The indications for surgical intervention in patients with idiopathic scoliosis have been well defined. The goals of surgery are to achieve fusion and arrest progressive curvature while restoring normal coronal and sagittal balance. As first introduced by Harrington, posterior fusion, the gold standard of treatment, has a proven record of success. More recently, anterior techniques for performing fusion procedures via either a thoracotomy or a retroperitoneal approach have been popularized in attempts to achieve better correction of curvature, preserve motion segments, and avoid some of the complications of posterior fusion such as the development of the flat-back syndrome. Anterior instrumentation alone, although effective, can be kyphogenic and has been shown to be associated with complications such as pseudarthrosis and instrumentation failure. Performing a combined approach in patients with scoliosis and other deformities has become an increasingly popular procedure to achieve superior correction of deformity and to minimize later complications. Indications for a combined approach (usually consisting of anterior release, arthrodesis with or without use of instrumentation, and posterior segmental fusion) include: prevention of crankshaft phenomenon in juvenile or skeletally immature adolescents; correction of large curves (75°) or excessively rigid curves in skeletally mature or immature patients; correction of curves with large sagittal-plane deformities such as thoracic kyphosis (> 90°) or thoracic lordosis (> 20°); and correction of thoracolumbar curves that need to be fused to the sacrum. Surgery may be performed either in a staged proceedure or, more commonly, in a single sitting. The authors discuss techniques for combined surgery and complication avoidance.
Michael J. Rauzzino, Christopher I. Shaffrey, James Wagner, Russ Nockels and Mark Abel
Adam S. Kanter, Christopher I. Shaffrey, Praveen Mummaneni, Michael Y. Wang and Juan S. Uribe
Michael J. Rauzzino, Christopher I. Shaffrey, Russ P. Nockels, Gregory C. Wiggins, Jack Rock and James Wagner
The authors report their experience with 42 patients in whom anterior lumbar fusion was performed using titanium cages as a versatile adjunct to treat a wide variety of spinal deformity and pathological conditions. These conditions included congenital, degenerative, iatrogenic, infectious, traumatic, and malignant disorders of the thoracolumbar spine. Fusion rates and complications are compared with data previously reported in the literature.
Between July 1996 and July 1999 the senior authors (C.I.S., R.P.N., and M.J.R.) treated 42 patients by means of a transabdominal extraperitoneal (13 cases) or an anterolateral extraperitoneal approach (29 cases), 51 vertebral levels were fused using titanium cages packed with autologous bone. All vertebrectomies (27 cases) were reconstructed using a Miami Moss titanium mesh cage and Kaneda instrumentation. Interbody fusion (15 cases) was performed with either the BAK titanium threaded interbody cage (in 13 patients) or a Miami Moss titanium mesh cage (in two patients). The average follow-up period was 14.3 months. Seventeen patients had sustained a thoracolumbar burst fracture, 12 patients presented with degenerative spinal disorders, six with metastatic tumor, four with spinal deformity (one congenital and three iatrogenic), and three patients presented with spinal infections. In five patients anterior lumbar interbody fusion (ALIF) was supplemented with posterior segmental fixation at the time of the initial procedure. Of the 51 vertebral levels treated, solid arthrodesis was achieved in 49, a 96% fusion rate. One case of pseudarthrosis occurred in the group treated with BAK cages; the diagnosis was made based on the patient's continued mechanical back pain after undergoing L4–5 ALIF. The patient was treated with supplemental posterior fixation, and successful fusion occurred uneventfully with resolution of her back pain. In the group in which vertebrectomy was performed there was one case of fusion failure in a patient with metastatic breast cancer who had undergone an L-3 corpectomy with placement of a mesh cage. Although her back pain was immediately resolved, she died of systemic disease 3 months after surgery and before fusion could occur.
