Unilateral facetectomy approach for lateral lumbar disc herniation

Lumbar vertebropexy after unilateral total facetectomy

BACKGROUND CONTEXT

Posterior decompression with spinal instrumentation and fusion is associated with well-known complications. Alternatives that include decompression and restoration of native stability of the motion segment without fusion continue to be explored, however, an ideal solution has yet to be identified.

PURPOSE

The aim of this study was to test two different synthetic lumbar vertebral stabilization techniques that can be used after unilateral total facetectomy.

STUDY DESIGN

Biomechanical cadaveric study.

METHODS

Twelve spinal segments were biomechanically tested after unilateral total facetectomy and stabilized with a FiberTape cerclage. The cerclage was pulled through the superior and inferior spinous process (interspinous technique) or through the spinous process and around both laminae (spinolaminar technique). The specimens were tested after (1) unilateral total facetectomy, (2) interspinous vertebropexy and (3) spinolaminar vertebropexy. The segments were loaded in flexion-extension (FE), lateral shear (LS), lateral bending (LB), anterior shear (AS) and axial rotation (AR).

RESULTS

Unilateral facetectomy increased native ROM in FE by 10.6% (7.6%-12.6%), in LS by 25.8% (18.7%-28.4%), in LB 7.5% (4.6%-12.7%), in AS 39.4% (22.6%-49.2%), and in AR by 27.2% (15.8%-38.6%). Interspinous vertebropexy significantly reduced ROM after unilateral facetectomy: in FE by 73% (p=.001), in LS by 23% (p=.001), in LB by 13% (p=.003), in AS by 16% (p=.007), and in AR by 20% (p=.001). In FE and LS the ROM was lower than in the baseline/native condition. In AS and AR, the baseline ROM was not reached by 17% and 1%, respectively. Spinolaminar vertebropexy significantly reduced ROM after unilateral facetectomy: in FE by 74% (p=.001), in LS by 24% (p=.001), in LB by 13% (p=.003), in AS by 28% (p=.004), and in AR by 15 % (p=.001). Baseline ROM was not reached by 9% in AR.

CONCLUSION

Interspinous vertebropexy seems to sufficiently counteract destabilization after unilateral total facetectomy, and limits range of motion in flexion and extension while avoiding full segmental immobilization. Spinolaminar vertebropexy additionally restores native anteroposterior stability, allowing satisfactory control of shear forces after facetectomy.

CLINICAL SIGNIFICANCE

Lumbar vertebropexy seems promising to counteract the destabilizating effect of facetectomy by targeted stabilization.

Transforaminal Endoscopic Lumbar Foraminotomy for Juxta-Fusional Foraminal Stenosis

Adjacent segment foraminal stenosis is a significant adverse event of lumbar fusion. Conventional revision surgery with an extended fusion segment may result in considerable surgical morbidity owing to extensive tissue injury. Transforaminal endoscopic lumbar foraminotomy (TELF) is a minimally invasive surgical approach for symptomatic foraminal stenosis. This study aimed to demonstrate the surgical technique and clinical outcomes of TELF for the treatment of juxta-fusional foraminal stenosis. Full-scale foraminal decompression was performed via a transforaminal endoscopic approach under local anesthesia. A total of 22 consecutive patients who had undergone TELF were evaluated. The included patients had unilateral foraminal stenosis at the juxta-fusional level of the previous fusion surgery, intractable lumbar radicular pain despite at least six months of non-operative treatment, and verified pain focus by imaging and selective nerve root block. The visual analog scale and Oswestry Disability Index scores significantly improved after the two-year follow-up period. The modified MacNab criteria were excellent in six patients (27.27%), good in 12 (55.55%), fair in two (9.09%), and poor in two (9.09%), with a 90.91% symptomatic improvement rate. No significant surgical complications were observed. The minimally invasive TELF is effective for juxta-fusional foraminal stenosis.

Full-endoscopic trans-pars interarticularis approach for far lateral lumbar discectomy

PURPOSE

Surgical management of far lateral disc herniations remains challenging. Current transforaminal full-endoscopic approaches require non-visualized docking in the Kambin's triangle and have been associated with significant risk of inadvertent nerve injury. We develop a full-endoscopic approach based on reliable bony landmarks allowing for visualization of the exiting nerve root prior to the far lateral discectomy.

METHODS

The surgical details of a full-endoscopic trans-pars interarticularis approach for far lateral discectomy are described. These descriptions include high quality intraoperative images and important surgical pearls. A small patient cohort is presented to demonstrate feasibility and safety of the procedure.

RESULTS

We demonstrate the feasibility of this approach in 14 patients with a mean age of 59.5 ± 14.7 years. At a mean follow up of 21.9 ± 6.8 months, improvement of the visual analogue scale (VAS) for leg pain was 4.3 ± 1.0 resulting in minimally clinically important difference in 78.6% of the patients. The mean improvement in VAS for the back pain was 2.6 ± 0.8 and for Oswestry disability index (ODI) was 20.6 ± 5.3. Nuances of the trans-pars surgical techniques are presented in a patient with a right-sided L4-5 far lateral disc herniation. Preoperative imaging studies, steps of the surgical progression, and intraoperative views are described in detail.

CONCLUSION

Using the pars interarticularis as the bony target area allows for safe visualized access to the extraforaminal compartment of the exiting nerve root. This novel surgical technique has the potential benefit of decreasing inadvertent neural injury and subsequent postoperative dysesthesias.

A transfacet approach to the lumbar nerve root canal: technical note

BACKGROUND

Intraforaminal and extraforaminal nerve root compressions caused by disk herniation or stenosis are relatively common causes of lumbar radiculopathy. Currently, the two available surgical treatment methods are decompression from the spinal canal or lateral decompression via the Wiltse approach.

OBJECTIVE

To describe a novel transosseous approach to the lumbar nerve root canal.

METHODS

Transfacet foraminotomy was performed in 11 patients with intraforaminal or extraforaminal disk herniation. The outcome was measured using the Patient Satisfaction Index (PSI), need for reoperation, radiographic criteria, and finite element analysis.

RESULTS

We noted that at the time of dismissal, PSI scores of 1 and 3 were reported by 10 and one patients, respectively. At the last follow-up, 10 patients reported a PSI score of 1 or 2. Two patients required reoperation because of recurrent disk herniation. Two patients underwent computed tomography (CT) postoperatively, which showed the transfacet approach. Intriguingly, a second postoperative CT after one month showed that the hole through the facet joint had shrunk significantly.

CONCLUSION

A posterior-anterior transfacet approach for intraforaminal or extraforaminal disk herniations using an ellipsoid facetectomy is safe and allows for fast and comfortable decompression of the nerve root without compromising the long-term strength of the facet joint.

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.

