Minimally invasive spinal surgery: a historical perspective

A Comprehensive Review of the Historical Description of Spine Surgery and Its Evolution

Major strides in the advancement of spine surgery came about in the 21st century. However, the extensive history of spine surgery can be traced back to long before this time. A clear description of the journey from a primitive yet accurate understanding of the human musculoskeletal system to today's modern aspects of spinal techniques is lacking. A narrative literature review was conducted to elucidate where spine surgery began and the techniques used that evolved over time. This review was conducted using PubMed and Google Scholar. Search terms used included "history of spine surgery," "evolution of spine surgery," "origins of spine surgery," "history of laminectomy," "history of spinal fusion," "history of lumbar interbody fusion," "minimally invasive spine surgery," and "navigation in spine surgery." We highlight the evolution of the basic understanding of anatomy and non-surgical and surgical techniques, including bracing, laminectomy, discectomy, and spinal fusion. The current evolution and integration of minimally invasive techniques, lumbar interbody fusion techniques, robotics, navigation, and motion preservation are discussed, as these are the major areas of focus for technological advancement. This review presents an overarching synopsis of the events that chronicle the progress made in spine surgery since its conception. The review uniquely contributes to the growing body of literature on the expansion of spine surgery and highlights major events in its history.

Intradiscal Gelified Ethanol Nucleolysis versus Endoscopic Surgery for Lumbar Disc Herniation Radiculopathy

The purpose of this study was to retrospectively compare efficacy and safety between intradiscal injection of a gelified ethanol product and tubular discectomy in the treatment of intervertebral disk herniation. A bi-central institutional database research identified forty (40) patients suffering from symptomatic contained disc herniation. Nucleolysis Group included 20 patients [mean 50.05 ± 9.27 years-of-age (male/female 14/6-70/30%)] and Surgery Group included 20 patients [mean 48.45 ± 14.53 years-of-age, (male/female 12/8-60/40%)]. Primary outcome was overall 12-month improvement over baseline in leg pain (NVS units). Procedural technical outcomes were recorded, and adverse events were evaluated at all follow-up intervals. CIRSE classification system was used for complications' reporting. Mean pre-operative pain score in Nucleolysis Group was 7.95 ± 0.94 reduced to 1.25 ± 1.11 at month 1 and 0.45 ± 0.75 NVS units at year 1. Mean pre-operative pain score in Surgery Group was 7.65 ± 1.13 reduced to 1.55 ± 1.79 at month 1 and 0.70 ± 1.38 NVS units at year 1. Pain decrease was statistically significant after both procedures (p < 0.001). There was no statistically significant difference between pain reduction in both groups (p = 0.347). The decrease differences of the pain effect upon general activities, sleeping, socializing, walking, and enjoying life in the follow-up period between the two groups were not statistically significant. No complications were noted in both groups. Results from the current study report that intradiscal injection of a gelified ethanol and tubular discectomy were equally effective on terms of efficacy and safety for the treatment of symptomatic lumbar intervertebral disc herniation regarding the 12-month mean leg pain improvement. Both achieved similar rapid significant clinical improvement persisting throughout follow-up period.

Comparison of Unilateral Biportal Endoscopic Discectomy with Other Surgical Technics: A Systemic Review of Indications and Outcomes of Unilateral Biportal Endoscopic Discectomy from the Current Literature

OBJECTIVE

Unilateral biportal endoscopic (UBE) spine surgery for spinal diseases has been increasing in popularity because of its favorable outcomes. The goal of this systemic review is to analyze the status of outcomes and complications in lumbar disc herniation during UBE discectomy.

METHODS

A comprehensive search of the PubMed, Embase, Web of Science, and OVID databases published until June 30, 2021, was performed. The outcomes of interest were indications, operative time, blood loss, hospital stay, complications, visual analog scale score, and Oswestry Disability Index.

RESULTS

Seven studies were included in our research. UBE surgery for lumbar stenosis was excluded. A total of 230 patients with lumbar disc herniation were enrolled in the 7 selected studies. The mean operative time was 74.4 minutes, and the mean length of hospital stay was 4.5 days. Mean incidence of complications reported in the 7 articles was 6.2%. UBE showed shorter hospital stays than did microdiscectomy, no significant differences of Oswestry Disability Index or visual analog scale scores, and good recovery rate among other discectomy techniques (microdiscectomy, full endoscopic transforaminal endoscopic lumbar discectomy, and interlaminar endoscopic lumbar discectomy) at 1 month follow-up.

CONCLUSIONS

Even with the small number of studies and reports analyzed, biases were the main limitation of this analysis; overall, the clinical outcomes and complication rates associated with UBE discectomy were relatively good. It is clear that UBE discectomy is a good treatment choice for lumbar disc herniation, but to prevent unique UBE surgery complications, a clear understanding of the surgical procedures and careful efforts to overcome the learning curve are necessary.

A Review of Minimally Invasive Techniques in Thoracolumbar Trauma

The development of endoscopy, microscopy, and image guidance system provided the impetus for the adoption of minimally invasive surgery (MIS) techniques in the management of spinal trauma patients. The underlying drive has been an attempt to achieve the functional and biomechanical goals inherent to trauma care but through MIS techniques. Broadly the MIS techniques for spinal trauma can be divided into two categories—fusion and nonfusion methods. Fusion methods include mini-open or keyhole approaches that allow for discectomy and/or corpectomy and cage reconstruction via an anterior/lateral/posterior operative corridor. The nonfusion methods primarily include percutaneous pedicle screw fixation, kyphoplasty, and vertebroplasty, all without placement of bone graft or other attempts at inducing arthrodesis. In this review article, we have stratified the MIS techniques based on the operative corridor used and briefly described the decision-making process, technical nuances, pros, and cons of each technique.

Laser Therapy in Lumbar Disc Surgery - A Narrative Review

Introduction: Low back pain is one of the most chronic debilitating conditions involving considerable loss of cash, work, and quality time. Lasers are utilized in different fields of drugs, providing unique advantages. They are useful and advantageous in treating lumbar disc disease. In this research, an attempt is made to examine the role and importance of different lasers in lumbar disc surgeries. Methods: We conducted studies about laser therapy in lumbar disc surgery. Our primary search began with reviewing English-language citations from PubMed and Scopus between 1990 and 2019 using the keywords: (laser therapy) OR (lumbar disc AND disc surgery). The initial search yielded 97 articles. However, about 49 articles were selected and used in the present study. Results: Based on the present study, it can be found that there are several methods of using lasers to treat lumbar disc surgery. These methods all have their strengths and weaknesses. Conclusion: The development of laser lumbar disc surgery can be very helpful due to the reduction of surgical risks and the length of the patients' hospital stay. However, the choice of method used for this type of surgery should be made according to the patient's condition and based on the opinion of the treating physician.

Posterior percutaneous endoscopic versus traditional surgery for cervical disc herniation: A protocol for systematic review and meta analysis

BACKGROUND

Posterior percutaneous endoscopic cervical diskectomy (P-PECD) can be used posterior microdiscectomy for cervical disc herniation. But only some small sample sizes of clinical studies have evaluated the efficacy and safety of P-PECD. This study aim to evaluated the efficacy and safety of P-PECD compared with traditional open surgery.

