Amyloidoma: a review and case report.

Amyloidoma is a solitary mass of amyloid protein that arises in patients with or without evidence of systemic amyloidosis, and can be found in a variety of different organ systems. Herein, we describe three cases of localized biopsy-positive amyloidomas with no evidence of systemic involvement-primary amyloidoma. Our cases include a patient with a paraspinal soft tissue amyloidoma, a patient with multiple primary amyloidomas involving the thoracic cavity and flank, and a patient with insulin-injection induced amyloidoma of the left shoulder. We present these cases to provide further insights into the clinical presentation of this uncommon clinical entity. We review the pathophysiology of amyloidosis and discuss our cases in the context of previous reports of amyloidoma.

Why you should wear your seatbelt on an airplane: Burst fracture of the atlas (jefferson fracture) due to in-flight turbulence.

The Jefferson fracture is a burst-type fracture to the atlas first described in 1919, characterized by anterior and posterior fractures of the weak C1 ring caused by a sudden axial load to the vertex of the skull. Here we report a Jefferson fracture caused by head trauma due to mid-flight turbulence in an unrestrained 56-year-old male airline passenger. Imaging revealed a comminuted burst fracture of the atlas with an avulsion fracture of the transverse atlantal ligament. The patient was treated conservatively in a Miami-J collar with close clinical and radiographic follow-up. Lateral flexion-extension radiographs demonstrated fracture stability, and clinically the patient lacked pain or neurologic symptoms at 12 weeks from injury. To our knowledge this is the first report of a Jefferson fracture caused by axial compression attributable to in-flight turbulence. Traditionally associated with automobile crashes and diving headfirst into shallow pools, the axial load results in a compressive force to the atlas and subsequent lateral separation of the two halves of the C1 vertebral ring. The purpose of this case study is to alert providers, aircraft personnel, and passengers of the inherent risk of air travel and the importance of wearing a seatbelt at all times, describe the signs and symptoms of this often-overlooked fracture, and provide general treatment guidelines based on radiographic assessments of fracture stability.

The Safety Profile of Percutaneous Minimally Invasive Sacroiliac Joint Fusion.

STUDY DESIGN: Literature review. OBJECTIVES: Systematic review of the existing literature to determine the safety of minimally invasive (MI) sacroiliac (SI) joint fusion through the determination of the rate of procedural and device-related intraoperative and postoperative complications. METHODS: All original studies with reported complication rates were included for analysis. Complications were defined as procedural if secondary to the MI surgery and device related if caused by placement of the implant. Complication rates are reported using descriptive statistics. Random-effects meta-analysis was performed for preoperative and postoperative Visual Analog Score (VAS) pain ratings and Oswestry Disability Index (ODI) scores. RESULTS: Fourteen studies of 720 patients (499 females/221 males) with a mean follow-up of 22 months were included. Ninety-nine patients (13.75%) underwent bilateral SI joint arthrodesis resulting in a total of 819 SI joints fused. There were 91 reported procedural-related complications (11.11%) with the most common adverse event being surgical wound infection/drainage (n = 17). Twenty-five adverse events were attributed to be secondary to placement of the implant (3.05%) with nerve root impingement (n = 13) being the most common. The revision rate was 2.56%. MI SI joint fusion reduced VAS scores from 82.42 (95% confidence interval [CI] 79.34-85.51) to 29.03 (95% CI 25.05-33.01) and ODI scores from 57.44 (95% CI 54.73-60.14) to 29.42 (95% CI 20.62-38.21). CONCLUSIONS: MI SI joint fusion is a relatively safe procedure but is not without certain risks. Further work must be done to optimize the procedure's complication profile. Possible areas of improvement include preoperative patient optimization, operative technique, and use of intraoperative real-time imaging.

Dysphagia following lumbar spine surgery in the setting of undiagnosed DISH of the cervical spine: a case report.

Dysphagia is an often multifactorial pathology affecting many elderly patients. In addition to global neuromuscular change with normal aging, one component of its etiology may be direct compression of the pharynx or esophagus from overgrown bone from the anterior cervical spine. Diffuse idiopathic skeletal hyperostosis (DISH) is one condition that may contribute to this phenomenon. Of relatively high incidence (2.5% to 33.3%) in elderly populations, DISH has been described in the cervical spine though more frequently affects other spinal regions. The clinical case of an elderly man who developed significant dysphagia after undergoing lumbar spine surgery for spinal stenosis caused by DISH is presented. Awareness of the involvement in his cervical spine before surgery would likely have enabled a more prompt diagnosis of the etiology of dysphagia and allowed for peri-operative optimization of swallowing function to reduce morbidity. We recommend routine preoperative imaging of the cervical spine in all patients with a diagnosis of DISH to stratify risk for development of postoperative dysphagia.