Surgical Treatment of Far Lateral Lumbar Disc Herniation: Outcomes of the Safe and Simple Midline Approach

Objective

Surgery for far lateral lumbar disc herniation (FLLDH) hernias is different than surgery for median and paramedian disc hernias. Our study offers a minimally invasive surgical technic for far lateral disc herniations.

Methods

The results of the midline surgical approach in 18 patients diagnosed with FLLDH were evaluated retrospectively.

Results

A total of 18 patients (7 females, 11 males), with a mean age of 57.9±9.4 years (range: 35-71 years), were included in the analyses. Three patients (16.7%) had lesions at the left L3-L4 level, six patients (33.3%) on the left L4-L5 level, five patients (27.8%) on the right L3-L4 level, and four patients (22.2%) on the right L4-L5 level. All patients had low back and leg pain. These complaints completely regressed after surgery.

Conclusion

This study presents a review of a consecutive series of patients who underwent minimally invasive surgery for FLLDH using a midline approach.

Extreme lateral and interlaminar approach for intra-canal and foraminal double disc herniation at lumbosacral level

INTRODUCTION AND OBJECTIVES

There are several approaches for double disc herniation consisting of an intracanal and foraminal lesion. Of several approaches, we introduced extreme lateral and interlaminar approach (ELIA). And we aimed to compare the approach with the conventional combined interlaminar and paraisthmic approach (CIPA).

PATIENTS AND METHODS

The authors reviewed the medical charts of patients who underwent a procedure for a double disc herniation at the lumbosacral level between March 2012 and February 2016 and patients who underwent CIPA or ELIA were selected. For preoperative testing, simple X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) scans were performed. For postoperative outcomes, the Korean version of the Oswestry Disability Index (K-ODI) and Numeric Rating Scale (NRS) at one, two, and three months post-operation were checked.

RESULTS

Eleven patients were given ELIA and twenty-four patients were involved in CIPA. The mean pre K-ODI was 34.1 (±13.9) and 32.4 (±4.0) at each group. 1st, 2nd and 3rd month post-operative K-ODI was 8.2 (±4.1), 6.4 (±2.1) and 5.3 (±2.4) in ELIA and 8.1 (±3.2), 7.1 (±3.5) and 8.4 (±6.4) in CIPA. Post-operative 3rd month K-ODI showed significant difference between two groups (p: 0.005). The mean pre NRS was 8 (±0.9) and 8.6 (±1.0). 1st, 2nd and 3rd month post-operative NRS was 2.4 (±1.5), 2.2 (±1.5) and 2.0 (±0.9) in ELIA and 3.3 (±1.4), 3.3 (±1.6) and 3.7 (±1.9). Post-operative 3rd month NRS showed significant difference between two groups as well (p: 0.001). There were four (19.0%) recurrence cases in CIPA patients group, otherwise there was no recurrence case in ELIA group.

CONCLUSIONS

In the treatment of L5-S1 double disc herniation, the ELIA surgical approach showed better outcomes than the CIPA surgical approach did with respect to pain and K-ODI during a mid-term follow-up examination conducted three months post-operation.

Facet Joints of the Spine: Structure–Function Relationships, Problems and Treatments, and the Potential for Regeneration

The zygapophysial joint, a diarthrodial joint commonly referred to as the facet joint, plays a pivotal role in back pain, a condition that has been a leading cause of global disability since 1990. Along with the intervertebral disc, the facet joint supports spinal motion and aids in spinal stability. Highly susceptible to early development of osteoarthritis, the facet is responsible for a significant amount of pain in the low-back, mid-back, and neck regions. Current noninvasive treatments cannot offer long-term pain relief, while invasive treatments can relieve pain but fail to preserve joint functionality. This review presents an overview of the facet in terms of its anatomy, functional properties, problems, and current management strategies. Furthermore, this review introduces the potential for regeneration of the facet and particular engineering strategies that could be employed as a long-term treatment.

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.

The Use of Tubular Retractors for Translaminar Discectomy for Cranially and Caudally Extruded Discs

BACKGROUND

The conventional interlaminar approach is adequate for access to most disc herniations in lumbar spine surgery. The access to cranially and caudally migrated disc fragments, by conventional interlaminar fenestration, requires an extension of the fenestration with the potential destruction of the facet joint complex and consequent postsurgical instability. To describe the technique and results of the translaminar technique of targeted discectomy using tubular retractors for the surgical treatment of cranially and caudally extruded discs.

MATERIALS AND METHODS

The study period extended from January 2008 to December 2014. All patients with lumbar herniated discs who failed conservative management were selected for surgery and underwent routine erect radiographs and magnetic resonance imaging (MRI) of the lumbar spine. The patients with cranially or caudally migrated discs were included in this study. The technique involves approaching migrated disc through an oval window (sculpted through an 18 mm tubular retractor using a burr) in the lamina precisely over the location of the migrated disc as predicted by the preoperative MRI (inferior lamina for inferior migration and superior lamina for superior migration). The perioperative parameters studied were operative time, blood loss, complications, Oswestry Disability Index (ODI), and visual analog scale (VAS) for leg pain before surgery and at last followup. In the study, 4 patients underwent a postoperative computed tomography-scan with a three-dimensional reconstruction to visualize the oval window and to rule out any pars fracture. All technical difficulties and complications were analyzed.

RESULTS

17 patients in the age group of 41-58 years underwent the translaminar technique of targeted discectomy. The migration of disc was cranial in 12 patients and caudal in 5 patients. Fourteen of the affected discs were at the L4-L5 level and three were at the L5-S1 level. The mean VAS (leg pain) scale improved from 8 to 1 and the mean ODI changed from 59.8 to 23.6. There were no intraoperative or postoperative complications encountered in this study. Furthermore, no patient in the present study required a conventional laminotomy or medial facetectomy. There was no evidence of iatrogenic pars injury or instability at the last followup. There were no recurrences till the last followup.

CONCLUSIONS

The targeted translaminar approach preserves structures important for segmental spinal stability thus causing minimal anatomical disruption. This approach allows access to the extruded disc fragment and intervertebral disc space comparable to classical approaches.

Radiographic Assessment on Magnetic Resonance Imaging after Percutaneous Endoscopic Lumbar Foraminotomy

Percutaneous endoscopic lumbar foraminotomy (ELF) is a novel minimally invasive technique used to treat lumbar foraminal stenosis. However, the validity of foraminal decompression based on quantitative assessment using magnetic resonance imaging (MRI) has not yet been established. The objective of this study was to investigate the radiographic efficiency of ELF using MRI. Radiographic changes of neuroforamen were measured based on pre- and postoperative MRI findings. Images were blindly analyzed by two observers for foraminal stenosis grade and foraminal dimensions. The intraclass correlation coefficient (ICC) and k statistic were calculated to determine interobserver agreement. Thirty-five patients with 40 neuroforamen were evaluated. The mean visual analog scale (VAS) score improved from 8.4 to 2.1, and the mean Oswestry disability index (ODI) improved from 65.9 to 19.2. Overall, 91.4% of the patients achieved good or excellent outcomes. The mean grade of foraminal stenosis significantly improved from 2.63 to 0.68. There were significant increases in the mean foraminal area (FA) from 50.05 to 92.03 mm², in mean foraminal height (FH) from 11.36 to 13.47 mm, in mean superior foraminal width (SFW) from 6.43 to 9.27 mm, and in mean middle foraminal width (MFW) from 1.47 to 78 mm (P < 0.001). Interobserver agreements for preoperative and postoperative measurements were good to excellent with the exception of SFW. In conclusion, foraminal dimensions and grades of foraminal stenosis significantly improved after ELF. These findings may enhance the clinical relevance of endoscopic lumbar foraminal decompression.

