Recurrent Disc Herniation Research Articles

Perioperative results following open and minimally invasive single-level lumbar discectomy

Lumbar discectomy is the most commonly performed spine surgery and in recent years, minimally invasive tubular discectomy has become increasingly popular among surgeons and patients. However, recent reports have raised the question of whether or not patients have shorter hospitalizations following minimally invasive discectomy. From 2005 to 2010, we analyzed 109 patients who underwent elective, single-level lumbar discectomy for central or paracentral disc herniations. A retrospective analysis of medical records was performed for perioperative complications. Tubular discectomy was not associated with increased rates of durotomy, nerve root injury, wound complications, or recurrent disc herniations requiring additional surgery. Minimally invasive tubular discectomy in the lumbar spine results in a small, but statistically significant, advantage in length of stay compared to conventional open microdiscectomy. While small on an individual basis, this difference may translate to substantial economic savings over time when one considers how many discectomies are performed in aggregate.

Anterior discectomy and total disc replacement for three patients with multiple recurrent lumbar disc herniations

Although results of primary discectomy are generally excellent with relief of leg pain, recurrent lumbar disc herniation is relatively common ranging from 5% to 25%. Patients with recurrent herniation may undergo revision surgery; however, this carries with it increased risks and lower success rates. Many surgeons will advocate a fusion in addition to repeat discectomy after the third recurrent herniated disc. With the approval of lumbar total disc arthroplasty, there now exists another option for the patient with three or more recurrent disc herniations to preserve motion, theoretically decrease the rate of adjacent-level disease, and ameliorate the patient's symptoms. The purpose of this case report is to describe our experience using total disc replacement (TDR) in three patients after prior partial hemilaminectomy and discectomy for the treatment of a third and fourth recurrent lumbar disc herniation. This article is a report of three cases from a spine specialty center describing an alternative surgical technique for patients with multiple recurrent lumbar disc herniation. Comprehensive chart review of three patients with recurrent lumbar herniation who underwent TDR. Anterior discectomy and TDR were undertaken, and at most recent follow-up (8-12 months), all patients had improvement of their visual analog scale and Oswestry Disability Index. No patient had postoperative complications or reoperation. Recurrent disc herniation is a relatively common problem that may be difficult to treat. Traditionally, a patient presenting with three or more recurrent disc herniation may likely have undergone revision discectomy with fusion. The current case report suggests that TDR may be an alternative option in select patients.

Minimally Invasive Transforaminal Lumbar Interbody Fusion for Degenerative Spine

Transforaminal lumbar interbody fusion (TLIF) is a popular, well established technique for achieving circumferential fusion by a posterior approach. In an effort to minimize surgical approach-related morbidity, surgeons have devised minimally invasive (MIS) techniques that use specialized retractor systems, using muscle-splitting exposure, to provide surgical access directly over the region of interest. The indications for performing a MIS TLIF are similar to the conventional TLIF and include low-grade spondylolisthesis, degenerative disc disease with back pain with or without radiculopathy, and recurrent disc herniations. The surgical indications, contraindications, and an overview of the surgical technique are presented in this review. A systematic literature review was also undertaken to identify studies that compared MIS TLIF with open TLIF. The search revealed 8 controlled cohort studies that have shown significantly lower postoperative morbidity in the MIS TLIF cohorts while having comparable clinical outcomes with open TLIF cohorts. The higher complication rate during the learning curve of this procedure remains a concern. However, the evidence available is of low quality, and well designed prospective controlled trials are needed to decisively prove the benefits observed so far.

