Anterior approaches for cervical spondylotic myelopathy: which? When? How?

Cervical spondylotic myelopathy is a degenerative disorder with an unfavorable natural history. Surgical treatment options have evolved substantially over time, with both anterior and posterior methods proving successful for certain patients with specific characteristics. Anterior decompression of the spinal canal plus fusion techniques for stabilization has several advantages and some disadvantages when compared to posterior options. Understanding the pros and cons of the approaches and techniques is critical for the surgeon to select the best operative treatment strategy for any given patient to achieve the best outcome. Multiple decision-making factors are involved, such as sagittal alignment, number of levels, shape of the pathoanatomy, age and comorbidities, instability, and pre-operative pain levels. Any or all of these factors may be relevant for a given patient, and to varying degrees of importance. Choice of operative approach will therefore be dependent on patient presentation, risks of that approach for a given patient, and to some degree surgeon experience.

Delayed fracture of fibular strut allograft following three-level anterior cervical corpectomy and fusion: a case report.

Strut allografts are used in cervical spine reconstruction following corpectomy. A stress fracture in the graft is a rare event. We explain a late stress fracture of an allograft following anterior cervical fusion. A 57-year-old male with a history of cervical myeloradiculopathy underwent a three-level anterior cervical corpectomy and allograft reconstruction from C3-C7. Fracture lucencies in the allograft were identified on flexion/extension radiographs 11 months post-operatively. The patient reported no new pain, numbness, or weakness and denied any traumatic injury. Three years post-operatively, he was asymptomatic with no change in alignment or signs of failure of the instrumentation or strut graft. With a healed fibular strut allograft, a delayed stress fracture may be observed with a favorable outcome.

Late Retropharyngeal and Parapharyngeal Abscess in Patients with a History of Anterior Cervical Discectomy and Fusion.

OBJECTIVE: Anterior cervical discectomy and fusion is a common procedure performed by spine surgeons with rare complications and high treatment success. Late presentation of retropharyngeal abscess in patients with a history of anterior cervical discectomy and fusion is rare but can have devastating consequences. There is a paucity of data to guide medical and surgical management of retropharyngeal abscess in these patients. METHODS: We discuss 7 patients who presented to our institution with a late retropharyngeal abscess after having a history of anterior cervical discectomy and fusion. A review and description of the current literature regarding treatment and outcomes is described. RESULTS: Seven patients presented to our institution with a retropharyngeal abscess ranging from 10 months to 7 years after undergoing anterior cervical discectomy and fusion. All patients received at least a 6-week course of appropriate intravenous antibiotics. Only one patient had their initial ACDF instrumentation removed at the time of presentation for the abscess. Four out of the 7 patients were treated with irrigation and debridement in addition to intravenous antibiotics, whereas 3 patients were treated with no surgery and intravenous antibiotics alone. All patients were asymptomatic at final follow up. CONCLUSIONS: Late retropharyngeal abscess after anterior cervical discectomy and fusion is a rare complication. Surgical management should be considered along with long term antibiotics. Removal of implants may not be necessary for infection resolution. Antibiotic treatment alone may be indicated for patients who are not septic, do not have airway compromise, or and can be considered for poor surgical candidates.

Complications of Spine Surgery in "Super Obese" Patients.

