Frailty Is Predictive of Adverse Postoperative Events in Patients Undergoing Lumbar Fusion

STUDY DESIGN

Retrospective study of prospectively collected data.

OBJECTIVE

To analyze the modified frailty index (mFI) as a predictor of adverse postoperative events following posterior lumbar fusion.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database including all adult patients undergoing posterior lumbar interbody fusion or transforaminal lumbar interbody fusion between 2005 and 2012. Outcomes measured included mortality, postoperative complications, length of stay, reoperations, and readmissions. The previously described mFI was calculated, and univariate and multivariate logistic regression analysis were used to analyze risk factors associated with morbidity, mortality, and adverse postoperative events. This study was qualified as exempt by the Mount Sinai Hospital Institutional Review Board.

RESULTS

A total of 6094 patients met inclusion criteria. The mean mFI was 0.087(0-0.545). Increasing mFI score was associated with increased complications, reoperations, prolonged length of stay (LOS), and morbidity (P < .05). As the mFI score increased from 0.27 (3/11 variables present) to ≥0.36 (4/11), the rate of any complication increased from 26.8% to 35% (P < .0001), sepsis 2.4% to 5.2% (P < .0001), wound complications 4.4% to 6.5% (P < .0001), unplanned readmissions 4.7% to 20% (P = .02), and urinary tract infection 4.1% to 10.4% (P < .0001). An mFI of ≥0.36 was an independent predictor of any complication (odds ratio [OR]= 2.2, 95% confidence interval [CI] = 1.3-3.7), sepsis (OR = 6.3, 95%, CI = 1.8-21), wound complications (OR = 2.9, 95% CI = 1.1-8.2), prolonged LOS (OR = 2.3, 95% CI = 1.4-3.7), and readmission (OR = 4.3, 95% CI = 1.5-12.7).

CONCLUSION

Patients with higher mFI scores (≥ 4/11 variables) are at a significantly higher risk of major complications, readmissions, and prolonged LOS following lumbar fusion.

Absent congenital cervical pedicle nearly misdiagnosed as a facet dislocation: A case report

Background

Cervical spinal injury encompasses up to 1.5% of all pediatric injuries. Children, and more specifically infants, are a difficult subset of patients to obtain neurological exam in the setting of trauma, thus necessitating the use of cervical X-rays, CT scans, and MRI imaging.

Case description

A healthy, 15-month-old boy had an unwitnessed fall down a flight of stairs and received a CT scan of the head and cervical spine in the emergency department due to cephalohematoma and mechanism of injury. The patient was initially diagnosed with a unilateral facet dislocation but after additional imaging and rigorous interdisciplinary discussions, the patient was correctly diagnosed with a congenitally absent left C5 pedicle. Surgical intervention was not pursued and the patient was discharged home with close follow up.

Conclusion

In the acute trauma setting, congenital absent cervical pedicle can be difficult to differentiate from unilateral facet dislocation and may require the use of advanced imaging and close communication between the neurosurgery and radiology departments. Given the high morbidity and mortality involved in the repair of facet dislocation in a child, it is crucial to maintain high degree of clinical suspicion for absent spinal pedicle. In this case, the patient nearly underwent surgical intervention, but was ultimately able to be discharged home with no symptoms or deficits after correct diagnosis.

Incidence, Impact, and Risk Factors for 30-Day Wound Complications Following Elective Adult Spinal Deformity Surgery

STUDY DESIGN

Case-control study.

OBJECTIVE

To determine the incidence, impact, and risk factors for wound complications within 30 days following elective adult spinal deformity surgery.

METHODS

Current Procedural Terminology and International Classification of Diseases, Ninth Edition, diagnosis codes were used to query the database for adults who underwent spinal deformity surgery from 2010 to 2014. Patients were separated into groups of those with and without wound complications. Univariate analysis and multivariate logistic regression were used to analyze the influence of patient factors, operative variables, and clinical characteristics on the incidence of postoperative wound complication. This study was qualified as exempt by the Mount Sinai Hospital Institutional Review Board.

RESULTS

A total of 5803 patients met the criteria for this study. Wound complications occurred in 140 patients (2.4%) and were significantly associated with other adverse outcomes, including higher rates of unplanned reoperation (P < .0001) and prolonged length of stay (P < .0001). Regardless of fusion length, wound complication rates were higher with a posterior approach (short = 2.7%; long = 3.7%) than an anterior one (short = 2.2%; long = 2.7). According to the multivariate analysis, posterior fusion (odds ratio [OR] = 1.8; P = .010), obese class II (OR = 1.7; P = .046), obese class III (OR = 2.8; P < .0001), preoperative blood transfusion (OR = 6.1; P = .021), American Society of Anesthesiologists class ≥3 (OR = 1.7; P = .009), and operative time >4 hours (OR = 1.8; P = .006) were statistically significant risk factors for wound complications.

CONCLUSION

The 30-day incidence of wound complication in adult spinal deformity surgery is 2.4%. The risk factors for wound complication are multifactorial. This data should provide a step toward developing quality improvement measures aimed at reducing complications in high-risk adults.

Postoperative Radiculopathy Caused by a Retained Fractured Pedicle Cannulation Probe and Its Mechanism of Extraction

BACKGROUND

Spine surgery relies heavily on technology and surgical instrumentation. Improperly used instrumentation can be detrimental to the patient. Despite multiple checkpoints to ensure that foreign bodies are not retained in surgery, numerous case reports have described retained foreign bodies; however, none of these cases involve retained instrumentation after open spine surgery. Of the retained objects, 4 were sponges and one was a Jamshidi needle fragment. Although smaller objects are more commonly the culprits, surgical instruments can break off, remain stuck, and cause clinical sequelae.

CASE DESCRIPTION

This case presents a retained fractured pedicle finder as the cause of right L5 radiculopathy. To our knowledge, this report is the first to describe an instrumentation-associated postoperative radiculopathy. Because of the strength with which the object was impacted, its extraction proved difficult.

