As is the case with other areas of the spine, advances in the treatment of
the cervical spine have been made in the development of new technology such as
disc arthroplasty, in the achievement of a better understanding of surgical
morbidity, and in attempts to document outcomes of neurologic recovery. These
issues were the focus of annual meetings of both the Cervical Spine Research
Society and its European counterpart in 2005.
Additional evidence establishing the efficacy of cervical arthroplasty has
been reported. The short-term results associated with three different cervical
disc prostheses have demonstrated equivalency or slight improvement in
comparison with the results of fusion in randomized, controlled trials. The
indications for arthroplasty in the ongoing United States Food and Drug
Administration Investigational Device Exemption investigations are
single-level treatment for radiculopathy or myelopathy in patients with a
stable spine. Motion ranging from 7° to 12° has been maintained after
arthroplasty. Complications have been few; only rare neurologic complications
have been reported.
Additional benefits of arthroplasty may include diminished surgical
morbidity and earlier return to function. In one study, the reported rate of
reoperation was 2.9% after disc replacement compared with 5.4% after fusion.
Compared with patients undergoing fusion, patients undergoing arthroplasty
were reported to have a lower rate of reoperation at adjacent levels over the
same relatively short (sixteen-month) follow-up period. The most common
indication for reoperation in patients managed with disc replacement was
inadequate foraminal decompression at the index level. This indicates a need
for a meticulous wide uncal decompression when performing arthroplasty
reconstruction. Presumably because patients do not require immobilization and
are not undergoing the process of achieving fusion, return to work is much
earlier after arthroplasty. In a cohort of 976 patients, the return to work
was significantly earlier for those who underwent arthroplasty than for those
who underwent arthrodesis (thirty-two days compared with forty-one days).
Analyses of explants from patients undergoing revision have demonstrated
excellent durability of the metallic and polymeric bearing surfaces. Chemical
analysis of the polyurethane that was used as a nuclear component in one
device did not show any signs of oxidation or fragmentation of the polymer
structure. In a metallurgical study in which the surfaces of two retrieved
metal-on-metal prostheses were compared with those of similar devices that
were tested in simulators, the wear patterns were similar; however, the amount
of wear that was observed in the retrieved devices was only one-tenth of that
predicted by the simulators. The findings in this small sample indicate that
cervical devices may be significantly overdesigned for wear.
Because some patients may require reoperation, magnetic resonance imaging
with arthroplasty devices in place is important. Prostheses that contain
metals including cobalt-chromium and titanium alloys are available; these
devices have various magnetic properties that may interfere with magnetic
resonance imaging quality. Studies have shown that postoperative image quality
is totally dependent on the quality of the metal that is utilized with
Vocal cord dysfunction following anterior surgery is believed to result
from compression of the recurrent laryngeal nerve between the larynx and
retractors or from direct trauma. A prospective study documented that vocal
cord paralysis occurred in 3.2% of patients and that dysfunction occurred in
14.9%. Risk factors included a longer duration of retraction and a right-sided
approach. Deflation of the endotracheal cuff and limiting its pressure to 20
mm Hg did not prevent this complication.
The off-label use of bone morphogenetic protein-2 (BMP-2) for anterior
cervical fusion has been reported to result in a severe inflammatory reaction
and bleeding in some patients. This has led to a warning submitted by the
product's distributor. In a study from Atlanta, the rate of swelling
complications was 27.5% among patients who had been managed with BMP, compared
with only 3.6% among controls.
The use of anterior cervical plates for cervical arthrodesis has been shown
to increase postoperative dysphasia two-fold to threefold. An anatomical
investigation revealed that the esophagus lies most closely to the spine in
the midline. Laterally, however, there are 2 to 3 mm of separation, with the
right side having about 1 mm more space. Minimizing the midline plate
thickness and using the lateral potential spaces may decrease the prevalence
of postoperative dysphasia.
Cervical collars are commonly used for fracture stabilization or for
postoperative immobilization. In patients who wear an orthosis that abuts the
mandible, mastication causes the head to move into extension when the jaw
opens. Cine-fluoroscopy revealed that this motion translated to substantial
extension between the occiput and C2. Loosening the collar during mastication
eliminated this tendency.
Whiplash is a broad group of disorders resulting from a variety of
mechanisms that occur during vehicular crashes. It has been postulated that
some patients may sustain an injury of the alar and transverse ligaments.
These ligaments can be evaluated with use of specific magnetic resonance
imaging techniques. In one study, fat-suppressed T2-weighted images documented
structural abnormalities in 29.7% of patients with whiplash-associated
disorders compared with only 5.3% of controls. The importance of these
findings and how to treat these disorders is yet unknown.
Many factors have been associated with a poor outcome following whiplash. A
recent study demonstrated that abnormal scores on the SF-36 bodily pain and
role-emotional domains were strongly associated with a poor prognosis. Another
important negative predictor was a history of a Workers' Compensation or
personal injury claim and having a lawyer involved with the case. The amount
of automobile damage had no influence on outcome.
Patients with symptomatic ossification of the posterior longitudinal
ligament are often managed with posterior decompressive surgery. An important
unknown is the question of whether they will have progressive ossification
after surgery. Recent studies have shown that 75% of patients had progression.
Risk factors were a younger age (less than forty years) and disease rostral to
the C4 level.
Posterior cervical decompression for the treatment of multiple-level
myelopathy or ossification of the posterior longitudinal ligament is
theoretically effective because it allows the spinal cord to shift
posteriorly, away from ventral pathology. The degree to which this happens and
its importance were evaluated by investigators who found that wider and more
complete laminoplasties (compared with more limited approaches) were
associated with more shifting of the cord posteriorly. However, no difference
in any outcome parameter was correlated with the degree of posterior cord
translation. This brings into question how laminoplasty relieves the symptoms
of myelopathy and suggests that conventional multiple-level posterior
techniques may not be necessary.
An important neurologic dysfunction in patients with myelopathy is impaired
proprioception, presumably a major cause of gait abnormalities. This is often
thought to be a late finding that carries a poor prognosis. One investigator
measured knee proprioception and found significant differences between
patients with myelopathy and controls. Patients with myelopathy improved
rapidly within two weeks postoperatively following decompression. This
improvement persisted at two years and strongly correlated with improvement in
overall function. Surprisingly, proprioception improved more rapidly than
muscular strength did.
Biologic tools for reconstruction and regeneration continue to be one of
the most widely researched areas related to the spine today. There is a
continued effort to enhance the process of achieving spine fusion and to
eliminate the need to harvest autogenous iliac crest bone for grafting. Since
the United States Food and Drug Administration's post-marketing approval of
rhBMP-2 in 2002 and Humanitarian Device Exemption for rhBMP-7 late in 2004,
the era of using recombinant bone morphogenetic proteins to achieve spine
fusion has officially begun. Only two or three companies have access to proven
bone growth factors, and this has resulted in increased efforts by the device
industry to develop and promote motion-sparing technologies for which
intellectual property regulations are less restrictive. As well, there
continues to be increased activity in the development of lower cost bone-graft
substitutes. Finally, an increasing amount of research continues to be focused
on understanding the biology of the intervertebral disc and on developing
biologic strategies to retard or reverse degeneration.
