Lumbar Spinal Canal Stenosis Research Articles

Commentary to the article: “Clinicoradiological assessment of lumbar spinal canal stenosis and evaluation of its surgical treatment”

Commentary to the article: “Clinicoradiological assessment of lumbar spinal canal stenosis and evaluation of its surgical treatment”

Surgical outcomes of the thoracic ossification of ligamentum flavum: A high incidence of combined spinal stenosis

The term “tandem spinal stenosis (TSS)” has been used to describe combined cervical and lumbar canal stenosis. We identified in our large series of cases that approximately 58% of cases with cervical canal stenosis were considered to be TSS, and 15% needed surgery for concurrent lumbar spinal canal stenosis (LCS)

New diagnostic support tool for lumbosacral foraminal stenosis using radiographs of the lumbar spine

Detection of lumbar foraminal stenosis (LFS) is difficult using common diagnostic methods, resulting in poor outcomes after lumbar spine surgery. This study aimed to develop a new support tool to detect lumbosacral foraminal stenosis. At our hospital, the following parameters were examined on standing radiographs of the lumbar spine in 100 patients who underwent surgery for lumbar spinal canal and/or foraminal stenosis: 1) presence or absence of the inclination of L5 toward the symptomatic side, 2) distance between the pedicle of L5 and S1, 3) width of the transverse process of L5, 4) distance between the transverse process of L5 and the sacral ala, 5) length of the lateral osteophyte of L5, 6) lumbosacral angle, 7) disc height of L5-S1, and 8) presence or absence of spondylolisthesis of L5. Logistic regression analysis, using cut-off values calculated by receiver operating characteristic (ROC) curve analysis, indicated that the presence of inclination in L5, length of the lateral osteophyte (≥4 mm), distance between the transverse process of L5 and the sacral ala (≤9 mm), and disc height of L5-S1 (≤5 mm) were significantly related to LFS at L5-S1 with odds ratios of 29.07, 38.83, 5.04, and 27.84, respectively. The p-value of the support tool, consisting of the odds ratios above, was 0.724 as per the Hosmer-Lemeshow analysis. ROC analysis demonstrated a cut-off value of 62 for this scoring system with 98% sensitivity and 80% specificity. Hence, we propose that this support tool could be reliably used in clinical practice.

Hypertrophy of the ligamentum flavum in lumbar spinal canal stenosis is associated with abnormal accumulation of specific lipids

Ligamentum flavum hypertrophy (HLF) is the most important component of lumbar spinal canal stenosis (LSCS). Analysis of hypertrophied ligamentum flavum (HLF) samples from patients with LSCS can be an important que. The current study analyzed the surgical samples of HLF samples in patients with LCSC using quantitative and qualitative high performance-liquid chromatography and mass spectrometry. We collected ligamentum flavum (LF) tissue from twelve patients with LSCS and from four patients with lumbar disk herniation (LDH). We defined LF from LSCS patients as HLF and that from LDH patients as non-hypertrophied ligamentum flavum (NHLF). Total lipids were extracted from the LF samples and evaluated for quantity and quality using liquid chromatography and mass spectrometry. The total lipid amount of the HLF group was 3.6 times higher than that of the NHLF group. Phosphatidylcholines (PCs), ceramides (Cers), O-acyl-ω-hydroxy fatty acids (OAHFAs), and triglycerides (TGs) in the HLF group were more than 32 times higher than those of the NHLF group. PC(26:0)+H+, PC(25:0)+H+, and PC(23:0)+H+ increased in all patients in the HLF group compared to the NHLF group. The thickness of the LF correlated significantly with PC(26:0)+H+ in HLF. We identified the enriched specific PCs, Cers, OAHFAs, and TGs in HLF.

Comparison between microendoscopic laminectomy and open posterior decompression surgery for single-level lumbar spinal stenosis: a multicenter retrospective cohort study

