Lj. Curylo et al., Augmentation of spinal arthrodesis with autologous bone marrow in a rabbitposterolateral spine fusion model, SPINE, 24(5), 1999, pp. 434-438
Study Design. Posterolateral spinal fusion with autologous bone marrow aspi
rate in addition to autograft iliac crest bone graft in a rabbit model.
Objective. To demonstrate that the addition of autologous bone marrow can h
ave positive effects on bone formation and spinal fusion.
Summary of Background Data. Bone marrow has been shown to contain osteoprog
enitor cells. A number of studies have demonstrated that bone formation is
possible with autologous marrow injection into orthotopic sites such as tha
t performed in femur fracture models.
Methods. A bone paucity model of posterolateral spine fusion was developed.
The control animals received 0.8 g of morselized autogenous iliac crest bo
ne graft harvested from a single iliac crest. The graft was mixed with 2 mt
of clotted peripheral blood. In the experimental group, 2 mt of bone marro
w aspirated from the opposite iliac crest was substituted for the periphera
l blood clot. All rabbits were killed at 12 weeks, and the specimens were s
ubjected to evaluation by posteroanterior radiography for the presence of f
usion, computed tomography for bone volume, and biomechanical testing for s
tiffness.
Results. Successful fusion was achieved in 61% of the animals in the experi
mental group verses 25% in the control group (P < 0.05). The fusion mass in
the experimental group had a mean volume of 919 +/- 387 mm(3) verses 667 /- 512 mm(3) for the control group, as measured from computed tomography im
ages. The results of the biomechanical testing validated the radiographic s
coring system. The stiffness in specimens, graded as having a radiographic
score of 4, was significantly greater than in specimens with radiographic s
cores of 1 and 2.
Conclusion. In cases for which an adequate quantity of autogenous bone graf
t is not available, addition of bone marrow may facilitate greater bone for
mation and successful fusion.