Surgery For Lumbar Stenosis Research Articles

Racial Disparities in the Outcomes of Surgery for Lumbar Stenosis

Racial Disparities in the Outcomes of Surgery for Lumbar Stenosis

Epidural fentanyl for postoperative analgesia after lumbar canal decompression: a randomized controlled trial

Postoperative back pain is common after decompression surgery for lumbar stenosis and often delays discharge from hospital. Achieving regional analgesia by intraoperative delivery of epidural opiates after lumbar canal decompression is a promising approach to reduce postoperative pain and enhance early mobilization. However, there have been concerns about opiate-related complications, such as respiratory depression and urinary retention in what is generally an elderly population of patients. To assess the analgesic efficacy of bolus epidural fentanyl administered intraoperatively after lumbar decompression for degenerative canal stenosis. Patient-blinded randomized controlled trial conducted at two university neurosurgical centers. Adults (older than 18 years) with neurogenic claudication and/or lower limb radiculopathy and concordant lumbar spinal canal stenosis demonstrated on magnetic resonance imaging. Patients with previous lumbar spinal surgery, a contraindication to fentanyl, or requiring instrumentation were excluded. The primary outcome measure was patient-reported Visual Analogue Score (VAS) for pain recorded preoperatively, in recovery, and on the first and second postoperative days if the patient remained in the hospital. Secondary outcomes were duration of surgery, length of stay, and any side effects or complications. Patients underwent a one to three level lumbar canal decompression as required, via a midline incision, under general anesthesia. Before wound closure either no drug (control) or a 100-μg bolus of fentanyl was administered via an epidural catheter inserted 10 cm rostral to the operated level. Patients were blinded to group allocation, and analysis was by intention to treat. The trial was approved by the National Health Service Research Ethics Service and the Medicines and Healthcare products Regulatory Agency. No commercial or other source of funding was received. Sixty patients were randomized, 29 to fentanyl and 31 to control. Demographics, duration of surgery, and preoperative VAS were not significantly different between the groups. VAS in recovery was significantly lower in patients treated with fentanyl (mean [standard deviation]: 2.6[2.7] vs. 4.7 [2.4]; p=.003). Later VAS and postoperative length of stay were similar between groups. More patients in the fentanyl group required temporary urinary catheterization, but there was no significant difference in the incidence of side effects. Bolus epidural fentanyl provides effective short-term postoperative analgesia after lumbar canal decompression and may be a useful adjunct to pain management in patients undergoing lumbar spine surgery.

Minimum clinically important difference in pain, disability, and quality of life after neural decompression and fusion for same-level recurrent lumbar stenosis: understanding clinical versus statistical significance

Spine surgery outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect, but the extent of improvement in the numerical scores of these questionnaires lacks a direct clinical meaning. Because of this, the concept of a minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of same-level recurrent stenosis following index lumbar fusion, which commonly requires revision decompression and fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for this pathology. In 53 consecutive patients undergoing revision surgery for same-level recurrent lumbar stenosis-associated back and leg pain, PRO measures of back and leg pain were assessed preoperatively and 2 years postoperatively, using the visual analog scale for back pain (VAS-BP) and leg pain (VAS-LP), Oswestry Disability Index (ODI), Physical and Mental Component Summary categories of the 12-Item Short Form Health Survey (SF-12 PCS and MCS) for quality of life, Zung Depression Scale (ZDS), and EuroQol-5D health survey (EQ-5D). Four established anchor-based MCID calculation methods were used to calculate MCID (average change; minimum detectable change; change difference; and receiver operating characteristic curve analysis) for 2 separate anchors (health transition index of the SF-36 and the satisfaction index). All patients were available for 2-year PRO assessment. Two years after surgery, a significant improvement was observed for all PROs assessed. The 4 MCID calculation methods generated a range of MCID values for each of the PROs (VAS-BP 2.2-6.0, VAS-LP 3.9-7.5, ODI 8.2-19.9, SF-12 PCS 2.5-12.1, SF-12 MCS 7.0-15.9, ZDS 3.0-18.6, and EQ-5D 0.29-0.52). Each patient answered synchronously for the 2 anchors, suggesting both of these anchors are equally appropriate and valid for this patient population. The same-level recurrent stenosis surgery-specific MCID is highly variable based on calculation technique. The "minimum detectable change" approach is the most appropriate method for calculation of MCIDs in this population because it was the only method to reliably provide a threshold above the 95% confidence interval of the unimproved cohort (greater than the measurement error). Based on this method, the MCID thresholds following neural decompression and fusion for symptomatic same-level recurrent stenosis are 2.2 points for VAS-BP, 5.0 points for VAS-LP, 8.2 points for ODI, 2.5 points for SF-12 PCS, 10.1 points for SF-12 MCS, 4.9 points for ZDS, and 0.39 QALYs for EQ-5D.