BackgroundMicroendoscopic laminectomy (MEL), in which a 16-mm tubular retractor with an internal scope is used, has shown excellent surgical results for patients with lumbar spinal canal stenosis. However, no reports have directly compared MEL with open laminectomy. This study aimed to elucidate patient-reported outcomes (PROs) and perioperative complications in patients undergoing MEL versus open laminectomy.MethodsThis is a multicenter retrospective cohort study of prospectively registered patients who underwent lumbar spinal surgery at one of the six high-volume spine centers between April 2017 and September 2018. A total of 258 patients who underwent single posterior lumbar decompression at L4/L5 were enrolled in the study. With regard to demographic data, we prospectively used chart sheets to evaluate the diagnosis, operative procedure, operation time, estimated blood loss, and complications. The follow-up period was 1-year. PROs included a numerical rating scale (NRS) for lower back pain and leg pain, the Oswestry Disability Index (ODI), EuroQol 5 Dimension (EQ-5D), and patient satisfaction with the treatment.ResultsOf the 258 patients enrolled, 252 (97%) completed the 1-year follow-up. Of the 252, 130 underwent MEL (MEL group) and 122 underwent open decompression (open group). The MEL group required a significantly shorter operating time and sustained lesser intraoperative blood loss compared with the open group. The MEL group showed shorter length of postoperative hospitalization than the open group. The overall complication rate was similar (8.2% in the MEL group versus 7.7% in the open group), and the revision rate did not significantly differ. As for PROs, both preoperative and postoperative values did not significantly differ between the two groups. However, the satisfaction rate was higher in the MEL group (74%) than in the open group (53%) (p = 0.02).ConclusionsMEL required a significantly shorter operating time and resulted in lesser intraoperative blood loss compared with laminectomy. Postoperative PROs and complication rates were not significantly different between the procedures, although MEL demonstrated a better satisfaction rate.

Full-Endoscopic Trans-Kambin Triangle Lumbar Interbody Fusion: Surgical Technique and Nomenclature.

Full-endoscopic lumbar surgery is used for decompression of lumbar spinal canal stenosis. Now, a cage can be inserted through Kambin's triangle for lumbar interbody fusion (LIF). We have been performing full-endoscopic trans-Kambin triangle LIF (KLIF) at our institution since 2018. In this article, we describe this technique and present our results. We performed full-endoscopic one-level KLIF in 10 patients. The procedure is as follows. First, percutaneous pedicle screws are inserted. Listhesis is reduced if necessary. The endoscope is inserted in Kambin's triangle. Next, the superior articular process is partially removed, enlarging Kambin's triangle to allow safe insertion of the cage. A cannula is inserted into the disk to avoid damaging the exiting nerve. The disk material is shaved and curetted. Finally, the harvested bone is packed in a cage and inserted into the disk space. We analyze the complications, visual analog scores (VAS), and MacNab's criteria. One patient had an irritation in the exiting nerve at L4-L5. The VAS for back pain and leg pain decreased from 69 to 9 and from 60 to 9, respectively. The clinical outcome was considered excellent in eight and good in two patients. Kambin's triangle lies immediately behind the psoas major. Therefore, we consider KLIF as a lateral LIF procedure comparable with oblique or extreme LIF. However, unlike oblique or extreme LIF, there are no major vessels and organs in the surgical field; therefore, KLIF is the safest type of lateral LIF. Furthermore, using the endoscope, we can perform decompression directly using the facetectomy technique.

Myofibroblasts are increased in the dorsal layer of the hypertrophic ligamentum flavum in lumbar spinal canal stenosis

