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Access-Related Complications in Anterior Lumbar Surgery Performed by Spinal Surgeons
Proceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 99S–165S Iliac Crest Bone Graft (ICBG) Group (I) vs. Bone Morphogenetic Protein (BMP) Group (II) in long fusions to the sacrum in adult deformity (AD) patients with a minimum of 4 year f/u. PURPOSE: We hypothesized BMP would have lower rates of pseudarthrosis (PSDA) compared to ICBG. STUDY DESIGN/SETTING: Matched-Cohort Study. PATIENT SAMPLE: Adult Deformity. OUTCOME MEASURES: Outcomes were measured by Oswestry Disability Index (ODI) and SRS-30 questionnaires. Office charts were reviewed for any cancers seen in the f/u period. METHODS: Patients (pts) from 1997-2007 who had fusions for AD involving $7 levels with sacropelvic fixation where either ICBG or BMP was used were studied at one institution. Revisions, non-idiopathic deformities, pts receiving both BMP/ICBG were excluded. Outcomes were measured by Oswestry Disability Index (ODI) and SRS-30 questionnaires. Office charts were reviewed for any cancers seen in the f/u period. RESULTS: A total of 63 patients met inclusion criteria for study. Group I had 32 females (F), mean age 52.6 (range 31.0-77.6) with a mean F/U of 8.7 yrs (4.6-14.0). All pts underwent anterior/posterior (A/P) combined surgery. Group II had 30 F, mean age 56.5 (range 39.3-77.4) with a mean f/u of 5.1 yrs (range 4.0-7.7). 9 patients had posterior only surgery while 22 had A/P surgery. Mean levels fused was 11.3 vs. 10.8 (p50.25) and fixation points were 1.5 vs. 1.8 per level for Group I and II respectively (p! 0.01). The rate of PSDA was 6.4% (2/31) BMP vs. 28.1% (9/32) in ICBG (p50.04) and was detected at a mean of 2.4 yr postoperatively (range 0.84.8yrs). In Group II, PSDA occurred in whom !5 mg/level of BMP was used (2/9) and no PSDA were seen when use was $5 mg/level (0/20) (p 5 0.01). 5 complications in Group I and 3 in II were observed. There were no BMP related complications such as heterotopic bone, seroma, infections, radiculitis or differences in cancers or tumors (BMP; acoustic neuroma (n51), ICBG; squamous cell carcinoma of the skin (n51) and uterine fibroids (n51). In Group I, mean ODI scores improved from 37.6 to 22.8 while in II, 37.1 to 19.0 (p!0.05). The post-op total SRS score was 3.5 in Group I and 4.0 in II (p50.09). CONCLUSIONS: Our data demonstrates a lower prevalence of PSDA associated with the use of BMP compared to ICBG. The rate of PSDA in Group II was 0% in those pts who had $5 mg/level. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2012.08.359
P86. Incidence and Morbidity of Concomitant Spine Fractures in Combat-Related Amputees Ronald A. Lehman, Jr., MD1, Adam Bevevino2, Daniel G. Kang, MD2, Theodora C. Dworak2, Scott M. Tintle, MD3, Benjamin K. Potter, MD4; 1 Potomac, MD, US; 2Bethesda, MD, US; 3Fairfax, VA, US; 4Walter Reed National Military Medical Center, Bethesda, MD, US BACKGROUND CONTEXT: High-energy blasts are the most frequent cause of combat related amputations in Operations Iraqi and Enduring Freedom (OIF/OEF). The non-discriminating effects of this mechanism, often results in both appendicular and axial skeletal injuries. This study sought to determine the incidence and consequence of associated spine fractures on patients with traumatic lower extremity amputation sustained during OIF/OEF. PURPOSE: Determine the incidence and associated morbidity of spine fractures in combat related amputees. STUDY DESIGN/SETTING: Retrospective case series. PATIENT SAMPLE: Active duty military members who sustained a spine fracture and combat related lower extremity amputation from 2003 through 2008. OUTCOME MEASURES: Incidence rates of specific injury patterns and patient outcome measures.