Postoperative Befunde an der Wirbelsäule

Postoperative imaging after spinal surgery is usually performed to document the correct positioning of implants or to rule out complications if patients still suffer from pain after surgery. Depending on the question various imaging modalities can be used all of which have benefits and limitations. Conventional X-ray is used for the documentation of the correct positioning of spinal implants, stability (olisthesis) and during follow-up to rule out fractures or instability of the implants, whereas soft tissue changes cannot be completely assessed. Besides these indications, imaging is usually performed because of ongoing symptoms (pain for the most part) of the patients. Soft tissue changes including persistent or recurrent herniated disc tissue, hematoma or infection can best be depicted using magnetic resonance imaging (MRI) which should be performed within the immediate postoperative period to be able to distinguish physiological development of scar tissue from inflammatory changes in the area of the surgical approach. Often imaging alone cannot differentiate between these and imaging can therefore only be considered as an adjunct. Computed tomography is the modality of choice for the evaluation of bony structures and an adjunct of new therapies such as image-guided application of cement for kyphoplasty or vertebroplasty.

New Techniques in Lumbar Spinal Instrumentation: What the Radiologist Needs to Know

Lumbar spinal fusion is a commonly performed procedure, and, despite changes in cage types and fixation hardware, radiologists have, over the years, become familiar with the imaging features of typical spinal fusion and many of the complications seen in patients after surgery, including pseudoarthrosis, hardware loosening, and recurrent or residual disk herniation. Recently, however, novel approaches and devices have been developed, including advances in minimally invasive surgery, the increasing use of osteoinductive materials, and a wide variety of motion-preserving devices. These new approaches and devices manifest with characteristic imaging features and the potential for unusual and unexpected complications. Several of these devices and approaches are experimental, but many, including those devices used in lateral approaches to fusion, as well as the use of bone morphogenic protein, disk arthroplasty, and interspinous spacers, are seen with increasing frequency in daily clinical practice. Given the recent advances in spinal fusion surgery, it is important that radiologists have a basic understanding of the rationale behind these procedures, the common imaging features of the devices, and the complications associated with their use.

The Role of Fusion for Recurrent Disk Herniations

For patients with symptomatic recurrent disk herniations that have failed nonoperative treatment, surgical treatment can be considered. Although simple repeat diskectomy can be an effective treatment for first time recurrences, many surgeons would consider the addition of fusion, particularly for second or third recurrences. With a lack of high-level evidence, decision making concerning when and how to fuse for a recurrent lumbar disk herniation remains largely surgeon-dependent because a variety of options are available. Although there are limited data, both posterolateral and interbody fusion can be effective. Future study is needed to better define the indications and ideal method of fusion for recurrent disk herniations.

Comparison of the effect of single-site and multiple-site disk fenestration on the rate of recurrence of thoracolumbar intervertebral disk herniation in dogs

To prospectively assess whether multiple-site disk fenestration decreases the incidence of recurrent thoracolumbar intervertebral disk herniation (IVDH), compared with single-site disk fenestration, in small-breed dogs treated for IVDH. Randomized controlled clinical trial. 207 client-owned dogs. Dogs undergoing decompressive surgery of the spinal cord because of thoracolumbar IVDH between 2001 and 2004 were randomly assigned to receive single-site disk fenestration at the level of surgical decompression (n = 103) or multiple-site disk fenestration of all disks from T11 through L4 (104). Follow-up consisted of complete reevaluation of patients, telephone surveys, and further surgery if signs indicative of recurrence occurred. 189 dogs were available for long-term follow-up: 95 dogs in the single-site disk fenestration group and 94 in the multiple-site disk fenestration group. Twenty-four dogs developed 28 confirmed episodes of recurrent thoracolumbar IVDH. The rate for first-time recurrence was 12.7% (24/189). First-time recurrence rates for single-and multiple-site disk fenestration groups were 17.89% (17/95) and 7.45% (7/94), respectively. Dogs undergoing single-site disk fenestration were significantly more likely to have recurrent thoracolumbar IVDH than were dogs undergoing multiple-site disk fenestration. Disk mineralization at the time of first surgery was associated with recurrence, and 87.5% (21/24) of recurrences occurred at a disk space adjacent to or 1 disk away from the initial lesion. Regardless of disk fenestration group, 22 of 24 (91.7%) recurrences occurred at a nonfenestrated disk space. Multiple-site disk fenestration decreased the rate of recurrent IVDH in small-breed dogs, compared with the use of single-site disk fenestration.

