An analysis of factors causing poor surgical outcome in patients with cervical myelopathy due to ossification of the posterior longitudinal ligament: anterior decompression with spinal fusion versus laminoplasty

OBJECTIVE

We compared the surgical outcome of anterior decompression with spinal fusion (ASF) with the surgical outcome of laminoplasty for patients with cervical myelopathy due to ossification of the posterior longitudinal ligament.

METHODS

The study group comprised 19 ASF patients (A-group) and 40 laminoplasty patients (P-group) treated from 1993 to 2002 with 1 year or longer follow-up. The Japanese Orthopedic Association scoring system was used to evaluate cervical myelopathy, and the recovery rate calculated 1 year after surgery.

RESULTS

The mean recovery rate was 68.4% in the A-group and 52.5% in the P-group (P<0.05). Fifteen patients had a recovery rate less than 40%: 2 in the A-group and 13 in the P-group. One P-group patient and none of the A-group patients developed postoperative aggravation of their neurologic status. The P-group was divided into 2 subgroups: a good outcome group comprising patients whose recovery rate was 40% or higher (n=27) and a poor outcome group comprising patients whose recovery rate was less than 40% (n=13). The mean age at surgery was 59.9 years in the good outcome group and 68.0 years in the poor outcome group (P<0.05). The mean range of intervertebral mobility at maximum cord compression level before surgery was 6.9 degrees in the good outcome group and 10 degrees in the poor outcome group (P<0.05).

CONCLUSIONS

These results demonstrated that the surgical outcome of ASF was superior to the surgical outcome of laminoplasty. Elderly patients treated with laminoplasty showed an especially poor surgical outcome. We suggest that hypermobility of vertebrae at the cord compression level is a risk factor for poor surgical outcome after laminoplasty. Based on these results, we recommend that ASF should be the first choice of treatment for patients with significant ossification of the posterior longitudinal ligament and a hypermobile cervical spine. When laminoplasty is used for such cases, the addition of posterior instrumented fusion would be desirable for stabilizing the spine and decreasing damage to the spinal cord.

Device for intervertebral assisted motion: technique and initial results

Object

The DIAM is a polyester-encased silicone interspinous dynamic stabilization device that can unload the anterior column and reestablish the functional integrity of the posterior column.

Methods

The DIAM was implanted in 104 patients between May 1, 2001 and October 30, 2001. A retrospective evaluation was performed based on chart review and patient questionnaire at a median follow-up interval of 18.1 months.

Results

Conclusions

The DIAM implant appears to be a useful and effective alternative in the surgical management of a wide range of lumbar disorders. Patient complications are few and satisfaction is high.

Clinical Characteristics and Surgical Management for Juxtafacet Cysts of the Lumbar Spine

Retrospective analysis of 10 cases of resection of symptomatic lumbar juxtafacet cysts in nine patients (mean age 65.4 years) investigated the relationship between surgical method and progression of spinal spondylolisthesis or cyst recurrence. Patient characteristics, surgical methods, and postoperative course were reviewed. The most common preoperative symptom, painful radiculopathy, occurred in all cases, followed by motor weakness in five, sensory loss in four, and intermittent claudication in four. All patients underwent bilateral total (n = 6) or partial laminectomy (n = 4), with minimal (n = 3) or no (n = 7) facetectomy. Cysts were gross totally resected in eight cases and partially resected in two. Concomitant fixation was not performed. Painful radiculopathy, motor weakness, and sensory disturbance all resolved, resulting in good or excellent outcome in all patients. Postoperative symptomatic spondylolisthesis had not been noted at mean 52.1 months postoperatively. However, new juxtafacet cysts were later detected on the contralateral side to the initial lesion in two patients. Surgical removal of juxtafacet cysts is recommended for immediate symptomatic relief. Concomitant spinal fixation to prevent progression of spinal spondylolisthesis or cyst recurrence depends on cyst size, involvement of surrounding structures, degree of preoperative spondylolisthesis, and facet joint destruction.

Effects of total facetectomy on the stability of lumbosacral spine

In present study, an anatomically accurate, validated in the entirenonlinear domain, three-dimensional finite elementmodel was used to investigate the biomechanical effects of facetectomy on the stability of the human lumbosacral spine. Bilateral total facetectomy was simulated at L4-L5 and L5-S1 levels. Flexion, extension, and axial torsion were applied using pure moment protocols. Total facetectomy increased spinal instability significantly under extension and axial rotation and not under flexion.

Measurement of the local pressure of the intervertebral foramen and the electrophysiologic values of the spinal nerve roots in the vertebral foramen

STUDY DESIGN

The intraoperative findings of the local pressure of the intervertebral foramen and the electrophysiologic values of the spinal nerve roots were evaluated.

OBJECTIVE

To investigate the neurophysiologic changes of the spinal nerve roots in the vertebral foramen.

SUMMARY OF BACKGROUND DATA

As far as we know, few reports have so far described the neurophysiologic changes of the spinal nerve roots in the vertebral foramen.

METHODS

The local pressure of the intervertebral foramen was continuously measured while the lumbar spine posture was changed in 66 vertebral foramens. In addition, 20 L5 nerve roots were electrophysiologically evaluated using the compound muscle action potentials (CMAPs) from tibialis anterior (TA) muscle after L5 nerve root stimulation.

RESULTS

The local pressure of the intervertebral foramen was significantly increased during lumbar spine extension (P < 0.001); moreover, the latency and amplitude of the CMAPs both significantly deteriorated in line with the increasing local pressure.

CONCLUSIONS

Our findings suggested that a double compression of the nerve root exists in lumbar spinal stenosis with lumbar spine extension, which includes the spinal canal and the vertebral foramen.

Predictors of pain and function in persons with spinal stenosis, low back pain, and no back pain

STUDY DESIGN

Longitudinal masked, double-controlled cohort study.

OBJECTIVES

To determine prognosis and predictors of function and pain in persons with spinal stenosis.

SUMMARY OF BACKGROUND DATA

The clinical syndrome of spinal stenosis is common and disabling, but not clearly related to anatomic measures. Prognosis not well studied.

METHODS

Persons 55 to 80 years of age with and without stenosis on preliminary review of magnetic resonance imaging (MRI), and asymptomatic volunteers underwent screening, questionnaires, physical examination, ambulation testing, masked electromyogram (EMG), and masked MRI scans; these were repeated at >18 months.

RESULTS

Twenty-three asymptomatic, 28 back pain, and 32 clinically diagnosed stenosis subjects underwent follow-up. Although initial and follow-up diagnosis tended to agree (kappa = 0.394, P < 001), there were substantial shifts between the three groups. Among persons with clinically diagnosed stenosis, every measure trended for improvement, including significant changes in pain, ambulation, and EMG. Ambulation velocity and Pain Disability Index at follow-up were predicted by initial disability measures. Pain was predicted by initial sleep difficulty but not initial pain. EMG and MRI did not predict function or pain.

CONCLUSION

Clinically recognized spinal stenosis is fluctuating and largely improving, and in continuum with back pain and no symptoms. Since anatomic and neurologic deficits do not predict future function, they should not be weighed heavily in surgical risk-benefit discussions.

Effects of X-STOP device on sagittal lumbar spine kinematics in spinal stenosis

The X-Stop device is designed to distract the posterior elements of the stenotic segment and place it in flexion to treat neurogenic claudication. Previous biomechanical studies on X Stop have been done in vitro on cadavers looking at disc pressures and segmental range of movements. The objective of this study is to understand the sagittal kinematics in vivo of the lumbar spine at the instrumented and adjacent levels. Twenty-six patients with lumbar spine stenosis underwent 1 or 2 level X-Stop procedure. All had pre- and postoperative positional magnetic resonance imaging (MRI) in standing, supine, and sitting in flexion and extension. Measurements of disc heights, endplate angles, segmental and lumbar range of movement were performed after placement of X Stop at the stenosed level in patients with lumbar spinal stenosis. No significant changes were seen in disc heights, segmental and total lumbar spine movements postoperatively. The X-Stop device does not affect the sagittal kinematics of the lumbar spine in vivo.

