Interspinous Spacer Research Articles

Comparison of Adverse Outcomes Following Placement of Superion Interspinous Spacer Device Versus Laminectomy and Laminotomy.

Current evidence suggests placement of the Superion interspinous spacer (SISS) device compared with laminectomy or laminotomy surgery offers an effective, less invasive treatment option for patients with symptomatic lumbar spinal stenosis. Both SISS placement and laminectomy or laminotomy have risks of complications and a direct comparison of complications between the 2 procedures has not been previously studied. The purpose of this study is to compare the short-term complications of the SISS with laminectomy or laminotomy and highlight device-specific long-term outcomes with SISS. Via retrospective review, 189 patients who received lumbar level SISSs were compared with 378 matched controls who underwent primary lumbar spine laminectomy or laminotomy; data were collected from the American College of Surgeons National Surgical Quality Improvement Program database. Complications analyzed included rates of wound infection, pulmonary embolism, deep venous thrombosis, urinary tract infection, sepsis, septic shock, cardiac arrest, death, and reoperation within 30 days of index surgery. Differences between groups were analyzed using the χ2test. Device-specific complication (DSC) rates included device malfunction or misplacement (DM), device explantation (DE), spinous process fracture (SPF), and subsequent spinal surgery (SSS). No differences in demographics or comorbidities existed between groups. There was no significant difference in rates of complications between groups. A total of 44.4% of patients in the SISS group experienced DSCs with 11.1% of patients experiencing DM, 21.1% experiencing an SPF, 20.1% requiring DE, and 24.3% requiring SSS. Having at least 1 DSC significantly increased odds of SSS, odds ratio >120, P < .0001. Rates of 30-day complications in the SISS group were not significantly different from patients undergoing laminectomy or laminotomy. Rates of 2-year DSC within SISS and cumulative risk associated with these complications should be considered further as they likely represent need for additional procedures for patients and substantial cost to the healthcare system. 4. Having no differences in adverse events between laminectomies or laminotomies and SISS plus evidence of substantial device-specific long-term adverse outcomes and reoperation should be given consideration when deciding on surgical intervention of 1-2 level lumbar spinal stenosis.

Role of pulse plethysmograph in the prediction of hypotension in caesarean section patient under spinal anesthesia

Background: Spinal anesthesia is a commonly employed technique for anesthesia for caesarean section and is associated with hypotension which may cause maternal morbidity. Prediction of hypotension before the procedure can reduce complications. The study aimed to evaluate the role of pulse plethysmograph in the prediction of hypotension in caesarean section patients under spinal anesthesia. Methods: The observational study was conducted on 50 patients who were undergoing emergency or elective caesarean section. Spinal anesthesia was performed by anaesthesiologist using a 25 or 26-gauge spinal needle with bupivacaine at L3-4 interspinous space. Pre and post-anesthesia observations such as the width of pulse plethysmograph, non-invasive blood pressure in another arm, and heart rate were recorded. Paired T-test, Wilcoxon sign rank test, and chi-square test was used to analyse data using R Studio V 1.2.5001 software. Results: Post spinal anesthesia minor fall in systolic blood pressure (SBP) was observed in 11 patients, moderate fall in 21 patients, severe fall in 8 patients and a massive fall in 10 patients. A significant difference was observed between mean pre- and post-spinal anesthesia SBP (P&lt;0.001). Width of pulse plethysmograph (PPG) was maintained in 14 patients whereas, narrowed and significantly narrowed PPGs were observed in 29 and 7 patients, respectively. Significant association was observed between grades of SBP and width of PPG (P&lt;0.05). Receiver operating characteristic curve showed the width of PGG was good for prediction of hypotension in patient (AUC=0.828). Conclusion: Width of PPG can be used to predict SA induced maternal hypotension.

