Background and purpose
MRI is the modality of choice when diagnosing spinal stenosis but it also shows that stenosis is prevalent in asymptomatic subjects over 60. The relationship between preoperative health-related quality of life, functional status, leg and back pain, and the objectively measured dural sac area in single and multilevel stenosis is unknown. We assessed this relationship in a prospective study.
Patients and methods
The cohort included 109 consecutive patients with central spinal stenosis operated on with decompressive laminectomy or laminotomy. Preoperatively, all patients completed the questionnaires for EQ-5D, SF-36, Oswestry disability index (ODI), estimated walking distance and leg and back pain (VAS). The cross-sectional area of the dural sac was measured at relevant disc levels in mm2, and spondylolisthesis was measured in mm. For comparison, the area of the most narrow level, the number of levels with dural sac area < 70 mm2, and spondylolisthesis were studied.
Before surgery, patients with central spinal stenosis had low HRLQoL and functional status, and high pain levels. Patients with multilevel stenosis had better general health (p = 0.04) and less leg and back pain despite having smaller dural sac area than patients with single-level stenosis. There was a poor correlation between walking distance, ODI, the SF-36, EQ-5D, and leg and back pain levels on the one hand and dural sac area on the other. Women more often had multilevel spinal stenosis (p = 0.05) and spondylolisthesis (p < 0.001). Spondylolisthetic patients more often had small dural sac area (p = 0.04) and multilevel stenosis (p = 0.06).
Our findings indicate that HRQoL, function, and pain measured preoperatively correlate with morphological changes on MRI to a limited extent.
Grading stenosis based on morphology of the dural sac on MRI rather than surface measurements deﬁnes stenosis in various topics. To study the relations between the grading stenosis and the severity of clinical symptoms of spinal stenosis in patients diagnosed with lumbar spinal canal stenosis (LSCS).
Patients diagnosed with lumbar spinal stenosis who were candidate for surgery entered into this cross sectional study. Grading stenosis based on morphology of the dural sac on magnetic resonance imaging (MRI) was determined. The severity of symptoms was evaluated based on the duration of symptoms, walking distance, visual analogue scale (VAS) of leg pain/numbness, the Neurogenic Claudication Outcome Score (NCOS) and the Japanese Orthopaedic Association (JOA) Score. We studied distribution of grades, relation between morphologic grading and severity of symptoms. The severity of symptoms and morphologic grading were compared between patients with different grades stenosis.
Eighty four patients were eligible to enter the study during the two years course of study. Patients were aged 61.2 ± 11.3 (18 to 82 years). All of patients were grades C and D stenosis 56 and 28 respectively. The symptoms were significantly worse in patients with a morphologic grade D stenosis (p less than 0.001). The walking distance in the patients with grade D stenosis was significantly shorter than those with grade C stenosis (P less than 0.001). In addition, the VAS of leg numbness in patients with grade D stenosis was significantly higher than those with a morphologic grade C stenosis (P less than 0.001). The JOA and the NCOS scores were significantly lower in patients with grade D stenosis (P less than 0.001). No significant difference was observed in the characteristics, duration of symptoms or VAS of leg pain between the groups.
The findings suggest that the effect of grade D stenosis on patients’ symptoms, walking ability and functionality are more profound than grade C stenosis.
Lumbar spinal canal stenosis, Grading stenosis relationship, Severity of clinical symptoms
Decompression for lumbar spinal stenosis is one of the most frequent operations on the spine today. The most common complication seems to be a peroperative dural lesion. There are few prospective studies on this complication regarding incidence and effect on long-term outcome; this is the background for the current study.
Materials and methods
Swespine, the Swedish Spine Register documents the majority (>80%) of lumbar spine operations in Sweden today. Within the framework of this register, totally 3,699 operations for spinal stenosis during a 5-year period were studied regarding complications and 1-year postoperative outcome. Mean patient age was 66 (37–92) years and 44% were males. Fourteen percent were smokers and 19% had undergone previous lumbar spine surgery.
The overall incidence of a peroperative dural lesion was 7.4%, 8.5% of patients undergoing decompressive surgery only and 5.5% of patients undergoing decompressive surgery + fusion (p < 0.001). A logistic regression analysis demonstrated that (high) age (p < 0.0004), previous surgery (p < 0.036) and smoking (p < 0.049) were significantly predictive factors for dural lesions. An odds ratio estimate demonstrated an age-related risk increase with 2.7% per year. The risk for dural lesions also increased with number of levels decompressed. The 1-year outcome was identical in the two groups with and without a dural lesion.
A dural lesion was seen in 7.4% of decompressive operations for spinal stenosis. High age, previous surgery and smoking were risk factors for sustaining a lesion, which, however, did not affect the 1-year outcome negatively.
