Posterior Decompression Techniques Research Articles

A randomized trial on three different minimally invasive decompression techniques for lumbar spinal stenosis. Five years follow-up from the NORDSTEN-SST.

The short-term clinical outcome for midline-preserving posterior decompression techniques was comparable. The aim of this study was to evaluate long-term clinical results after three different midline-preserving posterior decompression techniques. In the NORDSTEN spinal stenosis trial (NORDSTEN-SST) 437 patients were randomized to three different midline-retaining posterior decompression techniques: Unilateral laminotomy with crossover (UL), bilateral laminotomy (BL) and spinous process osteotomy (SPO). Primary outcome was the mean change in Oswestry disability index (ODI) score at five-years follow-up. Secondary outcomes were the proportion of patients classified as success, mean change in EQ-5D, ZCQ-score, NRS-score for leg and low back pain, a seven-point Global Perceived Effect (GPE) Scale and proportion of subsequential spinal surgery. The number of patients that completed follow-up data after five years was 358 (82%): In the UL, BL and SPO group the numbers were 122, 119 and 117, respectively. Mean age at baseline was 66.7 (SD 8.2) years, mean BMI was 27.8 (SD 4.1), and 172/358 (48%) were female. In the UL group the mean change was -18.2 (95% CI -21.0 -5.4), in the BL group it was -19.0 (95% CI -21.9-16.1) and in the SPO it was -18.6 (95% CI -21.6-15.7) (p = 0.917). No significant differences in the secondary outcomes between the three surgical groups were found, also the subsequent spinal surgery rates were similar. There were no significant differences in patient reported outcomes and subsequent spinal surgery rates after the three different decompression techniques at five-year follow-up.

What Happens to Sagittal Alignment Following Laminoplasty Versus Laminectomy and Fusion?

ObjectiveLaminectomy and fusion (LF) and laminoplasty (LP) are two sucessful posterior decompression techniques for cervical myelo-radiuclopathy. There is also a growing body of evidence describing the importance of cervical sagittal alignment (CSA) and its importance in outcomes. We investigated the difference between pre- and postoperative CSA parameters in and between LF or LP. Furthermore, studied predictive variables associated with change in cervical mismatch (CM) MethodsThis is retrospective cohort study of adults with cervical myeloradiculopathy in a single healthcare system. The primary outcomes are intra- and inter-cohort comparison of LF vs. LP radiographic parameters at pre- and postoperative time points. A secondary multivariable analysis of predictive factors was performed evaluating factors predicting postoperative CM. Results89 patients were included; 38 (43%) had LF and 51 (57%) underwent LP. Both groups decreased in lordosis (LF 11.4° vs 4.9°, p = 0.01; LP 15.2° vs 9.1°, p < 0.001), increased in cSVA (LF 3.4 vs 4.2cm, p = 0.01; LP 3.2 vs 4.2cm, p < 0.001), and increased in CM (LF 22.0° vs 28.5°, p = 0.02; LP 16.8° vs 22.3°, p = 0.002). There were no significant differences in the post operative CSA between groups. No significant predictors of change in pre- and postoperative CM were found ConslusionsThere were no significant pre-or post-operative differences following the two procedures, suggesting radiographic equipoise in well indicated patients. Across all groups, lordosis decreased, cSVA increased, and cervical mismatch increased. There were no predictive factors that led to change in cervical mismatch.

Safety and Efficacy of Posterior Upper Rib Excision and Decompression Technique for Surgical Treatment of Neurogenic Thoracic Outlet Syndrome

There are several approaches used for surgical treatment of neurogenic thoracic outlet syndrome (n-TOS). The posterior upper rib excision and decompression technique is a novel technique that was developed and used by the author for the past 8 years. The purpose of this paper is to report clinical outcomes of patients treated with this approach. All patients with n-TOS operated by single surgeon from 2015 to 2023 were retrospectively analyzed. Demographic, clinical, radiologic, surgical, and postoperative data were collected and reported with emphasis on efficacy and complications. The surgical success was evaluated subjectively as excellent, good, fair, poor, and bad. Radiologic data were analyzed to assess the extent of accessory/first rib removal. Eighty procedures were performed in 61 patients with a mean follow-up of 1153 (87-3048) days. The majority (60.7%) of patients were women, with 39.3% being men. In 11 cases (18%) causative factor was bone abnormality. Two patients were previously operated at another centers (3.3%). Total mean subjective improvement rate was 91.5%. More than half (55) of the patients reported "excellent" (>75%) and 6 "good" improvements (50%-75%); no fair, poor, and worse outcomes were reported. Patients reporting "good" outcome had statistically significant shorter follow-ups than the "excellent" group (P < 0.001). Complications included pleural opening, Horner syndrome, and apical hematoma, none of which were permanent. The posterior upper rib excision and decompression approach provides excellent clinical outcomes in patients with n-TOS. It allows better intraoperative visualization and removal of the first rib and full decompression of the neurovascular bundle.