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METHODS: Data from 300 consecutive combat related lower extremity amputations was retrospectively reviewed and grouped. Group I consisted of amputees with associated spine fractures, and Group II consisted of amputees without spine fractures. The results of the two groups were compared with regard to initial presentation and final functional outcomes. RESULTS: A total of 226 patients sustained 300 lower extremity amputations. Twenty-nine of these patients had a spine fracture (13%). Group 1 had a higher Injury Severity Score (ISS) than Group 2 (30 vs. 19, p! 0.001). Group I patients were also more likely to be admitted to the ICU (86% vs 46%, p !0.001). Furthermore, Group I patients had a significantly higher rate of heterotopic ossification in their residual limbs (82% vs 55%, p!0.005). CONCLUSIONS: The incidence of spine fractures in combat related amputees is 13%. The results suggest combat related amputees with spine fractures are more likely to sustain severe injuries to other body systems, as indicated by the significantly higher ISS scores and rates of ICU admission. This group also had a significantly higher rate of heterotopic ossification (HO) formation, which may be attributable to the greater local and/or systemic injuries sustained by these patients. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2012.08.360
P87. Access-Related Complications in Anterior Lumbar Surgery Performed by Spinal Surgeons Nasir A. Quraishi, MD1, Matthias A. K€onig, MD2, Masood Shafafy, MBBS, FICS3, Bronek M. Boszczyk, MD3, Michael P. Grevitt, MD, FRCS1, Hossein Mehdian, FRCS4, John Webb, FRCS1; 1Queens Medical Centre, Nottingham, UK; 2Munich, Germany; 3Centre for Spinal Studies and Surgery, Nottingham, UK; 4Nottingham, England, UK BACKGROUND CONTEXT: Anterior lumbar surgery is a common procedure for anterior lumbar interbody fusion (ALIF) and artificial disc replacement (ADR). PURPOSE: Our aim was to study the exposure related complications for anterior lumbar spinal surgery performed by spinal surgeons. STUDY DESIGN/SETTING: A retrospective review was performed of 304 consecutive patients who underwent anterior lumbar spinal surgery over 10 years (2001-2010) at our institution. PATIENT SAMPLE: All patients undergoing anterior lumbar surgery were included, with the exception of patients having surgery for tumour resection/infection/trauma. OUTCOME MEASURES: Each patient’s records were reviewed for patients’ demographics, diagnosis, procedure, level(s) of surgery and complications related to access surgery. METHODS: Each patient’s records were reviewed for patients’ demographics, diagnosis, procedure, level(s) of surgery and complications related to access surgery. RESULTS: All patients underwent an anterior paramedian retroperitoneal approach from the left side. The mean age of patients was 43 years (10-73; 197 male, 107 female). Indications for surgery were degenerative disc disease (DDD, 252), degenerative spondylolisthesis (21), scoliosis (18), iatrogenic spondylolisthesis (7) and pseudoarthrosis (3). The procedures performed were single level surgery – L5/S1 (139), L4/5 (57); 2 levels – L4/5 and L5/S1 (72), L3/4 and L4/5 (4); 3 levels – L3/4, L4/5, L5/S1 (6); 4 levels – L2/3, L3/4, L4/5, L5/S1 (4). The operative procedures were ALIF þ/- posterior fusion (136), ADR (46), ADR/ALIF (11), 2 level ALIF (3), 3 level ALIF (2), 3 level ADR/ALIF/ALIF (1), 4 level ADR/ADR/ ALIF/ALIF (2). Complications (70/296, 23%) were venous injury (28 (9.5%), 17 requiring repair), arterial injury (5 (1.2%), 3 repaired, 2 thrombosis), incidental peritoneal opening (12 (4%)), leg oedema (2 (0.6%)), superficial infection (10 (3.4%)), deep infection (3 (1%)), retrograde ejaculation (0), and others (10 (3.4%)).