BACKGROUND CONTEXTHypertrophy of the ligamentum flavum (LF) is a major contributor to the development of lumbar spinal canal stenosis (LSS). Although previous studies have identified some factors related to hypertrophy of the LF, the etiology remains unclear. It is well known that myofibroblasts have a key role in the pathology of fibrosis in other tissues, including the skin, liver, kidney, and lung. We hypothesized that myofibroblasts were also important players in the pathology of fibrosis in the LF. PURPOSETo elucidate the distribution and role of myofibroblasts in the hypertrophic LF. STUDY DESIGNA histological, immunohistochemical, and gene expression analysis of the LF in the human lumbar spine. PATIENT SAMPLEHypertrophic LF tissue samples were collected from patients with LSS. OUTCOME MEASURESHistology, immunohistochemistry, microarray, reverse transcription-quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay. METHODSThe degree of fibrosis in the dural and dorsal layers of the LF was evaluated by Masson's trichrome tissue staining. Collagen gene expression was evaluated by quantitative reverse transcription polymerase chain reaction. Immunostaining of αSMA was performed to evaluate localization of myofibroblasts in LF tissue. The association between gene expression of alpha-smooth muscle actin (αSMA) and that of several types of collagen was investigated. The signal activated on the dorsal side of LF was examined by gene set enrichment analysis using microarray data. Expression levels of αSMA and several types of collagen in LF fibroblasts were investigated under hypoxic conditions. RESULTSIn the histological study using Masson's trichrome staining, the fibrosis score was significantly higher in the dorsal layer than in the dural layer. Gene expression levels for several types of collagen (COL1A1, COL1A2, COL3A1, COL5A1, COL6A1, and COL11A1) and heat shock protein 47 (a collagen-specific chaperone) were significantly higher in the dorsal layer. Furthermore, immunohistochemistry revealed a significantly greater number of αSMA-stained cells in the dorsal layer. There was a strong correlation of αSMA mRNA expression with COL1A-1 in LF fibroblasts. Gene set enrichment analysis showed that the set of fibrosis-related gene signals, including those for epithelial-mesenchymal transition, hypoxia, and inflammation, were significantly upregulated in the dorsal layer compared with the dural layer. Under hypoxic stimulation, expression of αSMA and several types of collagen was increased in LF fibroblasts. CONCLUSIONSThis study is the first to reveal that myofibroblast expression levels are higher in the dorsal layer of the LF than in the dural layer. We confirmed that hypertrophy of the LF in LSS is associated with increased expression of myofibroblasts in the dorsal layer. Hypoxia could be a cause of expression of myofibroblasts leading to fibrosis and finally to hypertrophy of the LF. CLINICAL SIGNIFICANCEThe results of this study partially elucidate the molecular mechanisms of LF hypertrophy and suggest that myofibroblasts may be involved in age-related degeneration of the LF.

Association between mild cognitive impairment and lumbar degenerative disease in a Japanese community: A cross-sectional study.

Lumbar degenerative disease and dementia are increasing in super-aging societies and are both related to physical dysfunction and pain. However, the relationship between these diseases remains unclear. This cross-sectional study aimed to investigate the comorbidity rates of lumbar spinal canal stenosis (LSS) and mild cognitive impairment (MCI) and clarify the association between LSS presence, lumbar symptoms, and quality of life (QOL) related to low back pain and cognitive impairment in the Japanese population. We enrolled 336 participants (men 124; women 212; mean age 72.2 years) from a medical checkup program. LSS was diagnosed using a self-administered questionnaire, and lumbar symptoms were evaluated using the visual analog scale (low back pain, and pain and numbness of the lower limb). QOL related to low back pain was evaluated using the Japanese Orthopedic Association Back-Pain Evaluation Questionnaire (JOABPEQ: pain, and lumbar, and gait function). Radiological lumbar degeneration was classified using Kellgren-Lawrence grading and lateral radiographs of the lumbar spine. Cognitive function was measured using the Mini Mental State Examination (MMSE), and MCI was defined by a summary score of MMSE ≤27. Logistic and multiple linear regression analyses were performed to analyze the association between MCI, summary score of MMSE, and lumbar degenerative disease. The comorbidity rate of MCI and LSS was 2.1%, and the rate of MCI was 41% in participants with LSS. Lumbar function in JOABPEQ was associated with MCI. The presence of LSS and lumbar function in JOABPEQ were associated with MMSE. Over one-third of the people with LSS had MCI. The presence of LSS and deterioration of QOL due to low back pain were related to cognitive impairment. We recommend evaluating cognitive function for patients with LSS because the rate of MCI was high in LSS participants.

Trans-Sacral Epiduroscopic Ho:YAG Laser Ablation of the Ligamentum Flavum in a Live Pig.

Introduction For the aging population, surgery for lumbar spinal canal stenosis (LSCS) requires minimally invasive procedures. Recently, trans-sacral epiduroscopic laser decompression for lumbar disc herniation has been reported with good results. In this study, we devised a new method to perform trans-sacral epiduroscopic laser ablation of the ligamentum flavum (LF), known to be the major cause of LSCS. Using a live pig, this study aims to evaluate the efficacy, safety, and drawbacks of this procedure. Methods Using an epiduroscope, we observed intra-spinal canal structures and then examined the feasibility and problems of a decompression procedure to ablate the LF using holmium:YAG (Ho:YAG) laser. The pig was observed for behavioral changes and neurological deficits after the procedure. Histological analysis was performed to evaluate the amount of tissue ablation and damage to surrounding tissues. Results Although it was possible to partially ablate the LF using the Ho:YAG laser under epiduroscopy, it was difficult to maintain a clear field of view, and freely decompressing the target lesion has been a challenge. After the first two experiments, the pig neither showed abnormal behavior nor any signs of pain or paresis. However, in the third experiment, the pig died during the operation. On autopsy, no thermal or mechanical injury was noted around the ablated site, including the dura mater and nerve root. Histological analysis showed that the LF and lamina were deeply ablated as the laser power increased, and no damage was noted on surrounding tissues beyond a depth of 500 μm. Conclusions Although Ho:YAG laser could ablate the ligamentum and bone tissues without causing damage to surrounding tissues, it was difficult to completely decompress the LF under epiduroscopy. This method is a potentially highly invasive procedure that requires caution in its clinical application and needs further improvement in terms of the instruments and techniques used.

