Spine Flashcards
- What is the finding and what condition is this associated with?
- What level is most common?
- symptoms?
- treatment?
Facet Cyst (juxtalumbar facet cyst)
- L4-5 most common level (63%)
- Causes lateral recess stenosis, symptoms to the traversing nerve root.
- Highly associated with degenerative spondylolisthesis (82%).
- Presentation is indistinguishable from that of a herniated disk
- MRI: high signal intensity on T2-weighted image sequencing. It appears to be contiguous with the hypertrophied right facet joint, which appears to also have high signal intensity.
- Is it unstable radiographically? pre-operative flexion-extension films to evaluate for instability to include a potential fusion.
○ Yes:** laminectomy, cyst excision w/ instrumented fusion**
* Presence of instability potentiates recurrence of cyst
* Lower rate of recurrent back pain compared w/ laminectomy alone.
patients with rheumatoid arthritis and neurologic deterioration in C1-2
What is the most important preoperative imaging finding that predicts full neurologic recovery with surgical stabilization?
PADI>14mm
Boden and associates’ article presents compelling evidence that patients with rheumatoid arthritis and neurologic deterioration in C1-2 instability are more likely to achieve some improvement if the posterior atlanto-dens interval is greater than 10 mm on preoperative studies. All the patients in their series who had neurologic deterioration and a preoperative posterior atlanto-dens interval of greater than 14 mm achieved complete motor recovery.
Boden et al. “The most important predictor of the potential for neurological recovery after the operation was the preoperative posterior atlanto-odontoid interval (PADI). In patients who had paralysis due to atlanto-axial subluxation, no recovery occurred if the PADI was less than 10mm, whereas recovery of at least one neurological class always occurred when the PADI was at least 10mm. All patients who had paralysis and a PADI or diameter of the subaxial canal of 14mm had complete motor recovery after the operation.” They found no correlation with the anterior atlanto-odontoid interval (ADI) with the severity of paralysis or the potential for recovery.
Rheumatodid Cervical Spondylitis
Elective patient surgery in patient with RA gets?
Flex-ex films prior to elective surgery.
Rheumatoid Cervical Spondylitis
What are the 3 specific patterns of C spine instability in RA patients?
○ Atlantoaxial subluxation (AAS) 1st manifestation…then
○ Atlantoaxial invagination…. then
○ Subaxial subluxation
90% of patients w/ RA, when hx of long standing dz and multiple jt involvement
Rheumatoid Cervical Spondylitis
RA patient presents w/ occipital heaches, what is the cause and nerve root involved.
Occipital head aches: erosion of C1-2 compresses C2 nerve root, pain at base of skull relieved w/ manual traction
Rheumatoid Cervical Spondylitis
MRI of c-spine in RA, what is the significance of the CMA?
A cervicomedullary angle <135° is suggestive of impending neurologic deterioration with basilar invagination and is an indication for surgical decompression and stabilization.
- MRI: Cervicomedullary angle (CMA) ○ Normal 135-175 ○ In progressive superior migration of the odontoid, CMA decreases due to draping of brainstem over odontoid ○ Reduced CMA had increased association with respiratory dysfunction and sudden death
Rheumatoid Cervical Spondylitis
- Atlantoaxial Subluxation:
* what is it?
* % in RA?
* Dx/Most common findings on XR?
- 1st stage of spine involvement in RA
- 50-80% of RA patients
- Pannus formation at synovial joints b/t dens and ring of C1 resulting in destruction of transverse ligament, dens, or both
- Leads to instability b/t C1 and C2
- Dx: anterior subluxation of C1 on C2 most common finding.
Xrays to determine AADI and PADI:
- 3.5 mm on flex/ex
- PADI <14 mm more sensitive than AADI measurement for spinal cord compression in patients w/ RA. More sensitive for identifying patients at risk of neuro injury.
Surgery:
- - C1 lateral mass-C2 pedicle/pars fixation (Harms construct) using polyaxial screws
□ Lower rates of vert and C2 n. injury
□ Strongest biomechanical construct
Does not require C1-2 reduction
Rheumatoid Cervical Spondylitis: AAS
Xrays determine instability, what radiology parameters do I need to look at? Which one is more sensitive?
Xrays determine mechanical instability: c1-c2 relationship.
* AADI >9-10 mm= surgery due to risk of neurologic injury
* PADI <14 mm= surgery due to risk of neurologic injury
* 3.5 mm on flexion/ext views, though radiographic instability is common in RA and not necessarily indication for surgery.
PADI <14 mm more sensitive than AADI measurement for spinal cord compression in patients w/ RA. More sensitive for identifying patients at risk of neuro injury.
AAOS: patients with rheumatoid arthritis and neurologic deterioration in C1-2 instability are more likely to achieve some improvement if the posterior atlanto-dens interval is greater than 10 mm on preoperative studies. All the patients in their series who had neurologic deterioration and a preoperative posterior atlanto-dens interval of greater than 14 mm achieved complete motor recovery.
Rheumatoid Cervical Spondylitis
What is the surgical management for an RA patient w/ neurologic symptoms and imaging findings?
C1 lateral mass-C2 pedicle/pars fixation (Harms construct) using polyaxial screws
* Lower rates of vert and C2 n. injury
* strongest biomechanical construct
* Does not require C1-2 reduction
**C1-2 transarticular screw fixation (Magerl): less commonly used, requires C1-2 reduction, risk of vert artery and C2 nerve injury. **
Odontoidectomy: secondary procedure, anterior cord compression by pannus *often resolves after posterior spinal fusion. *
Rheumatoid Cervical Spondylitis
What is the 2nd most common manifestation of RA c- spine? What causes it?