METHODS

We will search the following seven electronic databases from their initiation to the May 1, 2020: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM) and Wanfang database. All randomized controlled trials, non-randomized controlled trials and retrospective case controls that compared the efficacy and safety of P-PECD and traditional open surgery in the treatment of cervical disc herniation will be included. The pooled odds ratio with 95% credible intervals (CIs) was used for the dichotomous variables. The mean difference with 95% CIs was used for the continuous variables. All analyses were conducted by Comprehensive Meta Analysis 2.0. A 2-tailed P value < 0.05 is considered statistically significant.

RESULTS

The results of systematic review and meta-analysis will be submitted to a peer-reviewed journal.

CONCLUSION

Our study will provide clarity regarding for clinicians to choices best surgical approach for patients with cervical disc herniation. Any changes that need to be made during the process of this study will be explained in the final full-text publication.

PROTOCOL REGISTRATION NUMBER

CRD42020164011.

Two window-minimally invasive lumbar spine surgery (new approach) has a better post operative outcome and less soft tissue damage

Introduction

The purpose of this new approach is to develop a method that is less invasive as well as less traumatic and can provide a better exposure/view of the surgical field. Postoperatively, the patient has less pain, short hospital stay and less use of the postoperative pain control medications. As compared to other minimally invasive spine surgeries this approach results in less soft tissue damage, minimal muscle destruction, less retraction and better surgical outcome.

Methods

In this article authors focus on the new approach that has cost effective benefits as well as short recovery time postoperatively.

Results

Approach is applicable for severe spinal stenosis as compared to other Minimally Invasive Spine Surgery (MISS) techniques that are only applicable for the mild to moderate stenosis or degenerative processes. This plane is avascular plane so no or less bleeding is anticipated from this procedure.

Conclusion

The technique facilitates bilateral canal enlargement through unilateral approach and provides accessibility to the contralateral foramen for decompression with perfect exposure and allows instrumentation through the lateral window with no muscle destruction.

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Minimally Invasive Spine Surgery, Fusion, Two windows approach.

Primary Dural Closure in Minimally Invasive Spine Surgery Using an Extracorporeal Knot: Technical Note

BACKGROUND

Minimally invasive spine surgeries (MISS) are currently used for a wide variety of intradural spinal pathologies. Although MISS techniques have brought great benefits, primary dural closure can prove a challenge due to the narrow corridor of the tubular retractor systems.

OBJECTIVE

To present the surgical technique we developed for dural closure using an extracorporeal knot that is simple and reproducible.

METHODS

We describe the use of an extracorporeal knot for primary dural closure in MISS surgeries using standard instrumental. We illustrate this operative technique with figures and its application in a surgical case with images and demonstration video2.

RESULTS

Using our surgical technique, a watertight dural closure with separated knots was performed without specific instruments.

CONCLUSION

The use of extracorporeal knots facilitates primary dural closure in MISS surgeries.

Percutaneous Unilateral Biportal Endoscopic Spine Surgery Using a 30-Degree Arthroscope in Patients With Severe Lumbar Spinal Stenosis: A Technical Note

BACKGROUND

Unilateral biportal endoscopic surgery (UBESS) for severe lumbar central canal stenosis (LCCS) remains challenging.

OBJECTIVE

To describe the use of UBESS with a 30-degree arthroscope in patients with severe LCCS.

MATERIALS AND METHODS

Working and viewing portals were created in each unilateral paravertebral area at the target interlaminar level. After ensuring the visual field with a 30-degree arthroscope, effective tissue removal was possible through safe access to the bilateral hypertrophic yellow ligament with minimal osteotomy. The authors evaluated 58 patients and analyzed the clinical outcomes using the visual analog scale, Macnab criteria, and self-predicted walking distance.

RESULTS

The visual analog scale scores for low back and leg pains decreased from 7.1 to 1.9 and from 7.9 to 1.6, respectively, at 18 months after the procedure. According to the Macnab criteria, "excellent," "good," and "fair" results were obtained in 51.7%, 41.4%, and 6.9% subjects, respectively. Before surgery, the subjects could walk a mean of 305.8±468.1 m. After surgery, 43.1% of the patients could walk for >1 hour, whereas the remaining patients could walk 1521.8±1831.1 m.

CONCLUSION

UBESS using a 30-degree arthroscope can be an efficient and safe intervention in patients with severe LCCS.

Cauda equina syndrome in dogs - a review

A lesion of sacrococcygeal spinal nerve roots forming a structure that resembles a horse's tail results in the development of clinical entity identified as the cauda equina syndrome (CES). The disease can evolve slowly and symptomatology can be incomplete, but the fully developed CES is characterized by pain and altered sensation in the pelvic extremities, tail, perianogenital region, paresis or plegia of hind limbs, incontinence and impotence. Major causes of CES in dogs are degenerative changes of the lumbosacral vertebral column, haematoma, inflammation, neoplasm or trauma. The diagnosis is based on history, clinical presentation, neurological symptomatology, spinal röntgenography, computed tomography, and magnetic resonance imaging. In animals experiencing initial episodes of CES, conservative therapy can be attempted. But the only rational treatment of patients with severe neurological deficit is surgical decompression of the neural structures. The outcome depends on the underlying aetiology and the degree of sensory, motor and autonomic dysfunction. Canine and porcine experimental models mimicking the CES showed the involvement of intrinsic spinal cord structures. This points out the need for an early diagnosis followed by aggressive management before irreversible neuronal lesions develop. The search strategy involved the PubMed, Medline, Embase and ISI Web of Science from January 2000 to August 2017 using the terms 'cauda equina syndrome' and 'lumbosacral stenosis' in the English language literature; also references from selected papers were scanned and relevant articles included.

A Comparison of Percutaneous Endoscopic Lumbar Discectomy and Open Lumbar Microdiscectomy for Lumbar Disc Herniation in the Korean: A Meta-Analysis

Background

Among the surgical methods for lumbar disc herniation, open lumbar microdiscectomy is considered the gold standard. Recently, percutaneous endoscopic lumbar discectomy is also commonly performed for lumbar disc herniation for its various strong points.

Objectives

The present study aims to examine whether percutaneous endoscopic lumbar discectomy and open lumbar microdiscectomy show better results as surgical treatments for lumbar disc herniation in the Korean population.

Methods

In the present meta-analysis, papers on Korean patients who underwent open lumbar microdiscectomy and percutaneous endoscopic lumbar discectomy were searched, both of which are surgical methods to treat lumbar disc herniation. The papers from 1973, when percutaneous endoscopic lumbar discectomy was first introduced, to March 2018 were searched at the databases of MEDLINE, EMBASE, PubMed, and Cochrane Library.

