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Diffusion-weighted imaging (DWI) can provide valuable structural information about tissues that may be useful for clinical applications in evaluating lumbar foraminal nerve root entrapment. Our purpose was to visualize the lumbar nerve root and to analyze its morphology, and to measure its apparent diffusion coefficient (ADC) in healthy volunteers and patients with lumbar foraminal stenosis using 1.5-T magnetic resonance imaging. Fourteen patients with lumbar foraminal stenosis and 14 healthy volunteers were studied. Regions of interest were placed at the fourth and fifth lumbar root at dorsal root ganglia and distal spinal nerves (at L4 and L5) and the first sacral root and distal spinal nerve (S1) on DWI to quantify mean ADC values. The anatomic parameters of the spinal nerve roots can also be determined by neurography. In patients, mean ADC values were significantly higher in entrapped roots and distal spinal nerve than in intact ones. Neurography also showed abnormalities such as nerve indentation, swelling and running transversely in their course through the foramen. In all patients, leg pain was ameliorated after selective decompression (n = 9) or nerve block (n = 5). We demonstrated the first use of DWI and neurography of human lumbar nerves to visualize and quantitatively evaluate lumbar nerve entrapment with foraminal stenosis. We believe that DWI is a potential tool for diagnosis of lumbar nerve entrapment.

Study Design: Retrospective case-control study.

Objective: To compare the effectiveness between caudal and trans-foraminal epidural steroid injections for the treatment of primary lumbar radiculopathy.

Summary of Background Data: Spinal injections with steroids play an important role in non-operative care of lumbar radiculopathy. The trans-foraminal epidural steroid injection (TESI) theoretically has a higher success rate based on targeted delivery to the symptomatic nerve root. To our knowledge, these results have not been compared with other techniques of epidural steroid injection.

Methods: 93 patients diagnosed with primary lumbar radiculopathy of L4, L5, or SI were recruited for this study: 39 received caudal epidural steroid injections (ESI) and 54 received trans-foraminal epidural steroid injections (TESI). Outcomes scores included the SF-36, Oswestry disability index (ODI) and pain visual analogue scale (VAS), and were recorded at baseline, post-treatment (<6 months), long-term (>1 year). The average follow-up was 2 years, and 16 patients were lost to follow-up. The endpoint “surgical intervention” was a patient-driven decision, and considered failure of treatment. Intent-to-treat analysis, and comparisons included t-test, Chi-square, and Wilcoxon rank-sum test.

Results: Baseline demographics and outcomes scores were comparable for both treatment groups (ESI vs. TESI): (SF-36 PCS (32.3 ± 7.5 vs. 29.5 ± 8.9 respectively; p = 0.173), MCS (41.2 ± 12.7 vs. 41.1 ± 10.9, respectively; p = 0.971), and VAS (7.4 ±2.1 vs. 7.9 ± 1.2, respectively; p = 0.228)). Surgery was indicated for failure of treatment at a similar rate for both groups (41.0% vs. 44.4%, p=0.743). Symptom improvement was comparable between both treatment groups (ESI vs. TESI): SF-36 PCS improved to 42.0±11.8 and 37.7±12.3, respectively; p=0.49; ODI improved from 50.0±21.2 to 15.6±17.9and from 62.1±17.9 to 26.1±20.3, respectively (p=0.407).

Conclusions: The effectiveness of TESI is comparable to that of ESI (approximately 60%) for the treatment of primary lumbar radiculopathy. The increased complexity of TESI is not justified for primary cases, and may have a more specific role in recurrent disease or for diagnostic purposes.

A foraminal gas pseudocyst is a rare cause of lumbar radiculopathy. The association with a sudden foot drop has not been previously reported. Here, a 67-year-old woman with sudden foot drop on the left side is reported. Computed tomography and magnetic resonance imaging identified a foraminal gas containing lesion compressing the left L5 root at the L5-S1 foramen. The foraminal gas containing lesion compressing the L5 ganglion was successfully removed by the posterior approach. The histological diagnosis was a gas pseudocyst. This unique case of surgically proven gas pseudocyst indicates that it should be included in the differential diagnosis of patients presenting with sudden foot drop.