Multidisciplinary Management of Spinal Metastasis and Vertebral Instability: A Systematic Review.

OBJECTIVE: The aim of this systematic literature review is to evaluate recent attempts in creating a standardized multidisciplinary approach combining tumor treatment with current vertebral stabilization techniques for palliative treatment of vertebral metastasis in patients who do not fall into the NOMS (neurologic, oncologic, mechanical, systemic) framework. METHODS: We performed a systematic literature search for studies using a tumor modality in conjunction with kyphoplasty or vertebroplasty. In addition, the bibliographies of selected articles were examined for additional studies not viewed in database searches, which led to the use of additional search terms. RESULTS: A total of 563 articles were found after our database search. Eighteen studies fulfilled our inclusion criteria. Articles were then divided into categories based on combinations of tumor modality. Multiple studies reported significant decreases in visual analog scale scores after combined procedures with very low rates of symptomatic complications. Studies that compared their combination with control treatment groups showed greater clinical efficacy. CONCLUSIONS: Although multidisciplinary management of spinal metastasis using a combination of tumor ablation techniques with vertebral stabilization has been recommended in the previous literature, this review shows that no combination of treatment carried demonstrably different results in pain score reduction, reduced analgesic intake, or improved quality of life. In addition, there is no consensus of standardized variables to evaluate efficacy of treatment, limiting the efficacy of treatment results for the analyzed studies. Although not explicitly included in the initial NOMS framework, our results support the consideration of concomitant percutaneous kyphoplasty or vertebroplasty in these patients on a case-by-case basis.

Evaluating Treatment Strategies for Spinal Lesions in Multiple Myeloma: A Review of the Literature.

BACKGROUND: Vertebral disease is a major cause of morbidity in 70% of patients diagnosed with multiple myeloma (MM). Associated osteolytic lesions and vertebral fractures are well documented in causing debilitating pain, functional restrictions, spinal deformity, and cord compression. Currently, treatment modalities for refractory MM spinal pain include systemic therapy, radiotherapy, cementoplasty (vertebroplasty/kyphoplasty), and radio frequency ablation. Our objectives were to report on the efficacy of existing treatments for MM patients with refractory spinal pain, to determine if a standardized treatment algorithm has been described, and to set the foundation upon which future prospective studies can be designed. METHODS: A systematic search of the PubMed database was performed for studies relevant to the treatment of vertebral disease in MM patients. A multitude of search terms in various combinations were used, including but not limited to: "vertebroplasty," "kyphoplasty," "radiation," "multiple myeloma," "radiotherapy," and "radiosurgery." RESULTS: Our preliminary search resulted in 219 articles, which subsequently resulted in 19 papers following abstract, title, full-text, and bibliography review. These papers were then grouped by treatment modality: radiotherapy, cementoplasty, or combination therapy. Significant pain and functional score improvement across all treatment modalities was found in the majority of the literature. While complications of treatment occurred, few were noted to be clinically significant. CONCLUSIONS: Treatment options-radiotherapy and/or cementoplasty-for vertebral lesions and pathologic fractures in MM patients demonstrate significant radiographic and clinical improvement. However, there is no consensus in the literature as to the optimal treatment modality as a result of a limited number of studies reporting head-to-head comparisons. One study did find significantly improved pain and functional scores with preserved vertebral height in favor of kyphoplasty over radiotherapy. When not contraindicated, we advocate for some form of cementoplasty. Further prospective studies are required before implementation of a standardized treatment protocol. LEVEL OF EVIDENCE: 5.

