Extraforaminal Disc Herniation Research Articles

Is Close Supervision by a Senior Surgeon Necessary During the Initial Days of Performing Endoscopic Lumbar Discectomy? A Retrospective Comparative Study between Two Fellowship Trained Surgeons to Assess the Learning Curve.

Endoscopic lumbar discectomy is a minimally invasive technique with a steep learning curve. The studies in the literature base the learning curve on the operative duration. We conducted this study to determine the learning curve based on the presence or absence of supervision by an experienced surgeon. This study involved two spine surgeons (surgeon A and surgeon B), who after their fellowship training from the same institute started practising in two different hospitals with different settings. The data of the first 80 patients operated by these two surgeons were extracted, and the patients were followed up for a minimum of 1 year. The data were split into first 30 cases and late 50 cases, which were compared to see the difference between the two surgeons. The first 30 cases were evaluated between the two surgeons, and the most significant difference between the two was the operative duration. There was difference between the two surgeons in approach towards migrated and foraminal/extra foraminal discs (P = 0.02). The surgeon B started operating on upper lumbar levels in his later 50 cases, but the foraminal and extraforaminal disc herniations were rarely treated by surgeon B. Endoscopic discectomy when supervised by senior faculty helps to reduce the operative duration especially in the initial phases of a surgeon's career. The surgeon under the supervision of a senior faculty performs more of migrated and foraminal herniated discs.

Contralateral lower limb radiculopathy by extraforaminal disc herniation following oblique lumbar interbody fusion in degenerative lumbar disorder: illustrative cases.

Contralateral lower limb radiculopathy is a potential early complication of oblique lumbar interbody fusion (OLIF) in degenerative lumbar disorders. Among several pathologies related to contralateral radiculopathy following OLIF, extraforaminal disc herniation during the OLIF procedure is very rare. Case 1 is a 68-year-old male underwent L4-5 and L5-6 OLIF for recurrent lumbar canal stenosis-expressed right leg pain and muscle weakness after surgery. Case 2 is a 76-year-old female on whom L4-5 OLIF was performed for L4 degenerative spondylolisthesis and who presented right leg pain and numbness postoperatively. In both patients, OLIF cages were inserted into the posterior part of the disc space or obliquely and the extraforaminal extruded disc compressed opposite exiting nerve roots (L5 root in case 1 and L4 root in case 2) as shown on magnetic resonance imaging (MRI). Surgical decompression with discectomy was required for pain relief and neurological improvement in both cases. When emerging from new-onset opposite limb radiculopathy attributed to the OLIF procedure, extraforaminal disc herniation should be considered a potential pathology and MRI is useful for early diagnosis and selecting a subsequent management, including surgery.

A Modified Endoscopic Access for Lumbar Foraminal Pathologies; Posterolateral "Intertransverse" Endoscopic Approach to Minimize Postoperative Dysesthesia Following Transforaminal Approach.

To present an innovative, modified endoscopic approach for foraminal/extraforaminal pathologies, to reduce postoperative dysesthesia (POD) following the conventional transforaminal endoscopic approach (the access angle more than 45° from the midline), since POD is one of the major documented disadvantages that may compromise patient satisfaction. We introduce a modified posterolateral technique, termed the intertransverse approach, utilizing a steeper access angle less than 25° through the intertransversarii muscle and the intertransverse space with expanding Kambin triangle via lateral facetectomy/foraminoplasty, to reduce dorsal root ganglion/exiting nerve root irritation under direct visualization and lower the incidence of POD. Consecutive patients undergoing endoscopic spine surgery via the intertransverse approach for foraminal and/or extraforaminal disc herniations or bony stenosis were retrospectively reviewed. Clinical outcomes were reviewed with the primary outcome being POD. Twenty-two patients were included in the review. Patients showed significantly improved clinical outcomes (visual analogue scale leg and back pain and Oswestry Disability Index) postoperatively. There was a low rate of dorsal root ganglion (DRG)-related POD (9.1%, 2 of 22) that was minimal and resolved soon. The inter-transverse endoscopic approach is feasible for lumbosacral foraminal and extraforaminal decompression with significantly improved clinical outcomes and the added advantage of a low rate of DRG-related POD compared to traditionally reported rates in the literature for the conventional transforaminal approach.

