Migration patterns of herniated disc fragments: a study on 1,020 patients with extruded lumbar disc herniation

Hyperacute onset of adjacent segment disease with dorsally migrated herniated nucleus pulposus causing cauda equina syndrome: a case report

PURPOSE

To report the first case of hyperacute onset of adjacent segmental disease (ASD) with dorsally migrated herniated nucleus pulposus (HNP) causing cauda equina syndrome.

METHODS

A 55-year-old female complained of lower back pain with radiating pain in both lower extremities that had not responded to conservative treatment over the previous six months. Plain radiographs and magnetic resonance imaging (MRI) findings revealed degenerative spondylolisthesis with spinal stenosis at L3-4, L4-5, and a slight bulging disc at L2-3. The patient underwent decompressive total laminectomy and posterior fusion at L3-4 and L4-5. The stenotic symptoms improved significantly after surgery, and she was then discharged on postoperative day 7.

RESULTS

However, the patient visited the emergency department four days after discharge (postoperative day 11) complaining of sudden onset of bilateral lower extremity weakness and voiding and defecation difficulties. The follow-up MRI showed dorsally migrated huge HNP and a detached posterior longitudinal ligament (PLL) at L2-3, which was diagnosed as hyperacute onset of ASD causing cauda equina syndrome. The patient underwent an emergency second operation consisting of partial laminectomy at L2-3 with removal of the dorsally migrated huge HNP. After the second operation, the symptoms of cauda equina syndrome improved. One year after the second operation, the patient is doing well without recurrence of symptoms.

CONCLUSIONS

Our case showed that hyperacute onset of ASD with dorsally migrated huge HNP can cause cauda equina syndrome, even within 2 weeks after lumbar fusion surgery. Therefore, a high index of suspicion, timely diagnosis, and surgical treatment are needed to avoid the catastrophic neurologic complications in similar extremely rare cases.

Comparative analysis of percutaneous endoscopic interlaminar discectomy for highly downward-migrated disc herniation

OBJECTIVES

This study aimed to evaluate the clinical efficacy and safety of percutaneous endoscopic interlaminar discectomy (PEID) for treating highly downward-migrated disc herniation.

METHODS

We conducted a retrospective study on 39 patients with highly downward-migrated disc herniation who underwent PEID treatment between January 2015 and October 2020. The clinical outcomes, including the preoperative and postoperative visual analogue scale (VAS) for the back and leg, Oswestry Disability Index (ODI), and MacNab criteria for surgical success, were evaluated and compared to thirty-seven patients treated with posterior lumbar interbody fusion (PLIF).

RESULTS

The mean operation time of PEID was 93.00(77.00,110.00) min, while that of PLIF was 169.00(157.00,183.00) min. Continued improvement in both PEID and PLIF was observed in the VAS and ODI scores immediately after the surgery to the last follow-up. The VAS and ODI scores of PEID one week after surgery were significantly different from those of PLIF. One patient with recurrent lumbar disc herniation in the same segment improved after undergoing repeat PEID, two patients had dura tears, and conservative treatment helped relieve the symptoms. The overall percentage of patients with good to excellent results of PELD according to the modified MacNab criteria was 97.43%, while that of PLIF was 94.60%.

CONCLUSIONS

PEID has reliable efficacy and safety for treating highly downward-migrated disc herniation. And the long-term efficacy of PEID is comparable to PLIF. No severe complications occurred after surgery, and most patients' symptoms were relieved.

Percutaneous endoscopic lumbar discectomy for L5-S1 disc herniation based on image analysis and clinical findings: A retrospective review of 345 cases

The effect of spinal anatomical anomalies on the efficacy of percutaneous endoscopic lumbar discectomy (PELD) for disc herniation repair is unclear. This retrospective review aims to assess the safety and effectiveness of PELD for treating L5-S1 disc herniation with a range of characteristics and to determine the prevalence of lumbosacral transitional vertebrae (LSTV) anatomical anomalies to facilitate pre-surgical planning. From July 2005 to June 2019, 345 patients with L5-S1 disc herniations were treated with PELD. The primary outcome was 1-year postoperative visual analogue scale scores for low back and lower limb pain. The secondary outcomes included the surgical approach used, lumbosacral bony anomalies, presence of a ruptured disc or severely calcified disc, pediatric lumbar disc herniation, recurrent disc herniation management, and the long-term outcome. visual analogue scale scores for most patients were significantly improved after surgery. The prevalence of LSTVs was 4.05% (14/345 patients) in lumbar sacralization and 7.53% (26/345 patients) in sacral lumbarization. The prevalence of ruptured and severely calcified discs was 18.55% (64/345) and 5.79% (20/345), respectively. The prevalence of pediatric lumbar disc herniation was 2.02% (7/345). The recurrence rate was 4.34% (15/345). Two durotomy cases without sequelae and 8 cases of lower limb dysesthesia lasting longer than 3 months postoperatively were reported. PELD is safe and effective for treating L5-S1 disc herniation, including cases complicated by calcified lumbar disc herniation, disc rupture with migration, and the presence of LSTV. Appropriate imaging is essential to identify case-specific factors, including the prevalent LSTV anatomical anomalies, before surgery.

Trans-Tubular Translaminar Microscopic-Assisted Nucleotomy for Lumbar Disc Herniations in the Hidden Zone

STUDY DESIGN

A prospective cohort study in a high-flow spine center in Germany.

OBJECTIVES

This study aimed to evaluate clinical outcomes and complications of the trans-tubular translaminar microscopic-assisted percutaneous nucleotomy in cases of cranially migrated lumbar disc herniations (LDH).