Recombinant Osteoinductive Proteins
Data from two pilot studies evaluating rhBMP-7 (OP-1) were published in
2005. Preclinical studies and preliminary clinical data showed posterolateral
fusion success rates of 50% to 70%. A two-year follow-up pilot study
evaluating the use of OP-1 putty as an adjunct to iliac crest autogenous graft
in patients managed with posterolateral lumbar arthrodesis without
instrumentation failed to demonstrate any benefit of adding OP-1 putty to the
autogenous graft. Only five of ten patients had achievement of a solid fusion
radiographically. In contrast, a similar investigation on the use of rhBMP-2
(INFUSE; Medtronic Sofamor Danek, Memphis, Tennessee) as an adjunct to
autogenous iliac crest bone graft in patients managed with posterolateral
arthrodesis with instrumentation demonstrated a 96% rate of successful fusion.
A second study evaluated OP-1 putty as a replacement for iliac crest
autogenous graft in patients managed with posterolateral lumbar arthrodesis
without instrumentation. That study demonstrated successful fusion in 55%
(eleven) of twenty patients managed with OP-1, compared with 40% (four) of ten
patients managed with autogenous graft. While there do not seem to be major
safety issues associated with OP-1, its efficacy may not be as consistent as
that reported in association with INFUSE. At this time, it is unclear if these
differences are due to product formulation or the relative potency of BMP-2 as
compared with BMP-7 or a combination of both issues. A third osteoinductive
protein, GDF-5 (MP-52), continues to be investigated in clinical trials, and
results should be forthcoming in the next year. Another important issue is
whether these more expensive bone-graft substitutes will improve clinical
outcomes and whether improved rates of fusion will correlate with better
outcomes. The answers to these questions will take longer follow-up and will
likely also depend heavily on the preoperative diagnosis.
Two preclinical studies involving rhBMP-2 investigated the use of a
second-generation carrier consisting of a collagen sponge impregnated with 15%
hydroxyapatite and 85% tricalcium phosphate granules. This carrier performed
well in a thoracoscopic porcine interbody fusion model. In addition, this new
carrier, when wrapped with rhBMP-2 on the original absorbable collagen sponge,
allowed posterolateral lumbar fusion to be achieved with a lower dose of BMP-2
in rhesus monkeys.
Other Bone-Graft Substitutes
Given the relatively high cost of recombinant BMPs, a variety of other
bone-promoting strategies continue to be investigated. Demineralized bone
matrix (DBM), which contains natural BMPs (which retain activity if properly
processed), continues to be used in clinical practice. A common misconception
is that all DBMs are the same. Recent studies have highlighted the point that
the activity of different brands and formulations of DBMs can be highly
variable. In fact, few DBMs have been validated in large rodent models and
only one has been documented to be osteoinductive in a nonhuman primate spine
fusion model. In 2005, the Food and Drug Administration began to require 510K
approval for DBM products. This process requires documentation of at least a
minimum common level of osteoinductivity. Few clinical studies have been
performed to evaluate these materials in humans, but those that have been
performed have suggested that the more active formulations in combination with
local bone graft can perform as well as autogenous iliac crest bone graft.
The past year saw a continuation of the stream of studies demonstrating the
failure of platelet gel concentrates to increase the rate of success of spine
fusion. Despite the early heavy marketing of these platelet-based products as
containing osteoinductive growth factors, the clinical data that have been
reported by individual investigators have not supported this contention for
spinal arthrodesis. In addition, a recent study in The Journal
demonstrated that platelet-derived growth factor (PDGF) and platelet gel
concentrate inhibited the osteoinductive properties of DBM.
Another area that continues to receive attention is the use of bone marrow
as a source of progenitor cells. While it is commonly accepted that
mesenchymal progenitor cells exist in bone marrow, they are extremely rare and
usually require specific stimuli to proceed down the osteoblast lineage. Thus,
the benefit of simply adding bone marrow to other bone-graft materials is
something that has yet to be validated in a primate model. One recent study
suggested that the concentration of osteogenic progenitors is lower in the
vertebrae than in the iliac crest. Some laboratories continue to investigate
culture-expanded bone-marrow cells, a process that selects and expands the
osteoprogenitor cells. Studies involving a rabbit spine fusion model have
suggested that cultured bone-marrow cells can act as a substitute for
autogenous graft, but this requires a cell density of 100 million progenitor
cells per mL, which is substantially more than is present even in concentrated
fresh marrow aspirates. Another study demonstrated the successful use of
genetically transformed bone-marrow cells in a rat spine fusion model, but
this too required the implantation of 5 million transformed cells expressing
BMP-2 in a very small volume.
Biologic Treatments for Disc Degeneration
Disc degeneration remains an endemic reality of aging. As is the case with
most conditions, there is likely to be some genetic predisposition. At the
present time, the biologic treatment of disc degeneration remains solely in
the realm of research. Progress continues slowly to surpass a variety of
obstacles. First, the development and validation of animal models of disc
degeneration continue to be a major limitation. The vast majority of models
are disc injury models, which may or may not be relevant to natural disc
aging. Studies continue to examine the effect of mechanical forces on normal
disc nutrition and health. A third area that requires advances is the
quantitative noninvasive detection and monitoring of disc degeneration. More
sophisticated use of magnetic resonance imaging may serve this role in the
One possible approach to the treatment of disc degeneration that is
confined to the nucleus pulposus would be to revitalize the tissue by
implanting or injecting cells that have the potential to restore
functionality. These cells could be bone marrow mesenchymal cells or
culture-expanded disc cartilage cells. A recent study of rabbit intervertebral
discs demonstrated that bone mesenchymal stem cells could be transplanted and
could survive to increase proteoglycan synthesis. Another group of
investigators tested cell viability when cells were delivered with a fibrin
gel into rabbit intervertebral discs, highlighting just one of the challenges
of intradiscal cell therapy. If disc degeneration occurs because of, or
results in, nutritional compromise, then the survivability of transplanted
cells would be in question. Work continues in this area, although the
challenges remain quite substantial.
Much of what is reported in this section summarizes presentations from the
fortieth annual meeting of the Scoliosis Research Society that was held in
October 2005 in Miami, Florida.