MRI images at a 45-degree angle through the cervical neural foramina: a technique for improved visualization

BACKGROUND

Traditional MRI imaging of the cervical neural foramina (NF) generally utilizes sagittal and axial views to delineate pathology. These views may not fully delineate NF pathology. Enhanced imaging and visualization of this area would benefit all interventionalists. The spinal interventionalist, in particular, routinely utilizes approximately a 45-degree fluoroscopic en face view for placement of needles for a cervical transforaminal epidural. The interventionalist relies on axial MRI views to identify NF pathology that can be conceptually more difficult to analyze. Routine 45-degree oblique views through the NF, along with traditional axial views for correlation, more clearly demonstrate NF pathology.

CASES

Two cases are presented in which the 45-degree oblique views more clearly demonstrate neural foramina pathology.

CONCLUSION

These clinical cases demonstrate the clinical utility of the cervical spine MRI 45 degree oblique technique and show cervical NF pathology that is not as easily identified on routine axial and sagittal sequences. We advocate the routine acquisition and examination of 45-degree cuts to help spinal practitioners better delineate NF pathology.

Disability in patients with degenerative lumbar spinal stenosis

OBJECTIVE

To determine factors associated with disability in patients with degenerative lumbar spinal stenosis.

DESIGN

One-group cross-sectional study.

SETTING

University hospital.

PARTICIPANTS

One hundred eight patients with degenerative lumbar spinal stenosis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Oswestry Disability Index and 4 categories of factors, including patient demographics (age, sex, number of comorbidities, medications), symptom-related factors (intensity, location, onset duration, neurogenic claudication), body structure and function as described in the International Classification of Functioning, Disability and Health model (muscle strength, vibration sense, spine flexibility), and stenotic condition (type and number of spinal segments involved).

RESULTS

Patients with symptoms in both back and leg reported greater disability than those with symptoms only in the leg or back (P=.008). Greater disability correlated significantly with greater symptom intensity (r=.385, P<.001) and higher vibration threshold (r=.236, P=.014). While controlling the variance in patient demographics in the regression analysis, vibration sense and symptom location each added 10% of the variance in disability, and symptom intensity and strength each added 5%, with a total of 44% variance explained (P=.044).

CONCLUSIONS

Symptom intensity and location, vibration sense, and muscle strength were identified as significant factors and, together with patient demographics, accounted for 44% of the variance explained in disability. Further investigations are needed to determine if causal relationships exist between these factors and disability.

Short Form–36 outcomes following focal 1- and 2-level cervical laminectomy with multilevel instrumented fusion

BACKGROUND

Multilevel laminectomy with instrumented fusion addresses diffuse dorsal cord compression with an adequately preserved cervical lordosis. However, for patients with only 1 to 2 laminar impingement, more "focal" laminectomy and fusion may suffice, the shortened laminectomy allowing for a more simple spinous process fusion skipping the 1 or 2 lamina that have been removed.

METHODS

Fourteen patients presented with severe spastic myeloradiculopathy (Nurick grade IV) attributed to magnetic resonance imaging- and CT-documented 1- to 2-level laminar compression, stenosis, and ossification of the yellow ligament. Magnetic resonance images also revealed 1- to 2-level hyperintense signals within the cord at the levels of maximal compromise. Surgical procedures included 1- to 2-level laminectomies and average 6.4-level posterior fusions. Dynamic x-ray/CT studies, which were obtained 3, 6, and up to 12 months postoperatively, followed progression toward fusion. Outcomes were assessed using Nurick grades (0-V) and SF-36 questionnaires assessed preoperatively and up to 12 months postoperatively.

RESULTS

Patients improved on all 8 SF-36 Health Scales within the first postoperative year. Maximal improvement was observed on 5 Health Scales within the first 6 postoperative months (physical function, mental health, vitality, general health, role physical). The preoperative average Nurick grade (3.8) improved postoperatively (0.7 at 6 months, 0.5 at 1 year). Dynamic x-ray and CT studies documented fusion for all 14 patients by the sixth postoperative month.

CONCLUSIONS

One- and two-level cervical laminectomies with multilevel-instrumented fusion effectively decompressed "focal" cord compression, whereas fusion maintained the cervical lordotic curvature and provided stability to avert future disease progression.

Preoperative predictors for postoperative clinical outcome in lumbar spinal stenosis: systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To define preoperative factors predicting clinical outcome after lumbar spinal stenosis (LSS) surgery.

SUMMARY OF BACKGROUND DATA

LSS is the most common reason requiring lumbar spine surgery in adults older than 65 years. There are no published systematic reviews on this topic.

METHODS

A literature search was done until April 30, 2005. Included were randomized controlled or controlled trials or prospective studies dealing with operated LSS. The preoperative predictors had to be presented. Included articles were assessed as high-quality (HQ) and low-quality studies. The predictors in HQ studies were considered as the main results.

RESULTS

A total of 21 articles were included. Depression and walking capacity were predictors according to 2 HQ studies. Predictors reported in 1 HQ study were cardiovascular/overall comorbidity, disorder influencing walking ability, self-rated health, income, severity of central stenosis, and scoliosis.

CONCLUSION

Depression, cardiovascular comorbidity, disorder influencing walking ability, and scoliosis predicted poorer subjective outcome. Better walking ability, self-rated health, higher income, less overall comorbidity, and pronounced central stenosis predicted better subjective outcome. Male gender and younger age predicted better postoperative walking ability. The predictive value may be outcome specific; thus, the use of all relevant outcome measures is recommended when studying predictors of LSS.

Spinal stenosis, back pain, or no symptoms at all? A masked study comparing radiologic and electrodiagnostic diagnoses to the clinical impression

OBJECTIVE

To assess the relations between clinically recognized lumbar spinal stenosis and the conclusions of masked radiologists and electrodiagnosticians.

DESIGN

Prospective, masked, double-controlled trial.

SETTING

University spine center.

PARTICIPANTS

One hundred fifty persons age 55 to 80 years with or without back pain and with or without magnetic resonance imaging (MRI)-demonstrated stenosis, screened for neuropathy risk, previous surgery, or cancer.

INTERVENTIONS

Questionnaires on pain and function; ambulation testing and physical examination; and masked electrodiagnotics and MRI.

MAIN OUTCOME MEASURE

Diagnostic impressions of the examining clinician, radiologist, and electrodiagnostician.

RESULTS

Following application of post hoc exclusion criteria and elimination of patients due to incomplete or inadequate test data, the clinical diagnosis was lumbar stenosis in 50 subjects, back pain in 44 subjects, and no pain in 32 subjects. Radiologic and clinical impression had no relation (P = .80 vs asymptomatic, P = .99 vs back pain controls). Electrodiagnostic impression trended to relate to clinical impression (P = .14 vs asymptomatic, P = .09 vs back pain). Retrospective application of age-related electrodiagnostic norms for paraspinal electromyographic and limb motor unit changes, established in this study, reclassified 13 of the 17 asymptomatic persons whom the electrodiagnostician thought had stenosis. The clinical impression did correspond to history and physical examination findings typically associated with spinal stenosis and to the independent impression of a neurosurgeon who examined MRI and clinical, but not to the electrodiagnostic data.

CONCLUSIONS

The impression obtained from an MRI scan does not determine whether lumbar stenosis is a cause of pain. Electrodiagnostic consultation may be useful, especially if age-related norms obtained in this study are applied.

Functional outcome of surgical treatment for multilevel lumbar spinal stenosis

BACKGROUND

There is no consensus regarding the best treatment of patients with multilevel lumbar stenosis. We evaluated the clinical and radiological findings in 41 patients with complex degenerative spinal stenosis of the lumbar spine who were treated surgically.

METHODS

Between 1997 and 2003, 41 patients suffering from degenerative lumbar spinal stenosis were included in a prospective clinical study. The spinal stenosis was multilevel in all patients and in 13 of them there was degenerative scoliosis, in 18 there was degenerative spondylolisthesis, and in 10 there was segmental instability. Plain radiographs, MRI and/or CT myelograms were obtained preoperatively. The patients were assessed clinically with the Oswestry disability index (ODI) and visual analog scale (VAS). Surgery included wide posterior decompression and fusion using a trans-pedicular instrumentation system and bone graft.

RESULTS

After a mean follow-up of 3.7 (1-6) years, the patients' clinical improvement on the ODI and VAS was statistically significant. Recurrent stenosis was not observed, and 39 of 41 patients were satisfied with the outcome. 3 patients with improvement initially had later surgery because of instability.

INTERPRETATION

The above-mentioned technique gives good and long lasting clinical results, when selection of patients is done carefully and when the spinal levels that are to be decompressed are selected accurately.

