We evaluated the maturation of grafted bone in
cases of successful fusion after a one- or two-level posterior lumbar interbody
fusion (PLIF) using interbody carbon cages. We carried out a five-year
prospective longitudinal radiological evaluation of patients using
plain radiographs and CT scans. One year after surgery, 117 patients
with an early successful fusion were selected for inclusion in the
study. Radiological evaluation of interbody bone fusion was graded
on a 4-point scale. The mean grades of all radiological and CT assessments
increased in the five years after surgery, and differences compared
to the previous time interval were statistically significant for
three or four years after surgery. Because the grafted bone continues
to mature for three years after surgery, the success of a fusion
should not be assessed until at least three years have elapsed.
There were no significant differences in the longitudinal patterns
of grafted bone maturity between iliac bone and local bone. However,
iliac bone grafting may remodel faster than local bone.
1. Into osseous defects cut in the pelvis of rats, Kiel bone grafts were implanted after impregnation with the animals' own fresh bone marrow, obtained by femoral puncture. Unimpregnated Kiel bone grafts and Kiel bone grafts impregnated with an antibiotic solution were implanted as controls. 2. Histological examination of the implant area showed that in the marrow-impregnated grafts new bone formation could be observed after twelve days, and that during an observation period of 135 days after implantation bone formation occurred in thirteen out of nineteen rats. In four of these cases a