Alantoaxial Invagination (AAI)
superior migration of odontoid, cranial settling, basilar invagination, cranial invagination
* 2nd most common c spine RA manifestation
* 40% of patients
* Tip of dens migrates above foramen magnum
Cranial migration of dens from erosion and bone loss b/t occiput and C1-2
Rheumatoid Cervical Spondylitis
Atlantoaxial Invagination:
* Most reproducible xray measure?
* Surgical Indications?
Alantoaxial Invagination (AAI)
* Cranial migration of dens from erosion and bone loss b/t occiput and C1-2
* Ranawat Line: most reproducible:
* - Surgical indications:
- Progressive cranial migration or neuro compromise O-C2 fusion
CMA <135 on MRI = impending neuro impairment
- Occipitocervical fusion: O-C2
Transoral or retropharyngeal odontoid resection for persistent brainstem compression after O-C2 fusion
Rheumatoid Cervical Spondylitis
What does the CMA indicate in Atlantoaxial Invagination?
Alantoaxial Invagination (AAI)
A cervicomedullary angle <135° is suggestive of impending neurologic deterioration with basilar invagination and is an indication for surgical decompression and stabilization
Rheumatoid Cervical Spondylitis
Subaxial Subluxation SAS:
Path?
What indicates cord compression?
Surgical indications?
What surgery?
Path: pannus in uncovertebral and facet joints resulting in soft tissue instability of facet&luscka joints.
** SAS > 4 mm or >20% of body is indicative of cord compression**
- Cervical height index (cervical body height/width) less than 2.00 approaches 100% sensitivity and specificity in predicting neurologic compromise.
Surgical indications: pain, progressive compromise, myelopathy, instability, subluxation >4 mm
> 4mm / >20% subaxial subluxation + intractable pain and neurologic symptoms > 4mm / >20% subaxial subluxation + intractable pain and neurologic symptoms
Posterior spinal fusion +/- decompression
- Fusion to most distal unstable level
- Occiput and or C1-2 jt included if AAI or AAS exists
Surgery may not reverse significant neurological deterioration, especially if tight spinal canal is present but can stabilize it.
Anterior Spinal Fusion
* Restore sagittal aligment, may increase likelihood of fusion on multilevel PSF
Cervical Myelopathy
MRI: What MRI findings will you see? What correlates to poorer prognosis?
- Effacement of CSF; spinal cord changes (myelomalacia=bright signal on T2; signal changes on T1 correlate w/ poorer prognosis following decompression)
- compression ratio of < 0.4 carries poor prognosis
CR = smallest AP diameter of cord / largest transverse diameter of cord
Cervical Myelopathy: optimal tx depends on individual and the following key considerations (4)
- # of stenotic levels
- Sag alignment of spine
- Degree of motion and desire to obtain
- Medical comorbidities
Cervical Myelopathy: combined Anterior and posterior indications
Combined anterior & posterior surgery:
* Multilevel stenosis in rigid kyphotic spine
* Multi-level anterior cervical corpectomies
* Post-laminectomy and kyphosis
Cervical Myelopathy Surgery: Laminectomy w/ posterior fusion indications and contra indications?
Indication: Multilevel compression w/ kyphosis <10 degrees. In flexible kyphotic spine, posterior decompression and fusion may be indicated if kyphosis corrected prior to instrumentation.
Contraindication: fixed kyphosis >10 degrees. Will not adequately decompress spinal cord as it is bowstringing anteriorly.
Cervical Myelopathy: Laminoplasty indications, contra-indications, technique
- multilevel cervical stenosis that preserves cervical motion. Indications include preserved cervical lordosis and lack of axial neck pain, which suggests fusion would better address arthritic facets and discs
- Maintains motion; avoids complications of in hi-risk pseudarthrosis; congenital cervical stenosis
- Contraindications: cervical kyphosis >13 degrees contra to posterior decompression; severe axial neck pain pts should be fused.
- Allows direct posterior decompression of neural elements and indirect anterior decompression allowing the cord to drift posteriorly. Need lordosis to allow for posterior drift of cord otherwise is will bowstring
- Technique: vol of conal expanded by hinged door laminoplasty followed by fusion
○ Open door: hinge created unilateral at junction of lateral mass/lanima and opening on opposite; held open by bone, suture anchors, or plates
French door: hinge B, opening at midline
Cervical Myelopathy: problem with laminectomy alone:
Rare due to risk of post-laminectomy kyphosis. 11-47% risk if laminectomy performed w/o fusion
Post-Op cervical myelopathy complications?
Complications:
- Infection: poster>anterior
- Psuedoarthrosis: 12% single level, 30% multilevel
- Post-op C5 palsy: 5%; good prognosis for function recovery, takes time.
○ Deltoid/supraspinatus abduction weakness, flexion weakness, biceps/brachialis
○ Prolonged recovery with motor grade <2
- Recurrent laryngeal nerve injury: RLN vs Left LN debate= nodifference in injury rate. Prolonged retractor placement.
- Dysphagia & alteration in speech: local steroid in retropharyngeal space prior to wound closure decreases rate of dysphagia.
Epidural hematoma: rare, emergent MRI and hematoma evacuation, MRI appearance depends on age, hyperacute <24 hrs hyperintense t2, hypoT1
Cervical Myelopathy Alogrithm: 1or 2 levels, < 10 kyphosis
Cervical Myelopathy Alogrithm: 1or 2 levels, < 10 lordotic
Cervical Myelopathy Alogrithm: 3+ levels, < 10 kyphosis
An inverted radial reflex is associated with…
- hypoactive brachioradialis reflex in combination with involuntary finger flexion.
- It is a spinal cord “release” sign and is associated with upper motor neuron pathology as seen in cervical stenosis with myelopathy.