METHODS

Between January 2013 and January 2018, 66 consecutive patients with cranio-laterally migrated LDH were operated upon. The following outcome measures were evaluated: (1) Visual Analog Scale (VAS) for leg and back pain; (2) Oswestry Disability Index (ODI) and Macnab´s criteria. All patients were operated upon with trans-tubular Translaminar Microscopic-assisted Percutaneous Nucleotomy (TL-MAPN). Perioperative radiographic and clinical evaluations were reported. The mean follow-up period was 32 months.

RESULTS

The mean age was 59 years. L4/L5 was the commonest affected level (27 patients). The mean preoperative VAS for leg pain was 6.44 (±2.06), improved to 0,35 (±0.59) postoperatively. Dural injury occurred in 1 patient, treated with dural patch. Improved neurological function was reported in 41/44 Patients (neurological improvement rate of 93%) at the final follow up. There was a significant improvement in the mean ODI values, from 50.19 ± 4.92 preoperatively to 10.14 ± 2.22 postoperatively (P < 0.001). Sixty four out of 66 patients (96%) showed an excellent or good functional outcome according to Macnab´s criteria. No recurrent herniations were observed.

CONCLUSION

The translaminar approach is a viable minimal invasive technique for cranially migrated LDH. The preservation of the flavum ligament is one of the main advantages of this technique. It is an effective, safe and reproducible minimally invasive surgical alternative in treatment of cranially migrated LDHs.

A New Grading System for Migrated Lumbar Disc Herniation on Sagittal Magnetic Resonance Imaging: An Agreement Study

Understanding the degree of disc migration is essential in order to diagnose, treat, and assess the prognosis of migrated lumbar disc herniation (LDH). Based on anatomical configuration, we developed a simple six-level grading system for migrated lumbar disc herniation. We aimed to evaluate whether the new grading system was reliable and could replace the previous grading system. We selected 101 cases from our database. Two independent raters evaluated the magnetic resonance images using each grading system. Interobserver, intraobserver, and inter-grading system agreements were assessed using kappa statistics. The most common migration pattern was low-grade inferior migration. Interobserver agreements between the two readers showed substantial agreement in the first and second assessments (k = 0.753 and 0.756, respectively). The intraobserver agreement of reader 1 revealed substantial agreement (k = 0.733), while that of reader 2 revealed almost perfect agreement (k = 0.829). The strengths of the agreements of the new grading system were higher than those of the Lee-Kim grading system. The two grading systems agreed almost perfectly for most measurements. The new grading system was reliable and feasible to determine migrated LDH grade. It allowed for a more intuitive, objective measurement and helped select surgical options.

Posterior epidural intervertebral disc migration and sequestration: A systematic review

Posterior epidural intervertebral disc migration and sequestration (PEIMS) is a rare and debilitating complication of degenerative disc disease. Radiological differential diagnosis is often challenging, complicating the accurate planning of appropriate treatment strategies. We systematically reviewed the literature on PEIMS, focusing on clinical-radiological features and available treatments. PubMed, Scopus, Web of Science, and Cochrane were searched to include studies reporting clinical data of patients with PEIMS. Clinical characteristics, treatment strategies, and functional outcomes were analyzed. We included 82 studies comprising 157 patients. Median age was 54 years (range, 19-91). PEIMSs occurred spontaneously (49.7%) or acutely in patients with underlying progressive degenerative disc disease (50.3%). The most common symptoms were lower-back pain (77.1%) and radiculopathy (66.2%), mainly involving the L5 nerve root (43.8%). PEIMSs were mostly detected at MRI (93%) and/or CT (7%), frequently located in the lumbar spine (81.5%). Median maximum PEIMS diameter was 2.4 cm (range, 1.2-5.0). Surgical debulking was completed in 150 patients (95.5%), sometimes coupled with decompressive laminectomy (65%) or hemilaminectomy (19.1%). Median follow-up time was 3 months (range, 0.5-36.0). Post-treatment symptomatic improvement was reported in 153 patients (97.5%), with total recovery in 118 (75.2%). All 7 patients (4.5%) who received conservative non-surgical management had total clinical recovery at ≤ 3 months follow-ups. PEIMS is a challenging entity that may severely quality-of-life in patients with degenerative disc disease. Surgical removal represents the gold standard to improve patient's functional status. Spine fusion and conservative strategies proved to be effective in some cases.

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

BACKGROUND CONTEXT

For 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.

PURPOSE

To 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 DESIGN

This is a prospective longitudinal study.

PATIENT SAMPLE

Our sample included a cohort of twelve astronaut crewmembers.

OUTCOME MEASURES

From 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.

METHODS

Advanced 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.

RESULTS

Half 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).

CONCLUSIONS

In 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.

PAIN INTENSITY AND FUNCTIONALITY AFTER PERCUTANEOUS ENDOSCOPIC DISCECTOMY: A RETROSPECTIVE COHORT STUDY

ABSTRACT Objectives To evaluate pain intensity and functional status before and 30 days following percutaneous lumbar endoscopic discectomy. Methods A retrospective cohort study that included patients who underwent percutaneous endoscopic discectomy from January 2019 to October 2020 at the Irmandade Santa Casa de Misericórdia Hospital, in Porto Alegre. The data were collected from the electronic medical records of the patients by two independent physicians. Clinical outcomes were assessed using visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. Results Forty-six patients with a mean age of 52.6 ± 15.8 years, 27 of whom (58.7%) were male, were evaluated. Regarding clinical outcomes, a statistically significant improvement was observed in the comparison between the pre- and 30-day postoperative VAS and ODI scores, with no significant difference in relation to sex. No peri- or postoperative complications were observed. All patients successfully completed surgery and were discharged after recovery from anesthesia. Conclusion There was a significant improvement in pain and functional status 30 days after percutaneous endoscopic discectomy performed to correct lumbar disc herniation, with no difference in relation to sex. In addition, no peri- or postoperative complications were observed. Future studies, with longer follow-up times, comparing clinical outcomes from the various techniques of percutaneous endoscopic discectomy are necessary. Level of evidence III; Retrospective comparative study.