Adolescent Spinal Deformity
There is still not universal agreement with regard to the appropriate
fixation points and implants to use for the surgical treatment of idiopathic
adolescent scoliosis. Investigators from various centers have not agreed on
the best treatment of a thoracic curve when there is a false double-major
curve pattern. Is it better to treat a thoracic curve with anterior
arthrodesis and instrumentation, with a hybrid construct, or with a pedicle
screw construct? Investigators at some centers believe that anterior treatment
is preferable, others prefer pedicle screw implants, while others believe that
a hook-wire construct accomplishes the necessary goals. It appears that the
use of thoracic pedicle screws with a convex derotation maneuver has a
lordosing effect on the thoracic spine. In many cases this is desirable, but
in other cases it may not be desirable if the patient is very hypokyphotic
preoperatively. To some extent, with posterior segmental spinal
instrumentation, a component of proximal junctional kyphosis is seen with all
of the constructs.
With regard to the anterior treatment of lumbar and thoracolumbar curves,
the use of structural or morselized rib grafts has been debated. The authors
of one study that was presented at the 2005 Scoliosis Research Society (SRS)
meeting concluded that structural grafts were better for maintaining lordosis.
That study involved the use of a single screw/single rod construct. Debate
continues with regard to whether single screw/single rod or double
screw/double rod constructs are better for the anterior treatment of
thoracolumbar and lumbar curves.
Adult Spinal Deformity
Classification is necessary in order to understand the natural history of
adult spinal deformity and to facilitate the study and treatment of adult
scoliosis and spinal deformity. Work is under way to classify adult spinal
deformity in a fashion similar to the classifications that are used for
adolescents. Classifying adult deformity is more complex. Disc degeneration
caudad to the major curve, progression of the fractional lumbosacral curve,
the existence of spinal stenosis and rotatory subluxations, coronal imbalance,
and, in particular, sagittal imbalance are more prevalent problems in the
adult population than in the adolescent population. Several investigators are
coordinating multicenter projects to accomplish this goal.
The most challenging deformity in an adult patient is one that requires a
long fusion to the sacrum. Although most investigators agree that providing
anterior structural support at L4-L5 and L5-S1 as well as bilateral iliac
fixation leads to better balance and a lower rate of pseudarthrosis, this is
not universally accepted at all centers. There is still discussion regarding
whether to stop a long construct at L5 or at the sacrum. There also is
controversy on where to stop proximally. Risk factors that can lead to the
development of proximal junctional problems and progressive kyphosis are
currently being investigated.
It is known that the surgical treatment of spinal deformity in adults is
associated with a substantially higher complication rate than is the case in
the adolescent patient population. Various complications that were discussed
at the recent SRS meeting included morbidity associated with the anterior
approach, pseudarthrosis, and sagittal thoracic decompensation after lumbar
instrumentation and fusion. When thoracolumbar, lumbar oblique, and
paramedian-type anterior approaches to the lumbar spine are compared, the
thoracoabdominal and lumbar oblique approaches appear to be associated with
greater morbidity. The most common complication is chronic pain and asymmetric
bulging of the ipsilateral abdominal body wall musculature.
Congenital Spinal Deformity
Numerous reports have indicated that hemivertebra resection in the
thoracolumbar and lumbosacral regions results in substantial correction with
relatively low morbidity. It appears that resecting the hemivertebra through a
posterior-only approach is often a reasonable alternative to combined
Numerous investigators continue to work to define the concept of
"thoracic insufficiency syndrome." The ideal treatment for a young
patient who has this condition secondary to congenital scoliosis associated
with multiple fused ribs is still evolving. Expansion thoracoplasty with use
of "titanium rib" technology is gaining acceptance over early
fusions at many centers. As is the case with the growing-rod technique, the
complication rates associated with this technique are quite high. The goal of
this technique is to favorably impact pulmonary mechanics and growth.
Follow-up to adulthood will be required to determine the efficacy of this
There are many causes of scoliosis in children under the age of ten years
other than a congenital etiology. These include connective-tissue disorders,
inherited syndromes, and idiopathic infantile and juvenile scoliosis. The
preferred initial treatment in most cases is bracing. In cases in which the
curve progresses in spite of bracing, most investigators believe that it is
beneficial to avoid arthrodesis at least until the age of eight to ten years.
In these cases, instrumentation without fusion is usually desired.
"Fusionless surgery" submits the patient and family to a prolonged
and recurring surgical plan that is associated with a unique list of
complications. It appears that the best results are achieved in association
with a dual growing-rod construct with two-vertebra fixation at each end and
scheduled lengthenings at six-month intervals.
Etiology of Idiopathic Adolescent Scoliosis
A small number of centers continue to study the genetics of familial
idiopathic scoliosis and kyphoscoliosis. This work is heavily supported by the
Scoliosis Research Society. Investigation is quite complex because of the
substantial heterogeneity of these disorders. As one researcher stated at the
recent SRS meeting, "Ultimately the independent association of genetic
loci and these disorders will enhance the ability to elucidate prognosis,
counsel patients, and guide therapeutic plans."
There is a trend toward treating Scheuermann kyphosis with a posterior-only
surgical construct. This usually requires posterior column shortening through
aggressive facetectomies or osteotomies in conjunction with pedicle screw
implants. Although the follow-up is still relatively short, it appears that an
acceptable rate of fusion is achieved. However, a substantial number of
patients with Scheuermann kyphosis still have development of proximal and
distal junctional kyphosis. The complication rate associated with the surgical
treatment of adolescent Scheuermann kyphosis is higher than that associated
with adolescent idiopathic scoliosis. Not surprisingly, the complication rate
is even higher in adult patients than in adolescent patients with Scheuermann
Many investigators at the SRS meeting reported on the treatment of
neuromuscular scoliosis, including the surgical treatment of both spastic and
flaccid deformities. While surgical techniques varied, most investigators
recommended a long instrumented fusion to the sacrum and some form of pelvic
fixation. Although the complication rate was fairly high after follow-up
periods ranging from two to ten years, most authors believed that patients did
benefit from these procedures.
With respect to the surgical treatment of spondylolisthesis, there remains
considerable controversy with regard to when to use implants (pedicle screws),
when to perform a combined fusion as opposed to only a posterior fusion, and
when to decompress and when to reduce a high-grade spondylolisthesis in
pediatric patients. Seemingly all patients do well in the short run if a solid
fusion is achieved without major systemic or neurologic complications.
Much of the research over the last year focused on the psychological,
social, and medical challenges facing patients with spinal cord injury. This
section provides an overview of the oral presentations that were delivered at
the meeting of the American Spinal Injury Association that was held in May
2005 in Dallas, Texas.