Surgical treatment of intraforaminal/extraforaminal lumbar disc herniations: Many approaches for few surgical routes

BACKGROUND

Several disc disease nomenclatures and approaches for LDH exist. The traditional midline bone-destructive procedures together with approaches requiring extreme muscular retraction are being replaced by muscle sparing, targeted, stability-preserving surgical routes. The increasing speculation on LDHs and the innovative corridors described to treat them have lead to an extensive production of papers frequently treating the same topic but adopting different terminologies and reporting contradictory results.

METHODS

The review of such literature somehow confounding gave us the chance to regroup by surgical corridors the vast amount of approaches for LDH differently renamed over time. Likewise, LDHs were simplified in intra-foraminal (ILDH), extra-foraminal (ELDH), and intra-/extra-foraminal (IELDH) in relation to precise anatomical boundaries and extent of bulging disc.

RESULTS

Through the analysis of the papers, it was possible to identify ideal surgical corridors for ILDHs, ELDHs, and IELDHs, distinguishing for each approach the exposure provided and the technical advantages/disadvantages in terms of muscle trauma, biomechanical stability, and nerve root preservation. A significant disproportion was noted between studies discussing traditional midline approaches or variants of the posterolateral route and those investigating pros and cons of simple or combined alternative corridors. Although rarely discussed, these latter represent valuable strategies particularly for the challenging IELDHs, thanks to the optimal compromise between herniation exposure and bone-muscle preservation.

CONCLUSIONS

The integration of adequate mastery of traditional approaches together with a greater confidence through unfamiliar surgical corridors can improve the development of combined mini-invasive procedures, which seem promising for future targeted LDH excisions.

Clinical and radiological outcomes of endoscopic partial facetectomy for degenerative lumbar foraminal stenosis

BACKGROUND

Several different techniques exist to treat degenerative lumbar foraminal stenosis. Failure to adequately decompress the lumbar foramen may lead to failed back surgery syndrome. However, wide decompression often causes spinal instabilities or may require an additional fusion surgery. The aim of this study was to report the outcomes of endoscopic partial facetectomy (EPF) performed on patients with degenerative lumbar foraminal stenosis.

METHODS

Between 2012 and 2014, 25 consecutive patients (12 women and 13 men) who underwent EPF were included in the study. The patients were assessed before surgery and followed-up regularly during outpatient visits (preoperatively and 1, 3, 6, 12, and 24 months postoperatively). The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) outcome questionnaire. The radiological outcome was measured using the lumbar Cobb angle, disc wedging angle, lumbar lordosis (LL), slip percentage, and disc height index (DHI) in plain standing radiographs.

RESULTS

The VAS, ODI, and SF-36 scores significantly improved at 1 month of follow-up compared with the baseline mean values and were maintained within the 2-year follow-up period. There was no radiologic progression in the lumbar Cobb's angle, disc wedging angle, LL, slip percentage, and DHI between preoperatively and 2 years postoperatively. In addition, the EPF with discectomy group and the EPF group were not significantly different in terms of clinical and radiological outcomes.

CONCLUSIONS

EPF is an effective option in decompressing the lumbar exiting nerve root without causing spinal instabilities for the treatment of patients with lumbar foraminal stenosis.

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.

Direct Tubular Lumbar Microdiscectomy for Far Lateral Disc Herniation: A Modified Approach

OBJECTIVE

The concept of minimally invasive tubular discectomy is based on precise placement of the retractor over the surgical target to minimize collateral tissue trauma. For far lateral disc herniation, the junction between the pars and the transverse process has generally been adopted as the target for facilitating early nerve root exposure; however, this may limit access to the disc space and increase the risks of iatrogenic neuralgia. An alternative approach to help address these issues involving docking the retractor caudally directly over the disc space with the aid of a microscope is here proposed. The purpose of this study was to evaluate the safety and efficacy of such an approach.

METHODS

Nineteen patients in whom the modified approach was performed over a 35-month period were identified. Direct access to the disc space was attained by directing the retractor against the lateral margin of the facet joint and following the inferior transverse process medially towards the foramen with minimal exposure of the nerve root. Clinical outcomes were assessed by the Oswestry Disability Index, visual analogue scale scores for leg and back pain, Short Form 36 physical functioning (SF36-PF) and bodily pain (SF36-BP) scores and sciatica bothersomeness and frequency indexes (SBI & SFI) and obtained from a prospective patient database. Follow-up data in the first 6 months were compared with preoperative baseline data.

RESULTS

All procedures were successfully completed with the modified approach. Contained disc herniation without sequestrated fragments was found in all but four cases. No perioperative complications or reoperation were recorded and no postoperative dysesthesia was noted. Clinically significant reductions in mean Oswestry Disability Index (32; 95% CI, 21-43) and visual analogue scale scores for leg pain (38 mm; 95% CI, 23-54 mm) and back pain (35 mm; 95% CI, 21-48 mm) scores were noted in the first 6 months. Significant improvements in SF36-PF (40; 95% CI, 30-51) and SF36-BP (35; 95% CI, 26-43), SBI (9; 95% CI, 6-11) and SFI (11; 95% CI, 8-13) were also recorded.

CONCLUSIONS

A modified direct tubular approach is safe and effective for treating far lateral lumbar disc herniation. Our early results suggest that this approach helps safeguard adequate decompression and reduce the risk of postoperative dysesthesia.

Transpars Microscopic Approach for the Treatment of Purely Foraminal Herniated Lumbar Disc: A Clinical, Radiological, Two-center Study

STUDY DESIGN

This is a prospective two-center study.

OBJECTIVE

The aim of this study was to assess the safety and efficacy of treating patients with lumbar foraminal disc herniations via a microscopic transpars approach, with a clinical and radiological follow-up evaluation.

SUMMARY OF BACKGROUND DATA

Purely foraminal lumbar disc herniations comprise about 5% of all lumbar herniated intervertebral discs. Operative management can be technically difficult, and the optimum surgical treatment remains controversial.

