Synovial or ganglion cysts usually present in the
joints of the wrists, knees, ankles and feet.
Intraspinal juxtafacet cysts are rare, but recently have been
documented with increasing frequency due to improved imaging capabilities.
Ganglion and synovial cysts were first described in the 60s.
Currently, a definitive diagnosis to distinguish between the two
sorts of cysts is only made via pathologic examination.
While synovial cysts have a lining of cuboid epithelium like synovial cells,
ganglion cysts have a gelatinous, pragnatious
material that is devoid of synovial lining.
However, distinguishing between ganglion and synovial cysts is only of histological
value, as their clinical features, treatment and prognosis are the same.
Although the ideology of intraspinal synovial
cysts remains unclear, it is thought
that the synovial cysts are linked
to spinal degeneration and segmental instability.
Specifically, spinal degeneration has hypothesized to cause protrusion of
the synovial membranes through the defects of the joint capsule.
creating the formation of a para-articular cavity
which maybe filled with synovial fluid or air.
In line with this hypothesis, synovial cysts have been noted to present with
other degenerative spinal conditions such as spondyl,
spondylolisthesis, degenerative disc disease and spinal stenosis.
Our findings show that about 33% of our patients had
underlying spondylolisthesis indeed corroborate the
published studies on this topic.
In addition to the fact that the most mobile level of the spine, the L4, L5
level, is associated with the vast majority of synovial intraspinal cysts.
Again, this was also shown by our study,
where about 58% of our patients noted that.
This supports the notion that segmental instability may be
a significant ideological factor to these cysts pathogenesis.
Patients with intraspinal juxtafacet cysts or
intraspinal synovial cysts typically present with
low back pain, radicular pain, neurogenic
claudication, or very rarely, acchotta aquina syndrome.
Although the symptoms severity depends on the size and the location of the cyst.
Synovial cysts, which occur in the cervical or thoracic
spine are indeed rare, but may present with myelopathy.
In our study, 83% of patients presented with back pain.
98% presented with radiculopathy.
40% with motor weakness.
33% with sensory deficits, and 20% with neurogenic claudication.
3% of our patients had bowel and bladder dysfunction.
Interestingly, we observed a slight female predominance, 54% in our
patient cohort, which has been reproduced by others as well.
An MRI is preferable to a CT in terms of diagnostic imaging, as the former
has a sensitivity close to 90% whereas the CT only has a sensitivity of 70%.
An MRIs synovial cysts will generally appear as well circumscribed, smooth
extraderal lesions that are adjacent and coming from the facet joints.
They are generally hypo-intense on T one
and hyper-intense on T two weighted images.
Intraspinal synovial cysts are typically
surgically treated with multiple different methods.
While some have advocated conservative management of these juxtafacet cysts, it
is clear that most patient eventually fail and require surgery.
Within the past 40 years, cyst excision has
been performed either via
hemilaminectomy, bilateral laminectomy, bilateral laminectomy
with medial facetectomy or bilateral laminectomy and complete
total facetectomy with instrumented or a non instrumented fusion.
The bilateral laminectomy is the, is the
most cited form of treatment in the literature.
Despite these various surgical options that surgeons find themselves
faced with, few have directly compared the various outcome
of these various methods in order to better understand
the benefits and potential drawbacks of each surgical mesh, method.
We conducted a retrospective analysis of outcomes in
patients presenting with intraspinal synovial cysts at a single
institution treated with surgical exition, we separated the
patients based on the treatment modality that they got.
Com, we compare the, the intra and Perry
operative complications as well as the post operative outcomes.
We also assess their relative contribution of each
procedure to the outcome of each surgical cohort.
This is the first study of its kind.
This statistically quantify the efficacies of each surgical outcome individually.
Our study found that patients who received bilateral laminectomy
without fusion had a significantly higher incidence of
recurrent mechanical back pain compared with other surgical cohorts.
Our study also demonstrated that only
patients who received unilateral hemilaminectomy, or
patients who receive bilateral hemilaminectomy experienced
cyst recurrence at the same spinal level.
In contrast, none of the 74 patients who
received complete fasciectomies with fusion experience cyst recurrence.
This increase in cyst recurrence that was seen in patients who did not undergo a
fusion was significantly increased in the laminectomy group with a p of 0.042.
The fact that the most mobile level of the spine, L4-L5, is indeed associated
with the vast majority of these synovial cysts, again replicated by our study
where 58% of our patients presented with cysts at L4-L5, supports the notion that
segmental instability May be a significant etiological
factors to the pathogenesis of these cysts.
Patients who received decompression with an
instrumented fusion had the lowest incidence of
post-operative back pain, which was also significant
when compared to the hemi-lac, hemilaminectomy cohorts.
The takeaway points from this study
is that hemilaminectomy or bilateral laminectomy
remains one of the mainstay surgical
treatments for symptomatic intraspinal synovial cysts.
This retrospective review of 195 symptomatic synovial cysts
surgically treated at a single institution shows that the majority of
patients undergoing decompression and excision of lumbar synovial cysts,
will experience immediate improvement in both Back pain, and leg pain.
However, within two years after surgery, patients receiving
a hemi-laminectomy or a bilateral laminectomy have an
increased incidence of back pain and cyst recurrence
when compared to patients who received the fusion.
Instrumented fusion, in addition to a decompression, appears to reduce
the incidence of cyst recurrence and postoperative mechanical back pain.