Minimally invasive tubular approach for lumbar extraforaminal disc herniation: how I do it.

Minimally invasive surgical resection of extraforaminal disc herniation is challenging. The anatomical landmarks are varying from common interlaminar approach. The main risk is to damage the exiting nerve root as it is not yet protected by any bony structure. Here, we present the different steps of the minimally invasive approach to resect a lumbar extraforaminal disc herniation, using tubular retractor under microscopy. Once the key steps of tubular placements are well known, minimally invasive approach for such extraforaminal resection affords appropriate exposure, while reducing blood loss and muscle injury.

L1 Radiculopathy Caused by L1-L2 Extraforaminal Disc Herniation.

L1 Radiculopathy Caused by L1-L2 Extraforaminal Disc Herniation.

Comparison of Percutaneous Transforaminal Endoscopic Discectomy and Microscope‐Assisted Tubular Discectomy for Lumbar Disc Herniation

ObjectiveThe aim of the present study was to compare the clinical outcomes and quality of life following percutaneous transforaminal endoscopic discectomy (PTED) and microscope‐assisted tubular discectomy (MTD) for lumbar disc herniation (LDH).MethodsThis study had a retrospective design. From June 2017 to June 2018, the clinical data of 120 patients with LDH treated with PTED (60 cases, PTED group) and MTD (60 cases, MTD group) were analyzed and followed up for at least 20 months. There were 59 men and 61 women. Patients were aged between 22 and 80 years. The operation time, intraoperative blood loss, incision length, frequency of intraoperative fluoroscopy, cost, hospital stay, types of herniated discs, complications, and clinical outcomes were evaluated. Clinical outcomes were assessed using the visual analog scale (VAS), the Oswestry disability index (ODI), and the modified Macnab criteria. Short‐Form 36 (SF‐36) and the EQ‐5D‐5L were used to evaluate the quality of life of patients. The data between the two groups were compared by independent sample t‐tests. Multiple comparisons between samples were analyzed by analysis of variance.ResultsCompared with the MTD group, the PTED group had shorter incision length (9.20 ± 1.19 mm vs 26.38 ± 1.82 mm), less intraoperative blood loss (18.00 ± 4.97 mL vs 39.83 ± 6.51 mL), and shorter hospital stay (5.42 ± 5.08 days vs 10.58 ± 3.69 days) (P = 0.00). PTED was much more appropriate for foraminal and extraforaminal disc herniation. The incidence of paresthesia was lower in the PTED group (6.67% vs 16.67%). At each follow up, the VAS and ODI scores of all patients were significantly improved compared with those before surgery (P = 0.00). At 3 days postoperatively, the lumbar VAS score of the PTED group was significantly lower (1.58 ± 1.00 vs 2.37 ± 1.10, P = 0.00). The excellent rate of the PTED group reached 91.67%, and that of the MTD group reached 93.33%. Compared with the preoperative SF‐36 scores for physiological function, mental health, and social function, the postoperative scores were significantly improved in both groups (P = 0.00). The EQ‐5D‐5L in the PTED group increased from 0.30 ± 0.17 before the operation to 0.69 ± 0.13 after 6 months of follow up (P = 0.00) and 0.73 ± 0.14 after 20 months of follow up. The EQ‐5D‐5L in the MTD group increased from 0.28 ± 0.17 before the operation to 0.68 ± 0.13 after a 6‐month follow up (P = 0.00), and 0.73 ± 0.12 after a 20‐month follow up.ConclusionAlthough both PTED and MTD are effective for LDH, PTED is much more appropriate for various types of LDH and has the advantages of the low incidence of low back pain, fewer complications, and early recovery.

