Allan R. Martin, Sukhvinder Kalsi-Ryan, Muhammad A. Akbar, Anna C. Rienmueller, Jetan H. Badhiwala, Jefferson R. Wilson, Lindsay A. Tetreault, Aria Nouri, Eric M. Massicotte, and Michael G. Fehlings
This study sought to investigate functional outcomes of patients with degenerative cervical myelopathy who were managed nonoperatively and the utility of quantitative clinical measures and anatomical MRI to detect deterioration. The results suggest that degenerative cervical myelopathy has a poor natural history, with more than 50% deteriorating in short- to midterm follow-up. Clinical assessments to detect deterioration should include the modified Japanese Orthopaedic Association score, grip strength, dexterity, balance, and gait analysis. Anatomical MRI and modified Japanese Orthopaedic Association score (as a stand-alone clinical measure) are insufficient to identify neurological deterioration in the majority of cases.
Peter G. Passias, Haddy Alas, Sara Naessig, Han Jo Kim, Renaud Lafage, Christopher Ames, Eric Klineberg, Katherine Pierce, Waleed Ahmad, Douglas Burton, Bassel Diebo, Shay Bess, D. Kojo Hamilton, Munish Gupta, Paul Park, Breton Line, Christopher I. Shaffrey, Justin S. Smith, Frank Schwab, Virginie Lafage, and the International Spine Study Group
This study analyzed cervical deformity conversion following corrective surgery for adult spinal deformity across radiographic parameters, proximal junctional kyphosis rates, revision rates, and clinical factors. Conversion from baseline cervical alignment to postoperative cervical deformity occurred the most within the immediate postoperative period (<6 weeks), although late conversion up to 3 years was also observed. Predictors of cervical deformity conversion included higher baseline pelvic incidence–lumbar lordosis mismatch and lower thoracic kyphosis and lumbar lordosis. Higher cervical lordosis, C2–T3 angle, body mass index, and Charlson Comorbidity Index were specific positive predictors of late (1- to 3-year) cervical deformity conversion.
The authors investigated the effects of cervical reconstruction on global sagittal alignment, including lower extremities and HRQOL. Patients with cervical kyphosis showed compensatory changes in the upper cervical spine and thoracolumbar spine instead of in the lower extremities, which resolved reciprocally in a different manner in the head- and trunk-balanced subtypes. Reciprocal change occurs differently according to the subtype of cervical kyphosis.
S. Harrison Farber, David J. Mauler, Soumya Sagar, Mark A. Pacult, Corey T. Walker, Michael A. Bohl, Laura A. Snyder, Kristina M. Chapple, Volker K. H. Sonntag, Juan S. Uribe, Jay D. Turner, Steve W. Chang, and U. Kumar Kakarla
The authors reviewed a large institutional series of patients undergoing 4- and 5-level anterior cervical discectomy and fusion procedures. They found that 57% of patients experienced transient dysphagia, with rates decreasing to 6% and 2.8% at 1 and 2 years, respectively. Short-term dysphagia was more likely in patients with a larger increase in lordosis postoperatively. This study provides information to help counsel patients regarding their risk of swallowing difficulty after this procedure.
Yang Li, Benlong Shi, Dun Liu, Zhen Liu, Xu Sun, Yong Qiu, and Zezhang Zhu
This study described a novel sequential correction technique and compared the results with the traditional correction technique. The results revealed that this technique could significantly and practically reduce the difficulty of rod installation with a better correction rate of the deformity and fewer complications. The technique could serve as a safe and effective method for better postoperative radiographic and clinical outcomes for the surgical treatment of severe thoracic idiopathic scoliosis.
Sebastian Salas-Vega, Vikram B. Chakravarthy, Robert D. Winkelman, Matthew M. Grabowski, Ghaith Habboub, Jason W. Savage, Michael P. Steinmetz, and Thomas E. Mroz
The authors sought to identify the drivers of length of stay (LOS) in the hospital following elective lumbar laminectomy and to understand their relationships with patient outcomes and costs. Even after adjusting for underlying health risks, the authors found that discharge to specialty care facilities and late-week surgery are significant predictors of prolonged LOS and result in greater costs of care. Efforts to optimize surgical scheduling and care coordination may help lower costs and improve patient experience without changing neurosurgical care.