Microscopic extra-laminar sequestrectomy (MELS) for the treatment of hidden zone lumbar disc herniation: report of the surgical technique, patient selection, and clinical outcomes

BACKGROUND

The area which located at the medial pedicle, posterior vertebral body and ventral hemilamina is defined as the hidden zone. Surgical management of hidden zone lumbar disc herniation (HZLDH) is technically challenging due to its difficult surgical exposure. The conventional interlaminar approach harbors the potential risk of post-surgical instability, while other approaches consist of complicated procedures with a steep learning curve and prolonged operation time.

OBJECTIVE

To introduce microscopic extra-laminar sequestrectomy (MELS) technique for treatment of hidden zone lumbar disc herniation and present clinical outcomes.

METHODS

Between Jan 2016 to Jan 2018, twenty one patients (13 males) with HZLDH were enrolled in this study. All patients underwent MELS (19 patients underwent sequestrectomy only, 2 patients underwent an additional inferior discectomy). The nerve root and fragment were visually exposed using MELS. The operation duration, blood loss, intra- and postoperative complications, and recurrences were recorded. The Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and the modified MacNab criteria were used to evaluate clinical outcomes. Postoperative stability was evaluated both radiologically and clinically.

RESULTS

The mean follow-up period was 20.95 ± 2.09 (18-24) months. The mean operation time was 32.43 ± 7.19 min and the mean blood loss was 25.52 ± 5.37 ml. All patients showed complete neurological symptom relief after surgery. The VAS and ODI score were significantly improved at the final follow-up compared to those before operation (7.88 ± 0.70 vs 0.10 ± 0.30, 59.24 ± 10.83 vs 11.29 ± 3.59, respectively, p < 0.05). Seventeen patients (81%) obtained an "excellent" outcome and the remaining four (19%) patients obtained a "good" outcome based the MacNab criteria. One patient suffered reherniation at the same level one year after the initial surgery and underwent a transforaminal endoscopic discectomy. No major complications and postoperative instability were observed.

CONCLUSIONS

Our observation suggest that MELS is safe and effective in the management of HZLDH. Due to its relative simplicity, it comprises a flat surgical learning curve and shorter operation duration, and overall results in reduced disturbance to lumbar stability.

Effect of Core Stabilizing Training on Young Individuals Presenting Different Stages of Degenerative Disc Disease-Preliminary Report

The aim of this study was to assess the efficacy of stabilizing training for the deep core muscles of the lumbar spine in subjects with degenerative disc disease. This study was conducted on 38 participants. The participants were divided into two groups: the extrusion group (EXT, n = 17) and the protrusion group (PRO, n = 21). All the subjects underwent a four-week-long core stability exercise-based treatment (five sessions/week). Clinical outcome measures were assessed pre-intervention (pre), post-intervention (post) and four weeks after the intervention (follow-up). The primary outcome measures were the spinal range of motion (ROM; Spinal Mouse^® device) and the Oswestry Disability Index (ODI). In the PRO group, the ROM decreased from 88.52° pre-intervention to 83.33° post-intervention and to 82.82° at follow-up (p = 0.01), while the ODI decreased from 16.14 points pre-intervention to 6.57 points post-intervention, with 9.42 points at follow-up (p < 0.01). In the EXT group, the ROM decreased from 81.00° pre-intervention to 77.05° post-intervention, then increased to 77.94° at follow-up (p = 0.03), while the ODI decreased from 22.58 points pre-intervention to 15.41 points post-intervention and to 14.70 points at follow-up (p < 0.001). Although the stabilizing exercise sessions improved the clinical outcomes in each group, we cannot make conclusions as to whether the type of intervertebral disc damage significantly affects the results of stabilizing exercise-based treatment.

Evaluation of Cartilaginous Endplate Degeneration Based on Magnetic Resonance Imaging

In order to carry out the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging (MRI), this paper retrospectively analyzed the MRI data from 120 cases of patients who were diagnosed as lumbar intervertebral disc degeneration and underwent MRI examinations in the designated hospital of this study from June 2018 to June 2020. All cases underwent conventional sagittal and transverse T1WI and T2WI scans, and some cases were added with sagittal fat-suppression T2WI scans; then, the number of degenerative cartilaginous endplates and its ratio to degenerative lumbar intervertebral discs were counted and calculated, and the T1WI and T2WI signal characteristics of each degenerative cartilage endplate and its correlation with cartilaginous endplate degeneration were summarized, compared, and analyzed to evaluate the cartilaginous endplate degeneration by those magnetic resonance information. The study results show that there were 33 cases of cartilaginous endplate degeneration, accounting for 27.50% of all those 120 patients with lumbar intervertebral disc degeneration (54 degenerative endplates in total), including 9 cases with low T1WI and high T2WI signals, 5 cases with high T1WI and low T2WI signals, 12 cases with high and low mixed T1WI and high or mixed T2WI signals, and 4 cases with both low T1WI and T2WI signals. Therefore, MRI scanning can clearly present the abnormal signals of lumbar intervertebral disc and cartilaginous endplate degeneration, accurately identity their lesion locations, and type their degenerative characteristics, which may be best inspection method for the evaluation of cartilaginous endplate degeneration in the early diagnosis of intervertebral disc degeneration. The study results of this paper provide a reference for further researches on the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging.

