Topography of the uncinate fascicle and adjacent temporal fiber tracts

Summary A prospective intra-operative analysis of the location of lumbar disc herniation was performed in 131 patients with verified 54% contained (incomplete) and 46% non-contained (complete) lumbar disc herniations. Bulging discs or protrusions are not included in this study.Complete disc herniations occurred more frequently in the upper lumbar spine. The localization of the lumbar disc herniations within its segment showed no correlation to the affected level. 64% of the disc herniations were located medio-laterally, 20% laterally, 12% within or lateral of the intervertebral compartment and 5% in the midline. Nearly one third of all herniations were found at the level of the disc space. Medio-lateral disc herniations were displaced more often in a caudal direction, lateral herniations were found displaced upwards and downwards with similar frequency while extraforaminal herniations migrated significantly more often in a cranial direction.The pathomechanism and anatomical pathways of disc fragment migration are discussed on the basis of a new concept of the anterior extradural space.Dedicated to Prof. Peter Huber, our respected neuroradiologist and friend.     

Transdural approach for calcified central disc herniations of the upper lumbar spine. Technical note

Disc herniations of the upper lumbar spine (L1-2 and L2-3) have a frequency of 1 to 2% of all disc herniations. During posterior discectomy after laminectomy, significant manipulation of the exiting nerve root is unavoidable because of the narrow lamina and the difficulty in mobilizing the nerve root. The authors adopted a transdural approach in patients with calcified central disc herniation at the L1-2 level to reduce the risk of nerve root injury. Four patients suffering from radiating pain together with back pain were treated using the transdural approach. Preoperative neuroimaging studies revealed severe central disc herniation with calcification at the L1-2 level. After laminectomy or laminotomy, the incised dura mater was tacked, and the cauda equina rootlets were gently retracted. An intentional durotomy was performed over its maximal bulging of the ventral dura. After meticulous dissection of dense adhesions between the disc herniation and the dural sac, adequate decompression with removal of calcified disc fragments and osteophytes was accomplished. Clinical symptoms improved in all patients. Postoperative permanent cerebrospinal fluid leakage and pseudomeningocele were not observed, and no patient had a progressive lumbar deformity at an average follow-up of 53 months. Transient mild motor weakness and sensory change were observed in two patients postoperatively; however, these symptoms resolved completely within 1 week. The posterior transdural approach offers an alternative in central calcified upper lumbar disc herniation when root retraction is dangerous.     

Transforaminal percutaneous endoscopic lumbar discectomy for upper lumbar disc herniation: clinical outcome, prognostic factors, and technical consideration

Background

Compared with lower lumbar disc herniations, upper lumbar disc herniations at L1–L2 and L2–L3 have specific characteristics that result in different surgical outcomes after conventional open discectomy. There are no published studies on the feasibility of percutaneous endoscopic lumbar discectomy for upper lumbar disc herniation. The purpose of this study was to assess the clinical outcome, prognostic factors and the technical pitfalls of PELD for upper lumbar disc herniation.

Method

Forty-five patients with a soft disc herniation at L1–L2 or L2–L3 underwent percutaneous endoscopic discectomy. Posterolateral transforaminal endoscopic laser-assisted disc removal was performed under local anesthesia. Clinical outcomes was assessed using the Prolo scale. The prognostic factors associated with outcome were then analyzed.

Findings

The mean follow-up was 38.8 months (range, 25–52 months). The outcome of the 45 patients was excellent in 21 (46.7%), good in 14 patients (31.1%), fair in six patients (13.3%), and poor in four patients (8.9%). Four patients with a poor outcome underwent further open surgery. Mean scores on a visual analog scale decreased from 8.38 to 2.36 (P?<?0.0001). Age less than 45 years and a lateral disc herniation were independently associated with an excellent outcome (P?<?0.05).

Conclusions

Patient selection and an anatomically modified surgical technique promote a more successful outcome after percutaneous endoscopic discectomy for upper lumbar disc herniation.     