Use of Bone Morphogenetic Proteins in Spinal Fusion Surgery for Older Adults With Lumbar Stenosis

Retrospective cohort study of Medicare claims. Examine trends and patterns in the use of bone morphogenetic proteins (BMP) in surgery for lumbar stenosis; compare complications, reoperation rates, and charges for patients undergoing lumbar fusion with and without BMP. Small, randomized trials have demonstrated higher rates of solid fusion with BMP than with allograft bone alone, with few complications and, in some studies, reduced rates of revision surgery. However, complication and reoperation rates from large population-based cohorts in routine care are unavailable. We identified patients with a primary diagnosis of lumbar stenosis who had fusion surgery in 2003 or 2004 (n = 16,822). We identified factors associated with BMP use: major medical complications during the index hospitalization, rates of rehospitalization within 30 days, and rates of reoperation within 4 years of follow-up (through 2008). Use of BMP increased rapidly, from 5.5% of fusion cases in 2003 to 28.1% of fusion cases in 2008. BMP use was greater among patients with previous surgery and among those having complex fusion procedures (combined anterior and posterior approach, or greater than 2 disc levels). Major medical complications, wound complications, and 30-day rehospitalization rates were nearly identical with or without BMP. Reoperation rates were also very similar, even after stratifying by previous surgery or surgical complexity, and after adjusting for demographic and clinical features. On average, adjusted hospital charges for operations involving BMP were about $15,000 more than hospital charges for fusions without BMP, though reimbursement under Medicare's Diagnosis-Related Group system averaged only about $850 more. Significantly fewer patients receiving BMP were discharged to a skilled nursing facility (15.9% vs. 19.0%, P < 0.001). In this older population having fusion surgery for lumbar stenosis, uptake of BMP was rapid, and greatest among patients with prior surgery or having complex fusion procedures. BMP appeared safe in the perioperative period, with no increase in major medical complications. Use of BMP was associated with greater hospital charges but fewer nursing home discharges, and was not associated with reduced likelihood of reoperation.

Cost per quality-adjusted life year gained of revision neural decompression and instrumented fusion for same-level recurrent lumbar stenosis: defining the value of surgical intervention

Despite advances in technology and understanding in spinal physiology, reoperation for symptomatic same-level recurrent stenosis continues to occur. Although revision lumbar surgery is effective, attention has turned to the question of the utility and value of revision decompression and fusion procedures. To date, an analysis of cost and heath state gain associated with revision lumbar surgery for recurrent same-level lumbar stenosis has yet to be described. The authors set out to assess the 2-year comprehensive cost of revision surgery and determine its value in the treatment of same-level recurrent stenosis. Forty-two patients undergoing revision decompression and instrumented fusion for same-level recurrent stenosis-associated leg and back pain were included in this study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed. The mean (± SD) interval between prior and revision surgery was 4.16 ± 4.64 years. Bone morphogenetic protein was used in 7 cases of revision arthrodesis (16.7%). A mean cumulative 2-year gain of 0.84 QALY was observed after revision surgery. The mean total 2-year cost of revision fusion was $49,431 ± $7583 (surgery cost $21,060 ± $4459; outpatient resource utilization cost $9748 ± $5292; indirect cost $18,623 ± $9098). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $58,846. In the authors' practice, revision decompression and fusion provided a significant gain in health state utility for patients with symptomatic same-level recurrent stenosis, with a 2-year cost per QALY gained of $58,846. When indicated, revision surgery for same-level recurrent stenosis is a valuable treatment option for patients experiencing back and leg pain secondary to this disease. The authors' findings provide a value measure of surgery that can be compared with the results of future cost-per-QALY-gained studies of medical management or alternative surgical approaches.

