The X-STOP Spacer is the first interspinous spacer shown to be superior to
nonsurgical treatment in patients with neurogenic
intermittent claudication (NIC) due to lumbar spinal stenosis (LSS).
The FDA approved the X-STOP Spacer using data from a 2-year, multicenter,
randomized, controlled study. Research took place in 9 hospitals across the
United States. In this study, 100 patients with LSS were implanted with the
X-STOP Spacer. This group was compared with 91 patients who received nonsurgical
treatment (epidural injections, pain medications, physical therapy, etc.) by
The X-STOP Spacer was shown to be superior to nonsurgical care based on: device
performance measures, need for additional surgery for LSS, and the Zurich
Claudication Questionnaire (ZCQ). The following information details these
criteria and summarizes results from additional analyses of the clinical study
X-STOP Spacer device performance
Assessment of the X-STOP Spacer 2 years after implantation demonstrated:
84% maintenance of distraction (maintenance of the space between spinal
segments as viewed by X-ray)
96% no dislodgement of the implant
94% absence of implant-related complications
Need for additional surgery for LSS
After 2 years, 93% of patients who received the X-STOP Spacer did not require
any additional surgery for LSS. During the clinical study, 7% of the X-STOP Spacer
patients did not consider their outcomes satisfactory and chose to have a laminectomy
or have their device removed.
Patients involved in the clinical study were required to complete a
questionnaire with specific questions about their treatment experience. The
questionnaire, called the Zurich Claudication Questionnaire, is an international
standard that has been scientifically validated to measure specific aspects of
NIC due to LSS. Because the questionnaire is patient-completed, it is able to
measure the patients’ perspectives in regard to their outcomes.
Patients treated with the X-STOP Spacer reported superior improvement in all
three categories: pain, function, and satisfaction.
Reduction in pain
Improvement in function
For each patient in the indicated population (X-STOP Spacer = 73 patients,
Nonsurgical = 66 patients), a combined score was evaluated using device
performance, need for additional surgery for LSS, and ZCQ. To be considered an
overall clinical success, an X-STOP patient had to achieve success in all 7
criteria. 15The results show 8 times as many patients experienced clinical success
when treated with the X-STOP Spacer as compared with patients who were treated
only with nonsurgical care.
Additional assessments of the clinical trial data show that the X-STOP Spacer may:
Decreases leg pain15
Improves quality of life7
Improves pain and disability10
Decreased leg pain
A scientifically recognized statistical analysis called the Fisher exact
test was used to compare back and leg pain frequency and severity scores
between the X-STOP Spacer patient group and the nonsurgical patient group.
At 24 months, mean back and leg pain scores in the X-STOP Spacer group were
significantly less frequent and less severe while sitting, standing, or walking
as compared with the nonsurgical group.
Comparison of the mean improvement showed:
The X-STOP Spacer group had significantly greater improvement in frequency and
severity of back pain while standing and walking than the nonsurgical group.
There was no significant difference in improvement scores for back pain while
sitting between the two groups.
The X-STOP Spacer group had a significantly greater improvement in the
frequency and severity of leg pain while sitting, standing, or walking at 24
months than the nonsurgical group.
Improved quality of life
SF-36 is a patient health survey questionnaire for measuring quality of life. SF
stands for short form, and 36 refers to the fact that it has 36 questions. The
SF-36 is a widely used scientific tool in clinical studies because it provides
comparisons across a broad range of medical conditions and therapies.
Well-designed, prospective clinical studies typically include both a
condition-specific survey (such as the ZCQ) to assess the direct benefit of the
treatment, as well as a general health survey like the SF-36, to assess the
overall benefits provided by the treatment.
The results of the 2-year study demonstrated that the X-STOP Spacer is
significantly more effective at improving the quality of life in patients with
LSS than nonsurgical treatment.7
Improved pain and disability
The study described above demonstrated greater ZCQ success in patients receiving
the X-STOP Spacer.
Another commonly used and recommended tool for assessing the disabling effects
of LSS is the Oswestry Disability Index (ODI). This assessment allows patients
to measure pain intensity, personal care (washing, dressing), standing,
sleeping, lifting, sex life, sitting, social life, and walking.
A 10-point improvement in ODI is considered clinically significant. One center
of the X-STOP Spacer study measured ODI in 18 patients for 4 years. The ODI
score for X-STOP Spacer patients showed a mean improvement of 29 points.10
The authors used more strict criteria (15-point improvement) and long follow-up
(4 years) to determine success. This study showed that 78% of the X-STOP Spacer
patients had a successful outcome.
Complications that may be associated with the X-STOP Spacer procedure include,
but are not limited to, the following: Implant dislodgement (movement out of
place); implant not positioned correctly; fracture of the spinous process;
foreign body reaction (ex. allergic reaction); additional surgery, which could
include removal of the X-STOP implant; mechanical failure of the implant.
Patients treated with the X-STOP Spacer demonstrated superior outcomes to
patients treated with nonsurgical therapies, such as epidural steroid
injections, pain medications, and physical therapy.16
It is also important to note that the X-STOP Spacer provided patients with rapid
relief of symptoms.16 Most
patients who receive nonsurgical treatment do not experience sustained symptom
relief, which means that patients need to continue a regimen of epidural steroid
injections, pain medications, and physical therapy to maintain symptom relief.
If you are looking for sustained pain relief, or if you’re tired of
ongoing treatment and the side effects of pain medications, the X-STOP Spacer
may offer an effective alternative to relieve your painful symptoms.
The X-STOP Spacer provides another option for patients who are unsatisfied with
X-STOP Procedure vs. laminectomy
How does the X-STOP procedure compare to