Linking catchment structural units (CSUs) with water quality: Implications for ambient monitoring network design and data interpretation.

Climate induced changes in runoff regimes and ongoing anthropogenic modification of land use and land cover (LULC) are shifting ambient water quality signals worldwide. Modulation of these signals by the physical catchment structure over different scales adds complexity to interpreting and analyzing measured data. Further bias may be introduced where monitoring networks are not representative of the structure of catchments in a given region. Here, we present a new environmental regionalization method to assess the representativeness of water quality monitoring (WQM) networks and to identify key structural drivers linked to water quality signals. Unique numerical codes were generated at the pixel level to provide wall-to-wall coverage of key Catchment Structural Units (CSUs) based on LULC, surficial geology, wetlands and slope. CSU codes were generated for all tributary (AT) catchments >20 km2 in Southern Alberta (n = 289), Canada, to determine the representativeness of an existing WQM network (54 tributary catchments) and to assess the explanatory power of CSUs with respect to water quality signals. Cluster analysis (CA) and multi-dimensional scaling (MDS) on the percent area of CSUs in the AT catchments identified six primary structural clusters in Southern Alberta. A clear gradient in catchment structure was evident progressing downstream from the Rocky Mountain headwaters through the foothills and prairie/plains region. Montane and grassland regions were found to be potentially under-represented by the current WQM program whereas catchments dominated by agriculture were likely over-represented. The disproportionate impact of specific CSU combinations on water quality was illustrated where the CA and MDS analyses indicated that even small percentages of urban areas and badland type topography results in elevated concentrations of total recoverable metals, nutrients and major ions. The application of the CSU approach in Southern Alberta demonstrates its value as an alternative method to assess and/or redesign existing WQM networks and to link water quality data to the structural composition of catchments. The general availability of the required data to generate CSUs provides universal potential for the approach to help assess other WQM programs and to contextualize data records. Applying the CSU approach when developing new ambient WQM networks can also help reduce the potential of over-monitoring similarly structured catchments as well as ensuring that all structural classes are represented by the data being generated.

Comprehensive Shoulder US Examination: A Standardized Approach with Multimodality Correlation for Common Shoulder Disease.

Shoulder pain is one of the most common musculoskeletal conditions encountered in primary care and specialty orthopedic clinic settings. Although magnetic resonance (MR) imaging is typically the modality of choice for evaluating the soft-tissue structures of the shoulder, ultrasonography (US) is becoming an important complementary imaging tool in the evaluation of superficial soft-tissue structures such as the rotator cuff, subacromial-subdeltoid bursa, and biceps tendon. The advantages of US driving its recent increased use include low cost, accessibility, and capability for real-time high-resolution imaging that enables dynamic assessment and needle guidance. As more radiologists are considering incorporating shoulder US into their practices, the development of a standardized approach to performing shoulder US should be a priority to facilitate the delivery of high-quality patient care. Familiarity with and comfort in performing a standardized shoulder US examination, as well as knowledge of the types of anomalies that can be evaluated well with US, will enhance the expertise of those working in musculoskeletal radiology practices and add value in the form of increased patient and health care provider satisfaction. This review describes the utility and benefits of shoulder US as a tool that complements MR imaging in the assessment of shoulder pain. A standardized approach to the shoulder US examination is also described, with a review of the basic technique of this examination, normal anatomy of the shoulder, common indications for shoulder US, and characteristic US findings of common shoulder diseases-with select MR imaging and arthroscopic correlation. Online supplemental material is available for this article. ©RSNA, 2016.

Sublabral clefts and recesses in the anterior, inferior, and posterior glenoid labrum at MR arthrography.

