Full-endoscopic anterior decompression versus conventional anterior decompression and fusion in cervical disc herniations

Polyurethane on titanium unconstrained disc arthroplasty versus anterior discectomy and fusion for the treatment of cervical disc disease: a review of level I-II randomized clinical trials including clinical outcomes

PURPOSE

To contrast the clinical and radiologic outcomes and adverse events of anterior cervical discectomy and fusion (ACDF) with a single cervical disc arthroplasty design, the polyurethane on titanium unconstrained cervical disc (PTUCD).

METHODS

This is a systematic review of randomized clinical trials (RCT) with evidence level I-II reporting clinical outcomes. After a search on different databases including PubMed, Cochrane Central Register of Controlled Trials, and Ovid MEDLINE, a total of 10 RCTs out of 51 studies found were entered in the study. RTCs were searched from the earliest available records in 2005 to November 2014.

RESULTS

Out of a total of 1101 patients, 562 were randomly assigned into the PTUCD arthroplasty group and 539 into the ACDF group. The mean follow-up was 30.9 months. Patients undergoing arthroplasty had lower Neck Disability Index, and better SF-36 Physical component scores than ACDF patients. Patients with PTUCD arthroplasty had also less radiological degenerative changes at the upper adjacent level. Overall adverse events were twice more frequent in patients with ACDF. The rate of revision surgery including both adjacent and index level was slightly higher in patients with ACDF, showing no statistically significant difference.

CONCLUSIONS

According to this review, PTUCD arthroplasty showed a global superiority to ACDF in clinical outcomes. The impact of both surgical techniques on the cervical spine (radiological spine deterioration and/or complications) was more severe in patients undergoing ACDF. However, the rate of revision surgeries at any cervical level was equivalent for ACDF and PTUCD arthroplasty.

Learning curve of full-endoscopic technique through interlaminar approach for L5/S1 disk herniations

Although minimally invasive full-endoscopic (FE) spine surgery through the interlaminar approach has proved safe and effective for surgical treatment of lumbar disk herniation, the learning curve of the procedure has not been sufficiently established. The purpose of this study is to determine the learning curve for the FE surgery through interlaminar approach for treating the L5/S1 disk herniation. Thirty-six patients with lumbar disk herniation (L5/S1 segment) who underwent FE lumbar discectomy through the interlaminar approach between March 2011 and March 2012 were equally divided into Group A, B, and C by the study time of the surgeons. Clinical evaluation data included perioperative parameters (operative duration, intraoperative blood loss, and the amount of intraoperative bone and ligament excision), clinical curative effect index [visual analog scale (VAS) score for leg and back pain], complications, and the rate of conversion to open surgery. The operation duration, intraoperative bleeding, and the amount of bone and ligament excision were gradually and significantly reduced in the Groups A, B, and C (P < 0.01) and reflected in steep curves of proficiency suggesting that the rate of learning was fast. The VAS scores of leg and back pain were significantly improved (P < 0.01) and no symptomatic recurrence was noticed during the follow-up period (1-1.5 years). The outcomes the three groups were not significantly different. The clinical outcomes of the minimally invasive surgery for the treatment of L5/S1 segment disk herniation through the interlaminar approach were excellent suggesting of a satisfactory curative effect. The steep learning curves of perioperative parameters plotted against the number of surgeries conducted suggest that proficiency can be reached reasonably fast.

Rates of anterior cervical discectomy and fusion after initial posterior cervical foraminotomy

BACKGROUND CONTEXT

In select patients, posterior cervical foraminotomy (PCF) and anterior cervical discectomy and fusion (ACDF) result in similar clinical outcomes when used to treat cervical radiculopathy. Nonetheless, ACDF is performed more frequently, in part because of surgeon perception that PCF requires operative revisions more frequently. The present study investigates the rate of ACDF reoperation at the index level after initial PCF.

PURPOSE

To determine the rate of ACDF after initial PCF and to further describe any patient characteristics or preoperative or operative data that increase the rate of reoperation after PCF.

STUDY DESIGN

Retrospective chart review.

METHODS

Demographic, operative, and reoperation information was collected from the electronic medical records for all patients who underwent PCF at one institution between 2004 and 2011. All patients were subsequently contacted by telephone to identify postoperative complications and more conclusively determine whether any revision operation was performed at the index level.