Complications related to the anterior approach included two vascular injuries (two left common iliac vein lacerations); one injury to the sympathetic plexus; one case of superficial phlebitis; two cases of prolonged ileus (greater than 48 hours postoperatively); one anterior femoral cutaneous nerve palsy; and one superficial wound infection. No deaths were directly related to the surgical procedure. There were no cases of dural laceration and no nerve root injury. There were no cases of deep venous thrombosis, pulmonary embolus, retrograde ejaculation, abdominal hernia, bowel or ureteral injury, or deep wound infection. Fusion-related complications included an iliac crest hematoma and prolonged donor-site pain in one patient. There were no complications related to placement or migration of the cages, but there was one case of screw fracture of the Kaneda device that did not require revision.
The authors conclude that anterior lumbar fusion performed using titanium interbody or mesh cages, packed with autologous bone, is an effective, safe method to achieve fusion in a wide variety of pathological conditions of the thoracolumbar spine. The fusion rate of 96% compares favorably with results reported in the literature. The complication rate mirrors the low morbidity rate associated with the anterior approach. A detailed study of clinical outcomes is in progress. Patient selection and strategies for avoiding complication are discussed.
Gregory C. Wiggins, Michael J. Rauzzino, Christopher I. Shaffrey, Russ P. Nockels, Richard Whitehill, Mark E. Shaffrey, James Wagner and Tord D. Alden
This study was conducted to determine the safety, efficacy, and complication rate associated with the anterior approach in the use of a new titanium mesh interbody fusion cage for the treatment of unstable thoracolumbar burst fractures. The experience with this technique is compared with the senior authors' (C.S., R.W., and M.S.) previously published results in the management of patients with unstable thoracolumbar burst fractures.
Between 1996 and 1999, 21 patients with unstable thoracolumbar (T12-L3) burst fractures underwent an anterolateral decompressive procedure in which a titanium cage and Kaneda device were used. Eleven of the 21 patients had sustained a neurological deficit, and all patients improved at least one Frankel grade (average 1.2 grades). There was improvement in outcome in terms of blood loss, correction of kyphosis, and pain, as measured on the Denis Pain and Work Scale, in our current group of patients treated via an anterior approach when compared with the results in those who underwent a posterior approach.
In our current study the anterior approach was demonstrated to be a safe and effective technique for the management of unstable thoracolumbar burst fractures. It offers superior results compared with the posterior approach. The addition of the new titanium mesh interbody cage to our previous anterior technique allows the patient's own bone to be harvested from the corpectomy site and used as a substrate for fusion, thereby obviating the need for iliac crest harvest. The use of the cage in association with the Kaneda device allows for improved correction of kyphosis and restoration of normal sagittal alignment in addition to improved functional outcomes.
Michael P. Kelly, Lawrence G. Lenke, Christopher I. Shaffrey, Christopher P. Ames, Leah Y. Carreon, Virginie Lafage, Justin S. Smith and Adam L. Shimer
The goal in this study was to evaluate the risk factors for complications, including new neurological deficits, in the largest cohort of patients with adult spinal deformity to date.
The Scoli-RISK-1 inclusion criteria were used to identify eligible patients from 5 centers who were treated between June 1, 2009, and June 1, 2011. Records were reviewed for patient demographic information, surgical data, and reports of perioperative complications. Neurological deficits were recorded as preexisting or as new deficits. Patients who underwent 3-column osteotomies (3COs) were compared with those who did not (posterior spinal fusion [PSF]). Between-group comparisons were performed using independent samples t-tests and chi-square analyses.
Two hundred seven patients were identified—75 who underwent PSF and 132 treated with 3CO. In the latter group, patients were older (58.9 vs 49.4 years, p < 0.001), had a higher body mass index (29.0 vs 25.8, p = 0.029), smaller preoperative coronal Cobb measurements (33.8° vs 56.4°, p < 0.001), more preoperative sagittal malalignment (11.7 cm vs 5.4 cm, p < 0.001), and similar sagittal Cobb measurements (45.8° vs 57.7°, p = 0.113). Operating times were similar (393 vs 423 minutes, p = 0.130), although patients in the 3CO group sustained higher estimated blood loss (2120 vs 1700 ml, p = 0.066). Rates of new neurological deficits were similar (PSF: 6.7% vs 3CO: 9.9%, p = 0.389), and rates of any perioperative medical complication were similar (PSF: 46.7% vs 3CO: 50.8%, p = 0.571). Patients who underwent vertebral column resection (VCR) were more likely to sustain medical complications than those treated with pedicle subtraction osteotomy (73.7% vs 46.9%, p = 0.031), although new neurological deficits were similar (15.8% vs 8.8%, p = 0.348). Regression analysis did not reveal significant predictors of neurological injury or complication from collected data.