Spinal stenosis; Complication; Surgery; Outcome
Symptomatic degenerative central lumbar spinal stenosis (LSS) is a frequent indication for decompressive spinal surgery, to reduce spinal claudication. No data are as yet available on the effect of surgery on the level of activity measured with objective long-term monitoring. The aim of this prospective, controlled study was to objectively quantify the level of activity in central LSS patients before and after surgery, using a continuous measurement device. The objective data were correlated with subjective clinical results and the radiographic degree of stenosis. Forty-seven patients with central LSS and typical spinal claudication scheduled for surgery were included. The level of activity (number of gait cycles) was quantified for 7 consecutive days using the StepWatch Activity Monitor (SAM). Visual analogue scales (VAS) for back and leg pain, Oswestry disability index and Roland–Morris score were used to assess the patients’ clinical status. The patients were investigated before surgery and 3 and 12 months after surgery. In addition, the radiographic extent of central LSS was measured digitally on preoperative magnetic resonance imaging or computed tomography. The following results were found preoperatively: 3,578 gait cycles/day, VAS for back pain 5.7 and for leg pain 6.5. Three months after surgery, the patients showed improvement: 4,145 gait cycles/day, VAS for back pain 4.0 and for leg pain 3.0. Twelve months after surgery, the improvement continued: 4,335 gait cycles/day, VAS for back pain 4.1 and for leg pain 3.3. The clinical results and SAM results showed significant improvement when preoperative data were compared with data 3 and 12 months after surgery. The results 12 months after surgery did not differ significantly from those 3 months after surgery. The level of activity correlated significantly with the degree of leg pain. The mean cross-sectional area of the spinal canal at the central LSS was 94 mm2. The radiographic results did not correlate either with objective SAM results or with clinical outcome parameters. In conclusion, this study is the first to present objective data on continuous activity monitoring/measurements in patients with central LSS. The SAM could be an adequate tool for performing these measurements in spine patients. Except for leg pain, the objective SAM results did not correlate with the clinical results or with the radiographic extent of central LSS.
Step activity monitor (SAM); Lumbar spinal stenosis; Decompression; Level of activity; Mobility
The ability of bone morphogenetic proteins (BMPs) to induce bone formation has led to a multitude of investigations into their use as bone graft substitutes in spinal surgery. The purpose of this multi-center clinical pilot study was to evaluate the safety and efficacy of BMP-7 (osteogenic protein 1, OP-1), in the form of a putty, combined with autograft for intertransverse process fusion of the lumbar spine in patients with symptomatic spinal stenosis and degenerative spondylolisthesis following spinal decompression. Twelve patients with spinal stenosis and degenerative lumbar spondylolisthesis underwent a laminectomy and partial or complete medial facetectomy as required for decompression of the neural elements, followed by an intertransverse process fusion by placing iliac crest autograft and OP-1 putty between the decorticated transverse processes. No instrumentation was used. Patients were followed clinically using the Oswestry scale and SF-36 outcome forms, and radiographically using static and dynamic radiographs to assess their fusion status over a 2-year period. Independent and blinded radiologists assessed the films for the presence of bridging bone between the transverse processes and measured translation and angulation on dynamic films using digital calipers. Radiographic outcome was compared to a historical control (autograft alone fusion without instrumentation for the treatment of degenerative spondylolisthesis). All adverse events were recorded prospectively. The results showed eight of the nine evaluable patients (89%) obtained at least a 20% improvement in their preoperative Oswestry score, while five of ten patients (50%) with radiographic follow-up achieved a solid fusion by the criteria used in this study. Bridging bone on the anteroposterior film was observed in seven of the ten patients (70%). No systemic toxicity, ectopic bone formation, recurrent stenosis or other adverse events related to the OP-1 putty implant were observed. A successful fusion was observed in slightly over half the patients in this study, using stringent criteria without adjunctive spinal instrumentation. This study did not demonstrate the statistical superiority of OP-1 combined with autograft over an autograft alone historical control, in which the fusion rate was 45%. There were no adverse events related to the OP-1 putty implant in this study, which supports findings in other studies suggesting the safety of bone morphogenetic proteins in spinal surgery.
Lumbar spine; Fusion; BMP; Spondylolisthesis; OP-1 putty
Because neither the degree of constriction of the spinal canal considered to be symptomatic for lumbar spinal stenosis nor the relationship between the clinical appearance and the degree of a radiologically verified constriction is clear, a correlation of patient’s disability level and radiographic constriction of the lumbar spinal canal is of interest. The aim of this study was to establish a relationship between the degree of radiologically established anatomical stenosis and the severity of self-assessed Oswestry Disability Index in patients undergoing surgery for degenerative lumbar spinal stenosis. Sixty-three consecutive patients with degenerative lumbar spinal stenosis who were scheduled for elective surgery were enrolled in the study. All patients underwent preoperative magnetic resonance imaging and completed a self-assessment Oswestry Disability Index questionnaire. Quantitative image evaluation for lumbar spinal stenosis included the dural sac cross-sectional area, and qualitative evaluation of the lateral recess and foraminal stenosis were also performed. Every patient subsequently answered the national translation of the Oswestry Disability Index questionnaire and the percentage disability was calculated. Statistical analysis of the data was performed to seek a relationship between radiological stenosis and percentage disability recorded by the Oswestry Disability Index. Upon radiological assessment, 27 of the 63 patients evaluated had severe and 33 patients had moderate central dural sac stenosis; 11 had grade 3 and 27 had grade 2 nerve root compromise in the lateral recess; 22 had grade 3 and 37 had grade 2 foraminal stenosis. On the basis of the percentage disability score, of the 63 patients, 10 patients demonstrated mild disability, 13 patients moderate disability, 25 patients severe disability, 12 patients were crippled and three patients were bedridden. Radiologically, eight patients with severe central stenosis and nine patients with moderate lateral stenosis demonstrated only minimal disability on percentage Oswestry Disability Index scores. Statistical evaluation of central and lateral radiological stenosis versus Oswestry Disability Index percentage scores showed no significant correlation. In conclusion, lumbar spinal stenosis remains a clinico-radiological syndrome, and both the clinical picture and the magnetic resonance imaging findings are important when evaluating and discussing surgery with patients having this diagnosis. MR imaging has to be used to determine the levels to be decompressed.