Results

Seven papers with 1254 patients were selected. A comparison study revealed that percutaneous endoscopic lumbar discectomy had significantly better results than open lumbar microdiscectomy in the visual analogue pain scale at the final follow-up (leg: mean difference [MD]=-0.35; 95% confidence interval [CI]=-0.61, -0.09; p=0.009; back: MD=-0.79; 95% confidence interval [CI]=-1.42, -0.17; p=0.01), Oswestry Disability Index (MD=-2.12; 95% CI=-4.25, 0.01; p=0.05), operation time (MD=-23.06; 95% CI=-32.42, -13.70; p<0.00001), and hospital stay (MD=-4.64; 95% CI=-6.37, -2.90; p<0.00001). There were no statistical differences in the MacNab classification (odds ratio [OR]=1.02; 95% CI=0.71, 1.49; p=0.90), complication rate (OR=0.72; 95% CI=0.20, 2.62; p=0.62), recurrence rate (OR=0.83; 95% CI=0.50, 1.38; p=0.47), and reoperation rate (OR=1.45; 95% CI=0.89, 2.35; p=0.13).

Limitations

All 7 papers used for the meta-analysis were non-RCTs. Some differences (type of surgery (primary or revisional), treatment options before the operation, follow-up period, etc.) existed depending on the selected paper, and the sample size was small as well.

Conclusion

While percutaneous endoscopic lumbar discectomy showed better results than open lumbar microdiscectomy in some items, open lumbar microdiscectomy still showed good clinical results, and it is therefore reckoned that a randomized controlled trial with a large sample size would be required in the future to compare these two surgical methods.

Minimally invasive decompression in patients with degenerative spondylolisthesis associated with lumbar spinal stenosis. Report of a surgical series and review of the literature

We reported the results of minimally invasive spinal decompression (MISD) in patients with degenerative spondylolisthesis (DS) associated with lumbar spinal stenosis (LSS) and performed a literature review in order to evaluate the clinical and radiological outcomes, the complications and reoperation rate of MISD procedures in these patients. Data of 28 patients submitted to MISD for DS associated to LSS were reviewed. We evaluated the Visual Analogue Scale (VAS) both for low back pain (LBP) and legs pain, the Oswestry Disability Index (ODI) and the degree of the slippage. A PubMed search of the English literature was conducted. Only papers with more than 10 patients and reporting explicitly data of patients with DS were included in the analysis. We found a statistically significant improvement of LBP, legs pain and ODI in our series. The degree of slippage was stable at follow-up (FU) with no need of reoperation. No major complications occurred. In our literature review, we were able to analyze the differences in ODI in 156 patients and the differences in Japanese Orthopedic Association (JOA) score in 218 patients. We observed a statistically significant improvement of ODI and JOA score at FU compared to pre-operative. The percentage of slippage, evaluated in 283 patients, was unchanged at FU compared to pre-operative. The overall complication rate was 1.6%. The overall reoperation rate was 4.5%. MISD procedures are safe and effective in patients with DS associated to LSS and are associated to low morbidity and significant improvement of disability without progression of slippage.

Percutaneous endoscopic cervical discectomy: a technical review

The treatment of cervical disc herniations has evolved in the last 2 decades. While the anterior cervical discectomy and fusion continues being the gold standard for the treatment of radicular pain triggered by cervical disc herniation, other surgical approaches have been developed. Percutaneous endoscopic cervical discectomy has demonstrated the ability to decompress the exiting nerve root and dural sac correctly and encouraging clinical outcomes has been reported in the literature. One of the most important advantages offered by the endoscopic technique is the capability to resolve the patient's symptoms without the need for interbody fusion. Also, a specific and selective decompression under continuous visualization with minimal surgery-related trauma can be achieved. There are two percutaneous endoscopic cervical discectomy approaches: anterior and posterior. The decision to perform each other depends on pathology site. However, the endoscopic technique requires previous surgical training, a steep learning curve, and proper patient selection. The development of new hardware such as endoscopes with better optics, lighting systems, and endoscopic surgical tools have allowed using endoscopic techniques in more complex cases. The objective of this review is the technical description of the anterior and posterior percutaneous endoscopic cervical discectomy.

Endoscope-Assisted Abscess Drainage Secondary to Endoscope-Assisted Transforaminal Lumbar Interbody Fusion: 1-Year Follow-Up

INTRODUCTION

Endoscopic discectomy and fusions have been gaining popularity in the recent past and are noted to be safe for their application in elderly population. The procedure involves ultra-small incision for discectomy followed by placement of percutaneous screws in awake patients. Treatment of advanced spinal pathology with endoscope-assisted techniques is challenging. Although not common with the endoscopic approach, postoperative infection can be problematic, as there are no established guidelines on its management.

METHODS

A 76-year-old female patient underwent lumbar 4-5 endoscopic-assisted transforaminal lumbar interbody fusion for severe degenerative changes leading to back and radicular leg pain. She did well postoperatively and was discharged home the following day. She presented to the outside hospital with new onset of severe back pain, sepsis, and positive methicillin-susceptible Staphylococcus aureus with blood culture and demonstrated no improvement while on antibiotics.

RESULTS

Initial magnetic resonance imaging revealed postoperative changes only. With positive blood culture and localized pain, she was then offered to undergo a percutaneous drainage of the abscess. Under local anesthesia and intravenous sedation, a small pocket of collection was found along the endoscopic trajectory from previous surgery. After evacuation of the collection, the interbody device was irrigated with vancomycin through endoscope. Postoperatively, immediate symptomatic improvement was noted in back pain. She was discharged home on oxacillin and continues to do well at 12 months' follow-up with excellent fusion.

CONCLUSIONS

The present case illustrates the successful treatment of a surgical-site infection after endoscope-assisted transforaminal lumbar interbody fusion via a repeat percutaneous endoscopic approach.

Comparison of the Minimally Invasive and Conventional Open Surgery Approach in the Treatment of Lumbar Stenosis: A Systematic Review and a Meta-Analysis

Introduction: Minimally invasive surgery (MIS) is increasingly used in the treatment of lumbar stenosis. However, it is still not clear if the employment of minimally invasive surgical techniques can achieve superior clinical outcomes compared to standard open laminectomy. Materials and Methods: An extensive literature review regarding the clinical outcome, safety, and efficiency of MIS and standard open surgery (OS) in the treatment of lumbar stenosis was conducted on Medline, Cochrane, EMBASE, and Google Scholar databases up to 19 August 2016. Results: Sixteen studies that enrolled a total of 1580 patients with surgically-indicated lumbar stenosis were identified; 793 patients underwent MIS and 787 patients underwent conventional OS. No significant difference was found in the improvement of Oswestry Disability Index (ODI) (P = 0.718) and operation time (P = 0.322) between patients from different treatment groups. MIS was associated with better visual analogue scale (VAS) for back pain (P = 0.01), shorter length of hospital stay (P <0.001), and lower blood loss (P <0.001). Conclusion: Our findings indicate that both MIS and standard OS can effectively manage patients with lumbar stenosis and lead to comparable clinical outcomes. Further studies are necessary to evaluate MIS with different types of conventional surgery for lumbar stenosis. Key words: Back pain, Laminectomy

Against the odds: extraordinary recovery from complete cauda equina syndrome following L3 fracture. Time still matters

INTRODUCTION

Cauda equina syndrome secondary to lumbar fracture is a relative rare event. Although it is usually considered as an emergency, there is still controversy in the literature regarding the optimal timeframe of surgical intervention in complete spinal cord and cauda equina injuries.

