Complexity-functioning relationships differ across different environmental conditions.

Habitat complexity is widely considered an important determinant of biodiversity, and enhancing complexity can play a key role in restoring degraded habitats. However, the effects of habitat complexity on ecosystem functioning - as opposed to biodiversity and community structure - are relatively poorly understood for artificial habitats, which dominate many coastlines. With Greening of Grey Infrastructure (GGI) approaches, or eco-engineering, increasingly being applied around the globe, it is important to understand the effects that modifying habitat complexity has on both biodiversity and ecological functioning in these highly modified habitats. We assessed how manipulating physical (primary substrate) and/or biogenic habitat (bivalves) complexity on intertidal artificial substrata affected filtration rates, net and gross primary productivity (NPP and GPP, respectively) and community respiration (CR) - as well as abundance of filter feeders and macro-algae and habitat use by cryptobenthic fish across six locations in three continents. We manipulated both physical and biogenic complexity using 1) flat or ridged (2.5 cm or 5 cm) settlement tiles that were either 2) unseeded or seeded with oysters or mussels. Across all locations, increasing physical and biogenic complexity (5 cm seeded tiles) had a significant effect on most ecological functioning variables, increasing overall filtration rates and community respiration of the assemblages on tiles but decreasing productivity (both GPP and NPP) across all locations. There were no overall effects of increasing either type of habitat complexity on cryptobenthic fish MaxN, total time in frame or macro-algal cover. Within each location, there were marked differences in the effects of habitat complexity. In Hobart, we found higher filtration, filter feeder biomass and community respiration on 5 cm tiles compared to flat tiles. However, at this location, both macro-algae cover and GPP decreased with increasing physical complexity. Similarly in Dublin, filtration, filter feeder biomass and community respiration were higher on 5 cm tiles compared to less complex tiles. In Sydney, filtration and filter feeder biomass were higher on seeded than unseeded tiles, and fish MaxN was higher on 5 cm tiles compared to flat tiles. On unseeded tiles in Sydney, filter feeder biomass also increased with increasing physical complexity. Our findings suggest that GGI solutions via increased habitat complexity are likely to have trade-offs among potentially desired functions, such as productivity and filtration rates, and variable effects on cryptobenthic fish communities. Importantly, our results show that the effects of GGI practices can vary markedly according to the environmental context and therefore should not be blindly and uniformly applied across the globe.

Characterizing utilization patterns and reoperation risk factors of interspinous process devices: analysis of a national claims database.

INTRODUCTION: Interspinous process devices (IPDs) were developed as minimally invasive alternatives to open decompression surgery for spinal stenosis. However, given high treatment failure and reoperation rates, there has been minimal adoption by spine surgeons. This study leveraged a national claims database to characterize national IPD usage patterns and postoperative outcomes after IPD implantation. METHOD: Using the PearlDiver database, we identified all patients who underwent 1- or 2-level IPD implantation between 2010 and 2018. Univariate and multivariable logistic regression was performed to identify predictors of the number of IPD levels implanted and reoperation up to 3 years after the index surgery. Right-censored Kaplan-Meier curves were plotted for duration of reoperation-free survival and compared with log-rank tests. RESULTS: Patients (n = 4865) received 1-level (n = 3246) or 2-level (n = 1619) IPDs. Patients who were older (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.01-1.03, P < .001), male (aOR 1.31, 95% CI 116-1.50, P < .001), and obese (aOR 1.19, 95% CI 1.05-1.36, P < .01) were significantly more likely to receive a 2-level IPD than to receive a 1-level IPD. The 3-year reoperation rate was 9.3% of patients when mortality was accounted for during the follow-up period. Older age decreased (aOR 0.97, 95% CI 0.97-0.99, P = .0039) likelihood of reoperation, whereas 1-level IPD (aOR 1.37, 95% CI 1.01-1.89, P = .048), Charlson Comorbidity Index (aOR 1.07, 95% CI 1.01-1.14, P = .018), and performing concomitant open decompression increased the likelihood of reoperation (aOR 1.68, 95% CI 1.35-2.09, P = .0014). CONCLUSION: Compared with 1-level IPDs, 2-level IPDs were implanted more frequently in older, male, and obese patients. The 3-year reoperation rate was 9.3%. Concomitant open decompression with IPD placement was identified as a significant risk factor for subsequent reoperation and warrants future investigation.

