Lumbar Spinal Stenosis in Older Adults: Current Understanding and Future Directions

Engineering innovations in medicine and biology: Revolutionizing patient care through mechanical solutions

The overlap between mechanical engineering and medicine is expanding more and more over the years. Engineers are now using their expertise to design and create functional biomaterials and are continually collaborating with physicians to improve patient health. In this review, we explore the state of scientific knowledge in the areas of biomaterials, biomechanics, nanomechanics, and computational fluid dynamics (CFD) in relation to the pharmaceutical and medical industry. Focusing on current research and breakthroughs, we provide an overview of how these fields are being used to create new technologies for medical treatments of human patients. Barriers and constraints in these fields, as well as ways to overcome them, are also described in this review. Finally, the potential for future advances in biomaterials to fundamentally change the current approach to medicine and biology is also discussed.

Correlation between severity of spinal stenosis and multifidus atrophy in degenerative lumbar spinal stenosis

BACKGROUND

Degenerative lumbar spinal stenosis (DLSS) is a common degenerative condition in older adults. Muscle atrophy (MA) is a leading cause of muscle weakness and disability commonly reported in individuals with spinal stenosis. The purpose of this study was to investigate if the MA correlates with the grade of spinal stenosis in patients with DLSS.

METHODS

A retrospective analysis on 48 male and 184 female DLSS patients aged around 54.04 years (54.04 ± 8.93) were involved and divided into 6 groups according to claudication-distance-based grading of spinal stenosis, which confirmed by two independent orthopedic surgeons using T2- weighted images. Using 1.5T MRI scanner, the severity of MA is assessed based on its negative correlation with the ratio of total fat-free multifidus muscle cross-sectional area (TFCSA) to total multifidus muscle cross-sectional area (TCSA). Adobe Photoshop CS6 was used for qualitative image analysis and calculate the TFCSA/TCSA ratio to assess the severity of MA, compare the grade of MA with the spinal stenosis segment, stenosis grade and symptom side.

RESULTS

In DLSS group, The TFCSA/TCSA ratio are 74.33 ± 2.18 in L3/4 stenosis, 75.51 ± 2.79 in L4/5 stenosis, and 75.49 ± 2.69 in L5/S1 stenosis. there were significant decreases in the TFCSA/TCSA ratio of stenotic segments compared with non-stenotic segments of the spinal canal (P < 0.05) while no significant difference between the non-stenotic segments (P > 0.05). TFCSA/TCSA ratios is significant differences in the TFCSA/TCSA ratios of the 6 DLSS groups (F = 67.832; P < 0.05). From Group 1 to Group 6, the TFCSA/TCSA ratio of stenotic segments positively correlated with the absolute claudication distance (ACD). (P < 0.001, r = 0.852). Besides, the TFCSA/TCSA ratios are smaller in the symptomatic sides of the spine than the contralateral sides (t = 4.128, P = 0.001).

CONCLUSIONS

The stenotic segments of the spinal canal are more atrophied than the non-stenotic segment in DLSS patients. It is shows that a strong positive correlation between the severity of multifidus atrophy and the severity of spinal stenosis.

Do Orthopedic Surgeons or Neurosurgeons Detect More Hip Disorders in Patients with Hip-Spine Syndrome? A Nationwide Database Study

Background: Disorders of the hip and lumbar spine can create similar patterns of pain and dysfunction. It is unknown whether all surgeons, regardless of orthopedic or neurosurgery training, investigate and diagnose concurrent hip and spine pathology at the same rate. Methods: Data were retrieved from Taiwan's National Health Insurance Research Database (NHIRD). Enrolled patients were stratified into hip and spine surgery at the same admission (Both), hip surgery before spine surgery (HS), or spine surgery before hip surgery (SH). The SH group was further subdivided based on whether spine surgery was performed by an orthopedic surgeon (OS) or neurosurgeon (NS), and differences in preoperative radiographic examinations and diagnoses were collected and analyzed. Results: In total, 1824 patients received lumbar spine surgery within 1 year before or after hip replacement surgery. Of these, 103 patients had spine and hip surgery in the same admission (Both), 1290 patients had spine surgery before hip surgery (SH), and 431 patients had hip surgery before spine surgery (HS). In the SH group, patients were categorized into spine surgery by orthopedic surgeons (OS) (n = 679) or neurosurgeons (NS) (n = 522). In the SH group, orthopedic surgeons investigated hip pathology with X-rays more often (52.6% vs. 38.1%, p < 0.001) and diagnosed more cases of hip disease (43.6% vs. 28.9%, p < 0.001) than neurosurgeons. Conclusions: Of patients in Taiwan's NHIRD who had concurrent surgical degenerative hip and lumbar spine disorders who had spine surgery before hip surgery, orthopedic surgeons obtained hip images and made hip-related diagnoses more frequently than did neurosurgeons.