Nicholas M. Rabah, Hammad A. Khan, Robert D. Winkelman, Jay M. Levin, Thomas E. Mroz, and Michael P. Steinmetz
The authors used the Consumer Assessment of Healthcare Providers and Systems Clinician & Group Survey to assess the key drivers of patient satisfaction with their surgeon after lumbar spine surgery. Top-box responses on those questions pertaining to physician communication were found to be associated with the greatest likelihood of overall satisfaction. This confirms the importance of effective communication in the patient-provider interaction and points to potential prospects for quality improvement efforts in the spine care setting.
Corey T. Walker, Jakub Godzik, Santiago Angel, Juan Pedro Giraldo, Jay D. Turner, and Juan S. Uribe
This study evaluates the treatment of coronal deformity in patients treated with circumferential minimally invasive surgical fusion in which lateral and anterior lumbar interbody fusion with percutaneous pedicle screw fixation were used. This study is the first to examine coronal malalignment in this context. Circumferential minimally invasive surgical fusion is successful at correcting coronal malalignment in most patients; however, patients whose preoperative truncal shift is toward the convexity of their major curve (type C) remain the most difficult to treat.
Robert E. Harbaugh, Clinton Devin, Michelle B. Leavy, Zoher Ghogawala, Kristin R. Archer, Mohamad Bydon, Christine Goertz, Doron Dinstein, David R. Nerenz, Guy S. Eakin, William Lavelle, William O. Shaffer, Paul M. Arnold, Charles H. Washabaugh, and Richard E. Gliklich
The authors engaged in an ongoing effort to reach consensus on a core set of outcome measures and harmonize the measure definitions across patient registries that collect large amounts of data on degenerative lumbar spondylolisthesis treatment pathways and patient outcomes. This process will make it easier to connect data across registries to answer research questions, support clinical decision-making, and ultimately improve patient outcomes.
Within a randomized clinical trial, standard titanium alloy and stiffer cobalt-chromium rods were compared on their ability to support adolescent idiopathic scoliosis (AIS) surgical deformity correction. This study found that both titanium alloy and cobalt-chromium supported clinically significant spine deformity corrections and pain, self-image, and disability scores at similar rates. This work reveals that both materials are equally effective in correcting AIS, suggesting that rod selection should primarily involve considerations regarding material costs, MRI compatibility, and rod profile longevity.
Peter G. Passias, Haddy Alas, Shay Bess, Breton G. Line, Virginie Lafage, Renaud Lafage, Christopher P. Ames, Douglas C. Burton, Avery Brown, Cole Bortz, Katherine Pierce, Waleed Ahmad, Sara Naessig, Michael P. Kelly, Richard Hostin, Khaled M. Kebaish, Khoi D. Than, Pierce Nunley, Christopher I. Shaffrey, Eric O. Klineberg, Justin S. Smith, Frank J. Schwab, and the International Spine Study Group
Researchers aimed to identify patient-related factors and radiographic parameters associated with an increased risk for inferior health-related quality-of-life scores in nonoperative (N-Op) patients with adult spinal deformity. When controlling for baseline deformity in N-Op versus operative (Op) patients, subsequent deterioration in frailty, BMI, and radiographic progression over the 2-year follow-up were found to drive suboptimal patient-reported outcome measures in N-Op cohorts as measured by validated Oswestry Disability Index and Scoliosis Research Society clinical instruments. These findings may be incorporated into clinical decision-making to aid surgeons in providing treatment options that achieve the best possible patient outcomes.
Tianyuan Zhang, Hongda Bao, Shibin Shu, Zhen Liu, Xu Sun, Bin Wang, Yong Qiu, and Zezhang Zhu
In this study, the authors aimed to evaluate the clinical outcomes of different distal fixation anchors in lumbosacral spinal deformities associated with sacral agenesis. They found that S2AI screws can achieve a more satisfactory correction with fewer implant-related complications than occurred with S1 and iliac screws. These findings provide surgeons with a better understanding of spinopelvic fixation and may guide surgical decision-making for patients with lumbosacral scoliosis associated with sacral agenesis.
