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Case Study 3
Severe Low Back Pain in a 90-year-old Male
Steven Richeimer, MD
Chief, Division of Pain Medicine
Keck School of Medicine, University of Southern California
Los Angeles, CA
History
The patient, a 90-year-old male, has a long history of intermittent low back pain. For years, his pain was well-controlled after an L3-L5 laminectomy.
However, over the last 9 months, his low back pain has progressively gotten worse, and it's now severe and constant. Pain radiates into both legs. The patient reports that pain is greater in the right leg, and it is worse in the thighs compared to the lower legs. The pain has reduced the patient's activity from walking a mile every day; he now is unable to walk more than half a block. Because of this inactivity, the patient's mood and health has deteriorated.
Examination
Upon exam, the patient exhibited a stiff back and increased pain with 5º of lumbar extension. Palpation revealed tenderness over the lumbar paraspinal musculature, right side greater than left. Neurologically, the patient is intact.
Prior Treatment
Two orthopaedic spine surgeons determined the patient was not a surgical candidate. Pain medications were offered, but these were minimally helpful because the patient could not tolerate more than 2 tablets of hydrocodone 5-mg per day.
A pain specialist administered a series of 2 epidural steroid injections. Each injection provided mild relief for one week.
Images
The lumbar MRI (not shown) shows extensive degenerative disc disease, degenerative joint disease, grade 1 spondylolisthesis at L5-S1, and severe bilateral neuroforaminal stenosis at L3-L4 through L5-S1.
Plain films are consistent with these findings and flexion/extension views show the spondylolisthesis to be stable (Figure 1).
Figure 2 (below), an AP X-ray of T12-L4, shows extensive degenerative disc disease and degenerative joint disease.
A bone scan (Figure 3) reveals increased uptake bilaterally at the L4-S1 facets, worse on the right side.
Diagnosis
Lumbar degenerative disc disease, degenerative disease of the lumbar facet joints, grade 1 spondylolisthesis at L5-S1, and severe, bilateral, neuroforaminal stenosis at L3-L4 through L5-S1.
Treatment
Radiofrequency facet rhizotomies were performed bilaterally at S1 leading to dennervation of the L4-L5 and L5-S1 facet joints. At the patient's request, this was done without prior test blocks.
Outcome
Ten days after treatment, the patient noted a reduction in pain. Three weeks later, he had almost resumed his previous level of activity.
The patient experienced excellent pain relief for 10 months. When pain returned, the rhizotomies were repeated with good effect. The following year, other health problems developed. Two years after the initial rhizotomies, the patient died; however, most of this time, the patient's pain was minimal, which afforded him the ability to be active.
Case Discussion
Jason M. Highsmith, MD
Neurosurgeon
Charleston Brain and Spine
Charleston, SC
The treatment of low back pain is certainly a growing problem as our population ages. Issues such as osteoporosis, risk of pseudofusion, and surgical risks should all be considered.
Simple range of motion testing, as performed, was important in confirming the facets as the source of pain and target of treatment in this case.
Physical therapy alone in a motivated, previously active patient is unlikely to yield significant benefit. Spinal cord stimulation has significantly improved the treatment of low back pain with improved lead design, current control and electric field shaping, as well as peripheral field electrode placement. Intrathecal pumps have fallen out of favor among many physicians who cite declining reimbursement, especially in the Medicare population. One could also argue that the lifetime cost-benefit of either $20k implant is not justified in this aged patient.
For a case such as this, rhizotomies are a good option. As Dr. Richeimer points out, this option should not be overlooked. The risks of such treatment are minimal. In this case especially, the benefits to the patient were quite impressive.
Thoracic Screw Placement in Deformity: Technique Pitfalls, Complications, Results
Lawrence G. Lenke, MD
The Jerome J. Gilden Professor of Orthopedic Surgery
Co-Chief Pediatric & Adult Spinal, Scoliosis & Reconstructive Surgery
St. Louis, MO
I. Technique: Free Hand Placement of Thoracic Pedicle Screws
1. Meticulous exposure-all bony landmarks exposed
pars
facet
t.p.-out to tip
2. Begin most caudal level (neutral rotation and largest pedicle)
remember that L1and L2 pedicles are smaller diameter than T10-T12!
3. Starting point (mark with drill bit)
lower thoracic (T10-T12): down slope of bisected t.p. at junction of t.p. and lamina at same level as lateral pars
mid-thoracic (T4-T9): junction of down slope of proximal t.p. and lamina at base of superior facet, medical to lateral pars
proximal thoracic (T1-T3): junction of proximal t.p. and lamina medial to lateral pars
4. Burr small (~ 5 mm) defect in dorsal cortex and search for "pedicle blush" of bleeding cancellous bone that indicates entrance to pedicle; may not be seen in very small apical thoracic pedicles
5. Blunt slightly curved gear shift used with ~ 2 mm rounded tip
Orientation -
frontal: perpendicular to lamina (superior facet)
sagittal: cephalad (lower thoracic) orientation versus caudad (upper thoracic) orientation
axial: based on degree of rotational deformity obviously maximal at apex of scoliosis
6. Advanced gear shift first pointing slightly lateral and then once engaged at base of pedicle, turn tip 180Ú to point slightly medial to advance down pedicle into the vertebral body
7. Should advance smoothly and snug without any jump/catches. If in doubt, head more lateral! Okay to poke out lateral, no structures at risk (first 1-2 cm), then this provides orientation to more medial pedicle.