Evaluating Surgical Cervical Arthrodesis With a Novel MRI Grading Score.

STUDY DESIGN: This was a single-institution retrospective study. OBJECTIVE: Evaluate a magnetic resonance imaging (MRI)-scoring system to differentiate arthrodesis from pseudoarthrosis following anterior cervical discectomy and fusion. SUMMARY OF BACKGROUND DATA: Diagnostic workup following fusion surgery often includes MRI to evaluate neural structures and computed tomography (CT) and/or dynamic x-rays to evaluate instrumentation and arthrodesis. The use of MRI alone for these evaluations would protect patients from harmful CT and x-ray ionizing radiation. METHODS: Neurosurgical attending evaluated CTs for arthrodesis or pseudoarthrosis. Blinded neuroradiology attending and neurosurgery senior resident evaluated independent T1 and T2 region of interest (ROI) signal intensity over instrumented disk space. Cerebral spinal fluid (CSF) at the cisterna magnum and distal adjacent uninstrumented vertebral body (VB) were also calculated. ROI interspace /ROI CSF and ROI interspace /ROI VB quotients were used to create T1- and T2-interspace interbody scores (IIS). RESULTS: Study population (n=64 patients, 50% female) with a mean age of 51.72 years and 109 instrumented levels with 45 fused levels (41.3%) were included. T1-weighted MRI, median T1-IIS CSF for arthrodesis was 176.20 versus 130.92 for pseudoarthrosis ( P <0.0001), T1-IIS VB for arthrodesis was 68.52 and pseudoarthrosis was 52.71 ( P <0.0001). T2-weighted MRI, median T2-IIS CSF for arthrodesis was 27.72 and 14.21 for pseudoarthrosis ( P <0.0001), while T2-IIS VB for arthrodesis was 67.90 and 41.02 for pseudoarthrosis ( P <0.0001). The greatest univariable discriminative capability for arthrodesis via AUROC was T1-IIS VB (0.7743). CONCLUSION: We describe a novel MRI scoring system that may help determine arthrodesis versus pseudoarthrosis following anterior cervical discectomy and fusion. Postoperative symptomatic patients may only require MRI, which would protect patients from ionizing radiation. LEVEL OF EVIDENCE: Level IV.

Low-Cost Wound Healing Protocol Reduces Infection and Reoperation Rates After Cranioplasty: A Retrospective Cohort Study.

BACKGROUND AND OBJECTIVES: Cranioplasty infections are a common and expensive problem associated with significant morbidity. Our objective was to determine whether a wound healing protocol after cranioplasty reduced the rate of infections and to determine the value of this intervention. METHODS: This is a single-institution retrospective chart review of 2 cohorts of cranioplasty patients over 12 years. The wound healing protocol, consisting of vitamin and mineral supplementation, fluid supplementation, and oxygen support, was instituted for all patients aged older than 15 years undergoing cranioplasty. We retrospectively reviewed the charts of all patients over the study period and compared outcomes before and after protocol institution. Outcomes included surgical site infection, return to operating room within 30 days, and cranioplasty explant. Cost data were collected from the electronic medical record. We included 291 cranioplasties performed before the wound healing protocol and 68 postprotocol. RESULTS: Baseline demographics and comorbidities were comparable between preprotocol and postprotocol groups. Odds of takeback to operating room within 30 days were the same before and after the wound healing protocol (odds ratio [OR] 2.21 [95% CI 0.76-6.47], P = .145). Odds of clinical concern for surgical site infection were significantly higher in the preprotocol group (OR 5.21 [95% CI 1.22-22.17], P = .025). Risk of washout was higher in the preprotocol group (HR 2.86 [95% CI 1.08-7.58], P = .035). Probability of cranioplasty flap explant was also significantly higher in the preprotocol group (OR 4.70 [95% CI 1.10-20.05], P = .036). The number needed to treat to prevent 1 cranioplasty infection was 24. CONCLUSION: A low-cost wound healing protocol was associated with reduced rate of infections after cranioplasty with concomitant reduction in reoperations for washout, saving the health care system more than $50,000 per 24 patients. Prospective study is warranted.

