Radiographic Predictors of Functional Outcome in Degenerative Lumbar Spondylolisthesis Surgery

Objective: To confirm the importance of sagittal spinal alignment on functional outcome with degenerative lumbar spondylolisthesis (DLS) surgery and to identify the radiographic parameters that predict functional outcomes after DLS surgery. Methods: Retrospective analysis of the prospectively collected functional and radiographic outcomes of the Canadian Spine Outcomes and Research Network DLS database. All patients underwent either decompression, posterolateral fusion or interbody fusion surgery with a minimum of one-year postoperative follow-up. Results: Most patients improve or remain unchanged in their sagittal spinal alignment regardless of surgery type with fusion procedures not experiencing statistically significantly improved alignment changes to decompression alone. By multiple linear regression adjusted for baseline patient age, body mass index, gender and preoperative presence of depression, worsening of a patient’s pelvic incidence-lumbar lordosis (LL) mismatch with any technique of DLS surgery was associated with a higher one-year postoperative ODI score R2 0.179 (95% CI 0.080, 0.415, p=0.004), back pain R2 0.152 (95% CI 0.021, 0.070, p 2 0.059 (95% CI 0.008, 0.066, p=0.014) score. Likewise, reduction of LL was associated with a higher ODI score R2 0.168 (-0.387, -0.024, p=0.027) and back pain R2 0.135 (95% CI -0.064, -0.010, p=0.007). Conclusions: This is the first work to examine DLS patients outside of extrapolated sagittal balance parameters from the adult scoliosis literature. Importantly, we show that any worsening in sagittal spinal alignment parameters with DLS surgery regardless of surgery type leads to poorer functional outcomes even among patients who remain within conventionally held appropriate sagittal balance

Seasonal patterns and controls on net ecosystem CO2 exchange in a boreal peatland complex

We measured seasonal patterns of net ecosystem exchange (NEE) of CO2 in a diverse peatland complex underlain by discontinuous permafrost in northern Manitoba, Canada, as part of the Boreal Ecosystems Atmosphere Study (BOREAS). Study sites spanned the full range of peatland trophic and moisture gradients found in boreal environments from bog (pH 3.9) to rich fen (pH 7.2). During midseason (July‐August, 1996), highest rates of NEE and respiration followed the trophic sequence of bog (5.4 to −3.9 μmol CO2 m−2 s−1) \u3c poor fen (6.3 to −6.5 μmol CO2 m−2 s−1) \u3c intermediate fen (10.5 to −7.8 μmol CO2 m−2 s−1) \u3c rich fen (14.9 to −8.7 μmol CO2m−2 s−1). The sequence changed during spring (May‐June) and fall (September‐October) when ericaceous shrub (e.g., Chamaedaphne calyculata) bogs and sedge (Carex spp.) communities in poor to intermediate fens had higher maximum CO2 fixation rates than deciduous shrub‐dominated (Salix spp. and Betula spp.) rich fens. Timing of snowmelt and differential rates of peat surface thaw in microtopographic hummocks and hollows controlled the onset of carbon uptake in spring. Maximum photosynthesis and respiration were closely correlated throughout the growing season with a ratio of approximately 1/3 ecosystem respiration to maximum carbon uptake at all sites across the trophic gradient. Soil temperatures above the water table and timing of surface thaw and freeze‐up in the spring and fall were more important to net CO2 exchange than deep soil warming. This close coupling of maximum CO2 uptake and respiration to easily measurable variables, such as trophic status, peat temperature, and water table, will improve models of wetland carbon exchange. Although trophic status, aboveground net primary productivity, and surface temperatures were more important than water level in predicting respiration on a daily basis, the mean position of the water table was a good predictor (r2 = 0.63) of mean respiration rates across the range of plant community and moisture gradients. Q10 values ranged from 3.0 to 4.1 from bog to rich fen, but when normalized by above ground vascular plant biomass, the Q10 for all sites was 3.3

A High Spatial Resolution Mid-Infrared Spectroscopic Study of the Nuclei and Star-Forming Regions in Luminous Infrared Galaxies

We present a high spatial (diffraction-limited) resolution (~0.3") mid-infrared (MIR) spectroscopic study of the nuclei and star-forming regions of 4 local luminous infrared galaxies (LIRGs) using T-ReCS on the Gemini South telescope. We investigate the spatial variations of the features seen in the N-band spectra of LIRGs on scales of ~100 pc, which allow us to separate the AGN emission from that of the star formation (SF). We compare our Gemini T-ReCS nuclear and integrated spectra of LIRGs with those obtained with Spitzer IRS. The 9.7um silicate absorption feature is weaker in the nuclei of the LIRGs than in the surrounding regions. This is probably due to the either clumpy or compact environment of the central AGN or young, nuclear starburst. We find that the [NeII] luminosity surface density is tightly and directly correlated with that of Pa-alpha for the LIRG star-forming regions (slope of 1.00+-0.02). Although the 11.3um PAH feature shows also a trend with Pa-alpha, this is not common for all the regions. We also find that the [NeII]\Pa-alpha ratio does not depend on the Pa-alpha equivalent width (EW), i.e., on the age of the ionizing stellar populations, suggesting that, on the scales probed here, the [NeII] emission line is a good tracer of the SF activity in LIRGs. On the other hand, the 11.3um PAH\Pa-alpha ratio increases for smaller values of the Pa-alpha EW (increasing ages), indicating that the 11.3um PAH feature can also be excited by older stars than those responsible for the Pa-alpha emission. Additional high spatial resolution observations are essential to investigate, in a statistical way, the star formation in local LIRGs at the smallest scales and to probe ultimately whether they share the same physical properties as high-z LIRGs, ULIRGs and submillimiter galaxies.Comment: 23 pages (apjstyle), 19 figures, accepted for publicacion in Ap