RESULTS

One hundred seventy-eight patients who underwent a PCF were reviewed, with an average follow-up of 31.7 months. Nine (5%) patients underwent an ACDF revision operation at the index level. The reason for reoperation in these patients included cervical radiculopathy, foraminal stenosis, disc herniation, and cervical spondylosis. Patients who subsequently underwent ACDF at the index level were significantly younger (25 vs. 35 years, p=.03), had lower body mass index (25 vs. 29, p=.01), and more likely to take anxiolytic (56% vs. 22%, p=.04) or antidepressant medication (67% vs. 27%, p=.02), compared with those that did not have a revision operation.

CONCLUSIONS

This is the first study to determine conversion to ACDF after PCF. The present study demonstrates that PCF is associated with a low reoperation rate, similar to the historical reoperation for ACDF. Accordingly, spine surgeons can operate via a PCF approach without a significant increased risk for ACDF revision surgery at the index level.

Changes in cervical sagittal alignment after single-level posterior percutaneous endoscopic cervical diskectomy

Study Design Case series. Objective Posterior percutaneous endoscopic cervical diskectomy (PECD) can preserve the disk in patients with a foraminal disk herniation. However, progressive angulation at the operated segment is a concern, especially for patients with cervical lordosis < 10 degrees. The change in cervical lordosis after posterior PECD was analyzed. Methods Medical records were reviewed of 32 consecutive patients (22 men, 10 women; mean age, 49 ± 12 years) who had single-level foraminal soft disk herniation. The operation levels were as follows: C4-5 in 1 patient, C5-6 in 12, C6-7 in 18, and C7-T1 in 1. All patients were discharged the day after the operation, and neck motion was encouraged. All patients were followed for 30 ± 7 months (range, 24 to 46 months), and 21/32 patients (66%) had radiographs taken at 25 ± 11 months (range, 12 to 45 months). Radiologic parameters were assessed, including cervical curvature (C2-7), segmental Cobb's angle (SA), and anterior and posterior disk height (AH and PH, respectively) at the operative level. Results At the last follow-up, 29/32 patients (91%) had no or minimal pain, and 3/32 patients had occasional pain. SA, AH, and PH were not significantly changed. Cervical lordosis < 10 degrees was present in 10/21 patients preoperatively and in 3/21 patients at the last follow-up. For patients with cervical lordosis < 10 degrees, cervical curvature changed from -2.5 ± 8.0 to -11.3 ± 9.3 degrees (p = 0.01). For patients with cervical lordosis ≥ 10 degrees, cervical curvature changed from -17.5 ± 5.8 to -19.9 ± 5.7 degrees (p = 0.24). Conclusions Cervical curvature does not worsen after posterior PECD.

Treatment of lumbar disc herniations by interventional fluoroscopy-guided endoscopy

The neurointerventional transforaminal endoscopic approach to sequestered disk herniation is a minimally invasive alternative to established microsurgical techniques. In addition to those techniques approaching the nucleus like APLD, the transforaminal approach allows the removal of dislocated sequesters in the epidural space. The main steps of the procedure are fluoroscopy-guided, so a good experience with fluoroscopy based interventional techniques is helpful, but the technique has a significant learning curve. If familiar with the different steps, it allows nearly every lumbar disk herniation to be treated with a very short hospital stay and short rehabilitation time. The paper describes in detail the steps of the procedure, the difficulties and advantages and gives a short review of the relevant literature.

Treatment of lumbar disc herniations by interventional fluoroscopy-guided endoscopy

The neurointerventional transforaminal endoscopic approach to sequestered disk herniation is a minimally invasive alternative to established microsurgical techniques. In addition to those techniques approaching the nucleus like APLD, the transforaminal approach allows the removal of dislocated sequesters in the epidural space. The main steps of the procedure are fluoroscopy-guided, so a good experience with fluoroscopy based interventional techniques is helpful, but the technique has a significant learning curve. If familiar with the different steps, it allows nearly every lumbar disk herniation to be treated with a very short hospital stay and short rehabilitation time. The paper describes in detail the steps of the procedure, the difficulties and advantages and gives a short review of the relevant literature.

Minimally invasive versus open surgery for cervical and lumbar discectomy: a systematic review and meta-analysis

INTRODUCTION

Minimally invasive surgery for discectomy may accelerate recovery and reduce pain, but it also requires technical expertise and is associated with increased risks. We performed a meta-analysis to determine the effects of minimally invasive versus open surgery on functional outcomes, pain, complications and reoperations among patients undergoing cervical or lumbar discectomy.

