- Email: [email protected]
Timing of surgical staging in adult spinal deformity surgery: is later better?
The Spine Journal 13 (2013) 1723–1725
Commentary
Timing of surgical staging in adult spinal deformity surgery: is later better? Adam L. Wollowick, MDa, Daniel G. Kang, MDb, Ronald A. Lehman, Jr., MDb,c,* a Department of Orthopaedic Surgery, Albert Einstein College of Medicine, 3400 Bainbridge Avenue, Bronx, NY 10461, USA Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Building #19, Bethesda, MD 20889, USA c Division of Orthopaedics, Department of Surgery, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20889, USA
b
Received 8 June 2013; revised 21 August 2013; accepted 19 September 2013
COMMENTARY ON: Hassanzadeh H, Gjolaj JP, El Dafrawy MH, et al. The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery. Spine J 2013;13:1717–22 (in this issue).
Optimizing clinical outcomes and reducing complications after adult spinal deformity surgery remain important topics, and we commend the authors of ‘‘The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery’’ [1]. They compared the outcome of 63 consecutive adult spinal deformity patients older than 40 years with a minimum 2-year follow-up, who underwent staged posterior spinal fusion surgery followed by anterior lumbar interbody fusion (ALIF) operations either !21 days (early) or $21 days (late) apart. The authors concluded that patients who had the second stage performed later ($21 days) experienced significantly better functional outcomes and lower allogeneic blood transfusion rates than those patients treated within 21 days. Although the authors raise several interesting points, the study is limited by its retrospective design of a single-surgeon/institution experience with a small,
FDA device/drug status: Not applicable. Author disclosures: ALW: Consulting: Depuy Spine, Stryker Spine; Research Support (Investigator Salary, Staff/Materials): Stryker Spine (D). DGK: Nothing to disclose. RAL: Grants: DARPA (I), CDMRP (H). The disclosure key can be found on the Table of Contents and at www. TheSpineJournalOnline.com. The views expressed in this manuscript are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or US government. Two authors are employees of the US government. This work was prepared as part of their official duties, and as such, there is no copyright to be transferred. * Corresponding author. Department of Orthopaedic Surgery and Rehabilitation, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Building 19, Room #2101, Bethesda, MD 20889, USA. Tel.: (301) 319-4818; fax: (301) 319-2361. E-mail address: [email protected] (R.A. Lehman) 1529-9430/$ - see front matter Published by Elsevier Inc. http://dx.doi.org/10.1016/j.spinee.2013.09.023
heterogeneous patient sample. Therefore, a definitive answer to the question ‘‘Is later better?’’ remains elusive. During the past several decades, there have been substantial advancements in perioperative medical management. Despite improvements in anesthetic and surgical techniques, complications continue to occur with considerable frequency and remain a significant concern in adult spinal deformity surgery. Glassman et al. previously demonstrated that major complications following adult spinal deformity surgery resulted in a significant deterioration in healthrelated quality of life outcomes compared with patients with no or minor complications [2]. Therefore, minimizing complications to optimize outcomes should be at the forefront of the surgeon’s decision-making and planning. Several prior studies have identified factors that may increase complications rates such as advanced age, medical comorbidities, cigarette smoking, and poor bone quality [2–4]. Although these patient parameters are outside the surgeon’s direct control, every effort and strategy should be applied to mitigate the risk of complications including medical optimization, smoking cessation, nutritional support, and pharmacologic treatment of osteoporosis [2–5]. On the other hand, the spine deformity surgeon may directly influence the patient’s clinical outcome and lower the risk of complications by performing comprehensive preoperative planning and using meticulous surgical technique [3,6]. There are many important decisions facing the adult deformity surgeon, including the number of levels/extent of fusion (ie, L5 vs. sacrum) [7,8], the need for spinal column osteotomies [9], the extent of deformity correction, and the need for restoration of sagittal balance [4]. All these must be performed while simultaneously avoiding neurologic compromise. Additionally, the surgeon needs to decide