Resultados a largo plazo de la microdiscectomía lumbar en una población laboralmente activa

In the treatment of the lumbar disc herniaton (LDH) microdiscectomy constitutes one of the standard procedures. In the present study we have analyzed the clinical outcome of the lumbar microdis- cectomy in a series of worker patients who underwent surgery in our service. Retrospective analysis and a 5-year follow up, of a series of 142 patients operated on by means of lumbar microdiscectomy in the 2004-2005 period. The clinical outcome was analyzed according to the "Herron and Turner" outline: pain reduction, use of medical treatment, restriction in the ability to perform physical activities, and return to work. 116 men and 26 women, with an average age of 37.9 and 45.4 years respectively, underwent surgery because of LDH. In the clinical aspect, sciatica was predominant over low back pain in a ratio of three to one. The L5-S1 discal level was operated on in 68.3% of the cases. It was considered that occupational activities gave rise to damage in 107 patients (75.3%). Besides a symptomatic disc, there was an additional injured disc in 44.3% of the cases. An initial unfavourable outcome was seen in 42 patients (33%), 15 of which recovered from in an interval of 3 months, and another fifteen within a one year period. A re-operation was necessa ry in 16 patients because of recurrent lumbar disc herniation (11%). Work reintegration was achieved in 83.3% (119/142) of the cases. After a 5-year follow up, we stated the consistency of the clinical result. We analyzed the intervertebral disc behaviour as regards sex, age, variety of discal herniation, additional disc, outcome and re-operation variables. After the analysis of the type of discal herniation and additional disc we defined three disc injury patterns. We consider microdiscectomy as the technique of choosing for the treatment of recurrence disc herniation. Between the working class, discal injury predominates in young men, as a consequence of the annulus breakage, or an annulus plus posterior longitudinal ligament breakage (traumatic herniae). Frequently it was observed that more than one disc was involved, and a left lateralization.

Microendoscopic versus Open Discectomy for Lumbar Disc Herniation: A Prospective Randomised Study

To compare the outcomes of microendoscopic discectomy (MED) versus open discectomy for lumbar disc herniation. 80 men and 32 women aged 26 to 57 (mean, 37) years with a single-level disc herniation were randomised to undergo MED (n=55) or open (fenestration/laminotomy) discectomy (n=57). Patients were assessed pre- and post-operatively (at week 6, month 6, and year one). The 2 groups were compared with respect to surgical time, anaesthesia time, duration of hospital stay, intra-operative blood loss, weight of disc material removed, and self-evaluated low back pain and functional outcome (using the Oswestry low back pain disability questionnaire). Surgical and anaesthesia times were significantly longer, but blood loss and hospital stay were significantly reduced in patients having MED than open discectomy. The improvement in the Oswestry score in both groups was significant at week one, but not at other follow-ups. The complication rate was similar in both groups. One patient with MED had a recurrence of disc herniation after 7 months and was treated with open discectomy. Both methods are equally effective in relieving radicular pain. MED entailed shorter hospital stay, less morbidity, and earlier return to work. Nonetheless, it is a demanding technique and should not be attempted without specific instruction and training.