Spine Trauma From Personal Watercraft Usage.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To identify patient characteristics and associated injuries in those sustaining a spine fracture from personal watercraft (PWC) usage. SUMMARY OF BACKGROUND DATA: There are few studies regarding PWC use and injuries, and even more scarce are studies evaluating PWC usage and spine injuries. Identifying high-risk actions and individuals can help to effectively treat them, reduce mortality, and possibly avoid certain spine fractures. METHODS: Retrospective analysis of 142 patients admitted from the emergency department with PWC-related injuries at a single-level I trauma center from January 1, 2004 to May 1, 2017. Twenty-six (18.3%) sustained a spine fracture, totaling 71 fractures. Statistical analysis was used to investigate the patient characteristics, specific mechanisms of injury, injury severity score (ISS), and associated injuries. Patients expiring (12) had incomplete evaluations and were excluded from most reported results. RESULTS: Spine fractures were not associated with age, race, or sex, but were associated with a higher ISS, intensive care unit length, in-patient length of stay, cerebral injury, and abdominal/genitourinary (GU) injury. There were 8 cervical fractures, 22 thoracic fractures, 33 lumbar, and 8 sacral fractures. Axial load injuries were associated with vertebral body fractures and specifically burst fractures. Being a driver or passenger did not influence likelihood of a spine fracture, but did correlate with abdominal/GU injury. Five (19.2%) of patients with spine fractures required eight spine surgeries during admission. Mortality was associated with females, severe systemic injuries (ISS ≥ 15), direct collision mechanism of injury, and the spring season. CONCLUSION: PWC usage may result in spine fractures with a moderate percentage requiring orthopedic surgery. Additional studies should examine how hull or seat modifications can lessen the risk of axial loads leading to spine fractures. PWC patients with spine fractures should also be evaluated for abdominal/GU and cerebral injuries at presentation. LEVEL OF EVIDENCE: 4.

Lateral lumbar interbody fusion with unilateral pedicle screw fixation for the treatment of adjacent segment disease: a preliminary report.

BACKGROUND: To assess the clinical outcomes of 20 patients who underwent single level unilateral pedicle screw fixation following lateral lumbar interbody fusion (LLIF) for treatment of lumbar adjacent segment disease (ASD). METHODS: Demographic, comorbidity, clinical assessment, peri-operative, and complication data were assessed. Visual analog scale (VAS), Oswestry disability index (ODI), and short form-12 (SF-12) were used to assess clinical outcomes. Post-operative radiographs were assessed for subsidence, cage migration, and fusion. RESULTS: Average age of patients was 63.2±13.7 years (range, 41-86 years), with 8 males and 12 females. Recombinant human bone morphogenic protein-2 (rhBMP-2) was utilized in 18 LLIF cages (90%) and 12 posterolateral fusions (60%). Mean operation time was 214.1±47.2 minutes (range, 146-342 minutes), mean estimated blood loss of 187.5±90.1 cc (range, 50-400 cc). No patients received a blood transfusion. There were no intra-operative complications. Mean hospital length of stay was 4.4±1.7 days (range, 2-9 days). At final follow-up (mean: 13.0±12.7 months after surgery), there was significant improvement in post-op VAS (P=0.006) score compared to pre-op, but not ODI (P=0.181), SF-12 PC (P=0.480), and SF-12 MC (P=0.937). Patients with >6 months of post-operative imaging (14/20, 70%) demonstrated successful fusion in 13 out of 14 cases (93%). There was grade 0 subsidence of adjacent cranial vertebra in all cases (100%). There was grade 0 subsidence of the adjacent caudal vertebra in 13 cases (93%) and grade 1 subsidence in 1 case (7%). There was evidence of cage migration in 3 cases (21%). There were 4 patients (20%) who experienced transient neurological deficits that eventually resolved. Two patients required surgery for further ASD. CONCLUSIONS: In conclusion, this pilot study suggests that patients who undergo LLIF with unilateral pedicle screw fixation for treatment of ASD may have significantly reduced pain and favorable radiographic results. Further investigation in techniques for treatment of ASD is warranted.

Early clinical and radiological results of unilateral posterior pedicle instrumentation through a Wiltse approach with lateral lumbar interbody fusion.