Despite higher estimated blood loss, rates of all complications (49.3%) and new neurological deficits (8.7%) did not vary for patients who underwent complex reconstruction, whether or not a 3CO was performed. Patients who underwent VCR sustained more medical complications without an increase in new neurological deficits. Prospective studies of patient factors, provider factors, and refined surgical data are needed to define and optimize risk factors for complication and neurological deficits.
Pierce D. Nunley, Gregory M. Mundis Jr., Richard G. Fessler, Paul Park, Joseph M. Zavatsky, Juan S. Uribe, Robert K. Eastlack, Dean Chou, Michael Y. Wang, Neel Anand, Kelly A. Frank, Marcus B. Stone, Adam S. Kanter, Christopher I. Shaffrey, Praveen V. Mummaneni and the International Spine Study Group
The aim of this study was to educate medical professionals about potential financial impacts of improper diagnosis-related group (DRG) coding in adult spinal deformity (ASD) surgery.
Medicare’s Inpatient Prospective Payment System PC Pricer database was used to collect 2015 reimbursement data for ASD procedures from 12 hospitals. Case type, hospital type/location, number of operative levels, proper coding, length of stay, and complications/comorbidities (CCs) were analyzed for effects on reimbursement. DRGs were used to categorize cases into 3 types: 1) anterior or posterior only fusion, 2) anterior fusion with posterior percutaneous fixation with no dorsal fusion, and 3) combined anterior and posterior fixation and fusion.
Pooling institutions, cases were reimbursed the same for single-level and multilevel ASD surgery. Longer stay, from 3 to 8 days, resulted in an additional $1400 per stay. Posterior fusion was an additional $6588, while CCs increased reimbursement by approximately $13,000. Academic institutions received higher reimbursement than private institutions, i.e., approximately $14,000 (Case Types 1 and 2) and approximately $16,000 (Case Type 3). Urban institutions received higher reimbursement than suburban institutions, i.e., approximately $3000 (Case Types 1 and 2) and approximately $3500 (Case Type 3). Longer stay, from 3 to 8 days, increased reimbursement between $208 and $494 for private institutions and between $1397 and $1879 for academic institutions per stay.
Reimbursement is based on many factors not controlled by surgeons or hospitals, but proper DRG coding can significantly impact the financial health of hospitals and availability of quality patient care.
Michael Y. Wang, Praveen V. Mummaneni, Kai-Ming G. Fu, Neel Anand, David O. Okonkwo, Adam S. Kanter, Frank La Marca, Richard Fessler, Juan Uribe, Christopher I. Shaffrey, Virginie Lafage, Raqeeb M. Haque, Vedat Deviren and Gregory M. Mundis Jr.
Minimally invasive surgery (MIS) options for the treatment of adult spinal deformity (ASD) have advanced significantly over the past decade. However, a wide array of options have been described as being MIS or less invasive. In this study the authors investigated a multiinstitutional cohort of patients with ASD who were treated with less invasive methods to determine the extent of deformity correction achieved.
This study was a retrospective review of multicenter prospectively collected data in 85 consecutive patients with ASD undergoing MIS surgery. Inclusion criteria were as follows: age older than 45 years; minimum 20° coronal lumbar Cobb angle; and 1 year of follow-up. Procedures were classified as follows: 1) stand-alone (n = 7); 2) circumferential MIS (n = 43); or 3) hybrid (n = 35).