Comparison of radiologic signs and clinical symptoms of spinal stenosis

STUDY DESIGN

Clinical findings of spinal stenosis were compared to graded radiologic findings of dural sac narrowing.

OBJECTIVES

To examine the changes of the dural sac area of the lumbar spine on computerized tomography (CT) performed without and with axial loading, and study the correlations between the radiologic findings and clinical symptoms suggestive of spinal stenosis.

SUMMARY OF BACKGROUND DATA

Although several studies have been performed regarding the advantage of an external compression device in lumbar CT, to our knowledge, none of these studies have correlated radiologic findings with clinical symptoms.

METHODS

The cross-sectional areas of the dural sac at the 3 lowest lumbar intravenous spaces, measured by CT both without and with external compression, were correlated to the clinical symptoms suggestive of spinal stenosis in 117 patients and 351 intervertebral levels.

RESULTS

No statistically significant correlation between the severity of the clinical symptoms of spinal stenosis and dural cross-sectional areas was found. Neither did the use of an external compression device improve the correlation.

CONCLUSION

Although an external compression simulates the dynamic condition in the back during standing position, it does not eliminate the need to compare the radiologic findings with the clinical symptoms of patients examined because of a suspected narrowing of the spinal canal.

Five-year outcomes of surgical treatment for degenerative lumbar spinal stenosis: a prospective observational study of symptom severity at standard intervals after surgery

STUDY DESIGN

A prospective observational study of patients undergoing surgery for degenerative lumbar spinal stenosis.

OBJECTIVE

To determine whether the long-term outcomes differ as a function of age and gender.

SUMMARY OF BACKGROUND DATA

The long-term results of surgery for lumbar spinal stenosis are not well understood, and the patient characteristics that predispose patients to worse outcomes are unknown.

METHODS

Seventy patients who underwent decompressive laminotomy with or without arthrodesis for degenerative lumbar spinal stenosis were prospectively studied at standard intervals after surgery with respect to symptom severity rated on a visual analog scale (VAS).

RESULTS

The VAS scores for younger patients improved steadily for 3 or 6 months, after which the improvement was maintained until 60 months. The VAS scores for older patients showed a similar time course until 36 months, after which the VAS scores were worse compared with those for younger patients. The VAS scores for females were worse than those for males, in three symptoms queried, at one or more of the evaluation time points.

CONCLUSION

In patients undergoing surgery for degenerative lumbar spinal stenosis, older age predicts a greater risk of late recurrence of symptoms, and women have higher VAS scores than men after surgery.

Head-turned rear impact causing dynamic cervical intervertebral foramen narrowing: implications for ganglion and nerve root injury

OBJECT

A rotated head posture at the time of vehicular rear impact has been correlated with a higher incidence and greater severity of chronic radicular symptoms than accidents occurring with the occupant facing forward. No studies have been conducted to quantify the dynamic changes in foramen dimensions during head-turned rear-impact collisions. The objectives of this study were to quantify the changes in foraminal width, height, and area during head-turned rear-impact collisions and to determine if dynamic narrowing causes potential cervical nerve root or ganglion impingement.

METHODS

The authors subjected a whole cervical spine model with muscle force replication and a surrogate head to simulated head-turned rear impacts of 3.5, 5, 6.5, and 8 G following a noninjurious 2-G baseline acceleration. Continuous dynamic foraminal width, height, and area narrowing were recorded, and peaks were determined during each impact; these data were then statistically compared with those obtained at baseline. The authors observed significant increases (p < 0.05) in mean peak foraminal width narrowing values greater than baseline values, of up to 1.8 mm in the left C5-6 foramen at 8 G. At the right C2-3 foramen, the mean peak dynamic foraminal height was significantly narrower than baseline when subjected to rear-impacts of 5 and 6.5 G, but no significant increases in foraminal area were observed. Analysis of the results indicated that the greatest potential for cervical ganglion compression injury existed at C5-6 and C6-7. Greater potential for ganglion compression injury existed at C3-4 and C4-5 during head-turned rear impact than during head-forward rear impact.

CONCLUSIONS

Extrapolation of present results indicated potential ganglion compression in patients with a non-stenotic foramen at C5-6 and C6-7; in patients with a stenotic foramen the injury risk greatly increases and spreads to include the C3-4 through C6-7 as well as C4-5 through C6-7 nerve roots.

Paragliding accidents with spinal cord injury: 10 years' experience at a single institution

STUDY DESIGN

A retrospective analysis of 41 patients with spinal cord injury (SCI) after paragliding accidents.

OBJECTIVE

To determine the lesioned pattern and prognostic radiologic factors for rehabilitation potential.

SUMMARY OF BACKGROUND DATA

Paragliding accidents with SCI present a new injury pattern, dealt with in the current literature from a purely orthopedic, sports medicine, or insurance point of view. Few combinations of orthopedic and neurologic data are available.

METHODS

Over a 10-year period, the case records of 41 patients with SCI caused by paragliding accidents were analyzed with regard to vertebral and other skeletal fractures, neurologic recovery (American Spine Injury Association score), and professional reintegration.

RESULTS

Vertebral fractures peaked in the thoracolumbar region, with L1 most frequently (30%) affected. The levels of vertebral lesion and neurologic deficit differed in 32% of patients. Combination with lower-limb fractures was characteristic for paragliding SCI (P < 0.001); 93% of patients with initial bony occlusion of the spinal canal of <70% left the clinic ambulatory.

CONCLUSION

Paragliding accidents with SCI show a characteristic injury pattern associated with a high recovery potential if the initial bony spinal canal occlusion is <70%. Half the patients will reintegrate in their former profession and place of employment.

Effect of bilateral facetectomy of thoracolumbar spine T11–L1 on spinal stability

Spinal stenosis can be found in any part of the spine, though it is most commonly located on the lumbar and cervical areas. It has been documented in the literature that bilateral facetectomy in a lumbar motion segment to increase the space induces an increase in flexibility at the level at which the surgery was performed. However, the result of bilateral facetectomy on the stability of the thoracolumbar spine has not been studied. A nonlinear three-dimensional finite element (FE) model of thoracolumbar T11-L1 was built to explore the influence of bilateral facetectomy. The FE model of T11-L1 was validated against published experimental results under various physiological loadings. The FE model with bilateral facetectomy was evaluated under flexion, extension, lateral bending and axial rotation to determine alterations in kinematics. Results show that bilateral facetectomy causes increase in motion, considerable increase in axial rotation and least increase in lateral bending. Removal of facets did not result in significant change in the sagittal motion in flexion and extension.

C3-6 laminoplasty takes over C3-7 laminoplasty with significantly lower incidence of axial neck pain

Five-lamina (C3-7) procedure is the most popular cervical laminoplasty and there have been no studies on the most appropriate number of laminae to be opened. We prospectively reduced the range of laminoplasty from C3-7 to C3-6 in 2002 and compared the outcome of C3-6 laminoplasty (n=37) to that of C3-7 laminoplasty (n=28). In both groups, neurological gain was satisfactory, radiographic changes were minimal, and postoperative MRI indicated sufficient expansion of the dura and the spinal cord. Average operating period was significantly shorter, and length of the operative wound was significantly less in the C3-6 group than in the C3-7 group. Postoperative axial neck pain was significantly rarer after C3-6 laminoplasty than after C3-7 laminoplasty (5.4% vs. 29%, P=0.015). Due to its simplicity and various benefits, C3-6 laminoplasty is a promising alternative to conventional C3-7 laminoplasty for treatment of multisegmental compression myelopathy.

The bent spine syndrome: myopathy + biomechanics = symptoms

BACKGROUND CONTEXT

The bent spine syndrome, which mimics spinal stenosis, is thought to be a focal paraspinal myopathy, but because paraspinal fatigue with ambulation is not a feature of more severe myopathies, the cause of symptoms is not clear.

PURPOSE

To evaluate electromyographic and biomechanical aspects of the bent spine syndrome.

STUDY DESIGN/SETTING

University spine clinic.

METHODS

A patient with severe disability from the bent spine syndrome was compared with a fortuitously discovered asymptomatic research subject with the syndrome, in terms of physical examination, magnetic resonance imaging, and electrodiagnostic testing.