The midterm efficacy evaluation of artifical nucleus prosthesis replacement in treatment of lumbar disc herniation

Objective To evaluate the midterm efficacy of prosthetic disc nucleus ( PDN) replacement for the treatment of lumbar disc herniation. Methods Twenty cases of lumbar disc herniation( including one case of recurrent lumbar disc herniation) were treated with PDN. The twenty cases were followed-up 5.4 ～6.2 years( mean 5.7 years). Functional,and radiographic follow-up examinations,MRI and follow-up records of all patients were reviewed carefully. Results Clinical evaluation at the end of follow-up,there were 10 cases in excellent,6 cases in good,2 cases in fair and 2 cases in poor,and good rate was 80%. One patient accepted the revision operation to remove the PDN because of device migration. One patient accepted the fusion because of adjacent segment disease. The others experienced pain relief, and resumed their normal life and work. The average Oswestry score and VAS get better significantly. Conclusion The PDN was effective in treating patients with lumbar disc herniation. However, the medium term complications of device subsidence should be taken seriously. Key words: Lumbar vertebrae; Intervertebral disc displacement; Prosthesis implantation

Instrumented transforaminal lumbar interbody fusion with single cage for the treatment of degenerative lumbar disease

There are several practical problems encountered in the TLIF procedure with implantation of two titanium cages, such as difficulty in achieving symmetric positioning with two cages, loosening of the first cage following insertion of the second cage and higher direct costs to the patient. From January 2005 to December 2007, a total of 76 consecutive patients treated with instrumented TLIF with single cage and excised local bone were enrolled in the current study. There were 45 males and 31 females aged between 31 and 75 years (mean 50.9 years). Forty-five patients had degenerative disc diseases alone, 23 had associated isthmic or degenerative spondylolisthesis and 8 had recurrent disc herniations. Clinical outcomes were evaluated using the Oswestry Disability Index and a visual analog scale. Intervertebral height and fusion status were assessed on X-ray and two-dimensional computed tomography reconstruction. All the patients followed up. The mean follow-up period was 21.8 months (range from 12 to 48 months). No nerve injuries occurred during operation. Postoperative ODI and VAS scores in all the patients were more than the preoperative ones with significant differences. All the patients had complete interbody fusion and, at the final follow-up, none had instrumentation failure. Postoperative intervertebral height in all the patients was better than the preoperative ones with statistical significances. Instrumented TLIF with single cage is a safe and effective method for the treatment of degenerative lumbar diseases.

Posterior ring apophysis separation combined with lumbar disc herniation in adults: a 10-year experience in the surgical management of 87 cases

The association of posterior ring apophysis separation (PRAS) with lumbar disc herniation (LDH) is uncommon and represents a true subgroup of disc herniation mainly seen in the adolescent population. The objective of this study was to describe a decade of experience in the care of adult patients with PRAS with LDH, giving particular attention to its diagnosis, surgical treatment, and outcome. This retrospective study focuses on a case series of adult patients with PRAS associated with LDH who underwent surgery for lumbar disc disease in the author's neurosurgical department between 1999 and 2008. Posterior ring apophysis separation was diagnosed in 87 (5.35%) of 1625 patients surgically treated for LDH; these patients made up the PRAS group. During a 6-month period in 2005, LDH without PRAS was diagnosed in 89 consecutive patients at the same facility; these patients constituted the control group. Presenting symptoms, physical examination findings, and preoperative imaging results were obtained from medical records. Immediate operative results were assessed, as were complications, long-term outcome, and the need for repeat surgery. This study is the first to document the distinguishing features between adult patients with and those without PRAS. The difference in average age was statistically significant (p < 0.001) between the study group (36.22 years) and the control group (44.30 years), as was the incidence of male patients (86.20% vs 71.91%, p = 0.020), incidence of military patients (74.71% vs 57.30%, p = 0.015), average duration of symptoms (16.13 vs 8.4 months, p = 0.016), and incidence of reactive scoliosis (19.54% vs 4.49%, p = 0.002). The most common anatomical location of disc herniation in the PRAS group was L5-S1 (51.72%) versus L4-L5 (53.93%) in the control group (p = 0.017). In terms of previous injury, motor deficits, back and/or leg pain, lateral or central location of LDH, mean anteroposterior diameter of disc herniation, hard or soft discs, and surgical complications, there was no statistical difference between the 2 patient groups. Similarly, there was no difference in recurrence rates and clinical outcomes between the patients with or without PRAS. Posterior ring apophysis separation with LDH is probably more common in adults than is generally recognized. It must be suspected when young male patients with persistent sciatic scoliosis and no history of injury show signs of calcified LDH. Computed tomography scanning with sagittal reconstructions is the procedure of choice for diagnosing. The L5-S1 intervertebral disc level is most commonly affected, especially the superior endplate of S-1. This condition needs more extensive surgical exposure and resection to relieve the nerve impingement. The occurrence of an apophyseal lesion was not associated with recurrent disc herniation or a fair outcome.

