Faculty Bibliography

BACKGROUND CONTEXT/BACKGROUND:Obese patients can pose significant challenges to spine surgeons in lumbar fusion procedures. The increased risk of complications has led surgeons to be wary in pursing operative interventions in these patients. Since the advent of minimally-invasive techniques in lumbar fusion, surgeons are turning to these procedures in an attempt to minimize operative time, blood loss and overall cost. With an increased proportion of obese patients in the population, it is imperative to understand the long-term outcomes in these minimally-invasive approaches. PURPOSE/OBJECTIVE:The purpose of this study was to evaluate the long-term safety and efficacy of extreme lateral interbody fusion (XLIF) in the obese. STUDY DESIGN/SETTING/METHODS:Retrospective Cohort Study. PATIENT SAMPLE/METHODS:115 patients (53 non-obese and 62 obese) who underwent XLIF with a minimum of 5-year follow-up. OUTCOME MEASURES/METHODS:). Functional outcomes were assessed by comparing pre- and postoperative VAS and ODI scores. Reoperation rates were compared between cohorts. PI-LL mismatch was calculated from both pre- and postoperative radiographs. Rates of graft subsidence and fusion were measured at final follow-up. RESULTS:115 consecutive patients were included (53 non-obese & 62 obese) with a mean follow up of 95.3 months. Mean BMI was 25.3 in the non-obese group and 35.3 in the obese group (p<0.001). There were more females in non-obese cohort. VAS scores decreased by a mean of 5.7 in the non-obese cohort, and 5.4 in the obese cohort (p=0.213). ODI improvement was also similar between the groups. 5.6% of non-obese patients required reoperation compared to 9.6% of obese patients (p=0.503). Graft subsidence rates at final follow-up were 5.66% and 8.06% for the non-obese and obese groups, respectively (p= 0.613). Rates of successful fusion were 96.23% and 98.39% for the non-obese and obese groups, respectively (p= 0.469). Both cohorts achieved a similar proportion of PI-LL mismatch correction, 85% in obese vs 78% in non-obese patients (p=0.526). CONCLUSION/CONCLUSIONS:Obese patients have similar surgical outcomes to non-obese patients with respect to functional outcome scores, reoperation rates, graft subsidence and correction of PI-LL mismatch after long-term follow-up. With similar outcome and reoperation profiles, minimally-invasive approaches to the spine, such as XLIF, may be an acceptable alternative to traditional open procedures in obese patients.

Study Design/UNASSIGNED:Retrospective cohort study. Purpose/UNASSIGNED:To assess long-term clinical outcomes of adjacent segment disease (ASD) in patients who underwent lumbar interbody fusion with percutaneous pedicle screw (PS) instrumentation. Overview of Literature/UNASSIGNED:ASD is a well-known sequela of spinal fusion, and is reported to occur at a rate of 2%-3% per year. There is debate as to whether ASD is a result of the instrumentation and fusion method or is the natural history of the patient's disease. Minimally invasive percutaneous PS augmentation of lumbar interbody fusion aims to prevent the disruption of posterior soft tissue stabilizers. Methods/UNASSIGNED:From 2004-2014, 419 consecutive patients underwent anterior, lateral, or minimally invasive transforaminal lumbar interbody fusion with percutaneous PS placement at a single institution. The mean follow-up was 4.5 years. The primary outcome measure was reoperation due to ASD. Patients were divided into two cohorts: those who underwent revision surgery secondary to ASD and those who did not require further surgery. Radiographic parameters were performed using postoperative radiographs. Patients with a pelvic incidence-lumbar lordosis (PI-LL) mismatch >10° were noted. Results/UNASSIGNED:Revision proportion secondary to ASD was 4.77% (n=20). Mean time to revision surgery was 2.5 years. Revision rate secondary to ASD was 1.1% per year. Patients who developed ASD were younger than those who did not (50.5 vs. 56.9 years, p=0.015). There was no difference in number of levels fused between cohorts. Revision proportion secondary to ASD was similar between approaches (anterior, lateral, minimally invasive). There was no significant difference in PI-LL mismatch between those who underwent revision for ASD and those who did not (22.2% vs 18.8%, p=0.758). Conclusions/UNASSIGNED:ASD rates in patients who underwent percutaneous PS placement were lower than those previously published after open PS placement, possibly related to greater preservation of the posterior stabilizing elements of the lumbar spine.