An average of 4.2 discs (range 3–7) were fused, with a mean follow-up duration of 26.1 months in this study. For the stand-alone group the preoperative Cobb range was 22°–51°, with 57% greater than 30° and 28.6% greater than 50°. The mean Cobb angle improved from 35.7° to 30°. A ceiling effect of 23° for curve correction was observed, regardless of preoperative curve severity. For the circumferential MIS group the preoperative Cobb range was 19°–62°, with 44% greater than 30° and 5% greater than 50°. The mean Cobb angle improved from 32° to 12°. A ceiling effect of 34° for curve correction was observed. For the hybrid group the preoperative Cobb range was 23°–82°, with 74% greater than 30° and 23% greater than 50°. The mean Cobb angle improved from 43° to 15°. A ceiling effect of 55° for curve correction was observed.
Specific procedures for treating ASD have particular limitations for scoliotic curve correction. Less invasive techniques were associated with a reduced ability to straighten the spine, particularly with advanced curves. These data can guide preoperative technique selection when treating patients with ASD.
Praveen V. Mummaneni, Christopher I. Shaffrey, Lawrence G. Lenke, Paul Park, Michael Y. Wang, Frank La Marca, Justin S. Smith, Gregory M. Mundis Jr., David O. Okonkwo, Bertrand Moal, Richard G. Fessler, Neel Anand, Juan S. Uribe, Adam S. Kanter, Behrooz Akbarnia and Kai-Ming G. Fu
Minimally invasive surgery (MIS) is an alternative to open deformity surgery for the treatment of patients with adult spinal deformity. However, at this time MIS techniques are not as versatile as open deformity techniques, and MIS techniques have been reported to result in suboptimal sagittal plane correction or pseudarthrosis when used for severe deformities. The minimally invasive spinal deformity surgery (MISDEF) algorithm was created to provide a framework for rational decision making for surgeons who are considering MIS versus open spine surgery.
A team of experienced spinal deformity surgeons developed the MISDEF algorithm that incorporates a patient's preoperative radiographic parameters and leads to one of 3 general plans ranging from MIS direct or indirect decompression to open deformity surgery with osteotomies. The authors surveyed fellowship-trained spine surgeons experienced with spinal deformity surgery to validate the algorithm using a set of 20 cases to establish interobserver reliability. They then resurveyed the same surgeons 2 months later with the same cases presented in a different sequence to establish intraobserver reliability. Responses were collected and tabulated. Fleiss' analysis was performed using MATLAB software.
Over a 3-month period, 11 surgeons completed the surveys. Responses for MISDEF algorithm case review demonstrated an interobserver kappa of 0.58 for the first round of surveys and an interobserver kappa of 0.69 for the second round of surveys, consistent with substantial agreement. In at least 10 cases there was perfect agreement between the reviewing surgeons. The mean intraobserver kappa for the 2 surveys was 0.86 ± 0.15 (± SD) and ranged from 0.62 to 1.
The use of the MISDEF algorithm provides consistent and straightforward guidance for surgeons who are considering either an MIS or an open approach for the treatment of patients with adult spinal deformity. The MISDEF algorithm was found to have substantial inter- and intraobserver agreement. Although further studies are needed, the application of this algorithm could provide a platform for surgeons to achieve the desired goals of surgery.
Anthony L. Asher, Panagiotis Kerezoudis, Praveen V. Mummaneni, Erica F. Bisson, Steven D. Glassman, Kevin T. Foley, Jonathan R. Slotkin, Eric A. Potts, Mark E. Shaffrey, Christopher I. Shaffrey, Domagoj Coric, John J. Knightly, Paul Park, Kai-Ming Fu, Clinton J. Devin, Kristin R. Archer, Silky Chotai, Andrew K. Chan, Michael S. Virk and Mohamad Bydon
Patient-reported outcomes (PROs) play a pivotal role in defining the value of surgical interventions for spinal disease. The concept of minimum clinically important difference (MCID) is considered the new standard for determining the effectiveness of a given treatment and describing patient satisfaction in response to that treatment. The purpose of this study was to determine the MCID associated with surgical treatment for degenerative lumbar spondylolisthesis.