Biomechanical effects of laminectomies in the human lumbar spine: a finite element study

BACKGROUND CONTEXT

Previous studies have analyzed the effect of laminectomy on intervertebral disc (IVD), facet-joint-forces (FJF), and range of motion (ROM), while only two have specifically reported stresses at the pars interarticularis (PI) with posterior element resection. These studies have been performed utilizing a single subject, questioning their applications to a broader population.

PURPOSE

We investigate the effect of graded PI resection in a three-dimensional manner on PI stress to provide surgical guidelines for avoidance of iatrogenic instability following lumbar laminectomy. Additionally, quantified FJF and IVD stresses can provide further insight into the development of adjacent segment disease.

STUDY DESIGN

Biomechanical finite element (FE) method investigation of the lumbar spine.

METHODS

FE models of the lumbar spine of three subjects were created using the open-source finite element software, FEBio. Single-level laminectomy, two-level laminectomy, and ventral-to-dorsal PI resection simulations were performed with varying degrees of PI resection from 0% to 75% of the native PI. These models were taken through cardinal ROM under standard loading conditions and PI stresses, FJF, IVD stresses, and ROM were analyzed.

RESULTS

The three types of laminectomy simulated in this study showed a nonlinear increase in PI stress with increased bone resection. Axial rotation generated the most stress at the PI followed by flexion, extension and lateral bending. At 75% bone resection all three types of laminectomy produced PI stresses that were near the ultimate strength of human cortical bone during axial rotation. FJF decreased with increased bone resection for the three laminectomies simulated. This was most notable in axial rotation followed by extension and lateral bending. IVD stresses varied greatly between the nonsurgical models and likewise the effect of laminectomy on IVD stresses varied between subjects. ROM was mostly unaffected by the laminectomies performed in this study.

CONCLUSIONS

Regarding the risk of iatrogenic spondylolisthesis, the combined results are sufficient evidence to suggest surgeons should be particularly cautious when PI resection exceeds 50% bone resection for all laminectomies included in this study. Lastly, the effects seen in FJF and IVD stresses indicate the degree to which the remainder of the spine must experience compensatory biomechanical changes as a result of the surgical intervention.

Rate of radiographic hip OA in spine patients: utility of including femoral heads on plain film A/P lumbar radiographs

The incidence of concomitant lumbar spine and hip pathology is common in referral patients to spine clinics. Differentiating between the two pathologies is a key component to the clinical practitioner's role. At our institution, it has become routine protocol to obtain radiographs including the femoroacetabular joints on the AP and lateral views of the lumbar spine as part of the initial workup. The purpose of this study was to determine the rates of radiographic hip pathology seen on lumbar spine imaging. We report just over 25% concomitant spine and hip pathology with 25% of patients requiring further management from a hip surgeon. The studied protocol will assist in the workup of spine patients to further differentiate the intricacies of hip- and spine-related pathology.

"Tube in tube" interlaminar endoscopic decompression for the treatment of lumbar spinal stenosis: Technique notes and preliminary clinical outcomes of case series

To describe the Tube in Tube interlaminar endoscopic decompression method and investigate its efficacy and safety in treating lumbar spinal stenosis (LSS).Utilizing the advantages of the micro-endoscopic decompression (MED) operation channel tube, we used a water-medium spinal endoscopy to perform trans-interlaminar canal decompression, that is, the "Tube in Tube" technique. A retrospective study was performed on 35 patients with LSS who were treated with the Tube in Tube technique. All patients were followed up to 12 months postoperatively. Visual analog scale (VAS), Japanese Orthopaedic Association (JOA) score, and Oswestry Disability Index (ODI) were collected preoperatively and at 3, 6, and 12 months postoperatively. Short-form (36) health survey (SF-36) score was used to examine the general health-related quality of life (HRQoL) of patients preoperatively and at 3 and 12 months postoperatively. Modified Macnab criteria were used to examine the clinical outcomes at 3 and 12 months post-surgery.The clinical outcomes were satisfactory, with an improvement in all scoring systems. The VAS, JOA, and ODI scores improved from 6.46 ± 1.85, 12.03 ± 4.96, and 42.17 ± 12.22 preoperatively to 2.20 ± 1.14, 21.40 ± 5.86, and 13.14 ± 7.52 at 12 months postoperatively, respectively (P < .001). The Macnab excellent or good rates reached 65.7% and 77.1% at the 3 and 12 months follow-ups. No severe complications occurred.The Tube in Tube technique had a positive clinical outcome in LSS patients and is safe, reliable, and efficacious. However, a larger number of cases and a multi-center research design will be needed further develop the technique.Level of Evidence: IV.

