Efficacy of Postoperative Pain Management Using Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site in Patients with Adolescent Idiopathic Scoliosis: A Parallel, Double-Blinded, Randomized Controlled Pilot Trial

Study Design Randomized controlled trial. Objective Adolescent idiopathic scoliosis (AIS) is a common spinal deformity that affects every population. In severe deformity, surgical intervention is performed. Autogenous iliac crest bone graft (ICBG) harvesting remains a common procedure worldwide for scoliosis surgery. Postoperative pain at the ICBG donor site is a major concern in patients undergoing spine surgery that affects postoperative functional outcome and consumes health care resources. Previous studies have noted a decrease in pain and postoperative analgesic use with the application of continuous infusion of anesthetic at the ICBG site in comparison with placebo. However, there is lack of evidence addressing the efficacy of continuous anesthetic infusion at the ICBG site in young patients and in particular those with spinal deformity, such as AIS. As such, this parallel, double-blinded, randomized controlled trial addressed the pain management efficacy of continuous anesthetic infusion versus saline at the ICBG site in patients with AIS during the immediate postoperative period. Methods Participants were randomized into two groups. Group A (control subjects) received 3 mL per hour of saline locally at the ICBG site, and group B (treatment subjects) received a constant rate of infusion of 3 mL per hour of 0.25% levobupivacaine. Both groups received their postoperative intervention for 47 hours. All subjects and outcome assessors were blinded to the type of intervention. Utilizing the visual analog pain scale, pain was assessed at the primary spine surgical site, ICBG site, and contralateral ICBG site. Overall physical pain was assessed by the McGill Pain Questionnaire. The degree of analgesic use and complications were also evaluated. All outcomes were assessed up until the fourth day of the patients' hospitalization following surgery. Results Twelve subjects were recruited (five in group A; seven in group B). No difference was noted at baseline regarding age, weight, height, arm span, sex, curve type, instrumented and fused levels, length of hospitalization, and pain scores between groups. Postoperatively, no difference was noted in surgical site pain between groups (p > 0.05). However, decreased ICBG and contralateral ICBG pain decreased twofold in group B patients in comparison with group A. Similarly, group B subjects had notably decreased postoperative overall pain scores (group A, mean 15.3; group B, mean 3.8). No significant differences were noted for the pain scores due to the small sample size. Conclusions This study is the first with a robust level I study design to assess the efficacy of continuous infusion of analgesia into the ICBG site in young patients with AIS. This pilot study noted a trend that continuous anesthetic infusion reduces pain at the ICBG site and may further decrease overall physical bodily pain. This study further established a sample size calculation to facilitate large-scale studies addressing these parameters. This study provides further support of postoperative pain management options for children with spinal deformities.published_or_final_versio

Efficacy of postoperative pain management of the lliac crest bone graft harvesting site in adolescent idiopathic scoliosis patients: a parallel, double-blinded, randomized controlled trial

Session - Free Papers Conservative Treatment: abstract no. 40110Rationale: Autogenous iliac crest bone graft (ICBG) harvesting is a common procedure utilized for scoliosis surgery. Postoperative pain at the ICBG donor-site is a major concern. The following is a parallel, double-blinded, randomized controlled trial addressing the pain management efficacy of continuous anesthetic infusion versus saline at the ICBG site in AIS patients during the immediate postoperative period was addressed. Methods: A Level I trial design of AIS patients (age range: 10 to 18 years of age) undergoing posterior instrumentation and fusion at a single institute was performed. Participants were randomized into two groups. Group A consisted of control subjects who received 3ml per hour of saline locally at the ICBG site and Group B consisted of treatment subjects who received a constant rate of infusion of 3ml/hour of 0.25% levobupivacaine. Results: Twelve subjects were recruited (n=5 Group A; 7 Group B). No difference was noted at baseline between groups and parameters. Postoperatively, no difference was noted in surgical site pain between groups (p>0.05). However, decreased ICBG and contralateral ICBG pain decreased two-fold in Group B patients in comparison to Group A. Similarly Group B subjects had notably decreased postoperative overall pain scores. No significant differences were noted for the pain scores due to the small sample size. Conclusions: This pilot study noted a trend that continuous anesthetic infusion reduces pain at the ICBG site and may further decrease overall physical bodily pain. This study further established a sample size calculation to facilitate large-scale studies addressing these parameters