Predictors of Reoperation in Lumbar Stenosis and Degenerative Spondylolisthesis Surgery: A Subgroup Analysis of the SPORT Study

smoking, diabetes, heart problems, intestinal problems, sensory deficit, L5S1 stenosis, neuroforaminal stenosis, predominant leg pain, and a job without lifting requirements predicted larger TEs in the minimally adjusted analyses. Multivariate analysis demonstrated that not smoking (TE 11.8 vs. 1.6 for smokers, p!.001), lower baseline ODI score (TE 16.3 for ODI!30 vs. 4.8 for ODIO56, p!.001), heart problems (TE 13.3 vs. 9.5 for patients without heart problems, p5.041), predominant leg pain (TE 11.5 vs. 7.3 for predominant back pain, p5.035), and a job without lifting (TE5-12.5 vs. 8.5 for a job with lifting, p5.017) were independent TE modifiers. CONCLUSIONS: SPORT SpS patients met specific inclusion criteria and improved more with surgery than with nonoperative treatment in all evaluated subgroups other than smokers. However, TE varied significantly among subgroups; non-smokers, patients with lower baseline ODI scores, heart problems, predominant leg pain, and a job without lifting benefited more from surgery relative to nonoperative treatment. Due to their poor surgical outcomes that were not significantly better than nonoperative outcomes, smokers with SpS should be advised that they may not substantially benefit from surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.

Error in Trends, Major Medical Complications, and Charges Associated With Surgery for Lumbar Spinal Stenosis in Older Adults

Context In recent decades, the fastest growth in lumbar surgery occurred in older patients with spinal stenosis. Trials indicate that for selected patients, decompressive surgery offers an advantage over nonoperative treatment, but surgeons often recommend more invasive fusion procedures. Comorbidity is common in older patients, so benefits and risks must be carefully weighed in the choice of surgical procedure. Objective To examine trends in use of different types of stenosis operations and the association of complications and resource use with surgical complexity. Design, Setting, and Patients Retrospective cohort analysis of Medicare claims for 2002-2007, focusing on 2007 to assess complications and resource use in US hospitals. Operations for Medicare recipients undergoing surgery for lumbar stenosis (n = 32 152 in the first 11 months of 2007) were grouped into 3 gradations of invasiveness: decompression alone, simple fusion (1 or 2 disk levels, single surgical approach), or complex fusion (more than 2 disk levels or combined anterior and posterior approach). Main Outcome Measures Rates of the 3 types of surgery, major complications, postoperative mortality, and resource use. Results Overall, surgical rates declined slightly from 2002-2007, but the rate of complex fusion procedures increased 15-fold, from 1.3 to 19.9 per 100 000 beneficiaries. Life-threatening complications increased with increasing surgical invasiveness, from 2.3% among patients having decompression alone to 5.6% among those having complex fusions. After adjustment for age, comorbidity, previous spine surgery, and other features, the odds ratio (OR) of life-threatening complications for complex fusion compared with decompression alone was 2.95 (95% confidence interval [CI], 2.50-3.49). A similar pattern was observed for rehospitalization within 30 days, which occurred for 7.8% of patients undergoing decompression and 13.0% having a complex fusion (adjusted OR, 1.94; 95% CI, 1.74-2.17). Adjusted mean hospital charges for complex fusion procedures were US $80 888 compared with US $23 724 for decompression alone. Conclusions Among Medicare recipients, between 2002 and 2007, the frequency of complex fusion procedures for spinal stenosis increased while the frequency of decompression surgery and simple fusions decreased. In 2007, compared with decompression, simple fusion and complex fusion were associated with increased risk of major complications, 30-day mortality, and resource use.

Posterior interbody fusion using a diagonal cage with unilateral transpedicular screw fixation for lumbar stenosis