CASE PRESENTATION

We report a case of a 24-year-old victim of a road traffic accident admitted with an L3 fracture causing complete cauda equina syndrome, who underwent early surgery within 12 h and made an extraordinary recovery (from AIS A to E).

DISCUSSION

Although the timing of surgery in complete traumatic spinal cord injury and cauda equina syndrome remains controversial, this case highlights the importance of early surgical intervention even in complete injuries.

Thoracoscopic Vertebrectomy for Thoracolumbar Junction Fractures and Tumors: Surgical Technique and Evaluation of the Learning Curve

STUDY DESIGN

Retrospective study.

OBJECTIVE

The authors evaluated the surgical technique and learning curve for video-assisted thoracoscopic surgery (VATS) for treating thoracolumbar junction burst fractures and bony tumors by examining surgical data and outcome for the first 30 VATS procedures performed by a single surgeon at a training institution.

SUMMARY OF BACKGROUND DATA

VATS is commonly used in the treatment of early-stage lung cancer. Widespread use of this technique among neurosurgeons is limited by the lack of cases and the steep learning curve.

METHODS

This study was a retrospective case series of the first 30 T12 and L1 thoracoscopic vertebrectomies from 2003 to 2008. The sample was limited to 1 surgeon and 1 region of the spine to minimize the potential variation so that a learning curve could be assessed. Surgical data and outcomes were analyzed. Estimated blood loss and operation time were analyzed using a linear generalized estimating equation model with a first-order autoregression correlation structure.

RESULTS

The average operative time for thoracoscopic corpectomy was 270±65 minutes (range, 160-416 min). Operating room time decreased significantly after the first 3 operations. The authors observed a stable linear decrease in operating time over the course of the study. The average blood loss during the thoracoscopic procedure was 433±330 mL (range, 100-1500 mL) and did not change as the series progressed. Complications and conversions to open procedures occurred in 2 patients and were evenly distributed throughout the series.

CONCLUSIONS

Thoracoscopic vertebrectomy at the thoracolumbar junction has a relatively long learning curve. In this series, operating room time improved dramatically after the first 3 cases but continued to improve subsequently. The learning curve can be accomplished without an increase in blood loss, complications, rate of conversion to open procedures, or frequency of misplaced instrumentation.

Lumbar microdiscectomy complication rates: a systematic review and meta-analysis

OBJECT Lumbar microdiscectomy and its various minimally invasive surgical techniques are seeing increasing popularity, but a systematic review of their associated complications has yet to be performed. The authors sought to identify all prospective clinical studies reporting complications associated with lumbar open microdiscectomy, microendoscopic discectomy (MED), and percutaneous microdiscectomy. METHODS The authors conducted MEDLINE, Scopus, Web of Science, and Embase database searches for randomized controlled trials and prospective cohort studies reporting complications associated with open, microendoscopic, or percutaneous lumbar microdiscectomy. Studies with fewer than 10 patients and published before 1990 were excluded. Overall and interstudy median complication rates were calculated for each surgical technique. The authors also performed a meta-analysis of the reported complications to assess statistical significance across the various surgical techniques. RESULTS Of 9504 articles retrieved from the databases, 42 met inclusion criteria. Most studies screened were retrospective case series, limiting the number of studies that could be included. A total of 9 complication types were identified in the included studies, and these were analyzed across each of the surgical techniques. The rates of any complication across the included studies were 12.5%, 13.3%, and 10.8% for open, MED, and percutaneous microdiscectomy, respectively. New or worsening neurological deficit arose in 1.3%, 3.0%, and 1.6% of patients, while direct nerve root injury occurred at rates of 2.6%, 0.9%, and 1.1%, respectively. Hematoma was reported at rates of 0.5%, 1.2%, and 0.6%, respectively. Wound complications (infection, dehiscence, orseroma) occurred at rates of 2.1%, 1.2%, and 0.5%, respectively. The rates of recurrent disc complications were 4.4%, 3.1%, and 3.9%, while reoperation was indicated in 7.1%, 3.7%, and 10.2% of operations, respectively. Meta-analysis calculations revealed a statistically significant higher rate of intraoperative nerve root injury following percutaneous procedures relative to MED. No other significant differences were found. CONCLUSIONS This review highlights complication rates among various microdiscectomy techniques, which likely reflect real-world practice and conceptualization of complications among physicians. This investigation sets the framework for further discussions regarding microdiscectomy options and their associated complications during the informed consent process.

Comparison of percutaneous endoscopic lumbar discectomy versus open lumbar microdiscectomy for lumbar disc herniation: A meta-analysis

PURPOSE

The purpose of the study is to perform a systematic review and meta-analysis to evaluate the clinical results of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar microdiscectomy (OLM) for the treatment of lumbar disc herniation (LDH).

METHODS

Randomized controlled trials or non-randomized controlled trials published from the time when databases were built to March 2016 that compared the clinical effectiveness of PELD and OLM surgical approaches for the treatment of LDH were acquired by a comprehensive search in four electronic databases (PubMed, EMBASE, Web of Science and Cochrane library). A total of 7 studies (1389 patients) were included in this systematic review and meta-analysis. Pooled mean differences (MD) and odds ratios (OR) and with 95% CIs were calculated for the outcomes.

RESULT

The results showed that there were no statistically between the PELD group and OLM group in terms of preoperative VAS-BP score (WMD = 0.03; 95% CI: -0.99 to 1.05; P = 0.95), postoperative VAS-BP score (WMD = -0.56; 95% CI: -1.43 to 0.31; P = 0.21), postoperative ODI (WMD = -0.98; 95% CI: -4.96 to 3.00; P = 0.63), complication rate (OR = 1.79; 95% CI: 0.95 to 3.37; P = 0.07) or reoperation rate (OR = 1.44; 95% CI: 0.94 to 2.20; P = 0.09). PELD group was associated with shorter operation time (WMD = -12.83; 95% CI: -24.79 to -0.87; P = 0.04) and hospital stay (WMD = -5.49; 95% CI: -8.63 to -2.35; P = 0.0006).

CONCLUSION

The existing evidence indicate that no superiority exists between the two surgical approaches for the treatment of LDH in terms of functional outcome, complication rate and reoperation rate, in spite of that PELD surgical group can achieve shorter operation time and hospital stay than OLM surgical group.

Percutaneous Fully Endoscopic İnterlaminar Approach to the Filum Terminale: A Cadaveric Study

OBJECTIVE

To investigate the utility, safety, and feasibility of a novel endoscopic technique for the visualization and surgical manipulation of the filum terminale in fresh postmortem adult human cadavers.

METHODS

The filums from 18 fresh postmortem adult human cadavers were explored with a percutaneous fully endoscopic interlaminar approach. After the filum was identified and the nerve roots were dissected away from it, the filum was cut. A specimen was sent for histopathologic examination.