Early postoperative MRI findings following anterior cervical discectomy and fusion: What to expect when the unexpected happens.

Background: Magnetic resonance imaging (MRI) is not routinely ordered following spinal fusion. Some literature suggests MRIs are unhelpful due to postoperative changes that obscure interpretation. We aim to describe findings of acute postoperative MRI following anterior cervical discectomy and fusion (ACDF). Methods: The authors retrospectively analyzed adult MRIs completed within 30 days of ACDF (from 2005-2022). T1 and T2 signal intensity in the interbody space dorsal to the graft, mass effect on the dura/spinal cord, intrinsic spinal cord T2 signal, and interpretability were reviewed. Results: In 38 patients there were 58 ACDF levels (1, 2, and 3 levels; 23, 10, and 5, respectively). MRIs were completed on mean postoperative day 8.37 (range; 0-30 days). T1-weighted imaging was described as isointense, hyperintense, heterogenous, and hypointense in 48 (82.8%), 5 (8.6%), 3 (5.2%), and 2 levels (3.4%), respectively. T2-weighted imaging was described as hyperintense, heterogenous, isointense, and hypointense in 41 (70.7%), 12 (20.7%), 3 (5.2%), and 2 levels (3.4%), respectively. There was no mass effect in 27 levels (46.6%), 14 (24.1%) had thecal sac compression, and 17 (29.3%) had cord compression. Conclusions: The majority of MRIs exhibited readily compression and intrinsic spinal cord signal even with various types of fusion constructs. Early MRI after lumbar surgery can be difficult to interpret. However, our results support the use of early MRI to investigate neurological complaints following ACDF. Our findings do not support the idea that epidural blood products and mass effect on the cord are seen in most postoperative MRIs after ACDF.

Possible association of trichorhinophalangeal syndrome I and intracranial subependymoma.

Trichorhinophalangeal syndromes (TRPSs) are rare hereditary syndromes with autosomal dominant inheritance. Patients exhibit abnormalities including bulbous pear-shaped nose, broad columella, and long and flat philtrum, fine, sparse, brittle, slow-growing scalp hair, skeletal abnormalities, and short stature. Three families; age at subependymoma surgery, pathogenic TRPS1(NM_014112.5) variant, and subependymoma number are described.

Minimally Invasive Preganglionic C2 Root Section for Occipital Neuralgia: 2 Case Reports and Operative Video.

BACKGROUND: Occipital neuralgia is a painful condition that is believed to occur from processes that affect the greater, lesser, or third occipital nerves. Diagnosis is often made with a combination of classical symptoms, tenderness over the occipital region, and response to occipital nerve blocks. Cervical computed tomography or MRI may be obtained in multiple positions to detect any impingement. Diagnosis can be made with MRI tractography. Nonsurgical treatments include local anesthetic and steroid injections, anticonvulsant medications, botulinum toxin injections, physical therapy, acupuncture, transcutaneous electrical stimulation, cryoneurolysis, and radiofrequency ablation. Surgical treatments include greater occipital nerve decompression, C2 root section, intradural dorsal root rhizotomy, C1-2 fusion, and occipital nerve stimulation. Although stimulation has been favored in the past decade, complications and maintenance of the devices have led us to return to C2 ganglionectomy. OBJECTIVE: To report on the use of a minimally invasive technique for C2 ganglionectomy to treat occipital neuralgia. METHODS: Review demographic, surgery, and outcome data of a minimally invasive C2 root ganglionectomy used to treat to 2 patients with occipital neuralgia. RESULTS: We report on 2 patients with clinically stereotypical unilateral occipital neuralgia confirmed by greater occipital nerve block, but with no imaging correlate. Both were successfully managed by C2 ganglionectomy through an 18-mm tubular retractor and outpatient surgery. Accompanying text, still photographs, and video describe the technique in detail. CONCLUSION: Minimally invasive C2 ganglionectomy can be used to successfully treat occipital neuralgia.

Utilization of Vertebroplasty/Kyphoplasty in the Management of Compression Fractures: National Trends and Predictors of Vertebroplasty/Kyphoplasty.