CONCLUSIONS

The technique of removal using a mallet and osteotome in 4 directions to loosen its hold in the vertebral body. Attempts and eventual successful removal are described.

Quantitative Computed Tomography Ventriculography for Assessment and Monitoring of Hydrocephalus: A Pilot Study and Description of Method in Subarachnoid Hemorrhage

BACKGROUND

There is no facile quantitative method for monitoring hydrocephalus (HCP). We propose quantitative computed tomography (CT) ventriculography (qCTV) as a novel computer vision tool for empirically assessing HCP in patients with subarachnoid hemorrhage (SAH).

METHODS

Twenty patients with SAH who were evaluated for ventriculoperitoneal shunt (VPS) placement were selected for inclusion. Ten patients with normal head computed tomography (CTH) findings were analyzed as negative controls. CTH scans were segmented both manually and automatically (by qCTV) to generate measures of ventricular volume.

RESULTS

The median manually calculated ventricular volume was 36.1 cm³ (interquartile range [IQR], 30-115 cm³), which was similar to the median qCTV measured volume of 37.5 cm³ (IQR, 32-118 cm³) (P = 0.796). Patients undergoing VPS placement demonstrated an increase in median ventricular volume on qCTV from 21 cm³ to 40 cm³ on day T-2 and to 51 cm³ by day 0, a change of 144%. This is in contrast to patients who did not require shunting, in whom median ventricular volume decreased from 16 cm³ to 14 cm³ on day T-2 and to 13 cm³ by day 0, with an average overall volume decrease 19% (P = 0.001). The average change in ventricular volume predicted which patients would require VPS placement, successfully identifying 7 of 10 patients (P = 0.004). Using an optimized cutoff of a change in ventricular volume of 2.5 cm³ identified all patients who went on to require VPS placement (10 of 10; P = 0.011).

CONCLUSIONS

qCTV is a reliable means of quantifying ventricular volume and hydrocephalus. This technique offers a new tool for monitoring neurosurgical patients for hydrocephalus, and may be beneficial for use in future research studies, as well as in the routine care of patients with hydrocephalus.

Thirty-Day Morbidity Associated with Pelvic Fixation in Adult Patients Undergoing Fusion for Spinal Deformity: A Propensity-Matched Analysis

STUDY DESIGN

Retrospective study of prospectively collected data.

OBJECTIVE

To determine if patients undergoing spinal deformity surgery with pelvic fixation are at an increased risk of morbidity.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program is a large multicenter clinical registry that prospectively collects preoperative risk factors, intraoperative variables, and 30-day postoperative morbidity and mortality outcomes from ~400 hospitals nationwide. Current Procedural Terminology codes were used to query the database between 2010 and 2014 for adults who underwent fusion for spinal deformity. Patients were separated into groups of those with and without pelvic fixation. Univariate analysis and multivariate logistic regression were used to analyze the effect of pelvic fixation on the incidence of postoperative morbidity and other surgical outcomes.

RESULTS

Multivariate analysis showed that pelvic fixation was a significant predictor of overall morbidity (odds ratio [OR] = 2.3, 95% confidence interval [CI]: 1.7 to 3.1, p = 0.0002), intra- or postoperative blood transfusion (OR = 2.3, 95% CI: 1.7 to 3.1 p < 0.0001), extended operative time (OR = 4.7, 95% CI: 3.1 to 7.0 p < 0.0001), and length of stay > 5 days (OR = 2.1, 95% CI 1.5 to 2.8, p < 0.0001) in patients undergoing fusion for spinal deformity. However, fusion to the pelvis did not lead to additional risk for other complications, including wound complications (p = 0.3191).

CONCLUSION

Adult patients undergoing spinal deformity surgery with pelvic fixation were not susceptible to increased morbidity beyond increased blood loss, greater operative time, and extended length of stay.

Outcome Instruments in Spinal Trauma Surgery: A Bibliometric Analysis

Study Design Literature review. Objective To identify outcomes instruments used in spinal trauma surgery over the past decade, their frequency of use, and usage trends. Methods Five top orthopedic journals were reviewed from 2004 to 2013 for clinical studies of surgical intervention in spinal trauma that reported patient-reported outcome instruments use or neurologic function scale use. Publication year, level of evidence (LOE), and outcome instruments were collected for each article and analyzed. Results A total of 58 studies were identified. Among them, 26 named outcome instruments and 7 improvised questionnaires were utilized. The visual analog scale (VAS) for pain was used most frequently (43.1%), followed by the Short Form 36 (34.5%), Frankel grade scale (25.9%), Oswestry Disability Index (20.7%) and American Spinal Injury Association Impairment Scale (15.5%). LOE 4 was most common (37.9%), and eight LOE 1 studies were identified (10.3%). Conclusions The VAS pain scale is the most common outcome instrument used in spinal trauma. The scope of this outcome instrument is limited, and it may not be sufficient for discriminating between more and less effective treatments. A wide variety of functional measures are used, reflecting the need for a disease-specific instrument that accurately measures functional limitation in spinal trauma.

A Comparative Analysis Among the SRS M&M, NIS, and KID Databases for the Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVES

A growing number of publications have utilized the Scoliosis Research Society (SRS) Morbidity and Mortality (M&M) database, but none have compared it to other large databases. The objective of this study was to compare SRS complications with those in administrative databases.

SUMMARY OF BACKGROUND DATA

The Nationwide Inpatient Sample (NIS) and Kid's Inpatient Database (KID) captured a greater number of overall complications while the SRS M&M data provided a greater incidence of spine-related complications following adolescent idiopathic scoliosis (AIS) surgery. Chi-square was used to obtain statistical significance, with p < .05 considered significant.