Lumbar Facet Joint Orientation in Degenerative Spondylolisthesis: the Role of Ethnic Variation in Asia Pacific

General PosterINTRODUCTION: Lumbar facet joint orien‐ tation has been reported to be associated with the development of degenerative spondylolisthesis (dSpl). The role of ethnici‐ ty regarding facet joint orientation remains uncertain. As such, the following study was performed across a wide‐ranging popula‐ tion base to assess the role of ethnicity in facet joint orientation in patients with dSpl in the Asia Pacific region. METHODS: A multi‐national, multi‐ethnic cross‐sectional image‐based study was per‐ formed in 34 institutions in Asia Pacific, identifying 448 cases. Lateral standing x‐ rays and axial MRIs and/or CT scans were obtained for patients with lumbar dSpl. Magnitude of slip displacement, level of dSpl, and left/right facet joint angulation, width‐curvature ratio, and gap width were noted on image assessment. Facet joint measurements were performed at each level from L3‐S1. Gender, age, BMI, and ethnicity were also noted.    RESULTS: The study included 389 patients with known ethnic origin (mean age: 61.4 years; 36.7% males, 63.3% females). The mean BMI was 25.6 kg/m2. The level of dSpl was most prevalent at L4/L5 (72.4%). There were 28.8% Indian, 28.5% Japanese, 17.5% Chinese, 8.2% Korean, 6.2% Thai, 4.6% Cau‐ casian, 2.3% Filipino, 2.3% Malay, and 1.3 were of mixed Asian origin. Accounting for patient demographics and displacement, there was a statistically significant differ‐ ence between ethnicity to that of left/right facet joint angulations, width‐curvature ratios, and gap widths from L3‐S1 between specific ethnic groups (p<0.05).    DISCUSSION: This is the largest study to address the role of ethnicity upon lumbar facet joint orientation in dSpl. Ethnicity plays a role in facet joint orientation and may influence the occurrence and severity of dSpl or be a potential consequence. An understanding of ethnic variability may be one factor which assists in identifying those patients at risk of postsurgical development or progression of dSpl

Lumbar facet joint orientation in degenerative spondylolisthesis: the role of ethnic variation in the Asia Pacific

Program schedule A020Scientific session: Deformity surger

Is lumbar facet joint tropism developmental or secondary to remodeling changes? An international, large-scale multicenter study by the AOSAP collaboration consortium

Session: Free Papers Spine: Degenerative 1: abstract no. 40328INTRODUCTION: Facet joint tropism is asymmetry in orientation of the bilateral facets. Some studies have shown that tropism may increase the risk of disc degeneration and herniations, as well as degenerative spondylolisthesis (DS). It remains controversial whether FJT is a pre-existing developmental phenomena or secondary to progressive joint remodeling. The following study addressed the occurrence of FJT of the lower lumbar spine (i.e. L3-S1) in a degenerative spondylolisthesis patient model. METHODS: This was an international, multi-center cross-sectional study of 267 patients with single level DS recruited from 33 spine institutes in Asia Pacific. FJT (≥8 degrees asymmetry) was assessed on MRI from L3-S1 and in relation to the level of DS. Patient demographic were noted and assessed in relation to FJT of each lumbar segment. RESULTS: 65% were females (mean age of 63 years; mean BMI: 26 kg/m2). FJT was present in 31.3% to 50.6% of DS levels. FJT involved 33.3% to 58.8% of the one or two non-DS levels adjacent to the DS level. Patient demographics were not found to be significantly related to FJT at any level (p>0.05). CONCLUSION: To the authors’ knowledge, this is one of the largest studies conducted, in particular in an Asian population, addressing the “origins concept” of FJT. Although levels with DS were noted to have FJT, adjacent levels with no DS also exhibited tropism and were not related to age and other patient demographics. This study suggested that FJT may have a pre-disposed orientation