Katsuhiro Mizutani, Arturo Consoli, Federico Di Maria, Stéphanie Condette Auliac, Anne Boulin, Oguzhan Coskun, Julie Gratieux, and Georges Rodesch
This study aims to classify intradural spinal arteriovenous shunts (ID-SAVSs) into 5 types of lesions, based on the precise anatomical disposition, angioarchitectonics, and spinal histogenetic segmentations. Each type of lesion is associated with specific genetic nonhereditary and hereditary syndromes, specific angioarchitectonics, and a specific distribution in spinal histogenetic segmentation. The current classification will facilitate a better understanding of the pathophysiology and etiology of ID-SAVSs and better therapeutic management.
Takahisa Hishiya, Tetsuhiro Ishikawa, and Mitsutoshi Ota
Researchers retrospectively evaluated the effectiveness of posterior spinal fixation with penetrating endplate screws (PESs) in patients with diffuse idiopathic skeletal hyperostosis (DISH)-related thoracolumbar fractures. Patients treated with the PES technique had less blood loss, shorter range of fixation, and less screw loosening than those with the conventional pedicle screw technique. This simple and highly fixable PES technique may be an ideal spinal fixation procedure for DISH-related fractures.
Arnold H. Menezes, Scott C. Seaman, Matthew A. Howard III, Patrick W. Hitchon, and Elizabeth B. Takacs
The authors sought to provide information on primary adult tethered cord syndrome (TCS). The pathologies found in 24 patients analyzed were diastematomyelia, TCS with conus lipoma, and TCS with taut filum terminale. Despite previous neurosurgical or orthopedic evaluations, no patients had missed cases of neurocutaneous stigmata or scoliosis. The triad of nondermatomal back or perineal pain, bladder dysfunction, and preexisting neurological deficits raises suspicion of a TCS diagnosis. In patients with symptom duration less than 3 years, objective postoperative improvement was documented.
The authors analyzed the adjacent-level mobility of single-level L3–4 cortical screw–rod (CSR) versus pedicle screw–rod (PSR) fixation with and without interbody support. The use of PSR versus CSR significantly affects mobility at the adjacent level, regardless of the type of interbody support. Biomechanical evaluations of adjacent-level mobility with different screw trajectories have not been previously reported. These findings provide useful insights for clinical decision-making based on cortical bone trajectories and outcomes, as well as for future investigations.
This study analyzed the biomechanical effects of adding a titanium triangular-shaped sacroiliac implant to a long-segment lumbopelvic construct with S2-alar-iliac screws. The analysis showed that the posteriorly placed device improved local stability of the sacroiliac joint without significantly affecting rod and screw strains at the lumbosacral junction. These findings were intended to help clinicians understand the in vitro biomechanical effects of supplementing adult deformity correction constructs with a sacroiliac fusion device.
This study aimed to evaluate the comparative accuracy and safety of navigation-based approaches for cervical pedicle screw placement versus fluoroscopic techniques. It was found that navigation-based techniques confer a statistically significantly more accurate screw placement and resultant lower complication rates. This review adds to the current knowledge of cervical pedicle screws by directly comparing fluoroscopic and navigation-based pedicle screw insertion techniques for their accuracy and safety in a systematic manner.
The incidence of adjacent-segment disease (ASD) necessitating reoperation has been well described following traditional posterior lumbar fusion techniques (2.5%–3.9% per year); however, the incidence of surgical ASD remains poorly characterized following the less invasive stand-alone lateral lumbar interbody fusion (LLIF). The objective of this study was to identify the incidence of ASD following LLIF for degenerative lumbar etiologies, which was noted to be 0.88% per year in this study cohort. Given this relatively lower rate of ASD, LLIF may be preferable for properly selected and appropriately indicated patients.
To investigate whether blood flow of a compressed spinal cord improves after decompressive surgery for cervical spondylotic myelopathy, regional blood flow was measured precisely in a cervical chronic compression model in rats by using a fluorescent microsphere technique. Chronic mechanical compression induced segmental spinal cord blood flow insufficiency and development of myelopathy. Subsequent decompressive surgery brought about sequential blood flow recovery. These results suggest that blood flow alterations may play a significant role in neurological changes.
Long-term changes in sagittal spinopelvic alignment in patients with lumbar spinal stenosis (LSS) after decompression surgery remain unclear. This study revealed that a significant percentage of patients with LSS could obtain normal sagittal balance in the short term and mid- to long term after decompression surgery alone. Preoperative sagittal vertical axis (SVA) and postoperative SVA, pelvic incidence minus lumbar lordosis, and pelvic tilt affected clinical outcomes after decompression alone. The clinical outcomes of patients with persistent postural malalignment tended to deteriorate more than those of other patients.