Comparison of three sitting positions for combined spinal - epidural anesthesia: a multicenter randomized controlled trial

Background and objectivesThe aim of this prospective, multi-centered and multi-arm parallel randomized trial was to test the hypothesis that modified sitting positions including hamstring stretch position (HSP) and squatting position (SP) would reduce needle - bone contact events and increase the success rate of combined spinal - epidural anesthesia (CSEA) compared to traditional sitting position (TSP) in patients undergoing total knee or hip arthroplasty. Patients and methodsThree hundred and sixty American Society of Anesthesiologists (ASA) I-III patients, aged between 45-85 years were randomly allocated to one of three groups using computer-generated simple randomization: group TSP (n = 120), group HSP (n = 120), and group SP (n = 120). Primary outcome measures were the number of needle-bone contact and success rates. Secondary outcome measure was the ease of interspinous space identification. ResultsSeven patients in group SP and four of HSP could not tolerate their position and were excluded. Number of needle-bone contact, success rates, and grade of interspinous space identification were similar between groups (p = 1.000). Independent of positioning, the success rates were higher in patients whose interspinous space was graded as easy compared to difficult or impossible (p < 0.001). Success rates reduced, interspinous space identification became more challenging, and number of needle – bone contact increased as patient’s body mass index (BMI) increased (p < 0.001). ConclusionSP and HSP may be used as alternatives to the TSP. BMI and ease of interspinous space identification may be considered important determinants for CSEA success.

Comparing the ease of identifying the subarachnoid space at midline of L3 -L4 interspace by preprocedural ultrasound versus landmark technique - A randomized control study

Introduction: The role of ultrasound in central neuraxial blockade has been underappreciated, partly because of the relative ease of the landmark-guided technique and falsely perceived difficulty in imaging through the narrow acoustic windows. This study was designed to compare conventional landmark technique with preprocedural ultrasonography for identification of the subarachnoid space in patients for elective surgeries under spinal anaesthesia. Materials and Methods: Total 120 patients who were scheduled for elective surgery under spinal anaesthesia were included in this prospective randomised control trial and divided into 2 group, Group L (n = 60) (landmark guided technique) and Group U (n = 60) (ultrasound guided technique). Parameters such as time taken for the identification of the interspace, number of insertion attempts (the primary outcome), number of passes and time taken were recorded in both the groups. Result: The time taken for identification of interspinous space was significantly more in Group U (4.7 ± 2.1 mins) as compared to Group L (1.17 ± 0.52 min) but the number of attempts for needle insertion (1.12 ± 0.41 vs. 1.86 ± 0.91), number of passes in the same interspinous space (3.32 ± 1.44 vs. 6.98 ± 2.51) and the total time for successful lumbar puncture (38.72 ± 12.30 vs. 56.65 ± 11.32 s) were significantly less in Group U as compared to Group L. Conclusion: The ultrasound guided identification of subarachanoid space was time consuming, but resulted in fewer attempts to enter the subarachnoid space when compared to the conventional landmark-based approach. Keywords: Neuraxis, Subarachnoid space, Ultrasonography.

Biomechanical analysis of lumbar spine with interbody fusion surgery and U-shaped lumbar interspinous spacers

Previous research indicates whole-body vibration may lead to low back pain. The aim of this study is assessing the dynamic characteristics of a lumbar spine with Coflex and Coflex-F (commercial implants used as lumbar interspinous spacers) and effect of lumbar interbody fusion surgery. A transient dynamic analysis is performed on three numerical lumbar spine models under the loading condition of a vertical sinusoidal force of ±40 N with a compressive follower preload of 400 N. Also, Coflex-F model with and without interbody fusion surgery is analyzed under the same loading condition. The results show that the maximum value and vibration amplitude of von Mises stress in annulus ground substance (AGS) and intradiscal pressure (IDP) at implanted segment decrease from healthy model to Coflex model, and Coflex-F model. By contrast, for adjacent segments the maximum value of implanted models are larger than that of healthy model. The maximum value of endplates with and without cage are 2.44 MPa and 1.73 MPa (L4 inferior endplate), 1.94 MPa and 1.42 MPa (L5 superior endplate), respectively. The vibration amplitude of Coflex-F model with fusion surgery is smaller than that without fusion surgery. Coflex and Coflex-F not only protect implanted segment but also have a negative effect on adjacent segments. Inserting cage for Coflex-F model can absorb vibration energy at adjacent segments.