RESULTS

In 15 of 18 (83%) cadavers, the filum terminale could be visualized. A specimen for histopathologic examination was obtained from 11 of 15 (73%) visualized filums. Histopathologic examination revealed that 2 of them were fatty filums, 7 were normal filums, and 2 were peripheral nerves.

CONCLUSIONS

We have described a successful and feasible percutaneous fully endoscopic interlaminar approach to the filum terminale. This technique provides a smaller skin incision, narrow durotomy, and minimal tissue damage. Animal studies are necessary to prove the feasibility and safety of our method before clinical use.

Missed Cauda Equina Syndrome after Burst Fracture of the Lumbar Spine

Cauda equina syndrome (CES) is often defined as a complex of symptoms and signs consisting of low back pain, bilateral sciatica, lower extremity weakness, saddle anesthesia, and bowel and bladder dysfunction. CES is considered to be neurosurgical emergency. Delayed or missed diagnosis of CES can result in serious morbidity and neurological sequelae. However, the diagnosis of CES is often difficult when one or more of these symptoms are absent or when these symptoms develop asymmetrically or incompletely. We report a case of urinary retention and sphincter dysfunction without sciatica or motor weakness following an L3 burst fracture in a 52-year-old male and discuss the atypical presentation of CES and treatment of traumatic CES.

Reduction and retention of thoracolumbar fractures by minimally invasive stabilisation versus open posterior instrumentation

PURPOSE

The purpose of this study was in thoracolumbar fractures to assess the effectiveness of minimal invasive stabilisation compared to the open technique with regards to the change in kyphosis angle, the loss of reduction and length of hospital stay.

METHODS

The retrospective study consisted of 104 patients who received minimally invasive stabilisation or open stabilisation. Patients were between 15 and 86 years of age, had a thoracolumbar fracture and no neurological deficits. Kyphotic angle (Cobb angle) and loss of reduction was compared after minimal invasive and open stabilisation. The Cobb angle was evaluated directly post operatively, at 6 weeks, 3 months, 6 months and 12 months after surgery.

RESULTS

Evaluated patients who received the minimally invasive technique had a shorter surgical intervention time and a shorter hospital stay compared to patients who received the open technique. Kyphosis angle and loss of reduction showed no significant difference compared to open technique. There was also no significant difference between minimally invasive poly-axial and mono-axial stabilisation.

CONCLUSION

In this study we provide evidence that MIS instrumentation in selected thoracolumbar fractures can effectively be used without significant differences in loss of reduction compared to open stabilisation. MIS can also sufficiently retain reduction as compared to traditional open techniques. The main advantages are reduced operation time and shorter hospital stay.

Instrumentation of the posterior thoracolumbar spine: from wires to pedicle screws

Over the past 120 years, spinal stabilization has advanced immensely. An updated review highlighting these advancements has not been performed in the past 20 years. The objective of this report is to provide a historical assessment of the decades outlining various key innovators, their techniques, and instrumentation. It is important to provide new generations of surgeons and students with historical evidence of the value of developing new techniques and instrumentation to improve patient care and outcomes.

Mast Quadrant-assisted minimally invasive modified transforaminal lumbar interbody fusion: single incision versus double incision

BACKGROUND

The concept of minimally invasive techniques is to make every effort to reduce tissue damage. Certainly, reducing skin incision is an important part of these techniques. This study aimed to investigate the clinical feasibility of Mast Quadrant-assisted modified transforaminal lumbar interbody fusion (TLIF) with a small single posterior median incision.

METHODS

During the period of March 2011 to March 2012, 34 patients with single-segment degenerative lumbar disease underwent the minimally invasive modified TLIF assisted by Mast Quadrant with a small single posterior median incision (single incision group). The cases in this group were compared to 37 patients with single-segment degenerative lumbar disease in the double incision group. The perioperative conditions of patients in these two groups were statistically analyzed and compared. The Oswestry Disability Index (ODI) scores, Visual Analog Scale (VAS) scores, and sacrospinalis muscle damage evaluation indicators before operation and 3, 12 months postoperation were compared.

RESULTS

A total of 31 and 35 cases in the single incision and double incision groups, respectively, completed at least 12 months of systemic follow-up. The differences in perioperative conditions between the two groups were not statistically significant. The incision length of the single incision group was significantly shorter than that of the double incision group (P < 0.01). The ODI and VAS scores of patients in both groups improved significantly at 3 and 12 months postoperation. However, these two indicators at 3 and 12 months postoperation and the sacrospinalis muscle damage evaluation indicators at 3 months postoperation did not differ significantly between the two groups (P ≥ 0.05).

CONCLUSIONS

Mast Quadrant-assisted modified TLIF with a small single posterior median incision has excellent clinical feasibility compared to minimally invasive TLIF with a double paramedian incision.

Outcomes after decompressive laminectomy for lumbar spinal stenosis: comparison between minimally invasive unilateral laminectomy for bilateral decompression and open laminectomy: clinical article

OBJECT

The development of minimally invasive surgical techniques is driven by the quest for better patient outcomes. There is some evidence for the use of minimally invasive surgery for degenerative lumbar spine stenosis (LSS), but there are currently no studies comparing outcomes with matched controls. The object of this study was to compare outcomes following minimally invasive unilateral laminectomy for bilateral decompression (ULBD) to a standard "open" laminectomy for LSS.

METHODS

The authors conducted a prospective, 1:1 randomized trial comparing ULBD to open laminectomy for degenerative LSS. The study enrolled 79 patients between 2007 and 2009, and adequate data for analysis were available in 54 patients (27 in each arm of the study). Patient demographic characteristics and clinical characteristics were recorded and clinical outcomes were obtained using pre- and postoperative Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores for leg pain, patient satisfaction index scores, and postoperative 12-Item Short Form Health Survey (SF-12) scores.

RESULTS

Significant improvements were observed in ODI and VAS scores for both open and ULBD interventions (p < 0.001 for both groups using either score). In addition, the ULBD-treated patients had a significantly better mean improvement in the VAS scores (p = 0.013) but not the ODI scores (p = 0.055) compared with patients in the open-surgery group. ULBD-treated patients had a significantly shorter length of postoperative hospital stay (55.1 vs. 100.8 hours, p = 0.0041) and time to mobilization (15.6 vs. 33.3 hours, p < 0.001) and were more likely to not use opioids for postoperative pain (51.9% vs. 15.4%, p = 0.046).

CONCLUSIONS

Based on short-term follow-up, microscopic ULBD is as effective as open decompression in improving function (ODI score), with the additional benefits of a significantly greater decrease in pain (VAS score), postoperative recovery time, time to mobilization, and opioid use.

The technological development of minimally invasive spine surgery

Minimally invasive spine surgery has its roots in the mid-twentieth century with a few surgeons and a few techniques, but it has now developed into a large field of progressive spinal surgery. A wide range of techniques are now called "minimally invasive," and case reports are submitted constantly with new "minimally invasive" approaches to spinal pathology. As minimally invasive spine surgery has become more mainstream over the past ten years, in this paper we discuss its history and development.