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if a posterior-based procedure or a combined anterior/posterior procedure is to be completed in a single-day (1-stage) or staged (2-stage) operation. Circumferential anterior and posterior spinal fusion, compared with posterior fusion alone, has demonstrated greater curve correction, decreased pseudarthrosis rates, decreased incidence of fixed sagittal deformities, and the ability to spare motion segments [5,8,10–12]. However, significant controversy remains as there have been numerous studies, mostly small and retrospective in nature, comparing single-day versus staged operations for spinal deformity that have generated conflicting data on outcomes and complication rates [5,13–18]. Some surgeons encourage single-day combined procedures because of the potential for decreasing complications, avoiding multiple anesthetic inductions, and prolonging therapy and recovery. Interestingly, Dick et al. found that patients undergoing the procedure in one stage reduced the hospital stay by an average of 7 days and the total hospital bill by 30%, resulting in greater patient satisfaction [5]. Reducing hospital costs is an important consideration and is playing a larger role in surgical-decision making because of the modern economic environment, which emphasizes cost containment by insurance carriers and government agencies [5]. Although the present study by Hassanzadeh et al. does not evaluate the economic costs of further delaying the second-staged procedure, this is another critical component of answering the question ‘‘is later better?’’ and should be an integral component of future studies evaluating this topic. Although, by convention, most surgeons who advocate staged procedures wait from 1 to 3 weeks between operations [5], the present study by Hassanzadeh et al. is the first to evaluate the impact of the timing of the second stage on clinical outcomes. Of note, the authors included three patients who underwent ‘‘continuous’’ anterior and posterior procedures on the same day. This choice seems curious because the purpose of the study was to analyze short versus long duration between stages and continuous surgery, by definition, does not involve stages. A further point of concern with the present study was the definition of early versus late, which was arbitrarily determined by the senior author. The authors attempt to validate their argument for delaying staged surgery more than 21 days by citing two studies that found that hematopoiesis requires several weeks to occur following a 500 mL phlebotomy, with return to baseline hemoglobin on average after 49.6 days in one study and 40 days in the other [19,20]. Therefore, the patients in the present study would have been unlikely to return to baseline hemoglobin levels within 21 days even with iron supplementation. Also, average blood loss was closer to 4 L in both groups, much greater than the 500 mL phlebotomy from the previous studies. The physiologic stress and the metabolic recovery of a major spinal surgery should also not be compared with a phlebotomy procedure. Therefore, the significance of staging patients based on a 21-day cutoff is called into question. The duration of time between
stages may need to be longer based on the authors presumption that patients may better tolerate second-stage surgery if they are able to return to baseline hemoglobin levels. The second point of concern is that while the authors found no significant difference in average total estimated blood loss, there was a statistically significant lower total perioperative packed red blood cell transfusion rate for the late ($21 day) group (6.8 vs. 8.8 units). The authors do not describe an established protocol to trigger transfusion, which is truly necessary to make a comparison of this outcome measure between the groups as some patients could have more liberally received blood transfusion. Furthermore, the authors did not provide the average preoperative hemoglobin of each group, which is also important because lower preoperative hemoglobin could have biased one group to be at higher risk for blood transfusion requirement [21,22]. The study was also limited by the small heterogeneous patient sample from a single surgeon/institution experience, and unlike other studies in the literature regarding staged circumferential fusions, the authors performed posterior spinal fusion before the staged anterior procedure. The authors cite high rate of pseudarthrosis (up to 20%) at the lumbosacral junction following long posterior fusion constructs to the sacrum as the indication to perform ALIFs in the study patients. Unlike most other similar studies in the literature, anterior surgery in this study was not performed for deformity correction or to address stiff curves. The authors performed deformity correction for a variety of diagnoses, including sagittal, coronal, and combined deformity, and more specific diagnoses were not provided. It is difficult to draw conclusions about the results of the study without being able to directly compare differences in staging patients with the same diagnosis, not a general clinical indicator. Also, in each group, there are tremendous variations in the number of levels fused posteriorly, number of ALIFs performed, as well as the type and number of spinal column osteotomies. A patient undergoing a four-level posterior surgery followed by a single-level ALIF is likely to have different results than a patient undergoing a 16-level posterior fusion with three column osteotomy and a multilevel anterior procedure. These types of patients were placed in similar groups with the only distinction being the time between stages; therefore, only general conclusions can be drawn. Another important, and final point of, concern is the title of the study, which states that the timing of staging has a ‘‘.Significant impact on the complications and functional outcomes.’’ This may be misleading as the results demonstrated no significant differences between the early versus late group in terms of minor and major complications. Summary As a result of the concerns raised previously, this study is unlikely to have a large clinical impact or to alter
