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Radiographic Analysis of the Lumbosacral Spine: Is There a Critical Sacral Angle for Total Disc Replacement?
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S level above the lumbosacral junction (p!0.02) and was observed more frequently at index-levels than at non-index levels (p!0.001). The degenerative changes were associated with a negative influence on postoperative outcome parameters VAS and ODI (p!0.03) that were already detected early postoperatively. The mean postoperative ROM was significantly lower in patients with FJD in comparison to the remaining cohort (p!0001). CONCLUSIONS: Total lumbar disc replacement (TDR) proved to have a beneficial effect with regard to adjacent segment preservation. Progressive index-level facet joint degeneration (FJD) was observed in a considerable number of patients, particularly at the lumbosacral junction. Lower segmental mobility and less favorable clinical results point to the fact that a particular cohort of patients may predominantly be affected in which TDR shows inferior compatibility with the index-segment’s biomechanics. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.241
91S
RESULTS: The SS and PI values were obtained in 55 patients. The average SS was 33.3 and average PI was 39.6 (normal range SS5416 8.4 , PI555610.6 ). Intracorrelations among these parameters were evaluated with the various clinical outcomes. At 24 month follow-up, no significant correlation (p$.05) was observed between average SS and ODI, SS and VAS, PI and ODI, and PI and VAS. There were also no significant correlations (p$.05) between SS and PI and any of the average adjusted measures (aODI and aVASpain). BMI, age, gender did not explain any variability in the relationship between clinical outcome measures and SS and PI. CONCLUSIONS: Concern whether TDR is an appropriate treatment for patients with steep sacral slopes has not previously been investigated. We reviewed a large range of sacral slope angles (from 22 to 61 ) and found no association between SS or PI and clinical outcomes after treatment with an artificial disc at L5/S1. In addition, there was no intrarelationship between SS, BMI, and clinical outcomes. These preliminary results demonstrate maintenance of pain relief and functional improvement with TDR in a wide range of sacral slope angles, suggesting steeper angles are not a contraindication for TDR. Further research incorporating longer-term clinical results are necessary to provide more insight into this clinically important question. FDA DEVICE/DRUG STATUS: Prodisc-L: Approved for this indication.
196. Radiographic Analysis of the Lumbosacral Spine: Is There a Critical Sacral Angle for Total Disc Replacement? Rattalerk Arunakul, MD, Melodie Metzger, PhD, Linda E.A. Kanim, MA, Hyun Bae, MD, Michael A. Kropf, MD, Rick B. Delamarter, MD; CedarsSinai Medical Center, Spine Center, Los Angeles, CA, USA
doi: 10.1016/j.spinee.2010.07.242
BACKGROUND CONTEXT: The lumbosacral juncture presents unique biomechanical challenges to TDR due to its orientation and consequential shear loading. While spinal alignment and the degree of lordosis have been correlated with increased risk for lumbosacral degenerative spondylolithesis, it has yet to be investigated in relation to TDR outcomes. Reports of inferior TDR outcomes at L5/S1 compared to the levels above include: increased facet joint pain, decreased post-operative ROM, and greater vertebral translation, suggesting a relationship with the sacral inclination at L5/S1. The purpose of this study was to investigate the relationship between sacral slope obliquity and self-reported clinical outcomes after TDR. PURPOSE: To determine whether there is a correlation between radiographic measurements, including sacral slope (SS) and pelvic incidence (PI), and self-reported clinical outcomes in single level L5/S1 ProDisc-L patients. STUDY DESIGN/SETTING: Retrospective radiographic review of a cohort of patients in a prospective clinical study. PATIENT SAMPLE: 69 patients (age 26–65) who underwent artificial disc replacement at L5/S1 for degenerative disc disease. OUTCOME MEASURES: SS and PI were measured on preoperative and/or initial follow-up standing sagittal radiographs. Outcome measures consisted of visual analog scale (VAS) for pain and Oswestry disability index (ODI). METHODS: Plain standing lateral radiographs were reviewed and selected for view of the femoral head in the radiograph. SI and PI were measured from pre-treatment and initial follow-up standing films (2 weeks). SS was determined as the angle between a horizontal line and the superior endplate of S1. PI was determined as the angle between a line drawn from center of femoral head and a line perpendicular to the superior sacral vertebral endplate. Patient’s self-assessments included ODI and VAS for pain 2 years after ADR. A second outcome measure was computed as the average of scores across time for each patient yielding a stable outcome for each parameter (average adjusted aVASpain, aODI). Correlation coefficients were computed to evaluate relationships among radiographic parameters and self-assessed clinical outcomes. Analysis of covariance was used to evaluate multivariate relationships including radiographic parameters, body mass index (BMI), and clinical outcomes.