OBJECTIVE: The purpose of this study is to examine the utilization of kyphoplasty/vertebroplasty procedures in the management of compression fractures. With the growing elderly population and the associated increase in rates of osteoporosis, vertebral compression fractures have become a daily encounter for spine surgeons. However, there remains a lack of consensus on the optimal management of this patient population. METHODS: A retrospective analysis of 91 million longitudinally followed patients from 2016 to 2019 was performed using the PearlDiver Patient Claims Database. Patients with compression fractures were identified using International Classification of Disease, 10th Revision codes, and a subset of patients who received kyphoplasty/vertebroplasty were identified using Common Procedural Terminology codes. Baseline demographic and clinical data between groups were acquired. Multivariable regression analysis was performed to determine predictors of receiving kyphoplasty/vertebroplasty. RESULTS: A total of 348,457 patients with compression fractures were identified with 9.2% of patients receiving kyphoplasty/vertebroplasty as their initial treatment. Of these patients, 43.5% underwent additional kyphoplasty/vertebroplasty 30 days after initial intervention. Patients receiving kyphoplasty/vertebroplasty were significantly older (72.2 vs. 67.9, p < 0.05), female, obese, had active smoking status and had higher Elixhauser Comorbidity Index scores. Multivariable analysis demonstrated that female sex, smoking status, and obesity were the 3 strongest predictors of receiving kyphoplasty/vertebroplasty (odds ratio, 1.27, 1.24, and 1.14, respectively). The annual rate of kyphoplasty/vertebroplasty did not change significantly (range, 8%-11%). CONCLUSION: The majority of vertebral compression fractures are managed nonoperatively. However, certain patient factors such as smoking status, obesity, female sex, older age, osteoporosis, and greater comorbidities are predictors of undergoing kyphoplasty/vertebroplasty.

The environmental crisis and the film First Reformed: Paths to paralysis and change.

The natural world has always been integral to our existence; currently, we are compelled to reckon with our assumptions about this connection with mounting urgency. Individual reactions to the environment are influenced not only by the sociocultural surround, but also by one's internal world, particularly whether one's internal objects are felt to have been irreparably damaged or are potentially salvageable. Excessive guilt about destructive impulses can limit one's ability to recognize individual responsibility for the current situation without catastrophizing the weight of one's ecological footprint. Delusional solutions may be adopted, valorizing extreme forms of engagement. The film First Reformed illustrates what appear to be divergent approaches to the planet: ruthless exploitation by an industrialist versus an impassioned objection to destruction of the environment for economic gain. In this narrative, both are underpinned by a paranoid-schizoid mindset. We investigate the dynamics of this psychic state, which results in a constricted perception and an absence of constructive agency with respect to the environmental crisis. We present an alternative conceptualization of the natural world's place within a person's psychic equilibrium. We emphasize that a more integrated relationship with the environment can facilitate concerned, preservative action on behalf of the natural world and ourselves.

Minimally Invasive Posterior Cervical Diskectomy: Operative Video.

Cervical disk protrusion is a common pathology. Anterior diskectomy and fusion is considered the gold standard of treatment, although anterior arthroplasty has gained some acceptance in the past decade as an alternative. Posterior cervical minimally invasive diskectomy is a rarely used technique, and there is less literature discussing this procedure. We have found this technique to be useful in lateral, soft disk herniations not ventral to the cord or mineralized. This avoids an anterior approach with risk to the cervical viscera, the dysphagia associated with an anterior approach, the need for expensive implanted instrumentation, and the need for prolonged activity restrictions after an anterior approach. We include a Video 1 documenting the technique of minimally invasive posterior cervical diskectomy (anatomic landmarks of interest are labeled at several points during the video). This is achieved prone on an OSI Jackson table (Mizuho OSI, Union City, California, USA) without skeletal fixation. A stepwise technique is used to advance an 18-mm tube retractor into contact with the facet and lateral lamina. A 5-mm smooth diamond drill is used to perform a foraminotomy. To avoid nerve root or spinal cord manipulation, it is often necessary to remove some of the rostral aspect of the inferior pedicle to gain access to the axilla and disk protrusion. The procedure is rapid, well tolerated, and performed as outpatient, and it results in a rapid return to normal activity.

Long-term monitoring of Vermont's forest soils: early trends and efforts to address innate variability.