极外侧型腰椎间盘突出症15例报告

目的 探讨极外侧型腰椎间盘突出症的临床和CT特征,提高该病的诊断率。方法 对15例经手术证实的患者临床和CT影像进行回顾性分析。结果 腰4／5间隙多发,椎间孔和椎间孔外联合突出多见,临床上常可见单侧两节神经根受损的表现。结论 临床与CT相结合是诊断极外侧型腰椎间盘突出症的关键。     

Higher preoperative Oswestry Disability Index is associated with better surgical outcome in upper lumbar disc herniations

To evaluate the surgical outcome in terms of functional and subjective recovery, patients who needed discectomies at L1–L2, L2–L3 and L3–L4 levels were compared with an age and sex-matched group of patients who required L4–L5 and L5–S1 discectomies. We prospectively enrolled 50 consecutive patients, referred to our center, who had L1–L2, L2–L3 and L3–L4 herniations and required surgical intervention. Likewise, a comparative group of 50 consecutive patients with herniations at L4–L5 and L5–S1 were selected. All 100 patients were treated and followed for a 1 year period. Physical examination findings as well as Oswestry Disability Questionnaire before surgery were recorded. After 1 year, patients were requested to fill the same questionnaire. Significant decline in the Oswestry Disability Index (ODI) scores was considered to be a measure of functional improvement and recovery. The mean age of patients with upper lumbar disc herniation (L1–L2, L2–L3, L3–L4) was 45.7 years and patients with lower lumbar disc herniation (L4–L5, L5–S1) had a mean age of 41.2 years. There was no statistically significant difference in age between the two groups. The preoperative Oswestry Disability (ODI) Index score had a statistically significant impact on ODI score improvement after surgery in both lower and upper lumbar disc groups. All 100 patients with either lower or upper lumbar disc herniation had statistically significant ODI change after surgical intervention (P < 0.0001 for both groups). However, patients with upper disc herniations and moderate preoperative disability (ODI of 21–40%) did not show significant improvement, while patients with ODI greater than 40% had significant reduction (P = 0.018). Surprisingly, as many as 25% of the former had even an increase in ODI scores after surgery. Gender was also a conspicuous factor in determining the surgical outcome of patients with upper lumbar disc herniation, and male patients had more reduction in ODI score than female patients (P = 0.007). Since the functional recovery in patients with herniated lumbar disc, especially upper lumbar herniation, is influenced by preoperative ODI scores, the use of ODI or any other standard pain assessment tool is a sensible consideration as an inherent investigative method to preclude unfavorable surgical outcome.     

The relation between vertebral endplate shape and lumbar disc herniations.

STUDY DESIGN: Blinded review of selected and un-selected computed tomographic myelograms. OBJECTIVE: To determine whether shape of the vertebral body endplate margins is a risk factor for the development of symptomatic lumbar disc herniations. The law of LaPlace for a fluid-filled tube suggests that anular tension could be related to endplate shape and a propensity for disc herniation. SUMMARY OF BACKGROUND DATA: It was hypothesized that the law of Laplace could apply to the lumbar spine because of to the cylindrical shape of the lumbar disc and its high water content in nonelderly individuals. It was further hypothesized that differences in the radius of the curvature could place stresses on the anulus that would make posterior disc herniations more likely with "rounder" endplates. METHODS: Ninety-seven contrast computed tomography scans were reviewed at transitional L4-L5 and L5-S1 in patients under 60 years of age, without previous spine surgery and without spondylolisthesis. Determinations of disc herniations and measurements of endplates were performed by blinded observers. A ratio of these measurements was used to determine the relative circularity of the endplate. Height, weight, body mass index, and disc endplate size and shape were related to the presence of disc herniation. RESULTS: By multiple logistic regression, only endplate shape was strongly related to disc herniations. Endplate area was a less significant factor in men. CONCLUSIONS: The shape of the vertebral body margin at the endplate is an important factor contributing to the development of disc herniations at L4-L5 and L5-S1.     