While extragonadal seminomas resulting in spinal cord compression are rarely reported in the literature, most have been treated with surgical decompression followed by radiation therapy. In this report, we present the unique and interesting case of a 38-year-old man who initially presented as an outpatient with a chief complaint of axial neck pain and lateral thoracic wall pain. After an extensive malignancy workup, he was diagnosed with a primary cervical spine seminoma and was treated with a C6-T1 laminectomy with posterior spinal instrumentation from C5 to T2. He has since undergone chemotherapy with cisplatin, vinblastine, and bleomycin, and at 24-month follow-up, he remains asymptomatic with no signs of recurrent disease.

OBJECTIVE:Achieving fusion at the lumbosacral junction poses many technical challenges. No data exist in the literature comparing radiographic or clinical outcomes between the different surgical techniques of transsacral fixation (TSF) with rods and transforaminal lumbar interbody fusion (TLIF) in conjunction with iliac fixation. The purpose of this study was to compare the clinical outcomes and radiographic fusions of TSF to TLIF in patients with adult spinal deformity undergoing long fusions across the lumbosacral junction. METHODS:Patients with primary adult spinal deformity who underwent long fusions from the thoracic spine across the lumbosacral junction with different approaches of interbody fusion at the L5-S1 level were reviewed. Patients were subdivided by approach (TSF vs TLIF). Fusion status at L5-S1 was evaluated by multiple radiographs and/or CT scans. Scoliotic curve changes were also evaluated preoperatively and at final follow-up. Clinical outcomes were assessed by Scoliosis Research Society Outcome Instrument 22 and Oswestry Disability Index scores. RESULTS:A total of 36 patients were included in the analysis. There were 18 patients in the TSF group and 18 patients in the TLIF group. A mean of 14.00 levels were fused in the TSF group and 10.94 in the TLIF group (p = 0.01). Both groups demonstrated significant postoperative radiographic improvement in coronal parameters. The fusion rates for TSF and TLIF groups were 100% and 88.9%, respectively (p < 0.05). Eight patients in the TSF group had pelvic fixation with unilateral iliac screws, compared to 15 patients in the TLIF group (p = 0.015). No statistical differences in patients' reported outcomes were seen between groups. CONCLUSIONS:Despite similar clinical and radiographic outcomes between both groups, TSF required fewer iliac screws to augment stability of the lumbosacral junction while achieving a higher rate of fusion. This study suggests that TSF may decrease potential instrument-related complications requiring revision while decreasing operating room time and implant-related costs.

STUDY DESIGN/UNASSIGNED:Retrospective cohort study. OBJECTIVES/UNASSIGNED:To evaluate the impact of computed tomography angiography (CTA) in the management of trauma patients with cervical spine fractures by identifying high-risk patients for vertebral artery injury (VAI), and evaluating how frequently patients undergo subsequent surgical/procedural intervention as a result of these findings. METHODS/UNASSIGNED:All trauma patients with cervical spine fractures who underwent CTA of the head and neck at our institution between January 2013 and October 2017 were identified. Patients were indicated for CTA according to our institutional protocol based on the modified Denver criteria, and included patients with cervical fractures on scout CT. Those with positive VAI were noted, along with their fracture location, and presence or absence of neurological deficit on physical examination. Statistical analysis was performed and odds ratios were calculated comparing the relationship of cervical spine fracture with presence of VAI. RESULTS/UNASSIGNED:= .007). Of the 25 who had a VAI, 9 were unable to undergo reliable neurologic examination. Of the remaining 16 patients, 5 (31.3%) had motor or sensory deficits localized to the side of the VAI, with no other attributable etiology. CONCLUSIONS/UNASSIGNED:Cervical spine fractures located in the region of the C1-C3 vertebrae were more likely to have an associated VAI on CTA. VAI should also be considered in cervical trauma patients who present with neurological deficits not clearly explained by other pathology. Despite a finding of VAI, patients rarely underwent subsequent surgical or procedural intervention.