A.L. Wollowick et al. / The Spine Journal 13 (2013) 1723–1725
treatment strategies used by spinal deformity surgeons. Certainly, this study raises important questions about how to maximize the safety and efficacy of complex spinal reconstructions in adult patients. However, the study would have benefited from a more detailed analysis that examines specific procedures and correlates the measured parameters to each of them. It is worth pursuing the basic premise of this study, but this will in all likelihood require a multicenter contribution to provide sufficient power. Furthermore, a prospective study design would strengthen the weight of any conclusions drawn from such a study. The authors are again commended for undertaking a study addressing a complicated issue about which few studies exist in the current literature. More than anything else, this article shines a light on an area that requires additional, more structured study. References [1] Hassanzadeh H, Gjolaj JP, El Dafrawy MH, et al. The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery. Spine J 2013;13: 1717–22. [2] Glassman SD, Hamill CL, Bridwell KH, et al. The impact of perioperative complications on clinical outcome in adult deformity surgery. Spine 2007;32:2764–70. [3] Baron EM, Albert TJ. Medical complications of surgical treatment of adult spinal deformity and how to avoid them. Spine 2006;31 (19 Suppl):S106–18. [4] Bradford DS, Tay BK, Hu SS. Adult scoliosis: surgical indications, operative management, complications, and outcomes. Spine 1999;24: 2617–29. [5] Dick J, Boachie-Adjei O, Wilson M. One-stage versus two-stage anterior and posterior spinal reconstruction in adults. Comparison of outcomes including nutritional status, complications rates, hospital costs, and other factors. Spine 1992;17(8 Suppl):S310–6. [6] Hu SS, Berven SH. Preparing the adult deformity patient for spinal surgery. Spine 2006;31(19 Suppl):S126–31. [7] Edwards CC 2nd, Bridwell KH, Patel A, et al. Long adult deformity fusions to L5 and the sacrum. A matched cohort analysis. Spine 2004;29:1996–2005.
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[8] Kostuik JP, Hall BB. Spinal fusions to the sacrum in adults with scoliosis. Spine 1983;8:489–500. [9] Bridwell KH, Lewis SJ, Edwards C, et al. Complications and outcomes of pedicle subtraction osteotomies for fixed sagittal imbalance. Spine 2003;28:2093–101. [10] Boachie-Adjei O, Dendrinos GK, Ogilvie JW, et al. Management of adult spinal deformity with combined anterior-posterior arthrodesis and Luque-Galveston instrumentation. J Spinal Disord 1991;4: 131–41. [11] Byrd JA 3rd, Scoles PV, Winter RB, et al. Adult idiopathic scoliosis treated by anterior and posterior spinal fusion. J Bone Joint Surg Am 1987;69:843–50. [12] Swank S, Lonstein JE, Moe JH, et al. Surgical treatment of adult scoliosis. A review of two hundred and twenty-two cases. J Bone Joint Surg Am 1981;63:268–87. [13] Passias PG, Ma Y, Chiu YL, et al. Comparative safety of simultaneous and staged anterior and posterior spinal surgery. Spine 2012;37:247–55. [14] Powell ET, Krengel WF 3rd, King HA, et al. Comparison of sameday sequential anterior and posterior spinal fusion with delayed two-stage anterior and posterior spinal fusion. Spine 1994;19: 1256–9. [15] Rhee JM, Bridwell KH, Lenke LG, et al. Staged posterior surgery for severe adult spinal deformity. Spine 2003;28:2116–21. [16] Shen J, Qiu G, Wang Y, et al. Comparison of 1-stage versus 2-stage anterior and posterior spinal fusion for severe and rigid idiopathic scoliosis—a randomized prospective study. Spine 2006;31: 2525–8. [17] Shufflebarger HL, Grimm JO, Bui V, et al. Anterior and posterior spinal fusion. Staged versus same-day surgery. Spine 1991;16:930–3. [18] Wright N. Single-surgeon simultaneous versus staged anterior and posterior spinal reconstruction: a comparative study. J Spinal Disord Tech 2005;18(Suppl):S48–57. [19] Coleman DH, Stevens AR Jr, Dodge HT, et al. Rate of blood regeneration after blood loss. AMA Arch Intern Med 1953;92:341–9. [20] Fowler WM, Barer AP. Rate of hemoglobin regeneration in blood donors. JAMA 1942;118:421–7. [21] Feagan BG, Wong CJ, Johnston WC, et al. Transfusion practices for elective orthopedic surgery. CMAJ 2002;166:310–4. [22] Elgafy H, Bransford RJ, McGuire RA, et al. Blood loss in major spine surgery: are there effective measures to decrease massive hemorrhage in major spine fusion surgery? Spine 2010;35(9 Suppl): S47–56.
