Effectiveness of Epidural Balloon Neuroplasty in Patients With Chronic Spinal Stenosis Accompanied by Redundant Nerve Roots: A Longitudinal Cohort Study.

BACKGROUND: Symptomatic patients with chronic lumbar spinal stenosis (LSS) accompanied by redundant nerve roots (RNR) have poor treatment outcomes. Recently, epidural balloon neuroplasty has been shown to be effective in patients with chronic LSS. OBJECTIVE: To evaluate the effectiveness of epidural balloon neuroplasty in patients with chronic LSS accompanied by RNR. STUDY DESIGN: Retrospective cohort study. SETTING: A single pain clinic of a tertiary medical center in Seoul, Republic of Korea. METHODS: Patients with chronic LSS were divided into groups with (RNR group) and without RNR (non-RNR group). The generalized estimating equations (GEE) model was used to evaluate the effectiveness of epidural balloon neuroplasty in both groups based on Numeric Rating Scale (NRS-11) score for pain intensity, Medication Quantification Scale III (MQS III), and proportion of functional improvement at one, 3, and 6 months postprocedure. RESULTS: GEE analyses showed a significant reduction of pain intensity in NRS-11 and functional improvement compared to baseline throughout the 6-month follow-up period in both groups (P < 0.001), without differences between groups. After adjusting for potential confounding variables, the NRS-11 of leg pain one month after the procedure in the RNR group was reduced less than that in the non-RNR group (P = 0.016), although we did not find a significant time and group interaction. After adjustment, less functional improvement was observed 3 months after the procedures in the RNR group than in the non-RNR group (P = 0.001), with a significant interaction between time and group (P = 0.003). The estimated mean MQS III values were unchanged at 6 months regardless of adjustment in both groups. LIMITATIONS: Retrospective design and a lack of information on adjuvant nonpharmacologic therapies. CONCLUSION: Epidural balloon neuroplasty may be an effective option for reducing pain in patients with chronic LSS accompanied by RNR.

The Role of the Ligamentum Flavum Area as a Morphological Parameter of Lumbar Central Spinal Stenosis.

BACKGROUND: Hypertrophy of the ligamentum flavum (LF) has been considered as a major cause of lumbar central spinal stenosis (LCSS). Previous studies have found that ligamentum flavum thickness (LFT) is correlated with aging, disc degeneration, and lumbar spinal stenosis. However, hypertrophy is different from thickness. Thus, to evaluate hypertrophy of the whole LF, we devised a new morphological parameter, called the ligamentum flavum area (LFA). OBJECTIVES: We hypothesized that the LFA is a key morphologic parameter in the diagnosis of LCSS. STUDY DESIGN: Retrospective observational study. SETTING: The single center study in Seoul, Republic of Korea. METHODS: LF samples were collected from 166 patients with LCSS, and from 167 controls who underwent lumbar magnetic resonance imaging (MRI) as part of a routine medical examination. T1-weighted axial MR imageswere acquired at the facet joint level from individual patients. We measured the LFA and LFT at the L4-L5 intervertebral level on MRI using a picture archiving and communications system. The LFA was measured as the cross-sectional area of the whole LF at the L4-L5 stenotic level. The LFT was measured by drawing a line along the side of the ligament facing the spinal canal and along the laminar side of the ligament curve and then measuring the thickest point at the L4-L5 level. RESULTS: The average LFA was 96.56 ± 30.74 mm2 in the control group and 132.69 ± 32.68 mm2 in the LCSS group. The average LFT was 3.61 ± 0.72 mm in the control group and 4.24 ± 0.97 mm in the LCSS group. LCSS patients had significantly higher LFA (P < 0.001) and LFT (P < 0.001). Regarding the validity of both LFA and LFT as predictors of LCSS, Receiver Operator Characteristics (ROC) curve analysis showed that the best cut-off point for the LFA was 105.90 mm2, with 80.1% sensitivity, 76.0% specificity, and area under the curve (AUC) of 0.83 (95% CI, 0.78 - 0.87). The best cut off-point of the LFT was 3.74 mm, with 70.5% sensitivity, 66.5% specificity, and AUC of 0.72 (95% CI, 0.66 - 0.77). LIMITATIONS: The principal methodological limitation was the retrospective observational nature. Anatomically, degenerative lumbar spinal stenosis can involve the central canal, foramina, and lateral recess. However, we focused on LCSS only. CONCLUSIONS: Although the LFT and LFA were both significantly associated with LCSS, the LFA was a more sensitive measurement parameter. Thus, to evaluate LCSS patients, the treating doctor should more carefully analyze the LFA than LFT.Institutional Review Board (IRB) approval number: S2015-1328-0001Key words: Ligamentum flavum, ligamentum flavum area, ligamentum flavum thickness, lumbar central spinal stenosis, hypertrophy of the ligamentum flavum, morphological parameter, cross-sectional area, optimal cut-off point.

Optimal Angle of Contralateral Oblique View in Cervical Interlaminar Epidural Injection Depending on the Needle Tip Position.

