Incidence and Outcomes of Acute Implant Extrusion Following Anterior Cervical Spine Surgery.

STUDY DESIGN: Multi-institutional retrospective case series of 8887 patients who underwent anterior cervical spine surgery. OBJECTIVE: Anterior decompression from discectomy or corpectomy is not without risk. Surgical morbidity ranges from 9% to 20% and is likely underreported. Little is known of the incidence and effects of rare complications on functional outcomes following anterior spinal surgery. In this retrospective review, we examined implant extrusions (IEs) following anterior cervical fusion. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of 21 predefined treatment complications. RESULTS: Following anterior cervical fusion, the incidence of IE ranged from 0.0% to 0.8% across 21 institutions with 11 cases reported. All surgeries involved multiple levels, and 7/11 (64%) involved either multilevel corpectomies or hybrid constructs with at least one adjacent discectomy to a corpectomy. In 7/11 (64%) patients, constructs ended with reconstruction or stabilization at C7. Nine patients required surgery for repair and stabilization following IE. Average length of hospital stay after IE was 5.2 days. Only 2 (18%) had residual deficits after reoperation. CONCLUSIONS: IE is a very rare complication after anterior cervical spine surgery often requiring revision. Constructs requiring multilevel reconstruction, especially at the cervicothoracic junction, have a higher risk for failure, and surgeons should proceed with caution in using an anterior-only approach in these demanding cases. Surgeons can expect most patients to regain function after reoperation

Modeling speed restrictions to mitigate lethal collisions between ships and whales

a b s t r a c t Collision with ships is a significant cause of mortality among endangered whales. Collision lethality increases with vessel speed and mitigation includes slowing ships in whale dense areas. The 2181 km 2 Stellwagen Bank National Marine Sanctuary (SBNMS) is a site of numerous whale/ship collisions. To understand how speed reduction measures reduce lethal collisions, we used GIS to apply hypothetical speed reductions to observed ship traffic within SBNMS. During 2006, we collected complete AIS data from SBNMS vessel traffic. We created 1.85 km 2 (N = 810) grid cells covering SBNMS and determined each cell's predicted probability of lethality (PLETH) from the cell's mean speed and a mortality curve. We calculated average PLETH for the entire sanctuary (SPLETH), and used SPLETH to index status quo risk. We applied speed limits of 16, 14, 12, and 10 knots on transits and recalculated SPLETH for each scenario. Our analysis included 2,079,867 AIS points to derive 74,638 cell transits by 502 ships (>295 t). Sanctuary mean ship speed, by cell transit, was 13.5 knots (SD4.3, range 0.1-42.2). The choice of speed restriction had a major impact on SPLETH: 16 knots = À3.7%, 14 knots = À11%, 12 knots = À29.4%, 10 knots = À56.7%. The conservation benefit of speed restrictions is influenced by the status quo speed of ships from which risk must be reduced. As most areas lack such data our results can provide managers with a better understanding of how speed restrictions might reduce risk in their waters. Published by Elsevier Ltd

Epidemiology and Outcomes of Vertebral Artery Injury in 16 582 Cervical Spine Surgery Patients: An AOSpine North America Multicenter Study.

STUDY DESIGN: A multicenter retrospective case series was compiled involving 21 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005 and 2011 and who sustained a vertebral artery injury (VAI). OBJECTIVE: To report the frequency, risk factors, outcomes, and management goals of VAI in patients who have undergone cervical spine surgery. METHODS: Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36). RESULTS: VAIs were identified in a total of 14 of 16 582 patients screened (8.4 per 10 000). The mean age of patients with VAI was 59 years (±10) with a female predominance (78.6%). Patient diagnoses included myelopathy, radiculopathy, cervical instability, and metastatic disease. VAI was associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior-only approach, 3 cases with posterior-only approach, and 4 during circumferential approach. Fifty percent of cases of VAI with available preoperative imaging revealed anomalous vessel anatomy during postoperative review. Average length of hospital stay was 10 days (±8). Notably, 13 of the 14 (92.86%) cases resolved without residual deficits. Compared to preoperative baseline NDI, Nurick, mJOA, and SF-36 scores for these patients, there were no observed changes after surgery (P = .20-.94). CONCLUSIONS: Vertebral artery injuries are potentially catastrophic complications that can be sustained from anterior or posterior cervical spine approaches. The data from this study suggest that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits

Rare Complications of Cervical Spine Surgery: Pseudomeningocoele.