Transpars approach for L5-S1 foraminal and extra-foraminal lumbar disc herniations: technical note.

The short pars and the narrowed surgical corridor for far lateral L5S1 herniation make the transpars approach challenging. The aim of this study is to determine the feasibility, efficacy, and safety of the transpars microscopic approach for the treatment of L5-S1 foraminal and extraforaminal lumbar disc herniation. From 2015 to 2019, patients with L5-S1 far lateral lumbar disc herniation were prospectively recruited. Drug intake, working days lost, NRS-leg, NRS-back, nerve-root palsy, Oswestry disability-index, Macnab criteria were recorded before surgery and at follow-up. Patients were seen at 1-6-12 months after surgery. Lumbar dynamic X-rays were performed at 6-12 months after surgery and again at 2-4 years after surgery. Key-steps of surgery are described. Fourteen patients were enrolled. NRS-leg and NRS-back scores significantly improved (from 7.93 to 1.43 and from 3.2 to 0.6, respectively; P<0.0001). Oswestry Score significantly decreased (from 63.14 to 19.36 at 12 months; P<0.0001). L5 Root palsy improved in all cases (from 3.72/5 to 5/5; P<0.0001). At 12-months, excellent or good outcome (Macnab criteria) was achieved in 12 (85.7%) and 2 (14.3%) patients, respectively. All patients who were not retired returned to work within 30 days after surgery. No recurrence, instability or re-operations occurred. The trans pars microscopic approach is feasible, safe, and effective for L5-S1 foraminal and extraforaminal disc herniation. During surgery, the key-point is the oblique working angle, directed caudally, parallel to L5 pedicle. The iliac crest does not seem to constitute an obstacle.

Comparison of Two Minimally Invasive Techniques with Endoscopy and Microscopy for Extraforaminal Disc Herniations

Extraforaminal disc herniations are extraordinary herniations because they are located outside the foraminal bony borders and compress the root exiting at the corresponding level, whereas in median or paramedian herniations, the root 1 level below is compressed. Percutaneous endoscopic discectomy (PED) and microscopic extraforaminal discectomy (MEFD) are 2 popular contemporary techniques that have been performed extensively for these herniations since the 1970s. In this study, we retrospectively analyzed 118 patients who underwent either PED (66 patients) or MEFD (52 patients). All the patients were clinically evaluated for neurologic examination findings, visual analog scale (VAS) scores for leg pain and Oswestry Disability Index (ODI) preoperatively and on the seventh postoperative day as well as 6 and 12 months after surgery. The complication rates and types of both techniques were discussed. The preoperative VAS score and ODI were all comparable. Improvements in VAS scores 6 months postoperatively and improvements in ODI at all follow-up periods were statistically significant in favor of PED. However, there was great discrepancy regarding the postsurgical complications in favor of MEFD. PED is more prone to complications because this technique is strictly dependent on the tubular system and the ideal anatomy of the Kambin triangle. Variations in or degeneration of the Kambin triangle can lead to devastating complications in the PED technique, but normal anatomic conditions are feasible in only approximately 20% of patients. The most important feature of this study was that both techniques were performed by the same experienced team, who developed their own concept.

Surgery for extraforaminal lumbar disc herniation: a single center comparative observational study

