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

Can Discharge Radiographs Predict Junctional Complications? A Decision Tree Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To determine if standing pre-discharge radiographs can predict the development of junctional complications.

MATERIALS AND METHODS

Adult spinal deformity patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) were included. All patients underwent full-length standing radiographs before hospital discharge. Outcomes of interest included 2-year radiographic PJK and proximal junctional failure (PJF). Patients were stratified into 3 exclusive groups: No PJK, PJK, and PJF. Chi-square automatic interaction detection (CHAID) decision tree analysis was utilized to identify pre-discharge proximal junctional angle (PJA) thresholds associated with increased risk of PJK or PJF.

RESULTS

The 117 study patients had a mean age 65.8 ± 8.5, BMI 27.2 ± 4.9, PI-LL 23.3 ± 17.4, TPA 27.2 ± 11.5. Sample was stratified into 64 (54.7%) No PJK, 39 (33.3%) PJK, 14 (12.0%) PJF. No differences were detected between cohorts in discharge alignment, preop-discharge change, or offset from age-adjusted alignment targets (P > .005). Decision tree analysis showed that the first branch point depended on the UIV, as most patients with an UT UIV did not develop PJK or PJF (no PJK, 67.4%). For patients with an LT UIV, a second branch point occurred based on the ΔPJA. 89.5% of LT patients with a ΔPJA < 4.3° were free of radiographic PJK and PJF. The third branch point occurred based on the PJA at discharge. Thus, the highest risk group was comprised of ΔPJA ≥4.3° and PJA > 15.5°, as 57.1% of developed PJF and 28.6% PJK.

CONCLUSION

Most patients with a lower thoracic UIV, preop-discharge ΔPJA ≥4.3°, and discharge PJA > 15.5° develop PJF.

Impact of Preoperative Symptom Duration on Patient-reported Outcomes After Minimally Invasive Transforaminal Interbody Fusion for Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess the impact of preoperative symptom duration (PSD) on patient-reported outcome measures (PROMs) after minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis (DSpond).

BACKGROUND

A prolonged duration of preoperative symptoms may implicate inferior long-term outcomes postsurgery. Prior studies of lumbar fusion recipients are limited by the inclusion of heterogeneous populations.

METHODS

A single-surgeon registry was retrospectively queried for privately insured patients who had undergone primary, elective, single-level MIS-TLIF for DSpond with a recorded symptom start date. Cohorts were formed by PSD: shorter duration (PSD <1 y) or greater duration (GD; PSD ≥1 y). PROMs evaluated included Patient-reported Outcomes Measurement Information System-Physical Function, Oswestry Disability Index, Visual Analog Scale-Back, Visual Analog Scale-Leg, and 9-item Patient Health Questionnaire. The magnitude of PROM (∆PROM) improvement from preoperative baseline to 6 weeks and final follow-up (∆PROM-FF) were compared between cohorts. Intercohort achievement rates of a minimum clinically important difference in each PROM were compared.

RESULTS

A total of 133 patients included 85 patients with GD cohort. There were no significant differences in pre hoc demographics and perioperative characteristics between cohorts, as well as preoperative, 6-week, or final follow-up PROMs between cohorts. Both cohorts demonstrated significant improvement in all PROMs at 6 weeks and final follow-up (P ≤ 0.049, all). There were no significant intercohort differences demonstrated in minimum clinically important difference achievement rates, ∆PROM-6W, or ∆PROM-FF in any PROM.

CONCLUSIONS

Regardless of the symptom duration before MIS-TLIF for DSpond, patients demonstrate significant improvement in physical function, pain, disability, and mental health. Patients with a GD of preoperative symptoms did not report inferior scores in any PROM domain. Patients with a GD of preoperative symptoms did not suffer inferior rates of clinically meaningful improvement after surgical intervention. These findings should be considered when counseling patients before surgical intervention for DSpond.

The Impact of Preoperative Adaptive Training on Postoperative Outcomes in Lumbar Spine Fusion Surgery for Lumbar Disc Herniation: A Retrospective Analysis

Purpose

Lumbar disc herniation, often treated with surgical decompression when conservative measures fail, presents challenges due to prolonged prone positioning in surgeries. This retrospective study evaluates the benefits of preoperative adaptive training to mitigate post-surgical physiological changes.

Patients and Methods

A review of medical records from June 2021 to March 2023 identified 170 patients unresponsive to conservative treatments. Grouped into adaptive training and control groups based on historical data, the former had undergone exercises to prepare for surgery and postoperative changes. Vital signs and VAS scores were extracted from patient records to assess training impact.

Results

The adaptive training group demonstrated stabilized vital signs intraoperatively, with a notable improvement in surgical exposure compared to the control group. However, there were no significant differences in operative time or blood loss between the groups. Additionally, postoperative VAS scores showed no significant improvement in the adaptive training group at follow-up intervals of 14 days, 1 month, and 3 months post-operation, compared to the control group.

Conclusion

Our study reveals that preoperative adaptive training stabilizes intraoperative blood pressure fluctuations in lumbar disc herniation surgeries. However, this stabilization does not significantly impact long-term postoperative pain management. This highlights the need for further research to explore comprehensive strategies that effectively combine preoperative training with postoperative care.

Depressed patients with greater symptom duration before MIS-TLIF do not report inferior outcomes

PURPOSE

Patients with preoperative depressive symptoms may demonstrate inferior patient-reported outcomes (PROs). The effect of preoperative symptom duration (SD) on PROs in this population has not been well-studied. We aim to assess the influence of preoperative SD on PROs in patients with low mental health scores prior to minimally invasive transforaminal interbody fusion (MIS-TLIF).

METHODS

Patients who had undergone elective, primary MIS-TLIF with preoperative SF-12 MCS score below 45.6, a previously established threshold for depression, were selected. Patients were divided into matched lesser duration (LD; SD<365 days) and greater duration (GD; SD≥365 days) cohorts. PROs were collected preoperatively and at 6-week/12-week/6-month/1-year postoperative periods. PROs included PROMIS-PF/ODI/VAS back/VAS leg/SF-12 MCS. PROs were compared within and between groups. Rates of achievement of minimal clinically important difference (MCID) were compared between groups.

RESULTS

One hundred twenty-two patients were included after matching cohorts. Patients in the LD cohort demonstrated improvement in PROMIS-PF at 12-weeks/6-month/1-year, and ODI/VAS back/VAS leg/SF-12 MCS at all postoperative periods (p≤0.024, all). Patients in the GD cohort demonstrated improvement in PROMIS-PF at 12-weeks/6-month/1-year, and ODI/VAS back/VAS leg/SF-12 MCS at all postoperative periods (p≤0.013, all). There were no differences in PROs or MCID achievement between cohorts at any period.

CONCLUSION

Patients with preoperative depressive symptoms undergoing MIS-TLIF, regardless of duration of preoperative symptoms, demonstrated improvements in physical function, disability, pain, and mental health domains. Patients with greater duration of preoperative symptoms did not report inferior outcomes at any period. Rates of clinically important improvements in all domains were favorable and similar between cohorts.

Predictors for clinical outcomes of tubular surgery for endoscopic decompression in selected patients with lumbar spinal stenosis

INTRODUCTION

The success rate of decompression surgery for lumbar spinal stenosis (LSS) has been reported to vary from 60 to 80%. The purpose of this study was to analyze the predictors for clinical outcomes after tubular surgery for endoscopic decompression (microendoscopic decompression) for LSS.