In this study, the authors analyzed factors associated with an academic career trajectory among fellowship-trained spinal neurosurgeons. Increased protected research time during residency, higher h-index during residency, completing more than one clinical fellowship, and attending any of the top 5 programs that graduated the most fellows in the study cohort were all independently associated with an academic career. The study findings may be useful in developing programs to encourage residents who are interested in academic spinal neurosurgery.
The objective of this study was to assess the cerebral functional and macrostructural changes that occur after surgical decompression in patients with degenerative cervical myelopathy. The key finding was that increased functional connectivity between the cerebellum and primary sensorimotor areas was found to be positively associated with the neurological improvement in patients with degenerative cervical myelopathy (DCM). This study helps us to better understand the importance of supraspinal plasticity in the pathogenesis of DCM and its role in neurological recovery.
Although statistical significance is pertinent to research, p values are extremely sensitive to sample size and often fall short in demonstrating clinical efficacy. Minimal clinical important difference (MCID) values are used to determine the minimum change necessary to achieve meaningful improvement. This was the first study to successfully establish MCID thresholds for several prominent pain assessments after spinal cord stimulation (SCS), resulting in ability to better determine patients' success with and response to SCS therapy.
The objective of this study was to compare preoperative and postoperative gait posture and ability in elderly patients with adult spinal deformity (ASD) who underwent extensive corrective fusion from the thoracic spine to pelvis according to age. Elderly patients with ASD had improved gait after surgery to the same extent as middle-aged patients. The study results are useful for both elderly patients with ASD and surgeons considering surgical indications for their patients.
The objective of this study was to evaluate the correlation between increasing frailty, outcomes, and complications among patients undergoing single-level transforaminal lumbar interbody fusion. Not surprisingly, it was demonstrated that as modified frailty index scores increased patients experienced longer inpatient hospital stays, a higher probability of discharge to a nursing or rehabilitation facility, and increased complications. These data may help inform physicians in their patient selection for lumbar fusion.
The objective of this study was to evaluate the safety and efficacy of a novel lumbar interbody fusion device. The results demonstrated endplate surface area coverage similar to an anterior lumbar interbody fusion, but via a minimally invasive transforaminal lumbar interbody fusion approach. The device was not only safe but demonstrated itself to be very effective, with a high fusion rate and low failure rate.
The aim of this study was to compare a traditional cervical cage with a zero-profile fixation device in patients who underwent three-level anterior cervical decompression and fusion in terms of clinical and radiological outcomes and complications. Use of zero-profile implants yielded satisfactory long-term outcomes that were similar to those of a standard anterior cage-plate construct. This study could provide a reference for surgeons to choose the appropriate surgical option for patients with multilevel cervical spondylotic myelopathy.
A novel, minimally invasive, anteroposterior combined surgery with lateral lumbar interbody fusion was used to overcome the drawbacks of conventional procedures to treat lumbar spinal canal stenosis associated with osteoporotic vertebral collapse. With tailored placement of interbody cages and pedicle screws according to the morphology of the collapsed vertebra, this procedure avoids corpectomy and achieves neural decompression, correction of local alignment, and reconstruction of anterior support with a rigid, minimally invasive, short-segment fusion construct.
This study compares template-guided (TG) and standard freehand (FH) pedicle screw insertion techniques in a randomized controlled trial (RCT). High accuracy with less intraoperative radiation exposure could be achieved using the TG technique. The pros and cons of the TG technique have been illuminated in one of the first RCTs.
Researchers investigated the reciprocal changes in the cervical spine after lumbar pedicle subtraction osteotomy in ankylosing spondylitis-related thoracolumbar kyphosis. Different patterns of cervical reciprocal changes occurred based on the presence or absence of ossification of the anterior longitudinal ligament in the lower cervical spine. The clinical significance of the relationship between cervical reciprocal changes and osteotomy angle suggested that reciprocal cervical changes should be considered when approximating the osteotomy angle for ankylosing spondylitis patients with thoracolumbar kyphosis preoperatively.
The objective of this study was to determine whether patient expectations of spine surgery were different depending on their preoperative diagnosis. The authors found that patient-reported symptoms, and not the diagnosis, had a significant impact. Cervical myelopathy patients had lower expectations than patients with other pathoanatomical diagnoses. The results of this study illustrate the importance of focusing preoperative discussions on preoperative symptoms, rather than diagnosis, when speaking about expectations from spine surgery.