Effects of SHINBARO2 on Rat Models of Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) is a major cause of chronic low back pain; however, only a few therapies which have been used in clinics still have limited effects on functional recovery. SHINBARO2 is a refined traditional formulation for inflamed lesions and relieve pain of muscular skeletal disease. This study aimed at investigating the effects of SHINBARO2 on LSS and at determining its underlying molecular mechanism in rat models. The LSS rat models were set up by surgical operations in 6-week-old male Sprague-Dawley rats. SHINBARO2 was orally or intraperitoneally administered for 14 days. The motor and sensory ability of rats were evaluated using the activity cage and hot plate method. On the termination day, total vertebrae including the disc and spinal cord were excised for ex vivo study. SHINBARO2 improved locomotor functions and pain sensitivity in LSS rat models. Mechanism study suggested that SHINBARO2 inhibited the production of nitric oxide and prostaglandin E₂ in tissues from LSS-induced rats. SHINBARO2 also suppressed the expression of proinflammatory cytokines including tumor necrosis factor-α and interleukin-1β. The activation of NF-κB by LSS surgery was effectively reduced by SHINBARO2, which coincided with the inhibition of IκB degradation. In addition, brain-derived neurotrophic factor (BDNF), a potent promoter of neurite growth, and its downstream ERK signaling were also regulated by SHINBARO2. These findings suggest that the effect of SHINBARO2 might be associated in part with the anti-inflammation and pain control in LSS rat models.

Comparison of two FDA-approved interspinous spacers for treatment of lumbar spinal stenosis: Superion versus X-STOP-a meta-analysis from five randomized controlled trial studies

BACKGROUND

Decompressive laminectomy (DI) is a standard operation for lumbar spinal stenosis (LSS) patient with severe claudication symptoms for many years. However, patients whose symptom severity does not meet undergoing invasive surgery make therapeutic options into dilemma. Interspinous spacers (ISP) bridge the gap between surgical interventions and CC in management of LSS. In our study, we aim to systematically assess the two FDA-approved interspinous spacers for treatment of lumbar spinal stenosis: Superion versus X-STOP.

METHODS

Electronic databases, including PubMed, Embase, MEDLINE, Cochrane Library were searched to retrieve clinical trials concerning the comparison between Superion and X-STOP in treatment for lumbar spinal stenosis before April 2017. The following outcome measures were extracted: (1) Zurich Claudication Questionnaire (ZCQ) patient satisfaction score, (2) axial pain severity, (3) extremity pain severity, (4) back-specific functional impairment, (5) reoperation, and (6) complication. The data analysis was conducted with Review Manager 5.3.

RESULTS

Five randomized controlled trials (RCTs) with 1118 patients were included in this meta-analysis. The pooled analysis indicated that the Superion group is superior to X-STOP in axial pain severity (SMD: 0.03; 95% CI 0.15, 0.45; p < 0.0001, I² = 41%, p = 0.16), ZCQ patient satisfaction score (SMD: 0.23; 95% CI 0.08, 0.38; p = 0.002, I² = 0%, p = 0.61). However, Superion group showed similarity outcome in extremity pain severity (SMD: 0.18; 95% CI - 0.06, 0.43; p = 0.14, I² = 62%, p = 0.05), back-specific functional impairment (SMD: 0.04; 95% CI - 0.10, 0.19; p = 0.56, I² = 0%, p = 0.77), reoperation rate (RR: 1.10; 95% CI 0.82, 1.48; p = 0.51, I² = 19%, p = 0.30), and complication (RR: 0.98; 95% CI 0.63, 1.53; p = 0.92, I² = 0%, p = 0.83).

CONCLUSION

Both the Superion and X-STOP interspinous spacers can relieve symptoms of LSS. In addition, the Superion spacer may represent a promising spacer for patient with LSS. As we know, the effectiveness and safety of ISP is still considered investigational and unfavor clinical results in the medical literature may continue to limit the appeal of IPS to many surgeons in the future. However, because of the advantage of IPS technique, it will win a wide place in the future degenerative lumbar microsurgery.