MATERIALS AND METHODS

A total of 100 patients with degenerative LSS (M/F: 61/39, Age: mean 69.7 years), who underwent microendoscopic decompression and had a minimum 2-year follow-up (FU) after surgery, were reviewed. All patients suffered from leg-related symptoms predominantly without severe mechanical back pain, preoperatively. The presence of chronic arterial occlusion of the lower limbs was ruled out. The primary outcome measure was clinical evaluation at 2-year FU using the Oswestry Disability Index (ODI). Furthermore, numeric rating scales, Japanese Orthopedic Association (JOA) lumbar score and JOA Back Pain Evaluation Questionnaire were used for secondary outcome measures. Based on findings of univariable analyses, multivariable logistic regression analysis was applied to identify preoperative predictors for the clinical outcomes.

RESULTS

Sixty-eight patients (68%) were assessed as good outcomes, on the basis of minimum clinically important difference of the ODI (13 points ≤) and final ODI score (< 30 points). The secondary outcomes were further support for the primary outcome. In multivariable logistic regression analysis, co-existence of intradiscal vacuum phenomenon with LSS (odds ratio [OR] 8.26; 95% confidence interval [95% CI] 2.32-29.34; p = 0.001) and ischemic cardiovascular comorbidities (OR, 13.3; 95% CI, 1.9-92.57; p = 0.009) were significantly associated with poor clinical outcomes.

CONCLUSIONS

We found co-existence of intradiscal vacuum phenomenon with LSS and ischemic cardiovascular comorbidity to be preoperative predictors of less favorable clinical outcomes after microendoscopic decompression in selected patients of LSS. Although the conclusion obtained from restricted state, the information would be able to help in patient selection of the tubular surgery for endoscopic decompression for LSS.

Prediction Models in Degenerative Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

To review the existing literature of prediction models in degenerative spinal surgery.

METHODS

Review of PubMed/Medline and Embase databases was conducted to identify articles between January 1, 2000 and March 1, 2020 that reported prediction model performance for outcomes following elective degenerative spine surgery.

RESULTS

Thirty-one articles were included. Twenty studies were of thoracolumbar, 5 were of cervical, and 6 included all spine patients. Five studies were externally validated. Prediction models were developed using machine learning (42%) and logistic regression (42%) as well as other techniques. Web-based calculators were included in 45% of published articles. Various outcomes were investigated, including complications, infection, length of stay, discharge disposition, reoperation, readmission, disability score, back pain, leg pain, return to work, and opioid dependence.

CONCLUSIONS

Significant heterogeneity exists in methods used to develop prediction models of postoperative outcomes after degenerative spine surgery. Most internally validate their scores, but a few have been externally validated. Areas under the curve for most models range from 0.6 to 0.9. Techniques for development are becoming increasingly sophisticated with different machine learning tools. With further external validation, these models can be deployed online for patient, physician, and administrative use, and have the potential to optimize outcomes and maximize value in spine surgery.

Development of a model to predict the probability of incurring a complication during spine surgery

PURPOSE

Predictive models in spine surgery are of use in shared decision-making. This study sought to develop multivariable models to predict the probability of general and surgical perioperative complications of spinal surgery for lumbar degenerative diseases.

METHODS

Data came from EUROSPINE's Spine Tango Registry (1.2012-12.2017). Separate prediction models were built for surgical and general complications. Potential predictors included age, gender, previous spine surgery, additional pathology, BMI, smoking status, morbidity, prophylaxis, technology used, and the modified Mirza invasiveness index score. Complete case multiple logistic regression was used. Discrimination was assessed using area under the receiver operating characteristic curve (AUC) with 95% confidence intervals (CI). Plots were used to assess the calibration of the models.

RESULTS

Overall, 23'714/68'111 patients (54.6%) were available for complete case analysis: 763 (3.2%) had a general complication, with ASA score being strongly predictive (ASA-2 OR 1.6, 95% CI 1.20-2.12; ASA-3 OR 2.98, 95% CI 2.19-4.07; ASA-4 OR 5.62, 95% CI 3.04-10.41), while 2534 (10.7%) had a surgical complication, with previous surgery at the same level being an important predictor (OR 1.9, 95%CI 1.71-2.12). Respectively, model AUCs were 0.74 (95% CI, 0.72-0.76) and 0.64 (95% CI, 0.62-0.65), and calibration was good up to predicted probabilities of 0.30 and 0.25, respectively.

CONCLUSION

We developed two models to predict complications associated with spinal surgery. Surgical complications were predicted with less discriminative ability than general complications. Reoperation at the same level was strongly predictive of surgical complications and a higher ASA score, of general complications. A web-based prediction tool was developed at https://sst.webauthor.com/go/fx/run.cfm?fx=SSTCalculator .

SpineCloud: image analytics for predictive modeling of spine surgery outcomes

Purpose: Data-intensive modeling could provide insight on the broad variability in outcomes in spine surgery. Previous studies were limited to analysis of demographic and clinical characteristics. We report an analytic framework called "SpineCloud" that incorporates quantitative features extracted from perioperative images to predict spine surgery outcome. Approach: A retrospective study was conducted in which patient demographics, imaging, and outcome data were collected. Image features were automatically computed from perioperative CT. Postoperative 3- and 12-month functional and pain outcomes were analyzed in terms of improvement relative to the preoperative state. A boosted decision tree classifier was trained to predict outcome using demographic and image features as predictor variables. Predictions were computed based on SpineCloud and conventional demographic models, and features associated with poor outcome were identified from weighting terms evident in the boosted tree. Results: Neither approach was predictive of 3- or 12-month outcomes based on preoperative data alone in the current, preliminary study. However, SpineCloud predictions incorporating image features obtained during and immediately following surgery (i.e., intraoperative and immediate postoperative images) exhibited significant improvement in area under the receiver operating characteristic (AUC): AUC = 0.72 ( CI 95 = 0.59 to 0.83) at 3 months and AUC = 0.69 ( CI 95 = 0.55 to 0.82) at 12 months. Conclusions: Predictive modeling of lumbar spine surgery outcomes was improved by incorporation of image-based features compared to analysis based on conventional demographic data. The SpineCloud framework could improve understanding of factors underlying outcome variability and warrants further investigation and validation in a larger patient cohort.

Development of a Preoperative Predictive Model for Reaching the Oswestry Disability Index Minimal Clinically Important Difference for Adult Spinal Deformity Patients

STUDY DESIGN

Retrospective review of prospective multicenter adult spinal deformity (ASD) database.

OBJECTIVE

To create a model based on baseline demographic, radiographic, health-related quality of life (HRQOL), and surgical factors that can predict patients meeting the Oswestry Disability Index (ODI) minimal clinically important difference (MCID) at the two-year postoperative follow-up.

SUMMARY OF BACKGROUND DATA

Surgical correction of ASD can result in significant improvement in disability as measured by ODI, with the goal of reaching at least one MCID. However, a predictive model for reaching MCID following ASD correction does not exist.

METHODS

ASD patients ≥18 years and baseline ODI ≥ 30 were included. Initial training of the model comprised forty-three variables including demographic data, comorbidities, modifiable surgical variables, baseline HRQOL, and coronal/sagittal radiographic parameters. Patients were grouped by whether or not they reached at least one ODI MCID at two-year follow-up. Decision trees were constructed using the C5.0 algorithm with five different bootstrapped models. Internal validation was accomplished via a 70:30 data split for training and testing each model, respectively. Final predictions from the models were chosen by voting with random selection for tied votes. Overall accuracy, and the area under a receiver operating characteristic curve (AUC) were calculated.

RESULTS

198 patients were included (MCID: 109, No-MCID: 89). Overall model accuracy was 86.0%, with an AUC of 0.94. The top 11 predictors of reaching MCID were gender, Scoliosis Research Society (SRS) activity subscore, back pain, sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis mismatch (PI-LL), primary version revision, T1 spinopelvic inclination angle (T1SPI), American Society of Anesthesiologists (ASA) grade, T1 pelvic angle (T1PA), SRS pain, SRS total.

