Brief reviw
*Title: Threaded fusion cages for lumbar
interbody fusions. An economic comparison with 360 degrees fusions
*Author: Charles Dean
Ray
*Bibliography: Spine(Phila Pa 1976). 1997 Mar 15;22(6):681-5
STUDY DESIGN
-Compared the
surgical and hospitalization costs, operating times, and blood loss
attributable to lumbar interbody fusions at one and two lumbar levels by the
use of two device systems
:1) the Ray Threaded
Fusion Cage, and 2) an anteroposterior interbody technique with pedicle screw
and rod stabilization (360 degrees fusion).
-Prospective cohort
study
-The clinical
efficacy and complication rate of each method were similar.
OBJECTIVES
Data were analyzed to
compare the newer threaded fusion cage method with the well established 360
degrees technique.
SUMMARY OF BACKGROUND DATA
-Interbody bone
grafts are a proven concept to obtain solid spinal fusions.
-A variety of
mechanical means are used to stabilize the graft material during the fusion
growth
and have been shown
to be important in facilitating both the rate and ultimate quality of the
fusion.
METHODS
▶Number of
Subjects: 50 patients having severe,
disabling back pain with discal degeneration (1991~1995)
- Ray Threaded Fusion
Cages: 25
Anteroposterior interbody fusion
procedures using pedicle screws (360 degrees technique): 25
-All implants were
performed by the same surgeon in the same hospital.
-All fusions were
judged solid by established radiologic criteria.
-Cost comparisons
were made from pertinent medical records using inflation-corrected 1995 U.S.
dollars.
RESULTS
▶The
average combined (surgeon, hospital, anesthesiologist) costs
*1 level / 2 level
- threaded fusion
cage: $25,171 / $33,113
-360 degrees
procedures: $41,813 / $47,320
(difference: 40% or
$16,642 / 30% or $14,207)
▶The
average saving
-threaded fusion cage:
$14,639 per case (total $365,975)
-360 degrees
procedures: $365,966 (total)
-10 of the 360
degrees fusion cases required later instrumentation removal, adding $8,635 to
the costs of each such case, a final difference of $22,889 compared with an
equivalent threaded fusion cage case.
-The actual
collections on threaded fusion cage cases were 81% of billed costs and the
actual collections on 360 degrees cases were 73% of billed costs.
CONCLUSIONS
-Assuming that the
fusion success, clinical outcome, and complication rates are sufficiently
similar between these two techniques, the striking improvement in overall
surgical and hospitalization costs, surgical time, and blood losses provided by
the threaded fusion cage technique can be major decision points in method
selection.
-Further, no threaded
fusion cage case having a normal adjacent level preoperatively developed a
fusion transition syndrome over a followup period from 3 to 29 months
(averaging 24 months) that required a second fusion procedure, and no cage had
to be removed because of instrumentation-associated pain, although each of
these problems are known to occur in at lease 10% of pedicle screw implants.
Ten of the 25 (40%)
360 degrees fusion cases in this study required subsequent instrumentation
removal, although no case has required adjacent level surgery for transition
syndrome.