METHODS

We searched MEDLINE, Embase and the Cochrane Library for reports of relevant randomized controlled trials published to Jan. 12, 2014. Two reviewers assessed the eligibility of potential reports and the risk of bias of included trials. We analyzed functional outcomes and pain using standardized mean differences (SMDs) that were weighted and pooled using a random-effects model.

RESULTS

We included 4 trials in the cervical discectomy group (n = 431) and 10 in the lumbar discectomy group (n = 1159). Evidence overall was of low to moderate quality. We found that minimally invasive surgery did not improve long-term function (cervical: SMD 0.11, 95% confidence interval [CI] -0.09 to 0.31; lumbar: SMD 0.04, 95% CI -0.11 to 0.20) or reduce long-term extremity pain (cervical: SMD -0.21, 95% CI -0.52 to 0.10; lumbar: SMD 0.08, 95% CI -0.16 to 0.32) compared with open surgery. The evidence suggested overall higher rates of nerve-root injury (risk ratio [RR] 1.62, 95% CI 0.45 to 5.84), incidental durotomy (RR 1.56, 95% CI 0.80 to 3.05) and reoperation (RR 1.48, 95% CI 0.97 to 2.26) with minimally invasive surgery than with open surgery. Infections were more common with open surgery than with minimally invasive surgery (RR 0.24, 95% CI 0.04 to 1.38), although the difference was not statistically significant.

INTERPRETATION

Current evidence does not support the routine use of minimally invasive surgery for cervical or lumbar discectomy. Well-designed trials are needed given the lack of high-quality evidence.

Minimally invasive versus open surgery for cervical and lumbar discectomy: a systematic review and meta-analysis

INTRODUCTION

Minimally invasive surgery for discectomy may accelerate recovery and reduce pain, but it also requires technical expertise and is associated with increased risks. We performed a meta-analysis to determine the effects of minimally invasive versus open surgery on functional outcomes, pain, complications and reoperations among patients undergoing cervical or lumbar discectomy.

METHODS

We searched MEDLINE, Embase and the Cochrane Library for reports of relevant randomized controlled trials published to Jan. 12, 2014. Two reviewers assessed the eligibility of potential reports and the risk of bias of included trials. We analyzed functional outcomes and pain using standardized mean differences (SMDs) that were weighted and pooled using a random-effects model.

RESULTS

We included 4 trials in the cervical discectomy group (n = 431) and 10 in the lumbar discectomy group (n = 1159). Evidence overall was of low to moderate quality. We found that minimally invasive surgery did not improve long-term function (cervical: SMD 0.11, 95% confidence interval [CI] -0.09 to 0.31; lumbar: SMD 0.04, 95% CI -0.11 to 0.20) or reduce long-term extremity pain (cervical: SMD -0.21, 95% CI -0.52 to 0.10; lumbar: SMD 0.08, 95% CI -0.16 to 0.32) compared with open surgery. The evidence suggested overall higher rates of nerve-root injury (risk ratio [RR] 1.62, 95% CI 0.45 to 5.84), incidental durotomy (RR 1.56, 95% CI 0.80 to 3.05) and reoperation (RR 1.48, 95% CI 0.97 to 2.26) with minimally invasive surgery than with open surgery. Infections were more common with open surgery than with minimally invasive surgery (RR 0.24, 95% CI 0.04 to 1.38), although the difference was not statistically significant.

INTERPRETATION

Current evidence does not support the routine use of minimally invasive surgery for cervical or lumbar discectomy. Well-designed trials are needed given the lack of high-quality evidence.

Anterior or posterior approach of full-endoscopic cervical discectomy for cervical intervertebral disc herniation? A comparative cohort study

STUDY DESIGN

This is a retrospective comparative cohort study.

OBJECTIVE

To compare the outcomes of patients with symptomatic cervical intervertebral disc herniation (CIVDH) treated with full-endoscopic cervical discectomy (FECD) using the anterior approach with those treated with the posterior approach.

SUMMARY OF BACKGROUND DATA

The optimal FECD surgical approach for CIVDH remains controversial.

METHODS

From March 2010 to July 2012, a total of 84 consecutive patients with symptomatic single-level CIVDH who underwent FECD using the anterior approach (42 patients) or the posterior approach (42 patients) were enrolled. Patients were assessed neurologically before surgery and followed up at regular outpatient visits. The clinical outcomes were evaluated using the visual analogue scale and the modified MacNab criteria. Radiographical follow-up included the static and dynamic cervical plain radiographs, computed tomographic scans, and magnetic resonance images.