CONCLUSIONS

A successful model was built predicting ODI MCID. Most important predictors were not modifiable surgical parameters, indicating that baseline clinical and radiographic status is a critical factor for reaching ODI MCID.

LEVEL OF EVIDENCE

Level II.

Variability in the utility of predictive models in predicting patient-reported outcomes following spine surgery for degenerative conditions: a systematic review

OBJECTIVE

There is increasing emphasis on patient-reported outcomes (PROs) to quantitatively evaluate quality outcomes from degenerative spine surgery. However, accurate prediction of PROs is challenging due to heterogeneity in outcome measures, patient characteristics, treatment characteristics, and methodological characteristics. The purpose of this study was to evaluate the current landscape of independently validated predictive models for PROs in elective degenerative spinal surgery with respect to study design and model generation, training, accuracy, reliability, variance, and utility.

METHODS

The authors analyzed the current predictive models in PROs by performing a search of the PubMed and Ovid databases using PRISMA guidelines and a PICOS (participants, intervention, comparison, outcomes, study design) model. They assessed the common outcomes and variables used across models as well as the study design and internal validation methods.

RESULTS

A total of 7 articles met the inclusion criteria, including a total of 17 validated predictive models of PROs after adult degenerative spine surgery. National registry databases were used in 4 of the studies. Validation cohorts were used in 2 studies for model verification and 5 studies used other methods, including random sample bootstrapping techniques. Reported c-index values ranged from 0.47 to 0.79. Two studies report the area under the curve (0.71–0.83) and one reports a misclassification rate (9.9%). Several positive predictors, including high baseline pain intensity and disability, demonstrated high likelihood of favorable PROs.

CONCLUSIONS

A limited but effective cohort of validated predictive models of spine surgical outcomes had proven good predictability for PROs. Instruments with predictive accuracy can enhance shared decision-making, improve rehabilitation, and inform best practices in the setting of heterogeneous patient characteristics and surgical factors.

Study-protocol for a randomized controlled trial comparing clinical and radiological results after three different posterior decompression techniques for lumbar spinal stenosis: the Spinal Stenosis Trial (SST) (part of the NORDSTEN Study)

Background

There are several posterior decompression techniques for lumbar spinal stenosis (LSS). There is a trend towards performing less invasive surgical procedures, but no multicentre randomized controlled trials have evaluated the relative efficacy of these techniques at short and long-term.

Method/design

A multicentre randomized controlled trial [the Spinal Stenosis Trial (SST) (part of the NORDSTEN study)] including 465 patients aged 18–80 years with neurogenic claudication or radiating pain and MRI findings indicating lumbar spinal stenosis without spondylolisthesis is performed to compare three posterior decompression techniques: unilateral laminotomy with crossover, bilateral laminotomy and spinous process osteotomy. The primary outcome is change in Oswestry Disability Index (ODI 2 years postoperatively). Secondary outcomes are change in EQ-5D, Zurich Claudication Questionnaire, and Numeric Rating Scale for leg-pain and back-pain. Also recorded were Global Perceived Effect score, complications, length of hospital stay, reoperation rate 2 years postoperatively, difference in recurrence of symptoms or postoperative instability, and MRI change in the dural sac area. Further, a 5 and 10 years follow-up is planned with the same outcome measures.

Discussion

Newer and less invasive techniques are increasingly favoured in surgery for LSS. This trial will compare the clinical and radiological results of three different techniques, and may contribute to better clinical decision making in the surgical treatment of LSS.

Trial registration

ClinicalTrials.gov reference: NCT02007083 (November 22, 2013).

Development of Validated Computer-based Preoperative Predictive Model for Proximal Junction Failure (PJF) or Clinically Significant PJK With 86% Accuracy Based on 510 ASD Patients With 2-year Follow-up

STUDY DESIGN

A retrospective review of large, multicenter adult spinal deformity (ASD) database.

OBJECTIVE

The aim of this study was to build a model based on baseline demographic, radiographic, and surgical factors that can predict clinically significant proximal junctional kyphosis (PJK) and proximal junctional failure (PJF).

SUMMARY OF BACKGROUND DATA

PJF and PJK are significant complications and it remains unclear what are the specific drivers behind the development of either. There exists no predictive model that could potentially aid in the clinical decision making for adult patients undergoing deformity correction.

METHODS

Inclusion criteria: age ≥18 years, ASD, at least four levels fused. Variables included in the model were demographics, primary/revision, use of three-column osteotomy, upper-most instrumented vertebra (UIV)/lower-most instrumented vertebra (LIV) levels and UIV implant type (screw, hooks), number of levels fused, and baseline sagittal radiographs [pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA)]. PJK was defined as an increase from baseline of proximal junctional angle ≥20° with concomitant deterioration of at least one SRS-Schwab sagittal modifier grade from 6 weeks postop. PJF was defined as requiring revision for PJK. An ensemble of decision trees were constructed using the C5.0 algorithm with five different bootstrapped models, and internally validated via a 70 : 30 data split for training and testing. Accuracy and the area under a receiver operator characteristic curve (AUC) were calculated.

RESULTS

Five hundred ten patients were included, with 357 for model training and 153 as testing targets (PJF: 37, PJK: 102). The overall model accuracy was 86.3% with an AUC of 0.89 indicating a good model fit. The seven strongest (importance ≥0.95) predictors were age, LIV, pre-operative SVA, UIV implant type, UIV, pre-operative PT, and pre-operative PI-LL.

CONCLUSION

A successful model (86% accuracy, 0.89 AUC) was built predicting either PJF or clinically significant PJK. This model can set the groundwork for preop point of care decision making, risk stratification, and need for prophylactic strategies for patients undergoing ASD surgery.

LEVEL OF EVIDENCE

3.

An Outcome Measure of Functionality and Pain in Patients with Low Back Disorder: A Validation Study of the Iranian version of Low Back Outcome Score

Study Design

Cross-sectional study.

Purpose

This study aimed to cross-culturally translate and validate the low back outcome score (LBOS) in Iran.

Overview of Literature

Lumbar disc hernia (LDH) is the most common diagnoses of low back pain and imposes a heavy burden on both individual and society. Instruments measuring patient reported outcomes should satisfy cetain psychometric properties.

Methods

The translation and cross-cultural adaptation of the original questionnaire was performed using Beaton's guideline. A total of 163 patients with LDH were asked to respond to the questionnaire at three points in time: preoperative and twice within 1-week interval after surgery assessments. The Oswestry disabilty index (ODI) was also completed. The internal consistency, test-retest, convergent validity, and responsiveness to change were assessed. Responsiveness to change also was assessed comparing patients' pre- and postoperative scores.

Results

The mean age of the cohort was 49.8 years (standard deviation=10.1). The Cronbach's alpha coefficients for the LBOS at preoperative and postoperative assessments ranged from 0.77 to 0.79, indicating good internal consistency. Test-retest reliability as performed by intraclass correlation coefficient was found to be 0.82 (0.62–0.91). The instrument discriminated well between sub-groups of patients who differed in the Finneson-Cooper score. The ODI correlated strongly with the LBOS score, lending support to its good convergent validity (r=––0.83; p<0.001). Further analysis also indicated that the questionnaire was responsive to change (p<0.001).

Conclusions

The Iranian version of LBOS performed well and the findings suggest that it is a valid measure of back pain treatment evaluation among LDH patients.

Predictive modeling of complications

Predictive analytic algorithms are designed to identify patterns in the data that allow for accurate predictions without the need for a hypothesis. Therefore, predictive modeling can provide detailed and patient-specific information that can be readily applied when discussing the risks of surgery with a patient. There are few studies using predictive modeling techniques in the adult spine surgery literature. These types of studies represent the beginning of the use of predictive analytics in spine surgery outcomes. We will discuss the advancements in the field of spine surgery with respect to predictive analytics, the controversies surrounding the technique, and the future directions.