Anterior lumbar microdiscectomy and interbody fusion for the treatment of recurrent disc herniation

OBJECTIVE: To demonstrate the feasibility of anterior lumbar microdiscectomy in patients with recurrent, sequestered lumbar disc herniations. METHODS: Between 1997 and 1999, six patients underwent a muscle-sparing "minilaparotomy" approach and subsequent microscopic anterior lumbar microdiscectomy and fragmentectomy for recurrent lumbar disc extrusions at L5-S1 (n = 4) or L4-L5 (n = 2). A contralateral distraction plug permitted ipsilateral discectomy under microscopic magnification. Effective resection of the extruded disc fragments was accomplished by opening the posterior longitudinal ligament. Interbody fusion was performed by placing cylindrical threaded titanium cages (n = 4) or threaded allograft bone dowels (n = 2). RESULTS: There were no complications, and blood loss was minimal. Follow-up magnetic resonance imaging revealed complete resection of all herniated disc material. Plain x-rays revealed excellent interbody cage position. Radicular pain and neurological deficits resolved in all six patients (mean follow-up, 14 mo). CONCLUSION: Anterior lumbar microdiscectomy with interbody fusion provides a viable alternative for the treatment of recurrent lumbar disc herniations. Recurrent herniated disc fragments can be removed completely under direct microscopic visualization, and interbody fusion can be performed in the same setting.     

Intradural lumbar disc herniation—Is it predictable preoperatively? A report of two cases

BACKGROUND CONTEXT: Intradural disc herniations are thought to be rare events, and there have been relatively few literature reports of intradural disc herniations available with regard to magnetic resonance imaging findings. PURPOSE: The authors describe two patients with intradural lumbar disc herniations, one with and one without preoperative diagnosis, who had different postoperative outcomes. STUDY DESIGN: Case study METHODS: The first patient underwent an extended L3 subtotal laminectomy followed by bilateral medial facetectomy and foraminotomy at L3-L4. A durotomy uncovered large disc fragments comprised of friable disc materials and end plates, after no clear disc herniation was found in the epidural space. The second patient underwent anterior lumbar interbody fusion after a preoperative diagnosis of intradural disc herniation. RESULTS: The first patient experienced a marked reduction of pain and progressive recovery of sensory disturbance, but neurologic examination showed right foot drop postoperatively. Two years after surgery, she can not walk without a cane because the neurologic deficit of the right ankle has shown no improvement. Two days after surgery, the second patient was allowed to ambulate with a lumbar orthosis. Neurologic examination showed no motor deficit. Twenty-one months after surgery, the patient reports minimal back pain when sitting on a chair for prolonged periods of time. CONCLUSION: Our cases highlight the importance of preoperative diagnosis in the treatment of intradural lumbar disc herniations. The potential presence of an intradural disc herniation must always be considered preoperatively on a patient whose magnetic resonance imaging study demonstrates the "hawk-beak sign" on axial imaging as well as abrupt loss of continuity of the posterior longitudinal ligament (PLL). This association results in an adequate surgical approach, thereby reducing the chance of postoperative neurologic deficit. Finally, anterior lumbar interbody fusion can be a reasonable alternative in the treatment of intradural lumbar disc herniations.     

A minimally invasive transmuscular approach to far-lateral L5-S1 level disc herniations: a prospective study

BACKGROUND: Among all lumbar disc herniations, L5-S1 far-lateral disc herniations are rare entities. Besides, surgical approach may be difficult because of the very narrow passage at this level. For these 2 reasons, most spine surgeons are not experienced in herniations at this level. According to new microanatomic studies, previous lateral approaches at this level often do not allow access to the neuroforamen without partial or total destruction of the L5-S1 facet joint. To preserve the facet joint, an approach was developed. PURPOSE: To assess the efficacy of a surgical technique that is a minimally invasive intermuscular approach (MIIMA) for decompression of L5-S1 far-lateral level disc herniation (FLLDH). STUDY DESIGN: We present a prospective clinical study analysis of 14 patients with L5-S1 far-lateral disc herniations in a period between 2000 and 2004, treated with microsurgical technique. METHODS: An imaging study revealed consistency with the patient's clinical presentation. In our department, a total of 580 patients underwent discectomy between 2000 and 2004 for lumbar disc herniation. RESULT: Twenty-eight patients had foraminal or extraforaminal herniations (4.8%). Fourteen patients had FLLDH at the L4-L5 level (2.4%), whereas the other 14 were cases of FLLDH at the L5-S1 level (2.4%). One patient had FLLDH at both L5-S1 and L4-L5 levels (7.1%). The mean age of patients was 53.6 years, and the male:female ratio was approximately 5:9. All patients failed to recover after at least 6 weeks of conservative therapy. The mean duration of symptoms until the time of surgery was 7.2 months. Using this MIIMA technique, the authors removed the herniated discs compressing the (L5) nerve roots. Clinical outcome was measured using the visual analog scale. Every patient was discharged within 24 hours. Satisfactory (excellent or good) results were demonstrated in 13 patients (92.9%), because, except for 1 (7.1) permanent dysesthesia case, 4 cases (21.3%) were temporary dysesthesia. Postoperatively all patients reported excellent relief of their sciatic pains, and there were no technique-associated complications. No recurrence was observed during the follow-up period ranging from 10 to 60 months (mean, 29 mo). This is one of the major complications of any approach to a far-lateral disc. CONCLUSIONS: The authors describe a MIIMA for excising herniated discs that is applicable to all types of far-lateral lumbar herniations. Postoperative dysesthesia is the most important complication and may persist as it did in our cases. Consequently, manipulation of the ganglion should be avoided at all costs, if possible. The MIIMA procedure provides a simple alternative for treating lumbar foraminal or lateral exit zone herniated discs in selected cases. This approach is effective, allowing the preservation of the L5-S1 facet joint, saving the facet joint, preventing postoperative instability, and offering a direct view of the L5-S1 neuroforamen.     