Commentary
Timing of surgical staging in adult spinal deformity surgery: is later better? Adam L. Wollowick, MDa, Daniel G. Kang, MDb, Ronald A. Lehman, Jr., MDb,c,* a Department of Orthopaedic Surgery, Albert Einstein College of Medicine, 3400 Bainbridge Avenue, Bronx, NY 10461, USA Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Building #19, Bethesda, MD 20889, USA c Division of Orthopaedics, Department of Surgery, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20889, USA
b
Received 8 June 2013; revised 21 August 2013; accepted 19 September 2013
COMMENTARY ON: Hassanzadeh H, Gjolaj JP, El Dafrawy MH, et al. The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery. Spine J 2013;13:1717–22 (in this issue).
Optimizing clinical outcomes and reducing complications after adult spinal deformity surgery remain important topics, and we commend the authors of ‘‘The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery’’ [1]. They compared the outcome of 63 consecutive adult spinal deformity patients older than 40 years with a minimum 2-year follow-up, who underwent staged posterior spinal fusion surgery followed by anterior lumbar interbody fusion (ALIF) operations either !21 days (early) or $21 days (late) apart. The authors concluded that patients who had the second stage performed later ($21 days) experienced significantly better functional outcomes and lower allogeneic blood transfusion rates than those patients treated within 21 days. Although the authors raise several interesting points, the study is limited by its retrospective design of a single-surgeon/institution experience with a small,
FDA device/drug status: Not applicable. Author disclosures: ALW: Consulting: Depuy Spine, Stryker Spine; Research Support (Investigator Salary, Staff/Materials): Stryker Spine (D). DGK: Nothing to disclose. RAL: Grants: DARPA (I), CDMRP (H). The disclosure key can be found on the Table of Contents and at www. TheSpineJournalOnline.com. The views expressed in this manuscript are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or US government. Two authors are employees of the US government. This work was prepared as part of their official duties, and as such, there is no copyright to be transferred. * Corresponding author. Department of Orthopaedic Surgery and Rehabilitation, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Building 19, Room #2101, Bethesda, MD 20889, USA. Tel.: (301) 319-4818; fax: (301) 319-2361. E-mail address: [email protected] (R.A. Lehman) 1529-9430/$ - see front matter Published by Elsevier Inc. http://dx.doi.org/10.1016/j.spinee.2013.09.023
heterogeneous patient sample. Therefore, a definitive answer to the question ‘‘Is later better?’’ remains elusive. During the past several decades, there have been substantial advancements in perioperative medical management. Despite improvements in anesthetic and surgical techniques, complications continue to occur with considerable frequency and remain a significant concern in adult spinal deformity surgery. Glassman et al. previously demonstrated that major complications following adult spinal deformity surgery resulted in a significant deterioration in healthrelated quality of life outcomes compared with patients with no or minor complications [2]. Therefore, minimizing complications to optimize outcomes should be at the forefront of the surgeon’s decision-making and planning. Several prior studies have identified factors that may increase complications rates such as advanced age, medical comorbidities, cigarette smoking, and poor bone quality [2–4]. Although these patient parameters are outside the surgeon’s direct control, every effort and strategy should be applied to mitigate the risk of complications including medical optimization, smoking cessation, nutritional support, and pharmacologic treatment of osteoporosis [2–5]. On the other hand, the spine deformity surgeon may directly influence the patient’s clinical outcome and lower the risk of complications by performing comprehensive preoperative planning and using meticulous surgical technique [3,6]. There are many important decisions facing the adult deformity surgeon, including the number of levels/extent of fusion (ie, L5 vs. sacrum) [7,8], the need for spinal column osteotomies [9], the extent of deformity correction, and the need for restoration of sagittal balance [4]. All these must be performed while simultaneously avoiding neurologic compromise. Additionally, the surgeon needs to decide
1724
A.L. Wollowick et al. / The Spine Journal 13 (2013) 1723–1725