A prospective study of the incidence and outcomes of incidental dural tears in microendoscopic lumbar decompressive surgery

Little information is available about the incidence and outcome of incidental dural tears associated with microendoscopic lumbar decompressive surgery. We prospectively examined the incidence of dural tears and their influence on the outcome six months post-operatively in 555 consecutive patients (mean age 47.4 years (13 to 89)) who underwent this form of surgery. The incidence of dural tears was 5.05% (28/555). The risk factors were the age of the patient and the procedure of bilateral decompression via a unilateral approach. The rate of recovery of the Japanese Orthopaedic Association score in patients with dural tears was significantly lower than that in those without a tear (77.7% vs 87.6%; p < 0.02), although there were no significant differences in the improvement of the Oswestry Disability Index between the two groups. Most dural tears were small, managed by taking adequate care of symptoms of low cerebrospinal fluid pressure, and did not require direct dural repair. Routine MRI scans were undertaken six months post-operatively; four patients with a dural tear had recurrent or residual disc herniation and two had further stenosis, possibly because the dural tear prevented adequate decompression and removal of the fragments of disc during surgery; as yet, none of these patients have undergone further surgery.

Cite this article: Bone Joint J 2014;96-B:641–5.

The past, present and future of minimally invasive spine surgery: a review and speculative outlook

In the last 25 years of spinal surgery, tremendous improvements have been made. The development of smart technologies with the overall aim of reducing surgical trauma has resulted in the concept of minimally invasive surgical techniques. Enhancements in microsurgery, endoscopy and various percutaneous techniques, as well as improvement of implant materials, have proven to be milestones. The advancement of training of spine surgeons and the integration of image guidance with precise intraoperative imaging, computer- and robot-assisted treatment modalities constitute the era of reducing treatment morbidity in spinal surgery. This progress has led to the present era of preserving spinal function. The promise of the continuing evolution of spinal surgery, the era of restoring spinal function, already appears on the horizon. The current state of minimally invasive spine surgery is the result of a long-lasting and consecutive development of smart technologies, along with stringent surgical training practices and the improvement of instruments and techniques. However, much effort in research and development is still mandatory to establish, maintain and evolve minimally invasive spine surgery. The education and training of the next generation of highly specialized spine surgeons is another key point. This paper will give an overview of surgical techniques and methods of the past 25 years, examine what is in place today, and suggest a projection for spine surgery in the coming 25 years by drawing a connection from the past to the future.

Less invasive approaches for the treatment of cervical schwannomas: our experience

PURPOSE

The purpose of our paper is to illustrate our experience with minimally invasive approaches for the treatment of cervical schwannomas. Moreover, a brief review of the literature was conducted.

METHODS

All data regarding patients treated for cervical schwannomas were retrospectively revised. Site, size and extension of the lesions and preoperative neurological status were obtained through re-examination of neuroimaging and clinical records. Postoperative clinical examinations and radiological images were available for all patients. The clinical course was documented using the visual analog scale (VAS), Karnofsky score (KPS) and the Klekamp-Samii score system.

RESULTS

Sixteen patients harboring cervical schwannomas were treated from 2003 to 2009. Hemilaminectomy was performed in eight cases, subtotal hemilaminectomy in four cases, interlaminar fenestration in two cases, osteoplastic hemilaminotomy and laminoplasty in one case each. Postoperative neuroimaging revealed complete removal of the lesion and no signs of spinal instability. At discharge, neurological improvement was observed in 14 patients and all patients demonstrated reduction of VAS score and improvement of KPS and Klekamp-Samii's score.

CONCLUSIONS

Minimal access procedures are increasingly gaining popularity but their use is poorly described in the treatment of cervical tumors. Less invasive approaches may effectively be used instead of traditional laminectomy in the treatment of cervical tumors, especially schwannomas, providing less iatrogenic traumatism and preventing postsurgical spinal instability. Modern neuroimaging allows adequate preoperative planning and microsurgical techniques provide adequate execution of the surgical act. The procedure has to be tailored case by case considering the specific lesional features and the individual anatomical situation.

Complications and outcomes after spinal deformity surgery in the elderly: review of the existing literature and future directions

Object

The elderly population (age > 60 years) is the fastest-growing age group in the US. Spinal deformity is a major problem affecting the elderly and, therefore, the demand for surgery for spinal deformity is becoming increasingly prevalent in elderly patients. Much of the literature on surgery for adult deformity focuses on patients who are younger than 60 years, and therefore there is limited information about the complications and outcomes of surgery in the elderly population.

In this study, the authors undertook a review of the literature on spinal deformity surgery in patients older than 60 years. The authors discuss their analysis with a focus on outcomes, complications, discrepancies between individual studies, and strategies for complication avoidance.

Methods

A systematic review of the MEDLINE and PubMed databases was performed to identify articles published from 1950 to the present using the following key words: “adult scoliosis surgery” and “adult spine deformity surgery.” Exclusion criteria included patient age younger than 60 years. Data on major Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores, patient-reported outcomes, and complications were recorded.

Results

Twenty-two articles were obtained and are included in this review. The mean age was 74.2 years, and the mean follow-up period was 3 years. The mean preoperative ODI was 48.6, and the mean postoperative reduction in ODI was 24.1. The mean preoperative VAS score was 7.7 with a mean postoperative decrease of 5.2. There were 311 reported complications for 815 patients (38%) and 5 deaths for 659 patients (< 1%).

Conclusions

Elderly patient outcomes were inconsistent in the published studies. Overall, most elderly patients obtained favorable outcomes with low operative mortality following surgery for adult spinal deformity.

Use of a quantitative pedicle screw accuracy system to assess new technology: Initial studies on O-arm navigation and its effect on the learning curve of percutaneous pedicle screw insertion

Background

A quantitative screw accuracy system is proposed that allows for high-fidelity discrimination between various methods of pedicle screw insertion. Our purpose was to study the utility of a quantitative screw accuracy scoring system to assess new imaging technologies and their effects on the minimally invasive spine learning curve.

Methods

By use of a hypothetical “perfect screw,” a scoring system is proposed that may be used to compare the position of a small number of screws inserted according to a desired optimal position. This study incorporates a retrospective review of imaging studies for 10 patients who underwent percutaneous pedicle screw placement with either navigation-assisted O-arm imaging or navigation-assisted C-arm imaging. For the learning-curve portion of the study, 2 cadaveric adult torsos were used for instrumentation. Computed tomography imaging studies were used in both studies to assess screw position in the pedicle and vertebral body in relation to an optimal screw by use of a quantitative scoring system to rate accuracy.

Results

The quantitative scoring system allowed a statistically significant accuracy difference to be ascertained between 2 different technologies using fewer data points than previously published methods. When this screw scoring system is applied to minimally invasive percutaneous pedicle screw insertion, an optimal screw position can be achieved with greater accuracy through navigation-assisted technology (O-arm with computer-assisted navigation). When the O-arm with computer-assisted navigation was used by a novice surgeon learning the technique of percutaneous screw insertion, screws were inserted in a shorter period without loss of accuracy. In contrast, use of the traditional C-arm fluoroscopy leads to a loss of accuracy with faster insertion times. Increased accuracy can be seen clinically when compared with fluoroscopic navigation.