Does the wait for lumbar degenerative spinal stenosis surgery have a detrimental effect on patient outcomes? A prospective observational study

BACKGROUND

Waits for elective spine surgery are common in Canada. We examined whether a prolonged wait for surgery for lumbar degenerative spinal stenosis was detrimental to outcome.

METHODS

In this prospective observational study, we enrolled 166 consecutive patients referred to our centre for treatment of lumbar degenerative spinal stenosis between 2006 and 2010. Outcome measures were assessed at referral, preoperatively and until 24 months postoperatively. Primary outcome measures were the physical and mental component summary scores of the 36-Item Short-Form Health Survey and the Oswestry Disability Index. Secondary outcome measures included the symptom severity scale of the Zurich Claudication Questionnaire, a numeric rating scale for back and leg pain, and patient satisfaction with treatment. Wait time was defined as the time from referral to surgery.

RESULTS

The follow-up rate at 2 years was 85%. The median wait time was 349 days. All health-related quality of life measures deteriorated during the waiting period, but there was no significant correlation between wait time and magnitude of the change in outcome measure. At 6 months postoperatively, the Pearson correlation was significantly positive between wait time and change in disability (r = 0.223), Zurich Claudication Questionnaire score (r = 0.2) and leg pain score (r = 0.221). At 12 months, the correlation remained significant for change in disability (r = 0.205) and was significant for change in mental well-being (r = -0.224). At 12 months, patients with a shorter wait (≤ 12 months) showed greater improvement in mental well-being (mean difference in change [and 95% confidence interval (CI)] 5.7 [1.4-9.9]) and decrease in disability (-9.3 [95% CI -15.1 to -3.6]) and leg pain (-1.6 [95% CI -3.0 to -0.3]). There were no statistically significant differences in outcome or patient satisfaction with treatment between those with shorter and longer waits at 24 months.

INTERPRETATION

Patients awaiting spinal surgery experienced deterioration in health-related quality of life irrespective of the length of wait time. However, longer waits were associated with a delay in recovery during the first year after surgery.

Affective disorders influence clinical outcomes after revision lumbar surgery in elderly patients with symptomatic adjacent-segment disease, recurrent stenosis, or pseudarthrosis

Object

Depression and persistent low-back pain (LBP) are common and disabling problems in elderly patients (> 65 years old). Affective disorders, such as depression and anxiety, are also common in elderly patients, with a prevalence ranging from 4% to 16%. Depressive symptoms are consistently associated with functional disability. To date, few studies have assessed the predictive value of baseline depression on outcomes in the setting of revision spine surgery in elderly patients. Therefore, in this study, the authors assessed the predictive value of preoperative depression on 2-year postoperative outcomes.

Methods

A total of 69 patients undergoing revision neural decompression and instrumented fusion for adjacent-segment disease (ASD, n = 28), pseudarthrosis (n = 17), or same-level recurrent stenosis (n = 24) were included in this study. Preoperative Zung Self-Rating Depression Scale (ZDS) scores were assessed for all patients. Preoperative and 2-year postoperative visual analog scale (VAS) scores for back pain (VAS-BP) and leg pain (VAS-LP) and the Oswestry Disability Index (ODI) were also assessed. The association between preoperative ZDS score and 2-year improvement in disability was assessed via multivariate regression analysis.

Results

Compared with preoperative status, 2-year postoperative VAS-BP was significantly improved after surgery for ASD (9 ± 2 vs 4.01 ± 2.56, respectively; p = 0.001), as were pseudarthrosis (7.41 ± 1 vs 5.0 ± 3.08, respectively; p = 0.02) and same-level recurrent stenosis (7 ± 2.00 vs 5.00 ± 2.34, respectively; p = 0.003). Two-year ODI was also significantly improved after surgery for ASD (29 ± 9 vs 23.10 ± 10.18, respectively; p = 0.001), as were pseudarthrosis (28.47 ± 5.85 vs 24.41 ± 7.75, respectively; p = 0.001) and same-level recurrent stenosis (30.83 ± 5.28 vs 26.29 ± 4.10, respectively; p = 0.003). Independent of other factors—age, body mass index, symptom duration, smoking, comorbidities, severity of preoperative pain, and disability—increasing preoperative ZDS score was significantly associated with lower 2-year improvement in disability (ODI) after revision surgery in elderly patients with symptomatic ASD, pseudarthrosis, or recurrent stenosis.

Conclusions

The extent of preoperative depression is an independent predictor of less functional improvement following revision lumbar surgery in elderly patients with symptomatic ASD, pseudarthrosis, or recurrent stenosis. Timely diagnosis and treatment of depression and somatic anxiety in this cohort of patients may contribute to improvement in postoperative functional status.

Effectiveness of preemptive analgesia using a frequency rhythmic electrical modulation system in patients having instrumented fusion for lumbar stenosis

STUDY DESIGN

A randomized prospective study.

PURPOSE

To assess postoperative analgesic requirements after Phyback therapy preemptively in patients undergoing lumbar stabilization.

OVERVIEW OF LITERATURE

Frequency Rhythmic Electrical Modulation System is the latest method of preemptive analgesia.

METHODS

Forty patients were divided into two groups. Patients who were to receive tramadol were allocated to "group A" and those who were to receive Phyback therapy were allocated to "group B." In patients with a visual analog scale score of >4 or a verbal rating scale score of >2, 75 mg of diclofenac IM was administered. The amount of analgesic consumption, the bolus demand dosage, and the number of bolus doses administered were recorded. Patient satisfaction was evaluated using the visual analog patient satisfaction scale.

RESULTS

There were statistically significant differences in the visual analog scale and verbal rating scale scores in the fourth, sixth, 12th, and 24th hours. The number of bolus infusions was significantly lower in group B. The amount of analgesic consumption was higher in group A. There was a significant difference between the two groups in the number of bolus infusions and the total amount of analgesic consumption, and this comparison showed better results for group B.

CONCLUSIONS

Application of Phyback therapy reduced postoperative opioid consumption and analgesic demand, and it contributed to reducing patients' level of pain and increased patient satisfaction. Moreover, the application of preemptive Phyback therapy contributed to reducing preoperative pain which may have reduced patient anxiety.

Classification tree analysis of the factors influencing injury-related disability caused by the Wenchuan earthquake

OBJECTIVE

To identify the factors that influenced the risk of injury-related disability caused by the Wenchuan earthquake.

METHODS

A chi-squared automatic interaction detection (CHAID) classification tree analysis was used to retrospectively analyse clinical data from patients who underwent surgical treatment for earthquake-related injuries in the first 5 days after the earthquake. The CHAID classification tree explored the relationships between the development of disability and potential influencing factors including sex, age, time interval between injury and treatment, wound type, preoperative and postoperative haemoglobin levels, and operation time.

RESULTS

A total of 334 patients underwent surgery; of these, 113 (33.8%) were discharged with varying degrees of permanent disability. The CHAID classification tree showed that children (≤ 17 years old), a long time interval between injury and treatment, an open wound and a low preoperative haemoglobin level were significant risk factors for disability.

CONCLUSION

The results of this study can help to stratify patients according to their medical needs and to help allocate the available resources efficiently to ensure the best outcomes for injured patients during future earthquakes.

Who should undergo surgery for degenerative spondylolisthesis? Treatment effect predictors in SPORT

STUDY DESIGN

Combined prospective randomized controlled trial and observational cohort study of degenerative spondylolisthesis (DS) with an as-treated analysis.

OBJECTIVE

To determine modifiers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for DS using subgroup analysis.

