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10:46 OPA 1. Surgical Treatment for Unstable Low-Grade Isthmic Spondylolisthesis in Adults: A Prospective Controlled Study of Posterior Instrumented Fusion Compared With Combined Anterior-Posterior Fusion
58S
Proceedings of the NASS 21st Annual Meeting / The Spine Journal 6 (2006) 1S–161S
and one reoperation (foraminotomy) in the ACDF group. Nurick grades will be presented for each disc study separately: First Disc Study: By 12 months, 39% of the arthroplasty and 33% of the ACDF patients had improvement in their Nurick grades, with the rest unchanged (pO.05). Of the patients with 2 year follow-up, 46% vs. 50% (arthroplasty vs. ACDF) noted improvement, with the rest unchanged (pO.05). Second Disc Study: By 12 months, 45% of the arthroplasty and 30% of the ACDF patients had improvement in their Nurick grades, 1 ACDF worsened a grade, and the rest were unchanged (pO.05). Of the patients with 2 year follow-up, 50% versus 38% (arthroplasty vs. ACDF) noted improvement, with the rest unchanged (pO.05). CONCLUSIONS: We found that the improvement in the Nurick grade, as well as all the various outcome measures, were equivalent between the disc and fusion groups, with no worsening of myelopathy in the arthroplasty group. This suggests that at 1 and 2 years postoperatively, with thorough decompression, arthroplasty is equal to ACDF at treating cervical myelopathy for single-level pathology localized to the disc space. It should be noted, however, that none of these patients had compression behind the vertebral body such as from OPLL. FDA DEVICE/DRUG STATUS: IDE artificial disc: Investigational/not approved. CONFLICT OF INTEREST: Author (KDR) Consultant: Medtronic Sofamor Danek; Author (KDR) Grant/Research Support: Medtronic Sofamor Danek.
RESULTS: Baseline demographic and clinical factors were well matched in the two cohorts. At 2 years, 46 posterior-only fusion subjects and 47 combined fusion subjects completed the full follow-up regimen. Outcomes were better by all measures at 6 months and 12 months in the anterior-posterior cohort. Comparing the primary outcome measure (ODI outcome #20) in the posterior versus the combined groups, success was achieved at 6 months in 11 vs. 30 (RR52.67, 95% CI 1.53, 4.67; p5.0001); at 1 year, 20 vs. 34 (RR51.66, 95% CI 1.14, 2.42; p!.005); and at 2 years, 29 vs. 36 subjects (RR51.21, 95% CI 0.93, 1.59; p5.14). At 6 months, 13 posterior-only and 25 combined group subjects had returned to work (RR 1.88, 95% CI 1.10, 3.21; p5.01). More patients achieved their preoperatively determined minimum-acceptable outcome at each time point. There were 3 nonunions in the posterior-alone cohort and 1 in the combined group. Serious complications and re-operations were similar in both groups. CONCLUSIONS: Outcomes up to 2 years were superior by clinically important differences after a combined anterior-posterior operation compared with posterior alone surgery for unstable spondylolisthesis; however, betweengroup differences attenuated appreciably after 6 months. The apparent clinical and occupational benefits of combined fusion should be considered along with possible increases in minor complications and procedure-related costs. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2006.06.148
doi: 10.1016/j.spinee.2006.06.146
Friday, September 29, 2006 10:46–11:36 AM 2006 NASS Outstanding Paper Awards 10:46 OPA 1. Surgical Treatment for Unstable Low-Grade Isthmic Spondylolisthesis in Adults: A Prospective Controlled Study of Posterior Instrumented Fusion Compared With Combined AnteriorPosterior Fusion Justin Swan, MD, Eugene Carragee, MD, Farbod Malek, MD, Erica van den Haak, BS, Ivan Cheng, MD, Todd Alamin, MD, Eric Hurwitz, DC, PhD; Stanford University Medical Center, Stanford, CA BACKGROUND CONTEXT: The surgical treatment for low-grade isthmic spondylolisthesis in adults with intractable lumbar pain is usually spinal fusion. It has been postulated that anterior column reconstruction may be relatively advantageous in those patients with unstable slips. PURPOSE: To compare the early and medium term treatment efficacy of two common fusion techniques in isthmic spondylolisthesis. STUDY DESIGN/SETTING: Prospective controlled trial comparing single-level posterior-lateral instrumented fusion with combined anterior and posterior-lateral instrumented fusion in sequential matched cohorts of patients with radiographically unstable isthmic spondylolisthesis. OUTCOME MEASURES: Primary outcome measure of success was an Oswestry Disability Index (ODI) #20. Secondary outcome measures included patient determined minimum-acceptable outcome on four questionnaires: pain intensity (VAS), ODI, medication intake, and work status. Radiographic outcome of fusion was determined by radiographic union and motion on flexion/extension X-rays. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for primary outcome of success for combined fusion compared with posterior fusion. METHODS: The study was conducted over a six-year period. The first cohort of 50 consecutive patients was treated with a single-level instrumented posterior-lateral fusion; the second sequential cohort was treated with an anterior interbody fusion and the same posterior operation. Observations were made at baseline, 6 months, 1 year, and 2 years after surgery. Final radiographic assessment was made at 2 years after surgery.