197. F.D.A. I.D.E. Prospective Randomized Comparison of Three Lumbar Artificial Disc Replacements (A.D.R.) with Minimum 3-Year Follow-Up Kenneth A. Pettine, MD; The Spine Institute, Loveland, CO, USA BACKGROUND CONTEXT: This is class I data comparing three lumbar ADR. PURPOSE: To establish safety and efficacy between the MaverickÔ (M), Charite´ Ô(C), and KineflexÔ (K) A.D.R.’s. STUDY DESIGN/SETTING: Follow up on three ADR’s performed by two surgeons, at one I.D.E. site were reviewed. PATIENT SAMPLE: Indications for surgery were similar to lumbar fusion. There were 25 Maverick, 31 Charite´, and 35 Kineflex patients. The majority of A.D.R.’s were performed at L5-S1 vs. L4-L5 (M) 19 to 6, (C) 19 to 12 and (K) 28 to 7. Inclusion/exclusion criteria will be discussed. OUTCOME MEASURES: Success was defined as an improvement of 15 or more points in Oswestry Disability Index (ODI) with no revision or device removal and no major device related adverse events. METHODS: Follow up on three ADR’s performed by two surgeons, at one I.D.E. site were reviewed. ODI, VAS, and patient satisfaction were evaluated at pre-op and post-op visits. RESULTS: Re-operations included: (M) 1 infection, (C) 3 implant complications (K) 1 implant complication. These cases will be presented. ODI results for all groups: Pre-op5(M) 57.6, (C) 63.8, and (K) 61.1; One-year post-op5(M) 16.3, (C) 27.3, and (K) 20.4; Three-year postop5(M) 14.6 (p!0.001), (C) 20.5 (p!0.001), and (K) 19.3 (p!0.001). VAS results for all groups: Pre-op5(M) 74.1, (C) 85, (K) 83.9; One year post-op5(M) 27.9, (C) 31.4, and (K) 27.3; Three-year post-op5(M) 20.5 (p!0.001), (C) 33.8 (p!0.001), and (K) 26.9 (p!0.001). Clinical success was met in (M) 90%, (C) 83.5%, (K) 90.5% of patients. Patients with a VAS less than 2 occurred in (M) 68%, (C) 29%, (K) 47%. Patients with an ODI less than 10 occurred in (M) 67% (C) 33%, (K) 52%. Patient satisfaction at three-year follow up was (M) 96%, (C) 84%, and (K) 91%. CONCLUSIONS: All three ADR’s demonstrated safety. They all showed efficacy with a statistically significant improvement in ODI and VAS at three year follow-up (p!0.001). F.D.A. clinical success was (M) 90%,
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
91S
RESULTS: The SS and PI values were obtained in 55 patients. The average SS was 33.3 and average PI was 39.6 (normal range SS5416 8.4 , PI555610.6 ). Intracorrelations among these parameters were evaluated with the various clinical outcomes. At 24 month follow-up, no significant correlation (p$.05) was observed between average SS and ODI, SS and VAS, PI and ODI, and PI and VAS. There were also no significant correlations (p$.05) between SS and PI and any of the average adjusted measures (aODI and aVASpain). BMI, age, gender did not explain any variability in the relationship between clinical outcome measures and SS and PI. CONCLUSIONS: Concern whether TDR is an appropriate treatment for patients with steep sacral slopes has not previously been investigated. We reviewed a large range of sacral slope angles (from 22 to 61 ) and found no association between SS or PI and clinical outcomes after treatment with an artificial disc at L5/S1. In addition, there was no intrarelationship between SS, BMI, and clinical outcomes. These preliminary results demonstrate maintenance of pain relief and functional improvement with TDR in a wide range of sacral slope angles, suggesting steeper angles are not a contraindication for TDR. Further research incorporating longer-term clinical results are necessary to provide more insight into this clinically important question. FDA DEVICE/DRUG STATUS: Prodisc-L: Approved for this indication.