Few reports have described the combined use of unilateral pedicle screw fixation and interbody fusion for lumbar stenosis. We retrospectively reviewed 79 patients with lumbar stenosis. The rationale and effectiveness of unilateral pedicle screw fixation were studied from biomechanical and clinical perspectives, aiming to reduce stiffness of the implant. All patients were operated with posterior interbody fusion using a diagonal cage in combination with unilateral transpedicular screw fixation and had reached the 3-year follow-up interval after operation. The mean operating time was 115 minutes (range = 95–150 min) and the mean estimated blood loss was 150 mL (range = 100–200 mL). The mean duration of hospital stay was 10 days (range = 7–15 days). Clinical outcomes were assessed prior to surgery and reassessed at intervals using Denis’ pain and work scales. Fusion status was determined from X-rays and CT scans. At the final follow-up, the clinical results were satisfactory and patients showed significantly improved scores ( p < 0.01) either on the pain or the work scale. Successful fusion was achieved in all patients. There were no new postoperative radiculopathies, or instances of malpositioned or fractured hardware. Posterior interbody fusion using a diagonal cage with unilateral transpedicular fixation is an effective treatment for decompressive surgery for lumbar stenosis.

Answer to the letter to the editor of Carl Hans Fürstenberg et al. (2010) concerning manuscript “transforaminal endoscopic surgery for lumbar stenosis: a systematic review” by Jorm Nellensteijn, Raymond Ostelo, Ronald Bartels, Wilco Peul, Barend Van Royen, Maurits Van Tulder. Eur Spine J 19:879–886

In the letter to the editor it is suggested that we might have missed relevant evidence. Not including ‘discectomy’ in the search strategy is pointed out as the main reason. But apparently there is confusion regarding the fact that we published two systematic reviews, both on transforaminal endoscopic surgery. One focuses on symptomatic lumbar disc herniations [1] and the second one on lumbar stenosis [2]. We combined the search strategy for these two reviews for efficiency reasons. The keywords were used as MESH headings and free text words; discectomy was included in the search strategy [1]. The full search strategy is available upon request. In the present review we focus on stenosis. The SCIATICA-Med trial [3, 4] included patients with lumbar disc herniation and was therefore not eligible for this review. Moreover, it clearly uses a different technique than the transforaminal endoscopic surgery. Therefore, this study was also excluded from our systematic review on symptomatic lumbar disc herniations [1]. The German health technology assessment report [5] focuses on the treatment of disc prolapse and not stenosis. The study by Hermantin et al. [6] met the inclusion criteria for review on symptomatic lumbar disc herniations [1] and was included (see Ref. 11 of that review). The report by the Dutch Health Care Insurance also focuses on lumbar disc herniation and was based on our review [1]. The three key publications [7–9] that we reportedly ‘omitted’ were included in our review on symptomatic lumbar disc herniations [1] as they included patients with lumbar disc herniation. The study by Molyneux was not found as our search strategy was up to November 2009. Conference proceedings did not meet our definition of ‘published papers’ and therefore Lewandrowski [10] and Iprenburg [11] were not included. The reference by Morgenstern [12] could not be retrieved, as the European Musculoskeletal Review seems not to be indexed in the databases we searched. The study by Hoogland [13] includes patients with recurrent lumbar disc herniation, not stenosis. In assessing the risk of bias, we followed the guidelines of the Cochrane Back Review Group and, therefore, we think that the doubt the authors convey regarding ‘the publication quality assessment criteria’ is without any foundation. In conclusion, no randomized controlled trial, but only seven observational studies were identified and no relevant papers are missed. All these studies had a high risk of bias. Consequently, the conclusion that there is no valid evidence on the effectiveness of transforaminal endoscopic surgery for lumbar stenosis is supported by the data.

Letter to the editor concerning “Transforaminal endoscopic surgery for lumbar stenosis: a systematic review” (Nellensteijn et al.)

The recently published systematic review by Nellensteijn et al. [1] has identified seven observational studies on the effectiveness of transforaminal endoscopic surgery for lumbar stenosis. The authors conclude that there is a lack of valid evidence supporting the intervention. We believe that there is more evidence in the literature than that found. Probably, this is due to the authors not including discectomy as a major key word in their search strategy (Table 1). First and foremost, there are at least three systematic reviews that provide additional data. Gibson and Waddell [2] refer to the SCIATICA-Med Trial [3, 4] and a German health technology assessment report [5] identified three RCTs and 12 case series between 1998 and 2004 focusing on endoscopically assisted minimally invasive disc surgery. None of these is duplicated in the Nellensteijn review and, most interestingly, a former review with the same title and group of authors funded by the Dutch Health Care Insurance Board, yielded 8 controlled studies and 31 cohort studies [6]. The 2010 Nellensteijn review has also omitted three key publications on the grounds of lacking focus on lumbar stenosis [7–9] and data from several observational studies focusing on foraminal treatment access [10–15]. These data should at least have been referred to when considering the potential effectiveness of transforaminal endoscopic surgery in a full text evaluation. In addition to criticisms regarding missing data, there is some doubt about whether or not the publication quality assessment criteria used by the authors are appropriate and state of the art, as there are established instruments [16, 17] for this purpose. It should also be noted that the Prisma Flow diagram is not used in the review [18], which further impairs the quality of the paper. We respectfully suggest that there should be better documentation of the study selection process with detailed reporting of reasons for inclusions and exclusions.