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
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Proceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 99S–165S
CONCLUSIONS: We report a very thorough and critical review of our anterior lumbar access surgeries performed mostly for DDD and spondylolisthesis at L4/5 and L5/S1 levels.Vascular problems (33/296, 11%) were the most common complication during this approach. In the majority, these were managed by the spinal surgeon without any sequelae. The incidence of major venous injury requiring repair was 17/296 (5.7%) and arterial thrombosis 2/296 (0.67%). Our results are comparable to other studies and support the notion that anterior access surgery to the lumbar spine can be performed safely by spinal surgeons. With adequate training, spinal surgeons are capable of performing this approach without direct vascular support, but they should be available if required. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
CONCLUSIONS: This large prospective global clinical study confirms the findings of a recent AOSpine North American study showing that surgical treatment for CSM is associated with significant improvements in generic and disease-specific outcome measures. The study also reveals significant variations in the extent of improvement across the world which may reflect differences in demographics, socio-cultural perceptions of health and disability and treatment protocols. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
http://dx.doi.org/10.1016/j.spinee.2012.08.361
P89. The Effects of Nimodipine and Nicotine on Diffusion into the Intervertebral Disc In Vivo Sarah E. Linley1, Josh Peterson2, Rosemarie Mastropolo, MD2, James P. Lawrence, MD, MBA3, Luciana Lopes, PhD4, Joseph Glennon, VMD5, Eric H. Ledet, PhD2; 1Easton, CT, US; 2Rensselaer Polytechnic Institute, Troy, NY, US; 3Capital Region Spine, Albany, NY, US; 4Albany, NY, US; 5 Capital District Veterinary Surgical Associates, New York, NY, US
P88. International Variations in the Clinical Presentation and Management of Cervical Spondylotic Myelopathy: One-Year Outcomes of the AOSpine Multicenter Prospective CSM-I Study Michael G. Fehlings, MD, PhD, FRCSC1, Branko Kopjar, MD, PhD2, Giuseppe Barbagallo, MD3, R.H.M. Bartels, MD4, Qiang Zhou5, Paul M. Arnold, MD6, Mehmet Zileli, MD7, Yasutsugu Yukawa, MD8, Osmar J. Moraes, MD9, Tomoaki Toyone, MD, PhD10, Masato Tanaka, MD11, Ciaran Bolger, FRCS, PhD12; 1Toronto Western Hospital, Toronto, ON, Canada; 2Mercer Island, WA, US; 3A.O.V. Policlinico, Catania, Italy; 4 Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 5 China; 6University of Kansas Medical Center Department Neurosurgery, Kansas City, KS, US; 7Izmir, Turkey; 8Nagoya University School of Medicine, Japan; 9Sao Paulo, Brazil; 10Teikyo University, Ichihara, Japan; 11 Okayama, Japan; 12Trinity College Dublin, Dublin, Ireland BACKGROUND CONTEXT: Recent studies conducted in North America have demonstrated benefits of surgical treatment for symptomatic CSM. However, differences in pathology, comorbidities, treatment approaches and cultural response to treatment may affect the generalizability of these findings at the global level. PURPOSE: To assess (i) the potential beneficial effects of surgery for CSM at a global level and (ii) whether the outcomes of surgical treatment for CSM vary according to region internationally. STUDY DESIGN/SETTING: Prospective, multi-center, cohort study involving sites in Europe, Asia, South America and North America. PATIENT SAMPLE: A total of 486 patients receiving surgery for clinically symptomatic CSM were enrolled in a prospective multicenter, cohort study which is continuing to accrue subjects at 16 sites in Europe, Asia, North and South America. OUTCOME MEASURES: Independent assessment of a series of generic and disease specific outcome measures including: modified Japanese Orthopaedic Assessment scale (mJOA), Nurick Score, Neck Disability Index (NDI), SF36v2. METHODS: Changes in outcomes at 12 months were analyzed using multivariate techniques (SAS 9.2 PROC MIXED) adjusting for baseline differences in patient populations (age, gender, surgical approach, number of spinal levels and baseline outcome parameter value). RESULTS: There were 35% females ; average age was 56.1 years (SD 12.4). Patients underwent anterior (58%), posterior (40%) or circumferential (2%) surgery. A total of 252 patients have completed the 12 month follow-up. At 12 months, all outcome variables improved significantly. The average improvements were as follows: mJOA 2.41 (SD 2.67, P !.01); NDI 11.89 (SD 20.05, P !.01); Nurick 1.31 (SD 1.4, P !.01); SF36v2 PCS 7.93 (SD 9.6, P !.01); SF36v2 MCS 7.06 (SD 10.27, P !.01). In a multivariate adjusted model, the amount of improvement varied significantly among the regions. Neurological outcomes (mJOA and Nurick) were better in North America and Asia Pacific compared to Latin America and Europe. SF36v2 PCS and MCS outcomes were better in Asia and Latin America than Europe.