Spine, abnormalities; Spine, MR; Lumbar spinal stenosis; Oswestry Disability Index
The ability of bone morphogenetic proteins (BMPs) to induce bone formation has led to an increasing interest in the potential for their use in fusion surgery. The purpose of this multi-center clinical pilot study was to evaluate the safety of one such BMP—osteogenic protein 1, in the form of OP-1 putty—combined with autograft for intertransverse process fusion of the lumbar spine in patients with symptomatic spinal stenosis and degenerative spondylolisthesis following spinal decompression. Twelve patients with spinal stenosis and degenerative lumbar spondylolisthesis underwent laminectomy and partial or complete medial facetectomy as required for decompression of the neural elements followed by intertransverse process fusion by placing iliac crest autograft and OP-1 putty between the decorticated transverse processes. No instrumentation was used. Patients were followed clinically using the Oswestry scale and radiographically using static and dynamic radiographs to assess their fusion status. Independent and blinded radiologists assessed the films for the presence of bridging bone between the transverse processes and measured translation and angulation on dynamic films using digital calipers. In addition to bridging bone, less than or equal to 5° of angular motion and less than or equal to 2 mm of translation were required to classify the patients as successfully fused, as per the definition of successful fusion provided by the FDA for use in clinical trials involving investigational devices to attain spinal fusion. Radiographic outcome was compared to a historical control (autograft alone fusion without instrumentation for the treatment of degenerative spondylolisthesis). All adverse events were recorded prospectively. The results showed 9 of the 12 patients (75%) obtained at least a 20% improvement in their preoperative Oswestry score, while 6 of 11 patients (55%) with radiographic follow-up achieved a solid fusion by the criteria used in this study. Bridging bone on the anteroposterior film was observed in 10 of the 11 patients (91%). No systemic toxicity, ectopic bone formation, recurrent stenosis or other adverse events related to the OP-1 putty implant were observed. A successful fusion was observed in slightly over half the patients in this study, using stringent criteria without adjunctive spinal instrumentation. This study did not demonstrate the superiority of OP-1 combined with autograft over an autograft alone historical control, in which the fusion rate was approximately 45%. The lack of adverse events related to the OP-1 putty implant in this study is in agreement with other studies supporting the safety of bone morphogenetic proteins in spinal surgery.
Lumbar spine; Fusion; BMP; Spondylolisthesis; OP-1 putty
Lumbar spinal stenosis is a frequent indication for spinal surgery. The predictive quality of treadmill testing and MRI for diagnostic verification is not yet clearly defined. Aim of the current study was to assess correlations between treadmill testing and MRI findings in the lumbar spine. Twenty-five patients with lumbar spinal stenosis were prospectively examined. Treadmill tests were performed and the area of the dural sac and neuroforamina was examined with MRI for the narrowest spinal segment. VAS and ODI were used for clinical assessment. The median age of the patients was 67 years. In the narrowest spinal segment the median area of the dural sac was 91 mm2. The median ODI was 66 per cent. The median walking distance in the treadmill test was 70 m. The distance reached in the treadmill test correlated with the area of the dural sac (Spearman’s ρ = 0.53) and ODI (ρ = −0.51), but not with the area of the neuroforamina and VAS. The distance reached in the treadmill test predicts the grade of stenosis in MRI but has a limited diagnostic importance for the level of clinical symptoms in lumbar spinal stenosis.
Spinal stenosis; Treadmill test; MRI; Spine; Spinal canal
Interspinous distraction devices (IPDD) are indicated as stand-alone devices for the treatment of spinal stenosis. The purpose of this study is to evaluate the results of patients undergoing surgery for spinal stenosis with a combination of unilateral microdecompression and interspinous distraction device insertion.
This is a prospective clinical and radiological study of minimum 2 years follow-up. Twenty-two patients (average age 64.5 years) with low-back pain and unilateral sciatica underwent decompressive surgery for lumbar spinal stenosis. Visual Analogue Scale, Oswestry Disability Index and walking capacity plus radiologic measurements of posterior disc height of the involved level and lumbar lordosis Cobb angle were documented both preoperatively and postoperatively. One-sided posterior subarticular and foraminal decompression was conducted followed by dynamic stabilization of the diseased level with an IPDD (X-STOP).
The average follow-up time was 27.4 months. Visual Analogue Scale and Oswestry Disability Index improved statistically significantly (p < 0.001) in the last follow-up exam. Also, the walking distance increased in all patients but two. Posterior intervertebral disc height of the diseased level widened average 1.8 mm in the postoperative radiograph compared to the preoperative. No major complication, including implant failure or spinous process breakage, has been observed.
The described surgical technique using unilateral microdecompression and IPDD insertion is a clinically effective and radiologically viable treatment method for symptoms of spinal stenosis resistant to non-operative treatment.