SUMMARY OF BACKGROUND DATA

Spine Patient Outcomes Research Trial demonstrated a positive surgical TE for DS at the group level. However, individual characteristics may affect TE.

METHODS

Patients with DS were treated with either surgery (n = 395) or nonoperative care (n = 210) and were analyzed according to treatment received. Fifty-five baseline variables were used to define subgroups for calculating the time-weighted average TE for the Oswestry Disability Index during 4 years (TE = [INCREMENT] Oswestry Disability Index(surgery)- [INCREMENT] Oswestry Disability Index(nonoperative)). Variables with significant subgroup-by-treatment interactions (P< 0.05) were simultaneously entered into a multivariate model to select independent TE predictors.

RESULTS

All analyzed subgroups that included at least 50 patients improved significantly more with surgery than with nonoperative treatment (P< 0.05). Multivariate analyses demonstrated that age 67 years or less (TE -15.7 vs.-11.8 for age >67, P= 0.014); female sex (TE -15.6 vs.-11.2 for males, P= 0.01); the absence of stomach problems (TE -15.2 vs.-11.3 for those with stomach problems, P= 0.035); neurogenic claudication (TE -15.3 vs.-9.0 for those without claudication, P= 0.004); reflex asymmetry (TE -17.3 vs.-13.0 for those without asymmetry, P= 0.016); opioid use (TE -18.4 vs.-11.7 for those not using opioids, P< 0.001); not taking antidepressants (TE -14.5 vs.-5.4 for those on antidepressants, P= 0.014); dissatisfaction with symptoms (TE -14.5 vs.-8.3 for those satisfied or neutral, P= 0.039); and anticipating a high likelihood of improvement with surgery (TE -14.8 vs.-5.1 for anticipating a low likelihood of improvement with surgery, P= 0.019) were independently associated with greater TE.

CONCLUSION

Patients who met strict inclusion criteria improved more with surgery than with nonoperative treatment, regardless of other specific characteristics. However, TE varied significantly across certain subgroups.

LEVEL OF EVIDENCE

3.

Effect of smoking on the perioperative outcomes of patients who undergo elective spine surgery

STUDY DESIGN

Retrospective analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement database.

OBJECTIVE

We assessed whether preoperative cigarette smoking and smoking duration predicted adverse, early, perioperative outcomes in patients undergoing elective spine surgery.

SUMMARY OF BACKGROUND DATA

Prior studies have assessed the association of smoking and long-term outcomes for a number of spine surgery procedures, with conflicting findings. The association between smoking and 30-day outcomes for spine surgery is unknown.

METHODS

A total 14,500 adults, classified as current (N = 3914), prior (N = 2057), and never smokers. Using propensity scores, current and prior smokers were matched to never smokers. Logistic regression was used to predict adverse postoperative outcomes. The relationship between pack-years and adverse outcomes was tested. Sensitivity analyses were conducted limiting the study sample to patients who underwent spine fusion (N = 4663), and using patient subgroups by procedure.

RESULTS

In unadjusted analyses, prior smokers were significantly more likely to have prolonged hospitalization (1.2, 95% confidence interval [CI]: 1.1-1.3) and major complications (1.3, 95% CI: 1.1-1.6) compared with never smokers. No association was found between smoking status and adverse outcomes in adjusted, matched patient models. Current smokers with more than 60 pack-years were more likely to die within 30 days of surgery (3.0, 95% CI, 1.1-7.8), compared with never smokers. Sensitivity analyses confirmed these findings.

CONCLUSION

The large National Surgical Quality Improvement population was carefully matched for a wide range of baseline comorbidities, including 29 variables previously suggested to influence perioperative outcomes. Although previous studies conducted in subgroups of spine surgery patients have suggested a deleterious effect for smoking on long-term outcomes in patients undergoing spine surgery, our analysis did not find smoking to be associated with early (30 d) perioperative morbidity or mortality.

Laminarthrectomy as a surgical approach for decompressing the spinal canal: assessment of preoperative versus postoperative dural sac cross-sectional areal (DSCSA)

INTRODUCTION

Surgery for lumbar spinal stenosis (LSS) is today the most frequently performed procedure in the adult lumbar spine. Long-term benefit of surgery for LSS is well documented both in randomized and in non-randomized trials. In this paper, we present the results from laminarthrectomy as an alternative surgical approach, which have theoretical advantages over other approaches. In this study, we wanted to study the clinical and radiological results of laminarthrectomy. Dural sac cross-sectional areal (DSCSA) is an objective method to quantify the degree of central stenosis in the spinal canal, and was used to measure whether we were able to achieve an adequate decompression of the spinal canal with laminarthrectomy as a surgical approach.

MATERIALS AND METHODS

All patients operated on with this approach consecutively in the period 1 January 2008 to 31 March 2009 were included in the study. All perioperative complications were noted. Clinical results were measured by means of a questionnaire. The patients that agreed to attend the study had an MRI taken of the operated level. DSCSA before and after surgery of the actual level were measured by three observers. We then performed a correlation test between increase of area and clinical results. We also tested for inter- and intra-observer reability.

RESULTS

Fifty-six laminarthrectomy were performed. There were 17% complications, none of them were life-threatening or disabling. 46 patients attended the study and answered the questionnaire. Thirty-four patients (83%) reported clinical improvement, whereas six (13%) patients reported no improvement, and two (4%) patients reported that they were worse. Mean ODI was 23.0. Mean EQ-5D was 0.77. Mean VAS-score for back-pain was 3.1 and mean VAS-score for leg-pain was 2.8. Mean DSCSA were measured to 80 mm(2) before surgery and 161 mm(2) after surgery. That gave an increase of DSCSA of 81 mm(2) (101%). We found a significant positive correlation between increase of area and clinical results. We also found consistent inter- and intra-observer reability.

DISCUSSION

In this study, the clinical results of laminarthrectomy were good, and comparable with other reports for LSS. The rates of complications are also comparable with other reports in spinal surgery. A significant increase in the spinal canal diameter was achieved. Within the limitations a retrospective study gives, we conclude that laminarthrectomy seems to be a safe and effective surgical approach for significant decompressing the adult central spinal canal, and measurement of DSCSA, before and after surgery seems to be a good way to quantify the degree of decompression.

Who should have surgery for spinal stenosis? Treatment effect predictors in SPORT

STUDY DESIGN

Combined prospective randomized controlled trial and observational cohort study of spinal stenosis (SpS) with an as-treated analysis.

OBJECTIVE

To determine modifiers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for SpS using subgroup analysis.

SUMMARY OF BACKGROUND DATA

The Spine Patient Outcomes Research Trial demonstrated a positive surgical TE for SpS at the group level. However, individual characteristics may affect TE. No previous studies have evaluated TE modifiers in SpS.

METHODS

SpS patients were treated with either surgery (n = 419) or nonoperative care (n = 235) and were analyzed according to treatment received. Fifty-three baseline variables were used to define subgroups for calculating the time-weighted average TE for the Oswestry Disability Index (ODI) over 4 years (TE = ΔODIsurgery - ΔODInonoperative). Variables with significant subgroup × treatment interactions (P < 0.05) were simultaneously entered into a multivariate model to select independent TE predictors.

RESULTS

Other than smokers, all analyzed subgroups including at least 50 patients improved significantly more with surgery than with nonoperative treatment (P < 0.05). Multivariate analysis demonstrated: baseline ODI ≤ 56 (TE -15.0 vs. -4.4, ODI > 56, P < 0.001), not smoking (TE -11.7 vs. -1.6 smokers, P < 0.001), neuroforaminal stenosis (TE -14.2 vs. -8.7 no neuroforaminal stenosis, P = 0.002), predominant leg pain (TE -11.5 vs. -7.3 predominant back pain, P = 0.035), not lifting at work (TE -12.5 vs. -0.5 lifting at work, P = 0.017), and the presence of a neurological deficit (TE -13.3 vs. -7.2 no neurological deficit, P < 0.001) were associated with greater TE.