Conclusions

The use of a quantitative scoring system allows for rapid assessment of screw accuracy. As additional technologies and new teaching techniques for pedicle screw insertion are developed, this scoring system may be useful as an early assessment tool.

Percutaneous instrumentation of the cervical and cervico-thoracic spine using pedicle screws: preliminary clinical results and analysis of accuracy

The pedicle screw instrumentation represents the most rigid construct of the cervical and cervicothoracic spine and in spite of the risks to neurovascular structures clinical relevant complications do not occur frequently. The steep angles of the cervical pedicles result in a wide surgical exposure with extensive muscular trauma. The objective of this study was the evaluation of the accuracy of cervical pedicle screw insertion through a minimally invasive technique to reduce access-related muscular trauma. Therefore, percutaneous transpedicular instrumentation of the cervical and cervicothoracic spine was performed in 15 patients using fluoroscopy. All instrumentations from C2 to Th4 were inserted bilaterally through 2 to 3-cm skin and fascia incisions even in multilevel procedures and the rods were placed by blunt insertion through the incision. Thin-cut CT scan was used postoperatively to analyze pedicle violations. 76.4% of 72 screws were placed accurately. Most pedicle perforations were seen laterally towards the vertebral artery. Critical breaches >2 mm or narrowing of the transversal foramen occurred in 12.5% of screws; however, no revision surgery for screw displacement was needed in the absence of clinical symptoms. No conversion from percutaneous to open surgery was necessary. It was concluded that percutaneous transpedicular instrumentation of the cervical spine is a surgically demanding technique and should be reserved for experienced spine surgeons. The indications are limited to instrumentation-only procedures or in combination with anterior treatment, but with the potential to minimize access-related morbidity.

Arthroscopic techniques in minimally invasive spine surgery: closure of the lumbar fascia: surgical technique

BACKGROUND

The constrained working area in minimally invasive exposures of the spine may limit the capacity to effectively close the lumbar fascia, especially in patients with elevated body mass indexes. The working channel in these cases may have a diameter as narrow as 14 mm and a length up to 9 cm. Under these circumstances, the use of a conventional needle driver and a curved needle becomes suboptimal for closures of the fascia.

OBJECTIVE

To demonstrate the utility of an arthroscopic suture passer for closure of the lumbar fascia in such approaches.

METHODS

A flexible suture passer, typically used in arthroscopic rotator cuff repair surgery, was used through a minimally invasive portal for fascial closure after minimally invasive lumbar spine procedures.

RESULTS

The use of an arthroscopic suture passer precludes the need for rotation of a curved needle in a constrained working area. Deploying a nitinol needle through an arc delivers the suture through the fascia, thereby facilitating closure. Satisfactory lumbar fascia closures were achieved in 18 patients with elevated body mass indexes.

CONCLUSION

Application of existing technology in other surgical specialties may address the shortcomings of current techniques in minimally invasive approaches to the spine. The use of a flexible arthroscopic suture passer is one example in which current technology in one discipline may be applied to minimally invasive approaches. Increasing the awareness of techniques and instruments in other surgical disciplines may expand the armamentarium of the minimally invasive spine surgeon.

Microdiscectomia lombar tubular com o uso de seringas descartáveis de diâmetros progressivos: resultados cirúrgicos

OBJETIVO: descrever técnica minimamente invasiva para abordagem das hérnias discais com material de baixo custo. MÉTODOS: estudo prospectivo da avaliação dos resultados cirúrgicos de dez pacientes submetidos à microdiscectomia lombar tubular com uso de seringas descartáveis de diâmetros progressivos. RESULTADOS: utilizando os critérios de MacNab modificados, 60% dos pacientes apresentaram resultados considerados excelentes, 30% bons e 10% razoáveis. O tempo médio de cirurgia foi de 70 minutos e o de permanência hospitalar, de 14 horas. CONCLUSÃO: o uso de seringas descartáveis para microdiscectomia tubular foi seguro, de baixo custo e com resultados preliminares semelhantes aos da literatura para o tratamento minimamente invasivo da hérnia discal lombar.

Blood transfusions after thoracoscopic anterior thoracolumbar vertebrectomy

PURPOSE

Anterior vertebral body reconstruction (AVBR) for trauma or tumor involves corpectomy and placement of hardware to reconstitute the anterior weight-bearing stability of the spine. We report our clinical experience with thoracoscopic techniques for AVBR.

METHODS

We retrospectively analyzed patients who underwent thoracoscopic AVBR surgery for expandable cage placement. We report pathological condition, patient age, vertebral body level, operative time, estimated blood loss (EBL), and need for blood transfusion.

RESULTS

Twenty-one expandable cages were placed thoracoscopically in 15 fractures and six tumors. In fracture cases, mean age, operative time, EBL, and transfusion rate were 36.7 years, 4.9 h, 543 mL, and 7% (1/15), respectively. In tumor cases, mean age, operative time, EBL, and transfusion rate were 61.9 years, 4.9 h, 758 mL, and 17% (1/6), respectively.

CONCLUSIONS

Thoracoscopic AVBR with expandable cages can be accomplished safely with acceptable operative times and blood loss and low transfusion rates.

Approach-related morbidity in transthoracic anterior spine surgery: a clinical study and review of literature

BACKGROUND: Anterior access to the thoracic spine is done by open thoracotomy (OTC) or video-assisted thoracoscopic surgery (VATS). VATS is known as the method which results in lower morbidity rates, but there is little evidence of its less invasiveness. Objective: The current study yielded for outcome data concerning patients' perception of approach-related morbidity (ArM) following OTC for spinal surgery and that of a control group having a chest tube thoracotomy (CTT). METHODS: We performed a questionnaire assessment of ArM after OTC and CTT. Applying strict inclusion criteria, we compared outcomes in terms of percentage morbidity (Morbidity %) of 43 patients that underwent OTC for instrumented scoliosis correction to 30 patients that had CTT for minor thoracic pathologies (e.g., pneumothorax). RESULTS: Mean age in CTT and OTC Group was 50.2 and 16.5 years old, follow-up was of 32.2 and 58.4 months, and mean incision length was 2.5 and 25.5 cm, respectively. Mean number of levels fused in the OTC Group was 5.8. Mean morbidity (0% delineating no cases, 100% delineating highest morbidity) for the CTT Group was 10.8±15.4% (0-59.5%), 42% of patients had no morbidity. Signs of intercostal neuralgia (ICN) were present in 16.7%. A total of 35.5% had a morbidity >10% (mean: 27.5%), and 10% of morbidity cases were defined as having a chronic post-thoracotomy pain (CPP). In the OTC Group, mean morbidity was 7.0±12.7% (0-52.1%), 44% had no morbidity. Out of the sample, 18.6% had morbidity >10% (mean: 28.6%). Signs of ICN were present in 14%. In both groups, the presence of ICN had a significant impact on and showed correlation with morbidity (p<0.0001). In terms of clinical judgement, the severity of the ArM after a CTT or OTC was generally mild except for one patient in each group. Age and follow-up were significantly different between groups (p<0.0001, p=0.02), but the intergroup difference in morbidity was not significant (p=0.08). CONCLUSIONS: ArM after open thoracic spinal surgery or VATS procedures can be assessed using the questionnaire. To put ArM of OTC into perspective, a Control Group with simple CTT was selected, demonstrating that morbidity was not different between the OTC and CTT groups. Patients with increased signs of ICN do worse which was reflected by increased morbidity in both groups. The study demonstrates that not only the cosmesis is not a concern for patients undergoing OTC, but neither is the ArM a concern, equalling that of a simple CTT.