Anesthesia Literature Review

Anesthesia Literature Review

Trends, Major Medical Complications, and Charges Associated With Surgery for Lumbar Spinal Stenosis in Older Adults

In recent decades, the fastest growth in lumbar surgery occurred in older patients with spinal stenosis. Trials indicate that for selected patients, decompressive surgery offers an advantage over nonoperative treatment, but surgeons often recommend more invasive fusion procedures. Comorbidity is common in older patients, so benefits and risks must be carefully weighed in the choice of surgical procedure. To examine trends in use of different types of stenosis operations and the association of complications and resource use with surgical complexity. Retrospective cohort analysis of Medicare claims for 2002-2007, focusing on 2007 to assess complications and resource use in US hospitals. Operations for Medicare recipients undergoing surgery for lumbar stenosis (n = 32,152 in the first 11 months of 2007) were grouped into 3 gradations of invasiveness: decompression alone, simple fusion (1 or 2 disk levels, single surgical approach), or complex fusion (more than 2 disk levels or combined anterior and posterior approach). Rates of the 3 types of surgery, major complications, postoperative mortality, and resource use. Overall, surgical rates declined slightly from 2002-2007, but the rate of complex fusion procedures increased 15-fold, from 1.3 to 19.9 per 100,000 beneficiaries. Life-threatening complications increased with increasing surgical invasiveness, from 2.3% among patients having decompression alone to 5.6% among those having complex fusions. After adjustment for age, comorbidity, previous spine surgery, and other features, the odds ratio (OR) of life-threatening complications for complex fusion compared with decompression alone was 2.95 (95% confidence interval [CI], 2.50-3.49). A similar pattern was observed for rehospitalization within 30 days, which occurred for 7.8% of patients undergoing decompression and 13.0% having a complex fusion (adjusted OR, 1.94; 95% CI, 1.74-2.17). Adjusted mean hospital charges for complex fusion procedures were US $80,888 compared with US $23,724 for decompression alone. Among Medicare recipients, between 2002 and 2007, the frequency of complex fusion procedures for spinal stenosis increased while the frequency of decompression surgery and simple fusions decreased. In 2007, compared with decompression, simple fusion and complex fusion were associated with increased risk of major complications, 30-day mortality, and resource use.

Transforaminal endoscopic surgery for lumbar stenosis: a systematic review

Transforaminal endoscopic techniques have become increasingly popular in surgery of patients with lumbar stenosis. The literature has not yet been systematically reviewed. A comprehensive systematic literature review up to November 2009 to assess the effectiveness of transforaminal endoscopic surgery in patients with symptomatic lumbar stenosis was made. Two reviewers independently checked all retrieved titles and abstracts and relevant full text articles for inclusion criteria. Included articles were assessed for quality, and relevant data, including outcomes, were extracted by two reviewers independently. No randomized controlled trials were identified, but seven observational studies. The studies were of poor methodological quality and heterogeneous regarding patient selection, indications, operation techniques, follow-up period and outcome measures. Overall, 69–83% reported the outcome as satisfactory and a complication rate of 0–8.3%. The reported re-operation rate varied from 0 to 20%. At present, there is no valid evidence from randomized controlled trials on the effectiveness of transforaminal endoscopic surgery for lumbar stenosis. Randomized controlled trials comparing transforaminal endoscopic surgery with other surgical techniques are direly needed.