BackgroundSurgery on extraforaminal lumbar disc herniation (ELDH) is a commonly performed procedure. Operating on this type of herniation is known to come with more difficulties than on the frequently seen paramedian lumbar disc herniation (PLDH). However, no comparative data are available on the effectiveness and safety of this operation. We sought out to compare clinical outcomes at 1 year following surgery for ELDH and PLDH.MethodsData were collected through the Norwegian Registry for Spine Surgery (NORspine). The primary outcome measure was change at 1 year in the Oswestry Disability Index (ODI). Secondary outcome measures were quality of life measured with EuroQol 5 dimensions (EQ-5D); and numeric rating scales (NRSs).ResultsData of a total of 1750 patients were evaluated in this study, including 72 ELDH patients (4.1%). One year after surgery, there were no differences in any of the patient reported outcome measurements (PROMs) between the two groups. PLDH and ELDH patients experienced similar changes in ODI (− 30.92 vs. − 34.00, P = 0.325); EQ-5D (0.50 vs. 0.51, P = 0.859); NRS back (− 3.69 vs. − 3.83, P = 0.745); and NRS leg (− 4.69 vs. − 4.46, P = 0.607) after 1 year. The proportion of patients achieving a clinical success (defined as an ODI score of less than 20 points) at 1 year was similar in both groups (61.5% vs. 52.7%, P = 0.204).ConclusionsPatients operated for ELDH reported similar improvement after 1 year compared with patients operated for PLDH.

Coronal magnetic resonance imaging of three-dimensional fast-field echo with water-selective excitation improves the sensitivity and reliability of identification of extraforaminal lumbar disc herniation

ObjectiveThe complete view of the nerve root, including the extraforaminal zone, can be displayed by coronal magnetic resonance imaging (MRI) of three-dimensional (3D) fast-field echo with water-selective excitation (CMRI). However, its sensitivity, specificity, and reliability for the diagnosis of extraforaminal lumbar disc herniation are unclear. We compared the sensitivity, specificity, and reliability of conventional MRI, CMRI, and 3D MRI for the identification of extraforaminal lumbar disc herniation.MethodsThis study involved 140 patients (68 with extraforaminal lumbar disc herniation and 72 with paramedian disc herniation). Their mean age was 44.57 ± 14.59 years. Conventional MRI, CMRI, and 3D MRI of all patients were evaluated by five experts. The reliability, sensitivity, and specificity of the three imaging techniques for identification of extraforaminal lumbar disc herniation were compared using kappa statistics and the chi-squared test.ResultsCMRI showed higher agreement (0.843) than conventional MRI (0.671) and 3D MRI (0.771) for the identification of extraforaminal lumbar disc herniation. CMRI demonstrated higher sensitivity (95.6% vs. 91.2%) than conventional MRI (85.3% vs. 70.6%) and 3D MRI (92.6% vs. 86.7%) regardless of whether performed by junior or senior surgeons.ConclusionsCMRI is helpful for identification of extraforaminal disc herniation by junior and senior orthopedic surgeons.

Endoscopic Transforaminal Discectomy Vs. Far Lateral Discectomy for Extraforaminal Disc Protrusions: Our Experience

Background: Extraforaminal disc herniations are challenging occurrences, requiring a more disruptive approach in terms of bony removal and muscles dissection. We compared outcomes and intraoperative findings between endoscopic transforaminal and far lateral discectomy in the treatment of extraforaminal disc protrusions Methods: We prospectively collected 38 patients who underwent surgery for lumbar extraforaminal disc prolapse, from January 2014 to December 2018. Twenty patients underwent far lateral microsurgical discectomy, whereas eighteen a percutaneous transforaminal endoscopic discectomy. Patients were randomly assigned to a treatment group and were followed-up at intervals of 3, 6, and 16 months. No patients were lost at follow-up. Data were collected on leg pain and disability degree, preoperatively and at follow-up visits, along with demographic data, operative time, amount of intraoperative blood loss, and any postoperative surgical adverse events. Eventually, data analyzed and compared between the two groups. Results: Mean operative time was significantly shorter for endoscopically treated patients compared to patients who underwent microdiscectomy (59.4 vs. 98 minutes, p-value < 0.001). Also, intraoperative blood loss was almost negligible (< 50 ml) for all endoscopically treated patients. There were no differences in terms of postoperative outcomes between patients treated with standard microsurgical techniques and patient who underwent endoscopic transforaminal discectomy at 3, 6, and 16 months of follow-up. Conclusions: transforaminal endoscopic discectomy is a feasible and safe procedure for the treatment of extraforaminal lumbar disc herniation. Our series highlighted the utility and feasibility of the technique, showing similar results to far lateral microsurgical technique.