IPDD; X-STOP; Microdecompression; Spinal stenosis
The effect of the duration of symptoms on the outcome of lumbar decompression surgery is not known. The aim of our study was to determine the predictors of functional outcome of lumbar decompression surgery for degenerative spinal stenosis with particular emphasis on the duration of symptoms. In this prospective cohort study, we recruited 100 patients with a full data set available at 1-year and 85% at 2-year follow-ups: 49 females and 51 males with an average age of 62 (range 52–82). The pre- and post-operative outcome measures were Oswestry disability index (ODI), low back outcome score (LBOS), pain visual analogue score (VAS), modified somatic perception (MSP) and modified Zung depression (MZD) score. Dural tear occurred in 14%, and there was one post-operative extra-dural heamatoma. Overall, the ODI improved from a pre-operative of 56 (±13) to a 1-year ODI of 40 (±22) and at 2-year ODI of 40 (±21). The VAS improved from an average of 8 to 5.2 at 1 year and 4.9 at 2 years. There was a statistical significant association between symptom duration and the change in ODI (P=0.007 at 1-year follow-up, P=0.001 at 2-year follow-up), LBOS (P=0.001 at 1-year follow-up, P<0.001 at 2-year follow-up) and VAS (P=0.003 at 1-year follow-up, P=0.001 at 2-year follow-up). Subgroup analyses showed that patients with symptom duration of less than 33 months had a more favourable result. In addition, the patients who rated the operation as excellent had a statistically significantly shorter duration of symptoms. We have not found a predictive value for age at operation, MSP or MZD. The number of levels of decompression and the different types of decompression surgery did not influence the surgical results. Our study indicates that the symptom duration of more than 33 months has a less favourable functional outcome.
Duration of symptoms; Predictors; Degenerative spinal stenosis; Lumbar decompression surgery; Functional outcome
The SPORT (Spine Patient Outcomes Research Trial) reported favorable surgery outcomes over 2 years among patients with stenosis with and without degenerative spondylolisthesis, but the economic value of these surgeries is uncertain.
To assess the short-term cost-effectiveness of spine surgery relative to nonoperative care for stenosis alone and for stenosis with spondylolisthesis.
Prospective cohort study.
Resource utilization, productivity, and EuroQol EQ-5D score measured at 6 weeks and at 3, 6, 12, and 24 months after treatment among SPORT participants.
Patients with image-confirmed spinal stenosis, with and without degenerative spondylolisthesis.
Nonoperative care or surgery (primarily decompressive laminectomy for stenosis and decompressive laminectomy with fusion for stenosis associated with degenerative spondylolisthesis).
Cost per quality-adjusted life-year (QALY) gained.
Results of Base-Case Analysis
Among 634 patients with stenosis, 394 (62%) had surgery, most often decompressive laminectomy (320 of 394 [81%]). Stenosis surgeries improved health to a greater extent than nonoperative care (QALY gain, 0.17 [95% CI, 0.12 to 0.22]) at a cost of $77 600 (CI, $49 600 to $120 000) per QALY gained. Among 601 patients with degenerative spondylolisthesis, 368 (61%) had surgery, most including fusion (344 of 368 [93%]) and most with instrumentation (269 of 344 [78%]). Degenerative spondylolisthesis surgeries significantly improved health versus non-operative care (QALY gain, 0.23 [CI, 0.19 to 0.27]), at a cost of $115 600 (CI, $90 800 to $144 900) per QALY gained.
Result of Sensitivity Analysis
Surgery cost markedly affected the value of surgery.
The study used self-reported utilization data, 2-year time horizon, and as-treated analysis to address treatment non-adherence among randomly assigned participants.
The economic value of spinal stenosis surgery at 2 years compares favorably with many health interventions. Degenerative spondylolisthesis surgery is not highly cost-effective over 2 years but could show value over a longer time horizon.
As-treated analysis of the Spine Patient Outcomes Research Trial (SPORT).
To compare baseline characteristics and surgical and nonoperative outcomes in degenerative spondylolisthesis (DS) and spinal stenosis (SpS) patients stratified by predominant pain location (i.e. leg vs. back).
Summary of Background Data
Evidence suggests that degenerative spondylolisthesis (DS) and spinal stenosis (SpS) patients with predominant leg pain may have better surgical outcomes than patients with predominant low back pain (LBP).
The DS cohort included 591 patients (62% underwent surgery), and the SpS cohort included 615 patients (62% underwent surgery). Patients were classified as leg pain predominant, LBP predominant or having equal pain according to baseline pain scores. Baseline characteristics were compared between the three predominant pain location groups within each diagnostic category, and changes in surgical and nonoperative outcome scores were compared through two years. Longitudinal regression models including baseline covariates were used to control for confounders.
Among DS patients at baseline, 34% had predominant leg pain, 26% had predominant LBP, and 40% had equal pain. Similarly, 32% of SpS patients had predominant leg pain, 26% had predominant LBP, and 42% had equal pain. DS and SpS patients with predominant leg pain had baseline scores indicative of less severe symptoms. Leg pain predominant DS and SpS patients treated surgically improved significantly more than LBP predominant patients on all primary outcome measures at one and two years. Surgical outcomes for the equal pain groups were intermediate to those of the predominant leg pain and LBP groups. The differences in nonoperative outcomes were less consistent.