RESULTS

In both groups, shorter mean operative time (63.5 min vs. 78.5 min), increased mean volume of disc removal (0.6 g vs. 0.3 g), larger mean decrease in the final postoperative mean intervertebral vertical height (1.0 mm vs. 0.5 mm), and longer mean hospital stay (4.9 d vs. 4.5 d) were observed in the anterior full-endoscopic cervical discectomy group. Postoperatively, the clinical outcomes of the 2 approaches were significantly improved, but the differences between the 2 approaches were not significant (P = 0.211 and P = 0.257, respectively). Four surgery-related complications were observed among all enrolled patients (complications in each group were 2; overall 4 of 84, 4.8%).

CONCLUSION

In our study, the clinical outcomes between the 2 approaches did not differ significantly. Nevertheless, posterior full-endoscopic cervical discectomy may be preferable when considering the volume of disc removal, length of hospital stay, and the postoperative radiographical changes. As an efficacious supplement to traditional open surgery, FECD is a reliable alternative treatment of CIVDH and its optimal approach remains open to discussion.

LEVEL OF EVIDENCE

3.

Minimally invasive surgery with spotlight work channel system in the treatment of lumbar disc herniation: a retrospective study of 21 cases

A group of lumbar discherniation cases was treated with posterior discectomy and decompression with Spotlight working channel. We retrospectively studied these patients. To study and analyze the clinical efficacy and technical features of discectomy which is carried out with the Spotlight channel technology. The development of the minimally invasive spine surgery technology promotes new instruments and materials. For minimally invasive spine surgery in channel technology, the newly launched Depuy(Spine) working channel-Spotlight, which is a new generation of wide viewing angle, single-hole device for minimally invasive spine operations, has good prospects for clinical application. From March 2011 to March 2012, 21 patients who were diagnosed with lumbar disc herniation were treated with posterior discectomy and decompression with Spotlight working channel, then the lumbar and leg pain visual analogue scale (VAS) scores of before and after surgery and that of the follow-ups and the Oswestry Disability Index were analyzed. All patients were successfully operated, and also they received follow-ups for more than 1 year. The postoperative lumbar and leg pain VAS scores improved significantly compared with the preoperative ones (P < 0.05) and can effectively maintain (P > 0.05). The three time points of lumbar pain VAS were 7.80 ± 0.49, 1.51 ± 0.52 and 1.47 ± 0.59. The leg pain VAS were 7.53 ± 0.50, 1.58 ± 0.58 and 1.49 ± 0.67. During the follow-ups of the cases in this group, no case of disc herniation relapsed. Patients were satisfied with that. The Spotlight channel system is one of the surgical approaches to "minimally invasive spine technology with direct vision". It has a good range of surgical indications. It can be carried out flexibly and used widely, which means it will be easier for the surgeons to master.

Percutaneous endoscopic intra-annular subligamentous herniotomy for large central disc herniation: a technical case report

STUDY DESIGN

Technical case report.

OBJECTIVE

To describe the novel technique of percutaneous endoscopic herniotomy using a unilateral intra-annular subligamentous approach for the treatment of large centrally herniated discs.

SUMMARY OF BACKGROUND DATA

Open discectomy for large central disc herniations may have poor long-term prognosis due to heavy loss of intervertebral disc tissue, segmental instability, and recurrence of pain.

METHODS

Six consecutive patients who presented with back and leg pain, and/or weakness due to a large central disc herniation were treated using percutaneous endoscopic herniotomy with a unilateral intra-annular subligamentous approach.

RESULTS

The patients experienced relief of symptoms and intervertebral disc spaces were well maintained. The annular defects were noted to be in the process of healing and recovery.

CONCLUSION

Percutaneous endoscopic unilateral intra-annular subligamentous herniotomy was an effective and affordable minimally invasive procedure for patients with large central disc herniations, allowing preservation of nonpathological intradiscal tissue through a concentric outer-layer annular approach.