STUDY DESIGN: Retrospective chart review with matched control. OBJECTIVE: To evaluate the indications and complications of spine surgery on super obese patients. METHODS: A retrospective review assessed super obese patients undergoing spine surgery at a level-1 trauma and spine referral center from 2012 to 2016. Outcomes were compared to age-matched controls with body mass index (BMI) <50 kg/m2. The control group was further subdivided into patients with BMI <30 kg/m2 (normal) and BMI between 30 and 50 kg/m2 (obese). RESULTS: Sixty-three super obese patients undergoing 86 surgeries were identified. Sixty patients (78 surgeries) were in the control group. Age and number of elective versus nonelective cases were not significantly different. Mean BMI of the super obese group was 55 kg/m2 (range 50-77 kg/m2) versus 29 kg/m2 in the controls (range 20-49 kg/m2). Fifty-two percent of surgeries were elective, and the most common indication was degenerative disease (39%). Compared with controls, super obese patients had a higher complication rate (30% [n = 19] vs 10% [N = 6], P = .0055) but similar 30-day mortality rate (5% vs 5%), a finding that was upheld when comparing super obese with each of the control group stratifications (BMI 30-50 and BMI <30 kg/m2). The most common complication among super obese patients was wound dehiscence/infection (n = 8, 13%); 2 patients' surgeries were aborted. Complication rates for elective surgery were 21% (n = 7) for super obese patients and 4% (n = 1) for controls (P = .121); complication rates for nonelective procedures were 40% (n = 12) and 14% (n = 5), respectively (P = .023). CONCLUSION: The complication rate of spine surgery in super obese patients (BMI ≥ 50 kg/m2) is significantly higher than other patients, particularly for nonelective cases.

Cervical fusion for treatment of degenerative conditions: development of appropriate use criteria.

BACKGROUND CONTEXT: High quality evidence is difficult to generate, leaving substantial knowledge gaps in the treatment of spinal conditions. Appropriate use criteria (AUC) are a means of determining appropriate recommendations when high quality evidence is lacking. PURPOSE: Define appropriate use criteria (AUC) of cervical fusion for treatment of degenerative conditions of the cervical spine. STUDY DESIGN/SETTING: Appropriate use criteria for cervical fusion were developed using the RAND/UCLA appropriateness methodology. Following development of clinical guidelines and scenario writing, a one-day workshop was held with a multidisciplinary group of 14 raters, all considered thought leaders in their respective fields, to determine final ratings for cervical fusion appropriateness for various clinical situations. OUTCOME MEASURES: Final rating for cervical fusion recommendation as either "Appropriate," "Uncertain" or "Rarely Appropriate" based on the median final rating among the raters. METHODS: Inclusion criteria for scenarios included patients aged 18 to 80 with degenerative conditions of the cervical spine. Key modifiers were defined and combined to develop a matrix of clinical scenarios. The median score among the raters was used to determine the final rating for each scenario. The final rating was compared between modifier levels. Spearman's rank correlation between each modifier and the final rating was determined. A multivariable ordinal regression model was fit to determine the adjusted odds of an "Appropriate" final rating while adjusting for radiographic diagnosis, number of levels and symptom type. Three decision trees were developed using decision tree classification models and variable importance for each tree was computed. RESULTS: Of the 263 scenarios, 47 (17.9 %) were rated as rarely appropriate, 66 (25%) as uncertain and 150 (57%) were rated as appropriate. Symptom type was the modifier most strongly correlated with the final rating (adjusted ρ2 = 0.58, p<.01). A multivariable ordinal regression adjusting for symptom type, diagnosis, and number of levels and showed high discriminative ability (C statistic = 0.90) and the adjusted odds ratio (aOR) of receiving a final rating of "Appropriate" was highest for myelopathy (aOR, 7.1) and radiculopathy (aOR, 4.8). Three decision tree models showed that symptom type and radiographic diagnosis had the highest variable importance. CONCLUSIONS: Appropriate use criteria for cervical fusion in the setting of cervical degenerative disorders were developed. Symptom type was most strongly correlated with final rating. Myelopathy or radiculopathy were most strongly associated with an "Appropriate" rating, while axial pain without stenosis was most associated with "Rarely Appropriate."

Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis.