8. Probe advancement should be snug. If it's loose-probably out lateral. If cannot advance, probably aiming too medial!
9. Palpate five walls of pathway
bony floor (vertebral body) and four pedicle walls (medial, lateral, superior, inferior)
10. If completely interosseous, place TAP/smaller screw (.5 mm) less diameter than anticipated
11. Remove tap and palpate once more the five bony borders
12. Place final screw-only if completely intraosseous!
II. Confirmation of Intraosseous Screw
1. Palpation!
delicate sounding probe
palpate floor and four walls (medial, lateral, superior, inferior) entire pedicle path
palpate twice, once after the pedicle is located with the gear shift and once after it is tapped.
2. Screw orientation
concave versus convex
sagittal plane angulation
compared to adjacent screws
3. Intraoperative x-lvs
done after all screws placed but before the rod is placed
need AP and lateral films-place arms forward to see the proximal thoracic region!
4. Pedicle screw stimulation with EMG recordings
rectus abdominus (~ T7/T8-TI2)
intercostal muscles - unable to create a known tidemark for completely intraosseous screws in an animal model (Lewis, Lenke, et al, SRS 2000)
III. How To Judge If The Pedicle Is Large Enough To Instrument?
1. Plain radiographs-check pedicles in proximal thoracic, lower thoracic, and upper lumbar
Scoliosis: check all convex apical pedicles if they are at least 5 mm in diameter, the concave ones are probably large enough to place screws
Kyphosis: check x-rays of proximal thoracic and lower thoracic spine, in particular, the frontal plane of the vertebra. Often, the true AP radiograph only profiles the apical 2 or 3 segments.
It appears that there is definitely some plasticity to the pedicles such that one can often get a 1-2 mm larger screw diameter completely intraosseous than one could measure on x-ray or CT scan.
2. CT scans-not routinely done preop
need to get perpendicular to the plane of vertebra
O'Brien, Lenke et al study showed that main pedicle diameter is between 4-6 mm in thoracic scoliosis
3. MRI scan - Liljenqvist et al found the mean concave pedicle lift to be between 2.4-5.5 mm on the concavity, and between 2.3-6.0 mm on the convexity.
IV. Pitfalls
1. Pedicle not large enough (medial-lateral dimension) to accept screw
Extrapedicular screw placement (in-out-in technique)
Use hooks!
2. Unable to locate pedicle entrance
Skip that level; may return if adjacent levels provide additional information
Use hooks!
3. Violate medial wall
If pedicle is large enough, may reconstitute medial wall with a more laterally placed screw
Use hooks!
4. Screws do not line up well to accept rod
Check for aberrent screw placement
Use polyaxial screws
5. If any step problematic - Use hooks!
V. Complications/Results
1. Personal series (reviewed by Yongjung Kim, MD)
172 consecutive patients
1118 screws
screws per level
T1: 6
T2: 21
T3: 59
T4: 75
T5: 75
T6: 76
T7: 65
T8: 80
T9: 83
T10: 126
T11: 199
T12: 253
2. Screw/Diagnosis:
Pediatric Scoliosis n = 585
Pediatric Kyphosis n = 73
Adult Scoliosis n = l 19
Adult Kyphosis n = 67
Pediatric Tumor/Fx n = 15
Adult Tumor/Fx n = 259
3. No screws removed postop due to poor placement/neurologic/vascular complications, or revision surgery needed up to 9 year follow-up.
4. 400 screws placed in pediatric scoliosis evaluated by postop CT scans:
363 (90.7%) entirely intraosseous
30 (7.5%) with 0-4 mm cortical perforations (7 screws violated medial wall)
7 (1.8%) inserted between lateral pedicle and ribs
5. AIS Correction
|
Technique |
| % Thoracic Coronal Correction |
|
| psf with hooks |
1992-93 |
48% |
|
psf-hybrid
(hooks-T spine; screws-L spine) |
1994-99 |
57% |
|
psf-all screws |
2000-01 |
77% |
VI. Benefits of Thoracic Pedicle Screws in Deformity
Segmental fixation possible
Secure fixation
No implant in epidural space
Ease of rod attachments to either fixed or polyaxial screw heads
Increased cantilever possible with less risk of implant pull-off-both short and long term
In situ translation possible, best with screw at every level of correcting rod
Improves apical translation and coronal correction
Improved apical derotation Improved sagittal plane alignment
Courtesy of Spine Universe
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