METHODS

From January 2012 to January 2015, 47 patients were prospectively recruited. Patients were followed-up as outpatients at 1 week after discharge, then at 1, 6, and 12 months.A clinical multiparametric evaluation of patients including numeric rating scale (NRS), drugs intake, Macnab criteria, and working days lost was used.Postoperative dynamic x-rays (flexion, extension) were performed in all cases 12 months after surgery.

RESULTS

No surgery-related complications occurred.Among the 35 patients who were not retired at the time of the study, 29 patients returned to work and to normal daily activities within 60 days after surgery.Pain evaluation at discharge showed a significant improvement of NRS score, from 8.93 to 1.45 at 12 months. Root palsy significantly improved in all cases already at 1-month follow-up. Drugs intake analysis showed that at 6-month follow-up, no patients used steroids, or opioids, 17 patients used non-steroidal anti-inflammatory drugs when needed, and 29 patients (61.7%) used no drugs for pain relief. No significant variations occurred at 12-month-follow-up.At 12-month follow-up, excellent or good outcome (following Macnab criteria) was achieved in 36 (76.6%) and 8 (17%) patients, respectively.There were no cases of spinal instability at 12-month radiological evaluation.No recurrence occurred at follow-up.

CONCLUSION

Transpars microscopic approach is effective and safe for the treatment of FLDH, but larger studies are needed.

LEVEL OF EVIDENCE

3.

Extraforaminal Disk Herniation Treatment with Surgical Exploration by Unilateral Intertransversarii Microsurgical Approach

BACKGROUND

In this study we evaluated the role of a unilateral intertransversarii microsurgical approach for the treatment of extraforaminal lumbar disk herniations (ELDHs), with short-, medium-, and long-term follow-up.

METHODS

We retrospectively evaluated 96 patients who had undergone surgery for ELDH between 2001 and 2012 at our Institution. All the patients had been examined before the intervention, immediately after, and at 6 weeks, 6 months, and 18 months after the intervention. All the patients underwent surgical exploration with a unilateral intertransversarii microsurgical approach. After a midline incision was made, the paraspinal muscles were retracted laterally up to the transverse process, in order to visualize the intertransversarii ligament. Removal of this ligament allows microsurgical exposure of the extraforaminal pathology. If necessary, interlaminar microsurgical exploration is performed in the same session.

RESULTS

At 6-week postoperative follow-up we noted a significant decrease of pain both in patients who suffered from leg pain and in patients who reported back pain. Also, sensory and motor deficits had improved considerably. At 6-month postoperative follow-up we observed a further improvement in the clinical conditions of almost all patients. At the 18-month postoperative follow-up we observed a very low incidence of relapse of neurological symptoms.

CONCLUSION

Our technique can be reasonably proposed because of its low morbidity, fast recovery, and short hospital stay.

Technical note: microdiscectomy and translaminar approach

Lumbar disk herniation (LDH) is a degenerative pathology. Although LDH generally occurs without migration of the fragment to the levels above or below, in 10% of the cases, this circumstance might happen. In these cases, the standard interlaminar approach, described by Caspar cannot be performed without laminotomies, interlaminectomies, or partial or total facetectomies. The translaminar approach is the only "tissue-sparing" technique viable in cases of cranially migrated LDH encroaching on the exiting nerve root in the preforaminal zones, for the levels above L2-L3, and in the preforaminal and foraminal zones, for the levels below L3-L4 (L5-S1 included, if a total microdiscectomy is unnecessary). This approach is more effective than the standard one, because it resolves the symptoms; it is associated with less postoperative pain and faster recovery times without the risk of iatrogenic instability, and it can also be used in cases with previous signs of radiographic instability. The possibility to spare the flavum ligament is one of the main advantages of this technique. For these reasons, the translaminar approach is a valid technique in terms of safety and efficacy. In this article the surgical technique will be extensively analyzed and the tips and tricks will be highlighted.

Navigated Transtubular Extraforaminal Decompression of the L5 Nerve Root at the Lumbosacral Junction: Clinical Data, Radiographic Features, and Outcome Analysis

Purpose. Extraforaminal decompression of the L5 nerve root remains a challenge due to anatomic constraints, severe level-degeneration, and variable anatomy. The purpose of this study is to introduce the use of navigation for transmuscular transtubular decompression at the L5/S1 level and report on radiological features and clinical outcome. Methods. Ten patients who underwent a navigation-assisted extraforaminal decompression of the L5 nerve root were retrospectively analyzed. Results. Six patients had an extraforaminal herniated disc and four had a foraminal stenosis. The distance between the L5 transverse process and the para-articular notch of the sacrum was 12.1 mm in patients with a herniated disc and 8.1 mm in those with a foraminal stenosis. One patient had an early recurrence and another developed dysesthesia that resolved after 3 months. There was a significant improvement from preoperative to postoperative NRS with the results being sustainable at follow-up. ODI was also significantly improved after surgery. According to the Macnab grading scale, excellent or good outcomes were obtained in 8 patients and fair ones in 2. Conclusions. The navigated transmuscular transtubular approach to the lumbosacral junction allows for optimal placement of the retractor and excellent orientation particularly for foraminal stenosis or in cases of complex anatomy.

Combined Interlaminar and Paraisthmic Approach for Co-existing Intracanal and Foraminal Lesion

Objective

Stenosis or herniated nucleus pulposus (HNP) occupying lumbar intracanal and foraminal area is an important cause of double radicular symptoms. Using the combined interlaminar and paraisthmic approach, we performed decompression surgery in patients with co-existing intracanal and foraminal lesions. The objective of this study is to describe usefulness and outcome of combined interlaminar and paraisthmic approach surgery and to analysis the cause of poor outcome.

Methods

Between Apr 2009 and Apr 2014, 78 patients (42 males and 36 females) with intracanal and foraminal lesions were enrolled in this study. Patients with a vacuum disc, spondylolisthesis, instability or an isthmic defect on the preoperative dynamic view radiograph were excluded from this study. All patients underwent surgery through a combined approach for discectomy and decompression. The outcome of surgery was evaluated and classified into excellent, good, fair and poor.

Results

The results were excellent in 53 patients, good in 9, fair in 6 and poor in 10 during the follow-up. The outcome of the combined approach was excellent to fair in 87% (68 of 78) patients in our study. In the poor outcome group, three patients complained of early-onset relapsed pain (<1 month) and another seven patients complained of delayed-onset pain (>3 months).

Conclusion

Combined approach for both intracanal and foraminal area lesions may be useful if selectively performed on patients whose facet joint is relatively intact, and that it is worthy of consideration as an alternative to fusion surgery; however, further studies are needed.

