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1.  Role of conventional lumbar myelography in the management of sciatica: An experience from Pakistan 
Asian Journal of Neurosurgery  2012;7(1):25-28.
A prospective study of 80 patients suffering from sciatica was conducted at Fauji Foundation Hospital, Rawalpindi, Pakistan.
The aim of this study was to select patients for lumbar myelography on clinical grounds in the absence of magnetic resonance imaging (MRI)/computerized tomography (CT) facilities and to know the causes of sciatica.
Materials and Methods:
All patients underwent conventional lumbar myelography due to lack of MRI facility at a local hospital as well as financial constraints. Myelography was done with radio-opaque dye, Iopamidol, on outpatient basis
Lumbar myelograms were positive in 77.5% and negative in 22.5% cases. Minor complications in the form of headache developed in 32.5% patients but no major complication like meningitis and archnoiditis developed. Lumbar disc prolapse and stenosis were found to be common causes of sciatica. Non-filling of nerve roots was seen in 33.87%, blocks (complete/partial) in 54.83%, and stenosis in 11.29% patients.
Conventional myelography was found to be safe and an informative diagnostic technique in areas where facility of high-tech investigations like CT/MRI was not available. Conventional lumbar myelography could be recommended and performed with confidence on outdoor basis, in cases of sciatica with positive straight leg raising test, reflex loss, sensory, or motor deficit.
PMCID: PMC3358954  PMID: 22639688
Complications; iopamidol; lumbar disc; myelography; sciatica
2.  Comparative Study of Lumbar Magnetic Resonance Imaging and Myelography in Young Soldiers with Herniated Lumbar Disc 
This study was undertaken to compare the diagnostic performances of magnetic resonance imaging (MRI), MR myelography (MRM) and myelography in young soldiers with a herniated lumbar disc (HLD).
Sixty-five male soldiers with HLD comprised the study cohort. A visual analogue scale for low back pain (VAS-LBP), VAS for leg radiating pain (VAS-LP), and Oswestry disability index (ODI) were applied. Lumbar MR, MRM, and myelographic findings were checked and evaluated by four independent radiologists, respectively. Each radiologist was asked to score (1 to 5) the degree of disc protrusion and nerve root compression using modified grading systems devised by the North American Spine Society and Pfirrmann and the physical examination rules for conscription in the Republic of Korea. Correlated coefficients between clinical and radiological factors were calculated. Interpretational reproducibility between MRI and myelography by four bases were calculated and compared.
Mean patient age was 20.5 ± 1.1. Mean VAS-LBP and VAS-LP were 6.7 ± 1.6 and 7.4 ± 1.7, respectively. Mean ODI was 48.0 ± 16.2%. Mean MRI, MRM, and myelography scores were 3.3 ± 0.9, 3.5 ± 1.0, and 3.9 ± 1.1, respectively. All scores of diagnostic performances were significantly correlated (p < 0.05). However, none of these scores reflected the severity of patients' symptoms. There was no statistical difference of interpretational reproducibility between MRI and myelography.
Although MRI and myelography are based on different principles, they produce similar interpretational reproducibility in young soldiers with a HLD. However, these modalities do not reflect the severity of symptoms.
PMCID: PMC3053544  PMID: 21430976
Comparison study; Herniated Lumbar Disc; Interpretational reproducibility; Magnetic Resonance Imaging; MR Myelography; Myelography
3.  Artificial Discs for Lumbar and Cervical Degenerative Disc Disease –Update 
Executive Summary
To assess the safety and efficacy of artificial disc replacement (ADR) technology for degenerative disc disease (DDD).
Clinical Need
Degenerative disc disease is the term used to describe the deterioration of 1 or more intervertebral discs of the spine. The prevalence of DDD is roughly described in proportion to age such that 40% of people aged 40 years have DDD, increasing to 80% among those aged 80 years or older. Low back pain is a common symptom of lumbar DDD; neck and arm pain are common symptoms of cervical DDD. Nonsurgical treatments can be used to relieve pain and minimize disability associated with DDD. However, it is estimated that about 10% to 20% of people with lumbar DDD and up to 30% with cervical DDD will be unresponsive to nonsurgical treatments. In these cases, surgical treatment is considered. Spinal fusion (arthrodesis) is the process of fusing or joining 2 bones and is considered the surgical gold standard for DDD.
Artificial disc replacement is the replacement of the degenerated intervertebral disc with an artificial disc in people with DDD of the lumbar or cervical spine that has been unresponsive to nonsurgical treatments for at least 6 months. Unlike spinal fusion, ADR preserves movement of the spine, which is thought to reduce or prevent the development of adjacent segment degeneration. Additionally, a bone graft is not required for ADR, and this alleviates complications, including bone graft donor site pain and pseudoarthrosis. It is estimated that about 5% of patients who require surgery for DDD will be candidates for ADR.
Review Strategy
The Medical Advisory Secretariat conducted a computerized search of the literature published between 2003 and September 2005 to answer the following questions:
What is the effectiveness of ADR in people with DDD of the lumbar or cervical regions of the spine compared with spinal fusion surgery?
Does an artificial disc reduce the incidence of adjacent segment degeneration (ASD) compared with spinal fusion?
What is the rate of major complications (device failure, reoperation) with artificial discs compared with surgical spinal fusion?
One reviewer evaluated the internal validity of the primary studies using the criteria outlined in the Cochrane Musculoskeletal Injuries Group Quality Assessment Tool. The quality of concealment allocation was rated as: A, clearly yes; B, unclear; or C, clearly no. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the overall quality of the body of evidence (defined as 1 or more studies) supporting the research questions explored in this systematic review. A random effects model meta-analysis was conducted when data were available from 2 or more randomized controlled trials (RCTs) and when there was no statistical and or clinical heterogeneity among studies. Bayesian analyses were undertaken to do the following:
Examine the influence of missing data on clinical success rates;
Compute the probability that artificial discs were superior to spinal fusion (on the basis of clinical success rates);
Examine whether the results were sensitive to the choice of noninferiority margin.
Summary of Findings
The literature search yielded 140 citations. Of these, 1 Cochrane systematic review, 1 RCT, and 10 case series were included in this review. Unpublished data from an RCT reported in the grey literature were obtained from the manufacturer of the device. The search also yielded 8 health technology assessments evaluating ADR that are also included in this review.
