The Influence of Titanium-coated Poryetheretherketone Cages in Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation.

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) with cortical bone trajectory (CBT) screw fixation (CBT-PLIF) shows potential for reducing adjacent segmental disease. Previously, our investigations revealed a relatively lower fusion rate with the use of carbon fiber-reinforced polyetheretherketone (CP) cages in CBT-PLIF compared with traditional pedicle screw fixation (PS-PLIF) using CP cages. This study aims to evaluate whether the implementation of titanium-coated polyetheretherketone (TP) cages can enhance fusion outcomes in CBT-PLIF. METHODS: A retrospective analysis was conducted on 68 consecutive patients who underwent CBT-PLIF with TP cages (TP group) and 89 patients who underwent CBT-PLIF with CP cages (CP group). Fusion status was assessed using computed tomography at 1 year postoperatively and dynamic plain radiographs at 2 years postoperatively. RESULTS: No statistically significant differences in fusion rates were observed at 1 and 2 years postoperatively between the TP group (86.8% and 89.7%, respectively) and the CP group (77.5% and 88.8%, respectively). Notably, the CP group exhibited a significant improvement in fusion rate from 1 to 2 years postoperatively (P = 0.002), while no significant improvement was observed in the TP group. CONCLUSIONS: Examination of temporal changes in fusion rates reveals that only the TP group achieved a peak fusion rate 1 year postoperatively. This implies that TP cages may enhance the fusion process even after CBT-PLIF. Nevertheless, the definitive efficacy of TP cages for CBT-PLIF remains uncertain in the context of overall fusion rates.

Relief of Low Back Pain After Posterior Decompression for Lumbar Spinal Stenosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to confirm that decompression for lumbar spinal stenosis (LSS) relieves low back pain (LBP) as adequately as it relieves leg pain and to identify predictors for inadequate LBP relief. SUMMARY OF BACKGROUND DATA: Although decompression for LSS is generally thought to yield worse results for LBP than for leg pain, some studies have reported similar improvements in pain scores between LBP and leg pain. To treat LBP or take measures to prevent inadequate LBP relief, reliable predictors for LBP relief should be identified. METHODS: We retrospectively reviewed 175 patients who underwent posterior element-preserving decompression and evaluated the relief of LBP and leg pain using numeric rating scales (NRSs). Associations between demographic, clinical, or imaging parameters and LBP relief at 1 and 4 years were analyzed by stepwise linear regression analyses. The imaging parameters included Modic change type 1, disc degeneration, foraminal stenosis, vertebral slipping (within Grade 1), scoliosis (<15°) and lordosis. RESULTS: The mean improvements in LBP and leg pain NRS scores from baseline were 5.22 and 4.70 points (P = 0.064, paired t test) at 1 year and 5.12 and 4.62 points (P = 0.068) at 4 years, respectively. Poor LBP scores at 4 years were significantly associated with long-lasting LBP (beta = 0.31, P < 0.0001) and moderate or severe arm symptoms with cervical spinal cord compression or intramedullary hyperintense signal on T2-weighted MRI (beta = 0.22, P = 0.0014). The imaging parameters of the lumbar spine failed to show clear associations with poor LBP scores at 4 years, although Modic change type 1 showed a significant association with poor LBP scores at 1 year (beta = 0.28, P < 0.0001). CONCLUSION: Posterior decompression relieves LBP as well as leg pain. Long-lasting LBP and concurrent symptomatic cervical myelopathy are important predictors for inadequate LBP relief. There were no reliable imaging parameters predictive of inadequate LBP relief.Level of Evidence: 4.

An intraspinal extradural lipoma with spinal epidural lipomatosis: A case report and a review of literature.

BACKGROUND: Intraspinal extradural lipomas are very rare and should be differentiated from spinal epidural lipomatosis (SEL) and/or angiolipomas. CASE DESCRIPTION: A 76-year-old male presented with left lower extremity radiculopathy. The magnetic resonance imaging (MRI) revealed hyperplasia of epidural fat at the L2-3 and L3-4 levels accompanied by a lipomatous L4-5 mass. Following resection of this mass and hyperplastic epidural fat, the histological examination was consistent with an intraspinal extradural lipoma and SEL. CONCLUSION: This case indicates that asymmetrical compression of the dural sac may be attributed to an intraspinal extradural lipoma vs. just SEL and/or an angiolipoma.

