- See:
-
Herniated Disc in the Child:
-
Intervertebral Discs:
- Anatomy:
- disc herniation may vary in severity from disc protrussion to disc extrusion, to finally disc sequestration;
-
disc containment:
- w/ a contained disc herniation, the disc material herniated through the inner annulus but not the outer annulus;
- the material is therefore contained, but still can distort the path of the nerve;
- w/ a non contained herniation, the disc material penetrates both the inner and out layers of the annulus;
- the material may reside beneath the posterior longitudinal ligament or may penetrate through it, or can
be sequestered as a free fragment;
-
posterolateral disc herniation:
- protrusion is usually posterolateral into vertebral canal, where it may compress the roots of a spinal nerve;
- in the case of a posterolateral herniation, the disc will not affect nerve corresponding in number to that
intervertebral discs (that nerve emerges above the disc);
- note that each nerve emerges thru upper part of foramen and lies against body of vertebra above;
- protruded disc usually compresses next lower nerve as that nerve crosses level of disc in its path to its foramen;
- hence, protrusion of fifth lumbar disc usually affects S1 instead of L5;
- in this case, an L4-L5 disc herniation will protrude on the
L5 nerve root;
-
central (posterior) herniation:
- in the lower lumbar segments, central herniation may result in
S1 radiculopathy
- less frequently, a protruded disc above second lumbar vertebra may compress spinal cord itself or
or may result in
cauda equina syndrome;
-
far lateral disc herniation:
- may compress the nerve root above the level of the herniation (hence a L4-L5 far lateral herniation may result in a
L4 radiculopathy);
- occurs in 6-10% of all lumbar disc herniations;
- L4 nerve root is most often involved;
- patient typically have intense radicular pain (sciatic 25% and femoral 75% of the time);
- when pain is femoral, sleep in the prone position is especially painful;
- localized steroid injection:
- in the study by Weiner and Fraser (JBJS 1997), sustained relief of symptoms occured in 27 out of 30 patients;
- surgical approach may consist of a muscle splitting intertransverse approach, which gives an excellent exposure of
to the spinal nerve and dorsal root ganglion;
- references:
-
Foraminal and extraforaminal lumbar disk herniations.
- Far lateral lumbar disc herniation.
The key to the intertransverse approach.
LJ O'hara and RW Marshall.
JBJS. Vol 79-B. No 6. Nov 1997. p 943.
- The paraspinal sacrospinatus splitting approach to the lumbar spine.
LL Wiltse.
CORR. Vol 91. 1973. p 48-57.
- Foraminal injection for lateral lumbar disc herniation.
BK Weiner and RD Fraser.
JBJS. Vol 79-B. No 5. Sep 1997. p 804.
- Disc Pressure / Failure:
- intradiscal pressure is higher when sitting than when standing;
- sitting-leaning forward > sitting > standing > lying on side > supine;
- rotation combined w/ flexion are the worst positions for disc injury;
- it is elevated by bending forward, bending to side, lifting, coughing, sneezing, and straining;
- flexion, extension, and lateral bending all produce small displacements of the nucleus;
- asymmetric & cyclic loading combined w/ lateral bend, compression, and flexion are risk factors for disk herniation;
- Clinical Presentation and Diff Dx:
-
discogenic pain:
- w/ radiculopathy, there should be a predominance of leg pain over back pain;
- Exam: (neurological exam and exam of the lumbar spine)
-
straight leg raise: used to diagnose L5 and S1 radiculopathy;
- femoral stretch test: used to diagnose L4 radiculopathy;
- this test is performed by raising the leg while the patient is prone;
-
wt relief flexion test:
- MRI of Disc Herniation:
- Natural History:
- prognosis of disc herniation is generally good regardless of treatment;
- patients operated on for proven disc herniations improved more rapidly
than patients treated non operatively;
- within 4-5 years both operative and non operative treatment groups will
generally have comprable neurologic recovery;
- hence long term results are similar w/ or w/o surgery;
- of all patients who sustain acute sciatica, less than 25% will require surgery;
- despite the generally good prognosis, some patients will not recover such as
this patient who had chronic anterior compartment atrophy and a mild foot
drop (he was never treated operatively);
- Invasive Managment:
- epidural steroid injection:
- best effects are found in patients whose leg pain (or radicular symptoms) are worse than back pain;
- at least one epidural injection should probably be tried in most patients with a disc herniation since
it is often the inflammation generated from the disc which causes symptoms rather than direct
mechanical compression from disc material;
- selective nerve root injection:
- contrast radiculogram is made to ensure that the correct nerve root was being injected;
- patient was placed prone on a fluoro table;
- C arm is adjusted to allow visualization of the target area in posteroanterior, oblique, and lateral positions;
- entry site should allow visualization of the lateral edge of the pars interarticularis, transverse process, and articular facets
on the side to be injected was selected within a few centimeters lateral to the spine;
- disc space at that level is typically profiled;
- use 22-gauge spinal needle with a short bevel and consider bending the tip for easier entry;
- injection is delivered into the anterosuperior portion of the selected lumbar foramen;
- contrast solution is injected under fluoroscopic control inorder to verify proper needle placement and to
verify absence of intravascular injection;
- inject one cc of 0.25 % bupivacaine along with one cc of
betamethasone (six milligrams per cc);
-
outcomes:
- in the report by KD Riew MD et al., the authors performed a prospective study on the effect of nerve-root
injections on the need for operative treatment of lumbar radicular pain;
- 29 of the 55 patients, all of whom had initially requested operative treatment, decided
not to have the operation during the follow-up period (range, thirteen to 28 months)
after the nerve-root injections;
- of the 27 patients who had received bupivacaine alone, nine elected not to have the operation;
- of the 28 patients who had received bupivacaine and betamethasone, 20 decided not to have the operation;
- difference in the operative rates between the two groups was highly significant (p < 0.004);
- the authors concluded that selective nerve-root injections of corticosteroids are significantly more effective
than those of bupivacaine alone in obviating the need for a decompression for up to 13 to 28 months
following the injections in operative candidates;
- references:
-
The use of epidural steroids in the treatment of lumbar radicular pain. A prospective, randomized, double-blind study.
- The Effect of Nerve-Root Injections on the Need for Operative Treatment of Lumbar Radicular Pain. A Prospective, Randomized, Controlled, Double-Blind Study*
KD Riew MD et al. J Bone Joint Surg Am 82-A: 1589-93, 2000
-
percutaneous discectomy
-
diskectomy
-
post operative management:
- Complications:
-
Post Operative Diskitis:
Lumbar disc excision in children and adolescents.
The form and structure of the extruded disc.
Biochemical changes associated with the symptomatic human intervertebral disk.
Lumbar disc herniation: Controlled prospective study with 10 years of observation.
Webber H: Spine 1983;8:131-140.
Histological changes in aging lumbar intervertebral discs. Their role in protrusions and prolapses.
Histological development of intervertebral disc herniation.
Lower-extremity sensibility testing in patients with herniated lumbar intervertebral discs.
Back pain and sciatic.
JW Frymoyer.
N. Engl. J. Med. Vol 318. 1988. p 291-300.
Surgery for lumbar disc herniation: What are the choices?
DB Murrey MD and EN Hanley MD.
The journal of musculoskeletal medicine. Jan. 1999. p 39.