METHODS

The SRS 2004-2007 (9,904 patients), NIS 2004-2007 (20,441 patients) and KID 2003-2006 (10,184 patients) databases were analyzed for AIS patients who underwent fusion. Comparable variables were queried in all three databases, including patient demographics, surgical variables, and complications.

RESULTS

Patients undergoing AIS in the SRS database were slightly older (SRS 14.4 years vs. NIS 13.8 years, p < .0001; KID 13.9 years, p < .0001) and less likely to be male (SRS 18.5% vs. NIS 26.3%, p < .0001; KID 24.8%, p < .0001). Revision surgery (SRS 3.3% vs. NIS 2.4%, p < .0001; KID 0.9%, p < .0001) and osteotomy (SRS 8% vs. NIS 2.3%, p < .0001; KID 2.4%, p < .0001) were more commonly reported in the SRS database. The SRS database reported fewer overall complications (SRS 3.9% vs. NIS 7.3%, p < .0001; KID 6.6%, p < .0001). However, when respiratory complications (SRS 0.5% vs. NIS 3.7%, p < .0001; KID 4.4%, p < .0001) were excluded, medical complication rates were similar across databases. In contrast, SRS reported higher spine-specific complication rates. Mortality rates were similar between SRS versus NIS (p = .280) and SRS versus KID (p = .08) databases.

CONCLUSIONS

There are similarities and differences between the three databases. These discrepancies are likely due to the varying data-gathering methods each organization uses to collect their morbidity data.

LEVEL OF EVIDENCE

Level IV.

Minimally invasive cervical spine surgery

Degenerative disorders of the cervical spine requiring surgical intervention have become increasingly more common over the past decade. Traditionally, open surgical approaches have been the mainstay of surgical treatment. More commonly, minimally invasive techniques are being developed with the intent to decrease surgical morbidity and iatrogenic spinal instability. This study will review four minimally invasive cervical techniques that have been increasingly utilized in the treatment of degenerative cervical spine disease. A series of PubMed-National Library of Medicine searches were performed. Only articles in English journals or with published with English language translations were included. Level of evidence of the selected articles was assessed. The significant incidence of postoperative dysphagia following ACDF has led to the development and increased use of zero-profile, stand-alone anterior cervical cages. The currently available literature examining the safety and effectiveness of zero-profile interbody devices supports the use of these devices in patients undergoing single-level ACDF. A multitude of studies demonstrating the significant incidence and impact of axial neck pain following open posterior spine surgery have led to a wave of research and development of techniques aimed at minimizing posterior cervical paraspinal disruption while achieving appropriate neurological decompression and/or spinal fixation. The currently available literature supports the use of minimally invasive posterior cervical laminoforaminotomy for the treatment of single-level radiculopathy. The literature suggests that fluoroscopically-assisted percutaneous cervical lateral mass screw fixation appears to be a technically feasible, safe and minimally invasive technique. Based on the currently available literature it appears that the DTRAX® expandable cage system is an effective minimally invasive posterior cervical technique for the treatment of single-level cervical radiculopathy. Minimally invasive posterior cervical techniques continue to expand with the improvement of surgical instrumentation, microsurgical techniques and improved understanding of spinal biomechanics. While several MIS approaches already exist, there is a need for advanced and improved techniques for use in posterior cervical surgery.

The Burden of Clostridium difficile after Cervical Spine Surgery

Study Design Retrospective database analysis. Objective The purpose of this study is to investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after cervical spine surgery. Methods A total of 1,602,130 cervical spine surgeries from the Nationwide Inpatient Sample database from 2002 to 2011 were included. Patients were included for study based on International Classification of Diseases Ninth Revision, Clinical Modification procedural codes for cervical spine surgery for degenerative spine diagnoses. Baseline patient characteristics were determined. Multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. Results Incidence of C. difficile infection in postoperative cervical spine surgery hospitalizations is 0.08%, significantly increased since 2002 (p < 0.0001). The odds of postoperative C. difficile infection were significantly increased in patients with comorbidities such as congestive heart failure, renal failure, and perivascular disease. Circumferential cervical fusion (odds ratio [OR] = 2.93, p < 0.0001) increased the likelihood of developing C. difficile infection after degenerative cervical spine surgery. C. difficile infection after cervical spine surgery results in extended length of stay (p < 0.0001) and increased hospital costs (p < 0.0001). Mortality rate in patients who develop C. difficile after cervical spine surgery is nearly 8% versus 0.19% otherwise (p < 0.0001). Moreover, multivariate analysis revealed C. difficile to be a significant predictor of inpatient mortality (OR = 3.99, p < 0.0001). Conclusions C. difficile increases the risk of in-hospital mortality and costs approximately $6,830,695 per year to manage in patients undergoing elective cervical spine surgery. Patients with comorbidities such as renal failure or congestive heart failure have increased probability of developing infection after surgery. Accepted antibiotic guidelines in this population must be followed to decrease the risk of developing postoperative C. difficile colitis.

Annular puncture with tumor necrosis factor-alpha injection enhances painful behavior with disc degeneration in vivo

BACKGROUND CONTEXT

Painfulintervertebral disc degeneration is extremely common and costly. Effective treatments are lacking because the nature of discogenic pain is complex with limited capacity to distinguish painful conditions from age-related changes in the spine. Hypothesized sources of discogenic pain include chronic inflammation, neurovascular ingrowth, and structural disruption.

PURPOSE

This study aimed to investigate inflammation, pro-neurovascular growth factors, and structural disruption as sources of painful disc degeneration

STUDY DESIGN/SETTING

This study used an in vivo study to address these hypothesized mechanisms with anterior intradiscal injections of tumor necrosis factor-alpha (TNFα), pro-neurovascular growth factors: nerve growth factor and vascular endothelial growth factor (NGF and VEGF), and saline with additional sham surgery and naïve controls. Depth of annular puncture was also evaluated for its effects on structural and painful degeneration.