A Modified Approach of Percutaneous Endoscopic Lumbar Discectomy (PELD) for Far Lateral Disc Herniation at L5-S1 with Foot Drop

Foraminal or extraforaminal Far Lateral Disc Herniations (FLDH) extending into or beyond the foraminal zone have been recognized as between 7-12% of all lumbosacral disc herniations. Conventional posterior laminectomy may not provide good access to a herniation that lies far lateral to the lateral margin of the pedicle. Use of the endoscopic technique through a percutaneous approach to treat such FLDH patients can decrease the surgical morbidity while achieving better outcomes. We made an effort to utilize the advantages of percutaneous endoscopic lumbar discectomy (PELD) and to determine the appropriate approach for FLDH at the level between the 5th Lumbar and first Sacral vertebrae(L5-S1). The authors present a case of an endoscopically resected lumbar extruded disc of the left extraforaminal zone with superior foraminal migration at the level of L5-S1, which had led to foot drop, while placing the endoscope in the anterior epidural space without facetectomy.

Microdiskectomy and translaminar approach: minimal invasiveness and flavum ligament preservation

Study Design Retrospective study. Objective The interlaminar approach represents the standard procedure for the surgical treatment of lumbar disk herniation (LDH). In the case of disk herniations in the "hidden zone," it could be necessary to perform laminotomies or laminectomies and partial or total facetectomies to remove the herniated fragment, thus leading to iatrogenic instability. The objective of the study is to evaluate the translaminar approach, in terms of the results, safety, and efficacy compared with the standard approach. Methods Since February 2010, 38 patients (26 men and 12 women; mean age 50.9 years, range 31 to 78 years) with LDH and migration into the hidden zone underwent a microdiskectomy by the translaminar approach. Using a micro-diamond dust-coated burr, a translaminar hole (8 ± 2 mm) was made, with subsequent exposure of the involved root and removal of the fragment. A clinical follow-up was performed at months 1, 3, 6, and 12 using the visual analog scale and the Oswestry Disability Index. All patients were evaluated according to the Spangfort score. Postoperative radiographic evaluations were done at 1, 6, and 12 months (dynamic radiographic studies done at 6 and 12 months). Results In over 60% of cases, L4-L5 was the involved disk. The visualization of the roots was successfully achieved through a translaminar approach. No laminotomies, laminectomies, or partial or total facetectomies were performed. The flavum ligament was always spared. A severe intraoperative bleeding episode occurred in 5% of the cases, due to involvement of the epidural veins, but it did not result in prolonged operative time (mean duration 60 ± 10 minutes). The patients showed a gradual resolution of the back pain and a progressive resolution of the radicular pain and the neurologic deficits. No sign of radiographic instability was documented during the follow-up. No infections, dural tears, or spinal cord injuries occurred. No revision surgery was performed. Conclusion The translaminar approach is the only tissue-sparing technique viable in case of cranially migrated LDH encroaching on the exiting nerve root in the preforaminal zones, for the levels above L2-L3, and in the preforaminal and foraminal zones, for the levels below L3-L4 (L5-S1 included, if a total microdiskectomy is not necessary). The possibility to spare the flavum ligament is one of the main advantages of this technique. According to our experience, the translaminar approach is an effective and safe alternative minimally invasive surgical option.

Percutaneous endoscopic lumbar foraminotomy: an advanced surgical technique and clinical outcomes

Supplemental Digital Content is Available in the Text.

BACKGROUND:

Although several authors have reported the use of endoscopic techniques to treat lumbar foraminal stenosis, the practical application of these techniques has been limited to soft disc herniation.

OBJECTIVE:

To describe the details of the percutaneous endoscopic lumbar foraminotomy (ELF) technique for bony foraminal stenosis and to demonstrate the clinical outcomes.

METHODS:

Two years of prospective data were collected from 33 consecutive patients with lumbar foraminal stenosis who underwent ELF. The surgical outcomes were assessed using the visual analog scale, Oswestry Disability Index, and modified MacNab criteria. The procedure begins at the safer extraforaminal zone rather than the riskier intraforaminal zone. Then, a full-scale foraminal decompression can be performed using a burr and punches under endoscopic control.

RESULTS:

The mean age of the 18 female and 15 male patients was 64.2 years. The mean visual analog scale score for leg pain improved from 8.36 at baseline to 3.36 at 6 weeks, 2.03 at 1 year, and 1.97 at 2 years post-surgery (P < .001). The mean Oswestry Disability Index improved from 65.8 at baseline to 31.6 at 6 weeks, 19.7 at 1 year, and 19.3 at 2 years post-surgery (P < .001). Based on the modified MacNab criteria, excellent or good results were obtained in 81.8% of the patients, and symptomatic improvements were obtained in 93.9%.

CONCLUSION:

Percutaneous ELF under local anesthesia could be an efficacious surgical procedure for the treatment of foraminal stenosis. This procedure may offer safe and reproducible results, especially for elderly or medically compromised patients.

ABBREVIATIONS:

ELF,endoscopic lumbar foraminotomy

ODI, Oswestry Disability Index

VAS, visual analog scale

Early postoperative results after removal of cranially migrated lumbar disc prolapse: retrospective comparison of three different surgical strategies

Background. To compare the early postoperative results of three surgical approaches to lumbar disc herniations that migrated cranially. Minimally invasive techniques such as the translaminar and endoscopic transforaminal approaches are utilized in patients with lumbar disc herniations to gain access to cranially located disc material and to avoid the potentially destabilizing resection of ligament and bone tissue, which is associated with an extended interlaminar approach. Methods. This retrospective study compares the postoperative pain and functional capacity levels of 69 patients who underwent an interlaminar (Group A, n = 27), a translaminar (Group B, n = 22), or an endoscopic transforaminal procedure (Group C, n = 20). Results. Median VAS scores for leg pain decreased significantly from before to after surgery in all groups. Surgical revisions were required in thirteen cases (five in Group A, one in Group B, and seven in Group C; P = 0.031). After six weeks, there were significant differences in back pain and functional outcome scores and in the results for the MacNab criteria but not in leg pain scores. Conclusions. The interlaminar and translaminar techniques were the safest and fastest ways of gaining access to cranially migrated disc material and the most effective approaches over a period of six weeks.

Transtubular microsurgical approach to treating extraforaminal lumbar disc herniations

OBJECT

Approaches to treating extraforaminal lumbar disc herniations can be challenging due to the unique anatomy and the need to prevent spinal instability. Numerous approaches, including conventional midline, paramedian, minimally invasive, and full endoscopic approaches, have been described. The purposes of this study were to point out the outcome and clinical advantages of a transtubular microsurgical approach and to describe and illustrate this technique.

METHODS

Between 2009 and 2012, a series of 51 patients underwent a minimally invasive dilative transtubular microsurgical approach for the treatment of extraforaminal lumbar disc herniations. All patients were clinically evaluated using the visual analog scale (VAS) and Oswestry Disability Index preoperatively and 6 months postoperatively.

RESULTS

Both pain scores and functional status showed significant improvement after surgery (p < 0.001): radicular pain decreased from VAS score of 7.9 to one of 1.3, lower back pain from VAS score of 2.4 to 1.4, and the Oswestry Disability Index from 42.0 to 12.3. Subgroup analyses revealed no differences in outcome regarding obesity or timing of surgery (early vs late intervention). Highly significant was the correlation between preoperative radicular pain activity and timing of surgical intervention (p < 0.001).