Improvement in Neurogenic Pain with Epidural Injections Following Interspinous Spacer Implantation in Patients with Lumbar Stenosis: A Case Series

Background: Lumbar spinal stenosis with neurogenic claudication can be a debilitating condition, affecting quality of life. Interspinous spacer implantation is a minimally invasive procedure for treatment of lumbar spinal stenosis with neurogenic claudication and associated symptoms by minimizing spinal extension and therefore neural compression. Case Presentation: This case series presents 4 cases of patients with multilevel stenosis, most radiographically severe in the lumbar region, all who received interspinous spacers at L3-4 and L4-5 after minimal improvement in symptoms with conservative management including epidural injections. In all 4 cases, patients reported improved standing and gait but limited improvement in pain and overall function after interspinous spacer implantation. Each patient underwent repeat epidural injections at or below the level of the interspinous spacer with significant improvement in pain for up to 6 months. Conclusion: Our conclusion is that either postspacer epidural injections helped reduce inflammation associated with the implantation procedure, or the spacer maintained an open space to allow the injectate to permeate areas with the most stenosis and help reduce inflammation and therefore pain. Key words: Epidural injection, interspinous process decompression, interspinous spacer, interspinous spacer implant, low back pain, lumbar spinal stenosis, neurogenic claudication, spinal stenosis

403 Are You Comfy? Comparing Success Rates of Lumbar Puncture Positions

A lumbar puncture (LP) is commonly performed in the pediatric emergency department for diagnostic purposes; unsuccessful or traumatic LPs can complicate decision making. The sitting position has a larger interspinous space compared to lateral recumbent and is safer in sick neonates at risk for cardiac and respiratory instability. However, few studies have compared the effect of position on LP success and complication rates. The objective of our study was to determine if position affects success rates when performed in infants <3 months old. This is a retrospective chart review in infants aged <3 months who had a LP performed in a pediatric emergency department over a 35-month period. The primary outcome was the rate of successful LPs, defined as obtaining adequate CSF to send for studies. The secondary outcome was the rate of traumatic LPs, defined as >500 RBCs. Summary statistics were calculated and associations were examined using the Wilcoxon rank-sum and Fisher’s exact tests. A total of 557 charts were reviewed, with 116 in the sitting position and 441 in the lateral recumbent position. The primary outcome of adequate CSF fluid collection was not significantly different between groups (63% sitting position versus 58% lateral recumbent position; p = 0.22). In addition, the rate of traumatic LPs showed no significant difference (28% sitting position versus 27% lateral recumbent position; p = 0.84). In secondary analysis (Figure 1), there was a decreased number of LPs with no CSF in the sitting position (0.9%) versus the lateral recumbent position (3.9%), though not statistically significant (p = 0.10). Positioning during a LP in infants <3 months likely does not affect success rates or rates of traumatic LP.

Seated Position Does Not Change Lumbar Dimensions Compared With Lateral Position.

The infant lumbar puncture (LP) can be a technically challenging procedure. Understanding the anatomical lumbar dimensions may optimize LP conditions. Data from preterm neonates, older children, and adults indicate measurements of the lumbar spine in the seated LP position may be superior when compared with the lateral position. We use point-of-care ultrasound (US) to determine if the seated position, when compared with the lateral decubitus position, significantly affected the lumbar dimensions of infants 12 months or younger presenting to the pediatric emergency department. We conducted a prospective observational study of a convenience sample of patients 12 months or younger. We used US to obtain 3 still images oriented longitudinally in the midline over the L3 to L4 interspace in the lateral decubitus and seated positions. A US fellowship-trained emergency physician, blinded to patient position, measured interspinous space, subarachnoid space width, and spinal canal depth. We then compared the means of all 3 dimensions in the lateral and seated positions. From 50 subjects, 49 subjects provided 46 evaluable sets of images for each measure. Interspinous space, spinal canal depth, and subarachnoid space width did not differ significantly between positions. Mean differences did not exceed 0.02 cm for any of the measured dimensions. We report no significant differences in the 3 lumbar dimensions at the seated position when compared with the lateral decubitus position. For infants younger than 12 months, sonographic measurements of lumbar dimensions did not differ between the positions commonly used for LP.