Intradural Disk Herniation Mimicking a Spinal Tumor: Radiologic Imaging, Pathogenesis, and Operative Management.

Intradural disk herniation (IDH) is a rare condition, occurring more often at the L4-5 level. We examined a case of an IDH at the L1-2 level mimicking an intradural spinal tumor. A 71-year-old woman with a long history of backache and pain radiating down the left leg was admitted to our hospital with the worsening of these symptoms. Magnetic resonance imaging and computed tomographic myelography demonstrated an intradural mass at the L1-2 level. Given the radiologic findings and the location of the mass, the preoperative differential diagnosis centered on intradural spinal tumors. Dural incision was performed using a surgical microscope to resect the mass. Contrary to our expectation, the diagnosis made during the surgery was IDH. Despite advances in imaging techniques, IDH could not be definitively diagnosed preoperatively. The pathogenesis of IDH remains unclear. In our patient, the ventral dural defect was smooth and round, and the dural tissue around the defect was thickened. These intraoperative findings suggested that the patient's IDH resulted not from an acute new event but from a chronic process. We recommend dural incision using a surgical microscope for treating IDH because it provides a clear visual field.

Spinopelvic sagittal imbalance as a risk factor for adjacent-segment disease after single-segment posterior lumbar interbody fusion.

Objective: The importance of spinopelvic balance and its implications for clinical outcomes after spinal arthrodesis has been reported in recent studies. However, little is known about the relationship between adjacent-segment disease (ASD) after lumbar arthrodesis and spinopelvic alignment. The purpose of this study was to clarify the relationship between spinopelvic radiographic parameters and symptomatic ASD after L4­5 single-level posterior lumbar interbody fusion (PLIF). Methods: This was a retrospective 1:5 matched case-control study. Twenty patients who had undergone revision surgery for symptomatic ASD after L4­5 PLIF and had standing radiographs of the whole spine before primary and revision surgeries were enrolled from 2005 to 2012. As a control group, 100 age-, sex-, and pathology-matched patients who had undergone L4­5 PLIF during the same period, had no signs of symptomatic ASD for more than 3 years, and had whole-spine radiographs at preoperation and last follow-up were selected. Mean age at the time of primary surgery was 68.9 years in the ASD group and 66.7 years in the control group. Several radiographic spinopelvic parameters were measured as follows: sagittal vertical axis (SVA), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and segmental lordosis at L4­5 (SL) in the sagittal view, and C7­central sacral vertical line (C7-CSVL) in the coronal view. Radiological parameters were compared between the groups. Results: No significant change was found between pre- and postoperative radiographic parameters in each group. In terms of preoperative radiographic parameters, the ASD group had significantly lower LL (40.7° vs 47.2°, p < 0.01) and significantly higher PT (27° vs 22.9°, p < 0.05) than the control group. SVA ≥ 50 mm was observed in 10 of 20 patients (50%) in the ASD group and in 21 of 100 patients (21%, p < 0.01) in the control group. PI-LL ≥ 10° was noted in 15 of 20 patients (75%) in the ASD group and in 40 of 100 patients (40%, p < 0.01) in the control group on preoperative radiographs. Postoperatively, the ASD group had significantly lower TK (22.5° vs 30.9°, p < 0.01) and lower LL (39.3° vs 48.1°, p < 0.05) than the control group had. PI-LL ≥ 10° was seen in 15 of 20 patients (75%) in the ASD group and in 43 of 100 patients (43%, p < 0.01) in the control group. Conclusions: Preoperative global sagittal imbalance (SVA > 50 mm and higher PT), pre- and postoperative lower LL, and PI-LL mismatch were significantly associated with ASD. Therefore, even with a single-level PLIF, appropriate SL and LL should be obtained at surgery to improve spinopelvic sagittal imbalance. The results also suggest that the achievement of the appropriate LL and PI-LL prevents ASD after L4­5 PLIF.

High-dose tranexamic acid reduces intraoperative and postoperative blood loss in posterior lumbar interbody fusion.