Percutaneous endoscopic cervical discectomy: 16 years of experience and literature review

The advancement of the percutaneous endoscopic lumbar discectomy (PECD) and its clinical success have led to similar minimally invasive approaches to the cervical spine. The goal of PECD is the decompression of the cervical nerve root through a direct endoscopic visualization, removing the herniated mass and shrinking the nucleous pulposus with the use of microforceps and holmium: yttrium-aluminum-garnet (Ho:YAG) laser. The senior author have performed PECD with cervical laser assisted endoscopy since 1993. The PECD is indicate to patients with constrained or unconstrained soft herniated cervical disc, positive provocative test, and no bony spur larger than 2 mm, regardless of the herniation size. The authors described the surgical technique of PECD and report their 16 years of experience in the endoscopic treatment of the herniated cervical disc.

Endoscopic spinal tethered cord release: operative technique

PURPOSE

This study aims to describe solely endoscopic surgical techniques for the treatment of spinal pathology. Here, we present a novel endoscopic technique for surgical untethering of the spinal cord by filum sectioning and discuss endoscopic surgical management of this entity.

METHODS

Two patients (ages 8 months and 10 years) presented with leg weakness, urine and bowel dysfunction, low back and neck pain, and thickened, fatty filum terminale. The elder patient presented with clinical incontinence and abnormal urodynamic studies.

RESULTS

Both patients underwent a solely endoscopic approach using 0 degrees and 30 degrees , 4 mm in diameter and 18 cm in length rigid endoscopes via a hemilaminectomy. Intradural microdissection under a direct visualization of endoscope delivered the fatty filum into the durotomy. Electrical stimulation was performed while the lower extremities and the anal sphincter were monitored for electromyographic activity. After acquisition of positive controls, the filum was identified by the lack of sphincter and lower extremity electromyographic responses and was then cauterized and cut. Both patients had significant improvement of their preoperative symptoms, and one patient had resolution of the abnormal urodynamics and her Chiari symptoms.

CONCLUSION

Tethered spinal cords can be safely and effectively untethered endoscopically. This procedure provides the advantages of reduced soft tissue injury, less postoperative pain, minimal blood loss, a smaller incision, and a shorter hospitalization. However, whether the endoscopic untethering technique achieves benefits above those associated with the open procedure remains to be determined by a control study.

Minimally invasive burst fracture fixation in the thoracolumbar region

Minimally invasive spine surgery is evolving rapidly. Compared with the traditional posterior approach with long and wide exposure, the minimally invasive approach offers significant advantages in treating patients with spine trauma.

Maximizing the potential of minimally invasive spine surgery in complex spinal disorders

Minimally invasive surgery (MIS) in the spine was primarily developed to reduce approach-related morbidity and to improve clinical outcomes compared with those following conventional open spine surgery. Over the past several years, minimally invasive spinal procedures have gained recognition and their utilization has increased. In particular, MIS is now routinely used in the treatment of degenerative spine disorders and has been shown to be as effective as conventional open spine surgeries. Although the procedures are not yet widely recognized in the context of complex spine surgery, the true potential in minimizing approach-related morbidity is far greater in the treatment of complex spinal diseases such as spinal trauma, spinal deformities, and spinal oncology. Conventional open spine surgeries for complex spinal disorders are often associated with significant soft tissue disruption, blood loss, prolonged recovery time, and postsurgical pain. In this article the authors review numerous cases of complex spine disorders managed with MIS techniques and discuss the current and future implications of these approaches for complex spinal pathologies.

Surgeon Perceptions of Minimally Invasive Spine Surgery

BACKGROUND: Interest in minimally invasive surgery (MIS) of the spine has driven the development of new and innovative techniques to treat an ever wider range of spinal disorders. Despite these new advances, spine surgeons have been slow in adopting MIS into their clinical practice. This study aims to provide a better understanding of the factors that have led to limited incorporation of these procedures into their practices. METHODS: Eighty-seven spine surgeons completed a questionnaire related to their perceptions of MIS. Respondents were asked to comment on their perceptions regarding the limitations and advantages of minimally invasive spine surgery. Survey results were then analyzed for both overall opinions and opinions based on the amount of MIS utilization in the respondents' current practices. RESULTS: The top 3 identified limitations of MIS of the spine were technical difficulty, lack of convenient training opportunities, and radiation exposure. Of these respondents, spine surgeons experienced in MIS were concerned more with radiation exposure than the lack of training opportunities. In contrast, spine surgeons with little MIS experience cited the lack of training opportunities as the most significant limitation. There was little concern related to the limited proven clinical efficacy of MIS of the spine. DISCUSSION: Technical factors, training opportunities, and radiation exposure appear to be the major obstacles to MIS of the spine. Most spine surgeons believe that MIS leads to faster return to daily activities, better long-term function, and decreased hospitalization. This may explain why most surgeons did not cite a lack of proven efficacy as a major limitation to MIS. These findings indicate that the widespread adoption of MIS of the spine will likely be driven through relatively simple means, such as improved training programs that strive to decrease the technical difficulty and limit radiation exposure of these procedures. It is unlikely that extensive clinical data alone, without such improved training programs, will be sufficient to drive widespread use of minimally invasive spine surgery.

Cauda equina syndrome

Cauda equina syndrome is a relatively uncommon condition typically associated with a large, space-occupying lesion within the canal of the lumbosacral spine. The syndrome is characterized by varying patterns of low back pain, sciatica, lower extremity sensorimotor loss, and bowel and bladder dysfunction. The pathophysiology remains unclear but may be related to damage to the nerve roots composing the cauda equina from direct mechanical compression and venous congestion or ischemia. Early diagnosis is often challenging because the initial signs and symptoms frequently are subtle. Classically, the full-blown syndrome includes urinary retention, saddle anesthesia of the perineum, bilateral lower extremity pain, numbness, and weakness. Decreased rectal tone may be a relatively late finding. Early signs and symptoms of a developing postoperative cauda equina syndrome are often attributed to common postoperative findings. Therefore, a high index of suspicion is necessary in the postoperative spine patient with back and/or leg pain refractory to analgesia, especially in the setting of urinary retention. Regardless of the setting, when cauda equina syndrome is diagnosed, the treatment is urgent surgical decompression of the spinal canal.