Six of the 8 health technology assessments concluded that there is insufficient evidence to support the use of either lumbar or cervical ADR. The results of the remaining 2 assessments (one each for lumbar and cervical ADR) led to a National Institute for Clinical Excellence guidance document supporting the safety and effectiveness of lumbar and cervical ADR with the proviso that an ongoing audit of all clinical outcomes be undertaken owing to a lack of long-term outcome data from clinical trials.
Regarding lumbar ADR, data were available from 2 noninferiority RCTs to complete a meta-analysis. The following clinical, health systems, and adverse event outcome measures were synthesized: primary outcome of clinical success, Oswestry Disability Index (ODI) scores, pain VAS scores, patient satisfaction, duration of surgery, amount of blood loss, length of hospital stay, rate of device failure, and rate of reoperation.
The meta-analysis of overall clinical success supported the noninferiority of lumbar ADR compared with spinal fusion at 24-month follow-up. Of the remaining clinical outcome measures (ODI, pain VAS scores, SF-36 scores [mental and physical components], patient satisfaction, and return to work status), only patient satisfaction and scores on the physical component scale of the SF-36 questionnaire were significantly improved in favour of lumbar ADR compared with spinal fusion at 24 months follow-up. Blood loss and surgical time showed statistical heterogeneity; therefore, meta-analysis results are not interpretable. Length of hospital stay was significantly shorter in patients receiving the ADR compared with controls. Neither the number of device failures nor the number of neurological complications at 24 months was statistically significantly different between the ADR and fusion treatment groups. However, there was a trend towards fewer neurological complications at 24 months in the ADR treatment group compared with the spinal fusion treatment group.
Results of the Bayesian analyses indicated that the influence of missing data on the outcome measure of clinical success was minimal. The Bayesian model indicated that the probability for ADR being better than spinal fusion was 79%. The probability of ADR being noninferior to spinal fusion using a -10% noninferiority bound was 92%, and using a -15% noninferiority bound was 94%. The probability of artificial discs being superior to spinal fusion in a future trial was 73%.
Six case series were reviewed, mainly to characterize the rate of major complications for lumbar ADR. The Medical Advisory Secretariat defined a major complication as any reoperation; device failure necessitating a revision, removal or reoperation; or life-threatening event. The rates of major complications ranged from 0% to 13% per device implanted. Only 1 study reported the rate of ASD, which was detected in 2 (2%) of the 100 people 11 years after surgery.
There were no RCT data available for cervical ADR; therefore, data from 4 case series were reviewed for evidence of effectiveness and safety. Because data were sparse, the effectiveness of cervical ADR compared with spinal fusion cannot be determined at this time.
The rate of major complications was assessed up to 2 years after surgery. It was found to range from 0% to 8.1% per device implanted. The rate of ASD is not reported in the clinical trial literature.
The total cost of a lumbar ADR procedure is $15,371 (Cdn; including costs related to the device, physician, and procedure). The total cost of a lumbar fusion surgery procedure is $11,311 (Cdn; including physicians’ and procedural costs).
Lumbar Artificial Disc Replacement
Since the 2004 Medical Advisory Secretariat health technology policy assessment, data from 2 RCTs and 6 case series assessing the effectiveness and adverse events profile of lumbar ADR to treat DDD has become available. The GRADE quality of this evidence is moderate for effectiveness and for short-term (2-year follow-up) complications; it is very low for ASD.
The effectiveness of lumbar ADR is not inferior to that of spinal fusion for the treatment of lumbar DDD. The rates for device failure and neurological complications 2 years after surgery did not differ between ADR and fusion patients. Based on a Bayesian meta-analysis, lumbar ADR is 79% superior to lumbar spinal fusion.
The rate of major complications after lumbar ADR is between 0% and 13% per device implanted. The rate of ASD in 1 case series was 2% over an 11-year follow-up period.
Outcome data for lumbar ADR beyond a 2-year follow-up are not yet available.
Cervical Artificial Disc Replacement
Since the 2004 Medical Advisory Secretariat health technology policy assessment, 4 case series have been added to the body of evidence assessing the effectiveness and adverse events profile of cervical ADR to treat DDD. The GRADE quality of this evidence is very low for effectiveness as well as for the adverse events profile. Sparse outcome data are available.
Because data are sparse, the effectiveness of cervical ADR compared with spinal fusion cannot be determined at this time.
The rate of major complications was assessed up to 2 years after surgery; it ranged from 0% to 8.1% per device implanted. The rate of ASD is not reported in the clinical trial literature.
PMCID: PMC3379529  PMID: 23074480
California Medicine  1959;91(2):65-67.
In a study of 59 patients surgically treated by various surgeons for relief of herniated lumbar intervertebral disc accompanied by symptoms that persistently recurred or had become resistant to conservative therapy, it was noted from review of hospital and office records that laminectomy either greatly relieved or entirely abated symptoms in 83 per cent of the cases.
Postoperative complications reported by the surgeons who did the operations consisted of one death and five wound infections. Contrast myelography and electromyography, used in almost all cases in the series, appeared to be valuable adjuncts in the diagnosis of herniated lumbar intervertebral discs. The most common site of the lesion in this series was between the fourth and fifth lumbar vertebrae. Strain upon lifting was the most commonly reported precipitating factor.
PMCID: PMC1577908  PMID: 13671357
5.  A blast from the past!: The value of adding single slice magnetic resonance myelography sequence to magnetic resonance imaging of the spine; a flashback to the conventional myelography of the past 
Surgical Neurology International  2014;5(Suppl 15):S523-S528.
The study was undertaken to determine whether a single slice magnetic resonance (MR) myelogram sequence improves the interpretation and diagnostic yield for magnetic resonance imaging (MRI) of the spine.
A total of 100 cases with positive findings were retrospectively reviewed. All patients had initial imaging with sagittal T1-weighted (T1-W) and T2-weighted (T2-W) scans, followed by axial T2-W images. Subsequently, a heavily T2-W single slice MR myelogram sequence was acquired in coronal and sagittal planes. The MR myelogram images were evaluated initially by a radiologist, and, further independently reviewed, by a neurologist, neurosurgeon, and spine surgeon. The utility of the MR myelogram in establishing the diagnosis was graded on a 4-point scale.