Machine learning was used to examine the value of clinical and demographic variables in conjunction with expectations and quality-of-life appraisal in predicting outcomes following spine surgery. Different expectations and appraisal processes played a role in long- versus short-term predictions, suggesting that cognitive adaptation is important and relevant to pain relief outcomes after spine surgery. These results underscore the importance of addressing how patients think about quality of life and surgery outcomes to maximize the benefits of surgery.
This is the largest retrospective analysis of access to the concave side of the coronal curve in adult degenerative scoliosis and associated morbidity. This study illustrates the safety of concave access in a large, retrospective, multi-institutional cohort.
Researchers created a novel method of using clinical photographs to assess spinal alignment in patients with deformity. Photographic measurements of deformity are found to be highly correlated with radiographic equivalents and can be used instead of radiographs or when full-spine images are unavailable.
The objective of this study was to characterize any racial disparities in elective spinal surgery utilizing the Michigan Spine Surgery Improvement Collaborative. The authors’ key finding was that patients who self-identified as African American had greater risk of dissatisfaction with elective spine surgery after adjusting for confounding factors on multivariate analysis. This study illustrates the potential interactions between race and outcome.
In this study, the authors sought to evaluate factors associated with a nonroutine discharge after surgery for cervical myelopathy by using a national registry. They found that socioeconomic and demographic characteristics including age, race, gender, insurance status, and employment status may be the most significant drivers of a nonroutine discharge. These findings may help care teams identify patients who are likely to require discharge to a rehabilitation facility or another postacute care institution and hence facilitate administrative aspects of patient discharge.
Preoperative radiographs were compared to determine thoracic flexibility, which is defined as the change in thoracic alignment between supine and standing radiographs. Thoracic flexibility was associated with proximal junctional kyphosis at 1 year. Patients with a large amount of thoracic flexibility may be at risk for thoracic flattening induced by intraoperative positioning, leading to an increased risk of proximal junctional kyphosis.
The authors investigated whether radiation exposure during percutaneous vertebroplasty (PV) or balloon kyphoplasty (BK) exceeds safety limits for patients and operators. Exposures were lower for PV than BK for both operators and patients, but both procedures were unlikely to exceed safety limits when standard radiation protection equipment was used. However, radiation to the hand may limit the number of procedures an operator can safely perform. Additional high-quality data are necessary to definitively establish exposure differences between procedures and evaluate impacts of newer techniques, such as CT-guided procedures.
In this study, the authors proposed a novel indicator, gROM (representing the gap between flexion and extension ranges of motion), for predicting the loss of cervical lordosis after laminoplasty in patients with cervical spondylotic myelopathy and examined its clinical performance. The study results demonstrated that gROM could be a highly useful indicator and that one exceeding 30° was a risk factor for a marked loss of cervical lordosis postoperatively.
Although short-term adult symptomatic lumbar scoliosis studies favor operative over nonoperative treatment, longer outcomes are critical because the majority of instrumentation failures occur 2–5 years after surgery. The objective of this study was to assess the durability of adult symptomatic lumbar scoliosis treatment. The findings demonstrate that the greater improvement of operative versus nonoperative treatment for adult symptomatic lumbar scoliosis at 2 years was durably maintained at the 5-year follow-up. These findings have important implications for patient counseling and cost-effectiveness assessments.
The authors performed quantitative assessments of indirect decompression on consecutively treated patients with transpsoas lateral interbody fusion using volumetric reconstructions of MRI. The authors found that tall preoperative disc height was predictive of clinical failure with indirect decompression alone, whereas decreased disc height, body mass index, and increased anterolisthesis correlated to radiographic increases in central canal dimensions. These results may provide surgeons with predictive preoperative variables to determine whether indirect decompression alone will be successful.
This study aimed to evaluate the overall rate, cause, and timing of reoperation procedures following anterior or lateral lumbar interbody fusions without direct posterior decompression. There was a low reoperation rate in this cohort. The majority of same-level reoperations were due to a need for further direct decompression, especially in patients with more severe preoperative stenosis. This study adds to the literature on reoperation rates and failure mechanisms following less invasive interbody procedures.