As a consultant, the orthopaedic spine surgeon is often asked to evaluate patients with acute-onset extremity weakness. In some cases, patient's deficits can be attributed to nonspinal pathology; therefore, it is important to be aware of nonorthopaedic diagnoses when evaluating these patients. We report a case of thyrotoxic periodic paralysis that was initially confused by the consulting service with spinal pathology. A 32-year-old Hispanic man presented to our emergency department with rapid onset of lower extremity weakness. The consulting team ordered CT of the cervical and lumbar spine, as well as MRI of the lumbar spine which was aborted due to the patient's worsening tachycardia and chest pain. The spine service was subsequently consulted to evaluate the patient. Review of the metabolic panel revealed a low potassium, and additional testing led to the eventual diagnosis of thyrotoxic periodic paralysis. After correction of the patient's potassium, his weakness rapidly resolved, and no additional spinal workup was pursued. We describe this patient's presentation and outline the differential diagnosis for acute, nontraumatic extremity weakness, including both orthopaedic and other medical causes, that the spine surgeon should be aware of when evaluating patients with extremity weakness.

Rotator cuff tear (RCT) and cervical spinal stenosis (CSS) are common pathologies in the elderly. Both conditions may present with lateral shoulder pain and weakness or numbness of the upper extremity, potentially affecting patients' ability to live independently. Few data are available on the incidence of CSS among patients with concurrent RCT. The purpose of this study was to investigate the incidence of CSS among RCT patients, demographics, and surgical management using a national insurance database. The Medicare database was used to identify patients with RCT and concomitant CSS by ICD-9 codes from 2005-2014. Trends based on age, gender, and body mass index (BMI) were assessed. Utilization of open and arthroscopic rotator cuff repair (RCR) was compared. A total of 86,501 patients were identified. The number of patients diagnosed with RCT and CSS significantly increased (p< 0.0001). The incidence of CSS in patients with RCT increased from 9% to 13% (p < 0.05). Females < 64 years were more likely to exhibit combined pathology than age-matched males (OR 1.15, 95% CI 1.12 to 1.18) or females > 65 years (OR 1.64, 96% CI 1.61 to 1.67). A BMI of 30-40 kg/m2 demonstrated the highest incidence (43%, p < 0.0001). Arthroscopic RCR increased by 2% (p = 0.03) in RCT-CSS. The incidence of CSS in RCT patient is increasing. Orthopedic surgeons should maintain high clinical suspicion for concurrent CSS pathology in patients with RCT, particularly in obese female patients > 65 years with several medical comorbidities. Further investigation into the influence of these concurrent pathologies on patient outcomes is warranted.

Clinical care of patients with unstable thoracolumbar vertebral body fractures may be challenging, especially in the setting of polytrauma patients who require other acute intervention. Compared with the traditional open approach, percutaneous short-segment fixation constructs place less surgical burden on patients regarding operative time and blood loss. Between 2008 and 2012, 32 patients with a mean age of 49 years (range, 19-80 years) underwent percutaneous short-segment fixation at the authors' institution and had a minimum of 6 months of complete clinical and radiographic follow-up. Load-sharing classification scores were determined. Outcomes evaluated included anterior body height, posterior body height, local kyphosis, regional kyphosis, thoracolumbar junctional kyphosis, mean operative time, and total blood loss. Standard binomial and categorical comparative analyses were performed. All load-sharing classification scores were 7 or less, and 11 of the 32 patients were polytrauma patients requiring surgery. No difference was seen between preoperative and late measurements of anterior body height, posterior body height, local kyphosis, regional kyphosis, or thoracolumbar junctional kyphosis. There were no complications, revisions, or anterior corpectomies. Only 2 patients (6%) underwent elective removal of hardware at 1 year. Mean operative time was 43 minutes (range, 33-56 minutes), and mean estimated blood loss was less than 50 mL. Percutaneous short-segment fixation prevented loss of vertebral body height and progression of kyphosis in the treatment of unstable thoracolumbar fractures with load-sharing classification scores of 7 or less. This study shows that these fractures with a load-sharing classification score of 6 and 7 may be stabilized using fewer screws than traditional methods in some patients and allow polytrauma patients to undergo other acute treatment. [Orthopedics. 201x; xx(x):xx-xx.].