CONCLUSION

With the exception of smokers, patients who met strict inclusion criteria improved more with surgery than with nonoperative treatment, regardless of other specific characteristics. However, TE varied significantly across certain subgroups, and these data can be used to individualize shared decision making discussions about likely outcomes. Smoking cessation should be considered before surgery for SpS.

Does the duration of symptoms in patients with spinal stenosis and degenerative spondylolisthesis affect outcomes?: analysis of the Spine Outcomes Research Trial

STUDY DESIGN

Retrospective subgroup analysis of prospectively collected data according to treatment received.

OBJECTIVE

The purpose of this study is to determine whether the duration of symptoms affects outcomes after the treatment of spinal stenosis (SS) or degenerative spondylolisthesis (DS).

SUMMARY OF BACKGROUND DATA

The Spine Outcomes Research Trial (SPORT) study was designed to provide scientific evidence on the effectiveness of spinal surgery versus a variety of nonoperative treatments.

METHODS

An as-treated analysis was performed on the patients enrolled in SPORT for the treatment of SS or DS. A comparison was made between patients with SS with 12 or fewer months' (n = 405) and those with more than 12 months' (n = 227) duration of symptoms. A comparison was also made between patients with DS with 12 or fewer months' (n = 397) and those with more than 12 months' (n = 204) duration of symptoms. Baseline patient characteristics were documented. Primary and secondary outcomes were measured at baseline and at regular follow-up time intervals up to 4 years. The difference in improvement among patients whose surgical or nonsurgical treatment began less than or greater than 12 months after the onset of symptoms was measured. In addition, the difference in improvement with surgical versus nonsurgical treatment (treatment effect) was determined at each follow-up period for each group.

RESULTS

At final follow-up, there was significantly less improvement in primary outcome measures in SS patients with more than 12 months' symptom duration. Primary and secondary outcome measures within the DS group did not differ according to symptom duration. There were no statistically significant differences in the treatment effect of surgery in SS or DS patients.

CONCLUSION

Patients with SS with fewer than 12 months of symptoms experienced significantly better outcomes with surgical and nonsurgical treatment relative to those with symptom duration greater than 12 months. There was no difference in the outcome of patients with degenerative spondylolisthesis according to symptom duration.

Smokers show less improvement than nonsmokers two years after surgery for lumbar spinal stenosis: a study of 4555 patients from the Swedish spine register

STUDY DESIGN

A cohort study based on the Swedish Spine Register.

OBJECTIVE

To determine the relation between smoking status and disability after surgical treatment for lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

Smoking and nicotine have been shown to inhibit lumbar spinal fusion and promote disc degeneration. No association, however, has previously been found between smoking and outcome after surgery for lumbar spinal stenosis. A large prospective study is therefore needed.

METHODS

All patients with a completed 2-year follow-up in the Swedish Spine Register operated for central lumbar stenosis before October 1, 2006 were included. Logistic regression was used to assess the association between smoking status and outcomes.

RESULTS

Of 4555 patients enrolled, 758 (17%) were current smokers at the time of surgery. Smokers had an inferior health-related Quality of Life at baseline. Nevertheless, adjusted for differences in baseline characteristics, the odds ratio (OR) for a smoker to end up dissatisfied at the 2-year follow-up after surgery was 1.79 [95% confidence interval (CI) 1.51-2.12]. Smokers had more regular use of analgesics (OR 1.86; 95% CI 1.55-2.23). Walking ability was less likely to be significantly improved in smokers with an OR of 0.65 (95% CI 0.51-0.82). Smokers had inferior Quality of Life also after taking differences before surgery into account, either when measured with the Oswestry Disability Index (ODI; P < 0.001), EuroQol (P < 0.001) or Short Form (36) Health Survey (SF-36) BP and SF-36 PF (P < 0.001). The differences in results between smokers and nonsmokers were evident, irrespective of whether the decompression was done with or without spinal fusion.

CONCLUSION

Smoking is an important predictor for 2-year results after surgery for lumbar spinal stenosis. Smokers had less improvement after surgery than nonsmokers.

Predominant leg pain is associated with better surgical outcomes in degenerative spondylolisthesis and spinal stenosis: results from the Spine Patient Outcomes Research Trial (SPORT)

STUDY DESIGN

As-treated analysis of the Spine Patient Outcomes Research Trial.

OBJECTIVE

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 DS and SpS patients with predominant leg pain may have better surgical outcomes than patients with predominant low back pain (LBP).

METHODS

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 3 predominant pain location groups within each diagnostic category, and changes in surgical and nonoperative outcome scores were compared for 2 years. Longitudinal regression models including baseline covariates were used to control for confounders.

RESULTS

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 1 and 2 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. Conclusion. 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.

Stabilising effect of dynamic interspinous spacers in degenerative low-grade lumbar instability

The aim of the study was to investigate the stabilising effect of dynamic interspinous spacers (IS) in combination with interlaminar decompression in degenerative low-grade lumbar instability with lumbar spinal stenosis and to compare its clinical effect to patients with lumbar spinal stenosis in stable segments treated by interlaminar decompression only. Fifty consecutive patients with a minimum age of 60 years were scheduled for interlaminar decompression for clinically and radiologically confirmed lumbar spinal stenosis. Twenty-two of these patients (group DS) with concomitant degenerative low-grade lumbar instability up to 5 mm translational slip were treated by interlaminar decompression and additional dynamic IS implantation. The control group (D) with lumbar spinal stenosis in stable segments included 28 patients and underwent only interlaminar decompression. The mean follow-up was 46 months in group D and 44 months in group DS. A visual analogue scale (VAS), Oswestry Disability Index (ODI) and walking distance were evaluated pre- and postoperatively. The segmental instability was evaluated in flexion-extension X-rays. The implantation of an IS significantly reduced the lumbar instability on flexion-extension X-rays. At the time of follow-up walking distance, VAS and ODI showed a significant improvement in both groups, but no statistical significance between groups D and DS. Four patients each in groups D and DS had revision surgery during the period of evaluation. The stabilising effect of dynamic IS in combination with interlaminar decompression offers an opportunity for an effective treatment for degenerative low-grade lumbar instability with lumbar spinal stenosis.

Predictors of residual symptoms in lower extremities after decompression surgery on lumbar spinal stenosis

Leg pain/numbness and gait disturbance, two major symptoms in the lower extremities of lumbar spinal stenosis (LSS), are generally expected to be alleviated by decompression surgery. However, the paucity of information available to patients before surgery about specific predictors has resulted in some of them being dissatisfied with the surgical outcome when the major symptoms remain after the procedure. This prospective, observational study sought to identify the predictors of the outcome of a decompression surgery: modified fenestration with restorative spinoplasty. Of 109 consecutive LSS patients who underwent the decompression surgery, 89 (56 males and 33 females) completed the 2 year follow-up. Both leg pain/numbness and gait disturbance determined by the Japanese Orthopedic Association scoring system were significantly improved at 2 years after surgery compared to those preoperative, regardless of potential predictors including gender, preoperative presence of resting numbness in the leg, drop foot, cauda equina syndrome, degenerative spinal deformity or myelographic filling defect, or the number of decompressed levels. However, 27 (30.3%) and 13 (14.6%) patients showed residual leg pain/numbness and gait disturbance, respectively. Among the variables examined, the preoperative resting numbness was associated with residual leg pain/numbness and gait disturbance, and the preoperative drop foot was associated with residual gait disturbance, which was confirmed by logistic regression analysis after adjustment for age and gender. This is the first study to identify specific predictors for these two remaining major symptoms of LSS after decompression surgery, and consideration could be given to including this in the informed consent.