Operation of Lumbar Zygoapophyseal Joint Cysts Using a Full-Endoscopic Interlaminar and Transforaminal Approach

In appropriate situations, extensive decompression with laminectomy often continues to be described as the method of choice for operations involving lumbar zygoapophyseal joint (z-joint) cysts. Tissue-sparing procedures are nevertheless becoming more common. Endoscopic techniques have become the standard procedures in many areas because of the advantages they offer in terms of surgical technique and in rehabilitation. One key aspect in spinal surgery was the development of instruments for sufficient bone resection carried out under continuous visual control. This enabled endoscopes to be used when operating on z-joint cysts. The objective of this prospective study was to examine the technical possibilities for the full-endoscopic interlaminar and transforaminal technique in lumbar z-joint cysts. A total of 74 patients were followed up for 2 years. The results show that 85% of the patients no longer have any leg pain or that the pain had been almost completely eliminated, and 11 % experience occasional pain. The complication rate was low. The full-endoscopic techniques brought advantages in the following areas: operation, complications, traumatization, and rehabilitation. The recorded results show that full-endoscopic resection of a z-joint cyst using an interlaminar and transforaminal approach provides an adequate and safe supplement, and is an alternative to conventional procedures when the indication criteria are fulfilled. It also offers the advantages of a minimally invasive intervention.

Neuronavigation in minimally invasive spine surgery

OBJECT

Parallel advancements in image guidance technology and minimal access techniques continue to push the frontiers of minimally invasive spine surgery (MISS). While traditional intraoperative imaging remains widely used, newer platforms, such as 3D-fluoroscopy, cone-beam CT, and intraoperative CT/MRI, have enabled safer, more accurate instrumentation placement with less radiation exposure to the surgeon. The goal of this work is to provide a review of the current uses of advanced image guidance in MISS.

METHODS

The authors searched PubMed for relevant articles concerning MISS, with particular attention to the use of image-guidance platforms. Pertinent studies published in English were further compiled and characterized into relevant analyses of MISS of the cervical, thoracic, and lumbosacral regions.

RESULTS

Fifty-two studies were included for review. These describe the use of the iso-C system for 3D navigation during C1-2 transarticular screw placement, the use of endoscopic techniques in the cervical spine, and the role of navigation guidance at the occipital-cervical junction. The authors discuss the evolving literature concerning neuronavigation during pedicle screw placement in the thoracic and lumbar spine in the setting of infection, trauma, and deformity surgery and review the use of image guidance in transsacral approaches.

CONCLUSIONS

Refinements in image-guidance technologies and minimal access techniques have converged on spinal pathology, affording patients the ability to undergo safe, accurate operations without the associated morbidities of conventional approaches. While percutaneous transpedicular screw placement is among the most common procedures to benefit from navigation, other areas of spine surgery can benefit from advances in neuronavigation and further growth in the field of image-guided MISS is anticipated.

Prevertebral vascular and esophageal consideration during percutaneous cervical disc procedures

STUDY DESIGN

A retrospective review series.

OBJECTIVE

To identify vascular anatomy and esophageal deviations that may interfere with a percutaneous anterior approach in cervical spine surgery.

SUMMARY OF BACKGROUND DATA

The percutaneous anterior approach has been used for minimally invasive interventions of cervical disc diseases. Although the percutaneous anterior approach is frequently performed, reports of obstructing anatomical structures and procedural risks are limited.

METHODS

Cervical magnetic resonance images obtained from December 2012 to April 2013 from a total of 511 patients at Guro Teun Teun Hospital were evaluated in this study. Each axial T2-weighted MR image from the disc levels of C3-C4 to C6-C7 (total, 3066 images) was reviewed to check for the presence of small vessels along the trajectories of percutaneous cervical procedures on the left and right sides. Esophageal deviation was also measured at level C6-C7.

RESULTS

Small vessels in the anterior neck were present, respectively, in 50.5% (trajectory on the left side) and in 49.1% (trajectory on the right side) at disc level C3-C4, in 30.3% and 28.8% at C4-C5, in 24.1% and 7.6% at C5-C6, and in 55.2% and 43.1% at C6-C7. There were no differences in the number of small vessels between the left and right sides at the upper cervical level (C3-C4-C5), but small vessels were less frequently observed on the right side at lower cervical levels (C5-C6-C7). Differences in esophageal deviation were also observed, with less deviation to the right side (0.63 ± 0.35 cm) than the left (1.18 ± 0.52 cm). As well, an esophageal diverticulum was observed in 1 case on the left side.

CONCLUSION

Although surgical approaches are mostly concerned with the location of pathology to be removed, a right-sided percutaneous approach seems preferable because poses less of a risk of encountering small vessels and causing esophageal injury.

LEVEL OF EVIDENCE

4.