Early results of full-endoscopic decompression of lumbar central canal stenosis by outside-in technique: A clinical and radiographic study.

Retrospective cohort study.Full-endoscopic decompression of lumbar spinal canal stenosis is being performed by endoscopic surgeons as an alternative to micro-lumbar decompression in the recent years. The outcomes of the procedure are reported by few authors only. The aim of this paper is to report the clinical and radiographic outcomes of full endoscopic lumbar decompression of central canal stenosis by outside-in technique at 1-year follow-up.We reviewed patients operated for lumbar central canal stenosis by full endoscopic decompression from May 2018 to November 2018. We analyzed the visual analogue scale scores for back and leg pain and Oswestry disability index at pre-op, post-op, and 1-year follow-up. At the same periods, we also evaluated disc height, segmental lordosis, whole lumbar lordosis on standing X-rays and canal cross sectional area at the affected level and at the adjacent levels on magnetic resonance imaging and the facet length and facet cross-sectional area on computed tomography scans. The degree of stenosis was judged by Schizas grading and the outcome at final follow-up was evaluated by MacNab criteria.We analyzed 32 patients with 43 levels (M:F = 14:18) with an average age of 63 (±11) years. The visual analogue scale back and leg improved from 5.4 (±1.3) and 7.8 (±2.3) to 1.6 (±0.5) and 1.4 (±1.2), respectively, and Oswestry disability index improved from 58.9 (±11.2) to 28 (±5.4) at 1-year follow-up. The average operative time per level was 50 (±16.2) minutes. The canal cross sectional area, on magnetic resonance imaging, improved from 85.78 mm2 (±28.45) to 150.5 mm2 (±38.66). The lumbar lordosis and segmental lordosis also improved significantly. The disc height was maintained in the postoperative period. All the radiographic improvements were maintained at 1-year follow-up. The MacNab criteria was excellent in 18 (56%), good in 11 (34%), and fair in 3 (9%) patients. None of the patients required conversion to open surgery or a revision surgery at follow-up. There was 1 patient with dural tear that was sealed with fibrin sealant patch endoscopically. There were 10 patients who had grade I stable listhesis preoperatively that did not progress at follow-up. No other complications like infection, hematoma formations etc. were observed in any patient.Full endoscopic outside-in decompression method is a safe and effective option for lumbar central canal stenosis with advantages of minimal invasive technique.

Prospective study on the treatment of degenerative lumbar spinal canal stenosis: Surgical versus conservative intervention

Background: The treatment decision of patients with moderately severe cases of degenerative lumbar spinal canal stenosis (LSS) whether conservative or surgical is highly dependable on physician evaluation without clear standards. The purpose of this study is to evaluate the effectiveness of conservative treatment of patients complaining of moderately severe degenerative LSS in comparison with surgical intervention throughout one year follow up. The present study was conducted on 60 patients with LSS: 30 patients treated with rehabilitation program and 30 patients treated with decompression surgery. All patients were assessed for pain and physical function before treatment, 3 months, 6 months and 12 months after treatment. Results: Both groups showed significant improvement of Oswestry Disability Index (ODI), ODI walk, and Zurich Claudication Questionnaire (ZCQ) symptoms and function subscales at 3, 6 and 12 months after treatment compared to baseline. However, at 1 year, the most patients of the conservative group did not maintain improvement in ODI and ZCQ subscales scores. The beneficial effect of operative treatment sustained throughout the 1-year follow-up. No serious complications were encountered in conservative group but, there were two patients in surgical group had serious complications. Conclusion: The conservative treatment yielded statistical significant improvement among patients with moderately severe LSS for three, six and twelve months follow up compared to baseline. Nonetheless, at all follow-up end points, the surgical group outperformed the conservative group statistically.