BACKGROUND: Management of degenerative spondylolisthesis with spinal stenosis is controversial. Surgery is widely used, but its effectiveness in comparison with that of nonsurgical treatment has not been demonstrated in controlled trials. METHODS: Surgical candidates from 13 centers in 11 U.S. states who had at least 12 weeks of symptoms and image-confirmed degenerative spondylolisthesis were offered enrollment in a randomized cohort or an observational cohort. Treatment was standard decompressive laminectomy (with or without fusion) or usual nonsurgical care. The primary outcome measures were the Medical Outcomes Study 36-Item Short-Form General Health Survey (SF-36) bodily pain and physical function scores (100-point scales, with higher scores indicating less severe symptoms) and the modified Oswestry Disability Index (100-point scale, with lower scores indicating less severe symptoms) at 6 weeks, 3 months, 6 months, 1 year, and 2 years. RESULTS: We enrolled 304 patients in the randomized cohort and 303 in the observational cohort. The baseline characteristics of the two cohorts were similar. The one-year crossover rates were high in the randomized cohort (approximately 40% in each direction) but moderate in the observational cohort (17% crossover to surgery and 3% crossover to nonsurgical care). The intention-to-treat analysis for the randomized cohort showed no statistically significant effects for the primary outcomes. The as-treated analysis for both cohorts combined showed a significant advantage for surgery at 3 months that increased at 1 year and diminished only slightly at 2 years. The treatment effects at 2 years were 18.1 for bodily pain (95% confidence interval [CI], 14.5 to 21.7), 18.3 for physical function (95% CI, 14.6 to 21.9), and -16.7 for the Oswestry Disability Index (95% CI, -19.5 to -13.9). There was little evidence of harm from either treatment. CONCLUSIONS: In nonrandomized as-treated comparisons with careful control for potentially confounding baseline factors, patients with degenerative spondylolisthesis and spinal stenosis treated surgically showed substantially greater improvement in pain and function during a period of 2 years than patients treated nonsurgically. (ClinicalTrials.gov number, NCT00000409 [ClinicalTrials.gov].).

Complexities of spine surgery in obese patient populations: a narrative review.

The obese population is particularly challenging to the spine surgeon in all phases of care. A narrative literature review was performed to review difficulties in spine surgery on the obese patient population and techniques for mitigation. We specifically aimed to assess several topics with regard to this population: patient selection and preoperative care; intraoperative and surgical techniques; and postoperative care, outcomes, and complications. The literature review demonstrated that obese patients are at increased surgical risk with spine surgery due to a variety of factors at all stages of intervention. Preoperatively, obese patients have worse outcomes with physical therapy and present technical difficulties for injections. Transport to a hospital, imaging, resuscitation, and intubation are all challenged by increased body habitus. Intraoperatively, obese patients have increased operative times, blood loss, surgical site infections, and nerve palsies. Patient positioning and intraoperative imaging may be limited. Surgery itself may be technically challenging due to body habitus and minimally invasive techniques are becoming more prevalent in this population. Postoperatively, several studies demonstrate that obese patients have inferior outcomes compared with nonobese counterparts. Patient selection is a key for elective interventions, and appropriate infrastructure aids in the ultimate outcomes for both elective and nonelective surgical treatments. Overall, obese patients present several challenges to the spine surgeon, and certain precautions can be undertaken preoperatively, intraoperatively, and postoperatively to mitigate the associated risks to optimize outcomes.

Diversity in Orthopaedic Surgery: International Perspectives: AOA Critical Issues.

Orthopaedic surgery in the United States is one of the few medical specialties that has consistently lacked diversity in its training programs and workforce for decades, despite increasing awareness of this issue. Is this the case in other English-language speaking countries? Are there inherent national differences, or does orthopaedics as a profession dictate the diversity landscape around the globe?The Carousel group includes the presidents of the major English-language-speaking orthopaedic organizations around the globe-Australia, Canada, New Zealand, South Africa, the United Kingdom, and the United States. Established in 1952, members of this group attend each other's annual scientific meetings during the year of their presidency, learning about our profession in each country and building international relationships. In this article, 13 Carousel presidents from different countries explore diversity in orthopaedics in their training programs and the workforce, with an assessment of the current state and ideas for improvement.

Diversity in Orthopaedic Surgery: International Perspectives: AOA Critical Issues.

Orthopaedic surgery in the United States is one of the few medical specialties that has consistently lacked diversity in its training programs and workforce for decades, despite increasing awareness of this issue. Is this the case in other English-language speaking countries? Are there inherent national differences, or does orthopaedics as a profession dictate the diversity landscape around the globe?