RESULTS

Both subjects had fatty paraspinal replacement on magnetic resonance imaging and electromyography. More detailed electromyography of the patient showed abnormalities medially and caudally, but changes including apparent myopathic motor units up to the high thoracic region. The research subject had no hip flexion contracture, whereas the patient had severe contracture. Correction of contracture increased ambulation from 20 to 300 meters.

CONCLUSIONS

Bent spine syndrome is likely a paraspinal myopathy, but symptoms do not occur unless there is also a hip flexion contracture.

Changes of interleukin-6 and related factors as well as gastric intramucosal pH during colorectal and orthopaedic surgical procedures

OBJECTIVE

To investigate the changes of perioperative serum levels of interleukin-6 (IL-6), C-reactive protein (CRP), and cortisol, as well as gastric intramucosal pH (pHi) and plasma lactate, aiming to compare systemic changes and tissue perfusion during colorectal and orthopaedic surgical procedures.

METHODS

Twenty patients were randomly assigned to two groups, 10 cases of operation on vertebral canal, 10 cases of colorectal radical operation. Venous blood was drawn at 1 day before operation, 2, 4, and 6 hours following skin incision, and 1 day after operation, in order to measure serum IL-6, CRP, and cortisol. pHi and plasma lactate were also measured at the same time points.

RESULTS

Serum concentrations of IL-6 and cortisol increased gradually following operation, reaching the peak value at 6 hours from the beginning of operation. CRP was not detectable until the first day after operation. Peak concentration of IL-6 had positive relationship with CRP. These variables changed more significantly in colorectal group than that in orthopaedic group (P < 0.05). pHi decreased gradually, reaching the lowest level at 4 hours from the beginning of operation, and to more extent in colorectal group than that in orthopaedic group (P < 0.05).

CONCLUSION

IL-6 may reflect tissue damage more sensitively than CRP. Colorectal surgery might induce systemic disorder to more extent, in terms of immuno-endocrinal aspect as well as tissue perfusion, reflected with pHi.

A non-surgical approach to the management of lumbar spinal stenosis: a prospective observational cohort study

Background

While it is widely held that non-surgical management should be the first line of approach in patients with lumbar spinal stenosis (LSS), little is known about the efficacy of non-surgical treatments for this condition. Data are needed to determine the most efficacious and safe non-surgical treatment options for patients with LSS. The purpose of this paper is to describe the clinical outcomes of a novel approach to patients with LSS that focuses on distraction manipulation (DM) and neural mobilization (NM).

Methods

This is a prospective consecutive case series with long term follow up (FU) of fifty-seven consecutive patients who were diagnosed with LSS. Two were excluded because of absence of baseline data or failure to remain in treatment to FU. Disability was measured using the Roland Morris Disability Questionnaire (RM) and pain intensity was measured using the Three Level Numerical Rating Scale (NRS). Patients were also asked to rate their perceived percentage improvement.

Results

The mean patient-rated percentage improvement from baseline to the end to treatment was 65.1%. The mean improvement in disability from baseline to the end of treatment was 5.1 points. This was considered to be clinically meaningful. Clinically meaningful improvement in disability from baseline to the end of treatment was seen in 66.7% of patients. The mean improvement in "on average" pain intensity was 1.6 points. This did not reach the threshold for clinical meaningfulness. The mean improvement in "at worst" pain was 3.1 points. This was considered to be clinically meaningful.

The mean duration of FU was 16.5 months. The mean patient-rated percentage improvement from baseline to long term FU was 75.6%. The mean improvement in disability was 5.2 points. This was considered to be clinically meaningful. Clinically meaningful improvement in disability was seen in 73.2% of patients. The mean improvement in "on average" pain intensity from baseline to long term FU was 3.0 points. This was considered to be clinically meaningful. The mean improvement in "at worst" pain was 4.2 points. This was considered to be clinically meaningful. Only two patients went on to require surgery.

No major complications to treatment were noted.

Conclusion

A treatment approach focusing on DM and NM may be useful in bringing about clinically meaningful improvement in disability in patients with LSS.

F wave studies of neurogenic intermittent claudication in lumbar spinal stenosis

OBJECTIVE

Lumbar spinal stenosis (LSS) may result in neurogenic claudication (NC), which is thought to be a result of transient ischemia during exercise. In this study we evaluated the changes in F wave studies before and immediately after walking stress in patients with NC.

DESIGN

Twenty-six patients with LSS who had signs and symptoms of NC and 20 healthy volunteers were included in this study. Routine motor and sensory nerve conduction studies and tibial F wave studies were performed in both groups. Immediately after walking stress test, tibial F wave studies were repeated. Exercise treadmill protocol was used for ambulation. Time to first symptoms and total ambulation time were recorded.

RESULTS

After completion of the baseline electrophysiological examination, a walking stress test was performed using a treadmill, and 16 patients (61.5%) experienced neurogenic claudication during the trial. The mean time to first symptoms was 2.0 +/- 3.5 mins (minimum = 0, maximum = 14). In the control group 18 subjects (90%) completed the trial without any symptoms, and 2 (10%) subjects had to stop at an average of 10 mins because of generalized fatigue. Within 5 mins after the walking stress test, tibial F wave studies were repeated in both groups. There were significant increases in F latency values bilaterally in the patient group (P = 0.001 for both sides) but not in control subjects (P = 0.435 for right side and P = 0.122 for left side).

CONCLUSION

Our data suggest that F wave studies after walking stress test provide more information for the diagnosis of NC.

Outcome after less-invasive decompression of lumbar spinal stenosis: a randomized comparison of unilateral laminotomy, bilateral laminotomy, and laminectomy

OBJECT

Recently, limited decompression procedures have been proposed in the treatment of lumbar stenosis. The authors undertook a prospective study to compare the safety and outcome of unilateral and bilateral laminotomy with laminectomy.

METHODS

One hundred twenty consecutive patients with 207 levels of lumbar stenosis without herniated discs or instability were randomized to three treatment groups (bilateral laminotomy [Group 1], unilateral laminotomy [Group 2], and laminectomy [Group 3]). Perioperative parameters and complications were documented. Symptoms and scores, such as visual analog scale (VAS), Roland-Morris Scale, Short Form-36 (SF-36), and patient satisfaction were assessed preoperatively and at 3, 6, and 12 months after surgery. Adequate decompression was achieved in all patients. The overall complication rate was lowest in patients who had undergone bilateral laminotomy (Group 1). The minimum follow up of 12 months was obtained in 94% of patients. Residual pain was lowest in Group 1 (VAS score 2.3 +/- 2.4 and 4 +/- 1 in Group 3; p < 0.05 and 3.6 +/- 2.7 in Group 2; p < 0.05). The Roland-Morris Scale score improved from 17 +/- 4.3 before surgery to 8.1 +/- 7, 8.5 +/- 7.3, and 10.9 +/- 7.5 (Groups 1-3, respectively; p < 0.001 compared with preoperative) corresponding to a dramatic increase in walking distance. Examination of SF-36 scores demonstrated marked improvement, most pronounced in Group 1. The number of repeated operations did not differ among groups. Patient satisfaction was significantly superior in Group 1, with 3, 27, and 26% of patients unsatisfied (in Groups 1, 2, and 3, respectively; p < 0.01).

CONCLUSIONS

Bilateral and unilateral laminotomy allowed adequate and safe decompression of lumbar stenosis, resulted in a highly significant reduction of symptoms and disability, and improved health-related quality of life. Outcome after unilateral laminotomy was comparable with that after laminectomy. In most outcome parameters, bilateral laminotomy was associated with a significant benefit and thus constitutes a promising treatment alternative.

[The relationship between objective and subjective evaluation criteria in lumbar spinal stenosis]

OBJECTIVES

We evaluated the relationship between functional objective and patient-based subjective assessments and quality of life in patients with lumbar spinal stenosis (LSS).

METHODS

Thirty patients (25 females, 5 males; mean age 62+/-9 years; range 41-78 years) were prospectively studied. All were diagnosed as having LSS by clinical and radiological evaluations. Pain was assessed by a visual analog scale. The patients were evaluated by the two-staged treadmill exercise tolerance (TET) test, SF-36 health status survey, and Oswestry Disability Index (ODI). The relationships between the TET test, which is an objective functional assessment, and patient-based assessments (SF-36 and ODI), pain and age were investigated.