Percutaneous Endoscopic Transforaminal Outside-In Outside Technique for Foraminal and Extraforaminal Lumbar Disc Herniations—Operative Technique

Different transforaminal endoscopic approaches have been developed for the surgical treatment of lumbar disc herniation: Kambin (intradiscal), Yeung (intraforaminal intradiscal), Ruetten (extreme lateral), transforaminal endoscopic surgical system (intraforaminal extradiscal) approach, and modifications. The operative technique for the treatment of foraminal and extraforaminal lumbar disc herniation through these surgical approaches has not been well described in reported studies. Moreover, each of these surgical approaches has limitations in the removal of migrated intra- or extraforaminal disc herniation. We have described, step by step, the operative technique of a modified percutaneous endoscopic transforaminal approach we have termed the "percutaneous endoscopic intra- and extraforaminal extradiscal approach or transforaminal outside-in outside [TOIO] approach" for the treatment of foraminal and extraforaminal lumbar disc herniation. From 2012 to 2018, 48 patients had undergone the percutaneous endoscopic TOIO approach for symptomatic foraminal and extraforaminal lumbar disc herniation. The inclusion criteria were the same as the microdiscectomy criteria. The exclusion criteria included patients with severe foraminal stenosis and disc degeneration, listhesis, and scoliosis. The pre- and postoperative clinical data, radiographic findings, and surgical technique were investigated. No intraoperative complications developed. All the patients showed progressive improvement of initial neurological deficits with complete recovery of motor weakness and L4, L5 hypoesthesia at 1 month postoperatively. One patient experienced persistent postoperative dysesthesia on the affected leg for ∼1 month. The percutaneous endoscopic TOIO approach is a minimally invasive, safe, and efficacious surgical procedure for the treatment of lumbar foraminal and extraforaminal disc herniation. Proper patient selection is mandatory to ensure a satisfactory outcome.

Endoscopic Treatment of Extraforaminal Entrapment of L5 Nerve Root (Far Out Syndrome) by Unilateral Biportal Endoscopic Approach: Technical Report and Preliminary Clinical Results.

ObjectiveFar out syndrome is compression and entrapment of the L5 nerve root in the extraforaminal area between the hypertrophied L5 transverse process and the sacral ala. The purpose of this study was to describe the technique of unilateral biportal endoscopic decompression for far out syndrome and to analyze early clinical results after endoscopic decompression. MethodsThe authors consecutively performed operative treatments for 16 patients with unilateral extraforaminal entrapment of the L5 nerve root (far out syndrome) using percutaneous biportal endoscopies. We included only patients who were followed more than six months after surgery. Demographic characteristics, operative time, concomitant herniated disc, and surgical complications were investigated. Clinical outcomes were evaluated using modified MacNab criteria, the visual analogue scale (VAS) for legs, and the Oswestry Disability Index (ODI). ResultsAmong 16 patients, a total of 14 cases with 4 males and 10 females were included in the study. The mean leg VAS and the ODI were significantly improved after unilateral biportal endoscopic surgery. Concomitant extraforaminal disc herniation was associated with a favorable outcome (p<0.05). Abdominal pain in the immediate postoperative period occurred in 2 patients. Abdominal pain was completely resolved with conservative management in both patients. ConclusionWe were able to achieve successful decompression of unilateral extraforaminal entrapment of the L5 nerve root using unilateral biportal endoscopic surgery. A unilateral biportal endoscopic approach may be considered as an alternative surgical treatment for far out syndrome.

Percutaneous Stenoscopic Lumbar Decompression with Paramedian Approach for Foraminal/Extraforaminal Lesions.