METHODS

Rat lumbar discs were punctured (shallow or deeper puncture) and intradiscally injected with saline, TNFα, or NGF and VEGF. Structural disc degeneration was assessed using X-ray, magnetic resonance imaging (MRI), and histology. The rat painful condition was evaluated using Von Frey hyperalgesia measurements, and substance P immunostaining in dorsal root ganglion (DRG) was performed to determine the source of pain.

RESULTS

Saline injection increased painful responses with degenerative changes in disc height, MRI intensity, and morphologies of disc structure and cell. TNFα and NGF/VEGF accelerated painful behavior, and TNFα-injected animals had increased substance P in DRGs. Deeper punctures led to more severe disc degeneration. Multiple regression analysis showed that the painful behavior was correlated with disc height loss.

CONCLUSIONS

We concluded that rate and severity of structural disc degeneration was associated with the amount of annular disruption and puncture depth. The painful behavior was associated with disc height loss and discal inflammatory state, whereas pro-inflammatory cytokines might play a more important role in the level of pain, which might have resulted from enhanced DRG sensitization. These in vivo painful disc degeneration models with different severities of structural changes may be useful for investigating discogenic pain mechanisms and for screening therapies, although interpretations must note the differences between all surgically induced animal models and the human condition.

The 100 Most Influential Articles in Cervical Spine Surgery

Study Design Literature review. Objective To identify and analyze the top 100 cited articles in cervical spine surgery. Methods The Thomson Reuters Web of Knowledge was searched for citations of all articles relevant to cervical spine surgery. The number of citations, authorship, year of publication, journal of publication, country of publication, and institution were recorded for each article. Results The most cited article was the classic from 1991 by Vernon and Mior that described the Neck Disability Index. The second most cited was Smith's 1958 article describing the anterior cervical diskectomy and fusion procedure. The third most cited article was Hilibrand's 1999 publication evaluating the incidence, prevalence, and radiographic progression of symptomatic adjacent segment disease following anterior cervical arthrodesis. The majority of the articles originated in the United States (65), and most were published in Spine (39). Most articles were published in the 1990s (34), and the three most common topics were cervical fusion (17), surgical complications (9), and biomechanics (9), respectively. Author Abumi had four articles in the top 100 list, and authors Goffin, Panjabi, and Hadley had three each. The Department of Orthopaedic Surgery at Hokkaido University in Sapporo, Japan, had five articles in the top 100 list. Conclusion This report identifies the top 100 articles in cervical spine surgery and acknowledges those individuals who have contributed the most to the advancement of the study of the cervical spine and the body of knowledge used to guide evidence-based clinical decision making in cervical spine surgery today.

Posterior-Only Circumferential Decompression and Reconstruction in the Surgical Management of Lumbar Vertebral Osteomyelitis

Study Design Case report. Objective The purpose of this report is to discuss the surgical management of lumbar vertebral osteomyelitis with a spinal epidural abscess (SEA) and present a single-stage, posterior-only circumferential decompression and reconstruction with instrumentation using an expandable titanium cage and without segmental nerve root sacrifice as an option in the treatment of this disease process. Methods We report a 42-year-old man who presented with 3 days of low back pain and chills who rapidly decompensated with severe sepsis following admission. Magnetic resonance imaging of his lumbosacral spine revealed intramuscular abscesses of the left paraspinal musculature and iliopsoas with SEA and L4 vertebral body involvement. The patient failed maximal medical treatment, which necessitated surgical treatment as a last resort for infectious source control. He underwent a previously undescribed procedure in the setting of SEA: a single-stage, posterior-only approach for circumferential decompression and reconstruction of the L4 vertebral body with posterior segmental instrumented fixation. Results After the surgery, the patient's condition gradually improved; however, he suffered a wound dehiscence necessitating a surgical exploration and deep wound debridement. Six months after the surgery, the patient underwent a revision surgery for adjacent-level pseudarthrosis. At 1-year follow-up, the patient was pain-free and off narcotic pain medication and had returned to full activity. Conclusion This patient is the first reported case of lumbar osteomyelitis with SEA treated surgically with a single-stage, posterior-only circumferential decompression and reconstruction with posterior instrumentation. Although this approach is more technically challenging, it presents another viable option for the treatment of lumbar vertebral osteomyelitis that may reduce the morbidity associated with an anterior approach.

Reliability Of A Surgeon-Reported Morbidity And Mortality Database: A Comparison Of Short-Term Morbidity Between The Scoliosis Research Society And National Surgical Quality Improvement Program Databases

BACKGROUND

There exists a lack of comparison between large national healthcare databases reporting surgical morbidity and mortality. Prior authors have expressed concern that the Scoliosis Research Society (SRS) membership may have underreported complications in spinal surgery. Thus, the purpose of the present study was to compare the incidence of morbidity between the SRS and National Surgical Quality Improvement Program (NSQIP) databases.

METHODS

We reviewed patients enrolled between 2012 and 2013, with a total of 96,875 patients identified in the SRS dataset and 15,909 in the combined adult and pediatric NSQIP dataset. Patients were matched based on diagnostic category,and a univariate analysis was used to compare reported complication rates in the categories of perioperative infection, neurologic injury, and mortality. The SRS database only requires detailed demographic data reporting on patients that have had a complication event. We compared the demographics and comorbidities of this subgroup, and used this as a surrogate to assess the potential magnitude of confounders.

RESULTS

Small differences existed between the SRS and NSQIP databases in terms of mortality (0.1% v. 0.2%), infection (1.2% v. 2%), and neurologic injury (0.8% v. 0.1%) (p<0.001 for each comparison). Infection rates were consistently lower across multiple diagnostic sub-categories in the SRS database, whereas neurologic injury rates were consistently lower in the NSQIP database. These differences reached statistical significance across several diagnostic subcategories, but the clinical magnitude of the differences was small. Amongst the patients with a complication, modest differences in comorbidities existed between the two cohorts.