Background

Chronic low back pain can be a manifestation of lumbar degenerative disease, herniation of intervertebral discs, arthritis, or lumbar stenosis. When nerve roots are compromised, low back pain, with or without lower extremity involvement, may occur. Local inflammatory processes play an important role in patients with acute lumbosciatic pain. The purpose of this study was to assess the value of erythrocyte sedimentation rate (ESR) and high sensitivity C-reactive protein (hsCRP) measurements in patients with chronic low back pain or radiculopathy.

Methods

ESR and hsCRP were measured in 273 blood samples from male and female subjects with low back pain and/or radiculopathy due to herniated lumbar disc, spinal stenosis, facet syndrome, and other diseases. The hsCRP and ESR were measured prior to lumbar epidural steroid injection.

Results

The mean ESR was 18.8 mm/h and mean hsCRP was 1.1 mg/L. ESR had a correlation with age.

Conclusions

A significant systemic inflammatory reaction did not appear to arise in patients with chronic low back pain.

Several techniques have been described for selective nerve root blocks. We describe a novel ‘two-needle technique’, performed through the postero-lateral route with the patient in lateral position under C-arm guidance. The aim of the current study is to highlight the effectiveness and safety of cervical selective nerve root block for radiculopathy using this technique. We present results of a retrospective 2-year follow-up study of 33 injections carried out on 33 patients with radiculopathy due to cervical disc disease and or foraminal stenosis using this procedure. Patients with myelopathy, gross motor weakness and any other pathology were excluded. The outcome was measured comparing ‘Visual Analogue Score’ (VAS) and ‘Neck Disability Index’ (NDI) before the procedure with those at 6 weeks and 12 months after the procedure. Thirty patients were included in the final analysis. Average pre-operative VAS score was 7.4 (range 5–10), which improved to 2.2 (range 0–7) at 6 weeks and 2.0 (range 0–4) at 1 year and the mean NDI score prior to intervention was 66.9 (range 44–84), which improved to 31.7 (range 18–66) at 6 weeks and 31.1 (range 16–48) at 1 year. The improvements were statistically significant. Patients with involvement of C6 or C7 nerve roots responded slightly better at 6 weeks with regards to VAS improvement. Mean duration of radiation exposure during the procedure was 27.8 s (range 10–90 s). Only minor complications were noted—transient dizziness in two and transient nystagmus in one patient. Our ‘two-needle technique’ is a new, safe and effective non-surgical treatment for cervical radiculopathy.

This study was done to present our surgical experience of modified transcorporeal anterior cervical microforaminotomy (MTACM) assisted by the O-arm-based navigation system for the treatment of cervical disc herniation. We present eight patients with foraminal disc herniations at the C5–C6, C6–C7, and C7–T1 levels. All patients had unilateral radicular arm pain and motor weakness. The inclusion criteria for the patients were the presence of single-level unilateral foraminal cervical disc herniation manifesting persistent radiculopathy despite conservative treatment. Hard disc herniation, down-migrated disc herniation, concomitant moderate to severe bony spur and foraminal stenosis were excluded. We performed MTACM to expose the foraminal area of the cervical disc and removed the herniated disc fragments successfully using O-arm-based navigation. Postoperatively, the patients’ symptoms improved and there was no instability during the follow-up period. MTACM assisted by O-arm-based navigation is an effective, safe, and precise minimally invasive procedure that tends to preserve non-degenerated structures as much as possible while providing a complete removal of ruptured disc fragments in the cervical spine.