CONCLUSIONS

The dilative transtubular microsurgical approach combines the advantages of the conventional open muscle-splitting approach and the endoscopic approach. The technique is easy to use with a steep learning curve. Less muscle trauma and the absence of bony resection prevent facet pain and instability, thereby contributing to a rapid recovery. Patients in this series improved excellently in the short-term follow-up.

Percutaneous endoscopic treatment of foraminal and extraforaminal disc herniation at the L5-S1 level

BACKGROUND

Microsurgery of foraminal and extraforaminal disc herniation at the L5-S1 level remains a challenge because of the limited access by a high iliac crest, the sacral ala, large transverse processes of L5 and hidden disc fragments lateral to the zygapophyseal joint. Our aim was to present the outcome of percutaneous endoscopic lumbar discectomy (PELD) of these lateral and far lateral disc herniations at the L5-S1 level using the newly described foraminal retreat technique in a group of patients with similar preoperative diagnostic studies.

METHODS

A total of 22 patients, 13 males and 9 females, with foraminal and extraforaminal lumbar disc herniation at the L5-S1 level were treated by applying the PELD between September 2004 and April 2010. The clinical findings and MRI were the main diagnostic methods. Preoperative evaluation was performed with clinical examinations, the Visual Analog Pain Scale (VAS) and Oswestry Low Back Disability Index (ODI).

FINDINGS

According to the Macnab criteria, overall excellent or good outcomes were obtained in 18 patients (81.8 %), fair outcomes in 3 patients (13.6 %) and a poor outcome in 1 patient (4.5 %) at the last follow-up. The mean ODI was 67.3 ± 19.4 preoperatively and 26.7 ± 23.4 postoperatively. Preoperative VAS was 88.6 ± 7.6 and 28.6 ± 22.8 at 2 days, 40.5 ± 22.8 at 3 weeks, 34.3 ± 25.1 at 6-months and 32 at the last follow-up. At follow-up, two patients (9.1 %) had recurrent disc herniations that were corrected with open surgery. At the time of surgery, 16 patients held jobs. Fifteen (15) patients (93.8 %) returned to their original jobs postoperatively; one patient could not return to his original job postoperatively because of a comorbidity.

CONCLUSIONS

Percutaneous endoscopic discectomy using the foraminal retreat technique is an effective treatment method for patients with foraminal and extraforaminal disc herniations at the L5-S1 level on appropriately selected patients.

Translaminar approach to cranio-laterally herniated lumbar disc prolapse

BACKGROUND

For cranio-laterally extruded disc fragments, a far enlargement of the standard interlaminar fenestration is necessary. This strategy harbours a potential risk for relevant destruction of the facet joints and postsurgical instability could be the consequence. For preserving the facet joint, a limited approach through the hemilamina is possible.

METHOD

After the standard paramedian soft tissue approach and retraction of the paravertebral muscles laterally, the hemilamina is exposed and fenestrated, preserving the bony borders of the lamina. The disc herniation can be extracted via this lamina fenestration.

CONCLUSION

This surgical strategy is safe and effective in approaching cranially herniated disc fragments.

Ultra-long-term outcome of surgically treated far-lateral, extraforaminal lumbar disc herniations: a single-center series

PURPOSE

Far-lateral extraforaminal lumbar disc herniation is an uncommon cause of nerve root entrapment, and studies addressing the long-term outcome of surgically treated patients are few. The purpose of this study was to analyze the ultra-long-term outcome of patients who were treated via a lateral approach.

METHODS

The medical reports of 138 consecutive patients were analyzed with regard to signs and symptoms, operative findings, complications, and short-term outcome (6 weeks). To assess long-term results, standardized telephone interviews were performed using a structured questionnaire. The patients were questioned about pain using the verbal rating scale and persisting symptoms, if any. Other queries were related to the Oswestry Disability Index. Subjective satisfaction with the result of surgery was classified as excellent (no pain), good (some pain), fair (moderate pain), and poor (unchanged or worse) based on MacNab classification.

RESULTS

At short-term follow-up, major and moderate leg pain had decreased from 99.3 to 5.1% and low back pain from 97.8 to 2.8%. Sensory and motor deficits, however, were still present in the majority of patients. A total of 87 telephone interviews were conducted, and the mean follow-up was 146 months. As many as 49 patients (56.3%) reported complete relief of symptoms, 14 patients (16.1%) had minor ailments under physical stress, and 24 patients (27.6%) had permanent residual symptoms. The most common complaint was remaining sensory disturbance. Despite residual symptoms, the vast majority of patients expressed satisfaction with the result of surgery. The outcome was subjectively rated as follows: 75.9% excellent (66 patients), 18.4% good (16 patients), 4.6% fair (4 patients), and 1.1% poor (1 patient).

CONCLUSIONS

The lateral approach is a minimally invasive and safe procedure with low complication rates. The profit from surgery is maintained beyond the usual postoperative observation periods. Thus, ultimate outcome at ultra-long-term follow-up is very gratifying in the vast majority of patients.

Minimally invasive approach to far lateral lumbar disc herniation: technique and clinical results

BACKGROUND

To describe our minimally invasive technique for the surgical treatment of far lateral lumbar disc herniation (FLLDH) using MetRx tissue dilators system and a surgical microscope; and to report our experience with this method.

METHODS

Retrospective analysis of data of all patients with FLLDH treated by minimally invasive discectomy. Outcome assessment was performed using neurological status, the visual analog scale (VAS) for back pain and leg pain, and the Short Form-36 Health Survey Questionaire (SF-36).

RESULTS

Thirty-one patients were included in this study. The mean follow-up time was 25.16 months. Muscle weakness improved in all patients. Sensory deficits disappeared in 22 patients and improved in the other five patients. The mean VAS for radicular pain showed significant improvement from 8.6 preoperatively, to 3.8 in the immediate postoperative period (P-value <.01), and 0.6 at the last follow-up. The mean VAS for back pain also showed significant improvement from 5.8 preoperatively, to 4.8 in the immediate postoperative period and 0.7 at the last follow-up visit. The SF 36 data showed significant improvement in all the eight domains: the physical functioning improved from 9.68 preoperatively to 76.33 at 6-month follow-up and SF 36 bodily pain index improved from 6.71 before surgery to 79.53 at 6-month follow up. Complications included two cases of incidental dural tear, without postoperative CSF leakage and one case of residual sequestered disc that was successfully removed by a second minimally invasive procedure.

CONCLUSION

Our results suggest that this minimally invasive technique is safe and efficacious for the management of FLLDH and might be an alternative to open microsurgical approaches.