Magnetic Resonance Imaging in Patients With Mechanical Low Back Pain Using a Novel Rapid-Acquisition Three-Dimensional SPACE Sequence at 1.5-T: A Pilot Study Comparing Lumbar Stenosis Assessment With Routine Two-Dimensional Magnetic Resonance Sequences

PURPOSE

To minimize the burden of overutilisation of lumbar spine magnetic resonance imaging (MRI) on a resource-constrained public healthcare system, it may be helpful to image some patients with mechanical low-back pain (LBP) using a simplified rapid MRI screening protocol at 1.5-T. A rapid-acquisition 3-dimensional (3D) SPACE (Sampling Perfection with Application-optimized Contrasts using different flip angle Evolution) sequence can demonstrate common etiologies of LBP. We compared lumbar spinal canal stenosis (LSCS) and neural foraminal stenosis (LNFS) assessment on 3D SPACE against conventional 2-dimensional (2D) MRI.

METHODS

We prospectively performed 3D SPACE and 2D spin-echo MRI sequences (axial or sagittal T1-weighted or T2-weighted) at 1.5-T in 20 patients. Two blinded readers assessed levels L3-4, L4-5 and L5-S1 using: 1) morphologic grading systems, 2) global impression on the presence or absence of clinically significant stenosis (n = 60 disc levels for LSCS, n = 120 foramina for LNFS). Reliability statistics were calculated.

RESULTS

Acquisition time was ∼5 minutes for SPACE and ∼20 minutes for 2D MRI sequences. Interobserver agreement of LSCS was substantial to near perfect on both sequences (morphologic grading: kappa [k] = 0.71 SPACE, k = 0.69 T2-weighted; global impression: k = 0.85 SPACE, k = 0.78 T2-weighted). LNFS assessment had superior interobserver reliability using SPACE than T1-weighted (k = 0.54 vs 0.37). Intersequence agreement of findings between SPACE and 2D MRI was substantial to near perfect by global impression (LSCS: k = 0.78 Reader 1, k = 0.85 Reader 2; LNFS: k = 0.63 Reader 1, k = 0.66 Reader 2).

CONCLUSIONS

3D SPACE was acquired in one-quarter the time as the conventional 2D MRI protocol, had excellent agreement with 2D MRI for stenosis assessment, and had interobserver reliability superior to 2D MRI. These results justify future work to explore the role of 3D SPACE in a rapid MRI screening protocol at 1.5-T for mechanical LBP.

UNILATERAL LAMINOTOMY FOR BILATERAL MICRODECOMPRESSION OF STENOSIS OF THE LUMBAR CANAL

With the aging of the world population, the treatment of stenosis of the lumbar canal has become an important issue in addressing degenerative diseases of the spine. The prevalence of this disease tends to increase as the number of surgeries and the impact on health care costs. This paper aims to describe in detail the technique of unilateral laminotomy for bilateral microdecompression (ULBM) of stenosis of the lumbar canal (LSC) and current clinical results, including their advantages, disadvantages and common complications, based on the available literature. Important studies have shown evidence that surgical treatment for LSC is more effective than the conservative, but without evaluating ULBM. Several studies on ULBM have been conducted since the 90s, showing the results of this technique, however, most of these are case series, retrospective studies or cohorts without proper control group or with weak statistical analysis to prove some evidence. A double-blind randomized clinical trial was found, but with short follow-up. We conclude that studies are needed with more solid evidence to prove the effectiveness of ULBM despite the clinical results being similar to those of classical surgery found in the literature.

Lumbar Spinal Canal Stenosis Classification Criteria: A New Tool

Study Design

Case-control study.

Purpose

To design a new tool for classifying lumbar spinal canal stenosis (CLSCS).

Overview of Literature

Grading of patients with lumbar spinal canal stenosis (LSCS) is controversial.

Methods

The Oswestry disability index (ODI) and the neurogenic claudication outcome score (NCOS) were recorded. Four parameters, which indicate the severity of LSCS disease, including Hufschmidt-grade, grading of magnetic resonance imaging, self-paced walking test, and stenosis ratio (SR) were employed. For the SR, quartile analysis was applied for classifying LSCS and the Hufschmidt-grade was modified into a 4-grade score. An initial score was assigned to each metric based on the severity of LSCS. Using the inverse-variance weighting method, the relative weights of these domains and their categories were determined. The score for all of the cases was obtained based on their weight by summing up the points of the four variables. Quartile analysis was used and a CLSCS score was proposed. Finally, intra- and interobserver reliability, and validity were assessed.