Biomechanical changes in the lumbar spine following spaceflight and factors associated with postspaceflight disc herniation

Background ContextFor chronic low back pain, the causal mechanisms between pathological features from imaging and patient symptoms are unclear. For instance, disc herniations can often be present without symptoms. There remains a need for improved knowledge of the pathophysiological mechanisms that explore spinal tissue damage and clinical manifestations of pain and disability. Spaceflight and astronaut health provides a rare opportunity to study potential low back pain mechanisms longitudinally. Spaceflight disrupts diurnal loading on the spine and several lines of evidence indicate that astronauts are at a heightened risk for low back pain and disc herniation following spaceflight.PurposeTo examine the relationship between prolonged exposure to microgravity and the elevated incidence of postflight disc herniation, we conducted a longitudinal study to track the spinal health of twelve NASA astronauts before and after approximately 6 months in space. We hypothesize that the incidence of postflight disc herniation and low back complaints associates with spaceflight-included muscle atrophy and pre-existing spinal pathology.Study DesignThis is a prospective longitudinal study.Patient SampleOur sample included a cohort of twelve astronaut crewmembers.Outcome MeasuresFrom 3T MRI, we quantified disc water content (ms), disc degeneration (Pfirrmann grade), vertebral endplate irregularities, facet arthropathy and/ fluid, high intensity zones, disc herniation, multifidus total cross-sectional area (cm²), multifidus lean muscle cross-sectional area (cm²), and muscle quality/composition (%). From quantitative fluoroscopy we quantified, maximum flexion-extension ROM (°), maximum lateral bending ROM (°), and maximum translation (%). Lastly, patient outcomes and clinical notes were used for identifying postflight symptoms associated with disc herniations from 3T MRI.MethodsAdvanced imaging data from 3T MRI were collected at three separate time points in relation to spending six months in space: (1) within a year before launch (“pre-flight”), (2) within a week after return to Earth (“post-flight”), and (3) between 1 and 2 months after return to Earth (“recovery”). Fluoroscopy of segmental kinematics was collected at preflight and postflight timepoints. We assessed the effect of spaceflight and postflight recovery on longitudinal changes in spinal structure and function, as well as differences between crew members who did and did not present a symptomatic disc herniation following spaceflight.ResultsHalf of our astronauts (n=6) experienced new symptoms associated with a new or previously asymptomatic lumbar disc protrusion or extrusion following spaceflight. We observed decreased multifidus muscle quality following spaceflight in the lower lumbar spine, with a reduced percentage of lean muscle at L4L5 (-6.2%, p=.009) and L5S1 (-7.0%, p=.006) associated with the incidence of new disc herniation. Additionally, we observed reduced lumbar segment flexion-extension ROM for L2L3 (-17.2%, p=.006) and L3L4 (-20.5%, p=.02) following spaceflight, and furthermore that reduced ROM among the upper three lumbar segments (-24.1%, p=.01) associated with the incidence of disc herniation. Existing endplate pathology was most prevalent in the upper lumbar spine and associated with reduced segmental ROM (-20.5%, p=.02).ConclusionsIn conclusion from a 10-year study investigating the effects of spaceflight on the lumbar spine and risk for disc herniation, we found the incidence of lumbar disc herniation following spaceflight associates with compromised multifidus muscle quality and spinal segment kinematics, as well as pre-existing spinal endplate irregularities. These findings suggest differential effects of spinal stiffness and muscle loss in the upper versus lower lumbar spine regions that may specifically provoke risk for symptomatic disc herniation in the lower lumbar spine following spaceflight. Results from this study provide a unique longitudinal assessment of mechanisms and possible risk factors for developing disc herniations and related low back pain. Furthermore, these findings will help inform physiologic countermeasures to maintain spinal health in astronauts during long-duration missions in space.     