P63. Current incidence of adjacent segment pathology following lumbar fusion versus motion preserving procedures: a systematic review and meta-analysis of recent projections

P63. Current incidence of adjacent segment pathology following lumbar fusion versus motion preserving procedures: a systematic review and meta-analysis of recent projections

Nerve Root Sedimentation Sign: Can It Predict the Success for Surgical Intervention in Patients With Symptomatic Lumbar Spinal Stenosis?

Introduction: The use of interspinous process devices are less invasive surgical methods designed to manage mild to moderate lumbar spinal stenosis symptoms. Symptomatic relief may not be seen in all patients undergoing this procedure. Magnetic resonance imaging (MRI) parameters have been used to predict the success of clinical outcomes in patients with symptomatic lumbar spinal stenosis for decompressive surgeries. The purpose of this study was to determine the feasibility of using nerve root sedimentation sign to predict mid- to long-term clinical outcomes of patients treated with interspinous spacers for lumbar spinal stenosis.Methods: This was a retrospective study using prospective multicenter Food and Drug Administration Investigational Device Exemption (FDA IDE) trial (Superion™ and X-STOP®) data. Inclusion criteria were patients treated with interspinous spacers, aged 45 or older with lumbar spinal stenosis at one or more contiguous levels from L1 to L5 and symptoms of neurogenic claudication. Preoperative axial T2 weighted MRI images were used to determine nerve root sedimentation sign. Preoperative, six-week, one- and two-year postoperative clinical outcomes were measured using Oswestry Disability Index (ODI) scores. Clinical outcomes were compared between positive and negative nerve root sedimentation sign groups; p ≤0.05 was considered significant.Results: This study included n=374 patients; 40 excluded; 334 included (113=positive nerve root sedimentation sign (NRSS) (34%) and 221=negative NRSS (66%)). At six weeks, significant postoperative ODI correction was noted in both groups (p<0.001). No significant differences in ODI scores were identified between groups. A subgroup analysis with MRI image quality grade 3 and certainty determination grade 5, six-week postoperative ODI correction was significant in both groups. Six-week, one- and two-year postoperative ODI scores were greater by 6 points in the positive nerve root sedimentation sign group compared to the negative nerve root sedimentation sign group.Conclusions: Although satisfactory postoperative improvement occurred in both groups, there were statistically significant differences noted in certain sub-categories. The subgroup analysis indicated MRI image quality and nerve root sedimentation sign certainty of determination may be factors that may aid with planning the surgical management of lumbar spinal stenosis.

Haemodynamic Changes &amp; Complications between Unilateral and Bilateral Spinal Anesthesia in Elderly Type-2 Diabetic Patient Undergoing Hemiarthoplasty – A Comparative Study