196. Radiographic Analysis of the Lumbosacral Spine: Is There a Critical Sacral Angle for Total Disc Replacement? Rattalerk Arunakul, MD, Melodie Metzger, PhD, Linda E.A. Kanim, MA, Hyun Bae, MD, Michael A. Kropf, MD, Rick B. Delamarter, MD; CedarsSinai Medical Center, Spine Center, Los Angeles, CA, USA
doi: 10.1016/j.spinee.2010.07.242
BACKGROUND CONTEXT: The lumbosacral juncture presents unique biomechanical challenges to TDR due to its orientation and consequential shear loading. While spinal alignment and the degree of lordosis have been correlated with increased risk for lumbosacral degenerative spondylolithesis, it has yet to be investigated in relation to TDR outcomes. Reports of inferior TDR outcomes at L5/S1 compared to the levels above include: increased facet joint pain, decreased post-operative ROM, and greater vertebral translation, suggesting a relationship with the sacral inclination at L5/S1. The purpose of this study was to investigate the relationship between sacral slope obliquity and self-reported clinical outcomes after TDR. PURPOSE: To determine whether there is a correlation between radiographic measurements, including sacral slope (SS) and pelvic incidence (PI), and self-reported clinical outcomes in single level L5/S1 ProDisc-L patients. STUDY DESIGN/SETTING: Retrospective radiographic review of a cohort of patients in a prospective clinical study. PATIENT SAMPLE: 69 patients (age 26–65) who underwent artificial disc replacement at L5/S1 for degenerative disc disease. OUTCOME MEASURES: SS and PI were measured on preoperative and/or initial follow-up standing sagittal radiographs. Outcome measures consisted of visual analog scale (VAS) for pain and Oswestry disability index (ODI). METHODS: Plain standing lateral radiographs were reviewed and selected for view of the femoral head in the radiograph. SI and PI were measured from pre-treatment and initial follow-up standing films (2 weeks). SS was determined as the angle between a horizontal line and the superior endplate of S1. PI was determined as the angle between a line drawn from center of femoral head and a line perpendicular to the superior sacral vertebral endplate. Patient’s self-assessments included ODI and VAS for pain 2 years after ADR. A second outcome measure was computed as the average of scores across time for each patient yielding a stable outcome for each parameter (average adjusted aVASpain, aODI). Correlation coefficients were computed to evaluate relationships among radiographic parameters and self-assessed clinical outcomes. Analysis of covariance was used to evaluate multivariate relationships including radiographic parameters, body mass index (BMI), and clinical outcomes.
197. F.D.A. I.D.E. Prospective Randomized Comparison of Three Lumbar Artificial Disc Replacements (A.D.R.) with Minimum 3-Year Follow-Up Kenneth A. Pettine, MD; The Spine Institute, Loveland, CO, USA BACKGROUND CONTEXT: This is class I data comparing three lumbar ADR. PURPOSE: To establish safety and efficacy between the MaverickÔ (M), Charite´ Ô(C), and KineflexÔ (K) A.D.R.’s. STUDY DESIGN/SETTING: Follow up on three ADR’s performed by two surgeons, at one I.D.E. site were reviewed. PATIENT SAMPLE: Indications for surgery were similar to lumbar fusion. There were 25 Maverick, 31 Charite´, and 35 Kineflex patients. The majority of A.D.R.’s were performed at L5-S1 vs. L4-L5 (M) 19 to 6, (C) 19 to 12 and (K) 28 to 7. Inclusion/exclusion criteria will be discussed. OUTCOME MEASURES: Success was defined as an improvement of 15 or more points in Oswestry Disability Index (ODI) with no revision or device removal and no major device related adverse events. METHODS: Follow up on three ADR’s performed by two surgeons, at one I.D.E. site were reviewed. ODI, VAS, and patient satisfaction were evaluated at pre-op and post-op visits. RESULTS: Re-operations included: (M) 1 infection, (C) 3 implant complications (K) 1 implant complication. These cases will be presented. ODI results for all groups: Pre-op5(M) 57.6, (C) 63.8, and (K) 61.1; One-year post-op5(M) 16.3, (C) 27.3, and (K) 20.4; Three-year postop5(M) 14.6 (p!0.001), (C) 20.5 (p!0.001), and (K) 19.3 (p!0.001). VAS results for all groups: Pre-op5(M) 74.1, (C) 85, (K) 83.9; One year post-op5(M) 27.9, (C) 31.4, and (K) 27.3; Three-year post-op5(M) 20.5 (p!0.001), (C) 33.8 (p!0.001), and (K) 26.9 (p!0.001). Clinical success was met in (M) 90%, (C) 83.5%, (K) 90.5% of patients. Patients with a VAS less than 2 occurred in (M) 68%, (C) 29%, (K) 47%. Patients with an ODI less than 10 occurred in (M) 67% (C) 33%, (K) 52%. Patient satisfaction at three-year follow up was (M) 96%, (C) 84%, and (K) 91%. CONCLUSIONS: All three ADR’s demonstrated safety. They all showed efficacy with a statistically significant improvement in ODI and VAS at three year follow-up (p!0.001). F.D.A. clinical success was (M) 90%,
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.