CONCLUSION

Overall, the incidence of short-term morbidity and mortality was similar between the two databases. There were modest differences in comorbidities, which may explain the small differences observed in morbidity. Concerns regarding possible under-reporting of morbidity and mortality data by the SRS membership seem largely unfounded. This study may be useful for future investigators using the NSQIP and SRS datasets.

Perioperative outcomes in minimally invasive lumbar spine surgery: A systematic review

AIM: To compare minimally invasive (MIS) and open techniques for MIS lumbar laminectomy, direct lateral and transforaminal lumbar interbody fusion (TLIF) surgeries with respect to length of surgery, estimated blood loss (EBL), neurologic complications, perioperative transfusion, postoperative pain, postoperative narcotic use, and length of stay (LOS).

METHODS: A systematic review of previously published studies accessible through PubMed was performed. Only articles in English journals or published with English language translations were included. Level of evidence of the selected articles was assessed. Statistical data was calculated with analysis of variance with P < 0.05 considered statistically significant.

RESULTS: A total of 11 pertinent laminectomy studies, 20 direct lateral studies, and 27 TLIF studies were found. For laminectomy, MIS techniques resulted in a significantly longer length of surgery (177.5 min vs 129.0 min, P = 0.04), shorter LOS (4.3 d vs 5.3 d, P = 0.01) and less perioperative pain (visual analog scale: 16 ± 17 vs 34 ± 31, P = 0.04). There is evidence of decreased narcotic use for MIS patients (postoperative intravenous morphine use: 9.3 mg vs 42.8 mg), however this difference is of unknown significance. Direct lateral approaches have insufficient comparative data to establish relative perioperative outcomes. MIS TLIF had superior EBL (352 mL vs 580 mL, P < 0.0001) and LOS (7.7 d vs 10.4 d, P < 0.0001) and limited data to suggest lower perioperative pain.

CONCLUSION: Based on perioperative outcomes data, MIS approach is superior to open approach for TLIF. For laminectomy, MIS and open approaches can be chosen based on surgeon preference. For lateral approaches, there is insufficient evidence to find non-inferior perioperative outcomes at this time.

Patient Reported Outcomes in Adult Spinal Deformity Surgery: A Bibliometric Analysis

STUDY DESIGN

Bibliometric analysis.

OBJECTIVES

To identify patient-reported outcomes (PROs) used in adult spinal deformity (ASD) research over the past decade, their frequency, and usage trends.

SUMMARY OF BACKGROUND DATA

The emphasis on PROs is increasing along with the demand for evidence-based medicine. However, there is currently no standardization or consensus on which PROs ought to be used in ASD.

METHODS

Five top orthopedics journals were reviewed from 2004 to 2013 for clinical studies of surgical intervention in ASD that report PROs. Publication year, level of evidence (LOE), and PROs were collected for each article. Errors and inconsistencies of PRO score reporting were analyzed for the 3 most commonly used PROs.

RESULTS

A total of 84 PRO studies were published in ASD literature over the period studied. The number of PRO studies published increased from 1 in 2004 to 16 in 2013. We identified 24 unique PROs. The Oswestry Disability Index (ODI) was the most frequently used single instrument (47.8%), followed by the Scoliosis Research Society (SRS)-22 (35.6%) and SRS-24 (21.1%), and Short Form-36 (SF-36) and visual analog scale (VAS) were tied (13.3%). The combined use of SRS instruments exceeded ODI use. LOE 4 was most common (42.9%), and no LOE 1 studies were identified. Incomplete preoperative and postoperative PRO scores was the most common reporting inconsistency, occurring in 16% of articles using ODI, 58% of articles using SRS-24, and 22% of articles using SRS-22.

CONCLUSIONS

The frequency of studies using PROs in ASD research has increased over the past decade, yet quality studies and standardization are lacking. In general, the ODI and SRS instruments are emerging as standards in ASD surgery; however, frequent use of many uncommon PROs presents a challenge for interstudy comparisons. Additionally, of the top 5 instruments used, only SF-36 is routinely used for cost-effectiveness studies, making procedure cost-outcome decisions difficult.

To operate or not?: A literature review of surgical outcomes in 95 patients with Parkinson's disease undergoing spine surgery

INTRODUCTION

Degenerative spondylosis and kyphoscoliosis are increasingly recognized entities in patients with Parkinson's disease. Surgical treatment with spinal fusion can be complicated due to poor bone quality and muscular dysfunction in this patient population. The goal of this paper is to investigate surgical outcomes in Parkinson's patients undergoing spine surgery.

METHODS

We performed a literature review using the PubMed and Google Scholar search engines investigating "Parkinson's disease and spinal fusion surgery" from the period of 2000 to 2013. The inclusion criteria included only English articles with Parkinson's patients that underwent spinal surgery. We identified and reviewed all six articles that included ninety-five patients with Parkinson's disease who underwent spinal surgery.

RESULTS

A total of 95 patients with Parkinson's disease who underwent spinal fusion surgery were reviewed with average patient age of 69 and a 3:4 male to female ratio. With an average follow up of 40 months, 46 out of 73 patients (63%) were judged to have satisfactory outcomes with poor outcomes noted in the remaining 37%. These included but were not limited to pseudoarthrosis, hardware failure/pullout, development of adjacent level disease, persistent kyphosis or sagittal imbalance, and no improvement or worsening in their postoperative visual analog pain scale. There was a 45% (29/65) revision rate and a 59% (30/51) complication rate following the index procedure.

CONCLUSION

It remains unclear whether Parkinson's patients benefit from spinal fusion surgery. Further prospective research is warranted to investigate surgical outcomes in this subset of patients.