BACKGROUND: Chronic neck and upper extremity pain associated with cervical origin is common, and cervical interlaminar epidural steroid injections (CILESIs) are frequently used to manage the symptoms of cervical spinal disorders. However, CILESIs are associated with risks such as dural puncture and cord injury. OBJECTIVES: We aimed to determine the optimal needle tip visualization, in order to minimize CILESIs-induced complications. STUDY DESIGN: Retrospective observational study. SETTING: The single center study in Seoul, Republic of Korea. METHODS: Participants were 312 adults with neck or upper extremity pain caused by cervical lesion such as cervical herniated nucleus pulposus (HNPs). They underwent magnetic resonance imaging (MRI). Patients with severe cervical spinal stenosis, prior posterior cervical spine surgery, or other anatomical abnormalities of the vertebral laminae were excluded from the study. By using axial T2-weighted spin-echo MRI, we defined the area between the spinous processes as the anterior posterior zone 1 (APZ1), and the area lateral to the spinous processes as the anterior posterior zone 2 (APZ2). Line 1 was drawn along the ventral margin of lamina that confined APZ1, and line 2 was similarly drawn in order to define APZ2. The angles between the midsagittal line and lines 1 and 2 were defined as angle 1 and angle 2, respectively. Angles were measured at the C5-6, C6-7, and C7-T1 levels, on both right and left sides at each level. RESULTS: Angle 1 values (in degrees) at right C5-6, left C5-6, right C6-7, left C6-7, right C7-T1, and left C7-T1 were 62.54 ± 10.52, 64.34 ± 9.86, 62.03 ± 10.27, 62.87 ± 10.64, 61.64 ± 11.0, and 62.58 ± 10.83, respectively. Angle 2 values at right C5-6, left C5-6, right C6-7, left C6-7, right C7-T1, and left C7-T1 were 50.44 ± 6.84, 50.77 ± 7.00, 49.15 ± 6.07, 49.89 ± 6.45, 50.84 ± 6.68, and 50.24 ± 6.60, respectively. There were significant differences between angles 1 and 2 at each level. LIMITATIONS: This study is a retrospective review and did not employ controls, blinding, or randomization. Additionally, the optimal CLO angles for CILESIs and cervicothoracic interlaminar epidural steroid injections (CTILESIs) have not been assessed in clinical studies. Another limitation is that we divided lamina into only APZ1 and APZ2. CONCLUSIONS: During CILESIs, a contralateral oblique (CLO) view at 60 degrees is superior to other angles for visualizing the epidural space when the needle tip is placed in the interlaminar space and within the spinous processes margin. When the needle tip is placed in the interlaminar space and lateral to the spinous processes, a CLO view at 50 degrees is most appropriate.Institutional Review Board (IRB) approval number: S2016-0390-0001Key words: Chronic neck pain, chronic upper extremity pain, cervical epidural injections, cervical interlaminar steroid injections, steroid, needle tip position, needle tip visualization, fluoroscopy, complication, contralateral oblique view.

Effect of Epidural Steroid Injection on Bone Mineral Density in Postmenopausal Women According to Antiosteoporotic Medication Use.

BACKGROUND: No studies to date have compared bone mineral density (BMD) changes after epidural steroid injection (ESI) between postmenopausal patients taking antiosteoporotic medication and those who are not. OBJECTIVE: The aim of the present study was to analyze the relationship between ESI and BMD changes in postmenopausal patients according to antiosteoporotic medication use. STUDY DESIGN: Retrospective analysis. SETTING: Department of Anesthesiology and Pain Medicine at Asan Medical Center, Korea. METHODS: We retrospectively analyzed postmenopausal women who underwent ESI using dexamethasone. All women had received a diagnosis of lumbar spinal stenosis and their BMD had been measured before and after treatment. BMD was evaluated by dual-energy x-ray absorptiometry at the lumbar spine, femoral neck, femoral trochanter, and total femur, and was recorded as absolute g/cm2 and T-scores. A total of 126 patients were included in the final analysis. ESI patients were grouped as follows: group 1 (n = 74) ESI patients who took antiosteoporotic medication; group 2 (n = 52) ESI patients who did not take antiosteoporotic medication. RESULTS: In group 1, there were no significant differences between baseline and post-treatment BMD absolute values (g/cm2) in the lumbar spine, femoral neck, femoral trochanter, and total femur. In group 2, significant changes in the post-treatment BMD absolute values (g/cm2) from baseline were observed in the femoral neck (-1.48 ± 3.84%), femoral trochanter (-2.80 ± 7.50%), and total femur (-2.23 ± 4.52%), but not in the lumbar spine (-2.23 ± 4.52%). LIMITATIONS: This study contained a small sample size, no control group, and no long-term follow-up of the BMD changes after ESI. CONCLUSIONS: Our data provide new evidence indicating that ESI causes BMD changes in postmenopausal women who do not take antiosteoporotic medication. Thus, we recommend that prophylactic antiosteoporotic treatment be considered for postmenopausal women who require ESI treatment.

The predictive performance of infusion strategy nomogram based on a fluid kinetic model.

BACKGROUND: In a previous study, fluid kinetic models were applied to describe the volume expansion of the fluid space by administration of crystalloid and colloid solutions. However, validation of the models were not performed, it is necessary to evaluate the predictive performance of these models in another population. METHODS: Ninety five consenting patients undergoing elective spinal surgery under general anesthesia were enrolled in this study. These patients were randomly assigned to three fluid groups i.e. Hartmann's solution (H group, n = 28), Voluven® (V group, n = 34), and Hextend® (X group, n = 33). After completion of their preparation for surgery, the patients received a loading and maintenance volume of each fluid predetermined by nomograms based on fluid pharmacokinetic models during the 60-minute use of an infusion pump. Arterial samples were obtained at preset intervals of 0, 10, 20, and 30 min after fluid administration. The predictive performances of the fluid kinetic modes were evaluated using the fractional change of arterial hemoglobin. The relationship between blood-volume dilution and target dilution of body fluid space was also evaluated using regression analysis. RESULTS: A total of 194 hemoglobin measurements were used. The bias and inaccuracy of these models were -2.69 and 35.62 for the H group, -1.53 and 43.21 for the V group, and 9.05 and 41.82 for the X group, respectively. The blood-volume dilution and target dilution of body-fluid space showed a significant linear relationship in each group (P < 0.05). CONCLUSIONS: Based on the inaccuracy of predictive performance, the fluid-kinetic model for Hartmann's solution showed better performance than the other models.