Estudo da estabilidade da coluna lombar após facetectomia

OBJETIVO: determinar a presença, ou não, de instabilidade lombar após a realização de facetectomia total unilateral para a descompressão radicular. MÉTODOS: os autores realizaram uma análise retrospectiva por avaliação clínica e radiográfica de 29 pacientes operadores, por discopatia, durante o período de janeiro de 1985 até janeiro de 1995. Os pacientes apresentavam queixa de dor ciática aguda, sem dor lombar prévia, e foram submetidos à facetectomia total unilateral para a descompressão radicular. Os casos operados por esta técnica necessitaram de manipulações excessivas com riscos de lesão da raiz nervosa. RESULTADOS: após um seguimento que variou de 9 a 17 anos, os resultados foram excelentes em 17 pacientes, bom em 9, regular em 3. CONCLUSÃO: nessa série de casos, a facetectomia total unilateral não foi fator determinante de instabilidade lombar.

Minimally invasive approach to extraforaminal disc herniations at the lumbosacral junction using an operating microscope: case series and review of the literature

Surgical access to extraforaminal lumbar disc herniations is complicated due to the unique anatomical constraints of the region. Minimizing complications during microdiscectomies at the level of L5–S1 in particular remains a challenge. The authors report on a small series of patients and provide a video presentation of a minimally invasive approach to L5–S1 extraforaminal lumbar disc herniations utilizing a tubular retractor with microscopic visualization.

A minimally invasive technique for L5–S1 intraforaminal disc herniations: microdiscectomy with a tubular retractor via a contralateral approach

✓ Surgical treatment of intraforaminal disc herniations at the L5–S1 level is technically demanding. The 2 most commonly used procedures involve either a medial or lateral ipsilateral approach and often require a partial or even complete facet resection, which may in turn result in vertebral instability and/or back pain, as well as, in some cases, a fusion or stabilization procedure. In this report, the authors present a new minimally invasive technique for the treatment of L5–S1 intraforaminal disc herniations. Using this technique, which involves tubular retractors and an operative microscope to approach the neural foramen from the contralateral side, the authors could easily visualize and remove the herniated disc material and perform a thorough microdiscectomy with minimal resection of osseous and ligamentous structures. To illustrate this new minimally invasive technique for the treatment of intraforaminal disc herniations at L5–S1, they describe the cases of 2 patients who underwent the procedure and in whom successful results were achieved.

Avaliação da relação entre parâmetros antropométricos (peso e altura) e a topografia da raiz de L4 no espaço intertransversário L4-L5 através do acesso paramediano à coluna vertebral- Um estudo anatômico em vinte e um cadáveres

As hérnias discais extremolaterais correspondem a 10% das hérnias discais sintomáticas, mais comumente localizadas nos níveis L3-L4 e L4-L5. Por muitos anos, a abordagem cirúrgica das hérnias lombares foraminais e extraforaminais foi feita através de via de acesso posterior mediana com hemilaminectomia e facetectomia total ou parcial. A abordagem cirúrgica dessa patologia pela via paramediana, entre os músculos multífido e longuíssimo (via de Wiltse), tem a vantagem de poupar o paciente de perdas ósseas e permitir uma visão mais oblíqua do neuro-foramen. Essa abordagem permite, com mínima mobilização da raiz de L4, acesso ao disco L4-L5 e eventuais herniações extra-foraminais do mesmo. Nosso objetivo é avaliar se há relação entre características antropométricas de um indivíduo e a localização da raiz de L4 no espaço intertransversário, acessado pela via de Wiltse, para com isso poder antecipar alguns riscos cirúrgicos. Foram realizadas dissecções em 21 cadáveres (42 lados) e obtidas as respectivas medidas de peso e altura além da distância entre a base do processo transverso de L5 e o ponto onde a raiz de L4 o cruza. A análise dos dados nos permite concluir que não há relação estatisticamente significativa entre as variáveis envolvidas.

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.

Effects of Unilateral Endoscopic Facetectomy on Spinal Stability

There are various definitions for spinal instability and its exact clinical usefulness is uncertain. Facetectomy has been considered a potential source of instability via conventional approaches. Studies have suggested that if the ligament structure of the spine is maintained then instability may not occur with an endoscopic facetectomy. This study is a prospective analysis of 10 patients who underwent unilateral endoscopic facetectomy for the treatment of severe foraminal stenosis to determine whether endoscopic facetectomies result in instability. The patients underwent pre and postsurgical x-rays that were evaluated via a specialized computer program that determined whether or not there was any altered mobility between the 2 sets of x-rays. These were compared with controls to determine whether instability was present. Of the 10 endoscopic facetectomy patients, none had any statistically significant change in sagittal rotational or translational motion when compared to controls. Thus, endoscopic removal of a unilateral facet joint does not necessarily cause spinal instability possibly because of the reduction in tissue damage associated with an endoscopic approach and the maintenance of the ligament structure of the spine.

Translaminar microsurgical approach for lumbar herniated nucleus pulposus (HNP) in the "hidden zone": clinical and radiologic results in a series of 24 patients

STUDY DESIGN

Clinical series.

OBJECTIVE

To describe an alternative surgical approach for disc herniations in the "hidden zone."

SUMMARY OF BACKGROUND DATA

Many spine surgeons have suggested different surgical approaches for symptomatic preforaminal and foraminal disc herniations. However, almost every surgical approach has certain shortcomings when it comes to exposing the "hidden zone" without causing some degree of spinal instability.

METHODS

Twenty-four patients with preforaminal and foraminal disc herniation underwent surgical treatment via a translaminar microsurgical approach. RESULTS.: Excellent results were obtained in all patients in terms of pain relief, and all had improvement in motor strength except for 1 patient. No spinal instability was seen at the latest follow-up.

CONCLUSIONS

A classic interlaminar interspace approach combined with a very limited translaminar fenestration seem to be an acceptable surgical method for accessing a preforaminal disc herniation, and this technique has proven to be safe and did not cause any instability at the latest follow-up.

Percutaneous endoscopic discectomy for extraforaminal lumbar disc herniations: extraforaminal targeted fragmentectomy technique using working channel endoscope

STUDY DESIGN

A retrospective analysis of 41 patients operated for excision of soft lumbar extraforaminal disc herniation (EFDH) by percutaneous endoscopic extraforaminal approach under local anesthesia by a new technique.

OBJECTIVES

To describe a new and safer percutaneous endoscopic technique for the removal of soft EFDH and report the results on the basis of a new objective criterion modified from Oswestry Disability Index (ODI).

SUMMARY OF BACKGROUND DATA

EFDHs usually occur in older patients and present with atypical symptoms. Their diagnosis and treatment are still controversial, with various authors describing open midline or paraspinal approaches using the microscope with varying amounts of success. Percutaneous endoscopic techniques have traditionally been considered unsuitable for these herniations.