STUDY DESIGN: This study was a retrospective, multicenter cohort study. OBJECTIVES: Rare complications of cervical spine surgery are inherently difficult to investigate. Pseudomeningocoele (PMC), an abnormal collection of cerebrospinal fluid that communicates with the subarachnoid space, is one such complication. In order to evaluate and better understand the incidence, presentation, treatment, and outcome of PMC following cervical spine surgery, we conducted a multicenter study to pool our collective experience. METHODS: This study was a retrospective, multicenter cohort study of patients who underwent cervical spine surgery at any level(s) from C2 to C7, inclusive; were over 18 years of age; and experienced a postoperative PMC. RESULTS: Thirteen patients (0.08%) developed a postoperative PMC, 6 (46.2%) of whom were female. They had an average age of 48.2 years and stayed in hospital a mean of 11.2 days. Three patients were current smokers, 3 previous smokers, 5 had never smoked, and 2 had unknown smoking status. The majority, 10 (76.9%), were associated with posterior surgery, whereas 3 (23.1%) occurred after an anterior procedure. Myelopathy was the most common indication for operations that were complicated by PMC (46%). Seven patients (53%) required a surgical procedure to address the PMC, whereas the remaining 6 were treated conservatively. All PMCs ultimately resolved or were successfully treated with no residual effects. CONCLUSIONS: PMC is a rare complication of cervical surgery with an incidence of less than 0.1%. They prolong hospital stay. PMCs occurred more frequently in association with posterior approaches. Approximately half of PMCs required surgery and all ultimately resolved without residual neurologic or other long-term effects

Patient Navigators Connecting Patients to Community Resources to Improve Diabetes Outcomes

BACKGROUND: Despite the recognized importance of lifestyle modification in reducing risk of developing type 2 diabetes and in diabetes management, the use of available community resources by both patients and their primary care providers (PCPs) remains low. The patient navigator model, widely used in cancer care, may have the potential to link PCPs and community resources for reduction of risk and control of type 2 diabetes. In this study we tested the feasibility and acceptability of telephone-based nonprofessional patient navigation to promote linkages between the PCP office and community programs for patients with or at risk for diabetes. METHODS: This was a mixed-methods interventional prospective cohort study conducted between November 2012 and August 2013. We included adult patients with and at risk for type 2 diabetes from six primary care practices. Patient-level measures of glycemic control, diabetes care, and self-efficacy from medical records, and qualitative interview data on acceptability and feasibility, were used. RESULTS: A total of 179 patients participated in the study. Two patient navigators provided services over the phone, using motivational interviewing techniques. Patient navigators provided regular feedback to PCPs and followed up with the patients through phone calls. The patient navigators made 1028 calls, with an average of 6 calls per patient. At follow-up, reduction in HbA1c (7.8 ± 1.9% vs 7.2 ± 1.3%; P = .001) and improvement in patient self-efficacy (3.1 ± 0.8 vs 3.6 ± 0.7; P < .001) were observed. Qualitative analysis revealed uniformly positive feedback from providers and patients. CONCLUSIONS: The patient navigator model is a promising and acceptable strategy to link patient, PCP, and community resources for promoting lifestyle modification in people living with or at risk for type 2 diabetes