ELECTRODIAGNOSTIC PARAMETERS OF TIBIAL & SURAL NERVE IN LUMBAR SPINAL CANAL STENOSIS.

Background: Lumbar spinal canal stenosis (LSCS) is dened as the narrowing of the lumbar spinal canal due to bulging intervertebral discs and/or hypertrophy of the ligamentum avum and facet joints that results in the compression of nerve root that might affect the nerve conduction studies. Objective: To determine the electrodiagnostic parameters of tibial and sural nerve with and severity of lumbar spinal canal stenosis. Methods: A comparative study was conducted on 51 patients of LSCS diagnosed clinically and canal diameter measured on MRI. All patients were subjected to nerve conduction study by EMG Octopus manufactured by Clarity Medical Pvt. Ltd. Results: The mean age of participants was 49.0±16.77 years ( 22-85 years), out of which 26 (50.98%) were males and 25 (49.02%) were females. They were divided into 3 groups based on antero-posterior lumbar canal diameter for severity of stenosis. LSCS was found at multiple levels in spinal cord with most common site is LSCS in L4-L5. There was a signicant decrease in motor nerve conduction (p=0.01(Rt. & Lt. tibial)) and sensory nerve conduction (p= 0.007(Rt. sural), 0.008 (Lt. sural)) velocities. However, signicant differences in motor and sensory latencies and amplitude were not observed. Conclusion: The signicantly reduced motor and sensory nerve conduction velocities are suggestive of functional impairement of the tibial and sural nerve with the severity of LSC; however, the non signicant changes in latencies and amplitude suggests no evidence of peripheral demyelination or axonal loss.

P134. Midterm clinical and radiological outcomes of lumbar spinal stenosis with concurrent scoliosis and/or spondylolisthesis after minimally invasive lumbar decompression surgery: Minimum 5-year follow-up

<h3>BACKGROUND CONTEXT</h3> Several studies recently have been published about the sagittal spinal alignment of lumbar spinal canal stenosis (LSS) after decompression surgery, however, little is known about these variables of LSS with concurrent degenerative spondylolisthesis (DS) and/or lumbar scoliosis (DLS). With aging of the population, spine surgeons are currently more and more confronted with a wide variety of degenerative changes of the lumbar spine. <h3>PURPOSE</h3> The purpose of this study was to investigate whether the radiological and clinical outcomes differ depend on the concomitance after minimally invasive lumbar decompression surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective analysis of prospectively collected data. <h3>PATIENT SAMPLE</h3> A total of 244 patients underwent bilateral decompression via unilateral approach using microscope or microendscope at our instituted between 2008 and 2013, and were followed up for more than 5 years postoperatively. A total of 169 patients were included in the final analysis (88 women, 81 men; mean age at surgery, 69.5±9.2years). The patients were divided into three groups: LSS group (without DS and DLS; n=91), DS group (n=59) and DLS group (n=19) <h3>OUTCOME MEASURES</h3> Clinical outcomes were evaluated with the Japanese Orthopaedic Association (JOA) scoring system (29 possible points) and visual analog scale (VAS) score for low back pain (LBP), leg pain, leg numbness and achievement of minimal clinically important difference (MCID) of VAS for low back pain (LBP) or leg pain (LP). Furthermore all spinopelvic parameters such as 1) cervical lordosis (CL): C2–7 angle (positive means lordosis); 2) cervicothoracic kyphosis (CTK): C7–T5 angle (positive means kyphosis); 3) thoracic kyphosis (TK): T5–12 angle (positive means kyphosis); 4) lumbar lordosis: T12–S1 angle (positive means lordosis); 5) C7–S1 sagittal vertical axis (SVA): distance between C-7 plumb line and posterosuperior sacrum; 6) pelvic parameters: sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI) and PI – LL were evaluated. <h3>METHODS</h3> All patients underwent bilateral decompression via a unilateral approach to decompress the central and bilateral lateral recess using a microscope or the METRx Microendoscopic Discectomy System (Medtronic Sofamor Danek, Warsaw, IN, USA). Outcomes were quantified comparatively among Simple LSS group vs DS group (with anterior slip of more than 3mm) and DLS group (with ≥ 20° coronal Cobb angle) using low back pain (LBP) /leg pain/leg numbness visual analog scale (VAS) scores, the JOA scores and variables about sagittal plane alignment before surgery, 2 years and 5 years of follow-up. <h3>RESULTS</h3> In patients coexisting DS, the clinical outcomes at 2year and 5-year after surgery were similar with that of LSS except for VAS leg numbness. In patients coexisting DLS, the VAS leg pain at 2-year after surgery was significantly higher (34.5 vs 14.5, P=0.001) and the achievement rate of the minimal clinically important difference in VAS LBP and leg pain was significantly lower than LSS group (26.3% vs 52.7%; P=0.036, 42.1% vs 72.5%; P=0.01). The reoperation rate of DS group was significantly lower than that of LSS group (3.4% vs16.5%; P=0.01), but the DLS group was comparable to the LSS group (15.8% vs 16.5%; P=0.941). Lumbar lordosis (LL), pelvic tilt and pelvic incidence-LL were significantly improved and maintained for 5 years after surgery, however, sagittal vertical axis improved at 2-year follow-up, but no significantly difference was observed at 5-year follow-up in both the DS and the DLS group. <h3>CONCLUSIONS</h3> Among patients with DS and DLS, the clinical effectiveness and radiological changes after minimally lumbar decompression surgery alone was noninferior to that of LSS without deformity. The less invasive procedure should be considered for most LSS patients. <h3>FDA DEVICE/DRUG STATUS</h3> Unavailable from authors at time of publication.