Out of 100 cases, 53% showed degenerative spine or disc disease, 14% space occupying lesions, 13%, congenital lesions, 7% infection, and 7% other conditions. The MR myelogram contributed additional information in 50-74% cases. The intraclass correlation coefficient showed overall good agreement between observers in grading the utility of MR myelogram.
Single slice MR myelography is noninvasive avoiding the complications associated with lumbar punctures/intrathecal contrast injections, while image acquisition takes only an added 6-8 s. Although MR myelogram has no value as a stand-alone sequence, its inherent advantage is that it completes the overview of the spinal pathology in entirety, and adds vital three-dimensional information in 50-74% of cases.
PMCID: PMC4287895  PMID: 25593771
Magnetic resonance imaging; magnetic resonance myelography; myelogram; spine
6.  Pathophysiology of primary spinal syringomyelia 
Journal of neurosurgery. Spine  2012;17(5):367-380.
The pathogenesis of syringomyelia in patients with an associated spinal lesion is incompletely understood. The authors hypothesized that in primary spinal syringomyelia, a subarachnoid block effectively shortens the length of the spinal subarachnoid space (SAS), reducing compliance and the ability of the spinal theca to dampen the subarachnoid CSF pressure waves produced by brain expansion during cardiac systole. This creates exaggerated spinal subarachnoid pressure waves during every heartbeat that act on the spinal cord above the block to drive CSF into the spinal cord and create a syrinx. After a syrinx is formed, enlarged subarachnoid pressure waves compress the external surface of the spinal cord, propel the syrinx fluid, and promote syrinx progression.
To elucidate the pathophysiology, the authors prospectively studied 36 adult patients with spinal lesions obstructing the spinal SAS. Testing before surgery included clinical examination; evaluation of anatomy on T1-weighted MRI; measurement of lumbar and cervical subarachnoid mean and pulse pressures at rest, during Valsalva maneuver, during jugular compression, and after removal of CSF (CSF compliance measurement); and evaluation with CT myelography. During surgery, pressure measurements from the SAS above the level of the lesion and the lumbar intrathecal space below the lesion were obtained, and cardiac-gated ultrasonography was performed. One week after surgery, CT myelography was repeated. Three months after surgery, clinical examination, T1-weighted MRI, and CSF pressure recordings (cervical and lumbar) were repeated. Clinical examination and MRI studies were repeated annually thereafter. Findings in patients were compared with those obtained in a group of 18 healthy individuals who had already undergone T1-weighted MRI, cine MRI, and cervical and lumbar subarachnoid pressure testing.
In syringomyelia patients compared with healthy volunteers, cervical subarachnoid pulse pressure was increased (2.7 ± 1.2 vs 1.6 ± 0.6 mm Hg, respectively; p = 0.004), pressure transmission to the thecal sac below the block was reduced, and spinal CSF compliance was decreased. Intraoperative ultrasonography confirmed that pulse pressure waves compressed the outer surface of the spinal cord superior to regions of obstruction of the subarachnoid space.
These findings are consistent with the theory that a spinal subarachnoid block increases spinal subarachnoid pulse pressure above the block, producing a pressure differential across the obstructed segment of the SAS, which results in syrinx formation and progression. These findings are similar to the results of the authors' previous studies that examined the pathophysiology of syringomyelia associated with obstruction of the SAS at the foramen magnum in the Chiari Type I malformation and indicate that a common mechanism, rather than different, separate mechanisms, underlies syrinx formation in these two entities. Clinical trial registration no.: NCT00011245. (
PMCID: PMC3787878  PMID: 22958075
syringomyelia; physiology; ultrasonography; surgery; cerebrospinal fluid; magnetic resonance imaging; myelography
7.  Spine imaging after lumbar disc replacement: pitfalls and current recommendations 
Most lumbar artificial discs are still composed of stainless steel alloys, which prevents adequate postoperative diagnostic imaging of the operated region when using magnetic resonance imaging (MRI). Thus patients with postoperative radicular symptoms or claudication after stainless steel implants often require alternative diagnostic procedures.
Possible complications of lumbar total disc replacement (TDR) are reviewed from the available literature and imaging recommendations given with regard to implant type. Two illustrative cases are presented in figures.
Access-related complications, infections, implant wear, loosening or fracture, polyethylene inlay dislodgement, facet joint hypertrophy, central stenosis, and ankylosis of the operated segment can be visualised both in titanium and stainless steel implants, but require different imaging modalities due to magnetic artifacts in MRI.
Alternative radiographic procedures should be considered when evaluating patients following TDR. Postoperative complications following lumbar TDR including spinal stenosis causing radiculopathy and implant loosening can be visualised by myelography and radionucleotide techniques as an adjunct to plain film radiographs. Even in the presence of massive stainless steel TDR implants lumbar radicular stenosis and implant loosening can be visualised if myelography and radionuclide techniques are applied.
PMCID: PMC2716308  PMID: 19619332
8.  Conjoined lumbosacral nerve roots: current aspects of diagnosis 
European Spine Journal  2003;13(2):147-151.
Conjoined lumbosacral nerve roots (CLNR) are the most common anomalies involving the lumbar nerve structures which can be one of the origins of failed back syndromes. They can cause sciatica even without the presence of a additional compressive impingement (such as disc herniation, spondylolisthesis or lateral recess stenosis), and often congenital lumbosacral spine anomalies (such as bony defects) are present at the “conjoined sheaths”. This congenital anomaly has been reported in 14% of cadaver studies, but myelographic or computed tomographic studies have revealed an incidence of approximately 4% only. Diagnostic methods such as magnetic resonance imaging (MRI) are helpful for determination of the exact anatomical relations in this context. We present five typical cases of conjoined nerve roots observed during a 1 year period, equivalent to 6% of our out-patients without a history of surgical treatment on the lumbar spine. In all cases with suspicious radiological findings MRI or lumbar myelography combined with CT and multiplanar reconstructions is recommended.