Endoscopic transforaminal thoracic foraminotomy and discectomy for the treatment of thoracic disc herniation

Thoracic disc herniation is a relatively rare yet challenging-to-diagnose condition. Currently there is no universally accepted optimal surgical treatment for symptomatic thoracic disc herniation. Previously reported surgical approaches are often associated with high complication rates. Here we describe our minimally invasive technique of removing thoracic disc herniation, and report the primary results of a series of cases. Between January 2009 and March 2012, 13 patients with symptomatic thoracic disc herniation were treated with endoscopic thoracic foraminotomy and discectomy under local anesthesia. A bone shaver was used to undercut the facet and rib head for foraminotomy. Discectomy was achieved by using grasper, radiofrequency, and the Holmium-YAG laser. We analyzed the clinical outcomes of the patients using the visual analogue scale (VAS), MacNab classification, and Oswestry disability index (ODI). At the final follow up (mean: 17 months; range: 6–41 months), patient self-reported satisfactory rate was 76.9%. The mean VAS for mid back pain was improved from 9.1 to 4.2, and the mean ODI was improved from 61.0 to 43.8. One complication of postoperative spinal headache occurred during the surgery and the patient was successfully treated with epidural blood patch. No other complications were observed or reported during and after the surgery.

Deuk Laser Disc Repair(®) is a safe and effective treatment for symptomatic cervical disc disease

BACKGROUND

Deuk Laser Disc Repair(®) is a new full-endoscopic surgical procedure to repair symptomatic cervical disc disease.

METHODS

A prospective cohort of 66 consecutive patients underwent cervical Deuk Laser Disc Repair(®) for one (n = 21) or two adjacent (n = 45) symptomatic levels of cervical disc disease and were evaluated postoperatively for resolution of headache, neck pain, arm pain, and radicular symptoms. All patients were candidates for anterior cervical discectomy and fusion (ACDF) or arthroplasty. The Mann-Whitney Wilcoxon test was used to calculate P values.

RESULTS

All patients (n = 66) had significant improvement in preoperative symptoms with an average symptom resolution of 94.6%. Fifty percent (n = 33) had 100% resolution of all preoperative cervicogenic symptoms. Only 4.5% (n = 3) had less than 80% resolution of preoperative symptoms. Visual analog scale (VAS) significantly improved from 8.7 preoperatively to 0.5 postoperatively (P < 0.001) for the cohort. Average operative and recovery times were 57 and 52 minutes, respectively. There were no perioperative complications. Recurrent disc herniation occurred in one patient (1.5%). Average postoperative follow-up was 94 days and no significant intergroup difference in outcomes was observed (P = 0.111) in patients with <90 days (n = 52) or >90 days (n = 14, mean 319 days) follow-up. No significant difference in outcomes was observed (P = 0.774) for patients undergoing one or two level Deuk Laser Disc Repair(®). Patients diagnosed with postoperative cervical facet syndrome did significantly worse (P < 0.001).

CONCLUSION

Deuk Laser Disc Repair(®) is a safe and effective alternative to ACDF or arthroplasty for the treatment of one or two adjacent symptomatic cervical disc herniations with an overall success rate of 94.6%.

A meta-analysis comparing the results of cervical disc arthroplasty with anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic cervical disc disease

BACKGROUND

Anterior cervical discectomy and fusion is a standard treatment for symptomatic cervical disc disease, but pseudarthrosis and accelerated adjacent-level disc degeneration may develop. Cervical disc arthroplasty was developed to preserve the kinematics of the functional spinal unit. Trials comparing arthroplasty with anterior cervical discectomy and fusion have shown unclear benefits in terms of clinical results, neck motion at the operated level, adverse events, and the need for secondary surgical procedures.

METHODS

Only randomized clinical trials were included in this meta-analysis, and the search strategy followed the requirements of the Cochrane Library Handbook. Two reviewers independently assessed the methodological quality of each included study and extracted the relevant data.

RESULTS

Twenty-seven randomized clinical trials were included; twelve studies were Level I and fifteen were Level II. The results of the meta-analysis indicated longer operative times, more blood loss, lower neck and arm pain scores reported on a visual analog scale, better neurological success, greater motion at the operated level, fewer secondary surgical procedures, and fewer such procedures that involved supplemental fixation or revision in the arthroplasty group compared with the anterior cervical discectomy and fusion group. These differences were significant (p < 0.05). The two groups had similar lengths of hospital stay, Neck Disability Index scores, and rates of adverse events, removals, and reoperations (p > 0.05).

CONCLUSIONS

The meta-analysis revealed that anterior cervical discectomy and fusion was associated with shorter operative times and less blood loss compared with arthroplasty. Other outcomes after arthroplasty (length of hospital stay, clinical indices, range of motion at the operated level, adverse events, and secondary surgical procedures) were superior or equivalent to the outcomes after anterior cervical discectomy and fusion.