Floating Laminoplasty for the Treatment of Compressive Myelopathy Accompanied by C1 Posterior Ring Hypoplasia: A Technical Note and Case Series

Posterior ring hypoplasia of the atlas (C1) is not common and in most cases is found by chance without symptoms. This disorder is sometimes accompanied by a mild C1-C2 instability or the presence of a space-occupying lesion such as ossification of posterior longitudinal ligament, pannus, or retro-odontoid pseudo-tumor, which are indications for surgery if symptomatic cord compression is present. A C1 posterior arch resection has been the procedure of choice but is associated with several fatal complications. We here present a novel posterior arch decompression technique that is relatively safer and easier and that involves mobilization and posterior translation of the posterior arch as a whole, similar to a vertebral body sliding osteotomy.

Comparison of posterior decompression techniques and conventional laminectomy for lumbar spinal stenosis.

ObjectivesTo compare the efficacy of posterior decompression techniques with conventional laminectomy for lumbar spinal stenosis.MethodsThe Embase, PubMed, and Cochrane Library databases were searched with no language limitations from inception to January 13, 2022. The main outcomes were functional disability, perceived recovery, leg and back pain, complications. A random effects model was used to pooled data. Risk ratio (RR), mean difference (MD) and 95% confidence interval (CI) were used to report results. The study protocol was published in PROSPERO (CRD42022302218).Results14 trials including 1,106 participants were included in the final analysis. Bilateral laminotomy was significantly more efficacious in improve functionality than laminectomy [MD: −2.94; (95% CI, −4.12 to −1.76)]. Low incidence of iatrogenic instability due to bilateral laminectomy compared with laminectomy [RR: 0.11; (95% CI, 0.02 to 0.59)]. In addition, between those who received bilateral laminotomy and those undergoing laminectomy, the result showed significant difference regarding recovery [RR: 1.31; (95% CI, 1.03 to 1.67)].ConclusionsThis study provides evidence that bilateral laminotomy has advantages in functional recovery, postoperative stability, and postoperative rehabilitation outcomes. Further research is needed to determine whether posterior techniques provide a safe and effective option for conventional laminectomy.

Navigated, Percutaneous Posterior Cervical Minimally Invasive Surgery Fixation: Technique and Nuances.

Cervical pedicle screw fixation provides a biomechanically superior fixation in comparison to traditional lateral mass screws. The traditional open technique has limited adoption due to technical challenges and significantly increased wound morbidity. Navigated, percutaneous pedicle screw fixation circumvents the traditional technical challenges and minimizes wound morbidity. We present here a technique description and case report of navigated, percutaneous posterior cervical minimally invasive fixation. Small lateral skin incisions are made on the neck using intraoperative computed tomography-guided navigation. Navigated cervical pedicle screws were placed using the proficient minimally invasive system (Spine Wave, Shelton, CT). Minimally invasive cervical fixation options have been limited traditionally. Navigated, percutaneous cervical minimally invasive surgery (MIS) fixation provides an effective, safe option for cervical fixation. This technique is described and illustrated in a case example of a patient who suffered a burst fracture and underwent treatment. Navigated, percutaneous posterior cervical MIS fixation provides biomechanically superior fixation while avoiding the morbidity of traditional, open approaches to the posterior cervical spine. Percutaneous cervical pedicle screw techniques will be pivotal in the continued advancement of posterior cervical decompression and fusion techniques. Navigated, percutaneous cervical minimally invasive fixation is an achievable form of cervical fixation with acceptable complication rates and radiographic outcomes.