PMCID: PMC3476574  PMID: 14634853
Conjoined nerve roots; MRI; Lumbosacral spine anomaly; Sciatica
9.  Magnetic resonance myelography in early postoperative lumbar discectomy: An efficient and cost effective modality 
Indian Journal of Orthopaedics  2010;44(3):257-262.
Magnetic resonance myelography (MRM) after lumbar discectomy is all too often an unrewarding challenge. A constellation of findings are inevitable, and determining their significance is often difficult. MRM is a noninvasive technique that can provide anatomical information about the subarachnoid space. Until now, there is no study reported in literature showing any clinico-radiological correlation of post operative MRM. The objective of this study was to prospectively evaluate the diagnostic effectiveness of MRM for the demonstration of decompression in operated discectomy patients and its correlation with subjective and objective outcome (pain and SLR) in immediate postoperative period.
Materials and Methods:
Fifty three patients of single level lumbar disc herniation (LDH) justifying the inclusion criteria were operated for discectomy. All patients underwent MRM on second/third postoperative day. The pain relief and straight leg raise sign improvement was correlated with the postoperative MRM images to group the patients into: A- Subjective Pain relief, SLR improved and MRM image showing myelo regression; B- Subjective Pain relief, SLR improved and MRM image showing no myelo regression; C- No Subjective Pain relief, no SLR improved and MRM image showing myelo regression and; D- No Subjective Pain relief, no SLR improved and MRM image showing no myelo regression.
The result showed that Group A had 46 while Group B, C and Group D had 4, 2 and one patients respectively. Clinico-radiological correlation (Clinically diagnosed patient and findings with MRM correlation) was present in 47 patients (88.68%) which includes both A and D groups. The MRM specificity and sensitivity were 92% and 33.33% respectively.
MRM is a non-invasive, efficient and reliable tool in confirming postoperative decompression in lumbar discectomy patients, especially when economic factors are to be considered and the required expertise to reliably read a complex confusing post-operative MRI is not available readily. Further, controlled double blinded multicentric study in operated and non operated LDH, with MRI comparison would give better evidence to justify its use in screening to detect persisting compression and to document decompression.
PMCID: PMC2911924  PMID: 20697477
Discectomy; lumbar disc herniation; magnetic resonance myelography
10.  Computerized tomography myelography with coronal and oblique coronal view for diagnosis of nerve root avulsion in brachial plexus injury 
The authors describe a new computerized tomography (CT) myelography technique with coronal and oblique coronal view to demonstrate the status of the cervical nerve rootlets involved in brachial plexus injury. They discuss the value of this technique for diagnosis of nerve root avulsion compared with CT myelography with axial view.
CT myelography was performed with penetration of the cervical subarachnoid space by the contrast medium. Then the coronal and oblique coronal reconstructions were created. The results of CT myelography were evaluated and classified with presence of pseudomeningocele, intradural ventral nerve rootlets, and intradural dorsal nerve rootlets. The diagnosis was by extraspinal surgical exploration with or without spinal evoked potential measurements and choline acetyl transferase activity measurement in 25 patients and recovery by a natural course in 3 patients. Its diagnostic accuracy was compared with that of CT myelography with axial view, correlated with surgical findings or a natural course in 57 cervical roots in 28 patients.
Coronal and oblique coronal views were superior to axial views in visualization of the rootlets and orientation of the exact level of the root. Sensitivity and specificity for coronal and oblique coronal views of unrecognition of intradural ventral and dorsal nerve root shadow without pseudomeningocele in determining pre-ganglionic injury were 100% and 96%, respectively. There was no statistically significant difference between coronal and oblique coronal views and axial views.
The information by the coronal and oblique coronal slice CT myelography enabled the authors to assess the rootlets of the brachial plexus and provided valuable data for helping to decide whether to proceed with exploration, nerve repair, primary reconstruction.
PMCID: PMC1947985  PMID: 17651476
11.  Are Spinal or Paraspinal Anatomic Markers Helpful for Vertebral Numbering and Diagnosing Lumbosacral Transitional Vertebrae? 
Korean Journal of Radiology  2014;15(2):258-266.
To evaluate the value of spinal and paraspinal anatomic markers in both the diagnosis of lumbosacral transitional vertebrae (LSTVs) and identification of vertebral levels on lumbar MRI.
Materials and Methods
Lumbar MRI from 1049 adult patients were studied. By comparing with the whole-spine localizer, the diagnostic errors in numbering vertebral segments on lumbar MRI were evaluated. The morphology of S1-2 disc, L5 and S1 body, and lumbar spinous processes (SPs) were evaluated by using sagittal MRI. The positions of right renal artery (RRA), superior mesenteric artery, aortic bifurcation (AB) and conus medullaris (CM) were described.
The diagnostic error for evaluation of vertebral segmentation on lumbar MRI alone was 14.1%. In lumbarization, all patients revealed a well-formed S1-2 disc with squared S1 body. A rhombus-shaped L5 body in sacralization and a rectangular-shaped S1 body in lumbarization were found. The L3 had the longest SP. The most common sites of spinal and paraspinal structures were: RRA at L1 body (53.6%) and L1-2 disc (34.1%), superior mesenteric artery at L1 body (55.1%) and T12-L1 disc (31.6%), and AB at L4 body (71.1%). CM had variable locations, changing from the T12-L1 disc to L2 body. They were located at higher sacralization and lower lumbarization.
The spinal morphologic features and locations of the spinal and paraspinal structures on lumbar MRI are not completely reliable for the diagnosis of LSTVs and identification on the vertebral levels.
PMCID: PMC3955794  PMID: 24644411
Spine; Lumbosacral vertebrae; Transitional vertebrae; MRI
12.  An increase in height of spinous process is associated with decreased heights of intervertebral disc and vertebral body in the degenerative process of lumbar spine 
European Spine Journal  2013;22(9):2030-2034.
Currently degeneration of the intervertebral disc and joint in the degenerative process of the lumbar spine has mainly attracted the attention, however, there are very few literatures focusing on the height of the spinous process. Our objective was to examine in what generation the change in spinous process height occurs and how the change is involved in the degenerative process of the lumbar spine.
CT or CT myelography of 1,015 patients, 536 males and 579 females were measured in 6 items, including the heights of the L4 and L5 vertebral bodies, the L4 and L5 spinous processes, the L4/5 intervertebral disc, and the L5/S1 intervertebral disc. All data of the 6 items were analyzed and compared between gender in 5 age groups (40s, 50s, 60s, 70s and 80s).
