Faculty Bibliography

Study Design/UNASSIGNED:Retrospective case series with prospective arm. Purpose/UNASSIGNED:To assess the safety and accuracy of percutaneous lumbosacral pedicle screw placement (PLPSP) in the lumbosacral spine using intraoperative dual-planar fluoroscopy (DPF). Overview of Literature/UNASSIGNED:There are several techniques available for achieving consistent, safe, and accurate results with PLPSP. There is a paucity of literature describing the beneficial operative, economic, and clinical outcomes of DPF, the most readily accessible image guidance system. Methods/UNASSIGNED:From 2004 to 2014, 451 consecutive patients underwent PLPSP using DPF, for a total of 2,345 screw placement. The results of prospectively obtained postoperative computed tomography (CT) examinations of an additional 41 consecutive patients were compared with the results of 104 CT examinations obtained postoperatively due to clinical symptomatology; these results were interpreted by three reviewers. The rates of revision indicated by misplaced screws with consistent clinical symptomatology were compared between groups. Pedicle screw placement was graded according to 2-mm increments in medial pedicle wall breach and measurement of screw axis placement. Results/UNASSIGNED:Seven of the 2,345 pedicle screws placed percutaneously with the use of the dual-planar fluoroscopic technique required revision because of a symptomatic misplaced screw, for a screw revision rate of 0.3%. There were no statistically significant demographic differences between patients who had screws revised and those who did not. All screws registered greater than 10 mA on electromyographic stimulation. In the 41 prospectively obtained CT examinations, one out of 141 screws (0.7%) was revised due to pedicle wall breach; whereas among the 104 patients with 352 screws, three screws were revised (0.9%). Conclusions/UNASSIGNED:DPF is an extremely accurate, safe, and reproducible technique for placement of percutaneous pedicle screws and is a readily available and cost-effective alternative to CT-guided pedicle screw placement techniques. Postoperative CT evaluation is not necessary with PLPSP unless the patient is symptomatic. Acceptable electromyographic thresholds may need to be reevaluated.

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.

STUDY DESIGN/METHODS:This is a epidemiological database analysis. OBJECTIVES/OBJECTIVE:The objectives of this article are to assess the following characteristics of vertebral osteomyelitis (VO): (1) incidence and patient demographics, (2) mortality rate, (3) length-of-stay (LOS), and (4) admission costs. SUMMARY OF BACKGROUND/BACKGROUND:VO is a serious disease with potentially devastating clinical consequences. At present, there is limited data on the epidemiology of VO in the United States as previous reports are based on older studies with small sample sizes. METHODS:We used the Nationwide Inpatient Sample database and estimated that 228,044 patients were admitted for VO in the United States between 1998 and 2013. Data were extracted on patient demographics, comorbidities, inpatient mortality, LOS, and inflation-adjusted hospitalization charges. Multivariable regression analyses were performed. RESULTS:The incidence of VO admission was 4.8 per 100,000, increasing from 8021 cases (2.9/ 100,000) in 1998 to 16,917 cases (5.4/100,000) in 2013. Majority of patients were white (74%), male (51%), younger than 59 years of age (49.5%), and carried Medicare insurance (50%). The increase in incidence for male and females was similar. The mortality rate during hospital stay was 2.1%, decreasing from 2% in 1998 to 1.7% in 2006 and increasing to 2.2% in 2013. Risk factors for mortality included increased age, male sex, and higher comorbidity score. History of congestive heart failure [odds ratio (OR)=2.45], cerebrovascular disease (OR=1.92), liver disease (OR=2.33), hepatitis C (OR=2.36), and renal disease (OR=1.88) was associated with higher mortality rate. Mean LOS was 9.2 days, decreasing from 9.1 days in 1998 to 8.8 days in 2013. The mean estimated hospital charges for admission were $54,599, however, this increased from $24,102 in 1998 (total of $188.8 millions) to $80,786 in 2013 (total of $1.3 billions). CONCLUSION/CONCLUSIONS:This condition is associated with lengthy and expensive hospital stays resulting in a significant burden to patients and the health care system.

Little literature exists examining differences in presentation and outcomes between monomicrobial and polymicrobial vertebral infections. Seventy-nine patients treated for vertebral osteomyelitis between 2001 and 2011 were reviewed. Patients were divided into monomicrobial and polymicrobial cohorts based on type of infection. Various characteristics were compared between the 2 groups. The 26 patients with a polymicrobial infection were older and had a higher mortality rate, lower clearance of infection, larger infection, more vertebral instability, higher erythrocyte sedimentation rate at presentation, and longer mean length of stay. There were no significant differences in Oswestry Disability Index scores at final follow-up, but there were differences in presentation and clinical outcomes between monomicrobial and polymicrobial vertebral osteomyelitis. Patients may benefit from counseling regarding their disease type and potential prognosis. [Orthopedics. 2017; 40(2):e370-e373.].

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has been shown to have long-term clinical outcomes similar to those with open TLIF and decreased perioperative morbidity. This study assessed whether this procedure can be safely performed in outpatient settings. Ninety-six consecutive patients undergoing 1- or 2-level MIS-TLIFs were retrospectively reviewed. They were divided into inpatient and outpatient cohorts (36%). All had a minimum of 2 years of follow-up. Patient demographics, comorbidities, complications, and readmissions were examined. Early postoperative complications were stratified into wound related, infection, neurologic, implant related, and vascular injuries. Patients in the outpatient cohort were significantly younger, had lower American Society of Anesthesiologists physical status scores, and had lower Charlson Comorbidity Index scores than patients in the inpatient cohort. There were no statistically significant differences in overall postoperative complication rates, readmission rates, or final Oswestry Disability Index or visual analog scale scores between the 2 cohorts. The clinical outcomes of the outpatient TLIF procedure were similar to those of the inpatient procedure and it had an acceptable complication rate. [Orthopedics. 2016; 39(6):e1218-e1222.].