Facet Joint Tropism and Degenerative Spondylolisthesis—A Study from the AOSAP Research Collaboration

The abstract can be viewed at http://www.spineresearchforum.org/WFSR_2014_Thieme_AbstractBook_with_Cover.pdfConference theme: The Intervertebral Disc - from Degeneration to Therapeutic Motion PreservationShort Talk SessionIntroduction Degenerative spondylolisthesis (dSpl) is translation of the vertebral body in relation to adjacent levels, mainly attributed to degenerative changes of the intervertebral disc and facet joint complexes, and primarily occurs at L4-L5. Studies have suggested that more sagittal oriented facet joints at L4-L5 are associated with dSpl. However, the role of facet joint tropism (i.e., asymmetry between facet joint orientations) in L4-L5 dSpl remains inconclusive, in particular, in an Asian population and possibly attributed to nonstandardized definitions of tropism. As such, the following study addressed the role of facet joint tropism in relation to L4-L5 dSpl in the Asia Pacific region. Materials and Methods A multinational, multiethnic cross-sectional image-based study was performed in 34 institutions in the Asia Pacific region. Lateral standing radiographs and axial MRIs and/or CT scans were obtained for patients diagnosed with lumbar dSpl. Imaging assessment consisted of the following: magnitude of slip displacement, level of spondylolisthesis, and left/right L4- L5 facet joint angulations were noted on image assessment. Patients with single level dSpl were included. Patients were further stratified into those presenting with (Group A) or without (Group B) L4-L5 dSpl. Facet joint tropismwas defined as 7 degrees difference (Grogan et al 1997) between left and right facet joints and also assessed on receiver operating characteristics (ROC) curve analysis to identify critical values for multivariate analysis. Gender, age, weight/height (body mass index [BMI]), and ethnicity were also noted. Results The study included 351 patients (36.9% males and 63.1% females) with a mean age of 61.8 years (range: 24-90 years). The mean BMIwas 25.6 kg/m2 (range: 15.4-43.9 kg/m2). There were 267 patients (76.1%) in Group A and 84 individuals (23.9%) in Group B (control). Sex type (p ¼ 0.295) and BMI (p ¼ 0.227) did not significantly differ between groups, but elevated age was more pronounced with L4-L5 dSpl (p ¼ 0.001). There was a statistically significant difference between right and left L4-L5 facet joint angulations between Group A (right mean: 57.5 degrees; left mean: 55.4 degrees) and Group B (right mean: 48.4 degrees; left mean: 46.5 degrees) (p < 0.001). Based on facet joint tropism of 7 degrees difference between facet angulations, there was no statistically significant difference between groups. ROC analysis identified high sensitivity and specificity of facet joint angulation difference of 15 degrees or greater associated with dSpl. Based on ageadjusted multivariate analysis, facet joint tropism with a critical value of 15 degrees or greater angulation difference noted an odds ratio of 2.34 (95% CI: 1.17-4.67; p ¼ 0.016) associated with dSpl. Slippage was noted with increased facet joint tropism, but the effects could not be discerned. Conclusion Greater sagittal FJ orientationwas associated with dSpl, aswas joint tropism. A critical value of 15 degrees FJ angle difference produced a twofold increased likelihood of dSpl. Our study broadens the understanding of FJ morphology and its role in degenerative sagittal plane instability. Acknowledgments This study was funded by AOSpine Asia Pacific. Disclosure of Interest None declare

Is lumbar facet joint tropism development or secondary to remodeling changes? An international, large-scale multi-centre study by the APSAP collaboration consortium