Minimally invasive anteroposterior combined surgery using lateral lumbar interbody fusion without corpectomy for treatment of lumbar spinal canal stenosis associated with osteoporotic vertebral collapse.

Various reconstructive surgical procedures have been described for lumbar spinal canal stenosis (LSCS) with osteoporotic vertebral collapse (OVC); however, the optimal surgery remains controversial. In this study, the authors aimed to report the clinical and radiographic outcomes of their novel, less invasive, short-segment anteroposterior combined surgery (APCS) that utilized oblique lateral interbody fusion (OLIF) and posterior fusion without corpectomy to achieve decompression and reconstruction of anterior support in patients with LSCS-OVC. In this retrospective study, 20 patients with LSCS-OVC (mean age 79.6 years) underwent APCS and received follow-up for a mean of 38.6 months. All patients were unable to walk without support owing to severe low-back and leg pain. Cleft formations in the fractured vertebrae were identified on CT. APCS was performed on the basis of a novel classification of OVC into three types. In type A fractures with a collapsed rostral endplate, combined monosegment OLIF and posterior spinal fusion (PSF) were performed between the collapsed and rostral adjacent vertebrae. In type B fractures with a collapsed caudal endplate, combined monosegment OLIF and PSF were performed between the collapsed and caudal adjacent vertebrae. In type C fractures with severe collapse of both the rostral and caudal endplates, bisegment OLIF and PSF were performed between the rostral and caudal adjacent vertebrae, and pedicle screws were also inserted into the collapsed vertebra. Preoperative and postoperative clinical and radiographical status were reviewed. The mean number of fusion segments was 1.6. Walking ability improved in all patients, and the mean Japanese Orthopaedic Association score for recovery rate was 65.7%. At 1 year postoperatively, the mean preoperative Oswestry Disability Index of 65.6% had significantly improved to 21.1%. The mean local lordotic angle, which was -5.9° preoperatively, was corrected to 10.5° with surgery and was maintained at 7.7° at the final follow-up. The mean corrective angle was 16.4°, and the mean correction loss was 2.8°. The authors have proposed using minimally invasive, short-segment APCS with OLIF, tailored to the morphology of the collapsed vertebra, to treat LSCS-OVC. APCS achieves neural decompression, reconstruction of anterior support, and correction of local alignment.

Surgery Can Improve Locomotive Syndrome Due to Lumbar Spinal Canal Stenosis and Loco-Check Can Predict Best Timing of Surgery to Avoid Progress of Locomotive Syndrome.