The results indicated a significant increase in the height of the L4 and L5 spinous process (P < 0.01) in the 60- to 70-year-old group for both genders, and also showed that the L4 and L5 vertebral body height was significantly decreased in the 50- to 60-year-old group (P < 0.01 in males, P < 0.001 in females).
Changes in the spinous process morphology followed degenerative changes of the intervertebral disc and vertebral body in the degenerative process of the lumbar spine. This result may suggest that the morphological change of an increase in the height of the spinous process may be a kind of biological defense reaction to stabilize the intervertebral portion.
PMCID: PMC3777063  PMID: 23546689
Lumbar spine; Degeneration; Spinous process; Vertebral body; Intervertebral disc
13.  Total disc replacement arthroplasty using the AcroFlex lumbar disc: a non-human primate model 
European Spine Journal  2002;11(Suppl 2):S115-S123.
Using a non-human primate model, the current study was undertaken to investigate the efficacy of the AcroFlex lumbar disc as an intervertebral disc prosthesis, based on biomechanical, histopathologic and histomorphometric analyses. A total of 20 mature male baboons (Papio cynocephalus, mean weight 30 kg) were randomized into two equal groups based on post-operative time periods of 6 (n=10) and 12 months (n=10). Each animal underwent an anterior transperitoneal surgical approach to the lumbar spine, with intervertebral reconstructions performed at L3-L4 and L5-L6 using the following techniques: (1) tricortical iliac autograft and (2) AcroFlex lumbar disc. The two treatments were equally randomized between the non-contiguous operative lumbar levels. Post-mortem analysis included histopathologic assessment of the systemic reticuloendothelial tissues, multi-directional flexibility testing of the operative functional spinal units and quantitative histological analysis of trabecular bone coverage at the prosthesis endplates. Data were statistically compared using a one-way ANOVA with the Student-Newman-Keuls test. All animals survived the operative procedure and post-operative interval without significant intra- or peri-operative complications. Histopathologic analysis of the paraffin-embedded systemic reticuloendothelial tissues indicated no significant pathologic changes at the 6- or 12-month intervals. Plain film radiographic analysis showed no lucencies or loosening of any prosthetic vertebral endplate. Biomechanical testing of the 6-month autograft, reconstructions with AcroFlex lumbar disc and non-operative control (n=10) intact motion segments indicated no significant differences in peak range of motion (ROM) in axial compression. However, axial rotation produced significantly lower ROM for the autograft treatment compared to the intact and AcroFlex groups (P<0.05). The most significant differences in peak ROM were noted between all treatment groups under flexion/extension and lateral bending loading modalities (P<0.05). By 12 months, the intact condition indicated significantly more motion in all bending modes compared to the AcroFlex and autograft treatments, which were not statistically different from each other (P>0.05). Gross histopathologic analysis of the AcroFlex disc prosthesis demonstrated excellent ingrowth at the level of the implant-bone interface, without evidence of fibrous tissue or synovium. BioQuant histomorphometric analysis at the metal-bone interface (bone contact area/total endplate area) indicated the mean ingrowth was 54.59±13.24% at 6 months and 56.79±5.85% at 12 months. Radiographic analysis showed no lucencies or loosening of the AcroFlex vertebral endplate. Based on multi-directional flexibility testing, motion was preserved in axial rotation, but significantly diminished in the other bending modalities, particularly at the 12-month interval. This effect may be secondary to the limited surface area of device-vertebral endplate contact. Histomorphometric analysis of porous ingrowth coverage at the vertebral bone-metal interface was more favorable for total disc arthroplasty compared to historical reports of cementless femoral components. This project serves as the first comprehensive in vivo investigation into the AcroFlex disc prosthesis, and establishes an excellent research model in the evaluation of total disc replacement arthroplasty.
PMCID: PMC3611574  PMID: 12384732
Total disc replacement arthroplasty Animal model Biomechanics Histomorphometry Porous ingrowth
14.  A prospective audit of the use and costs of myelography in a regional neuroscience unit. 
A consecutive series of 397 myelograms performed in 385 patients over a six month period at the Mersey Regional Neurosciences Unit is reported. The reasons for performing the myelogram were to identify the cause of a radicular lesion in 54% of patients, a chronic spinal cord lesion in 30%, an acute cord lesion in 9%, suspected disease at the level of the foramen magnum 6%, and for a variety of other conditions in 8%. For the 385 patients undergoing a myelogram in the study period, the median interval from admission to request, request to myelography and from myelography to discharge was nought, one and three days respectively. The proportion of patients submitted to myelography by individual consultants ranged from 7% to 28%. There was a two-fold variation in the delays in the time to requesting and performing myelograms. There was room for improvement in the clinical information supplied on the myelography request form. The role of ancillary investigations and their effect on myelography was unclear. Only 16 of the patients with suspected cord disease had visual evoked responses performed before myelography. Five of them had myelography after an abnormal result. The estimated annual direct cost of myelography in the unit was at least 486,000 pounds. Reorganisation might have yielded hypothetical "savings" of between 30,000 pounds (6%) and 155,000 pounds (32%), though in practical terms these "savings" represented resources which might have been freed for use in other higher priority clinical problems within the unit, rather than true reductions in monetary cost.
PMCID: PMC1031744  PMID: 2795078
15.  Post-myelography paraplegia in a woman with thoracic stenosis 
Myelography is a commonly performed diagnostic test used to assess spine pathology. Complications are unusual and usually self-limited. We report a rare case of transient paraplegia following myelography in a woman with thoracic stenosis.
A 51-year-old woman, 20 months status post-thoracic laminectomy, presented with progressive lower extremity weakness. The patient underwent myelography and post-myelography CT, and became paraplegic after the lumbar injection. Intravenous steroids were administered and a lumbar puncture was performed. The patient's neurologic function returned to baseline over the next 96 hours.
Conclusion and clinical relevance
Myelography is generally a safe procedure, but on rare occasions serious complications can arise. Therapeutic maneuvers may be helpful in reversing neurologic deficit.