Assessment of functional and behavioral changes sensitive to painful disc degeneration

The development of an in vivo rodent discogenic pain model can provide insight into mechanisms for painful disc degeneration. Painful disc degeneration in rodents can be inferred by examining responses to external stimuli, observing pain-related behaviors, and measuring functional performance. This study compared the sensitivity of multiple pain and functional assessment methods to disc disruption for identifying the parameters sensitive to painful disc degeneration in rats. Disc degeneration was induced in rats by annular injury with saline injection. The severity of disc degeneration, pain sensitivity, and functional performance were compared to sham and naïve control rats. Saline injection induced disc degeneration with decreased disc height and MRI signal intensity as well as more fibrous nucleus pulposus, disorganized annular lamellae and decreased proteoglycan. Rats also demonstrated increased painful behaviors including decreased hindpaw mechanical and thermal sensitivities, increased grooming, and altered gait patterns with hindpaw mechanical hyperalgesia and duration of grooming tests being most sensitive. This is the first study to compare sensitivities of different pain assessment methods in an in vivo rat model of disc degeneration. Hindpaw mechanical sensitivity and duration of grooming were the most sensitive parameters to surgically induced degenerative changes and overall results were suggestive of disc degeneration associated pain.

The Internet as a communication tool for orthopedic spine fellowships in the United States

BACKGROUND CONTEXT

Orthopedic residents seeking additional training in spine surgery commonly use the Internet to manage their fellowship applications. Although studies have assessed the accessibility and content of Web sites in other medical specialties, none have looked at orthopedic spine fellowship Web sites (SFWs).

PURPOSE

The purpose of this study was to evaluate the accessibility of information from commonly used databases and assess the content of SFWs.

STUDY DESIGN

This was a Web site accessibility and content evaluation study.

METHODS

A comprehensive list of available orthopedic spine fellowship programs was compiled by accessing program lists from the SF Match, North American Spine Society, Fellowship and Residency Electronic Interactive Database (FREIDA), and Orthopaedicsone.com (Ortho1). These databases were assessed for accessibility of information including viable links to SFWs and responsive program contacts. A Google search was used to identify SFWs not readily available on these national databases. SFWs were evaluated based on online education and recruitment content.

RESULTS

Evaluators found 45 SFWs of 63 active programs (71%). Available SFWs were often not readily accessible from national program lists, and no program afforded a direct link to their SFW from SF Match. Approximately half of all programs responded via e-mail. Although many programs described surgical experience (91%) and research requirements (87%) during the fellowship, less than half mentioned didactic instruction (46%), journal clubs (41%), and national meetings or courses attended (28%). Evaluators found an average 45% of fellow recruitment content. Comparison of SFWs by program characteristics revealed three significant differences. Programs with greater than one fellowship position had greater online education content than programs with a single fellow (p=.022). Spine fellowships affiliated with an orthopedic residency program maintained greater education (p=.006) and recruitment (p=.046) content on their SFWs.

CONCLUSIONS

Most orthopedic spine surgery programs underuse the Internet for fellow education and recruitment. The inaccessibility of information and paucity of content on SFWs allow for future opportunity to optimize these resources.

Mesenchymal stem cell technology in the treatment of degenerative disc disease

AIM

Low back pain is the leading cause of disability and a major health problem around the world. As of today, symptomatic relief is the best option offered to patients, with mixed results. This study will review the use of mesenchymal stem cell (MSC) technology in the conservative and surgical treatments of degenerative disc disease (DDD).

METHODS

A series of PubMed-National Library of Medicine searches were performed. Only articles in English journals or with published with English language translations were included. Level of evidence of the selected articles was assessed.

RESULTS

There are multiple in-vitro and animal studies describing successful intervertebral disc (IVD) repair/regeneration with the use of live MSC therapy. Only 3 human studies (22 patients) with inconsistent results have been performed using bone marrow MSCs injected into diseased IVDs in patients with DDD. There exist multiple in-vitro and animal studies describing successful bony fusion with the use of MSC-containing bone graft substitutes. Only 3 retrospective human studies (115 patients) using CBM in spinal fusion have been performed with successful fusion rates ranging from 90.2%-92.3%. However, these studies lacked power and had significant conflicts of interest. There are multiple challenges with the use of MSC technology in humans.

CONCLUSION

MSCs may be a promising therapy in the treatment of DDD. However, their lack of success in human models leaves room for further research and focus in this field. Currently, there is no clinical evidence to support the use of this technology in the conservative or surgical management of patients with DDD.

Minimally invasive procedures on the lumbar spine

Degenerative disease of the lumbar spine is a common and increasingly prevalent condition that is often implicated as the primary reason for chronic low back pain and the leading cause of disability in the western world. Surgical management of lumbar degenerative disease has historically been approached by way of open surgical procedures aimed at decompressing and/or stabilizing the lumbar spine. Advances in technology and surgical instrumentation have led to minimally invasive surgical techniques being developed and increasingly used in the treatment of lumbar degenerative disease. Compared to the traditional open spine surgery, minimally invasive techniques require smaller incisions and decrease approach-related morbidity by avoiding muscle crush injury by self-retaining retractors, preventing the disruption of tendon attachment sites of important muscles at the spinous processes, using known anatomic neurovascular and muscle planes, and minimizing collateral soft-tissue injury by limiting the width of the surgical corridor. The theoretical benefits of minimally invasive surgery over traditional open surgery include reduced blood loss, decreased postoperative pain and narcotics use, shorter hospital length of stay, faster recover and quicker return to work and normal activity. This paper describes the different minimally invasive techniques that are currently available for the treatment of degenerative disease of the lumbar spine.

Cellular bone matrices: viable stem cell-containing bone graft substitutes

BACKGROUND CONTEXT

Advances in the field of stem cell technology have stimulated the development and increased use of allogenic bone grafts containing live mesenchymal stem cells (MSCs), also known as cellular bone matrices (CBMs). It is estimated that CBMs comprise greater than 17% of all bone grafts and bone graft substitutes used.

PURPOSE

To critically evaluate CBMs, specifically their technical specifications, existing published data supporting their use, US Food and Drug Administration (FDA) regulation, cost, potential pitfalls, and other aspects pertaining to their use.