Paraspinal muscles are commonly affected during spine surgery. The purpose of this study was to assess the potential factors that contribute to paraspinal muscle atrophy (PMA) after lumbar spine surgery. A comprehensive review of the available English literature, including relevant abstracts and references of articles selected for review, was conducted to identify studies that reported PMA after spinal surgery. The amount of postoperative PMA was evaluated in (1) lumbar fusion vs nonfusion procedures; (2) posterior lumbar fusion vs anterior lumbar fusion; and (3) minimally invasive (MIS) posterior lumbar decompression and/or fusion vs non-MIS equivalent procedures. In total, 12 studies that included 529 patients (262 men and 267 women) were reviewed. Of these, 365 patients had lumbar fusions and 164 had lumbar decompressions. There was a significantly higher mean postoperative volumetric PMA with fusion vs nonfusion procedures (P=.0001), with posterior fusion vs anterior fusion (P=.0001), and with conventional fusions vs MIS fusions (P=.001). There was no significant difference in mean volumetric lumbar PMA with MIS decompression vs non-MIS decompression (P=.56). There was significantly higher postoperative PMA with lumbar spine fusions, posterior procedures, and non-MIS fusions. [Orthopedics.].

STUDY DESIGN/METHODS:Retrospective clinical cohort study. OBJECTIVE:To compare the long-term complications and outcomes scores of primary and revision surgeries for adult spinal deformity of patients treated with long fusions to the sacrum. SUMMARY OF BACKGROUND DATA/BACKGROUND:Long fusions in patients with adult spinal deformity are fraught with complications and the need for reoperation that can significantly impact patient health-related quality of life. METHODS:Data from 134 consecutive patients who underwent spinal fusion from the thoracic spine to the sacropelvis and had a minimum of 5-year follow-up were analyzed. Patients were classified as primary surgery (PS) and index revision (IR) surgery; they were then subdivided based on whether they returned to the operating room (RTO) or not (NRTO). RTO complications were classified as 1) infection, 2) neurologic, 3) fusion status, 4) implants, and 5) global alignment and stratified as <6 months, <2 years, and >2 years. Final Scoliosis Research Society Patient Questionnaire (SRS 22r) and Oswestry Disability Index (ODI) scores were compared between subgroups. RESULTS:Seventy-one PS and 63 IR were included in the analysis. Mean age at surgery was 54.9 years (30-78), mean follow-up 5.8 years (4.9-12.8). RTO rates were 21.1% and 34.9%, respectively, for PS and IR (p = .16). 43.8% of patients requiring reoperation did so on multiple occasions. Fifty PS and 41 IR cases had complete SRS 22 and ODI scores. Final SRS 22 total scores were 3.74 and 3.41 (p = .02) for the respective groups. ODI scores were 25.4% and 34.0% (p = .02). CONCLUSIONS:Both groups had a significant number of revision surgeries performed by 5 years of follow-up. Unplanned reoperation significantly affected ODI and SRS 22 outcomes scores in the individual domains of pain, function, and overall satisfaction as well as total score at the 5-year follow-up regardless of PS or IR status. Overall, the PS group had improved outcomes when compared to the IR group.

Vertebral compression fractures are a significant source of morbidity and mortality among patients of all age groups. These fractures result in both acute and chronic pain. Patients who sustain such fractures are known to suffer from more comorbidities and have a higher mortality rate compared with healthy people in the same age group. In recent years, balloon kyphoplasty has become a popular method for treating vertebral compression fractures. However, as longer-term follow-up becomes available, the effects of cement augmentation on adjacent spinal segments require investigation. Here, we have performed a retrospective chart review of 258 consecutive patients with pathologic vertebral compression fractures secondary to osteoporosis, treated by either conservative measures or balloon kyphoplasty with polymethylmethacrylate cement augmentation. Multivariate analysis of patient comorbidities was performed to assess the risks associated with subsequent adjacent and remote compression fracture at a minimum of 2 years follow-up. A total of 258 patients had 361 vertebral compression fractures. A total of 121 patients were treated nonoperatively and 137 underwent balloon kyphoplasty with polymethylmethacrylate cement augmentation. The mean follow-up for both cohorts was 2.7 years (range, 2-6 years). The kyphoplasty cohort was significantly older than the nonoperative cohort (mean age, 78.5 versus 74.2 years; p = 0.02), had 24 more patients with diabetes mellitus (37 versus 13; p = 0.05), and had 34 more patients with a history of smoking (50 versus 16; p = 0.05). However, the kyphoplasty cohort had less patients with a history of non-steroidal anti-inflammatory drug (NSAID) use (45 versus 71; p = 0.07). There were no demographic differences between groups in patients with secondary fractures. Nonoperative treatment was identified as a statistically significant independent risk factor for subsequent vertebral compression fracture [odds ratio (OR), 2.28]. Univariate analysis identified age, diabetes mellitus, smoking, NSAID usage, and female gender as risk factors for subsequent vertebral compression fracture. When adjusted for multivariate analysis, no individual factor demonstrated increased risk for subsequent fracture. Patients diagnosed with vertebral compression fractures secondary to osteoporosis suffer from multiple medical comorbidities. No particular comorbidity was identified as solely attributable for increased risk of subsequent remote or adjacent compression fractures. Patients in this series treated with nonoperative (conservative) management had a 2.28 times greater risk for a subsequent vertebral compression fracture than patients treated with balloon kyphoplasty and polymethylmethacrylate cement augmentation.