Published randomized controlled trials of surveillance in cancer patients - a systematic review

With solid tumor cancer survivorship increasing, the number of patients requiring post-treatment surveillance also continues to increase. This highlights the need for evidence-based cancer surveillance guidelines. Ideally, these guidelines would be based on combined high-quality data from randomized controlled trials (RCTs). We present a systematic review of published cancer surveillance RCTs in which we sought to determine the feasibility of data pooling for guideline development. We carried out a systematic search of medical databases for RCTs in which adult patients with solid tumors that had undergone surgical resection with curative intent and had no metastatic disease at presentation, were randomized to different surveillance regimens that assessed effectiveness on overall survival (OS). We extracted study characteristics and primary and secondary outcomes, and assessed risk of bias and validity of evidence with standardized checklist tools. Our search yielded 32,216 articles for review and 18 distinct RCTs were included in the systematic review. The 18 trials resulted in 23 comparisons of surveillance regimens. There was a highlevel of variation between RCTs, including the study populations evaluated, interventions assessed and follow-up periods for the primary outcome. Most studies evaluated colorectal cancer patients (11/18, [61%]). The risk of bias and validity of evidence were variable and inconsistent across studies. This review demonstrated that there is tremendous heterogeneity among RCTs that evaluate effectiveness of different postoperative surveillance regimens in cancer patients, rendering the consolidation of data to inform high-quality cancer surveillance guidelines unfeasible. Future RCTs in the field should focus on consistent methodology and primary outcome definition

Profound Trunnion Wear Resulting in Femoral Head-Neck Dissociation in Total Hip Arthroplasty

We describe a case of aseptic failure with profound femoral stem trunnion wear and femoral head dissociation nine years after initial primary total hip arthroplasty (THA) with the Stryker Accolade total hip arthroplasty system. Current guidelines for postoperative care and follow-up after THAs as potential intervention points for early detection of prosthetic joint failure are also reviewed

Damage Control Orthopaedics in Spinal Trauma

There has been a shift in the management of the polytrauma patients from early total care to damage control orthopaedics (DCO), whereby patients with borderline hemodynamic stability may be temporized with the use of external fixators, traction, or splinting with delayed osteosynthesis of fractures. Recently, there has been an increasing trend toward a middle ground approach of Early Appropriate Care for polytrauma patients. The concepts of DCO for the spine are less clear, and the management of trauma patients with combined pelvic ring and spinal fractures or patients with noncontiguous spinal injuries present unique challenges to the surgeon in prioritization of patient needs. This review outlines the concept of DCO and Early Appropriate Care in the spine, prioritizing patient needs from the emergency department to the operating room. Concepts include the timing of surgery, minimally invasive versus open techniques, and the prioritization of spinal injuries in the setting of other orthopaedic and nonorthopaedic injuries. Contiguous and noncontiguous spinal injuries are considered in construct planning, and the principles are discussed

Opioid use is associated with decreased quality of life in patients with Crohn′s disease

Background/Aims: Quality of life is an important consideration in the management of patients with Crohn′s disease. Previous studies suggest that Crohn′s disease patients using opioids may have decreased quality of life and increased risk of mortality. Our aim was to determine the association between health-related quality of life (HRQoL) and opioid use in patients with Crohn′s disease while controlling for disease severity. Patients and Methods: We conducted a cross-sectional study recruiting Crohn′s disease patients at our center. Disease activity was measured using the Harvey-Bradshaw Index (HBI), and HRQoL was measured using the Inflammatory Bowel Disease Questionnaire (IBDQ). Results: We enrolled 38 Crohn′s disease patients using opioids and 62 patients not using opioids. Patients using opioids had an increased duration of disease (median 18.5 vs. 9 years, P = 0.005), increased surgeries related to Crohn′s disease (median 3 vs. 0, P < 0.001), and increased prednisone use (29% vs. 11.3%, P = 0.03). Patients using opioids had increased disease activity (median HBI score 9.0 vs. 3.0, P < 0.001). Quality of life was lower in patients using opioids (mean IBDQ score 109.3 vs. 162.9, P < 0.001). This finding was significant when controlling for HBI scores, number of previous surgeries, and prednisone use (P = 0.003). Conclusions: Opioid use in Crohn′s disease patients appears to be associated with disease activity and severity. HRQoL is markedly decreased in patients using opioids and this association is significant even when controlling for variables reflecting disease severity. Our findings suggest that Crohn′s disease patients using opioids are likely to be significantly impacted by their disease