METHODS

Forty-one patients with a soft EFDH were subjected to percutaneous endoscopic discectomy with the new technique. In our technique, the skin entry point is medial and the angle of approach steeper as compared with the earlier described endoscopic techniques. This might help in avoiding exiting root injury and increasing the efficacy of the procedure. The results were analyzed on the basis of percentage change in ODI as compared with preoperative values.

RESULTS

Mean follow-up was 34.1 month. Mean VAS score for radicular pain improved from 8.6 to 1.9, and mean ODI improved from 66.3 to 11.5. Overall, 92% of patients experienced satisfactory outcome. Two patients had poor outcome due to the need for subsequent open surgery.

CONCLUSION

Percutaneous endoscopic discectomy using the "extraforaminal targeted fragmentectomy" technique is an effective and safe procedure for the select group of patients with a soft EFDH.

Transforaminal Percutaneous Endoscopic Discectomy in the Treatment of Foraminal and Extraforaminal Lumbar Disc Herniations

The objective of this study is to evaluate the efficacy of the endoscopic technique, as applied to patients with foraminal and extraforaminal disc herniations, and to report the outcome and complications. A retrospective analysis was performed of 35 consecutive cases of foraminal and extraforaminal lumbar disc herniation managed by posterolateral endoscopic discectomy. Pain was measured by means of the Visual Analog Score. Patient satisfaction was evaluated by the Macnab outcome criteria. The median follow-up period was 18 months (range 10 to 35 months). The mean Visual Analog Score improved from 8.6 before the surgery to 3.2 after the surgery. Overall, excellent or good outcomes were obtained in 30 (85.7%) of the 35 patients at the last follow-up examination, with both these outcomes showing statistically significant improvement (P<0.01). There were no complications related to the surgery, nor was any spinal instability detected. Three patients (8.6%) experienced persistent radiculopathy and subsequently underwent open microdiscectomy at the same level. We concluded that transforaminal percutaneous endoscopic discectomy is safe and efficacious in the treatment of foraminal or extraforaminal disc herniations. However, proper patient selection is paramount to ensure a satisfactory outcome after decompression of foraminal and extraforaminal disc herniations.

Risk factor for unsatisfactory outcome after lumbar foraminal and far lateral microdecompression

STUDY DESIGN

A retrospective study of consecutive patients who underwent microdecompression for far lateral disc or foraminal stenosis.

OBJECTIVES

To evaluate the risk factors for unsatisfactory outcome.

SUMMARY OF BACKGROUND DATA

There has been no detailed analysis of postoperative radicular pain, although it is not infrequent following foraminal and far lateral microdecompression.

METHODS

A total of 184 patients, who were followed up for more than 2 years, were reviewed. Microdecompression was performed through lateral intermuscular approach. In cases of double herniation (combination of intracanalicular disc at the same level), additional intracanalicular decompression was simultaneously performed. The unsatisfactory outcomes included persistent or recurrent leg pain, based on the Japanese Orthopedic Association leg pain score, and revision surgery at the same level. The potential risk factors, including gender, age, symptom period, preoperative radiologic and intraoperative findings, were determined.

RESULTS

The average follow-up period was 38.4 months, with a maximum 70 months. Forty of the 184 patients (21.7%) had persistent or recurrent leg pain, with nine requiring revision surgeries. The statistically significant risk factor for unfavorable outcomes was double herniation, with odds ratio of 2.89 (P = 0.004).

CONCLUSION

Facet preserving microdecompression is an effective method for foraminal and far lateral root compression. However, in cases of double herniation, total facetectomy is preferable.

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

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

Interlaminar approach for excision of lateral lumbar disc herniation: technical note

STUDY DESIGN

Technical note.

OBJECTIVE

To show that approaching the lateral lumbar disc from the contralateral interlaminar space offers a wider exposure with reduced facet removal.

SUMMARY OF BACKGROUND DATA

The interlaminar approach is a well-established approach for the removal of lateral lumbar disc herniation (LLDH). However, access to the lateral disc space via this approach may be difficult and requires generous facet joint removal.

METHODS

A 41-year-old woman presented with a 2-year history of low back pain and severe left leg pain. Computerized tomography of the lumbar spine revealed a left-sided intraforaminal lateral disc protrusion at L4/5 level.

RESULTS

The patient underwent a left L4/5 discectomy and removal of the lateral disc via the interlaminar approach from the contralateral (right) side with excellent postoperative result.

CONCLUSIONS

The authors present a modification of the interlaminar microsurgical approach for excision of an intraforaminal lateral disc herniation in which the herniated disc is approached from the contralateral interlaminar space through a midline incision. The facet joint removal is less, and the exposure is superior to the traditional interlaminar approach.

Mapeamento do trajeto extraforaminal da raiz L4 no espaço intertransversário L4-L5 através do acesso paramediano à coluna vertebral

As hérnias discais extremolaterais correspondem a 10% das hérnias discais sintomáticas, mais comumente localizadas nos níveis L3-L4 e L4-L5. Por muitos anos, a abordagem cirúrgica das hérnias lombares foraminais e extraforaminais foi feita através de via de acesso posterior mediana com hemilaminectomia e facetectomia total ou parcial. Inúmeras foram as variações propostas para essa técnica a fim de se evitar a facetectomia e suas repercussões biomecânicas, que ocasionavam com certa freqüência o surgimento de dor lombar baixa devido à instabilidade vertebral criada. A abordagem cirúrgica dessa patologia pela via paramediana, entre os músculos multífido e longuíssimo (via de Wiltse), tem a vantagem de poupar o paciente de perdas ósseas e permitir uma visão mais oblíqua do neuro-foramen. Essa abordagem permite, com mínima mobilização da raiz de L4, acesso ao disco L4-L5 e eventuais herniações extra-foraminais do mesmo. Nosso objetivo é apresentar um estudo do trajeto extra-foraminal da raiz de L4 no espaço intertransversário L4-L5. Para isso, foram realizadas dissecções em 10 cadáveres (20 lados) e obtidas as medidas baseadas em 6 parâmetros anatômicos. A análise dos dados nos permite concluir que as hérnias discais extremo-laterais no nível L4-L5 podem ser acessadas com relativa segurança através da via paramediana.

Lateral Lumbar Disc Herniations Treated With a Paraspinal Approach

In this independent review, at an average of 5.5 years after surgical excision of a lateral zone disc herniation using a paraspinal approach, 51 of 60 patients (85%) were satisfied with the results. Pain was eliminated in 36 (60%) and reduced in all but 3 (5%). Two-thirds of patients had no residual weakness or numbness. Thirty patients (50%) developed some new low-grade back pain, 17 (28%) developed some radicular pain, 9 (19%) developed some degree of radiographic instability, and 9 (15%) required further operative procedures. Based on this information, surgeons should be able to provide realistic expectations for their patients regarding outcomes. Based on our review of the literature, results using the paraspinal window appear similar, but not superior, to other available techniques, and the choice of approach should be based on the comfort of the surgeon.