RESULTS

There were significant differences between the functional grades of the patients at the speed of 1.9 km/hour with respect to ODI scores, the physical component scale of SF-36, age, and the preferred speed of the patients (p<0.05). These differences emerged from the fourth functional stage (p<0.01). Oswestry disability scores and the physical component scores of SF-36 worsened in parallel with the stages of the TET test. The preferred speed of the patients at the TET test was positively correlated with the physical component scores of SF-36 and negatively correlated with Oswestry disability scores (p<0.05). There was a negative correlation between the physical component scores of SF-36 and Oswestry disability scores (p<0.05).

CONCLUSION

The TET test used to determine the functional capacity seems to be correlated well with subjective patient-based assessments. This objective tool, when combined with subjective assessments, may be helpful in the evaluation and treatment of patients with LSS.

Force plate analysis before and after dorsal decompression for treatment of degenerative lumbosacral stenosis in dogs

OBJECTIVE

Using force plate analysis (FPA), determine ground reaction forces in dogs with degenerative lumbosacral stenosis (DLS) and evaluate the effects of lumbosacral decompressive surgery.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Twelve dogs with DLS.

METHODS

DLS was diagnosed by clinical signs, radiography, computed tomography, and/or magnetic resonance imaging. FPA was performed before surgery, and 3 days, 6 weeks, and 6 months after surgery. The mean peak braking (Fy+), peak propulsive (Fy-), and peak vertical (Fz+) forces of 8 consecutive strides were determined. The ratio between the total Fy- of the pelvic limbs and the total Fy- of the thoracic limbs (P/TFy-), reflecting the distribution of Fy-, was analyzed to evaluate any changes in locomotion pattern postoperatively. Ground reaction force data for DLS dogs were compared with data derived from 24 healthy dogs (control).

RESULTS

In dogs with DLS, the propulsive forces (Fy-) of the pelvic limbs were significantly smaller than those of controls. P/TFy- was significantly smaller in dogs with DLS than in control dogs, and increased during the follow-up period, reaching normal values 6 months after surgery.

CONCLUSIONS

Cauda equina compression in dogs with DLS decreases the propulsive force of the pelvic limbs and surgical treatment restores the propulsive force of the pelvic limbs in a 6-month period.

CLINICAL RELEVANCE

In dogs with DLS, FPA is an effective method in evaluating the response to surgical treatment. Normal propulsive force in the pelvic limbs was restored during 6 months after decompressive surgery.

The sensitivity and specificity of electrodiagnostic testing for the clinical syndrome of lumbar spinal stenosis

STUDY DESIGN

Prospective, masked, double controlled diagnostic trial.

OBJECTIVES

To determine the sensitivity and specificity of electrodiagnostic consultation (EDX) for the clinical syndrome of lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

EDX has been used for more than 50 years to diagnose spinal disorders but has not met the new standards of evidence-based medicine.

METHODS

A total of 150 subjects (asymptomatic volunteers and patients with MRIs suggesting back pain or spinal stenosis; 55-80 years of age) underwent physiatrist history and physical examination, MRI, and review of this data by a neurosurgeon, with each clinician masked to any outside information, leading to a unanimous consensus on diagnosis in 55. After masked EDX testing, 7 subjects with undiagnosed neuromuscular disease were discovered. EDX findings were related to "clinical gold standard" diagnoses in 48 persons.

RESULTS

Paraspinal mapping EMG score of >4 had 100% specificity and 30% sensitivity for stenosis compared with either the back pain or asymptomatic groups (each, P < 0.04). A composite limb and paraspinal fibrillation score had a sensitivity of 47.8% and specificity of 87.5% (P = 0.008), and H-wave sensitivity was 36.4, specificity 91.3 (P = 0.026) for stenosis versus all controls.

CONCLUSIONS

This first masked study in the 60-year history of needle electromyography also introduces anatomically validated needle placement, quantified and reproducible examination of the paraspinal muscles, and dual control populations to EDX research in spinal disorders. EDX has statistically significant, clinically meaningful specificity for spinal stenosis and detects neuromuscular diseases that may masquerade as stenosis.

Hypertrophy of ligamentum flavum in lumbar spinal stenosis associated with increased proteinase inhibitor concentration

BACKGROUND

It is well known that age-related fibrosis, or decreases in the elastin-to-collagen ratio of the ligamentum flavum, along with hypertrophy of the ligamentum flavum, are associated with lumbar spinal stenosis. However, the molecular mechanism by which this fibrosis and hypertrophy develop is unknown. Tissue inhibitors of matrix metalloproteinase (TIMPs) are proteinase inhibitors that suppress extracellular matrix degradation. Elevated TIMP-1 and TIMP-2 expression has been implicated in various fibrotic diseases of the liver, kidney, lung, and heart. These TIMPs can also induce cellular proliferation and inhibit apoptosis in a wide range of cell types. These findings led us to postulate that TIMP-1 and TIMP-2 might also be associated with hypertrophy and fibrosis of the ligamentum flavum in lumbar spinal stenosis.

METHODS

We quantified and localized TIMP expression in ligamentum flavum tissues that had been obtained during surgery from thirty patients with spinal stenosis and from thirty gender-matched control patients with disc herniation. The thickness of the ligamentum flavum at the level of the facet joint was measured on axial T1-weighted magnetic resonance images. In addition, we examined ligamentum flavum tissues for the expression of markers of cellular proliferation and apoptosis.

RESULTS

The ligamentum flavum was significantly thicker in the patients with spinal stenosis (mean, 5.68 mm) than in the patients with disc herniation (mean, 2.70 mm) (p < 0.001). The concentration of TIMP-2 in the ligamentum flavum was significantly higher in the patients with spinal stenosis (mean, 12.62 ng/mL) than in those with disc herniation (mean, 8.85 ng/mL) (p = 0.028). TIMP-1 and TIMP-2 were detected in the cytoplasm of ligamentum flavum fibroblasts. TIMP-1 and TIMP-2 concentrations were associated with hypertrophy of the ligamentum flavum (p = 0.015 and p = 0.003, respectively). None of the samples from the patients with stenosis had evidence of proliferation of ligamentum flavum fibroblasts. The expression of markers for apoptosis was significantly higher in the patients with spinal stenosis (58.8%) than in those with disc herniation (26.6%) (p < 0.001).

CONCLUSIONS

Increased TIMP expression has been implicated in fibrosis and hypertrophy of the extracellular matrix of several organs. Our results suggest that increased expression of TIMP-2 in ligamentum flavum fibroblasts is associated with fibrosis and hypertrophy of the ligamentum flavum in patients with spinal stenosis.

Pathomechanism of ligamentum flavum hypertrophy: a multidisciplinary investigation based on clinical, biomechanical, histologic, and biologic assessments

STUDY DESIGN

A multidisciplinary study involving clinical, histologic, biomechanical, biologic, and immunohistologic approaches. OBJECTIVE.: To clarify the pathomechanism of hypertrophy of the ligamentum flavum.

SUMMARY OF BACKGROUND DATA

The most common spinal disorder in elderly patients is lumbar spinal canal stenosis, causing low back and leg pain, and paresis. Canal narrowing, in part, results from hypertrophy of the ligamentum flavum. Although histologic and biologic literature on this topic is available, the pathomechanism of ligamentum flavum hypertrophy is still unknown.

METHODS

The thickness of 308 ligamenta flava at L2/3, L3/4, L4/5, and L5/S1 levels of 77 patients was measured using magnetic resonance imaging. The relationships between thickness, age, and level were evaluated. Histologic evaluation was performed on 20 ligamentum flavum samples, which were collected during surgery. Trichrome and Verhoeff-van Gieson elastic stains were performed for each ligamentum flavum to understand the degree of fibrosis and elastic fiber status, respectively. To understand the mechanical stresses in various layers of ligamentum flavum, a 3-dimensional finite element model was used. Von Mises stresses were computed, and values between dural and dorsal layers were compared. There were 10 ligamenta flava collected for biologic assessment. Using real-time reverse transcriptase polymerase chain reaction, transforming growth factor (TGF)-beta messenger ribonucleic acid expression was quantitatively measured. The cellular location of TGF-beta was also confirmed from 18 ligamenta flava using immunohistologic techniques.