Introduction The loco-check is a simple tool for evaluating locomotive syndrome (LS), and a previous report suggested that it can be used to identify patients with stage 2 LS. The purpose of this study was to investigate the improvement in LS stage after surgery based on the loco-check in elderly patients with lumbar spinal stenosis (LSS) and to clarify the characteristics associated with improvement to non-stage 2 LS. Methods We reviewed 40 elderly patients with LSS who underwent surgery at our institution. We compared the pre- and postoperative Japanese Orthopaedic Association score, loco-check, Oswestry Disability Index, EuroQoL-5 dimension utility values, and the EuroQoL-visual analog scale. We divided patients according to the presence or absence of stage 2 LS after surgery and compared their preoperative clinical findings and assessment measures. Results Ninety percent of all patients had been preoperatively diagnosed with stage 2 LS according to the loco-check. After surgery, patients showed a decreased number of affirmative answers on the loco-check, according to which only 65% were postoperatively diagnosed with stage 2 LS. The receiver operating characteristic curve analysis identified less than four affirmative answers on the loco-check before LSS as predictive of improvement to non-stage 2 LS. Conclusions Surgical treatment for elderly patients with LSS could improve LS. In patients with less than four affirmative answers on the loco-check preoperatively, improvement to non-stage 2 LS status may be possible.

WISP-1 induced by mechanical stress contributes to fibrosis and hypertrophy of the ligamentum flavum through Hedgehog-Gli1 signaling

Ongoing chronic fibrosis and hypertrophy of the ligamentum flavum (LF) is an important cause of lumbar spinal canal stenosis (LSCS). Our previous work showed that WNT1-inducible signaling pathway protein 1 (WISP-1) is a critical driver of LF fibrosis. However, the potential mechanism has not been explored. Here, we found that Gli1 was upregulated in hypertrophic LF tissues and required for fibrogenesis in fibroblasts. Moreover, mechanical stretching increased the expression of WISP-1 in LF fibroblasts. Furthermore, WISP-1 induced fibrogenesis in vitro through the Hedgehog-Gli1 pathway. This conclusion was supported by the fact that WISP-1 activated the Hedgehog-Gli1 pathway in LF fibroblasts and that cyclopamine attenuated the effect of WISP-1-induced fibrogenesis. WISP-1 also promoted the transition of fibroblasts into myofibroblasts via the Hedgehog pathway. Importantly, a hypertrophic LF rabbit model induced by mechanical stress also showed pathological changes in fibrosis and elevated expression of WISP-1, Gli1, and α-SMA. Therapeutic administration of cyclopamine reduced collagen expression, fibroblast proliferation, and myofibroblast differentiation and ameliorated fibrosis in the mechanical stress-induced rabbit model. Collectively, our findings show mechanical stress/WISP-1/Hedgehog signaling as a new fibrotic axis contributing to LF hypertrophy and identify Hedgehog signaling as a therapeutic target for the prevention and treatment of LF fibrosis.

Responsiveness and Minimal Clinically Important Difference of the 6-minute Walk Distance in Patients Undergoing Lumbar Spinal Canal Stenosis Surgery.

This was a retrospective review of prospectively collected data. We aimed to evaluate the responsiveness of the 6-minute walk distance (6MWD) and determine the threshold of the minimal clinically important difference (MCID) in the 6MWD in patients who underwent surgery for lumbar spinal canal stenosis (LSS) surgery. The 6MWD rapidly and objectively assesses the walking distance in patients with LSS. To date, no study has assessed the MCID in the 6MWD in patients who underwent LSS surgery. A total of 41 patients (16 women; average age: 69.4 y, SD: 7.8 y) were included and assessed preoperatively and at 6 months postoperatively. We evaluated the 6MWD and Oswestry Disability Index (ODI), which is a health-related patientrReported outcome, used as an anchor to calculate the MCID for in the 6MWD. We used 2 different approaches to examine the responsiveness of the 6MWD: internal and external responsiveness. The external responsiveness was assessed in 2 ways: one based on the anchoring questionnaire and the other based on the scale distribution of the scale. The anchor-based approach was evaluated using the Spearman rank correlation coefficient and the receiver operating characteristic curve. The distribution-based approach was evaluated using the minimal detectable change. The ODI scores and 6MWD for each anchor significantly improved postoperatively. The correlation coefficient between changes in the 6MWD and ODI was r=-0.58. The area under the receiver operating characteristic curve for the ODI anchor was 0.70 (95% confidence interval: 0.52-0.89), and the cutoff value for the ODI anchor was 50 m (sensitivity=0.57, specificity=0.71). In the distribution-based approach, the minimal detectable change for the 6MWD was 105.9 m. Both the internal and the external responsiveness of the 6MWD were validated using the ODI. Therefore, the MCID in the 6MWD in patients undergoing LSS surgery ranges from 50 to 105.9 m. Level III.