Results

A total of 357 patients were studied. The final CLSCS score for each case ranged from 4 to 16.5. Based on the quartile analysis, using the new criteria set, the CLSCS score was divided into four categories: CLSCS<7 (grade 0); 7≤CLSCS<10 (grade 1); 10≤CLSCS<13 (grade 2); and 13≤CLSCS≤16.5 (grade 3). The kappa values of for the CLSCS score indicated a perfect agreement. The CLSCS was correlated with the ODI and NCOS. All patients with grade 3 CLSCS were observed in the surgical group.

Conclusions

The CLSCS score can be helpful for classifying LSCS patients and in the decision-making process.

Two-year clinical outcomes of a multicenter randomized controlled trial comparing two interspinous spacers for treatment of moderate lumbar spinal stenosis

BACKGROUND

Interspinous spacers are a minimally invasive surgical alternative for patients with lumbar spinal stenosis (LSS) unresponsive to conservative care. The purpose of this prospective, multicenter, randomized, controlled trial was to compare 2-year clinical outcomes in patients with moderate LSS treated with the Superion(®) (Experimental) or the X-Stop(®), a FDA-approved interspinous spacer (Control).

METHODS

A total of 250 patients with moderate LSS unresponsive to conservative care were randomly allocated to treatment with the Experimental (n = 123) or Control (n = 127) interspinous spacer and followed through 2 years post-treatment. Complication data were available for all patients and patient-reported outcomes were available for 192 patients (101 Experimental, 91 Control) at 2 years.

RESULTS

Zurich Claudication Questionnaire (ZCQ) Symptom Severity and Physical Function scores improved 34% to 36% in both groups through 2 years (all p < 0.001). Patient Satisfaction scores at 2 years were 1.8 ± 0.9 with Experimental and 1.6 ± 0.8 with Control. Axial pain decreased from 59 ± 26 mm at baseline to 21 ± 26 mm at 2 years with Experimental and from 55 ± 26 mm to 21 ± 25 mm with Control (both p < 0.001). Extremity pain decreased from 67 ± 24 mm to 14 ± 22 mm at 2 years with Experimental and from 63 ± 24 mm to 18 ± 23 mm with Control (both p < 0.001). Back function assessed with the Oswestry Disability Index similarly improved with Experimental (37 ± 12% to 18 ± 16%) and Control (39 ± 12% to 20 ± 16%) (both p < 0.001). Freedom from reoperation at the index level was 84% for Experimental and 83% for Control (log-rank: p = 0.38) at 2 years.

CONCLUSIONS

Both interspinous spacers effectively alleviated pain and improved back function to a similar degree through 2 years in patients with moderate LSS who were unresponsive to conservative care.

TRIAL REGISTRATION

NCT00692276.

Lumbar spinal stenosis: therapeutic options review

Lumbar spinal stenosis (LSS) functionally impacts significant numbers of Americans per year. Current estimates place the number of Americans suffering from senescent lumbar spinal stenosis at 400,000. The prevalence of this disorder in patients ranging from 60 to 69 years of age is very high. Forty-seven percent of this age group have mild to moderate stenosis, and 19.7% have severe stenosis. As the baby boomer generation gets older, 10,000 individuals attain the age of 65 years every day in United States. LSS is becoming very common and will be a major healthcare issue as the population ages. Although LSS is not life threatening, it can cause substantial disability with limitations to performing daily activities, and thus, the associated negative impact on quality of life (QOL). This article reviews the pathophysiology and current treatment options for LSS, focusing on evidence-based treatment options.

Use of artificial neural networks to predict surgical satisfaction in patients with lumbar spinal canal stenosis

Object

The purpose of this study was to develop an artificial neural network (ANN) model for predicting 2-year surgical satisfaction, and to compare the new model with traditional predictive tools in patients with lumbar spinal canal stenosis.

Methods

The 2 prediction models included an ANN and a logistic regression (LR) model. The patient age, sex, duration of symptoms, walking distance, visual analog scale scores of leg pain or numbness, the Japanese Orthopaedic Association score, the Neurogenic Claudication Outcome Score, and the stenosis ratio values were determined as the input variables for the ANN and LR models that were developed. Patient surgical satisfaction was recorded using a standardized measure. The ANNs were fed patient data to predict 2-year surgical satisfaction based on several input variables. Sensitivity analysis was applied to the ANN model to identify the important variables. The receiver operating characteristic–area under curve (ROC-AUC), Hosmer-Lemeshow statistics, and accuracy rate were calculated for evaluating the 2 models.