Extreme lateral lumbar disk herniation. Apropos of a series of 25 cases

Twenty-five cases of extreme lateral disc herniation (ELDH) were identified amongst 680 operated lumbar discs (3.7%). Their anatomical, radiological and clinical features are presented. They were found at all levels between L3 and S1. At the L5-S1 level 12 ELDH occurred amongst 253 disc herniations (5%), at the L4-L5 level, 8 ELDH amongst 400 herniations (2%), and at the L3-L4 level, 5 ELDH amongst 21 herniations (24%). No clinical features were encountered which could allow to differentiate between an ELDH and a classical disc herniation of the above level. Twenty-three patients underwent lumbar myelogram. This was normal in 6. In 12 it showed a slight shortening and widening of the above situated nerve root sleeve. The same abnormality can be found with downward migration of a classical herniation of the above situated disc or with a lateral recess stenosis. Twenty-five patients underwent computed tomography (CT.). In 24, the ELDH could be unequivocally identified. Disc material occupied the intervertebral foramen or the extravertebral space just beyond it, replacing the normal fat. In order to identify an ELDH, CT has to be done whenever myelogram is normal or equivocal. If the patient is to be investigated by CT only, slices through the intervertebral foramen and the disc below the clinically suspicious level have to be included. Operation in all cases consisted in total or partial unilateral laminectomy with facetectomy.     

Thermal quantitative sensory testing in lumbar disc herniation

The most frequent clinical presentation of sciatica suggests injury of sensor root fibers alone. To evaluate whether thermal quantitative sensory testing (QST) is applicable in the study of sensory dysfunction in lumbosacral disc herniations, 36 men and 30 women with L4/5 or L5/S1 disc herniations underwent thermal QST of the L4, L5, and Si dermatomes. For both levels of disc herniation, there was a significant difference for all temperature modalities, i.e., cold, warmth and heat pain, between all dermatomes as well as between the side of the herniated disc and the corresponding asymptomatic side. However, the proportion of herniated discs classified correctly was only 48% in patients with disc herniations at the L4/5 level, while it was 71% at the L5/S1 level. We conclude that thermal QST measurements reflect and document sensory dysfunction in patients with lumbosacral disc herniation. The method offers a new means both to study the time course of a spontaneous recovery of sensory dysfunction and to evaluate the result of different treatment options. However, thermal QST seems to have the same poor predictive value for identifying the anatomic location of a herniated lumbar disc as conventional electrophysiologic methods.     

Facet tropism: a comparison between far lateral and posterolateral lumbar disc herniations

STUDY DESIGN: An assessment of the difference in the degree of facet tropism and disc degeneration between far lateral and posterolateral lumbar disc herniations. OBJECTIVE: To investigate the effect of the difference in the degree of the facet tropism and disc degeneration with respect to the development of far lateral lumbar disc herniation and posterolateral lumbar disc herniation, and to compare the effect between the two types of herniations. SUMMARY OF BACKGROUND DATA: The effect of facet tropism on the development of posterolateral lumbar disc herniation has been investigated previously, but there has been no study on far lateral lumbar disc herniation. METHODS: Thirty-eight lumbar disc herniations (far lateral, n = 19; posterolateral, n = 19) were included this study. The degree of facet tropism and disc degeneration was measured at the herniated disc level by using magnetic resonance imaging. The results were compared to show any differences between the two types of lumbar disc herniations. RESULTS: There were significant differences in the degree of facet tropism (24.74 vs. 14.26, P = 0.004) and disc degeneration (23.92 vs. 15.08, P = 0.005) between the far lateral and posterolateral lumbar disc herniations. There was no significant correlation between the degree of facet tropism and the degree of disc degeneration in far lateral lumbar disc herniation (r = -0.369, P = 0.120). CONCLUSION: This results suggest that the differences in the degree of facet tropism and disc degeneration might be considered a key factor in distinguishing the development of far lateral lumbar disc herniation from that of posterolateral lumbar disc herniation.     