The lumbar foramen is affected by different degenerative diseases, including extraforaminal disc herniation, foraminal stenosis (FS), and degenerative or spondylolytic spondylolisthesis. The purpose of this study was to describe percutaneous stenoscopic lumbar decompression with a paramedian approach (para-PSLD) for foraminal/extraforaminal lesions. All operative procedures were performed using a complete uniportal endoscopic instrument system. The para-PSLD can be easily applied to patients with FS and narrow disc space or facet joint hypertrophy. The anatomical view of a para-PSLD is similar to that of a conventional open surgery and allows for good visualization of the foraminal/extraforaminal areas. We suggest that para-PSLD is an alternative and minimally invasive procedure to treat degenerative lumbar foraminal/extraforaminal stenoses.

A Modified Percutaneous Endoscopic Technique to Remove Extraforaminal Disk Herniation at the L5-S1 Segment

To introduce a modified percutaneous endoscopic lumbar diskectomy (PELD) technique to remove extraforaminal disk herniation at the L5-S1 segment, including the technical essentials and preliminary results. The geometric parameters of the transverse process, facet joint, and sacrum (TFS) space based on imaging examination were measured in 100 common patients. The technical essentials, including working cannula placement and disk removal involved in the technique, were described. Ten cases (7 men and 3 women) with extraforaminal disk herniation at L5-S1 were surgically treated with the PELD technique through the TFS space from June 2015 to March2017. The maximum diameter of the TFS space varied from 2.73 to 11.81 mm (6.84 ± 2.01 mm) on the left and 3.00 to 10.47 mm (7.02 ± 2.05 mm) on the right. The distance of possible skin entry points from midline varied from 33.28 to 84.18 mm, and the distance of external iliac vessels to skin varied from 70.05 to 119.14 mm. All 10 patients who underwent the modified PELD technique were back to previous activities in 1 month. Visual analog scale (VAS) or Oswestry Disability Index (ODI) scores reduced to 2.5 ± 2.0 or 25.4 ± 10.8 from 7.5 ± 1.3 or 75.2 ± 13.3, respectively, 1 day after operation. At 30 days after the operation, the VAS score was 1.0 ± 0.6 and ODI score was 10.2 ± 3.2. No neurologic deficit or surgical site infection occurred. We introduced a modified PELD technique to remove extraforaminal disk herniation at the L5-S1 segment. This technique was less invasive, effective, and safe. We also summarized a detailed protocol to identify and remove the herniated disk for nerve protection.

Usefulness of Oblique Lumbar Magnetic Resonance Imaging for Nerve Root Anomalies and Extraforaminal Entrapment Lesions.

Study DesignA retrospective review of prospectively evaluated magnetic resonance (MR) images.Purpose Routine lumbar axial and sagittal MR images may not clearly demonstrate nerve root anomalies and entrapments in the extraforaminal region. Thus, lumbar extraforaminal lesions or nerve root anomalies may be underdiagnosed because of unfamiliar radiological anatomy. We aimed to investigate the clinical efficacy of our oblique magnetic resonance imaging (MRI) technique for diagnosing nerve root anomalies and entrapment lesions.Overview of LiteratureEvaluation of clinical usefulness of oblique lumbar MRI for nerve root anomalies and extraforaminal entrapment lesions.MethodsIn total, 162 patients (60 males and 102 females; mean age, 59.8±17.8 years) with suspected nerve root anomalies and entrapments in routine axial and sagittal MR images underwent unilateral or bilateral oblique lumbar T2-weighted MRI. The axial angle of the oblique image was parallel to the foramen. The oblique MRI findings of the symptomatic side were compared with those of the asymptomatic side in cases with unilateral pathologic lesions. Interobserver agreement was analyzed using kappa statistics.ResultsThe following abnormal findings were obtained: nerve root entrapment due to foraminal stenosis in 82 cases; extraforaminal disk herniation in 29; conjoined nerve root in six; and foraminal bony cyst in one. Forty-three of the 46 patients experienced unilateral lateralizing symptoms, unilateral nerve root entrapment due to foraminal stenosis, herniated disk, and extraforaminal bony cyst compared with the asymptomatic contralateral side (p <0.05).Conclusions Our results suggest that oblique lumbar MRI is a simple and valuable modality for diagnosing anomalous lumbar nerve root lesions and entrapment.