ANALYSIS OF THE RELIABILITY OF THE LEE CLASSIFICATION FOR LUMBAR DISC HERNIATIONS

ABSTRACT Objective To evaluate the intra- and interobserver reliability of the Lee et al. classification for migrated lumbar disc herniations. Methods In 2018, Ahn Y. et al. demonstrated the accuracy of this classification for radiologists. However, magnetic resonance images are often interpreted by orthopedists. Thus, a cross-sectional study was conducted by evaluating the magnetic resonance images of 82 patients diagnosed with lumbar disc herniation. The images were evaluated by 4 physicians, 3 of whom were spinal orthopedic specialists and 1 of whom was a radiologist. The intra- and interobserver analysis was conducted using the percentage of concordance and the Kappa method. Results The report of the classifications used by the four observers had a higher proportion of “zone 3” and “zone 4” type classifications in both evaluation moments. The most affected anatomical levels were L5-S1 (48.2%) and L4-L5 (41.4%). The intra- and interobserver concordance, when comparing both moments evaluation of the complementary examinations of the participants involved, was classified as moderate and very good. Conclusions Lee’s classification presented moderate to very good intra- and interobserver reliability for the evaluation of migrated lumbar disc herniation. Level of evidence II; Retrospective Study.

Missing Disc Fragment: A Rare Surgical Experience

About 35%-72% of lumbar disc herniations are associated with fragment migration. However, the posterior epidural migration is rare. We present a strange situation encountered during surgical decompression of the posterior migrated fragment. A 72-year-old male presented with a history of pain radiating to the left lower limb and Grade 3 power of the extensor hallucis longus. Magnetic resonance imaging revealed a prolapsed intervertebral disc and a possible posterior epidural migration of disc fragment. Routine surgical steps for microdiscectomy were followed after confirmation of level using fluoroscopy. However, the extruded disc fragment was not seen, and both exiting and traversing roots were free with adequate mobility. After extensively searching for a disc in the spinal canal, suction fluid was filtered through a surgical mop used as a sieve. Material collected was sent for histopathological study. Biopsy report confirmed material filtered was indeed the intervertebral disc. Thus, accidental suction of disc material in case of the posterior epidural migrated disc is a possibility, and we should be vigilant about this scenario to avoid disaster.

Early Clinical Outcomes of Percutaneous Endoscopic Lumbar Discectomy for L4-5 Highly Down-Migrated Disc Herniation: Interlaminar Approach Versus Transforaminal Approach

OBJECTIVE

This study is a retrospective evaluation of patients with L4-5 highly down-migrated lumbar disc herniation (LDH) operated with interlaminar endoscopic lumbar discectomy (IELD) versus transforaminal endoscopic lumbar discectomy (TELD).

METHODS

From January 2015 to December 2018, 77 patients with L4-5 highly down-migrated LDH were divided into 2 groups according to different surgical approaches. There were 40 patients who underwent IELD, and 37 patients who underwent TELD. The operation time, hospital stay, Oswestry Disability Index, clinical outcome according with modified MacNab criteria, Visual Analog Scale (VAS) scores, and complications were compared between the IELD and TELD groups.

RESULTS

Seventy-seven patients were included, 40 and 37 patients underwent IELD and TELD, respectively. The IELD and TELD groups both achieved a significant improvement in Oswestry Disability Index, back and leg VAS scores, and clinical outcome postoperation. Mean operating and x-ray times during operation were significantly shorter in the IELD group than in the TELD group (41.8 vs. 50.3, 1.8 vs. 13.7). There were 3 patients who experienced recurrence in the IELD group and 2 in the TELD group. In the TELD group, there were 3 patients who required revision surgery due to incompletely removed disc fragment. All patients in the IELD group were treated successfully. There was no other complication in these cases.

CONCLUSIONS

Both IELD and TELD could be a good alternative option for highly down-migrated LDH in L4-L5. IELD may have advantages in operation time and x-ray times during operation compared with TELD.

Suprapedicular Retrocorporeal Technique of Transforaminal Full-Endoscopic Lumbar Discectomy for Highly Downward-Migrated Disc Herniation

OBJECTIVE

Anatomical barriers (e.g., pedicles, narrow foramina) can hinder direct access to, and removal of, disc fragments that have migrated far downward. Using transforaminal full-endoscopic lumbar discectomy (FELD), we devised a modified technique, the suprapedicular retrocorporeal approach, for herniations in which the disc has migrated to the axilla of the traversing nerve roots. In the present report, we have described our preliminary results.

METHODS

Soft, highly downward-migrated disc herniation was treated with transforaminal FELD through the suprapedicular retrocorporeal approach in 22 patients from June 2017 to May 2019. The clinical outcomes were evaluated, including the preoperative and postoperative visual analog scale scores for the back and leg, Oswestry disability index, and MacNab criteria for surgical success.

RESULTS

The affected discs were at L4-L5 in 14 patients, L3-L4 in 6 patients, and L5-S1 in 2 patients. In each case, the affected disc was successfully removed using the suprapedicular retrocorporeal approach. The mean follow-up was 18.1 ± 5.7 months. The mean visual analog scale scores for back and leg pain improved significantly (P < 0.05 for both). The mean Oswestry disability index had decreased from 62.5 ± 14.2 preoperatively to 10.5 ± 5.9 postoperatively (P < 0.05). Using the MacNab criteria, 13 patients reported excellent outcomes and 9, good outcomes. No complications or recurrence developed during follow-up.

CONCLUSIONS

The suprapedicular retrocorporeal technique is a feasible and effective surgical option in transforaminal FELD for the treatment of herniation in which the disc has migrated to the axilla of the traversing nerve roots.

Outcomes of Discectomy in Young Adults With Large Central Lumbar Disc Herniations Presenting With Predominant Leg Pain

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Discectomy alone or discectomy with fusion have been 2 polarized options in the management of large lumbar disc herniations presenting with leg-dominant pain in young patients. The objective of the study was to evaluate the outcomes of discectomy in young patients with large central lumbar disc herniation (CLDH) presenting with predominant leg pain.

MATERIAL AND METHODS

Young patients (<45 years) presenting with predominant leg pain and MRI confirmed diagnosis of CLDH between April 2007-January 2017 were included in the study. All patients underwent tubular microdiscectomy. Outcomes of surgery were evaluated using visual analogue score (VAS) for leg and back pain, Oswestry Disability Index (ODI), and Macnab's criteria.