The influence of preoperative back pain on the outcome of lumbar decompression surgery

STUDY DESIGN

Prospective study with 12-month follow-up.

OBJECTIVE

To examine how the relative severity of low back pain (LBP) to leg/buttock pain (LP) influences the outcome of decompression surgery for spinal stenosis.

SUMMARY OF BACKGROUND DATA

Decompression surgery is a common treatment for lumbar spinal canal stenosis, with generally good outcome. However, concomitant LBP at presentation can make it difficult to decide whether decompression alone will result in a good overall outcome.

METHODS

The Spine Society of Europe Spine Tango system was used to acquire the data from 221 patients. Inclusion criteria were lumbar degenerative spinal stenosis, first-time surgery, maximum 3 affected levels, and decompression as the only procedure. Before and 12 months after surgery, patients completed the multidimensional Core Outcome Measures Index (COMI; includes 0-10 LP and LBP scales); at 12 months, global outcome was rated on a Likert-scale and dichotomized into "good" and "poor" groups.

RESULTS

There was a low but significant positive correlation between baseline LP-minus-LBP scores and both improvement in the multidimensional COMI score after 12 months (r = 0.21, P = 0.003) and the score on the 12-month global outcome scale (r = 0.19, P = 0.007). In the good outcome group, mean baseline LP was 2.3 (+/-3.7) points higher than LBP; in the poor group, the corresponding value was 0.8 (+/-3.4) (P = 0.01 between groups). In multivariate regression analyses (controlling for age, gender, comorbidity), baseline LBP intensity was the most significant predictor of the 12-month COMI score, and preoperative LP-minus-LBP score of the global outcome (each P < 0.05).

CONCLUSION

Overall, greater back pain relative to LP at baseline was associated with a significantly worse outcome after decompression. This finding seems intuitive, but has rarely been quantified in the many predictor studies conducted to date. Consideration of relative LBP and LP scores may assist in clinical decision-making and in establishing realistic patient expectations.

Spinal canal size and clinical symptoms among persons diagnosed with lumbar spinal stenosis

OBJECTIVE

Clinical symptoms associated with lumbar spinal stenosis (LSS) are believed to be due to neurogenic claudication caused by narrowing of the central and lateral spinal canals. However, there is a paucity of published data on these relationships. The purpose of the present study was to examine the relationship between clinical symptoms associated with LSS and osseous anterior-posterior (AP) spinal canal diameter as measured on axial magnetic resonance imaging.

DESIGN

Cross-sectional study conducted at a University Spine Program. Fifty persons with a clinical diagnosis of LSS were administered measures of clinical pain and perceived function. Walking distance in the laboratory and community was also assessed. Participants also underwent magnetic resonance imaging of the spine.

RESULTS

Using recommended upper limits from the literature, patients with smaller canals reported greater perceived disability, but no other group differences emerged. In the entire sample, AP spinal canal diameter was not significantly associated with any of the clinical symptom measures examined. Body mass index was found to be significantly related to walking distance, but not perceived function or pain.

CONCLUSIONS

AP spinal canal diameter is not predictive of clinical symptoms associated with LSS. The findings also suggest that body mass may play a significant role in functional limitations observed in this population.

Validity of the new Backache Index (BAI) in patients with low back pain

BACKGROUND CONTEXT

The Backache Index (BAI) is applied to patients with low back pain (LBP) in order to help therapists, doctors, and surgeons perform physical examinations easily. It is carried out within a short space of time (<2 min) without using inclinometric instruments.

PURPOSE

To explore the reliability, validity, and responsiveness of this new Backache Index in patients with LBP, which can fulfil the existing need for a reliable routine examination in the clinical environment.

STUDY DESIGN/SETTING

Patients with LBP filled in disability questionnaires; pain rating scales and physical impairment tests were completed in function of construct validity and correlation studies. A subgroup was evaluated for interobserver and test-retest reliability, and a second group was reassessed after two active treatment sessions to verify the responsiveness compared with other examined variables.

PATIENT SAMPLE

In total, 75 patients with subacute LBP (3-12 weeks) participated in a randomized controlled study.

OUTCOME MEASURES

The validity of the BAI was explored through a correlation with the standard Oswestry LBP Disability Index (ODI), the McGill LBP Questionnaire Index (MPQ), and the Visual Analogue Scale (VAS).

METHODS

The BAI consisted of a scoring system that includes pain factors and stiffness estimation at the end of a series of five different lumbar movements of a patient standing in an erect position.

RESULTS

The correlations between the separate outcomes and the BAI ranged from 0.61 to 0.76 (p<.001). The interobserver reliability between two experienced observers for the five outcome scores was good (intraclass correlation coefficient [ICC]>0.86) and even perfect for the BAI (ICC=0.96). A BAI change of one unit is able to exclude a measurement error. A significantly good correlation (p<.001) was found between the BAI at baseline, the ODI (R=0.62), and the total degree of pain rating index (MPQ-PRI-T) (R=0.57), a moderate correlation with the total number of chosen adjectives from the whole list of adjectives (MPQ-NWC-T) (R=0.48), and the VAS (R=0.47), but a lower correlation was found with the MPQ-Quality of life index (R=0.43). The effect size and discriminative ability of the measures were explored after two treatment sessions of deep transverse friction myotherapy by means of study of the receiver operating characteristics curve (ROC) and the greatest area under the curve (AUC). The greatest level of distinction was found for the MPQ-PRI-T and the BAI (AUC>0.93), followed by the ODI (AUC=0.92). A lower level of distinction was found for the MPQ-NWC-T and the VAS (AUC>0.82).

CONCLUSIONS

The BAI appears to be a reliable and valid assessment of overall restricted spinal movements in case of LBP and discriminates between successful and unsuccessful treatment outcome.

Preoperative predictors for postoperative clinical outcome in lumbar spinal stenosis: systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To define preoperative factors predicting clinical outcome after lumbar spinal stenosis (LSS) surgery.

SUMMARY OF BACKGROUND DATA

LSS is the most common reason requiring lumbar spine surgery in adults older than 65 years. There are no published systematic reviews on this topic.

METHODS

A literature search was done until April 30, 2005. Included were randomized controlled or controlled trials or prospective studies dealing with operated LSS. The preoperative predictors had to be presented. Included articles were assessed as high-quality (HQ) and low-quality studies. The predictors in HQ studies were considered as the main results.

RESULTS

A total of 21 articles were included. Depression and walking capacity were predictors according to 2 HQ studies. Predictors reported in 1 HQ study were cardiovascular/overall comorbidity, disorder influencing walking ability, self-rated health, income, severity of central stenosis, and scoliosis.

CONCLUSION

Depression, cardiovascular comorbidity, disorder influencing walking ability, and scoliosis predicted poorer subjective outcome. Better walking ability, self-rated health, higher income, less overall comorbidity, and pronounced central stenosis predicted better subjective outcome. Male gender and younger age predicted better postoperative walking ability. The predictive value may be outcome specific; thus, the use of all relevant outcome measures is recommended when studying predictors of LSS.

Five-year outcomes of surgical treatment for degenerative lumbar spinal stenosis: a prospective observational study of symptom severity at standard intervals after surgery

STUDY DESIGN

A prospective observational study of patients undergoing surgery for degenerative lumbar spinal stenosis.

OBJECTIVE

To determine whether the long-term outcomes differ as a function of age and gender.

SUMMARY OF BACKGROUND DATA

The long-term results of surgery for lumbar spinal stenosis are not well understood, and the patient characteristics that predispose patients to worse outcomes are unknown.

