The vertebrae are the building blocks, providing support for your head and body while the discs act as cushions, or “shock absorbers.” In addition to providing support, the spine encloses and protects a column of nerve tissues called the spinal cord. The spinal cord is surrounded by a bony channel called the spinal canal. In the lumbar spine, nerve roots pass out of the spinal canal through the intervertebral foramen, where they extend down into your back and legs. In the healthy spine, there is space between the spinal cord and the borders of the spinal canal so that the nerves are free and are not pinched. However, as we age the ligaments and bone that surround the spinal canal can thicken. This thickening results in narrowing of the spinal canal, which is called “spinal stenosis.” The spinal cord and nerve fibers that exit the spinal canal (nerve roots) become crowded and pinched due to this narrowing, resulting in pain and numbness in the back and legs.
The X-STOP device relieves the symptoms of lumbar spinal stenosis by limiting extension without any significant restriction of flexion or lateral rotation. Additionally, the X-STOP Spacer addresses many of the traditional concerns about destabilization of the spine associated with invasive decompressive procedures such as laminectomy. The X-STOP procedure does not typically require removal of bony structures or the supraspinous ligament. Preserving the supraspinous ligament has the added benefit of working along with the device’s wings to prevent lateral and posterior migration.
Orthopedics 5th year, 5th lecture (Dr. Hamid)
Spondylolisthesis is a common cause for lower-
back pain, radiculopathy, and neurogenic
claudication among the adult population.
Definition: ant. slipping of the spine.
Normal locking mechanism
Classification (Wiltse et al 1976)
F:M = 6:1
Black : White = 6:1
Hx acording to age of presentation
radiculopathy is present, the L5 nerve root
most often is affected.L4 second most
loss of lumbar lordosis,flat
Transverse loin crese
Hip flexion contractures
Fell- step-off at the listhetic level.
range of motion (ROM) usually is normal and
occasionally hypermobility may exist.
lumbar AP, lateral, and oblique views.
lateral flexion and extension,MRI
Meyerding’s system for grading:
Grade 1 is 25%,
Grade 2 is 50%,
Grade 3 is 75%,
Grade 4 is 100% displacement ,
1-day to 2-day period rest-
short course of anti-inflammatory
Modification of activity
improvement of neurologic symptoms,
improvement in the quality of life.
If attainment of these goals is unlikely,
conservative treatment should be continued.
--progressive neurologic deficit
--cauda equina syndrome.
--slip >50% and progressive
- persistent radiculopathy
-persistent and unremitting lower-back
-pain for more than 6 months,
-disabling symptom-affect work,sport
Laminectomy and Posterior Spinal Fusion (without
Decompression with Anterior and Posterior
Vertebrae provide body support
Discs act as “shock absorbers”
Vertebra protects spinal cord and nerves
Nerves have space and are not pinched
As we age, ligaments and bone can
Narrowing is called “stenosis”
Narrowing squeezes nerves in spinal
canal and nerve roots exiting spine
Result - pain & numbness in back
neurogenic claudication with intermittent pain
radiating to the thighs or legs.
Good for non-progressive minimally debilitating
Pt getting better non op
Pt getting worse Surgery
Worsening neuro sx, bowel bladder dysfunction, cauda
equina syn, debilitating pain
Predominantly leg pain
Clinical exam ∝ Imaging studies
Mild to moderate neuro deficit
No back pain (excluding spondylolisthesis)
Bilateral laminectomies for all affected levels
If discectomy performed, consider arthrodesis
Pts w/ unilateral symp
Better preserves post op stability
Difficulty in accessing
Risk for dural tear
Hinging open the lamina on one side, interpositioning
the resected spinous process
Increased size of spinal canal
Device designed to selectively impart relative flexion at
one symptomatic motion segment of the spine
Spacer only limits extension
Wings prevent side-to-side and
Preserves your supraspinous
ligament, which prevents
Treats LSS symptoms, not
Compared to traditional LSS surgery,
X-STOP benefits include:
Can be done under local anesthesia
Can be done as an outpatient procedure
No removal of the lamina (vertebral bone) or
ligaments that protect and stabilize the spine
Potential of a shorter recovery
The X-STOP Spacer