RESULTS

Ninety patients fulfilled the inclusion criteria. The mean age of patients was 34.9 years (range 19-45 years). Mean follow-up was 5.09 years (range 2-10 years). The incidence of CLDH in young adults was 30% and incidence among all "operated" lumbar disc herniations was 15.9%. The mean VAS for leg pain improved from 7.48 ± 0.9 to 2.22 ± 0.84 (P < .05) and the mean ODI changed from 60.53 ± 7.84 to 18.33 ± 6.20 (P < .05). Fifty-nine patients (65.6%) reported excellent, 25 patients (27.8%) reported good, 3 patients each (3.3%) as fair and poor outcomes respectively.

CONCLUSION

Discectomy alone for CLDH with predominant leg pain is associated with high success rate and low need for a secondary surgical procedure. Patient selection in terms of leg-dominant pain may be the main attribute for lower incidence of recurrence, postoperative back-pain, and instability needing a secondary procedure. Minimally invasive discectomy may provide an added advantage of preserving normal spinal anatomy, thus minimizing the need for primary spinal fusion in these patients.

Percutaneous Isthmus Foraminoplasty and Full-Endoscopic Lumbar Discectomy for Very Highly Upmigrated Lumbar Disc Herniation: Technique Notes and 2 Years Follow-Up

OBJECTIVE

To report the technical notes and clinical outcome of percutaneous isthmus foraminoplasty and full-endoscopic lumbar discectomy (PIF-FELD) for the treatment of very highly upmigrated lumbar disc herniation (VHUM-LDH).

PATIENTS AND METHODS

From January 2014 to December 2017, 16 patients with VHUM-LDH underwent PIF-FELD surgery. A 10-mm-diameter semi-open foraminoplasty was performed on the dorsal side of the upper intervertebral foramen with lateral isthmus resection by a safe trephine system, in which the facet joint was not injured. Full-endoscopic transforaminal fragmentectomy in the spinal canal and discectomy in the intervertebral space were performed simultaneously. Magnetic resonance imaging of the lumbar spine was reexamined on the second day and 3 months after the operation to evaluate the completeness of the disc fragmentectomy and nerve decompression. The patients were followed up on the visual analog scale (VAS) of lumbar pain and leg pain and Oswestry Disability Index on the second day, 3 months, 6 months, 1 year, and 2 years after operation. The MacNab score and nerve root function recovery were evaluated at 2 years postoperative follow-up.

RESULTS

All operations were successfully completed without any change in the surgical method. During the operation, 5 patients were found to have a single sequestered fragment, and the remaining 11 patients had multiple sequestered fragments. There were no complications (e.g., dural tear and nerve injury) during the operation, and no complications (e.g., infection, cerebrospinal fluid leakage, exacerbation of nerve root function injury, and recurrence of intervertebral disc herniation) occurred. Postoperative reexamination of lumbar magnetic resonance imaging in all patients showed complete disc fragmentectomy and adequate nerve decompression. The postoperative low back pain VAS and leg pain VAS scores and Oswestry Disability Index on the second day, 3 months, 6 months, 1 year, and 2 years after operation were significantly improved compared with preoperatively (P < 0.01). At 2 years follow-up, the sensation and muscular strength of the affected nerve root innervation area were significantly restored (P < 0.05), but tendon reflex function was not significantly restored (P > 0.05). At 2 years follow-up, MacNab scores included 6 excellent, 9 good, and 1 fair.

CONCLUSIONS

PIF-FELD is a safe and effective minimally invasive spine surgery technique for VHUM-LDH.

Autogenic mesenchymal stem cells for intervertebral disc regeneration

PURPOSE

A systematic review of the literature was conducted to clarify the outcomes of autologous mesenchymal stem cells (MSC) injections for the regeneration of the intervertebral disc (IVD).

METHODS

The following databases were accessed: PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar bibliographic databases. Articles including previous or planned surgical interventions were excluded. Only articles reporting percutaneous autologous MSC injection to regenerate IVD in humans were included. We referred to the Coleman Methodology Score for the methodological quality assessment. The statistical analysis was performed using Review Manager Software 5.3.

RESULTS

After the databases search and cross-references of the bibliographies, seven studies were included in the present work. The funnel plot detected low risk of publication bias. The Coleman Methodology Score reported a good result, scoring 61.07 points. A total of 98 patients were enrolled, with 122 treated levels. All the patients underwent conservative therapies prior to injection. A remarkable improvement in the quality of life were reported after the treatment. The average Oswestry Disability Index (ODI) improved from "severe disability" to "minimal disability" at one year follow-up. The visual analogue scale (VAS) showed an improvement of ca. 30% at one year follow-up. Only one case of herniated nucleus pulposus was reported. No other adverse events at the aspiration or injection site were observed.

CONCLUSIONS

This systematic review of the literature proved MSC injection to be a safe and feasible option for intervertebral disc regeneration in the early-degeneration stage patients. Irrespective of the source of the MSCs, an overall clinical and radiological improvement of the patients has been evidenced, as indeed a very low complication rate during the follow-up.

Degenerative Disc Disease Mimicking Spondylodiscitis with Bilateral Psoas Abscesses

BACKGROUND

Sequestered disc fragments may present as a lesion with peripheral enhancement on magnetic resonance imaging. When located in the psoas muscle compartment, this finding could mimic an abscess.

CASE DESCRIPTION

We describe a case of a 52-year-old man who returned from Togo after 2 years of living in precarious conditions. He was afebrile and complaining of lumbar back pain. The magnetic resonance imaging showed L3 and L4 vertebral body enhancement with bilateral psoas lesions in continuity with the disc space, suggesting spondylodiscitis with a differential diagnosis of inflammatory herniated disc. A computed tomography-guided biopsy of the right psoas lesion was performed to rule out spondylodiscitis. Histology was compatible with extruded disc material.