Diagnosis and microsurgical approach to far-lateral disc herniation in the lumbar spine

Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are increasingly recognized as a cause of spinal nerve root compression syndromes at the upper lumbar levels. Failure to diagnose and precisely localize these herniations can lead to unsuccessful surgical exploration or exploration of the incorrect interspace. If these herniations are diagnosed, they often cannot be adequately exposed through the typical midline hemilaminectomy approach. Many authors have advocated a partial or complete unilateral facetectomy to expose these herniations, which can lead to vertebral instability or contribute to continued postoperative back pain. The authors present a series of 25 patients who were diagnosed as having far lateral lumbar disc herniations and underwent paramedian microsurgical lumbar-disc excision. Twelve of these were at the L4-5 level, six at the L5-S1 level, and seven at the L3-4 level. In these cases, myelography is uniformly normal and high-quality magnetic resonance images may not be helpful. High-resolution computerized tomography (CT) appears to be the best study, but even this may be negative unless enhanced by performing CT-discography. Discography with enhanced CT is ideally suited to precisely diagnose and localize these far-lateral herniations. The paramedian muscle splitting microsurgical approach was found to be the most direct and favorable anatomical route to herniations lateral to the neural foramen. With this approach, there is no facet destruction and postoperative pain is minimal. Patients were typically discharged on the 3rd or 4th postoperative day. The clinical and radiographic characteristics of far-lateral lumbar-disc herniations are reviewed and the paramedian microsurgical approach is discussed.     

Speculum lumbar extraforaminal microdiscectomy

BACKGROUND CONTEXT: Public interest, monetary pressures and improving diagnostic techniques have placed an increasing emphasis on minimalism in lumbar disc excision. Current techniques include microlumbar discectomy and minimally invasive spinal surgery. Both are good techniques but may be painful, require a hospital stay and/or are not widely used because of difficulty acquiring the necessary skills. The author therefore developed a less invasive microscopic technique that may be performed on a consistent outpatient basis with easily acquired skills. PURPOSE: The purpose of this study was to describe a variant of minimally invasive lumbar disc excision, while assessing the effects on a small group of patients. STUDY DESIGN: The treatment protocol was a prospective community hospital-based case study designed to evaluate a less invasive method of excising herniated lumbar discs residing in the canal, foraminal or far lateral space. PATIENT SAMPLE: This study is comprised of 50 patients with all anatomic forms of lumbar disc herniations, inside or outside the canal, at all levels except the lumbosacral joint. OUTCOME MEASURES: Clinical results were measured by return to work time, the criteria of MacNab and by Prolo et al.'s economic and functional criteria. METHODS: Selection criteria included adult patients with intractable low back and leg pain, plus an imaging study revealing a lumbar disc herniation consistent with the patient's clinical presentation. Mean patient age was 48 years. The male:female ratio was approximately 2:1. All patients failed at least 3 weeks of conservative therapy. Herniations occurred from the L2-3 space through L4-5, with 30 herniations being within and 20 outside the spinal canal. Both contained and extruded/sequestered herniations were treated. Excluded from the study were patients with herniations inside the spinal canal at the L5-S1 level. Surgical approach was by microscopic speculum transforaminal route for discs residing both within and outside the lumbar canal. RESULTS: The initial 50 consecutive patients had successful technical operations performed on an outpatient basis by this less invasive technique. By the criteria of MacNab (Table 3), 84% (42 of 50) had an excellent or good result, returning to work at a mean time of 3.5 weeks. Per Prolo et al.'s economic scale, 72% were disabled at levels I and II before surgery. Postoperatively, 92% had improved to levels IV and V. Similarly, on his functional scale, 94% functioned at levels I and II before surgery, whereas 88% achieved levels IV and V after surgery. Eighty percent required no pain medications 1 week after surgery. The only complication was an L3 minor nerve root injury as it exited the L3-4 foramen. CONCLUSION: The author has described a minimally invasive technique for excising herniated discs that is applicable to all types of lumbar herniations, except for those residing in the canal at L5-S1. Clinical outcomes are comparable to those of other forms of discectomy.     