OBJECTIVE Tranexamic acid (TXA), a synthetic antifibrinolytic drug, has been reported to reduce blood loss in orthopedic surgery, but there have been few reports of its use in spine surgery. Previous studies included limitations in terms of different TXA dose regimens, different levels and numbers of fused segments, and different surgical techniques. Therefore, the authors decided to strictly limit TXA dose regimens, surgical techniques, and fused segments in this study. There have been no reports of using TXA for prevention of intraoperative and postoperative blood loss in posterior lumbar interbody fusion (PLIF). The purpose of the study was to evaluate the efficacy of high-dose TXA in reducing blood loss and its safety during single-level PLIF. METHODS The study was a nonrandomized, case-controlled trial. Sixty consecutive patients underwent single-level PLIF at a single institution. The first 30 patients did not receive TXA. The next 30 patients received 2000 mg of intravenous TXA 15 minutes before the skin incision was performed and received the same dose again 16 hours after the surgery. Intra- and postoperative blood loss was compared between the groups. RESULTS There were no statistically significant differences in preoperative parameters of age, sex, body mass index, preoperative diagnosis, or operating time. The TXA group experienced significantly less intraoperative blood loss (mean 253 ml) compared with the control group (mean 415 ml; p < 0.01). The TXA group also had significantly less postoperative blood loss over 40 hours (mean 321 ml) compared with the control group (mean 668 ml; p < 0.01). Total blood loss in the TXA group (mean 574 ml) was significantly lower than in the control group (mean 1080 ml; p < 0.01). From 2 hours to 40 hours, postoperative blood loss in the TXA group was consistently significantly lower. There were no perioperative complications, including thromboembolic events. CONCLUSIONS High-dose TXA significantly reduced both intra- and postoperative blood loss without causing any complications during or after single-level PLIF.

Patient-Based Surgical Outcomes of Posterior Lumbar Interbody Fusion: Patient Satisfaction Analysis.

STUDY DESIGN: A retrospective study. OBJECTIVE: The purpose of this study was to investigate: (1) patient-based surgical outcomes of posterior lumbar interbody fusion (PLIF); (2) correlations between patient-based surgical outcomes and surgeon-based surgical outcomes; (3) factors associated with patient satisfaction. SUMMARY OF BACKGROUND DATA: There have been no reports of patient-based surgical outcomes of PLIF for lumbar spondylolisthesis. METHODS: Patients who underwent PLIF for L4 degenerative spondylolisthesis between 2006 and 2009 were reviewed (n = 121). Surgical outcomes were assessed 5 years after primary surgery using a questionnaire, a numerical rating scale (NRS) of pain, the 36-Item Short Form Health Survey (SF-36), the Japanese Orthopedic Association score (JOA score), and the recovery rate. The original questionnaire consisted of 5 categories, with scoring out of 100 points for surgery, satisfaction, improvement, recommendation to others, and willingness to undergo repeat surgery. Patient-based outcomes were divided into 3 groups according to the questionnaire responses as positive, intermediate, and negative and were compared with the JOA scores. RESULTS: A total of 103 patients responded, for a response rate of 85%. The average patient-evaluated score for surgery was 82 points. The positive response rate in each category was 78% for satisfaction, 88% for improvement, 74% for recommendation, and 71% for repeat. The average pre- and postoperative JOA scores were 11.2 and 23.2, respectively. The average recovery rate was 68.5%. There were significant correlations between patient-based surgical outcomes and the JOA score. Furthermore, there were significant correlations between patient-based surgical outcomes and the NRS and physical component scores of the SF-36. Postoperative permanent motor loss was a major factor related to a negative response. CONCLUSION: The patient-evaluated score for surgery was 82 points. More than 70% of patients gave positive responses in all sections of the questionnaire. There were significant correlations between patient-based and surgeon-based surgical outcomes. LEVEL OF EVIDENCE: 2.

Validity of the Japanese Orthopaedic Association scoring system based on patient-reported improvement after posterior lumbar interbody fusion.