Rapid Repeated Recurrent Lumbar Disc Herniation after Microscopic Discectomies

The recurrence of lumbar disc herniation after single-level discectomy is a well-known complication. Pain and neurological symptoms during the first week after surgery can be caused by missed pathology or early recurrent disc herniation. However, recurrent disc herniation that causes segmental instability after repeat operation is rare. Here, we report a case of a 42-year-old woman having a rare complication of rapid recurrent lumbar disc herniation after 2 microscopic discectomies within a short period. We suggest that rapid disc fragmentation and rapid growth of annular defect caused rapid repeated recurrence of lumbar disc herniation and segmental instability. Further investigation will be needed to identify the cause of this rapid disc degeneration.

Revisional Percutaneous Full Endoscopic Disc Surgery for Recurrent Herniation of Previous Open Lumbar Discectomy

Study DesignA retrospective study.PurposeTo determine the feasibility and effectiveness of revisional percutaneous full endoscopic discectomy for recurrent herniation after conventional open disc surgery.Overview of the LiteratureRepeated open discectomy with or without fusion has been the most common procedure for recurrent lumbar disc herniation. Percutaneous endoscopic lumbar discectomy for recurrent herniation has been thought of as an impossible procedure. Despite good results with open revisional surgery, major problems may be caused by injuries to the posterior stabilized structures. Our team did revisional full endoscopic lumbar disc surgery on the basis of our experience doing primary full endoscopic disc surgery.MethodsBetween February 2004 and August 2009 a total of 41 patients in our hospital underwent revisional percutaneous endoscopic lumbar discectomy using a YESS endoscopic system and a micro-osteotome (designed by the authors). Indications for surgery were recurrent disc herniation following conventional open discectomy; with compression of the nerve root revealed by Gadolinium-enhanced magnetic resonance imaging; corresponding radiating pain which was not alleviated after conservative management over 6 weeks. Patients with severe neurologic deficits and isolated back pain were excluded.ResultsThe mean follow-up period was 16 months (range, 13 to 42 months). The visual analog scale for pain in the leg and back showed significant post-treatment improvement (p < 0.001). Based on a modified version of MacNab's criteria, 90.2% showed excellent or good outcomes. There was no measurable blood loss. There were two cases of recurrence of and four cases with complications.ConclusionsPercutaneous full-endoscopic revisional disc surgery without additional structural damage is feasible and effective in terms of there being less chance of fusion and bleeding. This technique can be an alternative to conventional repeated discectomy.

Surgery for Recurrent Lumbar Disc Herniation During Pregnancy: A Case Report.

A few cases of lumbar disc herniation (LDH) that have been treated by surgery during pregnancy have been reported in the literature. However, symptomatic recurrent LDH during pregnancy has been rarely reported. A 32-year-old parous woman presented with lumbago and severe right leg pain at 20 weeks' gestation. Eleven years prior to admission, she had undergone an open discectomy for right-sided LDH at the L4-5 level. Magnetic resonance imaging (MRI) showed a recurrent disc herniation that affected the nerve root at the right L4-5 level. The radiating pain did not respond to conservative treat-ment. Revision surgery was performed under general anesthesia and in the left lateral position to avoid fetal stress and aortocaval compression, and the ruptured disc particle was completely removed. Postoperatively, the radiating pain was completely relieved. She delivered a full-term healthy girl (birth weight, 3.39 kg) at 40 weeks' gestation by normal vaginal delivery. We report the rare case of a 32-year-old parous woman with recurrent LDH that was successfully treated by revision surgery. In recurrent LDH patients with incapacitating pain who do not respond to opioid injections, surgical treat-ment could lead to a satisfactory outcome maintaining pregnancy.