Comparison of 3 Different Minimally Invasive Surgical Techniques for Lumbar Spinal Stenosis

Operations for lumbar spinal stenosis is the most often performed surgical procedure in the adult lumbar spine. This study reports the clinical outcome of the 3 most commonly used minimally invasive posterior decompression techniques. To compare the effectiveness of 3 minimally invasive posterior decompression techniques for lumbar spinal stenosis. This randomized clinical trial used a parallel group design and included patients with symptomatic and radiologically verified lumbar spinal stenosis without degenerative spondylolisthesis. Patients were enrolled between February 2014 and October 2018 at the orthopedic and neurosurgical departments of 16 Norwegian public hospitals. Statistical analysis was performed in the period from May to June 2021. Patients were randomized to undergo 1 of the 3 minimally invasive posterior decompression techniques: unilateral laminotomy with crossover, bilateral laminotomy, and spinous process osteotomy. Primary outcome was change in disability measured with Oswestry Disability Index (ODI; range 0-100), presented as mean change from baseline to 2-year follow-up and proportions of patients classified as success (>30% reduction in ODI). Secondary outcomes were mean change in quality of life, disease-specific symptom severity measured with Zurich Claudication Questionnaire (ZCQ), back pain and leg pain on a 10-point numeric rating score (NRS), patient perceived benefit of the surgical procedure, duration of the surgical procedure, blood loss, perioperative complications, number of reoperations, and length of hospital stay. In total, 437 patients were included with a median (IQR) age of 68 (62-73) years and 230 men (53%). Of the included patients, 146 were randomized to unilateral laminotomy with crossover, 142 to bilateral laminotomy, and 149 to spinous process osteotomy. The unilateral laminotomy with crossover group had a mean change of -17.9 ODI points (95% CI, -20.8 to -14.9), the bilateral laminotomy group had a mean change of -19.7 ODI points (95% CI, -22.7 to -16.8), and the spinous process osteotomy group had a mean change of -19.9 ODI points (95% CI, -22.8 to -17.0). There were no significant differences in primary or secondary outcomes among the 3 surgical procedures, except a longer duration of the surgical procedure in the bilateral laminotomy group. No differences in clinical outcomes or complication rates were found among the 3 minimally invasive posterior decompression techniques used to treat patients with lumbar spinal stenosis. ClinicalTrials.gov Identifier: NCT02007083.

Comparable increases in dural sac area after three different posterior decompression techniques for lumbar spinal stenosis: radiological results from a randomized controlled trial in the NORDSTEN study

PurposeTo investigate changes in dural sac area after three different posterior decompression techniques in patients undergoing surgery for lumbar spinal stenosis.Summary of background dataDecompression of the nerve roots is the main surgical treatment for lumbar spinal stenosis. The aim of this study was to radiologically investigate three commonly used posterior decompression techniques.MethodsThe present study reports data from one of two multicenter randomized trials included in the NORDSTEN study. In the present trial, involving 437 patients undergoing surgery, we report radiological results after three different midline retaining posterior decompression techniques: unilateral laminotomy with crossover (UL) (n = 146), bilateral laminotomy (BL) (n = 142) and spinous process osteotomy (SPO) (n = 149). MRI was performed before and three months after surgery. The increase in dural sac area and Schizas grade at the most stenotic level was evaluated. Three different predefined surgical indicators of substantial decompression were used: (1) postoperative dural sac area of > 100 mm2, (2) increase in the dural sac area of at least 50% and (3) postoperative Schizas grade A or B.ResultsNo differences between the three surgical groups were found in the mean increase in dural sac area. Mean values were 66.0 (SD 41.5) mm2 in the UL-group, 71.9 (SD 37.1) mm2 in the BL-group and 68.1 (SD 41.0) mm2 in the SPO-group (p = 0.49). No differences in the three predefined surgical outcomes between the three groups were found.ConclusionFor patients with lumbar spinal stenosis, the three different surgical techniques provided the same increase in dural sac area.Clinical trial registrationThe study is registered at ClinicalTrials.gov reference on November 22th 2013 under the identifier NCT02007083.