Exposure to Tobacco Smoke and Chronic Asthma Symptoms

The objective was to determine if tobacco exposure is associated with year-round asthma symptoms. We analyzed baseline data from a multistate survey of 896 pediatric patients with asthma participating in a randomized controlled trial. Daytime symptoms, nocturnal symptoms, and limitations in activity because of asthma tend to increase during the winter season (p < 0.05 for all comparisons, except spring to winter daytime symptoms). One hundred forty of 896 (16%) children had year-round symptoms (i.e., active asthma symptoms during every season). Using separate multivariate analyses, we found that having a parent who smokes (odds ratio [OR]: 2.22; 95% confidence interval [CI]: 1.35, 3.64) or a member of the household who smokes (OR: 1.94; 95% CI: 1.29, 2.93) was associated with a higher likelihood of year-round symptoms, controlling for region of residence, insurance status, and use of a daily controller medication. Asthma symptoms are more likely to increase in the winter season. In anticipation of these patterns, clinicians should consider initiating controller medication therapy or reinforcing asthma education prior to these time periods for those patients at risk for seasonal exacerbations. Exposure to tobacco smoke is associated with year-round asthma symptoms, highlighting the importance of health care providers identifying and counseling about smoking cessation, especially for children with year-round asthma symptoms. (Pediatr Asthma Immunol 2005; 18[4]:180–188.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63404/1/pai.2005.18.180.pd

Sources of Variation in Sweat Chloride Measurements in Cystic Fibrosis

Rationale: Expanding the use of cystic fibrosis transmembrane conductance regulator (CFTR) potentiators and correctors for the treatment of cystic fibrosis (CF) requires precise and accurate biomarkers. Sweat chloride concentration provides an in vivo assessment of CFTR function, but it is unknown the degree to which CFTR mutations account for sweat chloride variation

FAD binding, cobinamide binding and active site communication in the corrin reductase (CobR)

Adenosylcobalamin, the coenzyme form of vitamin B12, is one Nature's most complex coenzyme whose de novo biogenesis proceeds along either an anaerobic or aerobic metabolic pathway. The aerobic synthesis involves reduction of the centrally chelated cobalt metal ion of the corrin ring from Co(II) to Co(I) before adenosylation can take place. A corrin reductase (CobR) enzyme has been identified as the likely agent to catalyse this reduction of the metal ion. Herein, we reveal how Brucella melitensis CobR binds its coenzyme FAD (flavin dinucleotide) and we also show that the enzyme can bind a corrin substrate consistent with its role in reduction of the cobalt of the corrin ring. Stopped-flow kinetics and EPR reveal a mechanistic asymmetry in CobR dimer that provides a potential link between the two electron reduction by NADH to the single electron reduction of Co(II) to Co(I)

Assigning hydrogen, carbon, and nitrogen isotope values for phytoplankton and terrestrial detritus in aquatic food web studies

Studies designed to assess the resources supporting aquatic consumers using stable isotope analysis require measurements of the potential end members (basal resources). While some basal resources are easily measured, it is often difficult to physically separate phytoplankton (one potential end member) from other components in seston. Further, terrestrial materials entering aquatic ecosystems undergo diagenetic change, potentially altering isotope composition and making it difficult to assign end member values. We tested techniques for determining the isotopic hydrogen (&delta;2H), carbon (&delta;13C), and nitrogen (&delta;15N) values of terrestrial and phytoplankton end members in seston. Long term in situ leaf decomposition experiments were performed. No appreciable change was found in the isotope values of degraded material (mean change 3.6&permil; for &delta;2H, 0.0&permil; for &delta;13C, and &minus;0.1&permil; for &delta;15N). We conclude that the isotope values of terrestrial plant material can be used to assign end members for terrestrial detritus. Using samples collected from 10 lakes with phytoplankton-dominated seston, we compared 3 published methods for estimating the &delta;13C and &delta;15N of phytoplankton. One method, which corrected bulk particulate organic matter (POM) isotope values based on a &delta;2H mixing model, accurately predicted measured phytoplankton &delta;13C. Another method, which used a C:N mixing model to correct bulk POM, also performed well. A new method, proposed here, modified seston isotope values using the difference in C:N of phytoplankton and terrestrial material in a &delta;2H mixing model and correctly predicted measured phytoplankton &delta;15N. We recommend estimating phytoplankton &delta;13C and &delta;15N by correcting bulk POM using a &delta;2H mixing model, with the C:N modification proposed here for &delta;15N

C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases.

STUDY DESIGN: A multicenter, retrospective review of C5 palsy after cervical spine surgery. OBJECTIVE: Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. METHODS: We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ(2) tests or Fisher exact tests for categorical variables. RESULTS: Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). CONCLUSION: C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date