BACKGROUND:Several studies have sought to address the role of routine preoperative MRI in patients with adolescent idiopathic scoliosis (AIS) undergoing deformity correction. Despite similar results regarding the prevalence of neuraxial anomalies detected on MRI, published conclusions conflict and give opposing recommendations. Lack of consensus has led to important variations in use of MRI before spinal surgery for patients with AIS. QUESTIONS/PURPOSES/OBJECTIVE:This systematic review and meta-analysis of studies about patients with AIS evaluated (1) the overall proportion of neuraxial abnormalities; (2) the patient factors and curve characteristics that may be associated with abnormalities; and (3) the proportion of patients who underwent neurosurgical intervention before scoliosis surgery and the kinds of neuraxial lesions that were identified. METHODS:We performed a search of four electronic databases (PubMed, EMBASE, CINAHL Plus, and SCOPUS) utilizing search terms related to routine MRI and AIS, yielding 206 articles. Studies included had at least 20 participants, patients with ages 11 to 21 years, and a Methodological Index for Non-Randomized Studies (MINORS) study quality score of 8 and 16 points for noncomparative and comparative studies, respectively. Non-English manuscripts, animal studies, and those that did not include patients with AIS solely were excluded. Eighteen articles with 4746 patients were included for analysis of the overall proportion of neuraxial abnormalities, 12 articles with 3028 patients for analysis by sex, eight articles with 1603 patients for right main thoracic curve, eight articles with 665 patients for a left main thoracic curve, and 13 articles with 3063 patients and 230 (7.5%) abnormalities for number of neurosurgical interventions before scoliosis correction. The mean MINORS score for studies included was 14 (range, 10-20). Each study was analyzed for the proportion of patients identified with neuraxial abnormalities and associations with specific demographics. We determined the proportion of patients who underwent surgical interventions before scoliosis surgery as well as the types of neuraxial lesions identified. The articles were assessed for heterogeneity and publication bias. Because all groups were determined to be heterogeneous, a random-effects model was used for each group in this meta-analysis; with this analysis, an overlap of 95% confidence intervals suggests no difference at the p < 0.05 level, but this analytic approach does not provide p values. RESULTS:The pooled proportion of neuraxial abnormalities detected on MRI was 8% (95% confidence interval [CI], 6%-12%). With the numbers available, we found no difference in the proportion of male and female patients with neuraxial abnormalities (18% [95% CI, 11%-29%] versus 9% [95% CI, 6%-12%], respectively). Likewise, there was no difference in the proportion of pooled neuraxial abnormalities in right and left curves (9% [95% CI, 6%-14%] versus 15% [95% CI, 5%-35%], respectively). In the subset of abnormalities analyzed for number of neurosurgical interventions before scoliosis correction, the pooled proportion showed that 33% (95% CI, 24%-43%) underwent neurosurgical intervention before deformity correction. The most common abnormalities of the 367 found on MRI were syringomyelia in 127 patients (35%), Arnold-Chiari Type 1 malformation with syrinx in 103 patients (28%), and isolated Arnold-Chiari Type 1 malformation in 91 patients (25%). CONCLUSIONS:The proportion of patients with AIS who have neuraxial abnormalities is high (8%) and a large number undergo surgical intervention before scoliosis reconstruction. We did not find any particular demographic variables that indicated an increased risk of abnormality. Clinicians should consider advanced imaging before surgical intervention in the treatment of a patient with an idiopathic diagnosis. Preventable variables need to be identified by future studies to establish a better working treatment protocol for these patients. LEVEL OF EVIDENCE/METHODS:Level III, diagnostic study.