Results

A total of 168 patients (59 male, 109 female; mean age 59.8 ± 11.6 years) were divided into training (n = 84), testing (n = 42), and validation (n = 42) data sets. Postsurgical satisfaction was 88.7% at 2-year follow-up. The stenosis ratio was the important variable selected by the ANN. The ANN model displayed a better accuracy rate in 96.9% of patients, a better Hosmer-Lemeshow statistic in 42.4% of patients, and a better ROC-AUC in 80% of patients, compared with the LR model.

Conclusions

The findings show that an ANN can predict 2-year surgical satisfaction for use in clinical application and is more accurate compared with an LR model.

Hip-spine syndrome

The incidence of symptomatic osteoarthritis of the hip and degenerative lumbar spinal stenosis is increasing in our aging population. Because the subjective complaints can be similar, it is often difficult to differentiate intra- and extra-articular hip pathology from degenerative lumbar spinal stenosis. These conditions can present concurrently, which makes it challenging to determine the predominant underlying pain generator. A thorough history and physical examination, coupled with selective diagnostic testing, can be performed to differentiate between these clinical entities and help prioritize management. Determining the potential benefit from surgical intervention and the order in which to address these conditions are of utmost importance for patient satisfaction and adequate relief of symptoms.

Interspinous spacer implant in patients with lumbar spinal stenosis: preliminary results of a multicenter, randomized, controlled trial

A prospective, randomized, controlled trial was conducted to compare clinical outcomes in patients treated with an investigational interspinous spacer (Superion) versus those treated with an FDA-approved spacer (X-STOP). One hundred sixty-six patients with moderate lumbar spinal stenosis (LSS) unresponsive to conservative care were treated randomly with the Superion (n = 80) or X-STOP (n = 86) interspinous spacer. Study subjects were followed through 6 months posttreatment. Zurich Claudication Questionnaire (ZCQ) symptom severity scores improved 30% with Superion and 25% with X-STOP (both P < 0.001). Similar changes were noted in ZCQ physical function with improvements of 32% with Superion and 27% with X-STOP (both P < 0.001). Mean ZCQ patient satisfaction score ranged from 1.7 to 2.0 in both groups at all follow-up visits. The proportion of subjects that achieved at least two of three ZCQ clinical success criteria at 6 months was 75% with Superion and 67% with X-STOP. Axial pain decreased from 55 ± 27 mm at pretreatment to 22 ± 26 mm at 6 months in the Superion group (P < 0.001) and from 54 ± 29 mm to 32 ± 31 mm with X-STOP (P < 0.001). Extremity pain decreased from 61 ± 26 mm at pretreatment to 18 ± 27 mm at 6 months in the Superion group (P < 0.001) and from 64 ± 26 mm to 22 ± 30 mm with X-STOP (P < 0.001). Back function improved from 38 ± 13% to 21 ± 19% with Superion (P < 0.001) and from 40 ± 13% to 25 ± 16% with X-STOP (P < 0.001). Preliminary results suggest that the Superion interspinous spacer and the X-STOP each effectively alleviate pain and improve back function in patients with moderate LSS who are unresponsive to conservative care.

Minimally invasive treatment of moderate lumbar spinal stenosis with the superion interspinous spacer

PURPOSE

We evaluated the safety and effectiveness of the minimally invasive Superion(®) Interspinous Spacer (VertiFlex, Inc., San Clemente, CA) in patients with moderate LSS.

METHODS

This single-arm prospective study enrolled 121 patients with moderate LSS between February 2008 and August 2009 and were followed up at 1 (n=111), 3 (n=96), 6 (n=81), and 12 (n=52) months. All patients were treated with the Superion Interspinous Spacer. Main outcomes were back function with the Oswestry Disability Index (ODI), extremity and axial pain severity with an 11-point scale, health-related quality of life with the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-36, and adverse events through 12 months.

RESULTS

ODI improved 64% (p<0.001) through 12 months and clinical success was 92%. Extremity and axial pain improved 53% and 49% (both p<0.001), respectively, through 12 months with clinical success of 76% for axial pain and 86% for extremity pain. Health-related quality of life improved 41% for PCS and 22% for MCS (both p<0.001) through 12 months. PCS clinical success was 81% and MCS clinical success was 62% at 12 months. Four (5.9%) explants were performed although 3 were unrelated to the device. Eight procedure-related adverse events, observed in 6 (5.0%) patients, included superficial incision seroma (n=5), minor wound pain (n=2), and infection (n=1).