RESULTS

The ligamentum flavum thickness increased with age, however, the increment at L4/5 and L3/4 levels was larger than at L2/3 and L5/S1 levels. Histology showed that as the ligamentum flavum thickness increased, fibrosis increased and elastic fibers decreased. This tendency was more predominant along the dorsal side. Von Misses stresses revealed that the dorsal fibers of ligamentum flavum were subjected to higher stress than the dural fibers. This was most remarkably observed at L4/5. The largest increase in ratio observed between the dorsal and dural layer was approximately 5-fold in flexion at L4/5 in flexion. Expression of TGF-beta was observed in all ligamenta flava, however, the expression decreased as the ligamentum flavum thickness increased. Immunohistochemistry showed that TGF-beta was released by the endothelial cells, not by fibroblasts.

CONCLUSIONS

Fibrosis is the main cause of ligamentum flavum hypertrophy, and fibrosis is caused by the accumulation of mechanical stress with the aging process, especially along the dorsal aspect of the ligamentum flavum. TGF-beta released by the endothelial cells may stimulate fibrosis, especially during the early phase of hypertrophy.

Ectopic firing due to artificial venous stasis in rat lumbar spinal canal stenosis model: a possible pathogenesis of neurogenic intermittent claudication

STUDY DESIGN

An electrophysiologic analysis was performed on a chronic lumbar spinal stenosis model of rats. The effects of venous stasis on ectopic firing originating in the nerve root were investigated.

OBJECTIVES

To elucidate the mechanisms of neurogenic intermittent claudication in lumbar spinal canal stenosis.

SUMMARY OF BACKGROUND DATA

Neurogenic intermittent claudication has been known as a characteristic symptom of lumbar spinal canal stenosis (LSCS), but the pathogenesis is poorly understood. Venous stasis of cauda equina has been speculated as a possible factor in the development of symptoms of the lower extremities while walking. On the other hand, ectopic firing originating in the dorsal root ganglia is thought to play an important role in the development of radicular pain or abnormal sensation. However, a direct association between venous stasis and ectopic firing has been never demonstrated.

METHODS

Using 10 Wistar rats, the LSCS group was prepared by inserting two silicone strips into the L3 and L5 dorsal epidural spaces. Another 10 animals were treated without silicone insertion as a sham group. Fourteen days later, the ectopic firing originating in the L5 nerve root was antidromically recorded from the distal stump of the severed sural nerve. After recording initial spontaneous firing, the posterior vena cava was clamped for 60 seconds to simulate a transient venous stasis and the changes in firing were analyzed.

RESULTS

None of the animals in the sham group showed a significant change in firing due to venous stasis. In contrast, most animals in the LSCS group showed a marked increase in firing during the venous stasis with some latency and then returned to the initial firing state after the release of the clamp. This phenomenon was repeated as long as the animals were maintained.

CONCLUSIONS

We demonstrated that ectopic firing was elicited by venous stasis only in the LSCS animals. Therefore, the venous stasis may be a major factor of neurogenic intermittent claudication.

Narrowing of Lumbar Spinal Canal Predicts Chronic Low Back Pain More Accurately than Intervertebral Disc Degeneration: A Magnetic Resonance Imaging Study in Young Finnish Male Conscripts

The objective of this magnetic resonance imaging study was to evaluate the role of degenerative changes, developmental spinal stenosis, and compression of spinal nerve roots in chronic low back (CLBP) and radicular pain in Finnish conscripts. The degree of degeneration, protrusion, and herniation of the intervertebral discs and stenosis of the nerve root canals was evaluated, and the midsagittal diameter and cross-sectional area of the lumbar vertebrae canal were measured in 108 conscripts with CLBP and 90 asymptomatic controls. The midsagittal diameters at L1-L4 levels were significantly smaller in the patients with CLBP than in the controls. Moreover, degeneration of the L4/5 disc and protrusion or herniation of the L5/S1 disc and stenosis of the nerve root canals at level L5/S1 were more frequent among the CLBP patients. Multifactorial analysis of the magnetic resonance imaging findings provided a total explanatory rate of only 33%. Narrowing of the vertebral canal in the anteroposterior direction was more likely to produce CLBP and radiating pain than intervertebral disc degeneration or narrowing of the intervertebral nerve root canals.

Comparison of EQ-5D, HUI, and SF-36-derived societal health state values among spine patient outcomes research trial (SPORT) participants

PURPOSE

To compare societal values across health-state classification systems and to describe the performance of these systems at baseline in a large population of persons with confirmed diagnosis of intervertebral disc herniation (IDH), spinal stenosis (SpS), or degenerative spondylolisthesis (DS).

METHODS

We compared values for EQ-5D (York weights), HUI (Mark 2 and 3), SF-6D, and the SF-36-derived estimate of the Quality of Well Being (eQWB) score using signed rank tests. We tested each instrument's ability to discriminate between health categories and level of symptom satisfaction. Correlations were assessed with Spearman rank correlations. We evaluated ceiling and floor effects by comparing the proportion at the highest and the lowest possible score for each tool. In addition, we compared proportions at the highest and lowest levels by dimension. The number of unique health states assigned was compared across instruments. We calculated the difference between those who were very dissatisfied and all others.

RESULTS

Mean values ranged from 0.39 to 0.63 among 2097 participants ages 18-93 (mean age 53, 47% female) with significant differences in pair-wise comparisons noted for all systems. Correlations ranged from 0.30 to 0.78. Although all systems showed statistically significant differences in health state values when baseline comparisons were made between those who were very dissatisfied with their symptoms and those who were not, the magnitude of this difference ranged widely across systems. Mean differences (95% CI) between those very dissatisfied and all others were 0.30 (0.269, 0.329) for EQ-5D, 0.22 (0.190, 0.241) for HUI(3), 0.18 (0.161, 0.201) for HUI(2), 0.11 (0.095, 0.117) for SF-6D, 0.04 (0.039, 0.049) for eQWB, and 0.07 (0.056, 0.077) for VAS (with transformation applied to group means).

CONCLUSION

Differences in preference-weighted health state classification systems are evident at baseline in a population with confirmed IDH, SpS, and DS. Caution should be used when comparing health state values derived from various systems.

A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results

STUDY DESIGN

A randomized, controlled, prospective multicenter trial comparing the outcomes of neurogenic intermittent claudication (NIC) patients treated with the interspinous process decompression system (X STOP) with patients treated nonoperatively.

OBJECTIVE

To determine the safety and efficacy of the X STOP interspinous implant.

SUMMARY OF BACKGROUND DATA

Patients suffering from NIC secondary to lumbar spinal stenosis have been limited to a choice between nonoperative therapies and decompressive surgical procedures, with or without fusion. The X STOP was developed to provide an alternative therapeutic treatment. METHODS.: 191 patients were treated, 100 in the X STOP group and 91 in the control group. The primary outcomes measure was the Zurich Claudication Questionnaire, a patient-completed, validated instrument for NIC.

RESULTS

At every follow-up visit, X STOP patients had significantly better outcomes in each domain of the Zurich Claudication Questionnaire. At 2 years, the X STOP patients improved by 45.4% over the mean baseline Symptom Severity score compared with 7.4% in the control group; the mean improvement in the Physical Function domain was 44.3% in the X STOP group and -0.4% in the control group. In the X STOP group, 73.1% patients were satisfied with their treatment compared with 35.9% of control patients.

CONCLUSIONS

The X STOP provides a conservative yet effective treatment for patients suffering from lumbar spinal stenosis. In the continuum of treatment options, the X STOP offers an attractive alternative to both conservative care and decompressive surgery.

Evaluation of the changes in the muscle sympathetic nerve activity and anterior tibial muscle blood flow caused by the Valsalva maneuver in patients with lumbago and healthy subjects

Clinical symptoms affecting the lower extremities are common among lumber spinal disorder patients. Pain, numbness and sensory disturbance are major signs of these symptoms, and have been suggested to be related to sympathetic nerve disturbance. This study was designed to examine whether these patients experience a difference in sympathetic nerve flow in terms of muscle sympathetic nerve activity (MSA) compared to healthy subjects. Five patients with lumbar intervertebral disc herniation of the spine (LIDH) and four patients with lumbar spinal canal stenosis (LSCS) were examined along with six healthy volunteers. Basic MSAs for IDH and SCS patients that were introduced from a common peroneal nerve were found to be statistically higher than those of the control subjects. MSA behavior and muscle blood flow introduced from the tibialis anterior muscle over 30 seconds while performing the Valsalva maneuver, a well-known technique used to artificially facilitate MSA, were examined for all subjects, and showed relatively slower changes for LIDH and LSCS patients compared to the normal subjects. Muscle blood flow was inversely proportional to MSA for the normal subjects, and this relationship was observed for IDH patients as well as SCS patients. However, MSA and the muscle blood flow of patients gradually changed while performing the Valsalva maneuver relative to the control subjects. This suggests that the systemic physiological response to the maneuver is maintained, but that, some local modification mechanisms exist.