The ligamentum flavum is considered to be one of the important causes of radiculopathy in lumbar degenerative disease. Although there have been several reports anatomically examining the positional relationship between the ligamentum flavum and nerve root, there are few reports on ventral observation. The purpose of this study is to clarify the shape of the ligamentum flavum seen ventrally, and to obtain anatomic findings related to nerve root compression. The subjects were 18 adult embalmed cadavers, with an average age of 78 years at the time of death. The ventral shapes of the ligamentum flavum were observed. The relationships between the morphological change of the ligamentum flavum and nerve root compression or radiographic findings were statistically evaluated. Among the shapes of the ligamentum flavum, bulging of the ligament was most frequently observed. Proximal bulging indicates the type with the cranial portion bulging from the subarticular zone to the foraminal zone of the ligamentum flavum. In this type associated with a decrease in disc height, nerve root compression was frequently observed. Thus, we could more realistically grasp the relationship between bulging morphology of the ligamentum flavum and nerve root compression.

Objective

To investigate the role of lumbosacral radiculography using 3-dimentional (3D) magnetic resonance (MR) rendering for diagnostic information of symptomatic extraforaminal stenosis in lumbosacral transitional vertebra.

Materials and Methods

The study population consisted of 18 patients with symptomatic (n = 10) and asymptomatic extraforaminal stenosis (n = 8) in lumbosacral transitional vertebra. Each patient underwent 3D coronal fast-field echo sequences with selective water excitation using the principles of the selective excitation technique (Proset imaging). Morphologic changes of the L5 nerve roots at the symptomatic and asymptomatic extraforaminal stenosis were evaluated on 3D MR rendered images of the lumbosacral spine.

Results

Ten cases with symptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. On 3D MR lumbosacral radiculography, indentation of the L5 nerve roots was found in two cases, while swelling of the nerve roots was seen in eight cases at the exiting nerve root. Eight cases with asymptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. Based on 3D MR lumbosacral radiculography, indentation or swelling of the L5 nerve roots was not found in any cases with asymptomatic extraforaminal stenosis.

Conclusion

Results from 3D MR lumbosacral radiculography Indicate the indentation or swelling of the L5 nerve root in symptomatic extraforaminal stenosis. Based on these findings, 3D MR radiculography may be helpful in the diagnosis of the symptomatic extraforaminal stenosis with lumbosacral transitional vertebra.

Objective

Surgical treatment of lumbosacral foraminal stenosis requires an understanding of the anatomy of the lumbosacral area in individual patients. Unilateral facetectomy has been used to completely decompress entrapment of the L5 nerve root, followed in some patients by posterior lumbar interbody fusion (PLIF) with stand-alone cages.

Methods

We assessed 34 patients with lumbosacral foraminal stenosis who were treated with unilateral facetectomy and PLIF using stand-alone cages in our center from January 2004 to September 2007. All the patients underwent follow-up X-rays, including a dynamic view, at 3, 6, 12, 24 months, and computed tomography (CT) at 24 months postoperatively. Clinical outcomes were analyzed with the mean numeric rating scale (NRS), Oswestry Disability Index (ODI) and Odom's criteria. Radiological outcomes were assessed with change of disc height, defined as the average of anterior, middle, and posterior height in plain X-rays. In addition, lumbosacral fusion was also assessed with dynamic X-ray and CT.

Results

Mean NRS score, which was 9.29 prior to surgery, was 1.5 at 18 months after surgery. The decrease in NRS was statistically significant. Excellent and good groups with regard to Odom's criteria were 31 cases (91%) and three cases (9%) were fair. Pre-operative mean ODI of 28.4 decreased to 14.2 at post-operative 24 months. In 30 patients, a bone bridge on CT scan was identified. The change in disc height was 8.11 mm, 10.02 mm and 9.63 mm preoperatively, immediate postoperatively and at 24 months after surgery, respectively.

Conclusion

In the treatment of lumbosacral foraminal stenosis, unilateral facetectomy and interbody fusion using expandable stand-alone cages may be considered as one treatment option to maintain post-operative alignment and to obtain satisfactory clinical outcomes.

Lumbar epidural anesthesia is useful in a variety of chronic benign pain syndromes, including lumbar radiculopathy, low back pain syndrome, spinal stenosis, and vertebral compression fractures. Given the increased number of epidural nerve blocks being performed, some have reported unexplained complications of a transient or permanent nature and with varying degrees of severity. However, no case has been reported of a broken epidural needle tip retained in the lumbar facet joint area. This represents the first reported case presentation of foraminal stenosis developing in a patient after a retained epidural needle tip.