http://dx.doi.org/10.1016/j.spinee.2012.08.362
BACKGROUND CONTEXT: The intervertebral disc (IVD) relies on trans-endplate small molecule transport for nutrition. Increases in subchondral bone density cause reduced diffusion and affect disc homeostatis. Enhancing diffusion is therefore a strategy to slow, prevent, or reverse disc degeneration. Diffusion initiates from the micro-vasculature of the vertebral endplate (EP) region. As such, pharmaceutical interventions which target subchondral micro-vessel density are attractive. The calcium channel antagonist nimodipine has been shown to increase EP vascularity. Conversely, nicotine has been linked with IVD degeneration and reduced EP vascularity. The long-term effects of these agents on diffusion into the IVD have not been quantified. PURPOSE: The purpose of this study was to characterize the effects of 8 week nimodipine and nicotine treatment on diffusion into the IVD of the New Zealand white (NZW) rabbit. STUDY DESIGN/SETTING: NZW rabbits were given daily treatments of either subcutaneous nimodipine or transdermal nicotine for 8 weeks. A control group received no drug treatments. Post-contrast enhanced MRI was used to quantify diffusion into the IVD and overall disc health, and mCT was used to quantify changes in subchondral bone density. Histology was used to quantify micro-vessel density. METHODS: Nine skeletally mature NZW rabbits were randomized into 3 groups of 3 animals each: nimodipine treatment, nicotine treatment, and a control group. Animals designated for the nimodipine treatment group received daily subcutaneous injections of nimodipine (0.5 mg/mL nimodipine in 90% Polyethylene glycol 400, 10% ethanol) for 8 weeks. Animals in the nicotine treatment group received 10.5 mg of daily transdermal nicotine for 8 weeks via a commercially available nicotine patch. At the conclusion of the 8 week treatment regimen, all animals were euthanized 10 minutes following intravenous administration of 0.3 mmols/kg gadodiamide. Spines were harvested and imaged using a 7 T MRI. T1 and T2 constants were measured in the disc, and mCT was used to measure endplate density. Histology was used to assess disc health and vessel density. RESULTS: Compared to controls, nimodipine treatment resulted in a 5.7% to 12.2% increase in diffusion into the IVD. T1 constants in the nicotine treatment group were not significantly different from controls. Subchondral bone density was not significantly different across all treatment groups. T2 constants in the nicotine group were decreased an average of 18.2% as compared to controls, while T2 constants were not significantly different between the nimodipine and control groups. CONCLUSIONS: Our results indicate that nicotine treatment did not cause a reduction in diffusion into the IVD, but the decreased T2 constant observed is suggestive of early stage degenerative changes. Nimodipine treatment was shown to increase diffusion into the healthy intervertebral disc independent of changes in bone density, which is likely a result of
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
P86. Incidence and Morbidity of Concomitant Spine Fractures in Combat-Related Amputees Ronald A. Lehman, Jr., MD1, Adam Bevevino2, Daniel G. Kang, MD2, Theodora C. Dworak2, Scott M. Tintle, MD3, Benjamin K. Potter, MD4; 1 Potomac, MD, US; 2Bethesda, MD, US; 3Fairfax, VA, US; 4Walter Reed National Military Medical Center, Bethesda, MD, US BACKGROUND CONTEXT: High-energy blasts are the most frequent cause of combat related amputations in Operations Iraqi and Enduring Freedom (OIF/OEF). The non-discriminating effects of this mechanism, often results in both appendicular and axial skeletal injuries. This study sought to determine the incidence and consequence of associated spine fractures on patients with traumatic lower extremity amputation sustained during OIF/OEF. PURPOSE: Determine the incidence and associated morbidity of spine fractures in combat related amputees. STUDY DESIGN/SETTING: Retrospective case series. PATIENT SAMPLE: Active duty military members who sustained a spine fracture and combat related lower extremity amputation from 2003 through 2008. OUTCOME MEASURES: Incidence rates of specific injury patterns and patient outcome measures.