Predominant leg pain patients improved significantly more with surgery than predominant LBP patients. However, predominant LBP patients still improved significantly more with surgery than with nonoperative treatment.
Degenerative Spondylolisthesis; Spinal Stenosis; SPORT; Leg Pain; Back Pain
Decompression surgery is an increasingly common operation for the treatment of lumbar spinal stenosis. Although good relief from leg pain is expected after surgery, long term results of pain relief and function are more uncertain. This study prospectively followed a cohort of patients presenting with the signs and symptoms of spinal stenosis, who underwent decompression surgery to ascertain the long term outcome with respect to pain and function using visual analogue pain scores, the Oswestry Disability Index, and the Short Form 36, a general health questionnaire. From an initial pool of 84 recruited patients, 7 withdrew from surgical intervention; of the remaining 77, 51 (66%) returned for follow up assessments at 5 years. In these responders, a significant improvement was observed in back and leg pain, which was sustained for at least 1 year (P < 0.01). A significant improvement was also seen in physical function (P < 0.05) as assessed by Oswestry and SF-36. Although an initial improvement was noted in social function, this was not observed at 5 years. This study has demonstrated that decompression surgery is successful in relieving symptoms of lumbar spinal stenosis. Physical function, back and leg pain are significantly improved after 5 years but initial significant improvements in social function diminish over time.
Lumbar spinal stenosis; Decompression surgery; Pain; Physical function; Social function
Surgery for spinal stenosis is widely performed, but its effectiveness as compared with nonsurgical treatment has not been shown in controlled trials.
Surgical candidates with a history of at least 12 weeks of symptoms and spinal stenosis without spondylolisthesis (as confirmed on imaging) were enrolled in either a randomized cohort or an observational cohort at 13 U.S. spine clinics. Treatment was decompressive surgery or usual nonsurgical care. The primary outcomes were measures of bodily pain and physical function on the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and the modified Oswestry Disability Index at 6 weeks, 3 months, 6 months, and 1 and 2 years.
A total of 289 patients were enrolled in the randomized cohort, and 365 patients were enrolled in the observational cohort. At 2 years, 67% of patients who were randomly assigned to surgery had undergone surgery, whereas 43% of those who were randomly assigned to receive nonsurgical care had also undergone surgery. Despite the high level of nonadherence, the intention-to-treat analysis of the randomized cohort showed a significant treatment effect favoring surgery on the SF-36 scale for bodily pain, with a mean difference in change from baseline of 7.8 (95% confidence interval, 1.5 to 14.1); however, there was no significant difference in scores on physical function or on the Oswestry Disability Index. The as-treated analysis, which combined both cohorts and was adjusted for potential confounders, showed a significant advantage for surgery by 3 months for all primary outcomes; these changes remained significant at 2 years.
In the combined as-treated analysis, patients who underwent surgery showed significantly more improvement in all primary outcomes than did patients who were treated nonsurgically. (ClinicalTrials.gov number, NCT00000411.)
Early postoperative MRI after spinal surgery is difficult to interpret because of confounding postoperative mass effects and frequent occurrence of epidural hematomas. Purpose of this prospective study is to evaluate prevalence, extent and significance of hematoma in the first postoperative week in asymptomatic patients after decompression for lumbar stenosis and to determine the degree of clinically significant dura compression by comparing with the patients with postoperative symptoms. MRI was performed in 30 asymptomatic patients (47 levels) in the first week after lumbar spine decompression for degenerative stenosis. Eleven patients requiring surgical revision (16 levels) for symptomatic early postoperative hematoma were used for comparison. In both groups the cross-sectional area of the maximum dural compression (bony stenosis and dural sac expansion) was measured preoperatively and postoperatively by an experienced radiologist. Epidural hematoma was seen in 42.5% in asymptomatic patients (20/47 levels). The median area of postoperative hematoma at the operated level was 176 mm2 in asymptomatic patients and 365 mm2 in symptomatic patients. The median cross-sectional area of the dural sac at the operated level was 128.5 and 0 mm2 in asymptomatic and symptomatic patients, respectively, at the site of maximal compression. In the symptomatic group 75% of the patients had a maximal postoperative dural sac area of 58.5 mm2 or less, whereas in the asymptomatic group 75% of patients with epidural hematoma had an area of 75 mm2 or more. The size of hematoma and the degree of dural sac compression were significantly larger in patients with symptoms needing surgical revision. Dural sac area of less than 75 mm2 in early postoperative MRI was found to be the threshold for clinical significance.
Epidural hematoma; Early postoperative MRI; Spinal stenosis; Neural compression
Previous research has shown an association between preoperative depressive symptoms and a poorer surgery outcome in lumbar spinal stenosis (LSS). It is not known whether depressive symptoms throughout the recovery period are relevant to the outcome of surgery in LSS. In this prospective clinical study the predictive value of preoperative and postoperative depressive symptoms with respect to the surgery outcome is reported.
