<br />
in four patients who had ulnar neutral<br />
or positive variance, while three<br />
patients with ulnar negative variance<br />
had a concomitant radial shortening.<br />
All but one patient had external<br />
fixation for temporary lunate<br />
unloading. Follow-up averaged 32<br />
months (range, 7 to 90 months). Grip<br />
strength improved 25%, ultimately<br />
measuring a mean of 86% of the<br />
opposite side (range, 60% to 100%).<br />
Range of motion was not significantly<br />
different from preoperative status.<br />
Radiographic measurements demonstrated<br />
no change in the modified<br />
carpal height ratio, lunate index, or<br />
scapholunate angle. Only two<br />
patients were without collapse preoperatively,<br />
based on carpal height<br />
ratio values. Both progressed postoperatively,<br />
although absolute numeric<br />
change was slight. Magnetic resonance<br />
imaging data demonstrated<br />
progressive signs of revascularization<br />
over time, with normalization<br />
of T2 images seen initially by 18<br />
months, followed by normalization<br />
of T1 images by 36 months.<br />
Summary<br />
Vascularized bone grafts from the<br />
dorsal distal radius can be effectively<br />
applied to treat carpal problems<br />
such as scaphoid osteonecrosis and<br />
nonunion as well as Kienböck’s disease.<br />
Although the vascular anatomy<br />
of the distal radius provides the surgeon<br />
with several alternative grafts,<br />
we have found the 1,2 ICSRA pedicle<br />
to be most useful for the scaphoid<br />
and the fourth and fifth ECAbased<br />
graft desirable for lunate<br />
B<br />
Vol 10, No 3, May/June 2002 215
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