CONCLUSION

Herniated disc fragments should be considered as a differential diagnosis of psoas abscesses. Coronal plane images may show the continuity of bilateral herniated disc fragments, mimicking psoas abscesses.

Acupuncture and Neural Mechanism in the Management of Low Back Pain-An Update

Within the last 10 years, the percentage of low back pain (LBP) prevalence increased by 18%. The management and high cost of LBP put a tremendous burden on the healthcare system. Many risk factors have been identified, such as lifestyle, trauma, degeneration, postural impairment, and occupational related factors; however, as high as 95% of the cases of LBP are non-specific. Currently, LBP is treated pharmacologically. Approximately 25 to 30% of the patients develop serious side effects, such as drowsiness and drug addiction. Spinal surgery often does not result in a massive improvement of pain relief. Therefore, complementary approaches are being integrated into the rehabilitation programs. These include chiropractic therapy, physiotherapy, massage, exercise, herbal medicine and acupuncture. Acupuncture for LBP is one of the most commonly used non-pharmacological pain-relieving techniques. This is due to its low adverse effects and cost-effectiveness. Currently, many randomized controlled trials and clinical research studies have produced promising results. In this article, the causes and incidence of LBP on global health care are reviewed. The importance of treatment by acupuncture is considered. The efforts to reveal the link between acupuncture points and anatomical features and the neurological mechanisms that lead to acupuncture-induced analgesic effect are reviewed.

Downward Laminotomy Technique for Hidden Zone Foraminal Disk Herniations: Technical Notes and Preliminary Results

INTRODUCTION

Hidden zone foraminal herniations are among the more rare forms of herniations. As exploration is difficult, and there is a close relationship between the nerve root and pedicle, many surgical approaches have been proposed. The aim of this study was to describe downward laminotomy as a new approach to these herniations.

MATERIALS AND METHODS

A downward laminotomy technique was used in 5 cases with hidden zone foraminal disk herniation with no extension to the intervertebral disk space.

RESULTS

The herniated disk fragment was located at L4-L5 in 4 cases and at L3-L4 in 1 case. Mean visual analog scale scores reduced from preoperative 8.2 to 2.1 postoperatively. The allodynia was resolved in two months.

CONCLUSIONS

It was concluded that downward laminotomy provides a safe, less risky, and minimally invasive approach to hidden zone foraminal disk herniations.

Grading system for migrated lumbar disc herniation on sagittal magnetic resonance imaging: an agreement study

PURPOSE

Migrated lumbar disc herniations (LDHs) in the sagittal plane are common. Disc migration grading can be applied as a useful measurement tool in the diagnosis, treatment, and outcome evaluation of migrated LDH. No study has evaluated the reliability of migrated LDH grading. We evaluated the reliability and functionality of the current magnetic resonance imaging (MRI) grading system for migrated LDH.

METHODS

We assessed a six-level grading system developed based on sagittal MRI and graded according to the direction (rostral and caudal) and degree (low, high, and very high) of disc migration. One-hundred and one migrated LDHs treated with minimally invasive endoscopic discectomy were analyzed independently by two experienced radiologists. Intraobserver and interobserver agreements were assessed by kappa statistics.

RESULTS

The most common migrated LDH grade was grade 4 (30.94%; caudal, low-grade migration). Rostral and caudal migrations were more common in the upper and lower lumbar levels, respectively. Interobserver agreement in the grading of migrated LDH was good at both the first (kappa = 0.737) and second assessment (kappa = 0.657). The intraobserver agreement for reader 1 was very good (kappa = 0.827) and for reader 2 was good (kappa = 0.620).

CONCLUSIONS

The current grading system for migrated LDH was found to be reliable and functional with good interobserver and intraobserver agreement. It may be useful in the interpretation of disc migration patterns and outcomes of various minimally invasive surgical procedures.

The radiological distance between the lumbar pedicle and laminar edges

INTRODUCTION

Lumbar foraminal inner zone herniations are challenging cases, for which there are variety of approaches. However, there is no information about the distance between these herniations and the edges of the respective lamina. The aim of this study was to measure the distance between the inferomedial aspect of lumbar pedicles and laminar edges.

MATERIALS AND METHODS

The lumbar CT images of 30 cases were reviewed. The distances between the edges of the lamina and the inferomedial aspects of the respective pedicles were measured. The study was performed on L3, L4, and L5 lumbar vertebrae on both sides.

RESULTS

The mean distance between the upper edge of the lamina and the inferomedial aspect of the respective pedicle was found to be 10.8 ± 3.5, 11.6 ± 2.4, and 14.1 ± 2.3 mm on the left side, and 11.1 ± 4.4, 12.0 ± 2.5, and 13.8 ± 3.2 mm on the right side of L3, L4, and L5 vertebrae. The mean distance between the inferior edge of the lamina and the inferomedial aspect of the respective pedicle was found to be 23.8 ± 4.2, 19.3 ± 3.5, and 11.6 ± 2.9 mm, on the left side, and 23.9 ± 3.2, 19.1 ± 3.7, and 12.4 ± 2.8 mm on the right side of L3, L4, and L5 vertebrae. There was no statistically significant difference between values of the left and right sides (p > 0.05).

CONCLUSION

This study revealed that distance between the inferomedial aspect of lumbar pedicles and the superior edge of the same lamina was shorter than the distance between the inferomedial aspect of lumbar pedicles and the inferior edge of the same lamina at L3 and L4 level. It was concluded that this shorter distance could be taken into consideration during surgery on inner zone 1 foraminal herniations.