Background: During spinal anesthesia, extend of sympathetic blockade causes hemodynamic instability,such as hypotension and bradycardia.It can lead to develop cardiac arrest in some cases. Elderly patientdo not compensate these haemodynamic change easily because of aging process leads some physiologicalchanges in all system especially on cardio vascular system e.g; decreased elasticity of vessels, decreasedvascular and myocardial compliance and also decreased autonomic responsiveness. It is hypothesizedthat unilateral spinal anesthesia restrict the spread of hyperbaric bupivacaine to one side only (dependentside) thus sparing the opposite sympathetic chain and hence would cause less haemodynamic changes. Materials &amp; Methods: This cross sectional study, took place in the department of Anaesthesiology andSICU, BIRDEM General Hospital, Shahbag, Dhaka. A total 60 elderly (age-60 to 80 years), ASA grade IIand III, type-2 Diabetic patients scheduled for hemiarthoplasty were enrolled in this study. Patients weredivided into two groups U &amp; A, 30 patients in each. Subarachnoid (spinal) anaesthesia was performed inall patients with 0.5% hyperbaric bupivacaine intrathecally, at L3 - L4 interspinous spaces, with 25GQuinke’s spinal needle. Patients of group U were kept in lateral decubitus position which was maintainedfor 15 minutes after injecting bupivacaine and patients of group B were kept in supine position. Changesof BP, pulse and development of any complication was recorded in 5 minute interval after spinal anesthesia.All the informations were recorded in preformed data collection sheet. Result: Compared with group U, group B showed statistically significant increase inheart rate at 10 minafter spinal anesthesia (p&lt;0.05).Systolic BP was significantly lower in group B compared to group U in allrecorded time interval except at 60 minute.Diastolic blood pressure was significantly lower in group Bcompared to group U at 15, 30 and 45 minute reading. Regarding maen arterial pressure we found it wasreduced significantly in group B compared to group U in all the recorded time except at 60 minute(p&lt;0.05). Present study showed none of the patients in the unilateral group experienced vomiting; onlytwo patients noticed nausea. In the bilateral group, seven patients had nausea and three of them experiencedepisodes of vomiting (p = 0.02). In group U, no case found hypotensive, only single developed bradycardia.In Group B 7 patients experienced hypotensions and 4 patients had bradycardia. Conclusion: This study showed that the unilateral spinal anesthesia reduces the incidence and severityof hypotension, bradycardia and other complication in elderly type-2 diabetic patients. So unilateralspinal anaesthesia is more benifecial for elderly type-2 diabetic patient in hemiarthoplasty. JBSA 2020; 33(2): 62-68

Building block osteotomy, a new back muscle-preserving laminoplasty for lumbar spinal stenosis

In order to preserve paravertebral muscles and posterior ligaments complex (PLC), this paper proposes a new lumbar laminoplasty surgery for lumbar spinal stenosis (LSS). According to the anatomy of back muscles insertions, building block osteotomy (BBO) which aimed to achieve precise osteotomy and reconstruction based on modular design theory was firstly put forward, and supposed to be achieved by an ultrasound bone scalpel (UBS). In details, lumbar spinous processes are longitudinally split, then supraspinous and interspinous ligaments are sharply cut off longitudinally. After converting to lumbar flexion, lamina osteotomy is innovatively finished by an UBS through interspinous space. After decompression, hollow screws are firstly suggested to be used on each side to fix lamina and spinous processes, and PLC is reconstructed by interrupted suture. Feasibility of this method is evaluated in details. Challenges, advantages and disadvantages are also discussed.

Comparison of Ultrasound-Marked Versus Standard Lumbar Puncture Success in Infants.

The aim of this study was to compare ultrasound (US)-marked versus standard lumbar puncture success in infants. This was a prospective cohort study at an academic pediatric emergency department. Standard lumbar puncture success in a retrospective control was compared with success in a US-marked group. Spinal US was performed with infants in the sitting and lateral decubitus position to identify the interspinous space with the most cerebrospinal fluid. The optimal position was determined, and this space was marked. The proceduralist performed the lumbar puncture at the level of the markings. The primary outcome was a successful lumbar puncture by the first provider, defined as a collection of cerebrospinal fluid with less than 1000 red blood cells/mm3. Secondary outcomes were successful lumbar puncture after attempts by more than 1 provider and collection of any spinal fluid. Between June 2017 and April 2019, we enrolled 284 infants younger than 12 months, 210 in the retrospective standard group and 74 in the prospective US-marked group. Baseline characteristics of both groups were similar. The primary outcome showed no difference between US-marked group and control (38% vs 36%; difference: 1.6% [95% confidence interval (CI), -14.7 to 10.7]). Secondary outcomes showed no significant success differences by more than 1 provider (51% vs 39%; difference: 12.8% [95% CI, -25.7 to 0.3]) or in obtaining any spinal fluid (82% vs 79%; difference: 3.9% [95% CI -13.3 to 7.5]). There were no differences in success between US-marked and standard lumbar punctures in infants by different providers.