The psychosocial impact of spinal cord injury appears to be especially
strong on pediatric and adolescent patients. A cross-sectional study assessing
the impact on quality of life demonstrated that adolescent patients with
spinal cord injury had significantly lower quality-of-life scores than
age-matched able-bodied individuals. Additionally, adolescents with a spinal
cord injury had a lower quality of life as compared with age-matched obese
children. Another study indicated that suicide was as frequent a cause of
death as pulmonary disease among adolescent patients who had a spinal cord
Pressure ulcers remain a common problem among young patients with a spinal
cord injury. Patients at higher risk typically have a complete spinal cord
injury, have a history of substance abuse, and have lower mental function
scores. Pressure ulcers, although significantly impacting quality of life,
have been shown not to preclude employment, independent living, or life
Nonetheless, patients with a spinal cord injury may become active and
productive members of society. An analysis of >20,000 patients demonstrated
a significantly higher likelihood of employment in association with certain
factors, including younger age, white race, higher education level, marriage,
a nonviolent cause of injury, ASIA grade-C or D paraparesis, a longer time
after the injury, a higher employment rate in the general population, lower
Social Security Disability benefits, and the number of calendar years since
the passage of the Americans With Disabilities Act. The calculated work-life
expectancy of individuals varied according to level of education;
specifically, it was normal among individuals with professional degrees and
was substantially reduced among those with less than a college-level
Some of the predictors of neurologic recovery have become clarified.
Although age, gender, the mechanism of injury, and the level of injury are not
independently predictive, other factors are. In general, less severe injury
patterns are predictive of improved outcomes. Sparing of sensation to pin
prick, intact bladder function, spinal shock for less than twenty-four hours,
and the early reappearance of deep tendon reflexes are positive factors.
Negative factors include a complete lesion, spinal shock for more than one
week, and flexor spasms occurring within three weeks after the injury.
Overall, the speed of neurologic recovery within the first three weeks has
been shown to be the single strongest predictive factor for overall
Although the potential for pulmonary and thromboembolic disease among
patients with a spinal cord injury has been well publicized, both male and
female patients with a spinal cord injury are at substantial risk for
cardiovascular disease. Abnormal lipid profiles, hyperglycemia, and the
development of time-dependent carotid artery disease have been documented in
otherwise young patients. The use of niacin may be beneficial for decreasing
the cardiovascular risk among patients with chronic tetraplegia.
Advances in rehabilitation following a spinal cord injury have shown
lasting effects. The use of body-weight-supported treadmill training has been
effectively used to restore independent movement in patients with incomplete
motor paralysis. Impressively, the individuals maintained independent walking
ability well beyond the completion of treatment.
The use of new technologies also may improve quality of life by allowing
patients, especially those who are most severely injured, to interact with
their environment by simply thinking the correct thoughts. The BrainGate
neural interface system attempts to translate cortical signals into computer
actions through a sensor that is placed on the cerebral motor cortex. It has
been used successfully by patients to move a computer cursor with neural
activity. The ability to control computer function by means of mental function
alone could redefine the "disabilities" associated with spinal
Novel developments related to the treatment of degenerative lumbar spinal
disorders have occurred at a rapid pace. It is hoped that these new implants
and techniques will allow investigators to address one of the most problematic
areas of the spine. Much of the information that is described here was
presented at the annual meeting of the International Society for the Study of
the Lumbar Spine (ISSLS) that was held in May 2005 in New York, NY.
Lumbar Disc Arthroplasty
Many recent studies have evaluated motion-preservation devices and their
viability as a means of treating lumbar spinal disorders, specifically with
regard to their potential to reduce the risk of adjacent-segment degeneration.
Such devices are a potentially exciting method for the treatment of lumbar
spinal disorders, and a number of studies evaluated their efficacy and the
results of various prostheses.
One prospective study evaluated artificial disc replacement as an
alternative to spinal fusion in the lumbar spine. That study, which included
twenty consecutive patients with at least two years of follow-up, demonstrated
good preservation of lumbar motion, good outcomes, and the absence of
Another study examined the use of disc arthroplasty for the treatment of
adjacent-segment degeneration in twenty consecutive patients who had had a
previous fusion. There was significant improvement in the pain scores as well
as in patient satisfaction scores in the postoperative period. On the basis of
the early success rate of 86% after one year of follow-up, the authors
concluded that lumbar disc arthroplasty was efficacious for the treatment of
symptomatic adjacent lumbar discogenic low-back pain following a previous
In another prospective study, sixty-four consecutive patients who had been
managed with a metal-on-metal disc replacement were evaluated after at least
two years of follow-up. That study demonstrated significant improvement in the
Oswestry Disability Index (p < 0.0001) and in visual analog scores (p <
0.0001). Outcomes analysis with use of the SF-36 instrument showed 85%
improvement in the physical scores and 43% improvement in the mental scores.
Complications related to the anterior approach included ureteral tearing,
common iliac vein tearing, and posterior wall fracture. There were no
In another study, which included a total of 105 patients with a minimum of
twelve months of follow-up, two-level total disc replacements were compared
with single-level replacements. The two-level disc replacement group had
significant improvements in terms of pain and functional scores and had
outcomes similar to those in the single-level group, confirming the efficacy
of performing disc arthroplasty at two adjacent levels.
Lumbar Fusion Compared with Arthroplasty
A review comparing the outcomes of disc arthroplasty with those of lumbar
fusion identified a common theme in the disc-replacement studies as well as in
the fusion studies involving the use of recombinant BMP-2. Both groups did
better than did their respective control groups, in which the treatment
involved fusion with use of autogenous iliac crest bone graft. The review also
demonstrated that the groups treated with spinal fusion with recombinant BMP-2
and the groups treated with disc arthroplasty had similar improvement in terms
of both the Oswestry Disability Index and pain at the time of the two-year
follow-up. The investigators suggested that additional studies should be
performed in which fusion in the control group is accomplished with rhBMP-2
instead of autogenous iliac crest bone graft in order to allow for more
Complications of Disc Arthroplasty
One of the main concerns associated with disc replacement is the challenge
of revising failed implants. One study evaluated the complications that
occurred in a group of 347 patients undergoing lumbar disc arthroplasty and a
control group of ninety-nine patients undergoing lumbar fusion. The rate of
reoperation was 7.8% (twenty-seven patients) in the study group, compared with
10.1% (ten patients) in the control group. Common reasons and complaints that
necessitated reoperation in the disc-replacement group were persistent pain,
pseudoradicular symptoms, mechanical low-back pain, and lower extremity
cramping. Fifteen patients underwent repeated anterior approaches with removal
of the prosthesis. Five of these fifteen patients had a revision with another
artificial disc, typically one of a smaller size. The other ten patients had a
successful conversion to a fusion.
Lumbar Disc Herniation
There has been little research assessing the long-term outcome of lumbar
discectomy. It is thought that patients who have had lumbar discectomy may be
more prone to further degeneration at the level of surgery in the
postoperative period and may eventually require a fusion.
One study evaluated the five-year results of lumbar discectomy in
fifty-three patients. This multicenter, retrospective study demonstrated
significant improvements, both mentally and physically, with a low level of
pain and functional disability. In general, the patients were quite satisfied
with the results of surgery. Although additional study and longer follow-up
are needed, lumbar discectomy appeared to have excellent results, with a low
level of symptomatic discogenic back pain, within the five-year follow-up
period in this outcome study.
Another study analyzed the results of total disc replacement in fifteen
patients who had discogenic low-back pain following a previous discectomy.