- ** Radiculopathy is characterized by a diminished reflex but no finger flexion.** Peripheral neuropathy is not associated with any reflex change.
aaos
What is the most common physical finding in myelopathic patients
The Hoffman sign is the most common finding, occurring in 80% of myelopathic patients, and it is more common with increasing severity of the myelopathy. The prevalence of hyperreflexia has been shown to be no different from the prevalence in individuals without myelopathy. Sustained clonus and Babinski signs have been shown to occur in only one third of the patients with myelopathy.
aaos
Risk factors for airway complications with ACDF? What were not risk factors?
OR time >5hrs & exposure of 4+ vert bodies involving c4 or higher.
Not RF: pulmonary status, smoking, absence of drainage, myelopathy
aaos
patient has a cervical myelopathy with more than mm of space available for the cord; therefore, she has a reasonable chance of improved neurologic function following surgery
patient has a cervical myelopathy with more than 10 mm of space available for the cord; therefore, she has a reasonable chance of improved neurologic function following surgery. If not treated with surgery, however, her neurologic condition likely will worsen and she will die earlier than if she had surgery.
aaos
contraindication for posterior decompression (with or without fusion) for myelopathy?
Fixed kyphosis of more than 10 degrees
Although cervical instability is a contraindication to posterior decompression alone, segmental instability in the myelopathic cervical spine can be addressed with concomitant posterior fusion with instrumentation. Cervical lordosis represents the ideal scenario for posterior decompressive procedures for myelopathy (laminectomy and laminoplasty) because compression from anterior osteophytes, if present, is relieved as the spinal cord migrates posteriorly. The anteroposterior diameter of the spinal canal does not have an impact on the selection of surgical approach. Posterior unroofing-type procedures in kyphotic cervical spines, however, are ineffective because anterior impingement on the spinal cord will remain; therefore, kyphosis of more than 10 degrees is considered a contraindication for posterior decompression.
MRI scan of a 48-year-old man who reports increasing unsteadiness in his gait and hand clumsiness. Examination reveals a positive Hoffmann’s reflex bilaterally, positive clonus, and a spastic gait. Xray shows no kyphosis. Management should consist of
The patient has a congenitally small spinal canal with secondary multilevel degenerative changes causing stenosis and cord compression across multiple segments, including directly posterior to the vertebral bodies. A multilevel diskectomy may address the cord compression at the disk level, but not posterior to the bodies, and most likely would be inadequate. The patient has significant stenosis distal to C5, necessitating a more extensive surgical approach than simply C3-C5. Because the patient’s cervical lordosis is preserved, a posterior procedure such as laminoplasty or laminectomy would allow the cord to fall away from the anterior pathology and afford decompression. Cervical myelopathy does not tend to resolve, and there is a significant risk for progression; therefore, surgical management usually is recommended.
Pt has a hx of ACDF and needs revision, what do you need to consider?
When attempting a revision anterior cervical approach from the side opposite the original approach, it is important to evaluate the function of the vocal cords. If this evaluation reveals dysfunction of the vocal cord on the side of the original approach, then an approach on the contralateral side should not be attempted. Injury to the stellate ganglion, which causes a Horner’s syndrome, should not preclude an approach on the contralateral side. While the side of the symptomatology can influence the surgeon’s choice as to the side of an anterior approach, it does not preclude a certain approach. When approaching the lower cervical spine from the right side, the recurrent laryngeal nerve can cross the surgical field and should be preserved. Excessive intraoperative pressure on the esophagus can increase the incidence of dysphagia, but its incidence is no different with either approach.
Klippel-Feil syndrome
failure of segmentation of the cervical spine. The classic triad includes congenital fusion, low hairline, and a web neck.
56 y/o M w/ 2 yr hx of progressive cervical myelopathy and the MRI shown here. What is the most appropriate treatment? Why won’t other tx options work?
The cervical spine MRI scan shows spinal stenosis with multilevel spondylosis causing spinal cord compression at multiple levels. With the longstanding duration of the patient’s signs and symptoms, combined with involvement of multiple levels in the cervical spine, posterior multilevel laminectomy and fusion is the best treatment option. Two-level anterior diskectomy and fusion would address the two areas of most severe narrowing, but it would fail to decompress the other stenotic areas which also require decompression. Posterior cervical foraminotomies would only address radicular symptoms, which are not present in this patient, and would not succeed in decompression of the spinal cord. Cervical epidural injections are not indicated for myelopathy symptoms, and may in fact place this patient at risk for neurologic deterioration.
Cervical Myelopathy surgical outcomes.
- surgery should be performed as soon as possible when cervical spondylotic myelopathy has been diagnosed
- Surgical outcome is related to the patient’s age, disease course, the presence of osseous spinal stenosis, preoperative comorbidities, the preoperative spinal cord functional score, and the presence of high-signal abnormalities on T2-weighted images.
- Patients with focal high-intensity intramedullary signal changes on T2-weighted images have better clinical outcomes following surgery than do patients with demonstrable multisegmental high-intensity intramedullary signal changes on T2-weighted sequences.
Nurick Grades in cervical myelopathy and when best to operate?
** 1. signs of cord involvement, but gait remains normal.
2. there are mild gait abnormalities, not affecting the patient’s employment status. **
3. gait abnormalities prevent employment, but the patient remains able to ambulate without assistance.
4. the patient is only able to ambulate with assistance.
5. the patient is chair-bound or bedridden.
Clearly, it is desirable to operate when the patient is functioning with a Nurick grade of I or II.