Study Design

This is a prospective study.

Purpose

We compared the outcomes of segmental decompression and wide decompression in patients who had multilevel lumbar foraminal stenosis with back pain.

Overview of Literature

Wide decompression and fusion in patients with multilevel lumbar foraminal stenosis may increase the risk of perioperative complications.

Methods

From March 2005 to December 2007, this study prospectively examined 87 patients with multilevel lumbar foraminal stenosis and who were treated by segmental or wide decompression along with posterior fusion using pedicle screw fixation, and these patients could be followed-up for a minimum of 2 years. Of the 87 patients, 45 and 42 patients were assigned to the segmental decompression group (group 1) and the wide decompression group (group 2), respectively. We compared the clinical and radiological outcomes of the patients in these two groups.

Results

There were no significant differences between groups 1 and 2 in terms of the levels of postoperative pain based on the visual analogue scale, the Oswestry Disability Score, the clinical results based on the Kirkaldy-Willis Criteria, the complication rate or the posterior fusion rate. On the other hand, the mean operating times in groups 1 and 2 were 153 ± 32 minutes and 187 ± 36 minutes, respectively (p < 0.05). The amount of blood loss during surgery and on the first postoperative day was 840 ± 236 ml and 1,040 ± 301 ml in groups 1 and 2, respectively (p < 0.05).

Conclusions

These results suggest that segmental decompression offers promising and reproducible clinical and radiological results for patients suffering from multilevel lumbar foraminal stenosis.

Introduction

Cervical disc herniation often results in neck and arm pain in patients as a result of direct impingement of nerve roots and associated inflammatory processes. The clinical presentation usually corresponds with the side of herniation and ipsilateral symptoms predominate the clinical picture.

Case presentation

A 35-year-old Caucasian man presented to our facility with neck pain and left-sided upper and lower extremity pain. A magnetic resonance imaging scan revealed a right paramedian herniated disc at the C5 to C6 level. All other cervical levels were normal without central canal stenosis or neural foraminal stenosis. Results from magnetic reasonance imaging scans of the brain and lumbar spine were negative. An anterior cervical discectomy was performed at the C5 to C6 level, and an inter-body graft and plate were placed. Our patient had complete resolution of his neck and left arm pain.

Conclusions

Anterior discectomy and fusion of the cervical spine resulted in complete resolution of our patient’s neck and left arm symptoms and improvement of his contralateral left leg pain. Cervical disc herniation may present with contralateral symptoms that are different from the current perception of this disease.

Lumbar spinal stenosis, the results of congenital and degenerative constriction of the neural canal and foramina leading to lumbosacral nerve root or cauda equina compression, is a common cause of disability in middle-aged and elderly patients. Advanced neuroradiologic imaging techniques have improved our ability to localize the site of nerve root entrapment in patients presenting with neurogenic claudication or painful radiculopathy. Although conservative medical management may be successful initially, surgical decompression by wide laminectomy or an intralaminar approach should be done in patients with serious or progressive pain or neurologic dysfunction. Because the early diagnosis and treatment of lumbar spinal stenosis may prevent intractable pain and the permanent neurologic sequelae of chronic nerve root entrapment, all physicians should be aware of the different neurologic presentations and the treatment options for patients with spinal stenosis.

Images

Purpose

The purpose of this study is to report clinical outcome and imaging changes of percutaneous Aperius stand-alone implant in patients with degenerative lumbar spinal stenosis and neurogenic intermittent claudication, which did not respond to conservative treatment.

Method

Between January 2008 and July 2010, 37 patients (20 males and 17 females) with mean age of 64.3 years underwent surgery for the onset of claudicatio spinalis with Aperius PercLID interspinous device (Medtronic). In all patients, the diagnosis was: foraminal stenosis, in one case (2.7 %) it was associated to a degenerative anterior listhesis (I grade), in three cases (8.1 %) it was associated to an intraforaminal disc herniation. The mean follow-up was of 18 months (range 2–35 months). The patients were evaluated through the Oswestry disability index, Zurich Claudication Questionnaire (ZCQ), VAS scales. In all cases were obtained preoperative and in postoperative radiographs and magnetic resonance imaging.