After a minimum duration of follow-up of two years, these patients had
significant improvement in outcomes. The investigators concluded that total
disc replacement is a viable option for the treatment of discogenic back pain
following a previous discectomy.
Interspinous Process Distraction for Spinal Stenosis
Lumbar decompression with the placement of a distracting device between the
spinous processes has been shown to be effective for the treatment of spinal
stenosis and neurogenic claudication. In one study, data were presented on a
series of sixty-one patients who had neurogenic claudication secondary to
degenerative spondylolisthesis at one or two levels. These patients were part
of a Food and Drug Administration-approved prospective, randomized,
multicenter study in which patients who were managed with the X STOP device
(St. Francis Medical Technologies, Alameda, California) were compared with
those who were managed conservatively with epidural steroids. After two years
of follow-up, there were significant improvements in the group that had been
managed with the interspinous process decompression device as compared with
the control group. The patient-satisfaction scores and outcome-analysis scores
also improved significantly in the operative group. The authors of the study
concluded that interspinous process decompression with use of this device was
more effective than conservative treatment for patients with grade-I
A similar study examined 260 consecutive patients who were managed with a
similar type of device, the Wallis interspinous process device. The authors
noted significant improvement in outcomes categories when the postoperative
findings were compared with the preoperative findings.
Another study evaluated the results associated with the X STOP device in a
group of 100 patients who were managed with either a one-level procedure
(sixty-four patients) or a two-level procedure (thirty-six patients). After a
minimum of two years of follow-up, there were no significant differences
between the two groups, confirming success at two levels as well as one.
The editorial staff of The Journal reviewed a large number of
recently published research studies related to the musculoskeletal system that
received a Level of Evidence grade of 1. Over 100 medical journals were
reviewed to identify these articles, which all have high-quality study design.
In addition to articles published previously in this journal or cited already
in this Update, thirty-one level-1 articles were identified that were relevant
to spine surgery. A list of those titles is appended to this review after the
standard bibliography. We have provided a brief commentary about each of the
articles to help guide your further reading, in an evidence-based fashion, in
this subspecialty area.
The forty-first annual meeting of the Scoliosis Research Society (SRS) will
be held on September 13 through 16, 2006, at the Monterey Conference Center in
Monterey, California. It will be preceded by a one-day course entitled
"Modern Techniques in Spine Deformity Surgery: Is the Evidence as Good
as the Theory?" to be held on September 13, 2006. Web site:
The twenty-first annual meeting of the North American Spine Society (NASS)
will be held on September 26 through 30, 2006, at the Sheraton Seattle Hotel
and Towers in Seattle, Washington. There will be a number of precourses on
September 25, 2006. Web site:
The thirty-fourth annual meeting of the Cervical Spine Research Society
(CSRS) will be held on November 30 through December 2, 2006, at The Breakers
in Palm Beach, Florida. Web site:
The Federation of Spine Associations will present the spine program on
Specialty Day at the annual meeting of the American Academy of Orthopaedic
Surgeons, to be held on February 17, 2007, in San Diego, California. Web site:
The annual meeting of the International Society for the Study of the Lumbar
Spine (ISSLS) will be held on May 30 through June 2, 2007, in Beijing, China.
The thirty-third annual meeting of the American Spinal Injury Association
(ASIA) will be held on May 30 through June 2, 2007, in Tampa Bay, Florida. Web
The fourteenth annual International Meeting on Advanced Spine Techniques
(IMAST) will be held on July 11 through 14, 2007, at The Atlantis Hotel in
Paradise Island, Bahamas. Web site:
Blumenthal S, McAfee PC, Guyer RD, Hochschuler SH,
Geisler FH, Holt RT, Garcia R Jr, Regan JJ, Ohnmeiss DD. A
prospective, randomized, multicenter Food and Drug Administration
investigational device exemptions study of lumbar total disc replacement with
the CHARITE artificial disc versus lumbar fusion: part I: evaluation of
Part I was a prospective, randomized, multicenter study that demonstrated
that the clinical outcome following lumbar disc replacement with the
CHARITÉ device was at least equivalent to the clinical outcome
following anterior lumbar interbody fusion. In fact, by most measures, the
CHARITÉ group performed better than the fusion group. The control group
may not have been entirely appropriate in that these patients underwent a more
invasive surgical procedure in which autologous bone was harvested from the
iliac crest. Otherwise, the study was well done and the conclusion was
McAfee PC, Cunningham B, Holsapple G, Adams K,
Blumenthal S, Guyer RD, Dmietriev A, Maxwell JH, Regan JJ, Isaza J. A
prospective, randomized, multicenter Food and Drug Administration
investigational device exemption study of lumbar total disc replacement with
the CHARITE artificial disc ver-sus lumbar fusion: part II: evaluation of
radiographic outcomes and correlation of surgical technique accuracy with
The authors of this study attempted to correlate clinical outcomes with
radiographic results in patients managed with the CHARITÉ device and
those managed with anterior interbody fusion and threaded cages. The
CHARITÉ group demonstrated better restoration of disc-space height and
significantly less subsidence than did the anterior interbody fusion group.
The CHARITÉ group maintained the range of flexion-extension twenty-four
months following surgery. It appears that disc replacement has advantages over
fusion with threaded cages.
Burkus JK, Sandhu HS, Gornet MF, Longley
MC. Use of rhBMP-2 in combination with structural cortical
allografts: clinical and radiographic outcomes in anterior lumbar spinal
J Bone Joint Surg Am.
This prospective, randomized trial investigated the use of rhBMP-2 inside a
cortical allograft bone dowel in the anterior lumbar interbody arthrodesis
setting. Two years after surgery, the rate of successful fusion in the BMP-2
group (98.5%) was superior to that in the autogenous bone graft control group
(76.1%). Clinical outcomes were also superior in the BMP-2 group. Transient
peri-allograft bone resorption was noted in some patients. Clearly, BMP-2 is
emerging as a very useful drug to facilitate spinal fusion. (BMP-2 is a drug,
but it is considered to be a device by the Food and Drug Administration.)
Childs JD, Fritz JM, Flynn TW, Irrgang JJ, Johnson
KK, Majkowski GR, Delitto A. A clinical prediction rule to identify
patients with low back pain most likely to benefit from spinal manipulation: a
Ann Intern Med.2004;141:920-8.
The purpose of this randomized study was to determine if a prediction rule
is effective for identifying patients who would benefit from spinal
manipulation. Although the prediction rule was effective, the conclusions of
the study were limited because of the large number of patients who were lost
to follow-up and the inadequate power for many of the outcome variables.
Dziurzynski K, Anderson PA, Bean DB, Choi J,
Leverson GE, Marin RL, Resnick DK. A blinded assessment of
radiographic criteria for atlanto-occipital dislocation.