What is a contraindication to laminoplasty in a patient with cervical spondylotic myelopathy?
fixed cervical kyphosis
Laminoplasty or any posterior decompressive procedure is contraindicated in patients with cervical spondylotic myelopathy and cervical kyphosis. The residual kyphotic posture of the cervical spine results in persistent spinal cord compression. The other choices are not contraindications for laminoplasty. Concomitant cervical radiculopathy can be addressed at the time of laminoplasty with a keyhole foraminotomy.
Factors associated w/ Psuedoarthrosis rates after ACDF?
Smoking and DM
* no difference in fusion rates for allograft vs autograft
* uninstrumented single level acdf higher rates of fusion than instrumented
* level of fusion does not correlate w/ fusion rates
Nonsurgical vs Surgical mgmt of LDH
Nonsurgical management is helpful for alleviating symptoms as the herniated disk resorbs.
In patients in whom nonsurgical treatment fails to improve symptoms or patients with a neurologic deficit, microdiskectomy is highly effective and is associated with better short- and long-term outcomes than nonsurgical management
??% of patients with LDH and radiculopathy experiencing spontaneous resolution of symptoms within 3 months of symptom onset
90% of patients with LDH and radiculopathy experiencing spontaneous resolution of symptoms within 3 months of symptom onset
LDH non surgical mgmt:
Acute, less than 6 weeks
1st Line: PT and NSAIDs
avoid opioids, +/- oral steroids if NSAIDs ineffective.
No support for gabapentin
Lumbar ESI: transforaminal or intralaminar approach for short term releief does not change longer term risk for surgery.
LDH surgery:
limited vs complete diskectomy?
Open microdiskectomy vs tubular?
Percutaneous endoscopic microdisk?
Post op Restrictions?
limited vs complete diskectomy: limited microdiskectomy (only herniated and free fragmented excised) is standard of care. More back pain w/ complete
Open microdiskectomy vs tubular? similiar results
Percutaneous endoscopic microdisk? no rigorous evaluation, indications unclear
Restrictions: equivalent clinical outcomes, irrespective of the length of postoperative restrictions. Do not reduce reherniations and result in slower return to regular activity.
LDH outcomes:
advantage of surgical mgmt?
revision surgery?
cauda equina, time frame for surgery?
- Surgery results in faster and more complete improvement, advantage of surgery decreased with time.
- Symptom duration >6-9 months may improve less w/ surgery.
- Revision surgery: improve, but less improvement compared to primary, higher complication rate
- Cauda equina: surgery less than 48hrs better neuro outcomes, pts have improvement in bowel, bladder and sex post op but 25-50% have residual deficit.
Trendelenbur gait results from? What level of nerve root would you see?
A Trendelenburg gait results from weakness of the gluteus medius, L5 nerve root. A paracentral disk herniation at L4-L5 most commonly results in an L5 radiculopathy and thus weakness of the gluteus medius. A paracentral herniation at L5-S1 most commonly affects the S1 nerve root. A paracentral herniation at L3-L4, a central herniation at L3-L4, and a far lateral herniation at L4-L5 all affect the L4 root.
Role of Lumbar ESI?
How does ESI compare to microdisk?
Who gets the most relief from ESI?
- LDH that fails to repsond for 6 weeks of non-op tx.
- 42-56% relief w/ ESI vs 92-98% relief w/ diskectomy. Smaller percentage of relief in the ESI group but those who get relief have similiar duration compared with surgery roughly 3 years
- extruded or sequestered herniations report the greatest and most rapid relief. Similarly, those with well-hydrated disk fragments report rapid relief of symptoms.
Pt has recurrent radicular symptoms after diskectomy, what imaging needs to be ordered and what’s the ddx
MRI with gadolinium will best identify recurrent herniated nucleus pulposus or other root compression and distinguish scar from recurrent disk.
Pt factors associated w/ recurrent radicular pain following lumbar diskectomy for sciatica? What are 2 factors associated w/ good outcomes?
Poor: large annular defect at the site of a lumbar disk herniation is associated with persistent radicular pain postoperatively.
Good:
* Large sequestered herniations
* a positive SLR preoperatively correlate with good outcomes after diskectomy.
Gaenslen’s test
Gaenslen’s test is designed to detect sacroiliac inflammation as a source of low back pain.
Beevor’s sign tests
Beevor’s sign tests the innervation of the rectus abdominus and paraspinal musculature (L1 innervation).
Lumbar stenosis symptoms? relieving factors?
Lumbar spine stenosis is a disease of exertion, with exacerbation of symptoms with prolonged standing and walking.
Relieving factors include lying down, sitting, and lumbar flexion (shopping cart sign).
Patients usually present with neurogenic claudication but also may report radicular complaints or a combination.
MRI of lumbar stenosis: what do look at? what is a positive sign?
- Look at sentral canal, lateral recess and intervertebral forament.
- Positive sign: Lack of lumbar nerve root sedimentation to dorsal the sac while performing MRI.
Axial T2-weighted MRIs of a lumbar spine at a level with no stenosis (A), a level with lateral recess stenosis (B), and a level with central canal stenosis (C). Note the trefoil shape of the canal in panel B, which is not present in panel A.
Lumbar stenosis w/ lumbar radiculopathy 2/2 synovial cyst from facet joint, outcome of surgery?