STUDY DESIGN

Areview of literature.

METHODS

A series of Ovid, Medline, and Pubmed-National Library of Medicine/National Institutes of Health (www.ncbi.nlm.nih.gov) searches were performed. Only articles in English journals or published with English language translations were included. Level of evidence of the selected articles was assessed. Specific technical information on each CBM was obtained by direct communication from the companies marketing the individual products.

RESULTS

Five different CBMs are currently available for use in spinal fusion surgery. There is a wide variation between the products with regard to the average donor age at harvest, total cellular concentration, percentage of MSCs, shelf life, and cell viability after defrosting. Three retrospective studies evaluating CBMs and fusion have shown fusion rates ranging from 90.2% to 92.3%, and multiple industry-sponsored trials are underway. No independent studies evaluating spinal fusion rates with the use of CBMs exist. All the commercially available CBMs claim to meet the FDA criteria under Section 361, 21 CFR Part 1271, and are not undergoing FDA premarket review. The CBMs claim to provide viable MSCs and are offered at a premium cost. Numerous challenges exist in regard to MSCs' survival, function, osteoblastic potential, and cytokine production once implanted into the intended host.

CONCLUSIONS

Cellular bone matrices may be a promising bone augmentation technology in spinal fusion surgery. Although CBMs appear to be safe for use as bone graft substitutes, their efficacy in spinal fusion surgery remains highly inconclusive. Large, nonindustry sponsored studies evaluating the efficacy of CBMs are required. Without results from such studies, surgeons must be made aware of the potential pitfalls of CBMs in spinal fusion surgery. With the currently available data, there is insufficient evidence to support the use of CBMs as bone graft substitutes in spinal fusion surgery.

A review of the current published spinal literature regarding bone morphogenetic protein-2: an insight into potential bias

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a potent biologic agent that carries both osteoinductive and osteoconductive properties. Its potential as an autologous bone graft substitute in spine surgery led to its approval by the United States Food and Drug Administration (FDA) in 2002 following a series of industry-sponsored trials. Although approved for a single level anterior lumbar interbody fusion from L4-S1 with a proprietary cage, the off-label use of rhBMP-2 rapidly escalated. Soon thereafter, reports of serious and potentially life-threatening complications associated with rhBMP-2 began emerging, which sparked concerns with regards to potential bias in the original FDA trials. Ultimately, an independent review of all published and unpublished data on the safety and effectiveness of rhBMP-2 by the Yale University Open Data Access (YODA) Project determined that while rhBMP-2 is as effective as iliac crest bone graft (ICBG) in potentiating spinal fusion, there was significant bias and conflicts of interests that resulted in an underreporting of complications in the original industry-sponsored trials.

Increased incidence of pseudarthrosis after unilateral instrumented transforaminal lumbar interbody fusion in patients with lumbar spondylosis: Clinical article

OBJECT

Transforaminal lumbar interbody fusion (TLIF) with segmental pedicular instrumentation is a well established procedure used to treat lumbar spondylosis with or without spondylolisthesis. Available biomechanical and clinical studies that compared unilateral and bilateral constructs have produced conflicting data regarding patient outcomes and hardware complications.

METHODS

A prospective cohort study was undertaken by a group of neurosurgeons. They prospectively enrolled 80 patients into either bilateral or unilateral pedicle screw instrumentation groups (40 patients/group). Demographic data collected for each group included sex, age, body mass index, tobacco use, and Workers' Compensation/litigation status. Operative data included segments operated on, number of levels involved, estimated blood loss, length of hospital stay, and perioperative complications. Long-term outcomes (hardware malfunction, wound dehiscence, and pseudarthrosis) were recorded. For all patients, preoperative baseline and 6-month postoperative scores for Medical Outcomes 36-Item Short Form Health Survey (SF-36) outcomes were recorded.

RESULTS

Patient follow-up times ranged from 37 to 63 months (mean 52 months). No patients were lost to follow-up. The patients who underwent unilateral pedicle screw instrumentation (unilateral cohort) were slightly younger than those who underwent bilateral pedicle screw instrumentation (bilateral cohort) (mean age 42 vs. 47 years, respectively; p = 0.02). No other significant differences were detected between cohorts with regard to demographic data, mean number of lumbar levels operated on, or distribution of the levels operated on. Estimated blood loss was higher for patients in the bilateral cohort, but length of stay was similar for patients in both cohorts. The incidence of pseudarthrosis was significantly higher among patients in the unilateral cohort (7 patients [17.5%]) than among those in the bilateral cohort (1 patient [2.5%]) (p = 0.02). Wound dehiscence occurred for 1 patient in the unilateral cohort. Reoperation was offered to 8 patients in the unilateral cohort and 1 patient in the bilateral cohort (p = 0.03). The physical component scores of the Medical Outcomes SF-36 outcomes improved significantly for all patients (p < 0.001).

CONCLUSIONS

Transforaminal lumbar interbody fusion with either unilateral or bilateral segmental pedicular instrumentation is an effective treatment for lumbar spondylosis. Because patients with unilateral constructs were 7 times more likely to experience pseudarthrosis and require reoperation, TLIF with bilateral constructs might be the biomechanically superior technique.

Cervical-petrous internal carotid artery pseudoaneurysm presenting with otorrhagia treated with endovascular techniques

Cervical-petrous internal carotid artery (CP-ICA) pseudoaneurysms are rare and have different etiologies, presentations, and treatment options. A middle-aged patient with a history of chronic otitis media presented with acute otorrhagia and was found to have a left-sided CP-ICA pseudoaneurysm. The patient was a poor surgical candidate with difficult arterial access. The pseudoaneurysm was treated with stand-alone coiling via a left brachial approach with persistent contrast filling seen only in the aneurysm neck at the end of the procedure. The patient re-presented 12 days later with repeat hemorrhage and rapid enlargement of the neck remnant, and was treated with a covered stent via a transcervical common carotid artery cut-down. A covered stent may provide a more definitive treatment for CP-ICA pseudoaneurysms compared with standalone coiling.