This study pointed out the difficulty of identifying atlanto-occipital
dislocation in trauma patients. Various radiographic parameters exist, but
identifying the landmarks is quite complex. The authors analyzed five methods
in a study of 104 patients and concluded that a two-dimensional reconstructive
computed tomography scan is the best radiographic tool for identifying
atlanto-occipital dislocation. The authors concluded that computed tomography
scans of the cervical spine are warranted for all trauma patients with a
suspected cervical spine injury in order to rule out atlanto-occipital
dislocation. This should be considered a landmark article.
Fairbank J, Frost H, Wilson-MacDonald J, Yu LM,
Barker K, Collins R; Spine Stabilisation Trial Group. Randomised
controlled trial to compare surgical stabilisation of the lumbar spine with an
intensive rehabilitation programme for patients with chronic low back pain:
the MRC spine stabilisation trial.
Erratum in: BMJ. 2005;330:1485.
This prospective, randomized trial investigated the benefit of lumbar
fusion compared with that of intensive rehabilitation for patients with
chronic low-back pain who were considered to be candidates for spinal
arthrodesis. No clear evidence emerged that primary spinal arthrodesis was any
more beneficial than intensive rehabilitation as measured with use of the
Oswestry Disability Index.
Freeman BJ, Fraser RD, Cain CM, Hall DJ, Chapple
DC. A randomized, double-blind, controlled trial: intradiscal
electrothermal therapy versus placebo for the treatment of chronic discogenic
low back pain.
This prospective, double-blind trial failed to demonstrate any significant
benefit of intradiscal electrothermal therapy over placebo.
Friedrich M, Gittler G, Arendasy M, Friedrich
KM. Long-term effect of a combined exercise and motivational program
on the level of disability of patients with chronic low back pain.
This was a prospective, randomized, controlled trial of ninety-three
patients who were randomly assigned to a control group (managed with standard
exercise therapy) or a motivational group (managed with a combined exercise
program and a motivational program). Follow-up assessments were performed at
varying time-points up to five years. The combined exercise and motivational
program was superior to the exercise-alone program, and patients in the
motivational group had significant improvements in terms of disability, pain
intensity, and working ability. It appears that the concept of a motivational
program has promise.
Furlan AD, van Tulder MW, Cherkin DC, Tsukayama H,
Lao L, Koes BW, Berman BM. Acupuncture and dry-needling for low back
Cochrane Database Syst Rev.2005;1:CD001351.
This meta-analysis of thirty-five randomized, controlled studies evaluated
the efficacy of acupuncture and dry-needling. A small short-term effect in
terms of pain reduction and functional improvement was noted when acupuncture
was compared with sham treatment or no treatment. Dry-needling may be useful
only as an adjunct to other therapies. No evidence is available with regard to
whether the effect is sustained in the long term.
Gibson JN, Waddell G. Surgery for
degenerative lumbar spondylosis.
Cochrane Database Syst
This systematic review evaluated randomized or quasi-randomized studies of
the outcome of surgical treatment of lumbar degenerative conditions including
spondylosis, degenerative disc disease, instability, spinal stenosis, and/or
degenerative spondylolisthesis. The authors noted the reporting of a variety
of outcomes, most of which had inadequate follow-up or poorly reported
specific outcome measures. There appeared to be limited evidence to support
certain aspects of surgical intervention. The authors recommended additional
well-designed controlled, prospective studies to evaluate the effectiveness of
surgical intervention in specific subgroups of patients with lumbar
degenerative spinal disease.
Gun RT, Osti OL, O'Riordan A, Mpelasoka F,
Eckerwall CG, Smyth JF. Risk factors for prolonged disability after
whiplash injury: a prospective study.
This prospective study of 135 patients with whiplash injury demonstrated
that the SF-36 bodily pain and role-emotional scales are useful means of
identifying patients who are at prolonged risk of disability.
Haas M, Groupp E, Muench J, Kraemer D,
Brummel-Smith K, Sharma R, Ganger B, Attwood M, Fairweather A.
Chronic disease self-management program for low back pain in the elderly.
J Manipulative Physiol Ther.2005;28:228-37.
In this prospective, parallel-groups, randomized, controlled trial of 109
senior patients with an age of more than sixty years, patients who were
managed with a six-week program for the treatment of chronic back pain (with
one session per week) were compared with patients who had no treatment. At the
six-month follow-up, there was no difference between the groups in terms of
reduction in pain, general health, self-efficacy, and selfcare attitudes. A
benefit was suggested for emotional well-being, fatigue, functional
disability, and days with disability. This study shows that perhaps some
directed self-management advice may help with the management of aspects of
Haig AJ, Tong HC, Yamakawa KS, Quint DJ, Hoff JT,
Choido A, Miner JA, Choksi VR, Geisser ME. The sensitivity and
specificity of electrodiagnostic testing for the clinical syndrome of lumbar
This prospective diagnostic trial of 150 subjects suggested that
electrodiagnostic testing may be useful for the evaluation of spinal stenosis.
The authors concluded that electrodiagnostic testing could differentiate
patients with spinal stenosis from those with only lumbar back pain and from
asymptomatic subjects. Furthermore, the authors claimed that the testing could
detect common neuromuscular diseases that could mimic spinal stenosis. How
this fits in with magnetic resonance imaging and treadmill testing will
require further investigation.
Hayden JA, van Tulder MW, Malmivaara AV, Koes
BW. Meta-analysis: exercise therapy for nonspecific low back pain.
Ann Intern Med.
This was a meta-analysis of sixty-one randomized, controlled trials
evaluating the outcomes of exercise therapy in adults with nonspecific
low-back pain. Exercise therapy appeared to be slightly effective for
decreasing pain and improving function in adults with chronic low-back pain.
For patients with subacute low-back pain, there was some evidence that a
graded activity program improved absenteeism outcomes. For those with acute
low-back pain, exercise therapy was as effective as either no treatment or
other conservative treatments. The benefits of exercise therapy may be more
dramatic in patients with chronic and subacute low-back pain than in those
with acute low-back pain.
Hayden JA, van Tulder MW, Tomlinson G.
Systematic review: strategies for using exercise therapy to improve outcomes
in chronic low back pain.
Ann Intern Med.2005;142:776-85.
This was a systematic review of forty-three randomized, controlled trials
of exercise therapy for the treatment of chronic low-back pain. There were
seventy-two exercise treatment groups and thirty-one comparison groups.
Improvements in terms of pain and function were noted in association with
specific exercise interventions that were delivered in an organized fashion
with the addition of a variety of conservative modalities such as
anti-inflammatory medications and advice. The two most important factors that
were noted to decrease pain and to improve function appeared to be stretching
and strengthening exercises, respectively.
Heymans MW, van Tulder MW, Esmail R, Bombardier C,
Koes BW. Back schools for nonspecific low back pain: a systematic
review within the frame-work of the Cochrane Collaboration Back Review Group.
This systematic review demonstrated moderate evidence suggesting that back
schools, in an occupational setting, reduced pain and improved function and
return-to-work status as compared with the findings for exercise,
manipulation, myofascial therapy, advice, placebo, and waiting list controls.