91% reported good pain relief and 82% had improvement of their motor deficits. Epstein reported a 58% to 63% incidence of good/excellent results and a 38 to 42 point improvement on the SF-36 Physical Function Scale. It was also suggested that since the presence of a synovial cyst indicates facet pathology, possible fusion should be considered in these patients, especially those with underlying spondylolisthesis.
vascular claudication symptoms then work up
Vascular claudication is a manifestation of peripheral vascular disease and presents with crampy leg pain that is exacerbated by physical exertion. The pain is easily relieved by standing still or sitting. Unlike pseudoclaudication, a forward-flexed posture and/or sitting does not improve the symptoms. Night pain is common in vascular claudication due to the elevation of the extremities and patients often report pain improvement by hanging their extremities in a dependent position. In evaluation of a patient with suspected vascular claudication, the five “P’s” of vascular insufficiency should be monitored, including pulselessness, paralysis, paresthesia, pallor, and pain. While pain and paresthesias can be common in both vascular claudication and pseudoclaudication, the presence of any of the remaining symptoms is suggestive of vascular disease.
Next step? ABI
Indication for spinal fusion in patients undergoing laminectomy for spinal stenosis?
- degenerative spndylolithesis and scoliosis
- if spine is destabilized: removal of 1 complete facet joit or iatrogenic pars fx
- fusion if very long laminectomy, though 2 level lami itself does not need fusion
On an axial CT image, which of the following dimensions is considered to be indicative of a critical amount of lumbar spinal stenosis?
- AP canal diameter less than 10 mm
- Cross-sectional area of less than 100 mm2
What permanent anatomic pelvic parameter should be measured and considered when determining the amount of lumbar lordosis correction that will be necessary to obtain sagittal balance?
Pelvic incidence
Pelvic incidence (PI) is the anatomic angle between the sacral end plate and a line connecting the center of the femoral heads. Increased pelvic incidence has been found to correlate with the incidence and severity of spondylolisthesis. Patients with increased PI require increased lumbar lordosis to restore sagittal balance. Pelvic tilt (PT) and sacral slope (SS) have also been found to correlate with lumbar lordosis; however, both PT and SS can change depending on pelvic rotation. PI is the only permanent pelvic parameter that is unaffected by pelvic rotation. Acetabular and femoral version have not been found to be associated with lumbar lordosis.
Pelvic Incidence, increased PI associated with?
- angle between sacral end plate and line connecting center of femoral heads.
- Increased pelvic incidence has been found to correlate with the incidence and severity of spondylolisthesis
- Patients with increased PI require increased lumbar lordosis to restore sagittal balance. Pelvic tilt (PT) and sacral slope (SS) have also been found to correlate with lumbar lordosis; however, both PT and SS can change depending on pelvic rotation. PI is the only permanent pelvic parameter that is unaffected by pelvic rotation. Acetabular and femoral version have not been found to be associated with lumbar lordosis.
Isthmic spondylolisthesis results from a defect in the
pars interarticularis (spondylolysis).
Spondylolysis can occur independently or in association with spondylolisthesis and often occurs at the L5-S1 level. Spondylolisthesis is the forward displacement of one vertebra with respect to the adjacent caudal vertebra.** Spondyloptosis** is defined as 100% translation of one vertebra over the next caudal vertebra
Isthmic spondylolisthesis is the most common type of spondylolisthesis in children and young adults.
It occurs in % of the population.
Isthmic spondylolisthesis is the most common type of spondylolisthesis in children and young adults.
It occurs in 5% of the population.
A 40-year-old man has intractable pain following 2 years of nonsurgical management for high-grade spondylolisthesis. What is the best surgical option?
Circumferential fusion is the preferred choice for patients undergoing revision surgery following failed posterolateral fusions for isthmic spondylolisthesis as well as for those patients having primary surgery for high-grade isthmic spondylolisthesis.
An adult patient with a grade I isthmic spondylolisthesis at L5-S1 is most likely to have weakness of the
EHL
Adult patients with isthmic spondylolisthesis most commonly have neurologic symptoms due to foraminal stenosis at the level of the spondylolisthesis. In this scenario, the patient is most likely to have weakness of the L5 myotome, which would cause weakness of the extensor hallucis longus.
What nerve root is prone to injury after reduction of spondylolisthesis? Eg reduction of grade II l5-S1 spondy
L5 nerve root is especially vulnerable and prone to injury after the reduction of spondylolisthesis in patients with mid-and high-grade isthmic spondylolisthesis
Spondylolisthesis is best classified as?
Spondylolisthesis can be classified into five types. Type I, dysplastic, occurs at the lumbosacral junction as a result of congenital abnormalities of the upper sacrum and/or the arch of L5. Type II, isthmic, refers to those involving a lesion in the pars interarticularis. Type IIA, lytic, represents fatigue fractures of the pars. Type IIB describes those with elongated, but intact pars. Type IIC describes those that are a result of an acute fracture of the pars. Type III, degenerative spondylolisthesis, results from long-standing intersegmental disease. Type IV, traumatic, refers to those resulting from fractures in regions other than the pars, such as the pedicles. Type V, pathologic, refers to spondylolisthesis resulting from generalized or local bone disease
Most common complication of surgical mgmt of degen spondylolisthesis.
A dural tear is one of the most common complications encountered during the surgical management of degenerative spondylolisthesis. The incidence of incidental durotomy in the literature ranges from 4% to 9%.
**Close in water tight fashion. **
Durotomy has no negative long-term effects on patient oucomes.
rate of revision surgery in same segment disease for degen spondylolisthesis higher for??
The rate of revision surgery in the management of same-segment disease was found to be much higher in patients with degenerative spondylolisthesis who underwent laminectomy alone compared with patients who underwent laminectomy and instrumented fusion
Risk factors for adjacent-segment disease include
Risk factors for adjacent-segment disease include higher body mass index, preoperative degenerative changes of the disk space and the facet joints, and sagittal imbalance.34 In addition, longer constructs lead to an increased incidence of adjacent-segment disease and, therefore, increased long-term revision surgery rates.35
best radiographic indicator of segmental instability at L4-L5
More than 4 mm of translation or 10 degrees of angulation compared with adjacent levels on flexion/extension radiographs. Motion segments that demonstrate more than 4 mm of translation or 10 degrees of angulation compared with adjacent motion segments on flexion-extension radiographs have excessive motion and instability
If a laminectomy for spinal stenosis is performed, which of the following is an indication for concomitant arthrodesis at that level?