PMCID: PMC3654453  PMID: 23809597
Myelopathy complication; Diagnostic imaging; Paraparesis; Paraplegia; Spinal stenosis; Thoracic vertebrae; Ossification of the posterior longitudinal ligament; Laminectomy
16.  The results of surgery for low back and leg pain due to presumptive prolapsed intervertebral disc 
Postgraduate Medical Journal  1971;47(544):120-128.
Fifty-six patients who had undergone fifty-seven operations for low back and leg pain thought to be associated with a prolapsed intervertebral disc have been reviewed. Forty-two had only mild residual signs and symptoms or none at all.
The patients selected for surgery were those with intractable signs and symptoms which had not improved with conservative treatment, and some were chronic low back invalids.
Myelography is a desirable adjunct in some patients when localization or diagnosis is in doubt.
In addition to the forty-two patients who had a successful outcome, five patients were improved and five who eventually had recurrences were successful at first. The figures therefore show that some measure of relief resulted from fifty-two out of fifty-seven operations performed.
The results of operation for carefully selected patients with presumptive prolapsed lumbar intervertebral disc are good. The operation is expected to relieve leg pain but more than half the patients will continue to have some discomfort or paraesthesiae. More relief from backache occurs than might be expected in view of the pathology and nature of the surgical procedure.
Most patients can return to their former occupation even though arduous.
Those accustomed to wear low back supports for years are able to stop doing so after surgery.
A small proportion of patients with initial successful results develop recurrence of back and leg symptoms. Most subside with conservative treatment and may arise from rupture of adhesions but re-exploration is sometimes necessary.
The results after the fenestration operation were not convincingly superior to those after laminectomy. Bearing in mind that the fenestration procedure was usually done on those with clear-cut signs and positive localization, it does not appear that there is anything to be gained by doing this rather more difficult operation.
PMCID: PMC2467165  PMID: 4252236
17.  Minimally invasive percutaneous transpedicular screw fixation: increased accuracy and reduced radiation exposure by means of a novel electromagnetic navigation system 
Acta Neurochirurgica  2010;153(3):589-596.
Minimally invasive percutaneous pedicle screw instrumentation methods may increase the need for intraoperative fluoroscopy, resulting in excessive radiation exposure for the patient, surgeon, and support staff. Electromagnetic field (EMF)-based navigation may aid more accurate placement of percutaneous pedicle screws while reducing fluoroscopic exposure. We compared the accuracy, time of insertion, and radiation exposure of EMF with traditional fluoroscopic percutaneous pedicle screw placement.
Minimally invasive pedicle screw placement in T8 to S1 pedicles of eight fresh-frozen human cadaveric torsos was guided with EMF or standard fluoroscopy. Set-up, insertion, and fluoroscopic times and radiation exposure and accuracy (measured with post-procedural computed tomography) were analyzed in each group.
Sixty-two pedicle screws were placed under fluoroscopic guidance and 60 under EMF guidance. Ideal trajectories were achieved more frequently with EMF over all segments (62.7% vs. 40%; p = 0.01). Greatest EMF accuracy was achieved in the lumbar spine, with significant improvements in both ideal trajectory and reduction of pedicle breaches over fluoroscopically guided placement (64.9% vs. 40%, p = 0.03, and 16.2% vs. 42.5%, p = 0.01, respectively). Fluoroscopy time was reduced 77% with the use of EMF (22 s vs. 5 s per level; p < 0.0001) over all spinal segments. Radiation exposure at the hand and body was reduced 60% (p = 0.058) and 32% (p = 0.073), respectively. Time for insertion did not vary between the two techniques.
Minimally invasive pedicle screw placement with the aid of EMF image guidance reduces fluoroscopy time and increases placement accuracy when compared with traditional fluoroscopic guidance while adding no additional time to the procedure.
PMCID: PMC3040822  PMID: 21153669
Minimally invasive; Electromagnetic field navigation; Pedicle screw; Fluoroscopy; Accuracy
18.  Which factors prognosticate rotational instability following lumbar laminectomy? 
European Spine Journal  2013;22(12):2897-2903.
Reduced strength and stiffness of lumbar spinal motion segments following laminectomy may lead to instability. Factors that predict shear biomechanical properties of the lumbar spine were previously published. The purpose of the present study was to predict spinal torsion biomechanical properties with and without laminectomy from a total of 21 imaging parameters.
Radiographs and MRI of ten human cadaveric lumbar spines (mean age 75.5, range 59–88 years) were obtained to quantify geometry and degeneration of the motion segments. Additionally, dual X-ray absorptiometry (DXA) scans were performed to measure bone mineral content and density. Facet-sparing lumbar laminectomy was performed either on L2 or L4. Spinal motion segments were dissected (L2–L3 and L4–L5) and tested in torsion, under 1,600 N axial compression. Torsion moment to failure (TMF), early torsion stiffness (ETS, at 20–40 % TMF) and late torsion stiffness (LTS, at 60–80 % TMF) were determined and bivariate correlations with all parameters were established. For dichotomized parameters, independent-sample t tests were used.
Univariate analyses showed that a range of geometric characteristics and disc and bone quality parameters were associated with torsion biomechanical properties of lumbar segments. Multivariate models showed that ETS, LTS and TMF could be predicted for segments without laminectomy (r2 values 0.693, 0.610 and 0.452, respectively) and with laminectomy (r2 values 0.952, 0.871 and 0.932, respectively), with DXA-derived measures of bone quality and quantity as the main predictors.
Vertebral bone content and geometry, i.e. intervertebral disc width, frontal area and facet joint tropism, were found to be strong predictors of ETS, LTS and TMF following laminectomy, suggesting that these variables could predict the possible development of post-operative rotational instability following lumbar laminectomy. Proposed diagnostic parameters might aid surgical decision-making when deciding upon the use of instrumentation techniques.