The Effects of Perioperative Corticosteroids on Dysphagia Following Surgical Procedures Involving the Anterior Cervical Spine: A Prospective, Randomized, Controlled, Double-Blinded Clinical Trial.

BACKGROUND: Dysphagia is one of the most common complications of surgical procedures in the anterior cervical spine, and can persist up to 2 years postoperatively. Corticosteroids are relatively safe and inexpensive for treating various inflammatory conditions. Perioperative corticosteroid administration for anterior cervical spine procedures may effectively minimize postoperative dysphagia, potentially leading to better outcomes, decreased readmission rates, and improved patient satisfaction. The purpose of this study was to determine the efficacy of perioperative corticosteroids in decreasing the severity and duration of dysphagia following single-level and multilevel anterior cervical spine procedures. METHODS: Seventy-four patients undergoing elective anterior cervical surgical procedures for degenerative conditions were recruited. Patients with prior cervical procedures; with a diagnosis of fracture, malignancy, or infection; or requiring combined anterior-posterior procedures were excluded. Patients were randomized to perioperative intravenous dexamethasone or saline solution. Doses were administered before incision and at 8 and 16 hours postoperatively. Investigators and patients were blinded to the treatment throughout the study. Dysphagia outcomes were assessed with use of the Bazaz dysphagia scale and the Dysphagia Short Questionnaire (DSQ) at 1 day, 2 days, 1 week, 2 weeks, 1 month, 3 months, 6 months, and 12 months postoperatively. Statistical analysis was performed comparing means and standard deviations; significance was set at p < 0.05. Clinical outcomes were measured with use of the Quality of Life-12 and Neck Disability Index. RESULTS: Sixty-four patients were included in the analysis. There were 49 anterior cervical discectomies and fusions, 8 corpectomies, 1 hybrid procedure (corpectomy and adjacent discectomy), and 6 single-level arthroplasties. Patients who received corticosteroids had significantly better dysphagia scores on both the Bazaz scale and DSQ at most time points up to 6 months postoperatively (p < 0.05). On subgroup analysis, patients with multilevel (≥2-level) fusion benefited significantly from corticosteroids on both scales, whereas those with single-level procedures did not. There were no short-term wound complications or infections, and length of stay and fusion rates were comparable. CONCLUSIONS: Perioperative administration of corticosteroids can reduce dysphagia symptoms following multilevel anterior cervical procedures. Benefit was noted immediately and up to 6 months postoperatively. There was no significant effect on short-term wound-healing, infection rates, length of stay, or fusion rates. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Filling the Pipeline: AOA Critical Issues.

This is the Presidential Address, "Filling the Pipeline," that was given by Sanford E. Emery, MD, MBA, at the Annual Meeting of the American Orthopaedic Association in June 2016.

Novel rat tail discitis model using bioluminescent Staphylococcus aureus.

Management of spondylodiscitis is a challenging clinical problem requiring medical and surgical treatment strategies. The purpose of this study was to establish a rat model of spondylodiscitis that utilizes bioluminescent Staphylococcus aureus (S. aureus), thus permitting in vivo surveillance of infection intensity. Inocula of the bioluminescent S. aureus strain XEN36 were created in concentrations of 102 CFU/0.1 ml, 104 CFU/0.1 ml, and 106 CFU/0.1 ml. Three groups of rats were injected with the bacteria in the most proximal intervertebral tail segment. The third most proximal tail segment was injected with saline as a control. Bioluminescence was measured at baseline, 3 days, and weekly for a total of 6 weeks. Detected bioluminescence for each group peaked at day 3 and returned to baseline in 21 days. The average intensity was highest for the experimental group injected with the most concentrated bacterial solution (106 CFU/0.1 ml). Radiographic analysis revealed loss of intervertebral disc space and evidence of osseous bridging. Saline-injected spaces exhibited no decrease in intervertebral spacing as compared to distal sites. Histologic analysis revealed neutrophilic infiltrates, destruction of the annulus fibrosus and nucleus pulposus, destruction of vertebral endplates, and osseous bridging. Saline-injected discs exhibited preserved annulus fibrosus and nucleus pulposus on histology. This study demonstrates that injection of bioluminescent S. aureus into the intervertebral disc of a rat tail is a viable animal model for spondylodiscitis research. This model allows for real-time, in vivo quantification of infection intensity, which may decrease the number of animals required for infection studies of the intervertebral disc. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2075-2081, 2017.