Degenerative spondylolisthesis at the level of the laminectomy
A prospective randomized study of patients with degenerative spondylolisthesis and spinal stenosis by Herkowitz and Kurz showed significantly improved clinical outcomes in patients who also received a lumbar arthrodesis. Patients with a laminectomy at an adjacent level do not have improved outcomes with an arthrodesis. Minimal lumbar scoliosis does not require arthrodesis. Arthrodesis is indicated in cases where there is removal of more than 50% of the facets bilaterally but not with an associated foraminal stenosis.
Most common finding from medial breach of pedicle screw?
most common finding at exploration of an inappropriately placed pedicle screw is** displacement of the nerve**. Pedicle breach is common, ranging from 2% to 20%, but most are asymptomatic.
large series conducted by Lonstein and associates, the authors reported that displacement of the root, most often medial, was the most common finding. Laceration, contusion, or transfixion usually was not seen. Spinal fluid leakage occurs less frequently and is not expected in the minimal broach illustrated.
What factor is associated with the highest risk for in-hospital complications for patients undergoing a lumbar fusion for degenerative spondylolisthesis?
Age and having three or more comorbidities is associated with a higher rate of complications in patients undergoing a lumbar fusion for lumbar degenerative spondylolisthesis. Race, gender, and hospital size have not been found to be associated with higher complication rates.
Thoracic Stenosis:
Thoracic stenosis:
what are the 2 conditions, how do they differ?
indication for surgery?
Surgical management: posterior vs ventral?
Two distinct clinical syndromes of thoracic stenosis
- most common degenerative changes of the spine.
- Thoracic spinal cord stenosis secondary to congenital narrowing of the spinal canal is associated with a more abrupt onset of symptoms. The typical clinical manifestations of myelopathy may commence following minor or moderate trauma.
- Indications for surgery include progressive thoracic myelopathy and persistent unremitting radicular pain.
Laminectomy
* indication for thoracic laminectomy is a patient in whom imaging has demonstrated evidence of spinal canal stenosis secondary to hypertrophy of the posterior elements.
* Posterior laminectomy alone is contra-indicated because of inability to retract spinal cord and high rate of associated nuerologic injury. Should not be the primary approach when stenosis results from a significant ventral epidural osteophyte or herniated disk
- Anterior transthoracic approaches allow direct access to herniation but require going into the chest. Discetomy and hemicorpectomy performed as needed
* Posterior transpedicular, costotransversectomy, or posterolateral extracavitary approaches may allow for access to the disc herniation while avoiding the need to enter into the chest cavity; however, they require stabilization and fusion to reduce the risk of late spinal instability.
Most common place for thoracic disc herniations
Most thoracic disk herniations occur in the lower (caudal) third of the thoracic spine. This predilection may be related to the unique anatomic and biomechanical environment of that region. The 11th and 12th ribs do not join the rib cage anteriorly and do not form a true articulation with the transverse processes posteriorly. Furthermore, flexion and torsional forces tend to concentrate between T10 and L1.
Thoracic disc herniations
Symptomatic herniations of the thoracic spine are — than those of the cervical or lumbar region. They tend to occur most commonly during the —- decades of life and although they can be found at all levels, they are most common in the —–. —— has the highest rate of neurologic deterioration and is not recommended. Multiple studies have shown that herniated thoracic disks can be found at one or more levels in —% of asymptomatic individuals.
- Less common than those in C & L spine
- 3rd-5th decades of life
- more than two thirds are found at T9-T12, which is the more mobile lower third of the thoracic region.
- Posterior Laminectomy and disc excsion high rate of neurologic deterioration, posterior approaches cause manipulation of the spinal cord which should be minimized
- 40% asymptomatic
Symptomatic herniations of the thoracic spine are much less common than those of the cervical or lumbar region. They tend to occur most commonly during the third to fifth decades of life and although they can be found at all levels, they are most common in the lower third near the thoracolumbar region. Posterior laminectomy and disk excision has the highest rate of neurologic deterioration and is not recommended. Multiple studies have shown that herniated thoracic disks can be found at one or more levels in 40% of asymptomatic individuals.
Thoracic disk herniation radicular symptoms
pattern of radiating pain has been described as either following the dermatomal band around the chest or feeling to the patient as if the pain passes straight anteriorly to the chest wall.
Concern for calcified disk herniations
Occur more commonly in thoracic spine
More symptomatic
Risk of dura tear as it adheres to the dura
Higher risks of complication if managed surgically
Axial-based pain may be disk-based or facet-based and is transmitted through the ?, which innervates the facets, and the 2?, which innervates the posterior anulus.
medial branch of the dorsal root ganglia
sinuvertebral nerve
What region of the spine is most susceptible to changes in the vascular supply to the spinal cord during an anterior approach?
T8-T12
artery of Adamkiewicz, also known as the great anterior medullary artery, most typically arises off the left side of the aorta between T8 and T12. It represents the sole medullary blood supply to the thoracic spine
Conus medullaris syndrome:
most commonly accompanies injuries at the T12-L2 region.
Conus medullaris syndrome most frequently occurs as a result of trauma or with a disk herniation at L1, resulting in a lower motor neuron syndrome but with a poor prognosis for recovery of bowel and bladder dysfunction. The conus region, as the termination of the spinal cord, contains the motor cell bodies of the sacral roots. The syndrome is usually a sacral level neural injury; therefore, lower extremity weakness is uncommon.