96 patients (mean age 62 years) with symptomatic lumbar spinal stenosis underwent decompressive surgery. They completed the same set of questionnaires preoperatively and 3 months, 6 months, 1 year and 2 years postoperatively. Depressive symptoms were assessed with the 21-item Beck Depression Inventory. Physical functioning and pain were assessed with the Oswestry Disability Index, the Stucki Questionnaire, self-reported walking ability and VAS rating. Logistic regression analyses were used to examine the predictive value of preoperative and postoperative depressive symptoms regarding the surgery outcome. A "good" outcome was defined in two ways: first, by gaining a 30% improvement in relation to the preoperative disability and pain, and second, by having a score at or below the median value for disability and pain on 2-year follow-up.
Having elevated depressive symptoms particularly on 3-month follow-up was predictive of a poorer surgery outcome regarding pain and disability: when the outcome was defined as less than 30% improvement from the baseline, the OR's (with 95% confidence intervals) were 2.94 (1.06-8.12), <0.05 for Oswestry and 3.33 (1.13-9.79), <0.05 for VAS. In median split approach the OR was 4.11 (1.27-13.32), <0.05 for Oswestry. Predictive associations also emerged between having depressive symptoms on 6-month and 1-year follow-ups and a poorer outcome regarding disability. The predictive value of elevated depressive symptoms particularly with respect to 2-yeard disability was evident whether the outcome was defined as a 30% improvement compared to the preoperative status or as belonging to the better scoring half of the study population on 2-year follow-up.
Preoperative and postoperative depressive symptoms may indicate those patients at greater risk of a poorer postoperative functional ability. For these patients, further clinical evaluation should be carried out, especially during postoperative stages.
Lumbar spinal stenosis (LSS) treatment is based primarily on the clinical criteria providing that imaging confirms radiological stenosis. The radiological measurement more commonly used is the dural sac cross-sectional area (DSCA). It has been recently shown that grading stenosis based on the morphology of the dural sac as seen on axial T2 MRI images, better reflects severity of stenosis than DSCA and is of prognostic value. This radiological prospective study investigates the variability of surface measurements and morphological grading of stenosis for varying degrees of angulation of the T2 axial images relative to the disc space as observed in clinical practice.
Materials and methods
Lumbar spine TSE T2 three-dimensional (3D) MRI sequences were obtained from 32 consecutive patients presenting with either suspected spinal stenosis or low back pain. Axial reconstructions using the OsiriX software at 0°, 10°, 20° and 30° relative to the disc space orientation were obtained for a total of 97 levels. For each level, DSCA was digitally measured and stenosis was graded according to the 4-point (A–D) morphological grading by two observers.
A good interobserver agreement was found in grade evaluation of stenosis (k = 0.71). DSCA varied significantly as the slice orientation increased from 0° to +10°, +20° and +30° at each level examined (P < 0.0001) (−15 to +32% at 10°, −24 to +143% at 20° and −29 to +231% at 30° of slice orientation). Stenosis definition based on the surface measurements changed in 39 out of the 97 levels studied, whereas the morphology grade was modified only in two levels (P < 0.01).
The need to obtain continuous slices using the classical 2D MRI acquisition technique entails often at least a 10° slice inclination relative to one of the studied discs. Even at this low angulation, we found a significantly statistical difference between surface changes and morphological grading change. In clinical practice, given the above findings, it might therefore not be necessary to align the axial cuts to each individual disc level which could be more time-consuming than obtaining a single series of axial cuts perpendicular to the middle of the lumbar spine or to the most stenotic level. In conclusion, morphological grading seems to offer an alternative means of assessing severity of spinal stenosis that is little affected by image acquisition technique.
Lumbar spinal stenosis (LSS); Imaging; MRI; Lumbar spine; Diagnostic
Decompression surgery for lumbar spinal stenosis is a common procedure. After surgery, segmental instability sometimes occurs, therefore, different methods for restabilization have been developed. Dynamic stabilization systems have been designed to improve segmental stability. In this study, clinical results of patients with lumbar spinal stenosis that underwent decompression and stabilization with the Accuflex dynamic system are presented; clinical, radiographic, and magnetic resonance imaging (MRI) findings are fully described. Improvements in all clinical measurements, including visual analog scale for back and leg pain, Oswestry disability index, and SF-36 health status survey were noticed. At a 2-year follow-up, 22.22% of patients required hardware removal due to fatigue while in 83% of them no progression of disk degeneration was observed after implantation of the Accuflex system. Additionally, as demonstrated by the MRI images at follow up, three patients (16%) showed disk rehydration with one grade higher on the Pfirmann classification. Although a relatively high hardware failure was observed (22.22%), the use of the dynamic stabilization system Accuflex posterior to decompression procedures, showed clinical benefits and stopped the degenerative process in 83% the patients.
Dynamic spine stabilization; Spinal stenosis; Disk herniation; Disk regeneration; Dynamic rods
Degenerative spondylolisthesis (DS) is a disorder that causes the slip of one vertebral body over the one below due to degenerative changes in the spine. Lumbar DS is a major cause of spinal canal stenosis and is often related to low back and leg pain. We reviewed the symptoms, prognosis and conservative treatments for symptoms associated with DS. PubMed and MEDLINE databases (1950–2007) were searched for the key words “spondylolisthesis”, “pseudospondylolisthesis”, “degenerative spondylolisthesis”, “spinal stenosis”, “lumbar spine”, “antherolisthesis”, “posterolisthesis”, “low back pain”, and “lumbar instability”. All relevant articles in English were reviewed. Pertinent secondary references were also retrieved. The prognosis of patients with DS is favorable, however, those who suffer from neurological symptoms such as intermittent claudication or vesicorectal disorder, will most probably experience neurological deterioration if they are not operated upon. Nonoperative treatment should be the initial course of action in most cases of DS, with or without neurologic symptoms. Treatment options include use of analgesics and NSAIDs to control pain; epidural steroid injections, and physical methods such as bracing and flexion strengthening exercises. An up-to-date knowledge on diagnosis and prevention of lumbar DS can assist in determination of future research goals. Additional studies are required to establish treatment protocols for the conservative treatment of DS.