The 100 Classic Papers in Spinal Deformity Surgery

STUDY DESIGN

Bibliometric review of the literature.

OBJECTIVE

To identify and analyze the top 100 cited articles in spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

The field of spinal deformity surgery is an ever-growing and complex field that owes its development to the work and visions of many dedicated individuals.

METHODS

The authors searched the Thomson Reuters Web of Knowledge for citations of all articles relevant to scoliosis and spinal deformity surgery. The number of citations, authorship, year, journal, and country and institution of publication were recorded for each article.

RESULTS

The most cited article was the 2001 work by Lenke et al. describing a new 2-dimensional classification system of adolescent idiopathic scoliosis used to determine the appropriate vertebral levels to be included in an arthrodesis. The second most cited was Harrington's 1962 article describing the first instrumented method for the treatment of scoliosis. The third most cited article was the 1983 study by King et al. recommending specific vertebral levels for inclusion into spinal arthrodesis. Most articles originated in the United States (62), and most were published in Spine (32). Most were published in the 1990s (28), and the 3 most common topics, in descending order, were adolescent idiopathic scoliosis (28), spinal instrumentation (18), and surgical complications (5). Author Suk had 5 articles in the top 100 list, whereas authors Kim, Liljenqvist, Lonstein, and Weinstein had 3 each. Washington University in St. Louis had 7 articles in the top 100 list.

CONCLUSIONS

This report's identification of the 100 classic articles in spinal deformity surgery allows insight into the development and trends of this challenging subspecialty of spine surgery. Furthermore, this article identifies individuals who have contributed the most to the advancement of spinal deformity surgery and the body of knowledge used to guide evidence-based clinical decision making in spinal deformity surgery today.

Cervical-petrous internal carotid artery pseudoaneurysm presenting with otorrhagia treated with endovascular techniques

Cervical-petrous internal carotid artery (CP-ICA) pseudoaneurysms are rare and have different etiologies, presentations, and treatment options. A middle-aged patient with a history of chronic otitis media presented with acute otorrhagia and was found to have a left-sided CP-ICA pseudoaneurysm. The patient was a poor surgical candidate with difficult arterial access. The pseudoaneurysm was treated with stand-alone coiling via a left brachial approach with persistent contrast filling seen only in the aneurysm neck at the end of the procedure. The patient re-presented 12 days later with repeat hemorrhage and rapid enlargement of the neck remnant, and was treated with a covered stent via a transcervical common carotid artery cut-down. A covered stent may provide a more definitive treatment for CP-ICA pseudoaneurysms compared with standalone coiling.

Pilomyxoid astrocytoma of the cerebellar vermis in an elderly patient

Background:

Pilomyxoid astrocytoma (PMA) has recently been accepted as an aggressive variant of pilocytic astrocytoma with distinct histopathological features. PMAs have been frequently described in the pediatric population with a predilection for the hypothalamic/chiasmatic region.

Case Description:

A 72-year-old African American male presented with 6 months of memory loss, difficulty expressing himself, and a progressively worsening gait. Magnetic resonance imaging of the brain demonstrated a heterogeneously enhancing cystic mass centered within the cerebellar vermis with mass effect on the fourth ventricle and ventriculomegaly. The patient underwent placement of a ventriculoperitoneal shunt followed by a surgical resection of the lesion, which after immunohistopathologic evaluation, was diagnosed as a World Health Organization grade II PMA. The patient refused further treatment of the lesion and expired 11 months after initial symptom presentation and 4 months after surgery.

Conclusion:

To our knowledge, this is the first report of PMA of the cerebellar vermis in a previously unreported age group. This case report describes the natural history of this type of tumor in a patient who refused adjuvant therapy following surgical resection.

Acute respiratory failure from Surgifoam expansion after anterior cervical surgery

A 65-year-old woman underwent an uneventful C3–4 anterior cervical discectomy and fusion for a large, symptomatic disc herniation. On postoperative Day 1 the patient suffered a sudden, acute respiratory compromise. Emergency fiberoptic intubation revealed significant anterior neck swelling with concern for physical obstruction of the airway. Computed tomography of the neck did not demonstrate an expanding hematoma. The patient was managed with surgical wound exploration and washout. Examination of the anterior neck after incision of the prior surgical site revealed a large volume of Surgifoam under high pressure, which was greater than the amount used during the initial surgery. Thorough washout of the surgical site did not reveal any swelling of the prevertebral soft tissues or hematoma, and the Hemovac drain did not appear to be occluded. The patient was extubated on the 2nd postoperative day and is symptom free 12 months after surgery. To the authors' knowledge, this report represents the first reported complication of acute respiratory failure from Surgifoam overexpansion after anterior cervical surgery.

Progressive visual loss following rupture of an intracranial dermoid cyst

A 51-year-old man with several months of headache and progressive visual decline was found to have bilateral optic disc pallor with significant impairment of visual acuity. Despite a thorough ophthalmologic evaluation, the cause of visual loss could not be elucidated. MRI of the brain revealed a lesion in the left anterior Sylvian fissure as well as disseminated foci of subarachnoid fat consistent with a diagnosis of a ruptured dermoid cyst. The decision for open surgical resection was chosen to minimize the risk of cyst re-rupture and further visual or neurologic decline. The diagnosis of dermoid cyst was confirmed at the time of surgery. Vasospasm-induced ischemia of the optic nerves, optic chiasm or bilateral optic tracts secondary to the inflammatory reaction following cyst rupture is the most likely mechanism of visual loss in this patient. To the authors' knowledge, this report represents the first reported case of visual loss secondary to rupture of an intracranial dermoid cyst not related to mass effect of the tumor on the optic apparatus, visual pathways or visual cortex.