The anulus of the disk is a fibrous layer consisting of obliquely oriented type ? collagen molecules. The softer nucleus is a remnant of the embryologic notochord and is composed of type ? collagen molecules.
anulus type I
nucleus type II
3 most common causes of LBP
three most common causes of axial LBP in adults are the intervertebral disk (40%), the lumbar facet joint (15% to 30%), and the sacroiliac joint (20%).
what is bertolotti syndrome
In some patients, a partially sacralized L5 vertebrae may form a pseudoarticulation with the sacrum (Bertolotti syndrome) and may be the source of LBP.9 The prevalence of such a finding is approximately 5%.
Desribe the pathology of DDD:
proteoglycan concentration? Water content? Pyridinoline crosslinks? Pentosidine crosslinks (marker for)? Decorin and Biglycan?
In patients with DDD, the disk undergoes a series of changes that leads to alteration of the local biology and architecture. DDD is characterized by a decline in proteoglycan concentration with loss of water content, reduced viable cells, a decrease in pyridinoline crosslinks, and an increase in pentosidine crosslinks. Pentosidine is a marker of advanced glycosylation. Decorin and biglycan are observed in relatively increased concentrations as the disk degenerates. Decreased disk height results in altered spinal biomechanics, furthering the degenerative cascade of the spinal segment.
RFN for LBP, what is it and what does it block
RFN is performed under biplanar fluoroscopic guidance. The goal of RFN is thermal coagulation of the nociceptor, the medial branches of the primary dorsal rami innervating the facet joint
adjacent segment disease lumbar spine:
biomechanical cause and risk factors
Biomechanically, fusion increases adjacent level intradiscal pressure, facet loading, and hypermobility.
Risk factors
* pedicle screw fixation,
* facet joint violation,
* sagittal malalignment,
* longer fusion length.
lumbar interbody fusion
factors associated with early post operative migration of “stand-alone’ lumbar interbody fusion
**Posterior approach, **
Postoperative migration of lumbar interbody fusion cages is a rare complication. It is most commonly seen after placement of the cages through a posterior approach, with instability of the final construct. It is not associated with the design of the cage, the type of graft used, or a resultant pseudarthrosis.
alignment of againg spine
- lumbar lordosis gradually decreases
- sagittal vertical line moves anteriorly relative to the sacrum
- Overall kyphosis in the thoracic spine gradually increases, but the coronal balance remains essentially the same unless scoliosis develops.
The primary change that takes place in the aging spine is degeneration of the lumbar disks and loss of the overall lumbar lordosis
afferent pain innervation of the L3-L4 facet joint arises from the medial branch nerve of
L2 and L3 medial branch nerves
Afferent pain fibers to the lumbar facet joints arise from the medial branch nerves originating from the next two cephalad levels. Therefore, innervation of the L3-L4 facet joint arises from the L2 and L3 medial branch nerves. This effect should be taken into account when considering a medial branch block or facet denervation. The medial branch nerve arises from the dorsal ramus of the exiting nerve root.
Anterior approach to lumbosacral juntion associated with
Retrograde ejaculation:
sequela of injury to the superior hypogastric plexus.
L5-S1 exposure
use of monopolar electrocautery should be avoided in this region. The ideal exposure starts with blunt dissection just to the medial aspect of the left common iliac vein, sweeping the prevertebral tissues toward the patient’s right side. Although erectile dysfunction can be seen after spinal surgery, it is not typically related to the surgical exposure because erectile function is regulated by parasympathetic fibers derived from the second, third, and fourth sacral segments that are deep in the pelvis and are not at risk with the anterior approach. The other choices are complications of spinal surgery but are not uniquely associated with an anterior L5-S1 exposure
Injury to the sympathetic chain during a lumbar retroperitoneal approach
Sympathectomy: ilpsilateral approach to lumbar spine, injuries sympathetic chain on that side resulting in a warm, red foot creating the appeacher that the normal cooler foot may have compromised circulation concerning for limb ischemai.
Tx: self limited, no specific treatment
What are modic changes?
Vertebral body marrow changes to the end plate seen on MRI associated with DDD.
modic changes: types and MRI findings
Modic type 1: represents bone marrow edema and inflammation
T1: low signal;
T2: high signal
T1 C+ (Gd): enhancement
Modic type 2: represents normal red haemopoietic bone marrow conversion into yellow fatty marrow as a result of marrow ischemia
T1: high signal
T2: iso to high signal
Modic type 3: represents subchondral bony sclerosis
T1: low signal
T2: low signal
What is this finding, how common is it, what kind of symptoms can happen and why?
Unilateral sacralization
* L5 Bertolotti syndrome
* 12-21% presence in population
* The altered biomechanics have been postulated to cause low back pain by placing increased stress on the adjacent cephalad disk, thus contributing to accelerated degenerative disk disease at this level. It has also been found that the neoarticulation between the enlarged transverse process and the sacrum and/or ilium may be a source of neural impingement on the exited L5 nerve root and results in radicular pain syndrome
SI joint physical exam
Degen Spondy:
L4/5 slip will cause what kind of stenosis.
- Central and lateral recess: L5 nerve root compression in lateral recess
- Foraminal: L4 nerve root compressed as vertical height is lost and slips forward.
Degen Spondy:
L4/5 slip will cause what kind of stenosis.
- Central and lateral recess: L5 nerve root compression in lateral recess
- Foraminal: L4 nerve root compressed as vertical height is lost and slips forward.