10:57 OPA 2. Osteogenic Differentiation of Adipose-Derived Stromal Cells Treated With GDF-5 Cultured on a Novel Three-Dimensional Sintered Microsphere Matrix Francis H. Shen, MD1,2, Qing Zeng, MD2, Qing Lv, MS2, Luke Choi, MD1, Gary Balian, PhD2,3, Xudong Li, MD, PhD2, Cato T. Laurencin, MD, PhD1,2,3,4,5; 1Department of Orthopaedic Surgery, School of Medicine, University of Virginia, Charlottesville, VA; 2Orthopaedic Research Laboratories, University of Virginia, Charlottesville, VA; 3Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA; 4Department of Biomedical Engineering, University of Virginia, Charlottesville, VA; 5Department of Chemical Engineering, University of Virginia, Charlottesville, VA BACKGROUND CONTEXT: It is well known that under the proper conditions multipotential bone marrow stromal cells are capable of osteogenic differentiation. Recently studies have demonstrated that an analogous subpopulation of cells exist within adipose tissue. Although early studies characterizing these adipose-derived stromal (ADS) cells in culture exist, investigations exploring the characteristics and viability of these cells cultured on a three-dimensional sintered microsphere matrix are absent. PURPOSE: To characterize and investigate the viability of ADS cells cultured on bioengineered three-dimensional Sintered Microsphere Matrices (SMM). STUDY DESIGN: Basic science, laboratory study. PATIENT SAMPLE: Sixty SMM total. Six underwent examination by scanning electron microscopy (SEM); 18 for cellular viability; 18 for biochemical assay; and 18 for evaluation by gene expression. OUTCOME MEASURES: The SMM were examined under SEM to evaluate for adherence, migration, and proliferation at 7, 14, and 28 days. Cellular viability was assessed using colorimetric assay for mitochondrial dehydrogenase activity in viable cells (MTS assay) at each corresponding time point. Osteoblastic differentiation was determined using biochemical assays for alkaline phosphatase activity and gene expression for alkaline phosphatase (ALP), osteocalcin (OC), and core binding factor alpha-1 (Cbfa1). METHODS: Multipotential ADS cells from adult Sprague-Dawley rats were isolated and maintained in media. Sintered microsphere matrices of poly (lactide-co-glycolide) [85:15] were prepared using solvent evaporation technique followed by mechanical sieving and fabricated by heating in metal molds. ADS cells were then seeded on the SMM and cultured in media with
Proceedings of the NASS 21st Annual Meeting / The Spine Journal 6 (2006) 1S–161S
and one reoperation (foraminotomy) in the ACDF group. Nurick grades will be presented for each disc study separately: First Disc Study: By 12 months, 39% of the arthroplasty and 33% of the ACDF patients had improvement in their Nurick grades, with the rest unchanged (pO.05). Of the patients with 2 year follow-up, 46% vs. 50% (arthroplasty vs. ACDF) noted improvement, with the rest unchanged (pO.05). Second Disc Study: By 12 months, 45% of the arthroplasty and 30% of the ACDF patients had improvement in their Nurick grades, 1 ACDF worsened a grade, and the rest were unchanged (pO.05). Of the patients with 2 year follow-up, 50% versus 38% (arthroplasty vs. ACDF) noted improvement, with the rest unchanged (pO.05). CONCLUSIONS: We found that the improvement in the Nurick grade, as well as all the various outcome measures, were equivalent between the disc and fusion groups, with no worsening of myelopathy in the arthroplasty group. This suggests that at 1 and 2 years postoperatively, with thorough decompression, arthroplasty is equal to ACDF at treating cervical myelopathy for single-level pathology localized to the disc space. It should be noted, however, that none of these patients had compression behind the vertebral body such as from OPLL. FDA DEVICE/DRUG STATUS: IDE artificial disc: Investigational/not approved. CONFLICT OF INTEREST: Author (KDR) Consultant: Medtronic Sofamor Danek; Author (KDR) Grant/Research Support: Medtronic Sofamor Danek.