PMCID: PMC3843774  PMID: 24043337
Torsion biomechanics; Decompression; Laminectomy; Spinal stenosis and diagnostics
19.  Spinal perineurial and meningeal cysts 
Perineurial cysts may be responsible for clinical symptoms and a cure effected by their removal. They do not fill on initial myelography but may fill with Pantopaque some time, days or weeks, after Pantopaque has been instilled into the subarachnoid space. Perineurial cysts arise at the site of the posterior root ganglion. The cyst wall is composed of neural tissue. When initial myelography fails to reveal an adequate cause for the patient's symptoms and signs referable to the caudal nerve roots, then about a millilitre of Pantopaque should be left in the canal for delayed myelography which may later reveal a sacral perineurial cyst or, occasionally, a meningeal cyst. Meningeal diverticula occur proximal to the posterior root ganglia and usually fill on initial myelography. They are in free communication with the subarachnoid space and are rarely in my experience responsible for clinical symptoms. Meningeal diverticula and meningeal cysts appear to represent a continuum. Pantopaque left in the subarachnoid space may convert a meningeal diverticulum into an expanding symptomatic meningeal cyst, as in the case described. Many cases described as perineurial cysts represent abnormally long arachnoidal prolongations over nerve roots or meningeal diverticula. In general, neither of the latter is of pathological significance. Perineurial, like meningeal cysts and diverticula, may be asymptomatic. They should be operated upon only if they produce progressive or disabling symptoms or signs clearly attributable to them. When myelography must be done, and this should be done only as a preliminary to a probable necessary operation, then patient effort should be made to remove the Pantopaque.
PMCID: PMC493601  PMID: 5531903
20.  Midsagittal Anatomy of Lumbar Lordosis in Adult Egyptians: MRI Study 
Anatomy Research International  2014;2014:370852.
Despite the increasing recognition of the functional and clinical importance of lumbar lordosis, little is known about its description, particularly in Egypt. At the same time, magnetic resonance imaging (MRI) has been introduced as a noninvasive diagnostic technique. The aim of this study was to investigate the anatomy of the lumbar lordosis using midsagittal MRIs. Normal lumbar spine MRIs obtained from 93 individuals (46 males, 47 females; 25–57 years old) were evaluated retrospectively. The lumbar spine curvature and its segments “vertebrae and discs” were described and measured. The lumbar lordosis angle (LLA) was larger in females than in males. Its mean values increased by age. The lumbar height (LH) was longer in males than in females. At the same time, the lumbar breadth (LB) was higher in females than in males. Lumbar index (LI = LB/LH × 100) showed significant gender differences (P < 0.0001). Lordosis was formed by wedging of intervertebral discs and bodies of lower lumbar vertebrae. In conclusion, MRI might clearly reveal the anatomy of the lumbar lordosis. Use of LI in association with LLA could be useful in evaluation of lumbar lordosis.
PMCID: PMC4151604  PMID: 25210630
21.  Isolated septic facet joint arthritis as a rare cause of acute and chronic low back pain – a case report and literature review 
Polish Journal of Radiology  2012;77(4):72-76.
The most common cause of low back pain is degenerative disease of the intervertebral disc and other structures of the lumbar spine. However, in some cases other less frequent causes of such pain can be seen, for example septic facet joint arthritis. Until now, only 40 cases of such inflammatory changes within the spine have been reported in the literature. The disease is probably underestimated due to improper diagnostic pathway.
Case Report:
The authors describe a case of a 53-year-old woman who was repeatedly hospitalized during a five-month period because of an acute, severe low back pain, with sphincter dysfunction, partially resembling sciatic symptoms. Physical examinations revealed also focal tenderness in the area of the lumbar spine. Inflammatory markers (ESR – erythrocyte sedimentation rate, CRP – C-reactive protein) were elevated. Conservative analgetic treatment brought only partial and temporary relief of the pain and symptoms. The final accurate diagnosis of isolated septic facet joint arthritis at the level of L5/S1 was established after several months from the onset of the first symptoms, after performing various imaging examinations, including bone scintigraphy as well as CT and MRI of the lumbosacral spine. The patient fully recovered after antibiotic therapy and surgery, which was proven in several follow-up examinations showing no relevant pathology of the lumbar spine. The authors broadly describe the etiology and clinical symptoms of the septic facet joint arthritis as well as the significant role of imaging methods, especially MRI, in diagnostic process. The authors also discuss currently available treatment options, both conservative and surgical.
The diagnostic procedure of septic facet joint arthritis requires several steps to be taken. Establishing a correct diagnosis may be difficult, that is why it is important to remember about rare causes of low back pain and to perform detailed physical examination, laboratory tests and choose appropriate imaging techniques.
PMCID: PMC3529718  PMID: 23269942
low back pain; diagnostics; facet joint arthritis
22.  Lumbar Spine Intervertebral Disc Gene Delivery: A Pilot Study in Lewis Rats 
HSS Journal  2013;9(1):36-41.
Basic research toward understanding and treating disc pathology in the spine has utilized numerous animal models, with delivery of small molecules, purified factors, and genes of interest. To date, gene delivery to the rat lumbar spine has only been described utilizing genetically programmed cells in a matrix which has required partial disc excision, and expected limitation of treatment diffusion into the disc.
This study was designed to develop and describe a surgical technique for lumbar spine exposure and disc space preparation, and use of a matrix-free method for gene delivery.
Naïve or genetically programmed isogeneic bone marrow stromal cells were surgically delivered to adolescent male Lewis rat lumbar discs, and utilizing quantitative biochemical and qualitative immunohistological assessments, the implanted cells were detected 3 days post-procedure.
Statistically significant differences were noted for recovery of the β-galactosidase marker gene comparing delivery of naïve or labeled cells (105 cells per disc) from the site of implantation, and between delivery of 105 or 106 labeled cells per disc at the site of implantation and the adjacent vertebral body. Immunohistology confirmed that the β-galactosidase marker was detected in the adjacent vertebra bone in the zone of surgical implantation.
The model requires further testing in larger cohorts and with biologically active genes of interest, but the observations from the pilot experiments are very encouraging that this will be a useful comparative model for basic spine research involving gene or cell delivery, or other locally delivered therapies to the intervertebral disc or adjacent vertebral bodies in rats.
PMCID: PMC3640714  PMID: 24426843
gene delivery; lumbar; disc; matrix-free
23.  An objective spinal motion imaging assessment (OSMIA): reliability, accuracy and exposure data 
Minimally-invasive measurement of continuous inter-vertebral motion in clinical settings is difficult to achieve. This paper describes the reliability, validity and radiation exposure levels in a new Objective Spinal Motion Imaging Assessment system (OSMIA) based on low-dose fluoroscopy and image processing.