Recurrent upper lumbar disc herniation treated via the transforaminal approach using microendoscopy-assisted lumbar discectomy: a case report

BackgroundAlthough microendoscopy-assisted lumbar discectomy for lateral or extraforaminal lumbar disc herniations via the lateral approach has previously been reported, microendoscopy-assisted lumbar discectomy for central or paramedian disc herniations via the lateral approach has not been reported.We report the first case of recurrent upper lumbar disc herniation (L2–L3) treated with microendoscopy-assisted lumbar discectomy via the transforaminal approach. No microendoscopy-assisted lumbar discectomy for recurrent upper lumbar disc herniation via the transforaminal approach has previously been reported. Percutaneous endoscopic lumbar discectomy via the transforaminal approach is very useful as a minimally invasive surgery for disc herniations. We applied percutaneous endoscopic lumbar discectomy via the transforaminal approach, and invented a new microendoscopy-assisted lumbar discectomy via the transforaminal approach.Case presentationA 79-year-old Japanese man was operatively managed for recurrent L2–L3 herniation. An 18 mm skin incision was made approximately 70 mm from the midline to the lateral side to allow a sufficiently angled trajectory to the extraforaminal space. The transforaminal approach was used. The exiting nerve root was identified along its course inferior to the pedicle. The lateral portion of the pars interarticularis and the facet joint was removed using a high-speed drill under the guidance of an endoscope. The tip of the endoscope was set at the lateral side of the dura mater. The dura mater was retracted medially and gently, and the herniated disc fragments were removed safely. All symptoms were relieved postoperatively. Postoperative magnetic resonance imaging demonstrated disappearance of all herniated disc fragments. A postoperative three-dimensional computed tomographic scan demonstrated the complete preservation of the facet joint.ConclusionsThis is the first report of a case of recurrent upper lumbar disc herniation treated with microendoscopy-assisted lumbar discectomy via the transforaminal approach. This procedure allows for the use of a nerve retractor and other instruments to detach adhesions from the dura mater. This procedure has the advantages of clear visualization of the dura mater, exiting nerve root, and traversing nerve root, and diminished risk of nerve injury, and complete preservation of the articular surface of the facet joint.

Extraforaminal microscopic assisted percutaneous nucleotomy for foraminal and extraforaminal lumbar disc herniations

BackgroundForaminal and extraforaminal lumbar disc herniations are uncommon. The main presentation is radicular pain related to the exiting nerve root at the affected level. Different approaches for surgical intervention have been described. PurposeThis study aimed to evaluate the clinical outcome, complications recurrence, and reoperation rate of extraforaminal microscopic-assisted percutaneous nucleotomy, with literature review focusing on complications and recurrence rate. Study DesignThis is a prospective cohort study done in a high-flow spine center in Germany. Patient SampleBetween October 2012 and October 2015, 76 patients (35 women and 41 men) with foraminal or extraforaminal lumbar disc prolapse were operated on. Outcome MeasuresThe following were the outcome measures: (1) self-report measures: Visual Analogue Scale (VAS) for leg pain and back pain; (2) physiological measures: standing plain X-rays (anterioposterior, lateral, and dynamic views); and (3) functional measures: Oswestry Disability Index (ODI) (validated German version) and Odom's criteria. MethodsAll patients were operated upon with trans-tubular extraforaminal microscopic-assisted percutaneous nucleotomy (EF-MAPN) technique. Preoperative clinical and neurologic evaluations were done. The mean follow-up period was 38 months (range 12–54). The study has not received funding for research from any organization. All authors do not have any conflict of interest. ResultsThe mean age was 54 years. The most commonly affected level was L4/L5 (34 patients). The mean preoperative VAS for leg pain was 7.6 (3–10), which improved to 1.4 (0–4) postoperatively. The average operative time was 57.5 minutes. There were no intraoperative complications. One patient had temporary postoperative quadriceps weakness (L4 radiculopathy) that was completely improved at 3 months' follow-up. Another patient had deep venous thrombosis after discharge. Two patients had recurrences that necessitated another operation within the first 6 months postoperatively. Both were followed up for 1 year without a second recurrence. ConclusionTrans-tubular percutaneous extraforaminal microscopic-assisted nucleotomy is effective for foraminal and extraforaminal disc herniations. It is a muscle-splitting minimally invasive approach with minimal morbidity. Complications, recurrence, and reoperation rate are not different compared with microsurgical open or endoscopic techniques.