The authors queried the Quality Outcomes Database registry from July 2014 through December 2015 for patients who underwent posterior lumbar surgery for grade I degenerative spondylolisthesis. Recorded PROs included scores on the Oswestry Disability Index (ODI), EQ-5D, and numeric rating scale (NRS) for leg pain (NRS-LP) and back pain (NRS-BP). Anchor-based (using the North American Spine Society satisfaction scale) and distribution-based (half a standard deviation, small Cohen’s effect size, standard error of measurement, and minimum detectable change [MDC]) methods were used to calculate the MCID for each PRO.
A total of 441 patients (80 who underwent laminectomies alone and 361 who underwent fusion procedures) from 11 participating sites were included in the analysis. The changes in functional outcome scores between baseline and the 1-year postoperative evaluation were as follows: 23.5 ± 17.4 points for ODI, 0.24 ± 0.23 for EQ-5D, 4.1 ± 3.5 for NRS-LP, and 3.7 ± 3.2 for NRS-BP. The different calculation methods generated a range of MCID values for each PRO: 3.3–26.5 points for ODI, 0.04–0.3 points for EQ-5D, 0.6–4.5 points for NRS-LP, and 0.5–4.2 points for NRS-BP. The MDC approach appeared to be the most appropriate for calculating MCID because it provided a threshold greater than the measurement error and was closest to the average change difference between the satisfied and not-satisfied patients. On subgroup analysis, the MCID thresholds for laminectomy-alone patients were comparable to those for the patients who underwent arthrodesis as well as for the entire cohort.
The MCID for PROs was highly variable depending on the calculation technique. The MDC seems to be a statistically and clinically sound method for defining the appropriate MCID value for patients with grade I degenerative lumbar spondylolisthesis. Based on this method, the MCID values are 14.3 points for ODI, 0.2 points for EQ-5D, 1.7 points for NRS-LP, and 1.6 points for NRS-BP.
David B. Bumpass, Lawrence G. Lenke, Jeffrey L. Gum, Christopher I. Shaffrey, Justin S. Smith, Christopher P. Ames, Shay Bess, Brian J. Neuman, Eric Klineberg, Gregory M. Mundis Jr., Frank Schwab, Virginie Lafage, Han Jo Kim, Douglas C. Burton, Khaled M. Kebaish, Richard Hostin, Renaud Lafage, Michael P. Kelly and for the International Spine Study Group
Adolescent spine deformity studies have shown that male patients require longer surgery and have greater estimated blood loss (EBL) and complications compared with female patients. No studies exist to support this relationship in adult spinal deformity (ASD). The purpose of this study was to investigate associations between sex and complications, deformity correction, and health-related quality of life (HRQOL) in patients with ASD. It was hypothesized that male ASD patients would have greater EBL, longer surgery, and more complications than female ASD patients.
A multicenter ASD cohort was retrospectively queried for patients who underwent primary posterior-only instrumented fusions with a minimum of 5 levels fused. The minimum follow-up was 2 years. Primary outcomes were EBL, operative time, intra-, peri-, and postoperative complications, radiographic correction, and HRQOL outcomes (Oswestry Disability Index, SF-36, and Scoliosis Research Society-22r Questionnaire). Poisson multivariate regression was used to control for age, comorbidities, and levels fused.
Ninety male and 319 female patients met the inclusion criteria. Male patients had significantly greater mean EBL (2373 ml vs 1829 ml, p = 0.01). The mean operative time, transfusion requirements, and final radiographic measurements did not differ between sexes. Similarly, changes in HRQOL showed no significant differences. Finally, there were no sex differences in the incidence of complications (total, major, or minor) at any time point after controlling for age, body mass index, comorbidities, and levels fused.
Despite higher EBL, male ASD patients did not experience more complications or require less deformity correction at the 2-year follow-up. HRQOL scores similarly showed no sex differences. These findings differ from adolescent deformity studies, and surgeons can counsel patients that sex is unlikely to influence the outcomes and complication rates of primary all-posterior ASD surgery.