Physician incentives for academic productivity. An analysis of orthopaedic department compensation strategies.

BACKGROUND: Changes in the health-care industry have led to increasing demand for physician-driven clinical volume. This environment has altered the traditional balance among teaching, research, and service responsibilities for faculty in residency training programs. As economic pressures mount and budgets shrink, academic departments are exploring ways of paying faculty that would help to maintain the global mission of the organization. The purpose of this study was to examine the compensation strategy for faculty in academic orthopaedic surgery departments in the United States with a focus on compensation methods for academic productivity. METHODS: Thirty-one academic orthopaedic surgery residency training programs were recruited for the study. Two methods of data collection were used: (1) a survey was mailed electronically to the program chairpersons or the finance directors, and (2) eight program leaders were interviewed to obtain more in-depth information regarding compensation for academic productivity in their organizations. RESULTS: All thirty-one programs responded to the survey. To compensate faculty for clinical productivity, twenty-two programs used a salary and bonus system, two used salary alone, and the remainder used combined methods. Nineteen departments had a compensation system that included academic productivity, and twelve did not. Of those that compensated for academic work, seven used the chair's decision, six used a point system, one used academic rank alone, and the remainder used a combination of methods. The point systems varied in breadth, focus, and amount of detail. CONCLUSIONS: Most, but not all, departments accounted for academic productivity in their compensation system. Most programs used the chair's discretion to determine academic bonuses, but several departments had developed point systems. There are common themes with regard to this issue, including the importance of the academic mission, the need for clinical revenues, the value of flexibility and transparency, and the importance of culture and leadership.

Changes in the iliac crest-lumbar relationship from standing to prone.

BACKGROUND CONTEXT: It is known that positioning patients on the Jackson and Andrews operative tables causes changes in lumbar lordosis and pelvic rotation. However, it is unknown if the relationship between the iliac crest and underlying lumbar levels, in particular the L4-L5 interspace, changes from standing to prone on these tables. PURPOSE: To assess the changes in the relationship between the iliac crests and lumbar spinal levels from standing to prone on two different operative positions using the Jackson and Andrews frames. STUDY DESIGN/SETTING: Comparative analysis of iliac crest position relative to spinal levels in the preoperative standing position and while positioned on the Jackson and Andrews frames. PATIENT SAMPLE: 48 randomly selected patients who underwent spinal surgery on either the Jackson or Andrews frame. OUTCOME MEASURES: Imaging. METHOD: Comparative measurements were made of the preoperative and intraoperative plain lateral lumbar radiographs. The location of the superior border of the iliac crest relative to the L4 lumbar spine level was compared between radiographs. RESULTS: Preoperatively, the iliac crest aligned with L4/L4-L5 spinal level in 79.2% of the 48 patients compared with 85.5% of intraoperative cases (p=.59). Intraoperative iliac crest level aligned with the L4/L4-L5 level in 80.8% and 90.9% of the patients on the Andrews and Jackson tables respectively (p=.43). Thirty-four patients (70.8%) demonstrated no change in iliac crest alignment between intraoperative and preoperative radiographs. There was a trend for the iliac crest to shift cephalad with operative positioning. CONCLUSION: Approximately 30% of patients demonstrated changes in the relationship between the iliac crest and lumbar levels between standing and positioning prone. The intraoperative position of the iliac crest aligned more accurately with the L4/L4-L5 spine level on the Jackson and Andrews frame compared with preoperative standing radiographs respectively. Further biomechanical studies should investigate the implication for lumbopelvic fixation.

Fracture of fusion mass after hardware removal in patients with high sagittal imbalance.