if a posterior-based procedure or a combined anterior/posterior procedure is to be completed in a single-day (1-stage) or staged (2-stage) operation. Circumferential anterior and posterior spinal fusion, compared with posterior fusion alone, has demonstrated greater curve correction, decreased pseudarthrosis rates, decreased incidence of fixed sagittal deformities, and the ability to spare motion segments [5,8,10–12]. However, significant controversy remains as there have been numerous studies, mostly small and retrospective in nature, comparing single-day versus staged operations for spinal deformity that have generated conflicting data on outcomes and complication rates [5,13–18]. Some surgeons encourage single-day combined procedures because of the potential for decreasing complications, avoiding multiple anesthetic inductions, and prolonging therapy and recovery. Interestingly, Dick et al. found that patients undergoing the procedure in one stage reduced the hospital stay by an average of 7 days and the total hospital bill by 30%, resulting in greater patient satisfaction [5]. Reducing hospital costs is an important consideration and is playing a larger role in surgical-decision making because of the modern economic environment, which emphasizes cost containment by insurance carriers and government agencies [5]. Although the present study by Hassanzadeh et al. does not evaluate the economic costs of further delaying the second-staged procedure, this is another critical component of answering the question ‘‘is later better?’’ and should be an integral component of future studies evaluating this topic. Although, by convention, most surgeons who advocate staged procedures wait from 1 to 3 weeks between operations [5], the present study by Hassanzadeh et al. is the first to evaluate the impact of the timing of the second stage on clinical outcomes. Of note, the authors included three patients who underwent ‘‘continuous’’ anterior and posterior procedures on the same day. This choice seems curious because the purpose of the study was to analyze short versus long duration between stages and continuous surgery, by definition, does not involve stages. A further point of concern with the present study was the definition of early versus late, which was arbitrarily determined by the senior author. The authors attempt to validate their argument for delaying staged surgery more than 21 days by citing two studies that found that hematopoiesis requires several weeks to occur following a 500 mL phlebotomy, with return to baseline hemoglobin on average after 49.6 days in one study and 40 days in the other [19,20]. Therefore, the patients in the present study would have been unlikely to return to baseline hemoglobin levels within 21 days even with iron supplementation. Also, average blood loss was closer to 4 L in both groups, much greater than the 500 mL phlebotomy from the previous studies. The physiologic stress and the metabolic recovery of a major spinal surgery should also not be compared with a phlebotomy procedure. Therefore, the significance of staging patients based on a 21-day cutoff is called into question. The duration of time between
stages may need to be longer based on the authors presumption that patients may better tolerate second-stage surgery if they are able to return to baseline hemoglobin levels. The second point of concern is that while the authors found no significant difference in average total estimated blood loss, there was a statistically significant lower total perioperative packed red blood cell transfusion rate for the late ($21 day) group (6.8 vs. 8.8 units). The authors do not describe an established protocol to trigger transfusion, which is truly necessary to make a comparison of this outcome measure between the groups as some patients could have more liberally received blood transfusion. Furthermore, the authors did not provide the average preoperative hemoglobin of each group, which is also important because lower preoperative hemoglobin could have biased one group to be at higher risk for blood transfusion requirement [21,22]. The study was also limited by the small heterogeneous patient sample from a single surgeon/institution experience, and unlike other studies in the literature regarding staged circumferential fusions, the authors performed posterior spinal fusion before the staged anterior procedure. The authors cite high rate of pseudarthrosis (up to 20%) at the lumbosacral junction following long posterior fusion constructs to the sacrum as the indication to perform ALIFs in the study patients. Unlike most other similar studies in the literature, anterior surgery in this study was not performed for deformity correction or to address stiff curves. The authors performed deformity correction for a variety of diagnoses, including sagittal, coronal, and combined deformity, and more specific diagnoses were not provided. It is difficult to draw conclusions about the results of the study without being able to directly compare differences in staging patients with the same diagnosis, not a general clinical indicator. Also, in each group, there are tremendous variations in the number of levels fused posteriorly, number of ALIFs performed, as well as the type and number of spinal column osteotomies. A patient undergoing a four-level posterior surgery followed by a single-level ALIF is likely to have different results than a patient undergoing a 16-level posterior fusion with three column osteotomy and a multilevel anterior procedure. These types of patients were placed in similar groups with the only distinction being the time between stages; therefore, only general conclusions can be drawn. Another important, and final point of, concern is the title of the study, which states that the timing of staging has a ‘‘.Significant impact on the complications and functional outcomes.’’ This may be misleading as the results demonstrated no significant differences between the early versus late group in terms of minor and major complications. Summary As a result of the concerns raised previously, this study is unlikely to have a large clinical impact or to alter