Session - Free Papers Spine Degenerative 1: abstract no. 40328INTRODUCTION: Facet joint tropism is asymmetry in orientation of the bilateral facets. Some studies have shown that tropism may increase the risk of disc degeneration and herniations, as well as degenerative spondylolisthesis (DS). It remains controversial whether FJT is a pre-existing developmental phenomena or secondary to progressive joint remodeling. The following study addressed the occurrence of FJT of the lower lumbar spine (i.e. L3-S1) in a degenerative spondylolisthesis patient model. METHODS: This was an international, multi-center cross-sectional study of 267 patients with single level DS recruited from 33 spine institutes in Asia Pacific. FJT (≥8 degrees asymmetry) was assessed on MRI from L3-S1 and in relation to the level of DS. Patient demographic were noted and assessed in relation to FJT of each lumbar segment. RESULTS: 65% were females (mean age of 63 years; mean BMI: 26 kg/m2). FJT was present in 31.3% to 50.6% of DS levels. FJT involved 33.3% to 58.8% of the one or two non-DS levels adjacent to the DS level. Patient demographics were not found to be significantly related to FJT at any level (p>0.05). CONCLUSION: To the authors’ knowledge, this is one of the largest studies conducted, in particular in an Asian population, addressing the “origins concept” of FJT. Although levels with DS were noted to have FJT, adjacent levels with no DS also exhibited tropism and were not related to age and other patient demographics. This study suggested that FJT may have a pre-disposed orientation

Facet joint tropism and degenerative spondylolisthesis: a study from the AOSAP Research Collaboration

General Posters GP14

Lumbar Facet Joint Orientation in Degenerative Spondylolisthesis: The Role of Ethnic Variation in Asia Pacific—A Study from the AOSAP Research Collaboration

The abstract can be viewed at http://www.spineresearchforum.org/WFSR_2014_Thieme_AbstractBook_with_Cover.pdfConference theme: The Intervertebral Disc - from Degeneration to Therapeutic Motion PreservationIntroduction Degenerative spondylolisthesis (dSpl) can lead to various symptoms, including low back pain. Lumbar facet joint orientation has been reported to be associated with the development of dSpl. The role of ethnicity regarding facet joint orientation remains uncertain. As such, the following study was performed across a wide-ranging population base to assess the role of ethnicity in facet joint orientation in patients with dSpl in the Asia Pacific region. Materials and Methods A multinational, multiethnic cross-sectional image-based study was performed in 34 institutions in Asia Pacific, identifying 448 cases. Lateral standing X-rays and axial MRIs and/or CT scans were obtained for patients with lumbar dSpl. Magnitude of slip displacement, level of dSpl, and left/right facet joint angulation, width-curvature ratio, and gap width were noted on image assessment. Facet joint measurements were performed at each level from L3-S1. Gender, age, BMI, and ethnicity were also noted. Results The study included 389 patients with known ethnic origin (mean age: 61.4 years; 36.7% males, 63.3% females). The mean BMI was 25.6 kg/m2. The level of dSpl was most prevalent at L4/L5 (72.4%). There were 28.8% Indian, 28.5% Japanese, 17.5% Chinese, 8.2% Korean, 6.2% Thai, 4.6% Caucasian, 2.3% Filipino, 2.3% Malay, and 1.3were of mixed Asian origin. Accounting for patient demographics and displacement, there was a statistically significant difference between ethnicity to that of left/ right facet joint angulations, width-curvature ratios, and gap widths from L3-S1 between specific ethnic groups (p < 0.05). Conclusion This is the largest study to address the role of ethnicity upon lumbar facet joint orientation in dSpl. Ethnicity plays a role in facet joint orientation and may influence the occurrence and severity of dSpl or be a potential consequence. An understanding of ethnic variability may be one factor which assists in identifying those patients at risk of postsurgical development or progression of dSpl. Acknowledgments This study was funded by AOSpine Asia Pacific. Disclosure of Interest None declare