Long-term monitoring of forest soils is necessary to understand the effects of continued environmental change, including climate change, atmospheric deposition of metals, and, in many regions, recovery from acidic precipitation. A monitoring program was initiated in 2002 at five protected forest sites, primarily Spodosol soils, in Vermont, northeastern USA. Every 5 years, ten soil pits were sampled from random subplots in a 50 × 50-m plot at each site. Samples were taken by genetic horizon and, to reduce variability and improve comparability, from four specific layers: the combined Oi/Oe layer, the combined Oa/A layer, the top 10 cm of the B horizon, and 60-70 cm below the soil surface (usually the C horizon). The samples were archived and a subset analyzed for carbon, nitrogen, and exchangeable cations. After four sampling campaigns, the average coefficients of variation (CVs) at each site had a broad range, 10.7% for carbon in the Oa/A horizon to 84.3% for exchangeable Ca2+ in the B horizon. An investigation of variability within the upper 10 cm of the B horizon across a 90-cm soil pit face showed similar CVs to the entire site, emphasizing the need for consistent and careful sampling. After 15 years, temporal trends were significant in the Oa/A and B horizons at two of the five sites, with one site showing an increase in carbon concentration in both layers along with increases in both exchangeable Ca2+ and Al3+ in the B horizon, perhaps linked to recovery from acidification. The monitoring program plans to continue at 5-year intervals for the next century.

Association of Preoperative Hemoglobin A1c and Body Mass Index with Wound Infection Rate in Spinal Surgery.

BACKGROUND: The deleterious effect of diabetes mellitus on surgical outcomes is well documented for joint replacement surgery. We analyzed the large national US Department of Veterans Affairs (VA) database for patients who had undergone elective spinal surgery. METHODS: We retrospectively searched the VA database and identified 174 520 spine cases. RESULTS: There were 7766 (4.5%) wound infections and 49 271 (28%) had hemoglobin A1c (HbA1c) testing (range: 3.0-17.8) prior to surgery. In the preoperative HbA1c-checked group, there were 2941 (6.0% of 49 271) infections and in the without-preoperative HbA1c group, there were 4825 (3.9% of 125 249) infections. The distribution of infections was significantly different (χ2 = 372.577, P < .0001) and suggests a 2.12% increase in the absolute risk of infection based on the presence of preoperative HbA1c testing, regardless of the result. Logistic regression revealed a preoperative HbA1c test was associated with an odds ratio of 1.435 for infection (confidence interval 1.367-1.505, P < .0001). In a separate model based on HbA1c levels, we found that HbA1c is a significant predictor of infection with an odds ratio of 1.042 (confidence interval 1.017-1.068, P = .0009) for each 1% increase in the test result. This analysis differs from using a strict cutoff value of HbA1c of 6.5%. Similar testing for body mass index and age yielded an odds ratio of 1.027 for each increase of 1 kg/m2 and an odds ratio of 1.009 for each 1-year increase in age respectively. CONCLUSIONS: Hemoglobin A1c testing, HgA1c value, body mass index, and age all contribute to the risk of wound infection after elective spine surgery in a large national VA population. These data can be used to estimate surgical risks and to aid in patient counseling about proposed spine surgery. LEVEL OF EVIDENCE: 4.

Trends in Weight and Body Mass Index after Spinal Surgery for Degenerative Disease.

BACKGROUND: Currently, 37% of adults in the United States are obese, and 34% are overweight. Obesity poses a particularly complex challenge in spinal surgery management, whereby risk of adverse surgical outcomes increases with increased body mass index (BMI). When patients are counseled to reduce weight to levels associated with acceptable surgical risks, patients often respond that their spinal problems prohibit the exercise needed to lose the required weight and counter that surgery will allow for increased activity and thereby facilitate weight loss. A retrospective study of a US Veterans Affairs (USVA) nationwide patient database was undertaken. METHODS: A request was made of the USVA Corporate Data Warehouse for data on all patients undergoing elective spine surgery for degenerative conditions over a 10-year period. RESULTS: The mean preoperative age of 65 667 patients identified was 59 years. The mean preoperative weight was 91.8 kg, and BMI was 29.2. Before surgery, 26 772 patients had a BMI of >30. After surgery, 12 564 (46.9%) lost at least 2.3 kg, 9450 (35.3%) gained at least 2.3 kg, and 4758 (17.8%) were unchanged. After surgery, 4853 (18.1%) lost at least 11.3 kg and 1360 (5.1%) lost at least 22.7 kg. At a mean of 1.9 years after index surgery, mean postoperative weight was 92.5 kg, and BMI was 29.4. Of the 65 667 patients, 23 125 (35.2%) patients lost at least 2.3 kg, 27 571 (42.0%) gained at least 2.3 kg, and 14 971 (23.0%) remained within 2.3 kg of their preoperative weight. CONCLUSION: The study results will aid in counseling patients regarding realistic expectations about weight loss after spinal surgery. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: This evidence will allow for realistic patient counseling regarding the likelihood of weight loss after elective spinal surgery.