OBJECT: As spinal fusions become more common and more complex, so do the sequelae of these procedures, some of which remain poorly understood. The authors report on a series of patients who underwent removal of hardware after CT-proven solid fusion, confirmed by intraoperative findings. These patients later developed a spontaneous fracture of the fusion mass that was not associated with trauma. A series of such patients has not previously been described in the literature. METHODS: An unfunded, retrospective review of the surgical logs of 3 fellowship-trained spine surgeons yielded 7 patients who suffered a fracture of a fusion mass after hardware removal. Adult patients from the West Virginia University Department of Orthopaedics who underwent hardware removal in the setting of adjacent-segment disease (ASD), and subsequently experienced fracture of the fusion mass through the uninstrumented segment, were studied. The medical records and radiological studies of these patients were examined for patient demographics and comorbidities, initial indication for surgery, total number of surgeries, timeline of fracture occurrence, risk factors for fracture, as well as sagittal imbalance. RESULTS: All 7 patients underwent hardware removal in conjunction with an extension of fusion for ASD. All had CT-proven solid fusion of their previously fused segments, which was confirmed intraoperatively. All patients had previously undergone multiple operations for a variety of indications, 4 patients were smokers, and 3 patients had osteoporosis. Spontaneous fracture of the fusion mass occurred in all patients and was not due to trauma. These fractures occurred 4 months to 4 years after hardware removal. All patients had significant sagittal imbalance of 13-15 cm. The fracture level was L-5 in 6 of the 7 patients, which was the first uninstrumented level caudal to the newly placed hardware in all 6 of these patients. Six patients underwent surgery due to this fracture. CONCLUSIONS: The authors present a case series of 7 patients who underwent surgery for ASD after a remote fusion. These patients later developed a fracture of the fusion mass after hardware removal from their previously successfully fused segment. All patients had a high sagittal imbalance and had previously undergone multiple spinal operations. The development of a spontaneous fracture of the fusion mass may be related to sagittal imbalance. Consideration should be given to reimplanting hardware for these patients, even across good fusions, to prevent spontaneous fracture of these areas if the sagittal imbalance is not corrected.

A Comparison of Open and Percutaneous Techniques in the Operative Fixation of Spinal Fractures Associated with Ankylosing Spinal Disorders.

BACKGROUND: The operative care of patients with ankylosing spinal conditions such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) after a spine fracture is not well represented in the literature. This work seeks to determine the effect of minimally invasive techniques on patients with spinal fractures and ankylosing spinal conditions through a retrospective case-control analysis. METHODS: The operative logs from 1996-2013 of seven fellowship-trained spine surgeons from two academic, Level I trauma centers were reviewed for cases of operatively treated thoracic and lumbar spinal fractures in patients with ankylosing spinal disorders. RESULTS: A total of 38 patients with an ankylosing spinal condition and a spinal fracture were identified. The minimally invasive group demonstrated a statistically significant decrease in estimated blood loss, operative time, and need for transfusion when compared to either the hybrid or open group. There was no difference between the three subgroups in overall hospital stay or mortality. CONCLUSIONS: Patients with ankylosing spinal conditions present unique challenges for operative fixation of spinal fractures. Minimally invasive techniques for internal fixation offer less blood loss, operative time, and need for transfusion compared to traditional techniques; however, no difference in hospital stay or mortality was reflected in this series of patients. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: Ankylosing spinal disorders are increasingly common in an aging population.

Improvement of Segmental Lordosis in Transforaminal Lumbar Interbody Fusion: A Comparison of Two Techniques.

Study Design Retrospective review. Objective The purpose of this study was to determine the radiographic impact of a transforaminal lumbar interbody fusion (TLIF) versus a cantilever TLIF technique on segmental lordosis, segmental coronal alignment, and disk height. Methods A retrospective review was done of all patients undergoing TLIF procedures from 2006 to 2011 by three spine surgeons. Traditional TLIF versus cantilever TLIF results were compared, and radiographic outcomes were assessed. Results One hundred one patients were included in the study. Patients undergoing the cantilever TLIF procedure had a significantly greater change in segmental lordosis and disk height compared with those who underwent the traditional procedure (p > 0.0001). Conclusions The cantilever TLIF technique can lead to greater change in segmental lordosis based upon radiographic outcomes.

