Surgical Treatment Of L4/L5 Degenerative Spondylolisthesis - An Outcome Analysis**
In an effort to evaluate the effectiveness of contemporary
treatment for L4/L5 degenerative spondylolisthesis, a prospective
outcomes study was performed on 50 patients using the SF–36
outcome instrument. All patients were diagnosed with a degenerative
L4/L5 spondylolisthesis and had failed non–operative therapy.
They were treated with posterior lumbar decompression and posterolateral
fusion with autogenous iliac crest bone graft by one single surgeon
at one institution. Of these patients, 49 underwent spinal instrumentation
with pedicular screw and rod devices. The average follow–up
was 3.8 years with a 2–year minimum follow–up from
surgery (range 2.3–6.0 yrs). Average age at surgery was
66 years.
SF–36 outcomes questionnaires were administered pre–operatively,
and at 3, 6, 12, and 24 months post–operatively and yearly
thereafter. Statistically significant improvements were found
comparing the pre– operative and post–operative SF–36
scores for bodily pain, physical functioning, role limitations–physical
and the physical component score. This score improvement indicates
patient improvement after the surgery. The paired t–test
revealed p–values of less than 0.05 for each of the above
groups. Estimated mean differences and 95% confidence intervals
were also calculated and support the conclusions.
There were no deaths or neurological complications post–operatively.
5 patients required re–operation, 1 for pseudarthrosis,
1 for deep infection, 2 for spinal stenosis above the fused segment
at 3–4 years after fusion, and 1 for spondylolisthesis above
the fused segment. The average blood loss was 392cc. The average
number of levels fused was 2. This study demonstrates the efficacy
of lumbar decompression and fusion for degenerative L4/L5 spondylolisthesis
by use of a well–accepted outcomes instrument. To the authors'
knowledge, this represents the largest prospective study to date
with this diagnosis and the SF–36 outcome instrument. It
enables us to compare results across specialty line and justify
our approach to this common spinal deformity.
** The FDA has not cleared
a drug and/or medical device for the use described in this presentation.
(i.e., the drug or medical device is being discussed in an “off–label"
use).