Analysis of Migration Patterns of Disk Fragments and Contributing Factors in Extruded Lumbar Disk Herniation

BACKGROUND

The exact location of migrated extruded lumbar disk fragments is an important consideration in selecting a treatment plan. However, few descriptive reports of the migration pattern of extruded lumbar disk fragments are available.

OBJECTIVE

To examine the distribution of disk fragments and possible contributing factors that affect their migration.

DESIGN

Retrospective descriptive study.

SETTING

Tertiary university outpatient and inpatient clinic.

PATIENTS

A total of 164 patients diagnosed with a symptomatic extruded lumbar disk from January 2011 to December 2012.

METHODS

Lumbar spine magnetic resonance imaging scans of patients were retrospectively reviewed. The term "migration" was defined as the horizontal and vertical displacement of extruded material away from the opening in the annulus through which the material has extruded. Migration of the disk material was recorded in both the horizontal and vertical plane. In the horizontal plane, migration was recorded as central, paracentral, subarticular, or foraminal. In the vertical plane, migration was recorded as rostral or caudal.

MAIN OUTCOME MEASUREMENTS

The pattern of migration and the associated factors (age and the level of herniation) were analyzed.

RESULTS

Rostral and caudal migration was observed in 27% (95% confidence interval [CI], 21%-35%) and 73% (95% CI, 66%-79%) of the patients. Central, paracentral, subarticular, and foraminal migration was observed in 6% (95% CI, 3%-11%), 67% (95% CI, 60%-74%), 18% (95% CI, 13%-25%), and 9% (95% CI, 5%-14%) of the patients, respectively. A significant increase was observed in the incidence of rostral migration with increasing age (P = .048). A significant association was also noted between migration in the horizontal plane and increasing age (P = .01). A significant increase occurred in the incidence of foraminal extrusion with increasing age (P = .01). A significant association was found between migration in the vertical plane and horizontal plane; in patients with foraminal herniations, migration was always rostral (P < .001).

CONCLUSION

The migration of extruded lumbar disk materials follows some general patterns. The results of this study may help spine interventionists and surgeons choose appropriate treatments for patients who have radiculopathy associated with lumbar disk extrusions.

LEVEL OF EVIDENCE

IV.

Orientation of the facet joints in degenerative rotatory lumbar scoliosis: an MR study on 52 patients

BACKGROUND

Because of a degenerative component, degenerative rotatory scoliosis seems different from congenital and idiopathic subtypes of the disease. This study aims to examine the orientation of facet joints, as a known cause of degeneration, in patients with degenerative rotatory scoliosis.

METHODS

Lumbar magnetic resonance (MR) images and plain radiographs of 52 symptomatic patients (mean age, 50.17 years) with degenerative rotatory lumbar scoliosis (mean curve, 19.22 degrees) and 50 healthy individuals were reviewed. Facet joint angles in rotated segments and the minimum neural foramen width at all lumbar levels were measured by three observers and the average was recorded.

RESULTS

The maximum vertebral rotation was most frequent at L4-L5 (75 %), and the majority was of type I (84.6 %) according to the Nash-Moe classification. At all lumbar spinal levels the mean facet joint angles were significantly higher on the side of rotation (L2-L3, 57.92 degrees; L3-L4, 45.00 degrees; L4-L5, 43.88 degrees) compared to those on the contralateral side (L2-L3, 20.42 degrees; L3-L4, 15.48 degrees; L4-L5, 13.12 degrees) and in controls (L2-L3, 30.21 degrees; L3-L4, 40.81 degrees; L4-L5, 45.20 degrees) (p < 0.001 for all comparisons). The mean facet joint angle increased significantly from L4-L5 to L2-L3 in cases and reversely in controls. The mean minimum neural foramen width was 1.29 ± 0.85 mm on the side of rotation, 5.50 ± 1.09 mm on the contralateral side, and 6.78 ± 1.75 mm in controls (p < 0.001).

CONCLUSIONS

Substantial asymmetries and abnormal orientations in facet joints were documented in patients with degenerative rotatory lumbar scoliosis. Such asymmetries may adversely affect neural foramen width.

Clinical and Radiological Characteristics of Lumbosacral Lateral Disc Herniation in Comparison With Those of Medial Disc Herniation

Lateral disc herniation (foraminal and extra foraminal) has clinical characteristics that are different from those of medial disc herniation (central and subarticular), including older age, more frequent radicular pain, and neurologic deficits. This is supposedly because lateral disc herniation mechanically irritates or compresses the exiting nerve root or dorsal root ganglion inside of a narrow canal more directly than medial disc herniation. The purpose of this study was to investigate clinical and radiological characteristics of lateral disc herniation in comparison with medial disc herniation. The 352 subjects diagnosed with localized lumbosacral disc herniation and followed up for at least 12 months after completion of treatment were included and divided into medial and lateral disc herniation groups, according to the anatomical location of the herniated disc in axial plain of magnetic resonance image. Clinical and radiological data were obtained and compared between the two groups. The lateral group included 74 (21%) patients and the medial group included 278 (79%). Mean age of the lateral group was significantly higher than that in the medial group. The lateral group showed a significantly larger proportion of patients with radiating leg pain and multiple levels of disc herniations than the medial group. No significant differences were found in terms of gender, duration of pain, pretreatment numeric rating scale, severity of disc herniation (protrusion and extrusion), and presence of weakness in leg muscles. The proportion of patients who underwent surgery was not significantly different between the 2 groups. However, the proportion of patients who accomplished successful pain reduction after treatment was significantly smaller in the lateral than in the medial group. In conclusion, patients with lateral disc herniation were older and had larger proportion of radiating leg pain than those with medial disc herniation. Lateral disc herniation was more associated with multiple disc herniations and worse clinical outcomes after treatment than medial disc herniation.