Thoracolumbar burst fractures in patients with neurological deficit: Anterior approach versus posterior percutaneous fixation with laminotomy

BackgroundThoracolumbar burst fractures (TLBFs) are the most common spinal trauma; however, their appropriate management has not yet been determined. In this study, we aimed to compare the clinical and radiological results of percutaneous pedicle screw fixation (PPSF) following posterior decompression technique versus anterior corpectomy and fusion technique for the treatment of TLBFs. MethodsA total of 46 patients (2002–2015) with TLBFs were included in this study. The inclusion criteria were a single-level Magerl type A3 burst fracture of the thoracolumbar junctional spine (T12–L2). The patients were divided into two groups; Group A (22 patients) underwent anterior corpectomy and fusion, and Group B (24 patients) underwent PPSF after posterior decompression. Anterior corpectomy and fusion surgery were performed in 22 cases before April 2009, and PPSF following posterior decompression technique was used in 24 cases since then. For radiological assessment, the kyphosis angle was measured preoperatively, early postoperatively, and at the last follow-up using the Cobb angle. Mean correction of the Cobb angle after surgery, and loss of correction between the immediate postoperative and final Cobb angle were calculated accordingly. All neurological deficits were identified in the initial evaluation and graded using the American Spinal Injury Association(ASIA) grading system. Perioperative parameters including operation time, amount of blood loss, and mean hospital stay were also evaluated. ResultsThe patients comprised 17 males and 5 females in Group A and 13 males and 11 females in Group B. In terms of the involved levels, there were three cases of T12, twelve L1, and seven L2 in Group A and one case of T12, thirteen L1, and ten L2 in Group B. The mean follow-up duration was 44.9 months in Group A and 14.7 months in Group B. The kyphotic angle was significantly corrected after surgery by 6.4° in Group A (p = 0.001) and 9.2° in Group B (p < 0.001). Among patients with neurological deficit, 11 of 15 in Group A and 20 of 23 in Group B demonstrated improvement by at least one ASIA grade at the final observation. However, there was no significant difference in neurological improvement between the two groups (p = 0.13). Mean operation time was significantly shorter (p < 0.001) and mean blood loss was significantly less (p < 0.001) in Group B than in Group A. Mean hospital stay was also significantly shorter in Group B (p < 0.001). ConclusionsSpinal canal decompression through small laminectomy followed by PPSF in the treatment of TLBFs with neurological deficits offers excellent clinical and radiological improvement as well as biomechanical stability. Furthermore, this can be a safe and effective surgical option with the advantage of less invasiveness in the treatment of TLBFs.

A comprehensive finite element model of surgical treatment for cervical myelopathy

BackgroundCervical myelopathy is a common and debilitating chronic spinal cord dysfunction. Treatment includes anterior and/or posterior surgical intervention to decompress the spinal cord and stabilize the spine, but no consensus has been made as to the preferable surgical intervention. The objective of this study was to develop an finite element model of the healthy and myelopathic C2-T1 cervical spine and common anterior and posterior decompression techniques to determine how spinal cord stress and strain is altered in healthy and diseased states. MethodsA finite element model of the C2-T1 cervical spine, spinal cord, pia, dura, cerebral spinal fluid, and neural ligaments was developed and validated against in vivo human displacement data. To model cervical myelopathy, disc herniation and osteophytes were created at the C4-C6 levels. Three common surgical interventions were then incorporated at these levels. FindingsThe finite element model accurately predicted healthy and myelopathic spinal cord displacement compared to motions observed in vivo. Spinal cord strain increased during extension in the cervical myelopathy finite element model. All surgical techniques affected spinal cord stress and strain. Specifically, adjacent levels had increased stress and strain, especially in the anterior cervical discectomy and fusion case. InterpretationsThis model is the first biomechanically validated, finite element model of the healthy and myelopathic C2-T1 cervical spine and spinal cord which predicts spinal cord displacement, stress, and strain during physiologic motion. Our findings show surgical intervention can cause increased strain in the adjacent levels of the spinal cord which is particularly worse following anterior cervical discectomy and fusion.

Bilateral translaminar osseous-channel assisted percutaneous full-endoscopic ligamentectomy decompression for thoracic myelopathy due to ossification of the ligamentum flavum: a technical note.