Results

The VAS score decreased significantly after surgery: the patients presented a mean VAS of seven preoperatively and two postoperatively (p < 0.001).

The ZCQ score significantly decreased postoperatively, with an average reduction of 21.89 % (p < 0.001).

The ODI score as well showed a significant reduction postoperatively of an average 26.09 % (p < 0.001).

Conclusion

Despite of the brief follow up, the preliminary results are encouraging, showing a significantly decrease of the disability parameters, a marked improvement of the function with the vanishing of the claudicatio spinalis and the following increase of the free interval during the walk. Aperius PercLID system seems to offer an alternative to the traditional decompression surgery.

Study Design

A reliability assessment of standardized magnetic resonance imaging (MRI) interpretations and measurements.

Objective

To determine the intra- and inter-reader reliability of MRI features of lumbar spinal stenosis (SPS), including severity of central, subarticular, and foraminal stenoses, grading of nerve root impingement, and measurements of cross-sectional area of the spinal canal and thecal sac.

Summary of Background Data

MRI is commonly used to assess patients with spinal stenosis. Although a number of studies have evaluated the reliability of certain MRI characteristics, comprehensive evaluation of the reliability of MRI readings in spinal stenosis is lacking.

Methods

Fifty-eight randomly selected MR images from patients with SPS enrolled in the Spine Patient Outcomes Research Trial were evaluated. Qualitative ratings of imaging features were performed according to defined criteria by 4 independent readers (3 radiologists and 1 orthopedic surgeon). A sample of 20 MRIs was reevaluated by each reader at least 1 month later. Weighted κ statistics were used to characterize intra- and inter-reader reliability for qualitative rating data. Separate quantitative measurements were performed by 2 other radiologists. Intraclass correlation coefficients and summaries of measurement error were used to characterize reliability for quantitative measurements.

Results

Intra-reader reliability was higher than interreader reliability for all features. Inter-reader reliability in assessing central stenosis was substantial, with an overall κ of 0.73 (95% CI 0.69-0.77). Foraminal stenosis and nerve root impingement showed moderate to substantial agreement with overall κ of 0.58 (95% CI 0.53-0.63) and 0.51 (95% CI 0.42-0.59), respectively. Subarticular zone stenosis yielded the poorest agreement (overall κ 0.49; 95% CI 0.42-0.55) and showed marked variability in agreement between reader pairs. Quantitative measures showed inter-reader intraclass correlation coefficients ranging from 0.58 to 0.90. The mean absolute difference between readers in measured thecal sac area was 128 mm2 (13%).

Conclusion

The imaging characteristics of spinal stenosis assessed in this study showed moderate to substantial reliability; future studies should assess whether these findings have prognostic significance in SPS patients.

Background and Objectives

Previous studies have concluded that transforaminal epidural steroid injections (ESIs) are more effective than interlaminar injections in the treatment of radiculopathies due to lumbar intervertebral disk herniation. There are no published studies examining the depth of epidural space using a transforaminal approach. We investigated the relationship between body mass index (BMI) and the depth of the epidural space during lumbar transforaminal ESIs.

Methods

Eighty-six consecutive patients undergoing lumbar transforaminal ESI at the L3-L4, L4-L5, and L5-S1 levels were studied. Using standard protocol, the foraminal epidural space was attained using fluoroscopic guidance. The measured distance from needle tip to skin was recorded (depth to foraminal epidural space). The differences in the needle depth and BMI were analyzed using regression analysis.

Results

Needle depth was positively associated with BMI (regression coefficient [RC], 1.13; P < 0.001). The median depths (in centimeters) to the epidural space were 6.3, 7.5, 8.4, 10.0, 10.4, and 12.2 for underweight, normal, preobese, obese I, obese II, and obese III classifications, respectively. Sex (RC, 1.3; P = 0.02) and race (RC, 0.8; P = 0.04) were also significantly associated with needle depth; however, neither factor remained significant when BMI was accounted as a covariate in the regression model. Age, intervertebral level treated, and oblique angle had no predictive value on foraminal depth (P > 0.2).