Using a national registry, the authors compared the relative efficacies of decompression alone and decompression plus fusion in patients with grade I lumbar spondylolisthesis, for which ideal surgical management has not been determined despite extensive investigation. After adjusting for differences between groups, fusion remained independently associated with Oswestry Disability Index (ODI) score improvement and achieving the minimal clinically important difference in ODI score at the 24-month follow-up. The results suggest that decompression plus fusion offers superior outcomes at 24 months posttreatment compared to decompression alone for grade I lumbar spondylolisthesis.
The authors tested the hypothesis that preoperative cerebrospinal fluid (CSF) biomarkers are altered in patients with cervical spondylotic myelopathy and correlate with neurological status and outcome. Biomarkers of glial and axonal damage in CSF biomarkers were increased, while amyloid breakdown products were decreased. Correlations between preoperative neurological picture and outcome were noted. CSF biomarkers can reflect the ongoing pathophysiology of spinal cord compression and damage and may provide prognostic information on surgical outcome.
The authors compared standing and supine radiographs for 73 patients and found that those with bilateral sacroiliac (SI) joint vacuum signs, as identified on CT, had a change in pelvic incidence between the supine and standing positions. This suggests there may be increasing motion across the SI joint with significant joint degeneration.
The objective of this study was to elucidate the efficacy of the cyst-dyeing method in microendoscopic spinal decompression surgery for lumbar spinal stenosis caused by facet cysts. The adjunctive cyst-dyeing method effectively delineated cyst and dural boundaries, facilitating safer and more effective cyst separation and neural decompression, even with microendoscopic surgery. Microendoscopic surgery combined with the authors' novel facet cyst-dyeing method is a safe and effective minimally invasive technique for facet-joint cysts.
The authors aimed to determine which radiological parameters related to the aging spine are associated with curve progression in early degenerative lumbar scoliosis (DLS), in particular which factors predict curve progression. In early DLS patients observed for a mean of 13.7 years, asymmetrical disc degeneration in the lower disc space of the apical vertebra, leading to lower apical vertebral disc wedging angles, was the most important factor in predicting curve progression. Therefore, patients with this finding need to be closely monitored.
Thoracic ossification of the posterior longitudinal ligament (OPLL) remains one of the most challenging disorders for spine surgeons. No ideal surgical procedures have been developed for patients with thoracic myelopathy caused by OPLL. In this study, the authors' technique of modified decompression through a posterior approach clearly resulted in better surgical results, with the recovery rate of the Japanese Orthopaedic Association score > 70%. Patients who are nonambulatory due to thoracic OPLL could become able to walk again after this procedure.
The objective of this study was to estimate the incidence rate of spine-specific skeletal related events (SREs) in patients with non–small cell lung cancer and to quantify the impact of SREs on overall mortality. The presence of SREs was found to be associated with an increased incidence rate of mortality. The observed findings may be used to help patients and providers make treatment decisions based on the presence (or lack thereof) of SREs.
The authors studied the epidemiology of spinal cord astrocytoma (SCA) between 1995 and 2016, utilizing the Central Brain Tumor Registry of the United States database to provide a comprehensive epidemiological description of SCAs. The most important finding/contribution of this work to the literature is the description of age-adjusted incidence trends between 1995 and 2016, along with SCA incidence stratified by histology and patient demographics. Due to the rarity of SCA, it has since evaded complete epidemiological description. This study represents the most comprehensive epidemiological descriptions of SCAs to date.
The authors' aim was to demonstrate short-term outcomes of minimally invasive endoscopic surgery in patients with degenerative lumbar disease with either ossification or calcification of the ligamentum flavum. The short-term improvement in Japanese Orthopaedic Association score was significantly lower in patients with degenerative lumbar disease with ossification than in the matched control group. In contrast, there were no significant differences in these scores and perioperative outcomes between patients with calcification and their matched control group. The surgical indications of minimally invasive posterior decompression for patients with calcification can be the same as for patients without calcification; however, indications for patients with ossification should be investigated in future studies, including other surgical methods.
In this article, the surgical technique and outcomes of using the free vascularized fibula graft for the reconstruction of spinal defects following total en bloc spondylectomy are described. This reconstruction technique was deemed to be effective, particularly in the cervicothoracic spine. There were high failure rates in the lumbar spine; thus, methods to increase the weight-bearing capacity of the graft should be considered in the lumbar spine.