Functional and clinical evaluation for the surgical treatment of degenerative stenosis of the lumbar spinal canal

This study was designed to evaluate the efficacy of decompressive surgery for degenerative lumbar spinal stenosis (LSS) on a functional and clinical basis. A prospective analysis and follow-up of 125 consecutive patients with degenerative LSS between 2000 and 2006 were performed. All patients underwent surgery for lumbar stenosis. Functional evaluations of the patients were performed using a treadmill, the visual analog scale, and the Oswestry Disability Questionnaire (ODQ). These parameters were recorded before surgery and the 3rd month and 1st and 2nd years after treatment. The first symptom time (FST), maximal walking duration (MWD), and thecal sac cross-sectional area (CSA) before and after surgery were also recorded. Statistical relations between variables were calculated. As patient ages increased, the CSA of the thecal sac decreased. Decompressive surgery reached the target according to the difference between the preoperative and postoperative thecal sac CSA. A correlation between the CSA of the thecal sac and FST, and between the CSA of the thecal sac and MWD could not be established. There was a significant correlation between the FST and MWD, and a negative correlation could be established between the MWD and the ODQ score. Surgery led to significant decreases in the ODQ score. Maximal improvement was observed in the 3rd month after decompressive surgery. The treatment for LSS should be decided using functional criteria; radiological criteria may not correlate with the severity of the disease. Improvements following lumbar decompression surgery continued within 1 year of treatment according to the ODQ and did not change significantly thereafter.

Sacral Insufficiency Fracture, Usually Overlooked Cause of Lumbosacral Pain

Sacral insufficiency fractures are usually known to develop in elderly patients with osteoporosis without definite trauma history. It is difficult to diagnose the sacral insufficiency fracture at an early stage because lower lumbar diseases, concurrently or not, may also be presented with similar symptoms and signs. We report a rare case of sacral insufficiency fracture who was not diagnosed initially but, instead, showed progressively worsening of clinical symptoms and radiological findings after decompression surgery for upper level lumbar stenosis.

Revision Surgery for Lumbar Stenosis: Techniques, Results, and Complications

Revision surgery for lumbar stenosis is associated with longer surgical times, greater technical challenges, and a higher rate for potential complication rates than primary surgery. However, in well-selected patients, clinical success can be achieved. Identification of symptomatic residual or recurrent areas of stenosis or instability is paramount. Adhering to basic principles of revision surgery is crucial to its safe and effective execution. However, the surgeries are often far from “basic,” requiring the surgeon to be adept at a wide range of conventional and novel surgical techniques.

Health-related quality of life after surgical treatment for lumbar stenosis.

We performed a retrospective study using the Short Form-36 Health Survey questionnaire (SF-36), clinical examination, and neuroradiologic and neurophysiologic measurements. To evaluate patient outcomes, health-related quality of life (HRQoL), and clinical and neurophysiologic picture in a follow-up study of surgery for lumbar stenosis (LS). In LS patients, clinical, neuroradiologic, and neurophysiologic findings were not related with validated measurement of the outcomes that are more relevant to patients such as functional status and symptoms. Thirty patients surgically treated for LS were recontacted and evaluated by means of self-administered questionnaires (SF-36), clinical examination, and neuroradiologic and neurophysiologic measurements. Preoperative and follow-up clinical and neurophysiologic findings were registered. Relations between patient-oriented data and validated conventional clinical, neuroradiologic, and neurophysiologic measurements were evaluated. A comparison between preoperative and postoperative clinical picture shows an improvement of most parameters tested. A comparison between preoperative and postoperative neurophysiologic picture shows a worsening of most parameters tested. A comparison between the current sample and Italian normative data for the SF-36 shows a worsening of physical aspects of health-related quality of life; conversely, there is an improvement of some mental domains. Follow-up evaluation of surgical treatment for LS showed a mild impairment of physical aspects of HRQoL, as measured by patient-oriented evaluation. Clinical examination findings showed significant improvement. Conversely, neurophysiologic follow-up showed a discordant outcome. We think that, to better assess the surgical indication, further study should be performed focused on natural history and the association between neurophysiologic evolution and patient outcome, etc.

A predictive model for outcome after conservative decompression surgery for lumbar spinal stenosis.