Conclusion

There is a positive association between BMI and transforaminal epidural depth, but not with age, sex, race, oblique angle, or intervertebral level.

Existing studies on micro-endoscopic lumbar discectomy report similar outcomes to those of open and microdiscectomy and conflicting results on complications. We designed a randomised controlled trial to investigate the hypothesis of different outcomes and complications obtainable with the three techniques. 240 patients aged 18–65 years affected by posterior lumbar disc herniation and symptoms lasting over 6 weeks of conservative management were randomised to micro-endoscopic (group 1), micro (group 2) or open (group 3) discectomy. Exclusion criteria were less than 6 weeks of pain duration, cauda equina compromise, foraminal or extra-foraminal herniations, spinal stenosis, malignancy, previous spinal surgery, spinal deformity, concurrent infection and rheumatic disease. Surgery and follow-up were made at a single Institution. A biomedical researcher independently collected and reviewed the data. ODI, back and leg VAS and SF-36 were the outcome measures used preoperatively, postoperatively and at 6-, 12- and 24-month follow-up. 212/240 (91%) patients completed the 24-month follow-up period. VAS back and leg, ODI and SF36 scores showed clinically and statistically significant improvements within groups without significant difference among groups throughout follow-up. Dural tears, root injuries and recurrent herniations were significantly more common in group 1. Wound infections were similar in group 2 and 3, but did not affect patients in group 1. Overall costs were significantly higher in group 1 and lower in group 3. In conclusion, outcome measures are equivalent 2 years following lumbar discectomy with micro-endoscopy, microscopy or open technique, but severe complications are more likely and costs higher with micro-endoscopy.

A 55-year-old obese man (body mass index, 31.6 kg/m2) presented radiating pain and motor weakness in the left leg. Magnetic resonance imaging showed an epidural mass posterior to the L5 vertebral body, which was isosignal to subcutaneous fat and it asymmetrically compressed the left side of the cauda equina and the exiting left L5 nerve root on the axial T1 weighted images. Severe arthritis of the left facet joint and edema of the bone marrow regarding the left pedicle were also found. As far as we know, there have been no reports concerning a solitary epidural lipoma combined with ipsilateral facet arthorsis causing lumbar radiculopathy. Solitary epidural lipoma with ipsilateral facet arthritis causing lumbar radiculopathy was removed after the failure of conservative treatment. After decompression, the neurologic deficit was relieved. At a 2 year follow-up, motor weakness had completely recovered and the patient was satisfied with the result. We recommend that a solitary epidural lipoma causing neurologic deficit should be excised at the time of diagnosis.

Transforaminal lumbar interbody fusion (TLIF) is an effective treatment for patients with degenerative spondylolisthesis and degenerative disc disease. Opposite side radiculopathy after the TLIF procedure has been recognized in this institution but has not been addressed in the literature. We present a case of opposite side radiculopathy after the TLIF procedure. We believe that this complication is related to asymptomatic stenosis on the contralateral side that is unmasked by the increased lordosis of the TLIF. The authors recommend increasing both disc height and foraminal height when choosing an interbody graft, and possibly decompressing the opposite foramen when preoperative MRI demonstrates foraminal stenosis.

Sciatica is commonly caused by lumbar prolapsed intervertebral disc (PID) and other spinal lesions. Uncommon causes like nerve root schwannoma are rarely considered in the differential diagnosis of sciatica. Spinal schwannomas occur both sporadically and in association with neurofibromatosis type 1 (NF1; von Recklinghausen's disease). This case report describes lumbar foraminal schwannoma as an unusual cause of radiculopathy, presenting clinically as a lumbar disc prolapse. The diagnosis was confirmed on MRI scan. Patient had complete symptomatic recovery following surgical enucleation of the tumour mass from the L5 nerve root. This case report is of particular interest as it highlights the diagnostic confusion, which is bound to arise, because the clinical presentation closely mimics a lumbar PID. This often leads to delay in diagnosis and “failure of conservative treatment.”