A New Species of Fairy Wrasse (Teleostei: Labridae: Cirrhilabrus) from Mesophotic Coral Ecosystems of the Verde Island Passage, Philippines

The new species, Cirrhilabrus briangreenei, is described on the basis of the holotype and six paratypes collected from mesophotic coral ecosystems of the Verde Island Passage, Philippines, between depths of 82 and 110 m. The new species is most closely related to Cirrhilabrus pylei, but it differs primarily in the presence of: more pored scales on the posterior lateral line (7–9 vs. 5–6); a lower number of circumpeduncular scales (14 vs. 16); a lower number of gill rakers (16–17 vs. 18–20); and differences in coloration details of the dorsal and caudal fins. Both species differ from all other congeners in sharing the following combination of characters: pelvic fins very long (56.5–70.0% SL), often extending past anal-fin terminus in males; caudal fin scintillating and iridescent in males; dorsal fin with sinuous scribbling in both sexes; anterior dorsal fin with a metallic blue spot on first one to two interspinous membrane spaces; snout with three parallel stripes from maxilla to anterior edge of orbit; and rest of head with a network of short broken pinstripes in both sexes. These characters are also distributed in part amongst other species of Cirrhilabrus, in particular, C. katoi, C. lineatus, C. rhomboidalis, and C. rubrimarginatus, and their putative relationships are discussed on the basis of meristic, morphometric, and molecular sequence data. We briefly comment on the variability of morphological characters within Cirrhilabrus and their implications towards phylogenetic classification, with remarks on methods for data collection for species of Cirrhilabrus.

How I do it: step-by-step BacJac™ posterior interspinous spacer placement.

BacJac™ is a posterior interspinous spacer for selected cases of degenerative lumbar spine diseases. It blocks the metameric vertebral segment in terminal extension, restoring foraminal heights. The authors provide a detailed step-by-step description of the surgical technique, shedding light on surgical tips and pitfalls of this procedure. An accurate pre-operative patient selection is analyzed, defining meticulously surgical indications. A high-quality video of the surgical procedure is provided. BacJac™ interspinous device allows a safe, mini-invasive, and effective treatment of selected cases of degenerative lumbar spine disease.

Successful use of percutaneous interspinous spacers and adjunctive spinoplasty in a 9 year cohort of patients

PurposeLumbar spinal canal stenosis and lumbar spinal foraminal stenosis are common, degenerative pathologies which can result in neurogenic claudication and have a negative impact on function and quality of life....

Ultrasound-assisted subarachnoid block in obese parturient: Need of the hour

Subarachnoid block is commonly used for caesarean deliveries, by virtue of its simplicity in terms of performance and safety for the parturients when compared with general anesthesia. The landmark technique involves palpating the interspinous space at the level of Tuffier's line to ensure the interspace level and direct the spinal needle through optimally selected puncture site for performing the subarachnoid block. However, spinal block is sometimes not easy to perform in obese parturients primarily because of poorly palpable surface landmarks and challenges related to positioning for the block. Recently, ultrasound (USG) is being used for facilitating central neuraxial block, using low-frequency curvilinear probe with encouraging results. We report a case of a 28-year-old, 95-kg parturient, with body mass index of 39.1 kg/m2 scheduled for elective lower segment caesarean section under subarachnoid block, the indication being previous caesarean section. As the landmarks were not appreciable on palpation, we performed USG-assisted preprocedural landmark-based subarachnoid block successfully.

Biomechanics and Mechanism of Action of Indirect Lumbar Decompression and the Evolution of a Stand-alone Spinous Process Spacer.