BACKGROUND: To assess the clinical outcomes of 44 patients who underwent single-level lateral lumbar interbody fusion (LLIF) with unilateral pedicle screw instrumentation through a paramedian Wiltse approach. METHODS: Demographic, comorbidity, clinical assessment, peri-operative, and complication data were assessed. Visual analog scale (VAS), Oswestry disability index (ODI), and short form-12 (SF-12) were used to assess clinical outcomes. Post-operative plain radiographs were assessed for subsidence, cage migration, and fusion. RESULTS: Average age of patients at surgery was 60.8±10.6 years (range, 32-79 years), with 15 males and 29 females. Recombinant human bone morphogenic protein-2 (rhBMP-2) was used in 32 cases (73%) and 13 posterolateral fusions (30%). Average duration of surgery was 195.2±36.9 minutes (range: 111-295 minutes), with an estimated blood loss of 159.3±90.8 cc (range, 50-500 cc). There were no intra-operative complications. Average length of hospital stay was 4.2±2.5 days (range, 2-13 days). Four patients (9%) experienced neurological deficit, 2 of which resolved by 3-month follow-up and 2 of which improved but did not resolve by final follow-up at 11 and 16 months. There was significant improvement in VAS (P<0.001), ODI (P<0.001), and SF-12 physical component (P<0.001), but not for SF-12 mental component (P=0.053). Patients with minimum 6 months radiographic follow-up demonstrated successful fusion in 90% of cases (35/39), with 2 cases of grade 1 (5%) subsidence of the adjacent cranial vertebra, and no cases higher than grade 0 subsidence of the adjacent caudal vertebra. CONCLUSIONS: Unilateral pedicle screw instrumentation following LLIF was associated with significant improvement in clinical outcomes and favorable radiographic outcomes.

Robotic paravertebral schwannoma resection at extreme locations of the thoracic cavity.

Solitary paravertebral schwannomas in the thoracic spine and lacking an intraspinal component are uncommon. These benign nerve sheath tumors are typically treated using complete resection with an excellent outcome. Resection of these tumors is achieved by an anterior approach via open thoracotomy or minimally invasive thoracoscopy, by a posterior approach via laminectomy, or by a combination of both approaches. These tumors most commonly occur in the midthoracic region, for which surgical removal is usually straightforward. The authors of this report describe 2 cases of paravertebral schwannoma at extreme locations of the posterior mediastinum, one at the superior sulcus and the other at the inferior sulcus of the thoracic cavity, for which the usual surgical approaches for safe resection can be challenging. The tumors were completely resected with robot-assisted thoracoscopic surgery. This report suggests that single-stage anterior surgery for this type of tumor in extreme locations is safe and effective with this novel minimally invasive technique.

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.

Primary Osteosarcoma of the Bone with Rhabdoid Features: A Rare, Previously Undescribed Primary Malignant Tumor of Bone.

Primary osteosarcoma of the bone with rhabdoid features is a rare malignant tumor of bone, not previously described in the literature. Here we report a 69-year-old female who originally presented with a right femur pathologic fracture. Radiographs of the injury showed an aggressive-appearing lesion of the distal femur. Initial biopsy was done, which was not diagnostic; additional advanced imaging studies were performed, which failed to show any other site within the body with detectable disease process. Accordingly, the patient underwent radical resection of the distal femur and reconstruction with endoprosthesis. Histopathology obtained from the operative specimen showed osteosarcoma with rhabdoid features. Two months after surgery, the patient is symptom-free and doing well; she is currently pending adjuvant chemotherapy. Although rhabdoid features have been described in extraskeletal osteosarcoma, this appears to be the first mention of osteosarcoma of bone with rhabdoid features in the literature.

Patient-Reported Outcome Instruments in Pediatric Deformity Surgery: A Bibliometric Analysis.

STUDY DESIGN: Bibliometric analysis. OBJECTIVES: To identify patient-reported outcomes instruments (PROIs) used in pediatric deformity surgery research over the past decade and their frequency and usage trends. SUMMARY OF BACKGROUND DATA: The emphasis on PROIs is increasing along with the demand for evidence-based medicine and cost-effectiveness research. Therefore, investigators and PROI consensus writers should be aware of the PROIs used in pediatric deformity and usage trends. METHODS: Five top orthopedics journals were reviewed from 2004 to 2013 for clinical studies of surgical intervention in pediatric deformity that report PROIs. Publication year, level of evidence (LOE), and PROIs were reported for each article. Mean and range scores for the most frequently used PROIs were analyzed at 2-year follow-up. RESULTS: A total of 79 studies using PROIs were published in the pediatric deformity literature over the period studied. The researchers identified 21 named PROIs and 6 additional custom questionnaires. The Scoliosis Research Society (SRS)-22 was the most frequently used instrument (32.9%), followed by the SRS-24 (29.1%), Oswestry disability index (17.7%), visual analog scale (12.7%), SRS-30 (10.1%), and Short Form-36 (6.3%). Level of evidence III was most common (39.2%) and 1 LOE I study was identified. Mean preoperative and postoperative SRS instrument scores were 4.0 (95% confidence interval, 3.8-4.1) and 4.5 (95% confidence interval, 4.4-4.6), respectively, in SRS-22r equivalents. No studies met the criteria for mean and range calculation for the other top instruments. CONCLUSIONS: Scoliosis Research Society instruments are used in 74.7% of pediatric deformity studies reporting PROIs. Therefore, there is a consensus that SRS instruments should be used in pediatric deformity outcome studies; yet, consistent use of the most up-to-date version, the SRS-22r, is still needed. General health questionnaires are currently underused in pediatric deformity research. Version reporting and use of the latest versions of PROIs need to be improved in future studies.