Background: Foraminal stenosis is an important cause of radicular and generalized back pain. In patients who do not respond to conservative interventions, endoscopic spinal surgery provides similar results to open surgical approaches with lower rates of complication, postoperative pain, and shorter duration of hospital stay.

Methods: We performed a prospective, open, uncontrolled trial of 64 patients to evaluate endoscopic laminoforaminoplasty for the treatment of refractory foraminal stenosis.

Results: Fifty-nine percent of patients had at least 75% improvement in Oswestry Disability Index (Oswestry) and Visual Analog Scale (VAS) scores. All patients were discharged the day of surgery. Dural leaks occurred in two patients, which were repaired intraoperatively. No other adverse events occurred.

Conclusions: Endoscopic laminoforaminoplasty appears to be a safe alternative to open decompression in patients with spinal foraminal stenosis; additional controlled trials are warranted.

Interspinous implants are used to treat lumbar spinal stenosis or facet joint arthritis. The aims of implanting interspinous devices are to unload the facet joints, restore foraminal height and provide stability especially in extension but still allow motion. The aim of this in vitro study was to compare four different interspinous implants––Colfex, Wallis, Diam and X-Stop––in terms of their three-dimensional flexibility and the intradiscal pressure. Twenty-four human lumbar spine specimens were divided into four equal groups and tested with pure moments in flexion/extension, lateral bending and axial rotation: (1) intact, (2) defect, (3) after implantation. Range of motion and the intradiscal pressure were determined.In each implant-group the defect caused an increase in range of motion by about 8% in lateral bending to 18% in axial rotation. Implantation had similar effects with all four implants. In extension, Coflex, Wallis, Diam, and X-Stop all overcompensated the instability caused by the defect and allowed about 50% of the range of motion of the intact state. In contrast, in flexion, lateral bending and axial rotation the values of the range of motion stayed about the values of the defect state. Similarly the intradiscal pressure after implantation was similar to that of the intact specimens in flexion, lateral bending and axial rotation but much smaller during extension. All tested interspinous implants had a similar effect on the flexibility: they strongly stabilized and reduced the intradiscal pressure in extension, but had almost no effect in flexion, lateral bending and axial rotation.

Large lumbosacral disc herniations effacing both the paramedian and the foraminal area often cause double radicular compression. Surgical management of these lesions may be difficult. A traditional interlaminar approach usually brings into view only the paramedian portion of the intervertebral disc, unless the lateral bone removal is considerably increased. Conversely, the numerous far-lateral approaches proposed for removing foraminal or extraforaminal disc herniations would decompress the exiting nerve root only. Overall, these approaches share the drawback of controlling the neuroforamen on one side alone. A combined intra-extraforaminal exposure is a useful yet rarely reported approach. Over a 3-year period, 15 patients with bi-radicular symptoms due to large disc herniations of the lumbar spine underwent surgery through a combined intra-extracanal approach. A standard medial exposure with an almost complete hemilaminectomy of the upper vertebra was combined with an extraforaminal exposure, achieved by minimal drilling of the inferior facet joint, the lateral border of the pars interarticularis and the inferior margin of the superior transverse process. The herniated discs were removed using key maneuvers made feasible by working simultaneously on both operative windows. In all cases the disc herniation could be completely removed, thus decompressing both nerve roots. Radicular pain was fully relieved without procedure-related morbidity. The intra-extraforaminal exposure was particularly useful in identifying the extraforaminal nerve root early. Early identification was especially advantageous when periradicular scar tissue hid the nerve root from view, as it did in patients who had undergone previous surgery at the same site or had long-standing radicular symptoms. Controlling the foramen on both sides also reduced the risk of leaving residual disc fragments. A curved probe was used to push the disc material outside the foramen. In conclusion, specific surgical maneuvers made feasible by a simultaneous extraspinal and intraspinal exposure allow quick, safe and complete removal of lumbosacral disc herniations with paramedian and foraminal extension.