Full-endoscopic interlaminar approach for the surgical treatment of lumbar disc herniation: the causes and prophylaxis of conversion to open

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To analyze the causes of conversion to open for the surgical treatment of lumbar disc herniation with use of full endoscopic (FE) technique, and prophylaxis of conversion to open also proposed.

METHOD

50 patients with lumbar disc herniation underwent discectomy using unilateral portal FE interlaminar approach collected from August 2008 to August 2010. All FE operations were performed under general anesthesia and endotracheal intubation. According to the level incision of the ligament flavum, the starting point of nerve root at the dura under endoscopic view was classified as: Type I (starting point of the nerve root was higher than the incision) and Type II (the starting point of nerve root was lower than the incision). The causes and effective prophylactic measurements for cases of conversion to open were analyzed.

RESULTS

There were 47 cases classified as Type I for a rate of 94 %, and Type II in 3 cases for a rate of 6 %. Five cases were converted to open surgery, and the conversion rate was 10 %. There were three males and two females with a mean age of 36.2 (29-44) years, the average duration of symptoms was 58.4 (35-105) days. The level was L5-S1 in four cases and L4-5 in one, lateral extrusion in three cases, paracentral extrusion in one, and sequestration in one. Leg pain resolved in three cases and improved in two after open surgery. Of five cases of conversion to open, misplacement of the working portal occurred in one case (Type I). Difficult dissection of nerve root and hemostasis resulting in open conversion occurred in one case (Type II); this patient sustained a dural injury. The nerve root could not be exposed in three cases (Type II), the FE changed to open finally. During the open procedure with Type II, we found that the location of origin of the nerve root was caudal to the inferior laminar edge. Therefore, partial removal of bony structures along lateral recess was necessary in order to visualize the nerve root.

CONCLUSION

Misplacement of working portal during the exposure of the ligament flavum and difficulty in indentifying anatomy are potential causes for conversion to open in the initial adoption of FE technique. However, uncommon conditions such as variation of the nerve root origin can also result in conversion to open in experienced hands. Endoscopic experience, proper patient selection and specific radiographic examination are needed to obtain optimal outcomes using a full endoscopic technique for microdiscectomies.

Retaining intradiscal pressure after annulotomy by different annular suture techniques, and their biomechanical evaluations

BACKGROUND

The adverse effects of annulotomy during lumbar discectomy have been increasingly recognized, and methods are developing to repair the annular defect. Biomechanically, the repair should retain the intra-nuclear pressure, which is doubtful using the current suture techniques. Therefore, a new suture technique was designed and tested to close a simpler type of annular incision.

METHODS

A new suture technique, the modified purse-string suture, was introduced into a re-validated nonlinear finite element human disk model after creating a standard transverse slit incision, as well as two other suture techniques: either two simple sutures, or a horizontal crossed suture, and compared their contact pressure on the cleft contact surface. Then, porcine lumbar endplate-disk-endplate complexes with transverse slit incisions were repaired using the three techniques. Quantitative discomanometry was then applied to compare their leakage pressure, as a parameter of disk integrity.

FINDINGS

In finite element model, the new technique created the greatest contact pressure along the suture range (the outer annulus), and generated a minimum contact pressure at the critical point, which was 68% and 55% higher than the other two suture techniques. In quantitative discomanometry, the new suture technique also had an average leakage pressure of 85% and 49% higher than the other two suture techniques.

INTERPRETATION

The modified purse-string suture can generate higher contact pressure than the other two techniques at finite element analysis and in realistic animal models, which aids in retaining intra-discal pressure, and should be encouraged in clinical practice.

Systematic review of anterior interbody fusion techniques for single- and double-level cervical degenerative disc disease

STUDY DESIGN

A systematic review of randomized controlled trials.

OBJECTIVE

To determine which technique of anterior cervical interbody fusion (ACIF) gives the best outcome in patients with cervical degenerative disc disease.

SUMMARY OF BACKGROUND DATA

The number of surgical techniques for decompression and ACIF as treatment for cervical degenerative disc disease has increased rapidly, but the rationale for the choice between different techniques remains unclear.

METHODS

From a comprehensive search, we selected randomized studies that compared anterior cervical decompression and ACIF techniques, in patients with chronic single- or double-level degenerative disc disease or disc herniation. Risk of bias was assessed using the criteria of the Cochrane back review group.