Herniated lumbar disc in patients over the age of fifty

Fifty patients ranging in age between 50-78 years (mean, 56) underwent surgery for a herniated lumbar disc between January 1986 and July 1988. All had objective clinical and radiographic evidence of a herniated disc. All had had failure during an appropriate period of conservative treatment. Far lateral herniation occurred in 8%, and 28% had disc herniations at L2 or L3. Surgical results were 64% excellent, 28% good, 6% fair, and 2% poor. Complications including urinary tract infection, wound infection, myocardial infarction, and pulmonary embolism were observed in 8% of patients. Lumbar disc herniation in the elderly is common. After thorough evaluation to exclude neoplasm or infection, decompression of neural structures can lead to 90% good to excellent results. Spinal stenosis must be carefully considered both preoperatively and intraoperatively. Also, a higher incidence of more cephalad lumbar herniations and far lateral herniations was observed in older patients.     

Posterior endoscopic discectomy (and other procedures)

Percutaneous approaches to lumbar discectomy were somewhat controversial, because of their limited indications. They have not proven to be as effective as standard open lumbar disc surgery, because of longer operating times and some technical problems in addressing all the different aspects of lumbar disc herniations. New percutaneous posterior procedures for lumbar disc disease have been described in the last few years, but the MicroEndoscopic Discectomy (MED) introduced by Foley and Smith in 1997 seems to be the most promising one. MED, and METR’x which evolved from it, . allow the surgeon to address not only contained lumbar disc herniations, but also free-fragment disc pathology and symptomatic lateral recess stenosis secondary to bony hypertrophy. The surgical technique is summarized and some preliminary clinical results of a prospective multicenter study with 13 months’ mean follow-up are presented.     

Surgical management of extreme lateral lumbar disc herniations: review of 138 cases

Extreme lateral disc herniations in the authors' series account for 10% of all lumbar herniations; 80% occurred at the L3, L4 and L4, L5 interspaces. The authors review the clinical findings in 138 patients and point to the characteristic features of the clinical syndrome. They compare the accuracy of various diagnostic studies and conclude that computed tomography is highly accurate and should be used before other diagnostic studies. Discography is still helpful as a confirmatory study in some cases, whereas myelography is particularly useful in disclosing other associated lesions. Analysis of the operative series revealed a high percentage of extruded fragments (60%) and a significant number of double herniations on the same side and at the same level (15%). These two findings may respectively preclude chemonucleolysis and microsurgery from the surgical management of extreme lateral herniations. Double herniations explain some discrepancies in the clinical picture and are emphasized as a potential source of error in diagnosis. The surgical technique allows exploration for herniations within the intervertebral canal as well as for extraforaminal herniations without sacrifice of the facet. Operative results are presented.     

Lumbar microdiscectomy

Lumbar disc herniations are seen frequently in pain management practices. Specialists are well versed in the nonsurgical treatments for lumbar radiculopathy. Although most disc herniations would resolve without the need for surgery; it should be considered when patients have refractory pain or motor deficit. The following article discusses the surgical treatment for lumbar disc herniation—microdiscectomy. Pertinent literature has been reviewed and the surgical outcomes are highlighted.     

Laser-assisted diskectomy performed by an internist resulting in cauda equina syndrome

An internist performed percutaneous laser-assisted diskectomies (PLADs) on a patient with a sequestrated disc and stenosis. Subspecialists who perform PLADs should be trained in patient selection and lumbar diskectomy techniques. Chymopapain, percutaneous nucleotome-assisted diskectomy, and PLADs are alternatives to microdiskectomy for the management of lumbar disc herniations. PLADs were performed at the L4-5/L5-S1 levels in a 38-year-old woman with magnetic resonance (MR)-documented L4-5 stenosis and disc disease. After PLADs, she developed a subacute cauda equina syndrome. Two months later, a neurosurgeon performed an L4-5 coronal hemilaminectomy with diskectomy. Within 6 postoperative weeks, she was neurologically intact. Only specialists trained in the selection, neurodiagnostic, and surgical management of lumbar disc disease should perform PLADs.