IntroductionA variety of surgical procedures have been introduced to treat patients with thoracic myelopathy (TM) caused by ossification of the ligamentum flavum (OLF). However, they are accompanied by significant trauma and risk, and their surgical outcomes are not always satisfactory.AimTo describe a bilateral translaminar osseous-channel assisted posterior percutaneous full-endoscopic ligamentectomy decompression (p-PELD) technique as a novel minimally invasive procedure for treating patients with TM due to OLF.Material and methodsA 51-year-old female patient with persistent thoracolumbar back pain and progressive numbness in the bilateral lower extremities for 2 years underwent percutaneous vertebroplasty (PVP) for T11 osteoporotic compression fractures (OCF) in a regional hospital one week prior to hospitalization. TM caused by canal stenosis and dorsal spinal cord compression at T10/11 secondary to OLF and an OCF at T11 were diagnosed based on clinical presentations and radiologic examinations. After bilateral p-PELD for TM was performed at T10/11, the result was confirmed based on postoperative radiographic and clinical results.ResultsThe bilateral OLF was completely removed by the p-PELD technique. No complications were encountered, and her symptoms were sufficiently improved after surgery. The VAS score was 6 points preoperatively and decreased to 0 points at the last follow-up (24 months). The modified Japanese Orthopaedic Association (mJOA) score improved from 2 points preoperatively to 10 points at the final follow-up.ConclusionsAs a minimally invasive technique, the bilateral translaminar osseous-channel assisted p-PELD procedure provided precise and sufficient decompression for the treatment of OLF-related TM.

The simple posterior operation for different types of malformations in the craniocervical junction with atlantoaxial dislocation

Objective: To explore the therapeutic effect of simple posterior reduction and decompression technique for different types of malformations in the craniocervical junction with atlantoaxial dislocation. Methods: The clinical data of 34 cases of different malformations in the craniocervical junction who were treated by the simple posterior internal fixation and decompression surgery in the department of neurosurgery of the first affiliated hospital of Nanchang University from March 2014 to March 2017 were analyzed retrospectively.In 34 cases, including 26 cases of basilar invagination with atlantoaxial dislocation (19 cases with atlanto occipital fusion, 12 cases with Chiari malformation, 13 cases with syringomyelia), 8 cases of odontoid malformation with atlantoaxial dislocation (2 cases with Chiari malformation, 1 case with flat skull base, 1 case with malformation of atlas). All the cases were performed Dynamic position X-ray film, CT scan and Three-dimensional reconstruction, and craniocervical MRI scan before the operation.The enlarged decompression of the occipital foramen, the fixation and fusion of the occipitocervical were performed during the operation, and the patients with cerebellar tonsillar hernia were performed decompression of the occipital small bone window. Results: All patients were followed up after the operation.The symptoms were obviously improved in 29 cases (85.3%), stability and no change in 5 cases (14.7%) and none postoperative neurological deterioration cases. Conclusion: The treatment of craniocervical junction malformation using simple posterior reduction and decompression technique is effective and has few complications, which can obviously improve the life quality of the patients.

How do posterior decompression techniques compare with conventional laminectomy in people with lumbar stenosis?

How do posterior decompression techniques compare with conventional laminectomy in people with lumbar stenosis?

Bone-Preserving Decompression Procedures Have a Minor Effect on the Flexibility of the Lumbar Spine

ObjectiveTo mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. MethodsA universal spine tester was used to measure the flexibility of six L2–L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3–L4; 2) on three specimens, the unilateral laminotomy was extended to L4–L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3–L4 in the first three specimens and at L4–L5 in the rest); and 4) pedicle screw fixation at the involved levels. ResultsUnilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. ConclusionIn vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

Effectiveness of Posterior Decompression Techniques Compared With Conventional Laminectomy for Lumbar Stenosis.

Effectiveness of Posterior Decompression Techniques Compared With Conventional Laminectomy for Lumbar Stenosis.

The effect of posterior fossa decompression in adult Chiari malformation and basilar invagination: a systematic review and meta-analysis.

Chiari malformation (CM) and basilar invagination (BI) are mesodermal malformations with disproportion between the content and volume of posterior fossa capacity and overcrowding of neural structures at the level of foramen magnum. Several alternatives for posterior approaches are available, including extradural (ED), extra-arachnoidal, and intradural (ID) approaches. The objectives are to evaluate the effect of several surgical techniques for posterior fossa decompression (PFD) in the outcomes of patients with CCJM and to evaluate complications in the techniques reported. A systematic review of the literature on the effects of PFD surgery was performed using the MEDLINE (via PubMed) database and the Cochrane Central Register of Controlled Trials. The PRISMA statement and MOOSE recommendations were followed. Five hundred and thirty-nine (539) articles were initially selected by publication title. After abstract analysis, 70 articles were selected for full-text analysis, and 43 were excluded. Ultimately, 27 studies were evaluated. The success rate (SR) with ED techniques was 0.76 versus 0.81 in EA technique and 0.83 in IA technique. All posterior fossa decompression techniques were very successful. Results from observational studies were similar to that of the randomized trial. The main complications were CSF fistulas, most common in patients with IA approach. The overall mortality rate was 1%.