RESULTS

Thirty-three studies with 2267 patients were included. The major treatments were discectomy alone and addition of an ACIF procedure (graft, cement, cage, and plates). At best, there was very low-quality evidence of little or no difference in pain relief between the techniques. We found moderate quality evidence for few secondary outcomes. Odom's criteria were not different between iliac crest autograft and a metal cage (risk ratio [RR]: 1.11; 95% confidence interval [CI]: 0.99-1.24). Bone graft produced more fusion than discectomy (RR: 0.22; 95% CI: 0.17-0.48). Complication rates were not different between discectomy and iliac crest autograft (RR: 1.56; 95% CI: 0.71-3.43). Low-quality evidence was found that iliac crest autograft results in better fusion than a cage (RR: 1.87; 95% CI: 1.10-3.17); but more complications (RR: 0.33; 95% CI: 0.12-0.92).

CONCLUSION

When fusion of the motion segment is considered to be the working mechanism for pain relief and functional improvement, iliac crest autograft appears to be the golden standard. When ignoring fusion rates and looking at complication rates, a cage as a golden standard has a weak evidence base over iliac crest autograft, but not over discectomy.

Single or double-level anterior interbody fusion techniques for cervical degenerative disc disease

BACKGROUND

The number of surgical techniques for decompression and solid interbody fusion as treatment for cervical spondylosis has increased rapidly, but the rationale for the choice between different techniques remains unclear.

OBJECTIVES

To determine which technique of anterior interbody fusion gives the best clinical and radiological outcomes in patients with single- or double-level degenerative disc disease of the cervical spine.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2009, issue 1), MEDLINE (1966 to May 2009), EMBASE (1980 to May 2009), BIOSIS (2004 to May 2009), and references of selected articles.

SELECTION CRITERIA

Randomised comparative studies that compared anterior cervical decompression and interbody fusion techniques for participants with chronic degenerative disc disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias using the Cochrane Back Review Group criteria. Data on demographics, intervention details and outcome measures were extracted onto a pre-tested data extraction form.

MAIN RESULTS

Thirty-three small studies ( 2267 patients) compared different fusion techniques. The major treatments were discectomy alone, addition of an interbody fusion procedure (autograft, allograft, cement, or cage), and addition of anterior plates. Eight studies had a low risk of bias. Few studies reported on pain, therefore, at best, there was very low quality evidence of little or no difference in pain relief between the different techniques. We found moderate quality evidence for these secondary outcomes: no statistically significant difference in Odom's criteria between iliac crest autograft and a metal cage (6 studies, RR 1.11 (95% CI 0.99 to1.24)); bone graft produced more effective fusion than discectomy alone (5 studies, RR 0.22 (95% CI 0.17 to 0.48)); no statistically significant difference in complication rates between discectomy alone and iliac crest autograft (7 studies, RR 1.56 (95% CI 0.71 to 3.43)); and low quality evidence that iliac crest autograft results in better fusion than a cage (5 studies, RR 1.87 (95% CI 1.10 to 3.17)); but more complications (7 studies, RR 0.33 (95% CI 0.12 to 0.92)).

AUTHORS' CONCLUSIONS

When the working mechanism for pain relief and functional improvement is fusion of the motion segment, there is low quality evidence that iliac crest autograft appears to be the better technique. When ignoring fusion rates and looking at complication rates, a cage has a weak evidence base over iliac crest autograft, but not over discectomy alone. Future research should compare additional instrumentation such as screws, plates, and cages against discectomy with or without autograft.

Endoscopic minimally invasive neurosurgery: emerging techniques and expanding role through an extensive review of the literature and our own experience - part II: extraendoscopic neurosurgery

BACKGROUND/AIMS

The field of minimally invasive neurosurgery has grown dramatically especially in the last decades. This has been possible, in the most part, due to the advancements in technology especially in tools such as the endoscope. The contemporary classification scheme for endoscopic procedures needs to advance as well.

METHODS

The present classification scheme for neuroendoscopic procedures has become confusing because it mainly describes the use of the endoscope as an assisting device to the microscope. The authors propose an update to the current classification that reflects the independence of the endoscope as a tool in minimally invasive neurosurgery.

RESULTS

The proposed classification groups the procedures as 'intraendoscopic' neurosurgery or 'extraendoscopic' neurosurgery (XEN) in relation to the 'axis' of the endoscope. A review of the literature for the XEN group together with exemplary cases is presented.

CONCLUSION

We presented our proposed classification for the endoscope-only surgical procedures. The XEN group is expanded in this article.