Can laminoplasty maintain the cervical alignment even when the C2 lamina is contained?

STUDY DESIGN

Retrospective case-controlled study of cervical laminoplasty.

OBJECTIVE

To evaluate the alignment and clinical result by laminoplasty when the C2 lamina is contained or retained.

SUMMARY OF BACKGROUND DATA

Resection of the C2 lamina was reported to progress to kyphosis after laminectomy. Laminoplasty was reported to inhibit kyphosis. But no study has ever shown if the alignment is retained when laminoplasty also included the C2 lamina.

METHODS

Seventy-two patients with cervical spondylotic myelopathy undergoing laminoplasty were analyzed. Follow-up averaged 4.0 years. The outcome was assessed by the Cobb angle between C2 and C7, and the motor function scores of the upper and lower extremities for cervical myelopathy were made by the Japanese Orthopedic Association. Patients were stratified into three groups depending on the handling of the C2 lamina: fully split (S group; n = 17), C2 dome-like laminotomy (D group; n = 19), and intact (I group; n = 36). Change of the C2-C7 angle was compared by the analysis of variance and post hoc test. The association between the alignment and the motor scores was analyzed.

RESULTS

Upper/lower score increased from 2.4/2.0 to 3.4/2.9, respectively. The C2-C7 angle decreased in S group: -8.3 degrees , D group: -5.2 degrees , and I group: -1.5 degrees . The cervical alignment deteriorated significantly in S group compared with the I group (P < 0.01). The C2-C7 angle change or postoperative C2-C7 angle had no significant correlation with the postoperative upper and lower m-JOA scores or score change.

CONCLUSIONS

Subaxial laminoplasty maintained the alignment. But if laminoplasty included the C2 lamina, the alignment worsened.

Acute traumatic central cord syndrome—experience using surgical decompression with open-door expansile cervical laminoplasty

BACKGROUND

Open-door expansile cervical laminoplasty (ODECL) is an effective surgical technique in the treatment of multilevel cervical spondylotic myelopathy. In the present study, we reviewed the safety and short-term neurological outcome after expansile cervical laminoplasty in the treatment of acute central cord syndrome.

METHODS

We retrospectively reviewed our database over a 3-year period (January 1997-January 2001) and identified 69 surgically treated cervical spinal cord injuries, including 29 cases of acute traumatic central cord syndrome (ATCCS). Fifteen of these patients underwent expansile cervical laminoplasty, whereas 14 did not because of radiographic evidence of sagittal instability. We collected data on the preoperative and the immediate postoperative and 3-month neurological examinations. Neurological function was assessed using the Asia Spinal Injury Association (ASIA) grading system. We also reviewed the occurrence of complications and short-term radiological stability after the index procedure.

RESULTS

The median age was 56 years. All patients had hyperextension injuries with underlying cervical spondylosis and stenosis in the absence of overt fracture or instability. The average delay from injury to surgery was 3 days. The preoperative ASIA grade scale was grade C, 8 patients, and grade D, 7 patients. There were no cases of immediate postoperative deterioration or at 3 months follow-up. Neurological outcome: 71.4% (10/14) of patients improved 1 ASIA grade when examined 3 months post injury.

CONCLUSIONS

Surgical intervention consisting of ODECL can be safely applied in the subset of patients with ATCCS without instability who have significant cervical spondylosis/stenosis. Open-door expansile cervical laminoplasty is a safe, low-morbidity, decompressive procedure, and in our patients did not produce neurological deterioration.

Insertion loads of the X STOP interspinous process distraction system designed to treat neurogenic intermittent claudication

An interspinous process implant has been developed to treat patients suffering from neurogenic intermittent claudication secondary to lumbar spinal stenosis. As most patients who suffer from spinal stenosis are over the age of 50 and may have weaker bones, it is imperative to know how bone mineral density (BMD) correlates with lateral spinous process strength. The study was undertaken to characterize the lateral failure loads of the spinous process, correlate the failure loads to BMD, and compare the failure loads to the loads required to insert an interspinous process implant. Spinous process lateral failure loads were assessed, correlated to BMD, and compared to the loads required to insert an interspinous process implant. Mean spinous process failure loads were significantly greater than the lateral insertion load of the interspinous process implant. There was a significant relationship between the BMD and spinous process failure load. The technique used to insert the interspinous implant poses little risk to spinous process failure. There is ample margin of safety between the insertion loads and spinous process failure loads. The significant relationship between BMD and spinous process failure load suggests that patients with lower BMD must be approached with more caution during the implant insertion procedure.

Rehabilitation of orthopedic and rheumatologic disorders. 5. Lumbar spinal stenosis

This self-directed learning module highlights the pathoanatomy and pathogenesis of lumbar spinal stenosis. The areas covered include assessment and therapeutic options in the rehabilitation of patients with degenerative lumbar spinal stenosis. It is part of the study guide on rehabilitation of orthopedic and rheumatologic disorders in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation.

OVERALL ARTICLE OBJECTIVES

(a) To summarize the evaluation and management of lumbar spinal stenosis and (b) to review the pathoanatomy and pathogenesis of lumbar degenerative spinal stenosis.

Long-term outcomes of surgical and nonsurgical management of lumbar spinal stenosis: 8 to 10 year results from the maine lumbar spine study

STUDY DESIGN

A prospective observational cohort study.

OBJECTIVE

To assess long-term outcomes of patients with lumbar spinal stenosis treated surgically or nonsurgically.

SUMMARY OF BACKGROUND DATA

The relative benefit of various treatments for lumbar spinal stenosis is uncertain. Surgical treatment has been associated with short-term improvement, but recurrence of symptoms has been documented. Few studies have compared long-term outcomes of surgical and nonsurgical treatments.

METHODS

Patients recruited from the practices of orthopaedic surgeons, neurosurgeons, and occupational medicine physicians throughout Maine had baseline interviews with follow-up questionnaires mailed at regular intervals over 10 years. Clinical data were obtained at baseline from a physician questionnaire. Most patients initially undergoing surgery had a laminectomy without fusion performed. Outcomes including patient-reported symptoms of leg and back pain, functional status, and satisfaction were assessed at 8- to 10-year follow-up. Primary analyses were based on initial treatment received with secondary analyses examining actual treatment received by 10 years.

RESULTS

Of 148 eligible consenting patients initially enrolled, 105 were alive after 10 years (67.7% survival rate). Among surviving patients, long-term follow-up between 8 and 10 years was available for 97 of 123 (79%) patients (including 11 patients who died before the 10-year follow-up but completed a 8 or 9 year survey); 56 of 63 (89%) initially treated surgically and 41 of 60 (68%) initially treated nonsurgically. Patients undergoing surgery had worse baseline symptoms and functional status than those initially treated nonsurgically. Outcomes at 1 and 4 years favored initial surgical treatment. After 8 to 10 years, a similar percentage of surgical and nonsurgical patients reported that their low back pain was improved(53% vs. 50%, P = 0.8), their predominant symptom (either back or leg pain) was improved (54% vs. 42%, P = 0.3), and they were satisfied with their current status (55% vs. 49%, P = 0.5). These treatment group findings persisted after adjustment for other determinants of outcome in multivariate models. However, patients initially treated surgically reported less severe leg pain symptoms and greater improvement in back-specific functional status after 8 to 10 years than nonsurgically treated patients. By 10 years, 23% of surgical patients had undergone at least one additional lumbar spine operation, and 39% of nonsurgical patients had at least one lumbar spine operation. Patients undergoing subsequent surgical procedures had worse outcomes than those continuing with their initial treatment. Outcomes according to actual treatment received at 10 years did not differ because individuals undergoing additional surgical procedures had worse outcomes than those continuing with their initial treatment.

CONCLUSIONS

Among patients with lumbar spinal stenosis completing 8- to 10-year follow-up, low back pain relief, predominant symptom improvement, and satisfaction with the current state were similar in patients initially treated surgically or nonsurgically. However, leg pain relief and greater back-related functional status continued to favor those initially receiving surgical treatment. These results support a shared decision-making approach among physicians and patients when considering treatment options for lumbar spinal stenosis.