BACKGROUND CONTEXT: The Japanese Orthopaedic Association (JOA) scoring system is a physician-based outcome that has been used to evaluate treatment effectiveness after lumbar surgery. However, patient-centered evaluation becomes increasingly important. There is no study that has examined the relationship between the JOA scoring system and patients' self-reported improvement. PURPOSE: The purpose of the present study was to validate the JOA scoring system for assessment of patient-reported improvement after lumbar surgery. STUDY DESIGN: This is a retrospective review of prospectively collected data. PATIENT SAMPLE: The patient sample included 273 mail-in responders of the 466 consecutive patients who underwent posterior lumbar interbody fusion for spondylolisthesis between 1996 and 2008 in a single hospital. OUTCOME MEASURES: The outcome measures were the JOA scoring system and patients' self-reported improvement. METHODS: Two hundred seventy three patients were divided into five anchoring groups based on self-reported improvement from "Much better" to "Much worse." Outcomes (ie, recovery rate, amount of change from preoperative condition, and postoperative score) based on the JOA scoring system were compared among groups. Using the patient's self-reported improvement scale as an anchor, the association among each of the outcomes was examined. The cutoff point and the area under the curve (AUC) that differentiated "Improved" from "Neither improved nor worse" was calculated using receiver operating characteristic (ROC) curve analysis. RESULTS: The recovery rate and postoperative score were significantly different in 9 of 10 pairs of anchoring groups. The amount of change was significantly different in six pairs. Spearman correlation coefficient for the 5-point scale anchors of patients' self-reported improvement was 0.20 (p=.001) for the baseline score, 0.31 (p<.001) for the amount of change, 0.55 (p<.001) for the recovery rate, and 0.56 (p<.001) for the postoperative score. According to ROC analysis, the best cutoff points and AUCs were 13 points and 0.69, respectively, for the amount of change, 67% and 0.73, respectively, for recovery rate, and 23 points and 0.72, respectively, for postoperative score. CONCLUSIONS: The JOA scoring system is a valid method for assessment of patients' self-reported improvement. Patients' self-reported improvement is more likely to be associated with the final condition, such as postoperative score or recovery rate, rather than the change from the preoperative condition.

Neurogenic Shock Immediately following Posterior Lumbar Interbody Fusion: Report of Two Cases.

Study Design Case report. Objective To present two cases of neurogenic shock that occurred immediately following posterior lumbar interbody fusion (PLIF) and that appeared to have been caused by the vasovagal reflex after dural injury and incarceration of the cauda equina. Case Report We present two cases of neurogenic shock that occurred immediately following PLIF. One patient had bradycardia, and the other developed cardiac arrest just after closing the surgical incision and opening the drainage tube. Cardiopulmonary resuscitation was performed immediately, and the patients recovered successfully, but they showed severe motor loss after awakening. The results of laboratory data, chest X-ray, electrocardiogram, computed tomography, and echocardiography ruled out pulmonary embolism, hemorrhagic shock, and cardiogenic shock. Although the reasons for the postoperative shock were obscure, reoperation was performed to explore the cause of paralysis. At reoperation, a cerebrospinal fluid collection and the incarceration of multiple cauda equina rootlets through a small dural tear were observed. The incarcerated cauda equina rootlets were reduced, and the dural defect was closed. In both cases, the reoperation was uneventful. From the intraoperative findings at reoperation, it was thought that the pathology was neurogenic shock via the vasovagal reflex. Conclusion Incarceration of multiple cauda equina rootlets following the accidental dural tear by suction drainage caused a sudden decrease of cerebrospinal fluid pressure and traction of the cauda equina, which may have led to the vasovagal reflex.

Age-related surgical outcomes of laminoplasty for cervical spondylotic myelopathy.

Study Design Retrospective clinical study. Objective To investigate the age-related surgical outcomes of laminoplasty. Methods One hundred patients who underwent an en bloc laminoplasty for cervical spondylotic myelopathy from 2004 to 2008 and were followed for at least 1 year were included in this study. The clinical outcomes were assessed with the Japanese Orthopaedic Association (JOA) score. Acquired points (postoperative JOA score minus preoperative JOA score) were also calculated. To investigate the age-related effect for laminoplasty, two analyses were conducted: (1) the correlation between age and clinical outcome; and (2) the clinical outcomes by decade. Patients were divided into four groups according to their age at the time of operation as follows: group 50s, 50 to 59 years old; group 60s, 60 to 69 years; group 70s, 70 to 79 years; and group 80s, 80 to 89 years. The pre- and postoperative JOA scores, acquired points, preoperative comorbidities, and postoperative complications were then compared among the groups. Results Significant correlations were detected between age and JOA scores at the preoperative (p = 0.03), postoperative maximum (p < 0.0001), and final assessments (p < 0.0001). An age-related decline of JOA scores was observed over all periods. The analysis by decades showed the same results. On the other hand, the significant differences were not found for acquired points over all periods by either method. The preoperative comorbidities of hypertension and diabetes mellitus increased with age. Delirium was more common postoperatively in elderly patients. Conclusions Although an age-related decline of JOA scores was found over all periods, there were no severe sequelae and no differences in the acquired points that were age-related.