Clinical Results of Interlaminar Approach for Endoscopic Discectomy in the Herniated Lumbar Disc at L5-S1

Objective: This retrospective study of 57 patients was performed to evaluate the therapeutic effectiveness of percutaneous endoscopic surgery by using interlaminar approach (ILA) in symptomatic lumbar disc herniation (LDH) at L5-S1. Methods: Visual analogue pain score (VAS) and Oswestry disability index (ODI) were used to assess the clinical outcome. All assessment was done on 1 day before the operation, 3 days, 3 months and 12 months after the operation Results: The mean preoperative back and leg VAS was decreased from 5.6±1.4, 8.5±1.7 to 1.8±1.2, 1.5±1.3 at 3 days, 1.2±1.1, 1.8±1.7 at 3 months, and 1.4±1.7, 1.6±1.3 at 12 months after the operation. Mean preoperative ODI score was improved from 46.8±22.4% to 17.7±11.6% at 3 days, 15.3±10.1% at 3 months, and 16.2±9.3% at 12 months after the operation. There were 2 cases of surgical failure due to dural tearing and calcified disc. One patient presented with transient paresthesia postoperatively. Two patients showed the recurrent disc herniation at the same level and same side, and underwent second open surgery. Conclusion: The present study revealed that percutaneous endoscopic surgery by using ILA is an effective surgical modality for the selective cases of LDH at L5-S1.

Management of Pain of Post Lumbar Surgery Syndrome: One-Year Results of a Randomized, Double-Blind, Active Controlled Trial of Fluoroscopic Caudal Epidural Injections

Post lumbar surgery syndrome represents a cluster of nomenclature and syndromes following spine surgery wherein the expectations of the patient and spine surgeon are not met, with persistent pain following lumbar surgery. Multiple causes have been speculated to cause pain after lumbar surgery. Epidural steroid injections are most commonly used in managing post surgical pain in the lumbar spine. However, there is a paucity of evidence of epidural injections in managing chronic low back pain with or without lower extremity pain in post surgery syndrome. A randomized, double-blind, active controlled trial. An interventional pain management practice, a specialty referral center, a private practice setting in the United States. To evaluate the effectiveness of caudal epidural injections in patients with chronic low back and lower extremity pain after surgical intervention with post lumbar surgery syndrome. One-hundred forty patients were randomly assigned to one of 2 groups; Group I patients received caudal epidural injections with local anesthetic (lidocaine 0.5%), whereas Group II patients received caudal epidural injections with 0.5% lidocaine 9 mL mixed with 1 mL of 6 mg non-particulate Celestone. Randomization was performed by computer-generated random allocation sequence by simple randomization. Multiple outcome measures were utilized which included the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake with assessment at 3 months, 6 months, and 12 months post-treatment. Significant pain relief and disability reduction were described as 50% or more reduction in scores from baseline. Combined pain relief (>/=50%) and disability reduction was recorded in 53% of the patients in the local anesthetic group, and 59% of patients in the local anesthetic and steroid group with no significant differences noted with or without steroid over a period of one-year. However, the data from the successful group showed improvement in 70% of patients in Group I and 75% of patients in Group II. The average procedures per year were 4 with an average total relief per year of 38.1 ± 14.5 weeks in Group I and 38.4 ± 13.2 weeks in Group II over a period of 52 weeks in the successful group. The results of this study are limited by the lack of a placebo group and one-year outcomes. Caudal epidural injections in chronic function-limiting low back pain in post surgery syndrome without facet joint pain may be effective in a significant proportion of patients with improvement in functional status and significant pain relief. NCT00370799.