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.

Clostridium difficile colitis in patients undergoing lumbar spine surgery.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: To investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after lumbar spine surgery. SUMMARY OF BACKGROUND DATA: C. difficile colitis is reportedly increasing in hospitalized patients and can have a negative impact on patient outcomes. No data exist on estimates of C. difficile infection rates and its consequences on patient outcomes and health care resources among patients undergoing lumbar spine surgery. METHODS: The Nationwide Inpatient Sample was examined from 2002 to 2011. Patients were included for study based on International Classification of Diseases, Ninth Revision, Clinical Modification, procedural codes for lumbar spine surgery for degenerative diagnoses. Baseline patient characteristics were determined and multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. RESULTS: The incidence of C. difficile infection in patients undergoing lumbar spine surgery is 0.11%. At baseline, patients infected with C. difficile were significantly older (65.4 yr vs. 58.9 yr, P<0.0001) and more likely to have diabetes with chronic complications, neurological complications, congestive heart failure, pulmonary disorders, coagulopathy, and renal failure. Lumbar fusion (P=0.0001) and lumbar fusion revision (P=0.0003) were associated with increased odds of postoperative infection. Small hospital size was associated with decreased odds (odds ratio [OR], 0.5; P<0.001), whereas urban hospitals were associated with increased odds (OR, 2.14; P<0.14) of acquiring infection. Uninsured (OR, 1.62; P<0.0001) and patients with Medicaid (OR, 1.33; P<0.0001) were associated with higher odds of acquiring postoperative infection. C. difficile increased hospital length of stay by 8 days (P<0.0001), hospital charges by 2-fold (P<0.0001), and inpatient mortality to 4% from 0.11% (P<0.0001). CONCLUSION: C. difficile infection after lumbar spine surgery carries a 36.4-fold increase in mortality and costs approximately $10,658,646 per year to manage. These data suggest that great care should be taken to avoid C. difficile colitis in patients undergoing lumbar spine surgery because it is associated with longer hospital stays, greater overall costs, and increased inpatient mortality. LEVEL OF EVIDENCE: 3.

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.

Multivariate analysis on risk factors for postoperative ileus after lateral lumbar interbody fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To assess for independent risk factors of postoperative ileus (POI) after lateral lumbar interbody fusion (LLIF). SUMMARY OF BACKGROUND DATA: POI is frequently observed in anterior lumbar interbody fusion due to significant bowel manipulation during the approach. LLIF is a minimally invasive approach to the anterior column with reduced bowel manipulation and surgical time. However, there is a paucity of literature on POI after LLIF. METHODS: A retrospective review was performed of records of patients who underwent LLIF from January 2006 to December 2011 at a single institution. Patients with prolonged and recurrent POI were identified by review of hospital stay documentation by a fellowship-trained spine surgeon and a research fellow. POI patients were matched 1:1 to a control cohort without POI. Uni- and multivariate analyses were performed on demographic, comorbidity, surgical indication, medication, and perioperative details to identify independent risk factors for POI. RESULTS: Incidence of prolonged or recurrent POI after LLIF was 7.0% (42/596). Postoperative length of stay was significantly higher for patients with POI (9.9 ± 4.3 d) than control patients (5.6 ± 4.1 d) (P < 0.001). The incidence of ileus in the first 100 LLIF cases (11%) was not significantly higher than in the last 100 LLIF cases (6%) (P = 0.21). Independent risk factors were history of gastroesophageal reflux disease (P < 0.01, adjusted odds ratio [aOR]: 24.31), posterior instrumentation (P = 0.002, aOR: 19.48), and LLIF at L1-L2 (P = 0.04, aOR: 7.82). A history of prior abdominal surgery approached significance as an independent protective factor (P = 0.07, aOR: 0.29). CONCLUSION: There was a relatively high incidence of POI after LLIF. Independent risk factors for POI were a history of gastroesophageal reflux disease, posterior instrumentation, and LLIF at L1-L2. A history of prior abdominal surgery approached significance as an independent protective factor. LEVEL OF EVIDENCE: 3.

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.