The overall quality of studies was low, but the evidence suggested that back
schools in an occupational setting may reduce pain and improve function for
patients with chronic and recurrent low-back pain.
Jackson AP, Haak MH, Khan N, Meyer PR.
Cervical spine injuries in the elderly: acute postoperative mortality.
A retrospective review of 458 patients who had a cervical spine injury and
were managed at a single tertiary referral center was performed to evaluate
postoperative mortality. Patients were divided into two groups (older than
sixty-five years or younger than sixty-five years). During the initial
hospitalization, the mortality rate was 12.2% for elderly patients and 2.3%
for patients under the age of sixty-five years. All elderly patients without a
neurologic deficit survived the perioperative period. The authors concluded
that patients with a cervical spine injury who are more than sixty-five years
old can expect an 87.8% rate of postoperative survival following surgical
Jellema P, van der Windt DA, van der Horst HE,
Twisk JW, Stalman WA, Bouter LM. Should treatment of (sub)acute low
back pain be aimed at psychosocial prognostic factors? Cluster randomised
clinical trial in general practice.
The purpose of this study was to assess and to modify psychosocial
prognostic factors regarding low-back pain in general primary-care practices.
A group of Dutch general practitioners used the Roland-Morris disability
questionnaire as their measure. This was an interesting and novel concept, but
unfortunately the study did not provide any evidence that strategizing
treatment according to psychosocial prognostic factors altered the outcome in
patients with low-back pain.
Khadilkar A, Milne S, Brosseau L, Wells G, Tugwell
P, Robinson V, Shea B, Saginur M. Transcutaneous electrical nerve
stimulation for the treatment of chronic low back pain: a systematic review.
The purpose of this systematic review of the literature was to determine
the effectiveness of transcutaneous electrical nerve stimulation for the
treatment of chronic low-back pain. There were two randomized, controlled
trials involving a total of 175 patients that differed significantly in terms
of their methodology and application of this treatment. One trial demonstrated
significantly greater relief of pain with the use of the transcutaneous
electrical nerve stimulation whereas the other showed no difference. The
evidence regarding the efficacy of transcutaneous electrical nerve stimulation
as an isolated intervention for the treatment of low-back pain is limited and
Kroeling P, Gross A, Houghton PE; Cervical Overview
Group. Electrotherapy for neck disorders.
Database Syst Rev.2005;2:CD004251.
The authors performed a systemic review of randomized or controlled
clinical trials with quasi-randomization to evaluate the effectiveness of
electrotherapy in the treatment of mechanical neck disorder or acute whiplash.
The authors commented on the low quality of the various trials and could find
no definitive evidence supporting pulsed electromagnetic field therapy,
iontophoresis, electronic muscle stimulation, transcutaneous electrical nerve
stimulation, permanent magnets, or galvanic current (direct or pulse) for the
treatment of mechanical neck disorders or acute whiplash.
Long A, Donelson R, Fung T. Does it matter
which exercise? A randomized control trial of exercise for low back pain.
Direction-based physical therapy matches the patient's perception that
flexion or extension causes less pain. For example, patients who have less
pain in extension are managed with extension exercises. In a randomized,
controlled study of patients with back pain, directional therapy that was
matched to the physical therapy prescription was associated with significantly
improved outcomes whereas nonmatched therapy was associated with significantly
poorer outcomes. The authors concluded that mechanical assessment and
direction-based therapy should be considered when ordering physical therapy
for the treatment of chronic low-back pain. It will be interesting to see if
other centers can perform a similar study with the same results and
Ng L, Chaudhary N, Sell P. The efficacy of
corticosteroids in periradicular infiltration for chronic radicular pain: a
randomized, double-blind, controlled trial.
This randomized, double-blind, controlled study evaluated the efficacy of
periradicular infiltration of corticosteroids versus bupivacaine for the
treatment of chronic radicular pain. Eighty-six patients were randomized to
either a single injection of methylprednisone and bupivacaine or bupivacaine
alone. After three months of follow-up, no significant difference in any
outcome measure was noted between the groups. The chronicity of symptoms was
correlated adversely with negative changes in the Oswestry Disability Index.
Corticosteroids appeared to add no significant additional benefit over an
analgesic alone in reducing chronic radicular pain.
Ostelo RW, van Tulder MW, Vlaeyen JW, Linton SJ,
Morley SJ, Assendelft WJ. Behavioural treatment for chronic low-back
Cochrane Database Syst Rev.2005;1:CD002014.
This systematic review compared the results for patients managed with three
behavioral treatment approaches (operant, cognitive, and progressive
relaxation [biofeedback]) with those for surgical wait-list controls. On the
basis of three studies, the authors concluded that combined progressive
relaxation-cognitive therapy and progressive relaxation therapy only are more
effective than no treatment in the short term. No evidence is available as to
whether the effect is sustained in the long term.
Peloso P, Gross A, Haines T, Trinh K, Goldsmith CH,
Aker P; Cervical Overview Group. Medicinal and injection therapies
for mechanical neck disorders.
Cochrane Database Syst
This was a literature review of thirty-two trials that examined the effects
of oral nonsteroidal anti-inflammatory drugs, psychotropic agents, steroid
injections, and anesthetic agents for the treatment of mechanical neck pain.
The authors of this review concluded that intramuscular injections of
anesthetics and intravenous injections of steroids were effective for the
treatment of mechanical neck disorders. There was limited evidence supporting
epidural injections, oral psychotropic medications, and nonsteroidal
anti-inflammatory drugs. There was moderate evidence that botulinum toxin
(Botox A) intramuscular injections were no better than saline solution. The
evidence appears to support the use of more nontraditional approaches (such as
intramuscular anesthetic and intravenous steroid injections) over more
traditional treatments (such as nonsteroidal anti-inflammatory drugs, epidural
injections, and oral psychotropic medications) for the treatment of mechanical
Reuben SS, Ekman EF. The effect of
cyclooxygenase-2 inhibition on analgesia and spinal fusion.
Joint Surg Am.2005;87:536-42.
Eighty patients undergoing a spinal fusion received either celecoxib (a
cyclooxygenase [COX]-II-specific inhibitor) or a placebo one hour before the
induction of anesthesia and every twelve hours for the following five days.
After a one year follow-up, it was found that the perioperative administration
of celecoxib resulted in a significant reduction of the consumption of pain
medication and had no effect on bone-healing as seen on plain radiographs and
tomograms and computed tomographic scans. The short-term use of a selective
COX-II inhibitor appears to be effective for pain relief within the first week
following surgery and should not result in any adverse effect on fusion
Riley LH 3rd, Skolasky RL, Albert TJ, Vaccaro AR,
Heller JG. Dysphagia after anterior cervical decompression and
fusion: prevalence and risk factors from a longitudinal cohort study.