The Cost of Cancer: The Association of Financial and Cancer-Related Stress on Maladaptive Coping Styles in Families with a Cancer Diagnosis.

According to the American Cancer Society (2020), it is estimated that 1.8 million new cancer diagnoses will occur in 2019 in the United States. Due to the frequency of cancer diagnoses and the increasing costs of treatment, financial stress is common among cancer patients. Guided by the Family Systems Illness Model (FSI), a cross-sectional study of individuals and family members where there was an active cancer diagnosis (n = 53) was conducted. The study utilized structural equation modeling to examine the impact of cancer stress and financial stress on maladaptive family coping mechanisms, and in turn, their effect on family communication and satisfaction. Findings indicate individuals with higher financial stress reported greater cancer stress. In turn, individuals with higher cancer stress, reported higher rigidity in their family coping which was associated with less family satisfaction. Additionally, as individuals reported greater family disengagement and chaos, lower levels of family communication and satisfaction were found. These findings provide evidence to the complex stresses experienced by cancer patients and their families. Therapeutic implications of how emotionally focused therapy may support these families dealing with a cancer diagnosis are discussed.

Lumbar Fusion With Polyetheretherketone Rods Use for Patients With Degenerative Disease.

INTRODUCTION: Polyetheretherketone (PEEK) rods for lumbar fusion have been available since 2007. However, literature about their utility is sparse and of mixed outcomes. METHODS: A retrospective review of PEEK rod lumbar fusion cases was performed. Data were analyzed from 108 patients of the senior author Donald Ross who underwent PEEK lumbar fusion. RESULTS: There were 97 single and 11 2-level fusions. Rates of tobacco use, diabetes mellitus, low bone density, depression, and immunosuppression were 23.1%, 24.1%, 14.8%, 32.4%, and 6.5%, respectively. In the study population, the mean age was 60.2 years, body mass index was 30.1, and there was a mean 31.3 months for follow-up. There were no wound infections or new neurologic deficits. Of 81 patients with > 11 months of follow-up, 70 (86.4%) had an arthrodesis, 8 (9.9%) had no arthrodesis, and 3 (3.7%) were indeterminate. No patients had revision fusion surgery and 2 patients had adjacent level fusions at 27 and 60 months. One patient had an adjacent segment laminectomy at 18 months and one a foraminotomy at 89 months, resulting in a 3.7% adjacent segment surgery rate. Mean preoperative Short Form-36 (SF-36) physical functioning (PF) score and Oswestry Disability Index (ODI) score were 28.9 and 24.8, respectively. Mean SF-36 PF postoperative score at 1 and 2 years were 59.3 and 65, respectively. Mean ODI postoperative score at 1 year was 14.5. CONCLUSIONS: In a large patient cohort lumbar fusion with PEEK rods can be undertaken with low complication rates, satisfactory clinical improvements, low rates of hardware failure or need for revision surgery. Longer follow-up is needed to confirm findings.

Land use and landscape position influence soil organic phosphorus speciation in a mixed land use watershed.