Supine spinal magnetic resonance imaging with straightened lower extremities in spondylolisthesis: a comparison with the conventional technique

OBJECTIVES

To compare the degree of slip in spondylolisthesis on supine magnetic resonance (MR) images obtained with flexed and straightened lower extremities.

METHODS

Supine spinal MR studies were performed in 100 cases of symptomatic spondylolisthesis with flexed and then straightened lower extremities. The angle of lumbar lordosis (by Cobb's method) and the degree of slip (by Taillard's method) were compared between the two sets of images.

RESULTS

The mean angle of lumbar lordosis increased from 51.65±8.57° on MR images with flexed lower limbs to 57.39±9.05° on MR images with straightened lower limbs (p<0.001; mean percent increase: 11.51%). Similar change was also observed for the mean degree of slip (from 25.80±7.74% to 28.68±7.93%, p<0.001; mean percent increase: 12.60%). After MR imaging with straightened lower extremities 22 out of 54 initially grade I cases had grade II disease (p<0.001).

CONCLUSIONS

Supine magnetic resonance imaging with straightened lower extremities detects higher degree of slippage in symptomatic patients with spondylolisthesis compared to conventional MRI with flexed lower extremities.

Use of magnetic resonance imaging to identify outcome predictors of caudal epidural steroid injections for lower lumbar radicular pain caused by a herniated disc

Objective

We used lumbar magnetic resonance image (MRI) findings to determine possible outcome predictors of a caudal epidural steroid injection (CESI) for radicular pain caused by a herniated lumbar disc (HLD).

Methods

Ninety-one patients with radicular pain whose MRI indicated a HLD were enrolled between September 2010 and July 2013. The CESIs were performed using ultrasound (US). A responder was defined as having complete relief or at least a 50% reduction of pain as assessed by the visual analog scale (VAS) and functional status on the Roland Morris Disability Questionnaire (RMDQ); responder (VAS n=61, RMDQ n=51), and non-responder (VAS n=30, RMDQ n=40). MRI findings were analyzed and compared between the two groups with regard to HLD level, HLD type (protrusion or exclusion), HLD zone (central, subarticular, foraminal, and extraforaminal), HLD volume (mild, moderate, or severe), relationship between HLD and nerve root (no contact, contact, displaced, or compressed), disc height loss (none, less than half, or more than half ), and disc degeneration grade (homogeneous disc structure or inhomogeneous disc structure-clear nucleus and height of intervertebral disc).

Results

A centrally located herniated disc was more common in the responder group than that in the non-responder group. Treatment of centrally located herniated discs showed satisfactory results. (VAS p=0.025, RMDQ p=0.040). Other factors, such as HLD level, HLD type, HLD volume, relationship to nerve root, disc height loss, and disc degeneration grade, were not critical.

Conclusion

The HLD zone was significant for pain reduction after CESI. A centrally located herniated disc was a predictor of a good clinical outcome.

End plate disproportion and degenerative disc disease: a case-control study

Study Design

Case-control.

Purpose

To determine whether a disproportion between two neighboring vertebral end plates is associated with degenerative disc disease.

Overview of Literature

Recently, it has been suggested that disproportion of the end plates of two adjacent vertebrae may increase the risk of disc herniation.

Methods

Magnetic resonance (MR) images (n=160) with evidence of grades I-II lumbar degenerative disc disease (modified Pfirrmann's classification) and normal MR images of the lumbar region (n=160) were reviewed. On midsagittal sections, the difference of anteroposterior diameter of upper and lower end plates neighboring a degenerated (in the case group) or normal (in the control group) intervertebral disc was calculated (difference of end plates [DEP]).

Results

Mean DEP was significantly higher in the case group at the L5-S1 level (2.73±0.23 mm vs. 2.21±0.12 mm, p=0.03). Differences were not statistically significant at L1-L2 (1.31±0.13 mm in the cases vs. 1.28±0.08 mm in the controls, p=0.78), L2-L3 (1.45±0.12 mm in the cases vs. 1.37±0.08 mm in the controls, p=0.58), L3-L4 (1.52±0.13 mm in the cases vs. 1.49±0.10 mm in the controls, p=0.88), and L4-L5 (2.15±0.21 mm in the cases vs. 2.04±0.20 mm in the controls, p=0.31) levels. The difference at the L5-S1 level did not remain significant after adjusting for body mass index (BMI), which was significantly higher in the patients.

Conclusions

End plate disproportion may be a significant, BMI-dependent risk factor for lumbar degenerative disc disease.

Analysis of Inadvertent Intradiscal Injections during Lumbar Transforaminal Epidural Injection

BACKGROUND

Recently, there have been several case reports and retrospective studies about the incidence of intradiscal (ID) injection during transforaminal epidural steroid injection (TFESI). Inadvertent ID injection is not a rare complication, and it carries the risk of developing diskitis, although there has been no report of diskitis after TFESI. We prospectively evaluated the incidence of inadvertent ID injection during lumbar TFESI and analyzed the contributing factors.

METHODS

Ten patients received 2-level TFESI, and the remaining 229 patients received 1-level TFESI. When successful TFESI was performed, 2 ml of contrast dye was injected under real-time fluoroscopy to check for any inadvertent ID spread. A musculoskeletal radiologist analyzed all magnetic resonance images (MRIs) of patients who demonstrated inadvertent ID injection. When reviewing MRIs, the intervertebral foramen level where ID injection occurred was carefully examined, and any anatomical structure which narrowing the foramen was identified.

RESULTS

Among the 249 TFESI, we identified 6 ID injections; thus, there was an incidence of 2.4%. Four patients had isthmic spondylolisthesis, and the level of spondylolisthesis coincided with the level of ID injection. We further examined the right or left foramen of the spondylolisthesis level and identified the upward migrated disc material that was narrowing the foramen.

CONCLUSIONS

Inadvertent ID injection during TFESI is not infrequent, and pain physicians must pay close attention to the type and location of disc herniation.