A.L. Wollowick et al. / The Spine Journal 13 (2013) 1723–1725
treatment strategies used by spinal deformity surgeons. Certainly, this study raises important questions about how to maximize the safety and efficacy of complex spinal reconstructions in adult patients. However, the study would have benefited from a more detailed analysis that examines specific procedures and correlates the measured parameters to each of them. It is worth pursuing the basic premise of this study, but this will in all likelihood require a multicenter contribution to provide sufficient power. Furthermore, a prospective study design would strengthen the weight of any conclusions drawn from such a study. The authors are again commended for undertaking a study addressing a complicated issue about which few studies exist in the current literature. More than anything else, this article shines a light on an area that requires additional, more structured study. References [1] Hassanzadeh H, Gjolaj JP, El Dafrawy MH, et al. The timing of surgical staging has a significant impact on the complications and functional outcomes of adult spinal deformity surgery. Spine J 2013;13: 1717–22. [2] Glassman SD, Hamill CL, Bridwell KH, et al. The impact of perioperative complications on clinical outcome in adult deformity surgery. Spine 2007;32:2764–70. [3] Baron EM, Albert TJ. Medical complications of surgical treatment of adult spinal deformity and how to avoid them. Spine 2006;31 (19 Suppl):S106–18. [4] Bradford DS, Tay BK, Hu SS. Adult scoliosis: surgical indications, operative management, complications, and outcomes. Spine 1999;24: 2617–29. [5] Dick J, Boachie-Adjei O, Wilson M. One-stage versus two-stage anterior and posterior spinal reconstruction in adults. Comparison of outcomes including nutritional status, complications rates, hospital costs, and other factors. Spine 1992;17(8 Suppl):S310–6. [6] Hu SS, Berven SH. Preparing the adult deformity patient for spinal surgery. Spine 2006;31(19 Suppl):S126–31. [7] Edwards CC 2nd, Bridwell KH, Patel A, et al. Long adult deformity fusions to L5 and the sacrum. A matched cohort analysis. Spine 2004;29:1996–2005.
1725
[8] Kostuik JP, Hall BB. Spinal fusions to the sacrum in adults with scoliosis. Spine 1983;8:489–500. [9] Bridwell KH, Lewis SJ, Edwards C, et al. Complications and outcomes of pedicle subtraction osteotomies for fixed sagittal imbalance. Spine 2003;28:2093–101. [10] Boachie-Adjei O, Dendrinos GK, Ogilvie JW, et al. Management of adult spinal deformity with combined anterior-posterior arthrodesis and Luque-Galveston instrumentation. J Spinal Disord 1991;4: 131–41. [11] Byrd JA 3rd, Scoles PV, Winter RB, et al. Adult idiopathic scoliosis treated by anterior and posterior spinal fusion. J Bone Joint Surg Am 1987;69:843–50. [12] Swank S, Lonstein JE, Moe JH, et al. Surgical treatment of adult scoliosis. A review of two hundred and twenty-two cases. J Bone Joint Surg Am 1981;63:268–87. [13] Passias PG, Ma Y, Chiu YL, et al. Comparative safety of simultaneous and staged anterior and posterior spinal surgery. Spine 2012;37:247–55. [14] Powell ET, Krengel WF 3rd, King HA, et al. Comparison of sameday sequential anterior and posterior spinal fusion with delayed two-stage anterior and posterior spinal fusion. Spine 1994;19: 1256–9. [15] Rhee JM, Bridwell KH, Lenke LG, et al. Staged posterior surgery for severe adult spinal deformity. Spine 2003;28:2116–21. [16] Shen J, Qiu G, Wang Y, et al. Comparison of 1-stage versus 2-stage anterior and posterior spinal fusion for severe and rigid idiopathic scoliosis—a randomized prospective study. Spine 2006;31: 2525–8. [17] Shufflebarger HL, Grimm JO, Bui V, et al. Anterior and posterior spinal fusion. Staged versus same-day surgery. Spine 1991;16:930–3. [18] Wright N. Single-surgeon simultaneous versus staged anterior and posterior spinal reconstruction: a comparative study. J Spinal Disord Tech 2005;18(Suppl):S48–57. [19] Coleman DH, Stevens AR Jr, Dodge HT, et al. Rate of blood regeneration after blood loss. AMA Arch Intern Med 1953;92:341–9. [20] Fowler WM, Barer AP. Rate of hemoglobin regeneration in blood donors. JAMA 1942;118:421–7. [21] Feagan BG, Wong CJ, Johnston WC, et al. Transfusion practices for elective orthopedic surgery. CMAJ 2002;166:310–4. [22] Elgafy H, Bransford RJ, McGuire RA, et al. Blood loss in major spine surgery: are there effective measures to decrease massive hemorrhage in major spine fusion surgery? Spine 2010;35(9 Suppl): S47–56.