Land use can significantly alter soil P forms, which will influence P loss in runoff. Organic P (Po ) compounds are an important component of soil P, but their forms and cycling in soils with different land uses are still poorly understood. In addition, streambanks are potential sources of P loss; P forms and concentrations in streambank soils may vary with land use, affecting potential P loss to water. This study used solution 31 P nuclear magnetic resonance spectroscopy to characterize and quantify P in interior and streambank soils (0-10 cm) under duplicate sites from four different land uses along streams in the Missisquoi River basin (VT, USA): silage corn, hay meadow, emergent wetlands, and forest. Orthophosphate monoesters were the dominant P compound class regardless of land use or landscape position. Forest soils had the lowest Po concentrations, less labile P forms than other soils, and significantly lower concentrations of total inositol hexakisphosphates and total orthophosphate monoesters compared with corn soils. Riparian buffer zones for agricultural soils lowered P concentrations in streambank soils for many soil P pools relative to interior soils. The wetland soils of this study had P concentrations and P forms that were similar to those for interior agricultural soils and generally showed no reduction in P concentrations in streambank soils relative to interior soils. This is consistent with the role of wetlands as P sinks in the landscape but also suggests these wetlands should be carefully monitored to minimize P accumulation, especially in streambank soils.

Anterior Cervical Arthrodesis With Polyetheretherketone Spacers: What is the Role of the Grafting Material?

STUDY DESIGN: This was a retrospective study of 2 surgeons' use of a single polyetheretherketone (PEEK) device. OBJECTIVE: Our objective was to investigate the fusion adjunct placed within PEEK devices to examine the likelihood of an arthrodesis, regardless of the PEEK interbody device itself. SUMMARY OF BACKGROUND DATA: The effectiveness of PEEK interbody devices in anterior cervical arthrodesis has been questioned. METHODS: The authors retrospectively reviewed the results of 121 patients with demineralized bone matrix (DBM) and 96 with local autograft bone placed within identical PEEK devices for anterior cervical arthrodesis (from 2011 to 2018); 1 surgeon used DBM and another local autograft bone. Arthrodesis was determined independently by a surgeon and 2 blinded neuroradiologists. RESULTS: For DBM versus autograft; mean age was 60 versus 61 years, smoking status 42.1% versus 31%, diabetes mellitus 18.2% versus 28%, mean body mass index 31 versus 30, and follow up averaged 17 months in both groups. For DBM versus autograft; a radiographic arthrodesis was observed in 22.3% versus 76% of patients. Refusion at the index level was required in 5.8% of the DBM and 0% of the autograft patients. CONCLUSIONS: A PEEK interbody device filled with local autograft resulted in a higher radiographic fusion rate and a lower need for reoperation at the index level than an identical device filled with DBM. Caution is warranted in assigning fusion failure to the PEEK device alone in anterior cervical discectomy and fusion surgery.

Morphological changes of the dorsal contour of the corpus callosum during the first two years of life.

BACKGROUND: In the medicolegal literature, focal concavities or notching of the corpus callosum has been thought to be associated with fetal alcohol spectrum disorders. Recent work suggests corpus callosum notching is a dynamic and normal anatomical feature, although it has not yet been defined in early life or infancy. OBJECTIVE: Our purpose was to characterize the dorsal contour of the corpus callosum during the first 2 years of life by defining the prevalence, onset and trajectory of notching on midsagittal T1-weighted images. MATERIALS AND METHODS: We reviewed retrospectively 1,157 consecutive patients between birth and 2 years of age. Corpus callosum morphology was evaluated and described. A notch was defined as a dorsal concavity of at least 1 mm in depth along the dorsal surface of the corpus callosum. Patient age as well as notch depth, location, number and presence of the pericallosal artery in the notch were noted. RESULTS: Two hundred thirty-three notches were identified in 549 patients: 36 anterior, 194 posterior and 3 patients with undulations. A statistically significant (R2=0.53, Beta=0.021, P=0.002) positive correlation between posterior notch prevalence and age in months was noted. A positive correlation between age and depth of the posterior notch was also statistically significant (r=0.32, n=179, P≤0.001). A trend for increased anterior notch prevalence with age was identified with significant correlation between visualized pericallosal artery indentation and anterior notching (r=0.20, n=138, P=0.016). Sub-analysis of the first month of life showed corpus callosum notching was not present. CONCLUSION: The presence of posterior notching increased significantly with age and was more frequent than that of anterior notching. Corpus callosum notching was absent in the first week of life, building on prior studies suggesting corpus callosum notching is acquired. This study provides baseline data on normative corpus callosum notching trajectories by age group during early life, a helpful correlate when associating corpus callosum morphology with disease.