Atypical anatomy associated with a lumbar far lateral disc herniation

Abstract Far lateral disc herniation is an uncommon but potentially significant cause of intractable leg pain associated with compression of the exiting nerve root and associated dorsal root ganglion. Since far lateral disc herniations are located outside the spinal canal, several minimally invasive paraspinal muscle-splitting techniques have been developed that allow for neural decompression with reduced soft tissue and bony trauma compared with conventional midline approaches. However, minimally invasive approaches require familiarity with the microsurgical anatomy of the extra-foraminal compartment because of the limited exposure. We report a case of an atypical anatomic relationship identified during far lateral discectomy involving a disc fragment located in a superolateral location relative to the exiting nerve root rather than the more common inferomedial location. This report highlights that familiarity with atypical locations of an extra-foraminal disc herniation and careful exploration of all quadrants in the surgical field is important during minimally invasive far lateral discectomy.

Diagnosis of Nerve Root Compromise of the Lumbar Spine: Evaluation of the Performance of Three-dimensional Isotropic T2-weighted Turbo Spin-Echo SPACE Sequence at 3T

ObjectiveTo explore the performance of three-dimensional (3D) isotropic T2-weighted turbo spin-echo (TSE) sampling perfection with application optimized contrasts using different flip angle evolution (SPACE) sequence on a 3T system, for the evaluation of nerve root compromise by disc herniation or stenosis from central to extraforaminal location of the lumbar spine, when used alone or in combination with conventional two-dimensional (2D) TSE sequence.Materials and MethodsThirty-seven patients who had undergone 3T spine MRI including 2D and 3D sequences, and had subsequent spine surgery for nerve root compromise at a total of 39 nerve levels, were analyzed. A total of 78 nerve roots (48 symptomatic and 30 asymptomatic sites) were graded (0 to 3) using different MRI sets of 2D, 3D (axial plus sagittal), 3D (all planes), and combination of 2D and 3D sequences, with respect to the nerve root compromise caused by posterior disc herniations, lateral recess stenoses, neural foraminal stenoses, or extraforaminal disc herniations; grading was done independently by two readers. Diagnostic performance was compared between different imaging sets using the receiver operating characteristics (ROC) curve analysis.ResultsThere were no statistically significant differences (p = 0.203 to > 0.999) in the ROC curve area between the imaging sets for both readers 1 and 2, except for combined 2D and 3D (0.843) vs. 2D (0.802) for reader 1 (p = 0.035), and combined 2D and 3D (0.820) vs. 3D including all planes (0.765) for reader 2 (p = 0.049).ConclusionThe performance of 3D isotropic T2-weighted TSE sequence of the lumbar spine, whether axial plus sagittal images, or all planes of images, was not significantly different from that of 2D TSE sequences, for the evaluation of nerve root compromise of the lumbar spine. Combining 2D and 3D might possibly improve the diagnostic accuracy compared with either one.