Objective

This retrospective study was performed to evaluate the clinical and radiological results of anterior lumbar interbody fusion (ALIF) using two different stand-alone cages in the treatment of lumbar intervertebral foraminal stenosis (IFS).

Methods

A total of 28 patients who underwent ALIF at L5-S1 using stand-alone cage were studied [Stabilis® (Stryker, Kalamazoo, MI, USA); 13, SynFix-LR® (Synthes Bettlach, Switzerland); 15]. Mean follow-up period was 27.3 ± 4.9 months. Visual analogue pain scale (VAS) and Oswestry disability index (ODI) were assessed. Radiologically, the change of disc height, intervertebral foraminal (IVF) height and width at the operated segment were measured, and fusion status was defined.

Results

Final mean VAS (back and leg) and ODI scores were significantly decreased from preoperative values (5.6 ± 2.3 → 2.3 ± 2.2, 6.3 ± 3.2 → 1.6 ± 1.6, and 53.7 ± 18.6 → 28.3 ± 13.1, respectively), which were not different between the two devices groups. In Stabilis® group, postoperative immediately increased disc and IVF heights (10.09 ± 4.15 mm → 14.99 ± 1.73 mm, 13.00 ± 2.44 mm → 16.28 ± 2.23 mm, respectively) were gradually decreased, and finally returned to preoperative value (11.29 ± 1.67 mm, 13.59 ± 2.01 mm, respectively). In SynFix-LR® group, immediately increased disc and IVF heights (9.60 ± 2.82 mm → 15.61 ± 0.62 mm, 14.01 ± 2.53 mm → 21.27 ± 1.93 mm, respectively) were maintained until the last follow up (13.72 ± 1.21 mm, 17.87 ± 2.02 mm, respectively). The changes of IVF width of each group was minimal pre- and postoperatively. Solid arthrodesis was observed in 11 patients in Stabilis group (11/13, 84.6%) and 13 in SynFix-LR® group (13/15, 86.7%).

Conclusion

ALIF using stand-alone cage could assure good clinical results in the treatment of symptomatic lumbar IFS in the mid-term follow up. A degree of subsidence at the operated segment was different depending on the device type, which was higher in Stabilis® group.

Study Design

A retrospective study.

Purpose

An en bloc partial laminectomy and posterior lumbar interbody fusion (PLIF) in spinal stenosis patients with severe foraminal narrowing has a shorter operation time, less neural manipulation and allows indirect decompression by restoring the interforaminal height compared to other procedures. This study investigated the efficacy of the procedure.

Overview of Literature

PLIF is one of the most popular surgery for degenerative spine such as foraminal spinal stenosis, instability spondylolisthesis and discogenic pain. Various techniques for PLIF have their own advantages and disadvantages. But in some severe cases, we need an efficient method of PLIF for decompression and fusion.

Methods

This study examined 61 patients, who had 85 levels treated with PLIF using an en bloc partial laminectomy and facetectomy, and could be followed up for more than 2 years. The mean age of the patients and mean follow up period was 66 years and 39 months, respectively. The clinical results were evaluated using the MacNab's criteria, Visual Analogue Scale (VAS) score, and Korea Version Oswestry Disability Index (KODI). The union of the intervertebral space was evaluated using Lenke's criteria. The intervertebral angle and height of the posterior intervertebral disc were also measured.

Results

Excellent and good results were obtained in 54 cases (89%) according to MacNab's criteria. The VAS and KODI scores were 8.1 and 34.6, preoperatively, and 3.4, and 14.1, postoperatively. Bone union was A and B grades according to Lenke's criteria in 57 cases. The mean segmental angle and mean height of the posterior disc were respectively, 7.4° and 6.5 mm preoperatively, 9.1° and 10.6 mm postoperatively, and 8.0° and 9.7 mm in the last follow-up. There were 5 cases of postoperative infection, 4 cases of junctional problems and 1 case of screw malposition.

Conclusions

En bloc partial laminectomy and PLIF is an effective method for treating severe spinal stenosis with foraminal narrowing.