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METHODS: Data from 300 consecutive combat related lower extremity amputations was retrospectively reviewed and grouped. Group I consisted of amputees with associated spine fractures, and Group II consisted of amputees without spine fractures. The results of the two groups were compared with regard to initial presentation and final functional outcomes. RESULTS: A total of 226 patients sustained 300 lower extremity amputations. Twenty-nine of these patients had a spine fracture (13%). Group 1 had a higher Injury Severity Score (ISS) than Group 2 (30 vs. 19, p! 0.001). Group I patients were also more likely to be admitted to the ICU (86% vs 46%, p !0.001). Furthermore, Group I patients had a significantly higher rate of heterotopic ossification in their residual limbs (82% vs 55%, p!0.005). CONCLUSIONS: The incidence of spine fractures in combat related amputees is 13%. The results suggest combat related amputees with spine fractures are more likely to sustain severe injuries to other body systems, as indicated by the significantly higher ISS scores and rates of ICU admission. This group also had a significantly higher rate of heterotopic ossification (HO) formation, which may be attributable to the greater local and/or systemic injuries sustained by these patients. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2012.08.360
P87. Access-Related Complications in Anterior Lumbar Surgery Performed by Spinal Surgeons Nasir A. Quraishi, MD1, Matthias A. K€onig, MD2, Masood Shafafy, MBBS, FICS3, Bronek M. Boszczyk, MD3, Michael P. Grevitt, MD, FRCS1, Hossein Mehdian, FRCS4, John Webb, FRCS1; 1Queens Medical Centre, Nottingham, UK; 2Munich, Germany; 3Centre for Spinal Studies and Surgery, Nottingham, UK; 4Nottingham, England, UK BACKGROUND CONTEXT: Anterior lumbar surgery is a common procedure for anterior lumbar interbody fusion (ALIF) and artificial disc replacement (ADR). PURPOSE: Our aim was to study the exposure related complications for anterior lumbar spinal surgery performed by spinal surgeons. STUDY DESIGN/SETTING: A retrospective review was performed of 304 consecutive patients who underwent anterior lumbar spinal surgery over 10 years (2001-2010) at our institution. PATIENT SAMPLE: All patients undergoing anterior lumbar surgery were included, with the exception of patients having surgery for tumour resection/infection/trauma. OUTCOME MEASURES: Each patient’s records were reviewed for patients’ demographics, diagnosis, procedure, level(s) of surgery and complications related to access surgery. METHODS: Each patient’s records were reviewed for patients’ demographics, diagnosis, procedure, level(s) of surgery and complications related to access surgery. RESULTS: All patients underwent an anterior paramedian retroperitoneal approach from the left side. The mean age of patients was 43 years (10-73; 197 male, 107 female). Indications for surgery were degenerative disc disease (DDD, 252), degenerative spondylolisthesis (21), scoliosis (18), iatrogenic spondylolisthesis (7) and pseudoarthrosis (3). The procedures performed were single level surgery – L5/S1 (139), L4/5 (57); 2 levels – L4/5 and L5/S1 (72), L3/4 and L4/5 (4); 3 levels – L3/4, L4/5, L5/S1 (6); 4 levels – L2/3, L3/4, L4/5, L5/S1 (4). The operative procedures were ALIF þ/- posterior fusion (136), ADR (46), ADR/ALIF (11), 2 level ALIF (3), 3 level ALIF (2), 3 level ADR/ALIF/ALIF (1), 4 level ADR/ADR/ ALIF/ALIF (2). Complications (70/296, 23%) were venous injury (28 (9.5%), 17 requiring repair), arterial injury (5 (1.2%), 3 repaired, 2 thrombosis), incidental peritoneal opening (12 (4%)), leg oedema (2 (0.6%)), superficial infection (10 (3.4%)), deep infection (3 (1%)), retrograde ejaculation (0), and others (10 (3.4%)).