Answer to the letter to the editor of Carl Hans Fürstenberg et al. (2010) concerning manuscript “transforaminal endoscopic surgery for lumbar stenosis: a systematic review” by Jorm Nellensteijn, Raymond Ostelo, Ronald Bartels, Wilco Peul, Barend Van Royen, Maurits Van Tulder. Eur Spine J 19:879–886

In the letter to the editor it is suggested that we might have missed relevant evidence. Not including ‘discectomy’ in the search strategy is pointed out as the main reason. But apparently there is confusion regarding the fact that we published two systematic reviews, both on transforaminal endoscopic surgery. One focuses on symptomatic lumbar disc herniations [1] and the second one on lumbar stenosis [2]. We combined the search strategy for these two reviews for efficiency reasons. The keywords were used as MESH headings and free text words; discectomy was included in the search strategy [1]. The full search strategy is available upon request. In the present review we focus on stenosis. The SCIATICA-Med trial [3, 4] included patients with lumbar disc herniation and was therefore not eligible for this review. Moreover, it clearly uses a different technique than the transforaminal endoscopic surgery. Therefore, this study was also excluded from our systematic review on symptomatic lumbar disc herniations [1]. The German health technology assessment report [5] focuses on the treatment of disc prolapse and not stenosis. The study by Hermantin et al. [6] met the inclusion criteria for review on symptomatic lumbar disc herniations [1] and was included (see Ref. 11 of that review). The report by the Dutch Health Care Insurance also focuses on lumbar disc herniation and was based on our review [1]. The three key publications [7–9] that we reportedly ‘omitted’ were included in our review on symptomatic lumbar disc herniations [1] as they included patients with lumbar disc herniation. The study by Molyneux was not found as our search strategy was up to November 2009. Conference proceedings did not meet our definition of ‘published papers’ and therefore Lewandrowski [10] and Iprenburg [11] were not included. The reference by Morgenstern [12] could not be retrieved, as the European Musculoskeletal Review seems not to be indexed in the databases we searched. The study by Hoogland [13] includes patients with recurrent lumbar disc herniation, not stenosis. In assessing the risk of bias, we followed the guidelines of the Cochrane Back Review Group and, therefore, we think that the doubt the authors convey regarding ‘the publication quality assessment criteria’ is without any foundation. In conclusion, no randomized controlled trial, but only seven observational studies were identified and no relevant papers are missed. All these studies had a high risk of bias. Consequently, the conclusion that there is no valid evidence on the effectiveness of transforaminal endoscopic surgery for lumbar stenosis is supported by the data.

Die Behandlung der dynamischen Spinalkanalstenose mit einem interspinösen Spacer

Indirect decompression of the spinal canal and the neuroforamina by means of interspinous process distraction and limitation of extension movements. Reduction of forces acting on the posterior joint structures of a functional spinal unit (posterior anulus, facet joints, intervertebral discs). Primary indication: Spinal claudication with improvement of the clinical symptomatology upon taking an inclined position. Secondary indication: Low back pain in the presence of accompanying retrolisthesis. Hyperlordosis Facet joint complaints Annulus lesions with high intensity zones (HIZ) M. Baastrup ("kissing spine"). Adjacent segment preservation (e.g. prophylaxis of recurrent disc herniation after discectomy or topping-off following previous fusion). Spinal instabilities which prohibit a solid fixation of the implant (e.g. spondylolysis, isthmus fractures, condition following previous (hemi-) laminectomy) Degenerative spondylolisthesis ffl 1st degree. Severe structural narrowing of the spinal canal. Absent dynamic aspect without improvement upon inclination, segmental ankylosis. Positioning of the patient in an inclined position. Approximately 4 cm median skin incision, bilateral access with preservation of the supraspinous ligament. Perforation of the interspinous ligament. Following interspinous distraction the adequate size implant is established. Insertion of the interspinous process distraction device (IPD) unit and fixation of the mobile wing unit from the contralateral side. Medial positioning and solid fixation of the implant by connecting the two implant units. Lumbar orthosis (optional), otherwise no further support required. Daily living activities immediately after the operation. Physiotherapeutic exercises (optional). Low impact sporting activities from 2nd week after operation, intense/ high impact sporting activities from 6 months postoperatively. Previous studies have reported satisfactory results for interspinous distraction devices for the treatment of dynamic spinal canal stenosis. However, the majority of these previously published studies are based on data with only shortterm follow-up or small patient numbers. In particular, the results of interspinous spacers for the treatment of different indications have not been evaluated separately. Complications and long-term results still need to be established.