This study was designed to develop predictive models for surgical outcome based on information available prior to lumbar stenosis surgery. Forty patients underwent decompressive laminarthrectomy. Preop and 1-year postop evaluation included Waddell's nonorganic signs, CT scan, Waddell disability index, Oswestry low back pain disability questionnaire, low back outcome score (LBOS), visual analog scale (VAS) for pain intensity, and trunk strength testing. Statistical comparisons of data used adjusted error rates within families of predictors. Mathematical models were developed to predict outcome success using stepwise logistic regression and decision-tree methodologies (chi-squared automatic interaction detection, or CHAID). Successful outcome was defined as improvement in at least three of four criteria: VAS, LBOS, and reductions in claudication and leg pain. Exact logistic regression analysis resulted in a three-predictor model. This model was more accurate in predicting unsuccessful outcome (negative predictive value 75.0%) than in successful outcome (positive predictive value 69.6%). A CHAID model correctly classified 90.1% of successful outcomes (positive predictive value 85.7%, negative predictive value 100%). The use of conservative surgical decompression for lumbar stenosis can be recommended, as it demonstrated a success rate similar to that of more invasive techniques. Given its physiologic and biomechanical advantages, it can be recommended as the surgical method of choice in this indication. Underlying subclinical vascular factors may be involved in the complaints of spinal stenosis patients. Those factors should be investigated more thoroughly, as they may account for some of the failures of surgical relief. The CHAID decision tree appears to be a novel and useful tool for predicting the results of spinal stenosis surgery

Rates of advanced spinal imaging and spine surgery.

Small area analysis. To determine the association between the rates of advanced spinal imaging and spine surgery across geographic areas. The rates of spine surgery in the United States have increased along with a concurrent rise in the use of advanced spinal imaging: CT and MRI. Spine surgery rates vary six-fold across geographic areas of the United States. Differences in patient populations and health care supply have explained only about 10% of this variation. We used a random 5% sample of Medicare's National Claims History Part B files for 1996 and 1997 to determine procedure rates across 306 Hospital Referral Regions. We analyzed the association between spinal imaging and spine surgery using linear regression. Main outcome measures were rates of procedures and coefficients of determination (R2). The rates of advanced spinal imaging (CT and MRI combined) varied 5.5-fold across geographic areas. Areas with higher rates of MRI had higher rates of spine surgery overall (r = 0.46) and spinal stenosis surgery specifically (r = 0.37). The rates of advanced spinal imaging accounted for 22% of the variability in overall spine surgery rates (R2 = 0.22, P < 0.001) and 14% of the variability in lumbar stenosis surgery rates (R2 = 0.14, P < 0.001). A simulation model showed that MRIs obtained in the patients undergoing surgery accounted for only a small part of the correlation between MRI and total spine surgery rates. A significant proportion of the variation in rates of spine surgery can be explained by differences in the rates of advanced spinal imaging. The indications for advanced spinal imaging are not firmly agreed on, and the appropriateness of many of these imaging studies has been questioned. Improved consensus on the use and interpretation of advanced spinal imaging studies could have an important effect on variation in spine surgery rates.

Complications associated with lumbar stenosis surgery in patients older than 75 years of age

An aging population will require that surgeons increasingly consider operative intervention in elderly patients. To perform this surgery safely will require an understanding of the factors that predict successful outcomes as well as complications. Records of patients older than the age of 75 years who underwent lumbar spinal stenosis surgery were retrospectively reviewed. Preexisting medical illnesses were analyzed using the Charlson Weighted Comorbidity Index. Ambulatory function was rated on a four-point scale. Statistical analysis was performed using a one-tailed t-test with unpaired variance. Eighty-eight patients treated between 1994 and 2001 were identified. Forty-five percent were women and 52 patients underwent spinal fusion. The follow-up period averaged 21 months. Back pain was present preoperatively in 89%; after surgery 43% experienced complete relief and 33% partial improvement. Leg pain was present preoperatively in 98%; after surgery 43% experienced complete relief and 42% partial improvement. Of the 33 patients with preoperative gait disturbances, 61% improved at least one point on the ambulatory scale. Wound complications and systemic complications were demonstrated in 24 and 16 patients, respectively. There were no deaths. Age (p = 0.322), number of fused levels (p = 0.371), and the number of laminectomy levels (p = 0.254) were not predictive of complications. Length of operative time (p = 0.003) and the Charlson Weighted Comorbidity Index score (p = 0.088) were associated with both systemic and wound complications. Surgery in patients older than age 75 years can be conducted safely and with similar outcome rates as in younger patients. The Charlson Weighted Comorbidity Index score and operative time were predictive of the risk of complications.