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
138S
Proceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 99S–165S
CONCLUSIONS: We report a very thorough and critical review of our anterior lumbar access surgeries performed mostly for DDD and spondylolisthesis at L4/5 and L5/S1 levels.Vascular problems (33/296, 11%) were the most common complication during this approach. In the majority, these were managed by the spinal surgeon without any sequelae. The incidence of major venous injury requiring repair was 17/296 (5.7%) and arterial thrombosis 2/296 (0.67%). Our results are comparable to other studies and support the notion that anterior access surgery to the lumbar spine can be performed safely by spinal surgeons. With adequate training, spinal surgeons are capable of performing this approach without direct vascular support, but they should be available if required. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
CONCLUSIONS: This large prospective global clinical study confirms the findings of a recent AOSpine North American study showing that surgical treatment for CSM is associated with significant improvements in generic and disease-specific outcome measures. The study also reveals significant variations in the extent of improvement across the world which may reflect differences in demographics, socio-cultural perceptions of health and disability and treatment protocols. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
http://dx.doi.org/10.1016/j.spinee.2012.08.361
P89. The Effects of Nimodipine and Nicotine on Diffusion into the Intervertebral Disc In Vivo Sarah E. Linley1, Josh Peterson2, Rosemarie Mastropolo, MD2, James P. Lawrence, MD, MBA3, Luciana Lopes, PhD4, Joseph Glennon, VMD5, Eric H. Ledet, PhD2; 1Easton, CT, US; 2Rensselaer Polytechnic Institute, Troy, NY, US; 3Capital Region Spine, Albany, NY, US; 4Albany, NY, US; 5 Capital District Veterinary Surgical Associates, New York, NY, US
P88. International Variations in the Clinical Presentation and Management of Cervical Spondylotic Myelopathy: One-Year Outcomes of the AOSpine Multicenter Prospective CSM-I Study Michael G. Fehlings, MD, PhD, FRCSC1, Branko Kopjar, MD, PhD2, Giuseppe Barbagallo, MD3, R.H.M. Bartels, MD4, Qiang Zhou5, Paul M. Arnold, MD6, Mehmet Zileli, MD7, Yasutsugu Yukawa, MD8, Osmar J. Moraes, MD9, Tomoaki Toyone, MD, PhD10, Masato Tanaka, MD11, Ciaran Bolger, FRCS, PhD12; 1Toronto Western Hospital, Toronto, ON, Canada; 2Mercer Island, WA, US; 3A.O.V. Policlinico, Catania, Italy; 4 Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 5 China; 6University of Kansas Medical Center Department Neurosurgery, Kansas City, KS, US; 7Izmir, Turkey; 8Nagoya University School of Medicine, Japan; 9Sao Paulo, Brazil; 10Teikyo University, Ichihara, Japan; 11 Okayama, Japan; 12Trinity College Dublin, Dublin, Ireland BACKGROUND CONTEXT: Recent studies conducted in North America have demonstrated benefits of surgical treatment for symptomatic CSM. However, differences in pathology, comorbidities, treatment approaches and cultural response to treatment may affect the generalizability of these findings at the global level. PURPOSE: To assess (i) the potential beneficial effects of surgery for CSM at a global level and (ii) whether the outcomes of surgical treatment for CSM vary according to region internationally. STUDY DESIGN/SETTING: Prospective, multi-center, cohort study involving sites in Europe, Asia, South America and North America. PATIENT SAMPLE: A total of 486 patients receiving surgery for clinically symptomatic CSM were enrolled in a prospective multicenter, cohort study which is continuing to accrue subjects at 16 sites in Europe, Asia, North and South America. OUTCOME MEASURES: Independent assessment of a series of generic and disease specific outcome measures including: modified Japanese Orthopaedic Assessment scale (mJOA), Nurick Score, Neck Disability Index (NDI), SF36v2. METHODS: Changes in outcomes at 12 months were analyzed using multivariate techniques (SAS 9.2 PROC