Degenerative spondylolisthesis; Diagnosis; Treatment; Lumbar spine
Background: Foraminal stenosis is an important cause of radicular and generalized back pain. In patients who do not respond to conservative interventions, endoscopic spinal surgery provides similar results to open surgical approaches with lower rates of complication, postoperative pain, and shorter duration of hospital stay.
Methods: We performed a prospective, open, uncontrolled trial of 64 patients to evaluate endoscopic laminoforaminoplasty for the treatment of refractory foraminal stenosis.
Results: Fifty-nine percent of patients had at least 75% improvement in Oswestry Disability Index (Oswestry) and Visual Analog Scale (VAS) scores. All patients were discharged the day of surgery. Dural leaks occurred in two patients, which were repaired intraoperatively. No other adverse events occurred.
Conclusions: Endoscopic laminoforaminoplasty appears to be a safe alternative to open decompression in patients with spinal foraminal stenosis; additional controlled trials are warranted.
endoscopic laminoforaminoplasty; spinal foraminal stenosis; minimally invasive surgery
To assess safety, risk factors and clinical outcomes in elderly patients with spinal stenosis after decompressive laminectomy.
A prospective cohort of patients 70 years and older with spinal stenosis undergoing conventional laminectomy without fusion (n = 101) were consecutively enrolled from regular clinical practice and reassessed at 3 and 12 months. Primary outcome was change in health related quality of life measured (HRQL) with EuroQol-5 D (EQ-5D). Secondary outcomes were safety assessment, changes in Oswestry disability index (ODI), Visual Analogue Scale (EQ-VAS) score for self reported health, VAS score for leg and back pain and patient satisfaction. We used regression analyses to evaluate risk factors for less improvement.
The mean EQ-5 D total score were 0.32, 0.63 and 0.60 at baseline, 3 months and 12 months respectively, and represents a statistically significant (P < 0.001) improvement. Effect size was > 0.8. Mean ODI score at baseline was 44.2, at 3 months 25.6 and at 27.9. This represents an improvement for all post-operative scores. A total of 18 (18.0%) complications were registered with 6 (6.0%) classified as major, including one perioperative death. Patients stating that the surgery had been beneficial at 3 months was 82 (89.1%) and at 12 months 73 (86.9%). The only predictor found was patients with longer duration of leg pain had less improvement in ODI (P < 0.001). Increased age or having complications did not predict a worse outcome in any of the outcome variables.
Properly selected patients of 70 years and older can expect a clinical meaningful improvement of HRQL, functional status and pain after open laminectomy without fusion. The treatment seems to be safe. However, patients with longstanding leg-pain prior to operation are less likely to improve one year after surgery.
Clinical interpretation of health services research based on administrative databases is limited by the lack of patient-reported functional outcome measures. Reoperation, as a surrogate measure for poor outcome, may be biased by preferences of patients and surgeons and may even be planned a priori. Other available administrative data outcomes, such as postoperative cross sectional imaging (PCSI), may better reflect changes in functional outcome. The purpose was to determine if postoperative events captured from administrative databases, namely reoperation and PCSI, reflect outcomes as derived by validated functional outcome measures (short form 36 scores, Oswestry disability index) for patients who underwent discretionary surgery for specific degenerative conditions of the lumbar spine such as disc herniation, spinal stenosis, degenerative spondylolisthesis, and isthmic spondylolisthesis. After reviewing the records of all patients surgically treated for disc herniation, spinal stenosis, degenerative spondylolisthesis, and isthmic spondylolisthesis at our institution, we recorded the occurrence of PCSI (MRI or CT-myelograms) and reoperations, as well as demographic, surgical, and functional outcome data. We determined how early (within 6 months) and intermediate (within 18 months) term events (PCSI and reoperations) were associated with changes in intermediate (minimum 1 year) and late (minimum 2 years) term functional outcome, respectively. We further evaluated how early (6–12 months) and intermediate (12–24 months) term changes in functional outcome were associated with the subsequent occurrence of intermediate (12–24 months) and late (beyond 24 months) term adverse events, respectively. From 148 surgically treated patients, we found no significant relationship between the occurrence of PCSI or reoperation and subsequent changes in functional outcome at intermediate or late term. Similarly, earlier changes in functional outcome did not have any significant relationship with subsequent occurrences of adverse events at intermediate or late term. Although it may be tempting to consider administrative database outcome measures as proxies for poor functional outcome, we cannot conclude that a significant relationship exists between the occurrence of PCSI or reoperation and changes in functional outcome.