Posterior lumbar interbody fusion with total facetectomy for low-dysplastic isthmic spondylolisthesis: effects of slip reduction on surgical outcomes: clinical article.

OBJECT: The management of isthmic spondylolisthesis remains controversial, especially with respect to reduction. There have been no reports regarding appropriate slip reduction. The purpose of this study was to investigate the following issues: (1) surgical outcomes of posterior lumbar interbody fusion (PLIF) with total facetectomy for low-dysplastic isthmic spondylolisthesis, including postoperative complications; (2) effects of slip reduction on surgical outcomes; and (3) appropriate slip reduction. METHODS: A total of 106 patients who underwent PLIF with total facetectomy for low-dysplastic isthmic spondylolisthesis and who were followed for at least 2 years were reviewed. The average follow-up period was 8 years. Surgical outcomes, including the scores assessed using the Japanese Orthopaedic Association scoring system, the recovery rate, and postoperative complications were investigated. As for radiographic evaluations, pre- and postoperative slip and disc height, instrumentation failure, and fusion status were also examined. RESULTS: The pre- and postoperative average Japanese Orthopaedic Association scores were 14 (range 3-25) and 25 (range 11-29) points, respectively. The average recovery rate was 73% (range 0%-100%). The average pre- and postoperative slip was 24% and 10%, respectively. A significant correlation between postoperative slip and clinical outcomes was found; clinical outcomes were better in proportion to slip reduction. Although no statistical difference was detected in clinical outcomes between postoperative slip of less than 10% and from 10% to 20%, patients with postoperative slip of more than 20% showed significantly worse clinical outcomes. Postoperative complications included neurological deficits in 7 patients (transient motor loss in 6 and permanent motor loss in 1), instrumentation failures in 7, adjacent-segment degeneration in 5, and nonunion in 4. Instrumentation failures occurred significantly more often in patients with more slip reduction, although slip reduction did not affect the other postoperative complications. All patients with instrumentation failure showed postoperative slip reduction within 10%. CONCLUSIONS: The use of PLIF with total facetectomy for low-dysplastic isthmic spondylolisthesis appears to produce satisfactory clinical outcomes, with an average of 73% recovery rate and few postoperative complications. Although clinical outcomes were better in proportion to slip reduction, excessive reduction caused instrumentation failure, and patients with less reduction demonstrated worse clinical outcomes. Appropriate reduction resulted in a postoperative slip ranging from 10% to 20%.

Repeated adjacent-segment degeneration after posterior lumbar interbody fusion.

One of the most important sequelae affecting long-term results is adjacent-segment degeneration (ASD) after posterior lumbar interbody fusion (PLIF). Although several reports have described the incidence rate, there have been no reports of repeated ASD. The purpose of this report was to describe 1 case of repeated ASD after PLIF. A 62-year-old woman with L-4 degenerative spondylolisthesis underwent PLIF at L4-5. At the second operation, L3-4 PLIF was performed for L-3 degenerative spondylolisthesis 6 years after the primary operation. At the third operation, L2-3 PLIF was performed for L-2 degenerative spondylolisthesis 1.5 years after the primary operation. Vertebral collapse of L-1 was detected 1 year after the third operation, and the collapse had progressed. At the fourth operation, 3 years after the third operation, vertebral column resection of L-1 and replacement of titanium mesh cages with pedicle screw fixation between T-4 and L-5 was performed. Although the patient's symptoms resolved after each operation, the time between surgeries shortened. The sacral slope decreased gradually although each PLIF achieved local lordosis at the fused segment.

Surgical outcomes of posterior thoracic interbody fusion for thoracic disc herniations.