In this prospective study, patients undergoing anterior cervical fusion
were evaluated preoperatively and at three, six, and twenty-four months
postoperatively with use of the Cervical Spine Research Society Outcome
Questionnaire, which includes questions evaluating dysphagia. At two years,
persistent dysphagia was observed in 21% of patients. A prolonged period of
preoperative symptoms was identified as a risk factor. Dysphagia was
associated with more disability and lower general health scores. Contrary to
the findings of other reports, dysphagia was not associated with the use of
plates or surgery at more rostral levels.
Rivero-Arias O, Campbell H, Gray A, Fairbank J,
Frost H, Wilson-MacDonald J. Surgical stabilisation of the spine
compared with a programme of intensive rehabilitation for the management of
patients with chronic low back pain: cost utility analysis based on a
randomised controlled trial.
This cost analysis demonstrated that surgical fusion of the lumbar spine in
patients with chronic back pain may not be a cost-effective use of health-care
resources, although this conclusion could change if the number of patients who
undergo rehabilitation and subsequently need surgery increases over time.
Taneichi H, Suda K, Kajino T, Kaneda K.
Traumatically induced vertebral artery occlusion associated with cervical
spine injuries: prospective study using magnetic resonance angiography.
Over a two-year period, sixty-four consecutive patients with cervical
fractures and/or dislocations underwent magnetic resonance angiography. Eleven
patients (17%) had vertebral artery occlusion, including ten patients who had
unilateral disease and one patient who had bilateral disease. Only the patient
who had bilateral disease had transient symptoms. All patients had an intact
circle of Willis. Follow-up magnetic resonance angiography demonstrated
reconstitution of blood flow in three patients. Unfortunately, similar to the
findings of other studies, no conclusions were available with regard to
whether vertebral artery injuries in the absence of neurologic changes are
clinically important or with regard to how such injuries should be
Wilson-MacDonald J, Burt G, Griffin D, Glynn
C. Epidural steroid injection for nerve root compression. A
randomised, controlled trial.
J Bone Joint Surg Br.2005;87:352-5.
In this prospective trial, patients with lumbar nerve root compression were
randomized to treatment with an epidural injection of steroid or an
intramuscular injection of local anesthetic and steroid. A significant
reduction in pain was noted in the early period following epidural steroid
injection, but there was no difference between the two groups with regard to
Yoshimoto H, Nagashima K, Sato S, Hyakumachi T,
Yanagibashi Y, Masuda T. A prospective evaluation of anesthesia for
posterior lumbar spine fusion: the effectiveness of preoperative epidural
anesthesia with morphine.
This randomized, controlled study of forty patients undergoing lumbar
fusion evaluated the effect of preoperative epidural anesthesia on blood loss,
intraoperative blood pressure, and postoperative analgesic requirements. The
use of epidural anesthesia was associated with a significantly lower
requirement for postoperative analgesics, lower pain scores, and more stable
blood pressure. No difference was observed with regard to the ability to
monitor the neurologic status postoperatively. This small study demonstrates
the potential benefits of preemptive analgesia with respect to postoperative
pain and outcomes.
Zucherman JF, Hsu KY, Hartjen CA, Mehalic TF,
Implicito DA, Martin MJ, Johnson DR 2nd, Skidmore GA, Vessa PP, Dwyer JW,
Puccio ST, Cauthen JC, Ozuna RM. A multicenter, prospective,
randomized trial evaluating the X STOP interspinous process decompression
system for the treatment of neurogenic intermittent claudication: two-year
This was a randomized, controlled study in which one group of patients was
managed nonoperatively for spinal stenosis and the other group was managed
with the "X STOP," which basically keeps the spinal segment in a
flexed position and prevents extension. The inclusion criteria for this
technique were quite strict. Pain had to be relieved during flexion and the
patients had to be able to walk fifty feet (15.2 m). At the time of the
two-year follow-up, the patients in the X STOP group were doing significantly
better than the patients who received nonoperative treatment with epidural
injections. It is very unclear which patients with spinal claudication can be
managed with this technique as opposed to requiring formal decompression.
Anderson PA, Rouleau JP, Toth J, Riew
DK. A comparison of simulator-tested and -retrieved cervical disc prostheses.
J Neurosurg Spine. 2004;2:
Atlas SJ, Keller RB, Wu YA, Deyo RA,
Singer DE. Long-term outcomes of surgical and nonsurgical management of
sciatica secondary to a lumbar disc herniation: 10 year results from the Maine
lumbar spine study. Spine. 2005;
Barnes B, Boden SD, Louis-Ugbo J, Tomak
PR, Park JS, Park MS, Minamide A. Lower dose of rhBMP-2 achieves spine fusion
when combined with an osteoconductive bulking agent in non-human primates.
Carreon LY, Glassman SD, Anekstein Y,
Puno RM. Platelet gel (AGF) fails to increase fusion rates in instrumented
posterolateral fusions. Spine. 2005;
Glassman SD, Bridwell K, Dimar JR,
Horton W, Berven S, Schwab F. The impact of positive sagittal balance in adult
spinal deformity. Spine.
Gun RT, Osti OL, O'Riordan A, Mpelasoka
F, Eckerwall CGM, Smyth JF. Risk factors for prolonged disability after
whiplash injury: a prospective study. Spine.
Hatta Y, Shiraishi T, Hase H, Yato Y,
Ueda S, Mikami Y, Harada T, Ikeda T, Kubo T. Is posterior spinal cord shifting
by extensive posterior decompression clinically significant for multisegmental
cervical spondylotic myelopathy? Spine.
Lemaire JP, Carrier H, Sariali el-H,
Skalli W, Lavaste F. Clinical and radiological outcomes with the Charite
artificial disc: a 10-year minimum follow-up. J Spinal Disord
Milbrandt TA, Johnston CE 2nd. Down
syndrome and scoliosis: a review of a 50-year experience at one institution.
Takayama H, Muratsu H, Doita M, Harada
T, Yoshiya S, Kurosaka M. Impaired joint proprioception in patients with
cervical myelopathy. Spine.
Thompson GH, Akbarnia BA, Kostial P,
Poe-Kochert C, Armstrong DG, Roh J, Lowe R, Asher MA, Marks DS. Comparison of
single and dual growing rod techniques followed through definitive surgery: a
preliminary study. Spine. 2005;
Toyone T, Tanaka T, Kato D, Kaneyama R.
Low-back pain following surgery for lumbar disc herniation. A prospective
study. J Bone Joint Surg Am. 2004;
Vaccaro AR, Patel T, Fischgrund J,
Anderson DG, Truumees E, Herkowitz H, Phillips F, Hilibrand A, Albert TJ. A
2-year follow-up pilot study evaluating the safety and efficacy of op-1 putty
(rhBMP-7) as an adjunct to iliac crest autograft in posterolateral lumbar
fusions. Eur Spine J.
Zhang YG, Guo X, Xu P, Kang LL, Li J.
Bone mesenchymal stem cells transplanted into rabbit intervertebral discs can
increase proteoglycans. Clin Orthop Relat Res.