CONCLUSIONS

Preliminary results with the Superion Interspinous Spacer suggest that it is an effective and safe treatment option for patients with moderate LSS who are unresponsive to conservative care.

Minimally invasive treatment of lumbar spinal stenosis with a novel interspinous spacer

Purpose

To assess the safety and effectiveness of a novel, minimally invasive interspinous spacer in patients with moderate lumbar spinal stenosis (LSS).

Methods

A total of 53 patients (mean age, 70 ± 11 years; 45% female) with intermittent neurogenic claudication secondary to moderate LSS, confirmed on imaging studies, were treated with the Superion^® Interspinous Spacer (VertiFlex, Inc, San Clemente, CA) and returned for follow-up visits at 6 weeks, 1 year, and 2 years. Study endpoints included axial and extremity pain severity with an 11-point numeric scale, Zurich Claudication Questionnaire (ZCQ), back function with the Oswestry Disability Index (ODI), health-related quality of life with the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-12, and adverse events.

Results

Axial and extremity pain each decreased 54% (both P < 0.001) over the 2-year follow-up period. ZCQ symptom severity scores improved 43% (P < 0.001) and ZCQ physical function improved 44% (P < 0.001) from pre-treatment to 2 years post-treatment. A statistically significant 50% improvement (P < 0.001) also was noted in back function. PCS and MCS each improved 40% (both P < 0.001) from pre-treatment to 2 years. Clinical success rates at 2 years were 83%–89% for ZCQ subscores, 75% for ODI, 78% for PCS, and 80% for MCS. No device infection, implant breakage, migration, or pull-out was observed, although two (3.8%) patients underwent explant with subsequent laminectomy.

Conclusion

Moderate LSS can be effectively treated with a minimally invasive interspinous spacer. This device is appropriate for select patients who have failed nonoperative treatment measures for LSS and meet strict anatomical criteria.

A new grading system of lumbar central canal stenosis on MRI: an easy and reliable method

OBJECTIVE

To introduce a new grading system of lumbar central canal stenosis, evaluate its reliabilities, and compare it to the cross-sectional area and anterior-posterior diameter of the dural sac.

MATERIALS AND METHODS

Lumbar central canal stenosis is defined as obliteration of the anterior CSF space in front of the cauda equina. Four musculoskeletal radiologists independently graded lumbar central canal stenosis by this new grading system based on separation degree of the cauda equina on T2-weighted axial images (grade 0 = no lumbar stenosis without obliteration of anterior CSF space; grade 1 = mild stenosis with separation of all cauda equina; grade 2 = moderate stenosis with some cauda equina aggregated; and grade 3 = severe stenosis with none of the cauda equina separated) in 81 patients to determine inter- and intra-reader reliability. One radiologist measured cross-sectional areas and anterior-posterior diameters and compared these to lumbar central canal stenosis grades.

RESULTS

Inter-reader reliabilities were substantial to almost perfect (ICC reliability = 0.730-0.953). Intra-reader reliability was almost perfect (kappa value = 0.863-0.900). Cross-sectional areas and anterior-posterior diameters were different according to grades at all levels (p = 0.000-0.049), except between grades 2 and 3 of L2-3. At L5-S1, only anterior-posterior diameter was different between grades 0 and 1 (p = 0.005) and between grades 0 and 2 (p = 0.022).

CONCLUSIONS

This new grading system may be helpful to clinicians for simple and practical evaluation of lumbar central canal stenosis and for communicating with each other.

Steroids in regional analgesia

IMPORTANCE OF THE FIELD

Local injections of steroids have been widely practiced to provide regional analgesia for the treatment of a wide variety of musculoskeletal pain syndromes. However, evidence regarding the effectiveness of steroid injections is not substantial. Also, there have been reports of catastrophic complications associated with their use.

AREAS COVERED IN THIS REVIEW

The evidence currently available in the literature (Database: Ovid MEDLINE 1950 to 2010) is reviewed. The areas covered include the analgesic mechanisms of steroids, indications for steroid injections and their effectiveness, as well as the risks and precautions for steroid injections.

WHAT THE READER WILL GAIN

This is an up-to-date review on the clinical application of steroid injections for regional analgesia, which will give the reader an insight on how to maximize the benefits of steroids while minimizing their side effects and complications.

TAKE HOME MESSAGE

Although steroid injections are generally considered effective and safe in the treatment of painful condition of limbs, their use in the treatment of chronic back pain is still controversial and serious complications have been reported. More studies on outcome and safety are warranted.