Cortical Screw vs Pedicle Screw
Cortical Screws decrease lateral exposure needed
* lower intraoperative blood loss, smaller skin incision, and decreased pain scores at 1-week post-op
* similiar fusion rates
* starting point is more medial and caudal than traditional pedicle screws, trajectory is more cephalad and lateral than traditional screw
Ankylosing Spondylitis:
Dx Criteria
Orthopedic Manifestions
Labs
Radiographs
tx:
- Bilateral Sacroillitis, +/- Uveitis, HLA B27 (90%)
(limitation of chest wall expansion < 2cm of expansion is more specific than HLA-B27 for making diagnosis) - Progressive kyphotic spine deformity, Cervical Fxs, Hip and Shoulder arthritis (hip flexion contracture
- Labs: HLA B27+, RF negative, mild ESR/CRP/WBC elevations
- Exam: limited chest wall expansion, decreased spine motion, + FABER, hip flexion contracture, kyphotic spine deformity
- enthesitis + disc space involvement
- disc space involvement, AS in cervical spine will show ossification of disc space, marginal syndesmophytes, squaring of vertebral bodies
- tx: NSAIDS, COX-2 inhibitors, and therapy
- 2nd line: infliximab, etanercept, adalimumab clinical studies show improvement.
Seronegative arthropathy: RF negative
Pt with AS, head trauma, how do you want to immobilize prior to imaging
Due to the high risk of fracture and spinal instability, the patient should be immobilized in a hard collar in his existing kyphotic position and admitted for additional imaging and observation for progressive neurological deficits, despite his normal neurological exam.
sagital imbalance
What is each angle in the image? Which angle has been found to most closely correlate with a patient’s lumbar lordosis, thoracic kyphosis, and overall sagittal alignment?
Angle A represents pelvic incidence (PI), a constant anatomic relationship between the pelvis and sacrum. Angle B represents pelvic tilt, and angle C represents sacral slope. Pelvic tilt and sacral slope can change depending on the rotation of the pelvis. Pelvic incidence has been found to directly correlate with the magnitude of lumbar lordosis and thoracic kyphosis because it determines the angle at the base of the spine (the lumbosacral junction). To obtain sagittal balance, the remainder of the spine compensates, resulting in the degree of lumbar lordosis and thoracic kyphosis to maintain an upright posture. Thus, PI must be considered in the evaluation of sagittal balance and potential reconstructive procedures. Angle D represents the T1 angle.
sagital imbalance
Flat Back Syndrome, what level should you perform the corrective osteotomy
L2 or L3, it’s away from the spinal cord, if you go too distal its hard to get fixation
The safest correction for this malalignment typically is performed away from the spinal cord in the midlumbar spine, most commonly at L2 or L3. The more distal the correction is performed, the more sagittal plane translation of the C7 plumb line with respect to the posterior sacrum. Performing the osteotomy too distally, however, makes it difficult to obtain adequate distal fixation. The clinical photograph and radiograph show an iatrogenic flatback deformity with loss of the normal lumbar lordosis.
sagital imbalance
Risk Factors for PJK? Surgical/Radiographic/Patient specific
Risk Factors and Potential Prevention Strategies for Proximal Junctional Kyphosis and Proximal Junctional Failure:
PJK is common, occurring in 10% to 40% of patients; however, PJF requiring revision surgery is much less common, ranging from 1% to 5%
sagital balance realigment targets
sagittal realignment targets have been suggested, including a SVA less than 50 mm, pelvic tilt less than 20°, lumbar lordosis = pelvic incidence ± 9°, and T1 SPI less than 0°
what do the lines represent
Central sacral vertical line (CSVL); C7 plumb line (C7PL); the horizontal distance between these two lines is the coronal vertical axis or coronal balance
Full-length spine radiographs. A, PA radiograph with a dashed line, which represents the central sacral vertical line (CSVL), and a solid line with an arrow, which represents the C7 plumb line (C7PL). The horizontal distance between these two lines is the coronal vertical axis or coronal balance. Because the C7PL is to the left of the CSVL in this patient, the coronal balance would be described as negative. B, Lateral radiograph with a dashed line, which represents the posterior sacral vertical line (PSVL) drawn from the superoposterior corner of S1, and a solid line with an arrow, which represents the C7PL. The horizontal distance between these two lines is the sagittal vertical axis (SVA) or sagittal balance. Because the C7PL is posterior to the PSVL, the SVA would be described as negative.
Type IIa Hangman’s fx
classic treatment is halo vest immobilization. Traction should be avoided in type IIa injuries because of the risk of overdistraction. A lesser form of immobilization such as a hard collar or a Minerva jacket can be used for nondisplaced (type I) fractures. Surgery generally is reserved for type III fractures (includes C2-3 facet dislocation), or extenuating circumstances such as multiple trauma or other fractures of the cervical spine that require surgical stabilization.
C1 Jefferson Burst fx on AP
classic C1 burst (Jefferson) fracture, noted that spread of the lateral masses of more than 7 mm is indicative of a transverse ligament rupture.
What condition does this patient likely suffer from?
The radiograph and sagittal T2-weighted MRI scan show multilevel degenerative changes and subaxial subluxations with anterolisthesis at C3-C4 and C4-C5 and retrolisthesis at C5-C6. In addition, there is evidence of midcervical kyphosis. Such findings are often seen in patients with rheumatoid arthritis.
TB spine: where is it commonly found?
Tuberculosis of the spine is seen in 50% to 60% of skeletal disease and is most commonly found in the lower thoracic or upper lumbar spine. Typically two or more adjacent bodies are involved as seen in this MRI scan. The disk space is narrowed but still relatively preserved as opposed to pyogenic infections (black arrow). Epidural extensions often spread from vertebrae to vertebrae (white arrow); however, the posterior elements are not frequently involved (arrowhead).