Administrative data; Postoperative imaging; Reoperation; Functional outcome; Spine surgery
Two cases of dynamic lumbar spinal stenosis were identified by the authors using axial loaded magnetic resonance image (MRI). In both cases, the patients presented with neurogenic claudication but MRI in decumbency showed no definite pathologic condition associated with their symptoms. In contrast, axial loaded MRI demonstrated constrictive spinal stenosis and a significantly decreased dural sac caused by epidural fat buckling and thickening of the ligamentum flavum in both cases. In the second case, a more prominent disc protrusion was also demonstrated compared with decumbent MRI. After decompressive surgery, both patients had satisfactory outcomes. Axial loaded MRI can therefore give decisive information in dynamic spinal disorders by allowing simulation of an upright position.
Axial loaded MRI; Dynamic lumbar spinal stenosis; Neurogenic claudication
This study is a prospective, clinical study assessing the efficacy of selective decompression of the level responsible in a two-level stenosis in accordance with the neurological findings defined by the gait load test with a treadmill.
To clarify the clinical features of multilevel lumbar spinal stenosis (LSS) regarding the neurological level responsible for the symptoms, neurogenic claudication, and outcomes of selective decompression.
Overview of Literature
Most spine surgeons have reported that multilevel compression of the cauda equina induces a more severe impairment of the nerve function than a single-level compression. However, the clinical effects of multilevel LSS on the cauda equine and nerve roots are unknown.
A total of 21 patients with lumbar spinal canal stenosis due to spondylosis and degenerative spondylolisthesis were selected. The level responsible for the symptoms in the two-level stenosis was determined from the neurological findings on the gait load test and functional diagnosis based on a selective nerve root block. All patients underwent a prospective, selective decompression at the level neurologically responsible only. The average follow-up period was 2.6 years (range, 1 to 6 years). The postsurgical outcome was defined using the Visual Analogue Scale (VAS) at the post-gait load test, 2 weeks after surgery, 3 months after surgery and at the last follow up.
Before surgery, the mean threshold distance and mean walking tolerance was 34.3 m and 113 m, respectively. All patients had neurogenic claudication and 19 of the patients had cauda equina syndrome, including hypesthesia in 11 cases, muscle weakness in 5 cases and radicular pain in 7 cases. Selective nerve blocks to determine the level responsible for the lumbosacral symptoms in 2 cases revealed a mean VAS score of 7.1, 2.61, 3.04, and 3.47 at the post-gait load test, 2 weeks after surgery, 3 months after surgery and at the last follow up, respectively. All subjects underwent surgery. After the operation, neurogenic claudication with or without cauda equna syndrome subsided in all patients.
The gait load test allows an objective and quantitative evaluation of the gait characteristics of patients with lumbar canal stenosis and is useful for determining the appropriate level for surgical treatment.
Gait load test; Neurogenic claudication; Lumbar canal stenosis
Prospective Observational Cohorts
To describe sociodemographic and clinical features, and non-operative (medical) resource utilization prior to enrollment, in patients who are candidates for surgical intervention for intervertebral disc herniation (IDH), spinal stenosis (SpS), and degenerative spondylolisthesis (DS) according to SPORT criteria.
Summary of Background Data
Intervertebral disc herniation, spinal stenosis, and degenerative spondylolisthesis with stenosis are the three most common diagnoses of low back and leg symptoms for which surgery is performed. There is a paucity of descriptive literature examining large patient cohorts for the relationships among baseline characteristics and medical resource utilization with these three diagnoses.
The Spine Patient Outcomes Research Trial (SPORT) conducts three randomized and three observational cohort studies of surgical and non-surgical treatments for patients with IDH, SPS, and DS. Baseline data include demographic information, prior treatments received, and functional status measured by SF-36 and the Oswestry Disability Index (ODI-AAOS/Modems version). The data presented represents all 1,417 patients (745 IDH, 368 SpS, 304 DS) enrolled in the SPORT observational cohorts. Multiple logistic regression was used to generate independent predictors of utilization adjusted for sociodemographic variables, diagnosis, and duration of symptoms.
The average age was 41 years for the IDH group, 64 years for the SPS group, and 66 years for the DS group.
At enrollment, IDH patients presented with the most pain as reported on the SF-36 (BP 26.2 vs 33 SPS and 33.7 DS) and were the most impaired (ODI 51 vs 42.3 SPS and 41.5 DS). IDH patients utilized more chiropractic treatment (42% vs 33% SPS and 26% DS); had more Emergency Department (ED) visits (21% vs 7 % SPS and 4% DS); and used more opiate analgesics (50% vs 29% SPS and 28% DS).
After adjusting for age, gender, diagnosis, education, race, duration of symptoms, and compensation, Medicaid patients used significantly more opiate analgesics (58% Medicaid vs 41% no insurance, 42% employer, 33% Medicare, and 32% private) and had more ED visits compared to other insurance types. (31% Medicaid vs 22% no insurance, 16% employer, 3% Medicare, and 11% private).
IDH patients appear to have differences in sociodemographics, resource utilization, and functional impairment when compared to the SpS/DS patients. In addition, the differences in resource utilization for Medicaid patients may reflect differences in access to care. The data provided from these observational cohorts will serve as an important comparison to the SPORT randomized cohorts in the future.
SPORT; Disc herniation; spinal stenosis; degenerative spondylolisthesis; epidemiology; outcomes; utilization of healthcare resources