Chronic Low Back Pain Among Older Adults: A Population-Based Perspective

Objectives: To determine the prevalence of chronic low back pain (LBP) in older North Carolinians, describe their health and health care utilization, and compare these findings with younger subgroups. Method: A cross-sectional, telephone survey of 5,357 households was conducted to identify 732 adults with chronic, impairing LBP. Results: Chronic LBP prevalence in older adults was significantly higher than the 21-to-44-year age group (12.3% vs. 6.5%, p < .001). Older adults were more disabled, had longer symptom duration, and were less depressed. Chronic LBP care seeking in older adults was significantly lower than the 45-to-64-year age group (80.6% vs. 88.6%, p = .02). Older adults were less likely to receive bed rest, spinal manipulation, heat/cold treatments, electrical stimulation, and massage therapy. Use of nonsteroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, strong narcotics, and antidepressants was significantly lower in the older age group. Discussion: There are age-related differences in health and health care use among individuals with chronic LBP.

Lumbar spinal stenosis: a brief review of the nonsurgical management

PURPOSE

The purpose of this brief narrative review is to summarize the evidence derived from randomized controlled trials pertaining to the nonsurgical treatment of lumbar spinal stenosis (LSS).

SOURCE

The MEDLINE (January 1950 to the fourth week of January 2010) and EMBASE (January 1980 to 2009, week 53) databases, the MESH term "spinal stenosis", and the key words, "vertebral canal stenosis" and "neurogenic claudication", were searched. Results were limited to randomized controlled trials (RCTs) conducted on human subjects, written in English, and published in peer-reviewed journals. Only RCTs pertaining to nonsurgical treatment were considered. Studies comparing conservative and surgical management or different surgical techniques were not included in the review.

PRINCIPAL FINDINGS

The search criteria yielded 13 RCTs. The average enrolment was 54 subjects per study. Blinded assessment and sample size justification were provided in 85% and 39% of RCTs, respectively. The available evidence suggests that parenteral calcitonin, but not intranasal calcitonin, can transiently decrease pain in patients with LSS. In the setting of epidural blocks, local anesthetics can improve pain and function, but the benefits seem short-lived. The available evidence does not support the addition of steroids to local anesthetic agents. Based on the limited evidence, passive physical therapy seems to provide minimal benefits in LSS. The optimal regimen for active physiotherapy remains unknown. Although benefits have been reported with gabapentin, limaprost, methylcobalamin, and epidural adhesiolysis, further trials are required to validate these findings.

CONCLUSIONS

Because of their variable quality, published RCTs can provide only limited evidence to formulate recommendations pertaining to the nonsurgical treatment of LSS. In this narrative review, no study was excluded based on factors such as sample size justification, statistical power, blinding, definition of intervention allocation, or clinical outcomes. This aspect may represent a limitation as it may serve to overemphasize evidence derived from "weaker" trials. Further well-designed RCTs are warranted.

Psychometric properties of commonly used low back disability questionnaires: are they useful for older adults with low back pain?

OBJECTIVES

To evaluate the psychometric properties of two commonly used low back pain (LBP) disability questionnaires in a sample solely comprising community-dwelling older adults.

DESIGN

Single-group repeated measures design.

SETTING

Four continuing care retirement communities in Maryland and in Virginia. Participants. Convenience sample of 107 community-dwelling men and women (71.9%) aged 62 years or older with current LBP. Outcome Measures. All participants completed modified Oswestry Disability (mOSW) and Quebec Back Pain Disability (QUE) questionnaires, as well as the Medical Outcomes Survey Short-Form 36 questionnaire at baseline. At follow-up, 56 participants completed the mOSW and the QUE for reliability assessment.

RESULTS

Test-retest reliability of the mOSW and QUE were excellent with intraclass correlation coefficients of 0.92 (95% confidence interval [CI]: 0.86, 0.95) and 0.94 (95% CI: 0.90, 0.97), respectively. Participants with high pain severity and high levels of functional limitation had higher scores on the mOSW (P < 0.0001) and QUE (P < 0.001) scales than other participants, which represents good construct validity for both scales. The threshold for minimum detectable change is 10.66 points for the mOSW and 11.04 points for the QUE. Both questionnaires had sufficient scale width to accurately measure changes in patient status.

CONCLUSIONS

It appears that both questionnaires have excellent test-retest reliability and good construct validity when used to evaluate LBP-related disability for older adults with varying degrees of LBP. Neither questionnaire appears to have superior psychometric properties; therefore, both the Oswestry and Quebec can be recommended for use among geriatric patients with LBP.