Objective Objective Interspinous process spacers are used in the treatment of lumbar spinal stenosis by preventing extension at the implanted level and reducing claudication, which is a common symptom of lumbar spinal stenosis. This review assessed the current safety and performance of lumbar spinal stenosis treatments and the biomechanical effects of spinal position, range of motion, and the use of interspinous process spacers.Method Method EMBASE and PubMed were searched to find studies reporting on the safety and performance of nonsurgical treatment, including physical therapy and pharmacological treatment, and surgical treatment, including direct and indirect lumbar decompression treatment. Results were supplemented with manual searches to include studies reporting on the use of interspinous process spacers and the review of biomechanical testing performed on the Superion device.Results Results The effects of spinal position in extension and flexion have been shown to have an impact in the variation in dimensions of the spinal canal and foramina areas. Overall studies have shown that spinal positions from flexion to extension reduce the spinal canal and foramina dimensions and increase ligamentum flavum thickness. Biomechanical test data have shown that the Superion device resists extension and reduces angular movement at the implantation level and provides significant segmental stability.Conclusions Conclusions Superion interspinous lumbar decompression is a minimally invasive, low-risk procedure for the treatment of lumbar spinal stenosis, which has been shown to have a low safety profile by maintaining sagittal alignment, limiting the potential for device dislodgment or migration, and to preserve mobility and structural elements.

Cost-effectiveness and Safety of Interspinous Process Decompression (Superion).

ObjectiveThere are several treatment options for patients suffering from lumbar spinal stenosis, including surgical and conservative care. Interspinous spacer decompression using the Superion device offers a less invasive procedure for patients who fail conservative treatment before traditional decompression surgery. This review assesses the current cost-effectiveness, safety, and performance of lumbar spinal stenosis treatment modalities compared with the Superion interspinous spacer procedure.MethodsEMBASE and PubMed were searched to find studies reporting on the cost-effectiveness, safety, and performance of conservative treatment, including medicinal treatments, epidural injections, physical therapy, and alternative methods, as well as surgical treatment, including laminectomy, laminectomy with fusion, and interspinous spacer decompression. Results were supplemented with manual searches.ResultsDespite substantial costs, persistent conservative treatment (>12 weeks) of lumbar spinal stenosis showed only minimal improvement in pain and functionality. When conservative treatment fails, surgery is more effective than continuing conservative treatment. Lumbar laminectomy with fusion has considerably greater cost than laminectomy alone, as the length of hospital stay increases, the costs for implants are substantial, and complications increase. Although laminectomy and the Superion have comparable outcomes, the Superion implant is positioned percutaneously. This approach may minimize the direct and indirect costs of outpatient rehabilitation and absenteeism, respectively.ConclusionsSuperion interspinous lumbar decompression is a minimally invasive procedure for patients with lumbar spinal stenosis who have failed conservative treatment. Compared with extending conservative treatment or traditional spinal surgery, interspinous lumbar decompression reduces the direct and indirect costs associated with lumbar spinal stenosis.

MRI evaluation of dural sac enlargement by interspinous process spacers in patients with lumbar spinal stenosis: Does it play a role in the long term?

BackgroundTo investigate dural sac enlargements and spinal alignments in patients who underwent indirect decompression with interspinous spacers. MethodsThe subjects were 20 patients who underwent indirect decompression using an interspinous spacer (X-STOP) without laminectomy. Of these 20 patients, 1 patient underwent implant removal surgery 1 month after X-STOP surgery and two patients dropped out. Ultimately, 17 patients were included in this study. MRI and X-ray images were investigated before surgery, 1 week after surgery, 3 months after surgery, and 2 years after surgery. ResultsOn MRI, the mean cross-sectional areas of the dural sac were 52.7 mm2 before surgery, 73.2 mm2 1 week after surgery, 62.4 mm2 3 months after surgery, and 58.3 mm2 2 years after surgery. There was a significant 37% increase at 1 week postoperatively compared with that before surgery, but there were no significant differences between 3 months postoperatively and 2 years postoperatively. The disc angle in an extension posture was significantly decreased at 1 week after surgery compared with that before surgery, but there were no significant differences between before surgery, 3 months after surgery, and 2 years after surgery. ConclusionsThe interspinous process spacer increased the dural sac area by 37% 1 week after surgery, but the enlargement was not maintained at 3 months or 2 years after surgery. The use of interspinous process spacers produced an enlargement of the dural sac by limiting extension of the stenotic level only. However, its effect diminished 2 years after surgery.