MIXED) adjusting for baseline differences in patient populations (age, gender, surgical approach, number of spinal levels and baseline outcome parameter value). RESULTS: There were 35% females ; average age was 56.1 years (SD 12.4). Patients underwent anterior (58%), posterior (40%) or circumferential (2%) surgery. A total of 252 patients have completed the 12 month follow-up. At 12 months, all outcome variables improved significantly. The average improvements were as follows: mJOA 2.41 (SD 2.67, P !.01); NDI 11.89 (SD 20.05, P !.01); Nurick 1.31 (SD 1.4, P !.01); SF36v2 PCS 7.93 (SD 9.6, P !.01); SF36v2 MCS 7.06 (SD 10.27, P !.01). In a multivariate adjusted model, the amount of improvement varied significantly among the regions. Neurological outcomes (mJOA and Nurick) were better in North America and Asia Pacific compared to Latin America and Europe. SF36v2 PCS and MCS outcomes were better in Asia and Latin America than Europe.
http://dx.doi.org/10.1016/j.spinee.2012.08.362
BACKGROUND CONTEXT: The intervertebral disc (IVD) relies on trans-endplate small molecule transport for nutrition. Increases in subchondral bone density cause reduced diffusion and affect disc homeostatis. Enhancing diffusion is therefore a strategy to slow, prevent, or reverse disc degeneration. Diffusion initiates from the micro-vasculature of the vertebral endplate (EP) region. As such, pharmaceutical interventions which target subchondral micro-vessel density are attractive. The calcium channel antagonist nimodipine has been shown to increase EP vascularity. Conversely, nicotine has been linked with IVD degeneration and reduced EP vascularity. The long-term effects of these agents on diffusion into the IVD have not been quantified. PURPOSE: The purpose of this study was to characterize the effects of 8 week nimodipine and nicotine treatment on diffusion into the IVD of the New Zealand white (NZW) rabbit. STUDY DESIGN/SETTING: NZW rabbits were given daily treatments of either subcutaneous nimodipine or transdermal nicotine for 8 weeks. A control group received no drug treatments. Post-contrast enhanced MRI was used to quantify diffusion into the IVD and overall disc health, and mCT was used to quantify changes in subchondral bone density. Histology was used to quantify micro-vessel density. METHODS: Nine skeletally mature NZW rabbits were randomized into 3 groups of 3 animals each: nimodipine treatment, nicotine treatment, and a control group. Animals designated for the nimodipine treatment group received daily subcutaneous injections of nimodipine (0.5 mg/mL nimodipine in 90% Polyethylene glycol 400, 10% ethanol) for 8 weeks. Animals in the nicotine treatment group received 10.5 mg of daily transdermal nicotine for 8 weeks via a commercially available nicotine patch. At the conclusion of the 8 week treatment regimen, all animals were euthanized 10 minutes following intravenous administration of 0.3 mmols/kg gadodiamide. Spines were harvested and imaged using a 7 T MRI. T1 and T2 constants were measured in the disc, and mCT was used to measure endplate density. Histology was used to assess disc health and vessel density. RESULTS: Compared to controls, nimodipine treatment resulted in a 5.7% to 12.2% increase in diffusion into the IVD. T1 constants in the nicotine treatment group were not significantly different from controls. Subchondral bone density was not significantly different across all treatment groups. T2 constants in the nicotine group were decreased an average of 18.2% as compared to controls, while T2 constants were not significantly different between the nimodipine and control groups. CONCLUSIONS: Our results indicate that nicotine treatment did not cause a reduction in diffusion into the IVD, but the decreased T2 constant observed is suggestive of early stage degenerative changes. Nimodipine treatment was shown to increase diffusion into the healthy intervertebral disc independent of changes in bone density, which is likely a result of
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.