Relationship Between Vertebral Bone Marrow Edema and Early Progression of Intervertebral Disc Wedge or Narrowing After Lumbar Decompression Surgery.

A retrospective study. The aim of this study was to review clinical and imaging features in patients with lumbar spinal canal stenosis (LSS) with and without postoperative early progression of intervertebral disc degeneration (IDD) and to identify predictive factors. Progression of IDD after lumbar decompression surgery can induce low back pain and leg pain, and may require revision surgery. However, risk factors for postoperative radiological changes indicating IDD linked to development of symptoms have not been described. We included 564 patients with LSS without degenerative lumbar scoliosis who underwent lumbar decompression surgery without fusion. Clinical features and imaging findings were compared in cases with (group P) and without (group N) progression of IDD (intervertebral disc wedge or narrowing) at 1 year after surgery. Of the 564 patients, 49 (8.7%) were in group P. On preoperative MRI, all patients in group P had findings of vertebral bone marrow edema (diffuse high intensity on T2-weighted images and low-intensity on T1-weighted images), compared to only 5.4% in group N. The rate of revision surgery was significantly higher in group P in 5 years' follow-up (12.2% vs. 1.4%, P < 0.01). In group P, 44.9% of patients developed postoperative symptoms associated with postoperative radiological changes, and the frequency was higher in narrowing-type than in wedge-type cases. Vertebral bone marrow edema area and IDD grade were not predictors for postoperative early IDD progression. Careful consideration is required to determine whether lumbar decompression surgery should be performed if vertebral bone marrow edema is detected on MRI, since this is a predictor for a negative clinical outcome. If surgery is symptomati-cally urgent, careful clinical and radiological follow-up is required.Level of Evidence: 4.

Role of redundant nerve roots in clinical manifestations of lumbar spine stenosis.

Background: Redundant nerve roots (RNRs) are defined as elongated, thickened, and tortious appearing roots of the cauda equina secondary to lumbar spinal canal stenosis (LSCS). The study compared the clinical and radiological features of patients with LSCS with versus without RNR.Methods: This retrospective study was performed on 55 patients who underwent decompressive surgery for degenerative LSCS. Patients were divided into two groups based on the presence of RNR in their preoperative magnetic resonance imaging, as evaluated by a radiologist blinded to the study design. Medical records were reviewed for basic demographic, clinical MR presentation, and outcomes utilizing Japanese Orthopaedic Association (JOA) scores.Results: The mean age of enrolled patients was 57.1, with mean follow-up of 4.0 months. RNR was found in 22 (40%) of patients with LSCS. These patients were older than those patients without RNR (62.2 vs. 53.7). Interestingly, there were no statistically significant differences in clinical presentations, duration of symptoms, and outcomes using JOA scores between the two groups.Conclusion: RNR is a relatively common radiological finding (i.e., 40%) in patients with LSCS. It is more likely to be observed in older patients. However, no significant differences were noted in clinical presentation and functional outcomes with respect to the presence or absence of RNR.

The impact of sagittal imbalance on walking in patients with lumbar spinal canal stenosis.

Gait and posture disorder severely impedes the quality of life of affected patients with lumbar spinal canal stenosis (LSCS). Despite the major health concern, there is a paucity of literature about the relationships among spatiotemporal gait parameters and spinal sagittal parameters. This is a cross sectional study performed in a single tertiary referral center to determine the relationships among spatiotemporal gait parameters and spinal sagittal parameters in patients with LSCS. A total of 164 consecutive patients with LSCS, 87 men and 77 women with mean age of 70.7 years, were enrolled. Spatiotemporal gait parameters were studied using a gait analysis system. Spinal sagittal parameters were studied including sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic inclination (PI), and pelvic tilt (PT) both in the neutral and stepped positions. SVA was significantly larger in the stepped position than in the neutral position (neutral position, 72.5 mm; stepped position, 96.8 mm; p = 0.003). Parameters regarding the pelvis exhibited significant differences, which could represent pelvic anteversion in the stepped position. By stepwise multiple regression analysis, the prediction models, containing SVA (neutral) and PT (stepped) for double supporting phase, exhibited statistical significance, and accounted for approximately 50% of the variance. The present study provides statistically established evidence of correlation among spatiotemporal gait parameters and spinal sagittal parameters. Differences between sagittal parameters in neutral and stepped position may stand for the postural control during gait cycle, and increased SVA in neutral position and increased PT in stepped position may correlate with prolonged double supporting phase.