Study-protocol for a randomized controlled trial comparing clinical and radiological results after three different posterior decompression techniques for lumbar spinal stenosis: the Spinal Stenosis Trial (SST) (part of the NORDSTEN Study)

BackgroundThere are several posterior decompression techniques for lumbar spinal stenosis (LSS). There is a trend towards performing less invasive surgical procedures, but no multicentre randomized controlled trials have evaluated the relative efficacy of these techniques at short and long-term.Method/designA multicentre randomized controlled trial [the Spinal Stenosis Trial (SST) (part of the NORDSTEN study)] including 465 patients aged 18–80 years with neurogenic claudication or radiating pain and MRI findings indicating lumbar spinal stenosis without spondylolisthesis is performed to compare three posterior decompression techniques: unilateral laminotomy with crossover, bilateral laminotomy and spinous process osteotomy. The primary outcome is change in Oswestry Disability Index (ODI 2 years postoperatively). Secondary outcomes are change in EQ-5D, Zurich Claudication Questionnaire, and Numeric Rating Scale for leg-pain and back-pain. Also recorded were Global Perceived Effect score, complications, length of hospital stay, reoperation rate 2 years postoperatively, difference in recurrence of symptoms or postoperative instability, and MRI change in the dural sac area. Further, a 5 and 10 years follow-up is planned with the same outcome measures.DiscussionNewer and less invasive techniques are increasingly favoured in surgery for LSS. This trial will compare the clinical and radiological results of three different techniques, and may contribute to better clinical decision making in the surgical treatment of LSS.Trial registrationClinicalTrials.gov reference: NCT02007083 (November 22, 2013).

Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis.

To compare the effectiveness of techniques of posterior decompression that limit the extent of bony decompression or to avoid removal of posterior midline structures of the lumbar spine versus conventional facet-preserving laminectomy for the treatment of patients with degenerative lumbar stenosis. A comprehensive electronic search of the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Web of Science, and the clinical trials registries ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform was conducted for relevant literature up to June 2014. A total of four high-quality RCTs and six low-quality RCTs met the search criteria of this review. These studies included a total of 733 participants. Three different techniques that avoid removal of posterior midline structures are compared to conventional laminectomy; unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy. Evidence of low or very low quality suggests that different techniques of posterior decompression and conventional laminectomy have similar effects on functional disability and leg pain. Only perceived recovery at final follow-up was better in patients that underwent bilateral laminotomy compared with conventional laminectomy. Unilateral laminotomy for bilateral decompression and bilateral laminotomy resulted in numerically fewer cases of iatrogenic instability, although in both cases, the incidence of instability was low. The difference in severity of postoperative low back pain following bilateral laminotomy and split-spinous process laminotomy was significantly less, but was too small to be clinically important. We found no evidence to show that the incidence of complications, length of the procedure, length of hospital stay and postoperative walking distance differed between techniques of posterior decompression. The evidence provided by this systematic review for the effects of unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy compared with conventional laminectomy on functional disability, perceived recovery and leg pain is of low or very low quality. Therefore, further research is necessary to establish whether these techniques provide a safe and effective alternative for conventional laminectomy. Proposed advantages of these techniques regarding the incidence of iatrogenic instability and postoperative back pain are plausible, but definitive conclusions are limited by poor methodology and poor reporting of outcome measures among included studies.

Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis.