INTRODUCTION: Surgical strategy for thoracic disc herniation (TDH) remains controversial. We have performed posterior thoracic interbody fusion (PTIF) by bilateral total facetectomies with pedicle screw fixation. The objectives of this retrospective study are to demonstrate the surgical outcomes of PTIF for TDH. MATERIALS AND METHODS: We enrolled 11 patients who underwent PTIF for myelopathy due to TDH and were followed for at least 1 year. The mean age at surgery was 55.2 years and the average period of follow-up was 4.3 years. The levels of operation were T10-T11 in three cases, T12-L1 in three, and T2-T3, T3-T4, T9-T10, T11-T12, and T10-T12 in one case, respectively. The pre- and postoperative clinical status was evaluated according to the modified Frankel grade and the Japanese Orthopaedic Association (JOA) score modified for thoracic myelopathy. Additionally, postoperative complications were assessed. Local kyphosis at the operated segment and status of fusion were evaluated using plain radiographs and computed tomography. RESULTS: Improvement of at least one modified Frankel grade was observed in all but one patient. Average pre- and postoperative JOA scores were 4.9 and 8.8 points, respectively. The average recovery rate was 61%. Bony union was observed in ten cases. One patient's postsurgical outcome resulted in pseudoarthrosis, which required revision surgery due to kyphosis deterioration. Cerebrospinal fluid leakage was observed in one patient postoperatively with neither neurological deficit nor evidence of infection. CONCLUSION: PTIF has produced satisfactory outcomes for myelopathy due to TDH. Therefore, PTIF is one of the surgical treatments of choice for patients with TDH causing myelopathy.

Surgical outcomes of osteoporotic vertebral collapse: a retrospective study of anterior spinal fusion and pedicle subtraction osteotomy.

The purpose of this retrospective study was to demonstrate the surgical outcomes of anterior spinal fusion (ASF) and posterior subtraction osteotomy (PSO) for osteoporotic vertebral collapse (OVC). Forty patients who underwent surgery for OVC at the thoracolumbar junction with neurological deficits were included in this study. ASF was primarily chosen for patients without vertebral compression fracture at other levels, and PSO was chosen for patients with more severe kyphosis or with multiple vertebral fractures. ASF was performed in 26 patients and PSO was performed in 14 patients. We evaluated the pre- and postoperative clinical status consisting of pain, gait, paralysis, and bladder function analysis. Additionally, pre- and postoperative kyphosis, correction angle, correction loss, and upright balance were investigated radiologically. Improvements in pain level, gait, paralysis, and bladder function were obtained in both groups. Average correction angles in the ASF and PSO groups were 16 and 37, respectively. Average correction losses at the final follow-up in the ASF and PSO groups were 7 and 13, respectively. Newly developed postsurgical vertebral compression fracture adjacent to the level of instrumentation was observed in four patients (15%) in the ASF group and in 11 patients (79%) from the PSO group. ASF provided satisfactory outcomes for patients with thoracolumbar OVC, who have no vertebral compression fracture at other levels. Although PSO has benefits for the correction of kyphosis, several problems persist with this procedure, especially for patients with severe osteoporosis.

Clinical classification of patients with lumbar spinal stenosis based on their leg pain syndrome: its correlation with 2-year surgical outcome.

STUDY DESIGN: Prospective follow-up and retrospective review of 174 patients surgically treated for degenerative lumbar spinal stenosis. OBJECTIVE: To examine whether the type of leg pain syndrome associated with lumbar spinal stenosis is correlated with outcome. SUMMARY OF BACKGROUND DATA: Although classifying patients based on their leg pain syndrome is useful in planning surgical decompression, there is no validated method of classification and its prognostic significance remains unknown. METHODS: Based on the type of leg pain, the patients were classified into 2 groups: unilateral and bilateral. Improvement in functional status was evaluated using the Quebec Back Pain Disability Scale; the symptoms were rated on a visual analog scale and the change from baseline to 2-year evaluation was noted. Associations between score changes and baseline variables were examined using multivariate analysis. RESULTS: The type of leg pain was independently associated with improvements in function and leg symptom scores but was not associated with improvement in the back pain score. After surgery, patients with unilateral leg pain had significantly greater improvements in function and leg symptoms than patients with bilateral leg pain. CONCLUSION: In patients undergoing surgery for degenerative lumbar spinal stenosis, the preoperative type of leg pain predicts function and leg symptom outcomes.