RESULTS: Baseline demographic and clinical factors were well matched in the two cohorts. At 2 years, 46 posterior-only fusion subjects and 47 combined fusion subjects completed the full follow-up regimen. Outcomes were better by all measures at 6 months and 12 months in the anterior-posterior cohort. Comparing the primary outcome measure (ODI outcome #20) in the posterior versus the combined groups, success was achieved at 6 months in 11 vs. 30 (RR52.67, 95% CI 1.53, 4.67; p5.0001); at 1 year, 20 vs. 34 (RR51.66, 95% CI 1.14, 2.42; p!.005); and at 2 years, 29 vs. 36 subjects (RR51.21, 95% CI 0.93, 1.59; p5.14). At 6 months, 13 posterior-only and 25 combined group subjects had returned to work (RR 1.88, 95% CI 1.10, 3.21; p5.01). More patients achieved their preoperatively determined minimum-acceptable outcome at each time point. There were 3 nonunions in the posterior-alone cohort and 1 in the combined group. Serious complications and re-operations were similar in both groups. CONCLUSIONS: Outcomes up to 2 years were superior by clinically important differences after a combined anterior-posterior operation compared with posterior alone surgery for unstable spondylolisthesis; however, betweengroup differences attenuated appreciably after 6 months. The apparent clinical and occupational benefits of combined fusion should be considered along with possible increases in minor complications and procedure-related costs. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2006.06.148
doi: 10.1016/j.spinee.2006.06.146
Friday, September 29, 2006 10:46–11:36 AM 2006 NASS Outstanding Paper Awards 10:46 OPA 1. Surgical Treatment for Unstable Low-Grade Isthmic Spondylolisthesis in Adults: A Prospective Controlled Study of Posterior Instrumented Fusion Compared With Combined AnteriorPosterior Fusion Justin Swan, MD, Eugene Carragee, MD, Farbod Malek, MD, Erica van den Haak, BS, Ivan Cheng, MD, Todd Alamin, MD, Eric Hurwitz, DC, PhD; Stanford University Medical Center, Stanford, CA BACKGROUND CONTEXT: The surgical treatment for low-grade isthmic spondylolisthesis in adults with intractable lumbar pain is usually spinal fusion. It has been postulated that anterior column reconstruction may be relatively advantageous in those patients with unstable slips. PURPOSE: To compare the early and medium term treatment efficacy of two common fusion techniques in isthmic spondylolisthesis. STUDY DESIGN/SETTING: Prospective controlled trial comparing single-level posterior-lateral instrumented fusion with combined anterior and posterior-lateral instrumented fusion in sequential matched cohorts of patients with radiographically unstable isthmic spondylolisthesis. OUTCOME MEASURES: Primary outcome measure of success was an Oswestry Disability Index (ODI) #20. Secondary outcome measures included patient determined minimum-acceptable outcome on four questionnaires: pain intensity (VAS), ODI, medication intake, and work status. Radiographic outcome of fusion was determined by radiographic union and motion on flexion/extension X-rays. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for primary outcome of success for combined fusion compared with posterior fusion. METHODS: The study was conducted over a six-year period. The first cohort of 50 consecutive patients was treated with a single-level instrumented posterior-lateral fusion; the second sequential cohort was treated with an anterior interbody fusion and the same posterior operation. Observations were made at baseline, 6 months, 1 year, and 2 years after surgery. Final radiographic assessment was made at 2 years after surgery.
10:57 OPA 2. Osteogenic Differentiation of Adipose-Derived Stromal Cells Treated With GDF-5 Cultured on a Novel Three-Dimensional Sintered Microsphere Matrix Francis H. Shen, MD1,2, Qing Zeng, MD2, Qing Lv, MS2, Luke Choi, MD1, Gary Balian, PhD2,3, Xudong Li, MD, PhD2, Cato T. Laurencin, MD, PhD1,2,3,4,5; 1Department of Orthopaedic Surgery, School of Medicine, University of Virginia, Charlottesville, VA; 2Orthopaedic Research Laboratories, University of Virginia, Charlottesville, VA; 3Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA; 4Department of Biomedical Engineering, University of Virginia, Charlottesville, VA; 5Department of Chemical Engineering, University of Virginia, Charlottesville, VA BACKGROUND CONTEXT: It is well known that under the proper conditions multipotential bone marrow stromal cells are capable of osteogenic differentiation. Recently studies have demonstrated that an analogous subpopulation of cells exist within adipose tissue. Although early studies characterizing these adipose-derived stromal (ADS) cells in culture exist, investigations exploring the characteristics and viability of these cells cultured on a three-dimensional sintered microsphere matrix are absent. PURPOSE: To characterize and investigate the viability of ADS cells cultured on bioengineered three-dimensional Sintered Microsphere Matrices (SMM). STUDY DESIGN: Basic science, laboratory study. PATIENT SAMPLE: Sixty SMM total. Six underwent examination by scanning electron microscopy (SEM); 18 for cellular viability; 18 for biochemical assay; and 18 for evaluation by gene expression. OUTCOME MEASURES: The SMM were examined under SEM to evaluate for adherence, migration, and proliferation at 7, 14, and 28 days. Cellular viability was assessed using colorimetric assay for mitochondrial dehydrogenase activity in viable cells (MTS assay) at each corresponding time point. Osteoblastic differentiation was determined using biochemical assays for alkaline phosphatase activity and gene expression for alkaline phosphatase (ALP), osteocalcin (OC), and core binding factor alpha-1 (Cbfa1). METHODS: Multipotential ADS cells from adult Sprague-Dawley rats were isolated and maintained in media. Sintered microsphere matrices of poly (lactide-co-glycolide) [85:15] were prepared using solvent evaporation technique followed by mechanical sieving and fabricated by heating in metal molds. ADS cells were then seeded on the SMM and cultured in media with