The gold standard treatment for symptomatic lumbar stenosis refractory to conservative management is a facet-preserving laminectomy. New techniques of posterior decompression have been developed to preserve spinal integrity and to minimise tissue damage by limiting bony decompression and avoiding removal of the midline structures (i.e. spinous process, vertebral arch and interspinous and supraspinous ligaments). To compare the effectiveness of techniques of posterior decompression that limit the extent of bony decompression or avoid removal of posterior midline structures of the lumbar spine versus conventional facet-preserving laminectomy for the treatment of patients with degenerative lumbar stenosis. An experienced librarian conducted a comprehensive electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science, and the clinical trials registries ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) for relevant literature up to June 2014. We included prospective controlled studies comparing conventional facet-preserving laminectomy versus a posterior decompressive technique that avoids removal of posterior midline structures or a technique involving only partial resection of the vertebral arch. We excluded studies describing techniques of decompression by means of interspinous process devices or concomitant (instrumented) fusion procedures. Participants included individuals with symptomatic degenerative lumbar stenosis only. Two review authors independently assessed risk of bias using the Cochrane Back Review Group criteria for randomised controlled trials (RCTs) and the Newcastle-Ottawa Scale for non-randomised studies. We extracted data regarding demographics, intervention details and outcome measures. A total of four high-quality RCTs and six low-quality RCTs met the search criteria of this review. These studies included a total of 733 participants. Investigators compared three different posterior decompression techniques versus conventional laminectomy. Three studies (173 participants) compared unilateral laminotomy for bilateral decompression versus conventional laminectomy. Four studies (382 participants) compared bilateral laminotomy versus conventional laminectomy (one study included three treatment groups and compared unilateral and bilateral laminotomy vs conventional laminectomy). Finally, four studies (218 participants) compared a split-spinous process laminotomy versus conventional laminectomy.Evidence of low or very low quality suggests that different techniques of posterior decompression and conventional laminectomy have similar effects on functional disability and leg pain. Only perceived recovery at final follow-up was better in people who underwent bilateral laminotomy compared with conventional laminectomy (two RCTs, 223 participants, odds ratio 5.69, 95% confidence interval (CI) 2.55 to 12.71).Among the secondary outcome measures, unilateral laminotomy for bilateral decompression and bilateral laminotomy resulted in numerically fewer cases of iatrogenic instability, although in both cases, the incidence of instability was low (three RCTs, 166 participants, odds ratio 0.28, 95% CI 0.07 to 1.15; three RCTs, 294 participants, odds ratio 0.10, 95% CI 0.02 to 0.55, respectively). The difference in severity of postoperative low back pain following bilateral laminotomy (two RCTs, 223 participants, mean difference -0.51, 95% CI -0.80 to -0.23) and split-spinous process laminotomy compared with conventional laminectomy (two RCTs, 97 participants, mean difference -1.07, 95% CI -2.15 to -0.00) was significantly less, but was too small to be clinically important. A quantitative comparison between unilateral laminotomy and conventional laminectomy was not possible because of different reporting of outcome measures. We found no evidence to show that the incidence of complications, length of the procedure, length of hospital stay and postoperative walking distance differed between techniques of posterior decompression. The evidence provided by this systematic review for the effects of unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy compared with conventional laminectomy on functional disability, perceived recovery and leg pain is of low or very low quality. Therefore, further research is necessary to establish whether these techniques provide a safe and effective alternative for conventional laminectomy. Proposed advantages of these techniques regarding the incidence of iatrogenic instability and postoperative back pain are plausible, but definitive conclusions are limited by poor methodology and poor reporting of outcome measures among included studies. Future research is necessary to establish the incidence of iatrogenic instability using standardised definitions of radiological and clinical instability at comparable follow-up intervals. Long-term results with these techniques are currently lacking.

Letter to the Editor: The Extended Posterior Circumferential Decompression Technique in the Management of Tubercular Spondylitis with and without Paraplegia.

Dear Editor, We have read the published article by Rathinavelu at al. [1] entitled Posterior Circumferential Decompression Technique in the Management of Tubercular Spondylitis with and without Paraplegia with great interest. The study we well written and the authors described a new posterior procedure termed the Extended Posterior Circumferential Decompression (EPCD), a technique that manages tubercular spondylitis, in the presence or nonpresence of paraplegia. The objective of the study is noteworthy and we have some questions for authors: (1) In the study it was written, During this period, all cases of dorsal, dorso-lumbar and lumbar tuberculous spondylitis cases operated for any indication were performed using this technique. and Major indication for the procedure was paraplegia in 24 patients (59%), and contiguous vertebral body destruction with deformity in 17 patients (41%). What are the authors' operation indications? In 2008, Oguz et al. [2] developed a classification system for spinal tuberculosis based on seven clinical and radiological criteria. In this system, the researchers divided spinal tuberculosis into three categories by using these criteria, andrecommended specific therapeutic techniques for each type. Are the authors using a classification system to provide guidance in selecting the proper treatment approach for patients with spinal tuberculosis? (2) Which method did the authors use for differencial diagnosis from malignancy or methastasis before operations? Is the needle biopsy diagnostic significant? (3) What is the best option for multilevel tuberculosis spondylitis for patients having both thoracal and lumbar complications,with severe kyphosis or collapse? (4) Some authors advised using intraoperative cell salvage system in vertebral operations [3]. What is the author's opinion about this issue? We appreciate the author's comments on this concern.