Fluoroscopic sequences in coronal and sagittal planes were obtained from 2 calibration models using dry lumbar vertebrae, plus the lumbar spines of 30 asymptomatic volunteers. Calibration model 1 (mobile) was screened upright, in 7 inter-vertebral positions. The volunteers and calibration model 2 (fixed) were screened on a motorised table comprising 2 horizontal sections, one of which moved through 80 degrees. Model 2 was screened during motion 5 times and the L2-S1 levels of the volunteers twice. Images were digitised at 5fps.
Inter-vertebral motion from model 1 was compared to its pre-settings to investigate accuracy. For volunteers and model 2, the first digitised image in each sequence was marked with templates. Vertebrae were tracked throughout the motion using automated frame-to-frame registration. For each frame, vertebral angles were subtracted giving inter-vertebral motion graphs. Volunteer data were acquired twice on the same day and analysed by two blinded observers. The root-mean-square (RMS) differences between paired data were used as the measure of reliability.
RMS difference between reference and computed inter-vertebral angles in model 1 was 0.32 degrees for side-bending and 0.52 degrees for flexion-extension. For model 2, X-ray positioning contributed more to the variance of range measurement than did automated registration. For volunteer image sequences, RMS inter-observer variation in intervertebral motion range in the coronal plane was 1.86 degreesand intra-subject biological variation was between 2.75 degrees and 2.91 degrees. RMS inter-observer variation in the sagittal plane was 1.94 degrees. Radiation dosages in each view were below the levels recommended for a plain film.
OSMIA can measure inter-vertebral angular motion patterns in routine clinical settings if modern image intensifier systems are used. It requires skilful radiography to achieve optimal positioning and dose limitation. Reliability in individual subjects can be judged from the variance of their averaged inter-vertebral angles and by observing automated image registration.
PMCID: PMC1351178  PMID: 16393336
24.  Placement of pedicle screws using three-dimensional fluoroscopy-based navigation in lumbar vertebrae with axial rotation 
European Spine Journal  2010;19(11):1928-1935.
Despite potential advantages of three-dimensional fluoroscopy-based navigation, there still remain a lot of controversies about the indications of this technology, especially whether it is worthy of being used in placement of pedicle screws in lumbar spine. However, according to the inconsistent conclusions reported in the literature and our experiences, the traditional method relying on anatomical landmarks and fluoroscopic views to guide lumbar pedicle screw insertion is unable to meet the requirement of precise screw placement. Based on our observation, screw malposition seems to occur concomitant with vertebral axial rotation which is a ubiquitous phenomenon. Three-dimensional fluoroscopy-based navigation can provide the most valuable axial images in real-time, so it may be useful for placement of pedicle screws in lumbar spine. This study was intended to evaluate the effect of axial rotation of lumbar vertebrae on the accuracy of pedicle screw placement using the traditional method, as well as assess the value of three-dimensional fluoroscopy-based navigation in improving the accuracy. Sixteen lumbar simulation models at different degrees of axial rotation (0°, 5°, 10°, and 20°), with every four assigned the same degree, were equally divided into two groups (traditional method group and three-dimensional fluoroscopy-based navigation group). Random placement of pedicle screws was carried out, followed by CT scan postoperatively. Then the outer pedicle cortex contours were depicted from reconstructed sectional pedicle images using Photoshop. The accuracy of pedicle screw placement was evaluated by determining the interrelationship between screw trajectory and pedicle cortex (quality), and measuring the shortest distance from pedicle screw axis to outer cortex of the pedicle (quantity). Eighty pedicle screws were implanted, respectively, in each group. In traditional method group, statistical difference existed in the accuracy of pedicle screw placement at different axial rotational degrees (P < 0.05). With degrees increasing, the accuracy declined. The accuracy of three-dimensional fluoroscopy-based navigation group was higher than traditional method group in vertebrae with axial rotation (P < 0.01). In qualitative evaluation, the accuracy of the two methods had statistical difference when the degree was 20°, and in quantitative evaluation, statistical difference existed in 5°, 10°, and 20° of vertebral axial rotation.
PMCID: PMC2989269  PMID: 20821028
Lumbar spine; Pedicle screw; Vertebral rotation; Three-dimensional fluoroscopy-based navigation; Accuracy
25.  Geometrical dimensions of the lower lumbar vertebrae – analysis of data from digitised CT images 
European Spine Journal  2000;9(3):242-248.
The precise dimensions of the lumbar vertebrae and discs are critical for the production of appropriate spinal implants. Unfortunately, existing databases of vertebral and intervertebral dimensions are limited either in accuracy, study population or parameters recorded. The objective of this study is to provide a large and accurate database of lumbar spinal characteristics from 126 digitised computed tomographic (CT) images, reviewed using the Picture Archiving Communication System (PACS) coupled with its internal measuring instrumentation. These CT images were obtained from patients with low back pain attending the spinal clinic at the Hammersmith Hospitals NHS Trust. Measurements of various aspects of vertebral dimensions and geometry were recorded, including vertebral and intervertebral disc height. The results from this study indicated that the depth and width of the vertebral endplate increased from the third to the fifth lumbar vertebra. Anterior vertebral height remained the same from the third to the fifth vertebra, but the posterior vertebral height decreased. Mean disc height in the lower lumbar segments was 11.6 ± 1.8 mm for the L3/4 disc, 11.3 ± 2.1 mm for the L4/5, and 10.7 ± 2.1 mm for the L5/S1 level. The average circumference of the lower endplate of the fourth lumbar vertebra was 141 mm and the average surface area was 1492 mm2. An increasing pedicle width from a mean of 9.6 ± 2.2 mm at L3 through to 16.2 ± 2.8 mm at L5 was noted. A comprehensive database of vertebral and intervertebral dimensions was generated from 378 lumbar vertebrae from 126 patients measured with a precise digital technique. These results are invaluable in establishing an anthropometric model of the human lumbar spine, and provide useful data for anatomical research. In addition this is important information for the scientific planning of spinal surgery and for the design of spinal implants.
PMCID: PMC3611390  PMID: 10905444
Key words Lumbar vertebrae; Anatomical dimensions; Spine

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