The treatment mechanism of an interspinous process implant for lumbar neurogenic intermittent claudication

STUDY DESIGN

The spinal canal and neural foramina dimensions of cadaver lumbar spines were quantified during flexion and extension using magnetic resonance imaging before and after placement of an interspinous process implant.

OBJECTIVE

To quantify the effect of the implant on the dimensions of the spinal canal and neural foramina during flexion and extension.

SUMMARY OF THE BACKGROUND DATA

Lumbar neurogenic intermittent claudication symptoms are typically exacerbated during extension and relieved during flexion. It is understood that the dimensions of the spinal canal and neural foramen increase in flexion and decrease in extension. The authors hypothesized that an interspinous process implant would significantly prevent narrowing of the canal and foramina in extension and have no significant effect in flexion.

METHODS

Eight L2-L5 specimens were positioned to 15 degrees of flexion and 15 degrees of extension using a positioning frame. Each specimen was magnetic resonance imaged with and without an interspinous implant (X STOP) placed between the L3-L4 spinous processes. Canal and foramina dimensions were compared between the intact and implanted specimens using a repeated measures analysis of variance with a level of significance of 0.05.

RESULTS

In extension, the implant significantly increased the canal area by 18% (231-273 mm), the subarticular diameter by 50% (2.5-3.7 mm), the canal diameter by 10% (17.8-19.5 mm), the foraminal area by 25% (106-133 mm), and the foraminal width by 41% (3.4-4.8 mm).

CONCLUSIONS

The results of this study show that the X STOP interspinous process implant prevents narrowing of the spinal canal and foramina in extension.

Disability and walking capacity in patients with lumbar spinal stenosis: association with sensorimotor function, balance, and functional performance

STUDY DESIGN

One-group, prospective, cross-sectional study.

OBJECTIVES

To determine how sensorimotor function, balance, and physical performance are associated with disability and walking capacity in patients with lumbar spinal stenosis.

BACKGROUND

Disability and limited walking capacity are often reported by patients with lumbar spinal stenosis. Identification of associated factors could provide information for future investigations leading to better prevention and intervention strategies.

METHODS AND MEASURES

Fifty patients with lumbar spinal stenosis answered questions regarding symptom intensity, disability, and walking capacity. Muscle strength and vibration sense were assessed to represent sensorimotor function. Balance ability was measured by single-leg stance time and basic physical performance was tested by the up-and-go (UG) test. Regression analyses, entering demographics and symptom intensity as control variables, and sensory, strength, balance, and physical performance as additional independent variables, were conducted separately for disability and walking capacity.

RESULTS

Symptom intensity, vibration sense at the big toe, and UG test time were significantly correlated with disability. The final regression model showed that the control variables explained 20% of the variance, while vibration sense and UG test time explained an additional 20% of the variance. Walking capacity was significantly correlated with vibration sense at the big toe and UG test time. No significant regression model emerged for walking capacity.

CONCLUSIONS

A moderate amount of variance in disability could be explained by sensory function at the big toe and physical performance. These factors should be considered in future research.

Isolated blood–cerebrospinal fluid barrier dysfunction: prevalence and associated diseases

OBJECTIVE

An isolated dysfunction of the blood-CSF barrier is characterised by an abnormal elevation of the albumin CSF/serum concentration ratio (Q(alb)) without any other pathological CSF findings. Although common in routine CSF analysis, the clinical significance of an isolated barrier dysfunction frequently remains unclear. We examined neurological disorders associated with an isolated elevation of Q(alb) to identify possible determinants of blood-CSF barrier dysfunction.

METHODS

367 patients (124 women, 243 men, median age 60. 0 years) out of 3,873 patients receiving diagnostic lumbar puncture at the University Hospital of Ulm (Germany) showed an isolated dysfunction of the blood-CSF barrier. Clinical data as well as MRI findings of these patients were analysed.

RESULTS

Isolated barrier dysfunction occurred most frequently (> 30%) in Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), normal pressure hydrocephalus (NPH), lumbar spinal stenosis, and polyneuropathy (PNP). In patients who showed no other evidence of neurological disease, isolated barrier dysfunction was found in 14. 9% of cases. The extent of barrier dysfunction was most prominent in brain tumours, GBS, and CIDP. There was a significant correlation of Q(alb) with both weight and body mass index (BMI).

CONCLUSIONS

Although isolated barrier dysfunction may be found in a variety of neurological diseases, it is especially frequent in GBS, CIDP, NPH, spinal canal stenosis, and PNP. In these patients, disease-related mechanisms contributing to barrier dysfunction are likely. Moreover, barrier function seems to be influenced by disease-independent determinants like weight and BMI.

Evaluation of circulatory compromise in the leg in lumbar spinal canal stenosis

To evaluate whether hemoglobin oxygen saturation and hemoglobin concentration of the leg are useful indicators for circulatory compromise in patients with lumbar spinal canal stenosis, we investigated the changes in the indices during level gait using reflectance spectrophotometry. Thirty-three patients with lumbar spinal stenosis were studied. Preoperatively, the hemoglobin oxygen saturation was greater in the 33 patients than in the control subjects. The indices increased in the control subjects more than those in the patients. Postoperatively, the increases in hemoglobin oxygen saturation were greater in the patients with lumbar spinal canal stenosis than before decompression and the hemoglobin concentration tended to approximate that in the control subjects. The results suggest these indices might be useful for monitoring disease severity in patients with lumber spinal canal stenosis. In addition to stenotic ischemia in the spinal canal, it is thought that the neurogenic intermittent claudication is secondarily caused by circulatory failure in the lower extremities attributable to the autonomic nervous dysfunction.

Central motor conduction in cervical dystonia with cervical spondylotic myelopathy

OBJECTIVES

It has been known that cervical dystonia develops secondarily to spinal cord injuries as secondary dystonia. However, little is known about the pathophysiological mechanism.

PATIENTS AND METHODS

We examined motor and sensory conduction in six patients with symptomatic cervical dystonia by transcranial magnetic stimulation (TMS). All of the patients exhibited unilateral head rotation. They had symptoms corresponding to cervical myelopathy and felt discomfort in the neck, shoulders or arms before involuntary movement occurred.

RESULTS

Although the overall central motor conduction time (CMCT) was not different from that of normal controls, contralateral CMCT was significantly delayed compared to ipsilateral CMCT (p<0.05). The results of somatosensory evoked potential study demonstrated that contralateral central conduction time (CCT) was not significantly different from ipsilateral CCT.

CONCLUSION

These findings indicate that there is a selective interference with the contralateral corticospinal tract in patients with symptomatic cervical dystonia.

Experience with cervical stenosis and temporary paralysis in athletes

Object. Transient spinal cord injury (TSCI) in athletes presents one of the most challenging clinical scenarios. Management difficulties in and subsequent return-to-play decisions are especially important in those with cervical canal stenosis.

Methods. Ten athletes (nine male and one female patients) were evaluated for TSCI. The diagnostic survey included physical and neurological examinations, plain radiographs with flexion—extension dynamic studies, computerized tomography, and magnetic resonance (MR) imaging. Clinical courses were followed and, in those who returned to contact sports activities, subsequent experience was noted.

Symptoms consisted of paralysis, weakness, or numbness in all four extremities, their duration ranging from 15 minutes to 48 hours. Radiography revealed no evidence of fracture/dislocation or ligamentous instability. Spinal stenosis of 8 to 13 mm in length at three or more levels was evident in all cases. Four patients returned to competition without recurrent TSCI (mean follow-up duration 40 months); six individuals retired.

The occurrence of TSCI is not uncommon in athletes involved in contact sports. The diagnostic workup focuses on excluding fracture/dislocation, cord contusion, ligamentous infolding or instability, herniated nucleus pulposus, syrinx, or other surgically correctable lesions. There appear to be two groups of athletes who sustain TSCI: those who experience TSCI yet in whom radiographic studies are normal, and those with cervical stenosis, the most difficult management group.

Conclusions. It does not appear that a single episode of TSCI in an athlete with spinal stenosis will substantially increase the risk of subsequent catastrophic spinal cord injury in those in whom MR imaging demonstrates preservation of cerebrospinal fluid signal.