Ossification of the posterior longitudinal ligament. Results of anterior cervical decompression and arthrodesis in sixty-one North American patients.

BACKGROUND: Ossification of the posterior longitudinal ligament is commonly associated with cervical myelopathy. Surgical treatment is a matter of controversy. We report on a series of patients who were managed with anterior cervical decompression and arthrodesis for the treatment of cervical myelopathy associated with ossification of the posterior longitudinal ligament. METHODS: We retrospectively reviewed the records for all sixty-five patients who had been managed with anterior decompression and arthrodesis for the treatment of cervical ossification of the posterior longitudinal ligament and associated neurologic compression from 1982 to 2001. Sixty-one patients (thirty-nine men and twenty-two women) were followed for at least two years (or until the time of death). The average number of vertebrae resected was 2.2. The average duration of follow-up for the sixty surviving patients was four years (range, two years to fifteen years and four months). The preoperative, six-week postoperative, and final follow-up clinical status (including neurological function as assessed with the Nurick grading system) was recorded for each patient. RESULTS: Fifty-six of the sixty-one patients had neurological improvement, with an average improvement of 1.5 Nurick grades at the time of the final follow-up. Eight patients had absent dura at the time of surgery and, of these, five had development of a cerebrospinal fluid fistula. Eight patients had development of new neurological signs and/or symptoms in the upper extremity postoperatively. Eight patients required reoperation because of a painful pseudarthrosis (one patient), strut-graft dislodgment (three), cerebrospinal fluid leakage (three), or compression of a nerve root caudad to the area of the original procedure (one). One patient died as the result of cardiac arrest on the third postoperative day. Fifty-eight patients had an osseous fusion, one had an asymptomatic nonunion, and one had a symptomatic pseudarthrosis that was treated with revision surgery. CONCLUSIONS: Anterior decompression and arthrodesis is an effective way to achieve pain relief and neurological improvement in North American patients of non-Asian descent who have cervical myelopathy associated with ossification of the posterior longitudinal ligament. The risk of durocutaneous fistula, graft dislodgment, and postoperative neurological symptoms appears to be high in patients with cervical myelopathy associated with this condition.

Effect of Head Position on Intraocular Pressure During Lumbar Spine Fusion: A Randomized, Prospective Study.

BACKGROUND: Ischemic optic neuropathy resulting in visual loss is a rare but devastating complication of spine surgery. Elevated intraocular pressure (IOP) results in decreased perfusion and possibly ischemic optic neuropathy. We performed a randomized, prospective trial to evaluate the effect of head positioning on IOP during lumbar spine fusion. METHODS: The study included fifty-two patients treated at one institution. Inclusion criteria were a lumbar spine fusion and an age of eighteen to eighty years. Exclusion criteria were a diagnosis of tumor, infection, or traumatic injury or a history of eye disease, ocular surgery, cervical spine surgery, chronic neck pain, or cervical stenosis. The control group underwent the surgery with the head in neutral and the face parallel to the level operating room table whereas, in the experimental group, the neck was extended so that the face had a 10° angle of inclination in relation to the table. IOP measurements were recorded along with the corresponding blood pressure and PCO2 values at the same time points. The primary outcome measure was the change in intraocular pressure (ΔIOP, defined as the maximum IOP minus the initial IOP). RESULTS: Analysis of covariance (ANCOVA) was used for categorical risk factors, and regression analysis was used for continuous risk factors. The mean ΔIOP, corrected for duration of surgery, was significantly (p = 0.0074) lower in the group treated with the head elevated than it was in the group treated with the head in neutral (difference between the two groups, 4.53 mm Hg [95% confidence interval, 1.29 to 7.79 mm Hg]). No patient sustained visual loss or any cervical-spine-related complications. CONCLUSIONS: Head elevation for adult lumbar spine fusion performed with the patient prone resulted in significantly lower IOP measurements than those seen when the operation was done with the patient's head in neutral. As lower IOP correlates with increased optic nerve perfusion, this intervention could mitigate the risk of perioperative blindness after spine surgery done with the patient prone.