Survivorship analysis of 150 consecutive patients with DIAM™ implantation for surgery of lumbar spinal stenosis and disc herniation

Recently, the Device for Intervertebral Assisted Motion (DIAM™) has been introduced for surgery of degenerative lumbar disc diseases. The authors performed the current study to determine the survivorship of DIAM™ implantation for degenerative lumbar disc diseases and risk factors for reoperation. One hundred and fifty consecutive patients underwent laminectomy or discectomy with DIAM™ implantation for primary lumbar spinal stenosis or disc herniation. The characteristics of the 150 patients included the following: 84 males and 66 females; mean age at the time of surgery, 46.5 years; median value of follow-up, 23 months (range 1-48 months); 96 spinal stenosis and 54 disc herniations; and 146 one-level (115, L4-5; 31, L5-6) and 4 two-level (L4-5 and L5-6). In the current study, due to lumbosacral transitional vertebra (LSTV) L6 meant lumbarization of S1 and this had a prominent spinous process so that the DIAM™ was implanted at L5-6. Reoperations due to any reasons of the DIAM™ implantation level or adjacent levels were defined as a failure and used as the end point for determining survivorship. The cumulative reoperation rate and survival time were determined via Kaplan-Meier analysis. The log-rank test and Cox regression model were used to evaluate the effect of age, gender, diagnosis, location, and level of DIAM™ implantation on the reoperation rate. During a 4-year follow-up, seven patients (two males and five female) underwent reoperation at the DIAM™ implantation level, giving a reoperation rate of 4.7%. However, no patients underwent reoperation for adjacent level complications. The causes of reoperation were recurrent spinal stenosis (n = 3), recurrent disc herniation (n = 2), post-laminectomy spondylolisthesis (n = 1), and delayed deep wound infection (n = 1). The mean time between primary operation and reoperation was 13.4 months (range 2-29 months). Kaplan-Meier analysis predicted an 8% cumulative reoperation rate 4 years post-operatively. Survival time was predicted to be 45.6 ± 0.9 months (mean ± standard deviation). Based on the log-rank test, the reoperation rate was higher at L5-6 (p = 0.002) and two-level (p = 0.01) DIAM™ implantation compared with L4-5 and one-level DIAM™ implantation. However, gender (p = 0.16), age (p = 0.41), and diagnosis (p = 0.67) did not significantly affect the reoperation rate of DIAM™ implantation. Based on a Cox regression model, L5-6 [hazard ratio (HR), 10.3; 95% CI, 1.7-63.0; p = 0.01] and two-level (HR, 10.4; 95% CI, 1.2-90.2; p = 0.04) DIAM™ implantation were also significant variables associated with a higher reoperation rate. Survival time was significantly lower in L5-6 (47 vs. 22 months, p = 0.002) and two-level DIAM™ implantation (46 vs. 18 months, p = 0.01) compared with L4-5 and one-level DIAM™ implantation. The current results suggest that 8% of the patients who have a DIAM™ implantation for primary lumbar spinal stenosis or disc herniation are expected to undergo reoperation at the same level within 4 years after surgery. Based on the limited data set, DIAM™ implantation at L5-6 and two-level in patients with LSTV are significant risk factors for reoperation.