METHODS

Seventy patients who underwent decompressive laminotomy with or without arthrodesis for degenerative lumbar spinal stenosis were prospectively studied at standard intervals after surgery with respect to symptom severity rated on a visual analog scale (VAS).

RESULTS

The VAS scores for younger patients improved steadily for 3 or 6 months, after which the improvement was maintained until 60 months. The VAS scores for older patients showed a similar time course until 36 months, after which the VAS scores were worse compared with those for younger patients. The VAS scores for females were worse than those for males, in three symptoms queried, at one or more of the evaluation time points.

CONCLUSION

In patients undergoing surgery for degenerative lumbar spinal stenosis, older age predicts a greater risk of late recurrence of symptoms, and women have higher VAS scores than men after surgery.

Discriminative validity and responsiveness of the Oswestry Disability Index among Japanese outpatients with lumbar conditions

The Oswestry Disability Index (ODI) is one of the most used assessment scales for patients with spine conditions, and translations into several languages have already been available. However, the scale's discriminative validity and responsiveness to the clinical change was somewhat understudied in these translated versions of the ODI. In this study, we independently developed a Japanese version of the ODI, and tested its discriminative and responsive performances among outpatients with various spinal conditions. We recruited 167 outpatients from seven participating clinics, and concurrently measured the translated ODI and MOS Short Form 36 (SF36) as a reference scale. We also obtained from medical records clinical information such as diagnoses, the past history of surgery, and existence of subjective symptoms and clinical signs. For testing discriminative validity, scores were compared by the number of symptoms and signs, with the trend test. Receiver operating characteristics (ROC) analysis was also conducted to compare ODI and SF36 in their performance to discriminate the existence of signs/symptoms, by chi-square test on the area under ROC curve (AUC). For 35 patients (17 clinically stable, 18 undergoing surgery and clinically significantly changed), the two scales were repeatedly administered after 3-6 months to compare responsiveness by using ROC analysis. The translated ODI and the SF36 Physical Function (PF) subscale showed a significant trend increase as the numbers of symptoms/signs increased. They also showed comparable performance in discriminating the existence of signs/symptoms (AUC=0.70-0.76 for ODI, 0.69-0.70 for SF36 PF, P=0.15-0.81), and clinical status change over time (AUC=0.82 for ODI, 0.72 for SF36 PF, P=0.31). Our results showed that the translated Japanese ODI showed fair discriminative validity and responsiveness as the original English scale showed.

Patient-based outcomes for the operative treatment of degenerative lumbar spinal stenosis

STUDY DESIGN

A retrospective surgical case series was conducted using a condition-specific, patient-based outcomes assessment.

OBJECTIVE

The goal of this study was to describe the outcome predictors of decompressive surgery for degenerative lumbar spinal stenosis (DLSS).

SUMMARY OF BACKGROUND DATA

Surgical decompression is the recommended treatment for patients with moderate to severe DLSS. Previous studies have reported that factors such as the number of operated levels and patient health status are predictors of surgical outcomes.

METHODS

This study analyzed the success rates of 58 DLSS patients treated with decompressive surgery. Outcomes were measured with the Zurich Claudication Questionnaire (ZCQ) completed pre-operatively and at least 12 months post-operatively (range 12-54 months). The ZCQ includes three distinct domains that involve symptom severity, physical function, and patient satisfaction. Variables such as age, sex, pre-operative symptom severity, and arthrodesis were analyzed as predictors of success.

RESULTS

The study group included 21 males and 37 females, and the mean age of all patients was 66 years (range 41-80 years). Overall, 63.8% of the patients had significant clinical improvement in Symptom Severity, 55.2% had significant clinical improvement in Physical Function, and 58.6% of the patients were at least somewhat satisfied; 63.8% (37/58) of the patients were considered to be clinically successful. Patients with more severe pre-operative symptoms and more physical function restrictions had better success results than those patients with milder symptoms and less restrictive physical function. Also, patients who were followed for less than 24 months had better success than those followed for more than 24 months. There was no significant difference in the clinical success rates of (1) patients who were fused and those not fused, (2) males and females, (3) patients aged less than 65 years and those greater than 65 years, and (4) patients who were treated at one or two levels and those treated at three or four levels.

CONCLUSION

The results of this retrospective study indicate that operative decompression of the lumbar spine offers significant improvement for patients with DLSS. Although not all comparisons were statistically significant, there was a trend for DLLS patients aged less than 65 years with more severe pre-operative symptoms and physical function disturbances treated at one or two levels with a laminectomy and fusion to have the best outcomes.

Predictors of surgical outcome and their assessment

The relatively high rate of failed back surgery has prompted the search for "risk factors" to predict the result of spinal surgery in a given individual. However, the literature reveals few unequivocal predictors and they often explain a relatively low proportion of variance in outcome. This suggests that we have a long way to go before being able to rest easily, having refused someone surgery on the basis of unfavourable baseline characteristics. The best recommendation is to ensure, firstly, that the indication for surgery is absolutely clear-cut (i.e. that surgically remediable pathology exists) and then to consider the various factors that may influence the "typical" outcome. Consistent risk factors for a poor outcome regarding return-to-work include long-term sick leave/receipt of disability benefit. Hence, every effort should be made to keep the individual in the workforce, despite the ongoing symptoms and plans for surgery. In patients with a particularly heavy job, consultation with occupational physicians might later ease the patient's way back into the workplace. Patients with degenerative disorders and/or comorbidity should be counselled that few of them will have complete/lasting pain relief or a complete return to pre-morbid function. Patients with a high level of distress may benefit from psychological treatment, before and/or accompanying the surgical treatment. The opportunity (time), encouragement (education and positive messages), and resources (referral to appropriate support services) to modify risk factors that are indeed modifiable should be offered, and realistic expectations should be discussed with the patient before the decision to operate is made.

Gender differences as an influence on patients' satisfaction rates in spinal surgery of elderly patients

There is an increased rate of lumbar spinal operations in elderly patients due to lumbar spinal stenosis. Many factors affect the decision of the patient and surgeon to perform the operation, among which are the age of the patient, comorbidities and willingness to undergo surgery. However, the gender of the patient is rarely taken into consideration as a factor for performing the operation. The satisfaction of the patient is an important factor to assess the operative success retrospectively. Therefore, we assessed the differences caused by gender on the satisfaction of elderly patients following lumbar spinal surgery. Three hundred and sixty-seven elderly patients (>65 years) treated in our institution from 1990 to 2000 for lumbar spinal stenosis and who underwent laminectomy without fusion filled in a questionnaire prior to operation regarding their gender, demographic status, comorbidities, activities of daily living (ADL) using the Barthel index, and pain according to visual analogue scale. At follow-up, a telephone interview on 298 patients was structured and included the same pre-operative questions and additional questions regarding the satisfaction rate from surgery. Two hundred and ninety-eight patients responded to our telephone interview with a minimum follow-up of 1 year (mean: 64 months). After surgery, both women and men showed improvement in their ADL, and reduction in pain perception. The number of very satisfied patients was similar in both groups, but women were significantly more dissatisfied with the operation. The surgical parameters, including complications, did not differ between the groups. Gender differences were found to influence the satisfaction rate of lumbar spinal stenosis surgery. Women tend to have less satisfactory results than men. The reasons for that are probably multifactorial and are not related to the surgery per se.

The Michel Benoist and Robert Mulholland yearly European Spine Journal Review. A survey of the "surgical and research" articles in the European Spine Journal, 2004

The Deputy Editor has explained in his editorial the reason for this review. I found it a challenging but very rewarding project. The overall quality of papers was so good that it was very difficult to select the necessarily few which space would allow me to review. Inevitably I am influenced by my particular interests, and hence very many excellent papers will not be discussed; failure to discuss a paper is not a reflection on its quality or importance. Criticisms of papers again reflect my own prejudices.