PURPOSE: To determine the prevalence of a normal variant cleft/recess at the labral-chondral junction in the anterior, inferior, and posterior portions of the shoulder joint. MATERIALS AND METHODS: One hundred and three consecutive patients (106 shoulders) who had a direct MR arthrogram followed by arthroscopic surgery were enrolled in this IRB-approved study. Scans were carried out on a 1.5-T scanner with an eight-channel shoulder coil. The glenoid rim was divided into eight segments and the labrum in all but the superior and anterosuperior segments was evaluated by two radiologists for the presence of contrast between the labrum and articular cartilage. We measured the depth of any cleft/recess and correlated the MR findings with surgical results. Generalized estimating equation models were used to correlate patient age and gender with the presence and depth of a cleft/recess, and Cohen's kappa values were calculated for interobserver variability. RESULTS: For segments that were normal at surgery, a cleft/recess was present within a segment on MR arthrogram images in as few as 7 % of patients (within the posteroinferior segment by observer 1), and in up to 61 % of patients (within the posterosuperior segment by observer 1). 55-83 % of these were only 1 mm deep. A 2- to 3-mm recess was seen within 0-37 % of the labral segments, most commonly in the anterior, anteroinferior, and posterosuperior segments. Age and gender did not correlate with the presence of a cleft/recess, although there was an association between males and a 2- to 3-mm deep recess (p = 0.03). The interobserver variability for each segment ranged between 0.15 and 0.49, indicating slight to moderate agreement. CONCLUSION: One-mm labral-chondral clefts are not uncommon throughout the labrum. A 2- to 3-mm deep smooth, medially curved recess in the anterior, anteroinferior or posterosuperior labrum can rarely be seen, typically as a continuation of a superior recess or anterosuperior labral variant.

Severe western Canadian wildfire affects water quality even at large basin scales.

Wildfires can have severe and lasting impacts on the water quality of aquatic ecosystems. However, our understanding of these impacts is founded primarily from studies of small watersheds with well-connected runoff regimes. Despite the predominance of large, low-relief rivers across the fire-prone Boreal forest, it is unclear to what extent and duration wildfire-related material (e.g., ash) can be observed within these systems that typically buffer upstream disturbance signals. Following the devastating 2016 Fort McMurray wildfire in western Canada, we initiated a multi-faceted water quality monitoring program that suggested brief (hours to days) wildfire signatures could be detected in several large river systems, particularly following rainfall events greater than 10 mm. Continuous monitoring of flow and water quality showed distinct, precipitation-associated signatures of ash transport in rivers draining expansive (800-100,000 km2) and partially-burned (<1-22 percent burned) watersheds, which were not evident in nearby unburned regions. Yields of suspended sediment, nutrients (nitrogen, phosphorus) and metals (lead, others) from impacted rivers were 1.2-10 times greater than from those draining unburned regions. Post-fire suspended sediment concentrations in impacted rivers were often larger than pre-fire 95% prediction intervals based on several years of water sampling. These multiple lines of evidence indicate that low-relief landscapes can mobilize wildfire-related material to rivers similarly, though less-intensively and over shorter durations, than headwater regions. We propose that uneven mixing of heavily-impacted tributaries with high-order rivers may partially explain detection of wildfire signals in these large systems that may impact downstream water users.

Joint Design with Providers of Clinical Decision Support for Value-Based Advanced Shoulder Imaging.

BACKGROUND: Provider orders for inappropriate advanced imaging, while rarely altering patient management, contribute enough to the strain on available health care resources, and therefore the United States Congress established the Appropriate Use Criteria Program. OBJECTIVES: To examine whether co-designing clinical decision support (CDS) with referring providers will reduce barriers to adoption and facilitate more appropriate shoulder ultrasound (US) over magnetic resonance imaging (MRI) in diagnosing Veteran shoulder pain, given similar efficacies and only 5% MRI follow-up rate after shoulder US. METHODS: We used a theory-driven, convergent parallel mixed-methods approach to prospectively (1) determine medical providers' reasons for selecting MRI over US in diagnosing shoulder pain and identify barriers to ordering US, (2) co-design CDS, informed by provider interviews, to prompt appropriate US use, and (3) assess CDS impact on shoulder imaging use. CDS effectiveness in guiding appropriate shoulder imaging was evaluated through monthly monitoring of ordering data at our quaternary care Veterans Hospital. Key outcome measures were appropriate MRI/US use rates and transition to ordering US by both musculoskeletal specialist and generalist providers. We assessed differences in ordering using a generalized estimating equations logistic regression model. We compared continuous measures using mixed effects analysis of variance with log-transformed data. RESULTS: During December 2016 to March 2018, 569 (395 MRI, 174 US) shoulder advanced imaging examinations were ordered by 111 providers. CDS "co-designed" in collaboration with providers increased US from 17% (58/335) to 50% (116/234) of all orders (p < 0.001), with concomitant decrease in MRI. Ordering appropriateness more than doubled from 31% (105/335) to 67% (157/234) following CDS (p < 0.001). Interviews confirmed that generalist providers want help in appropriately ordering advanced imaging. CONCLUSION: Partnering with medical providers to co-design CDS reduced barriers and prompted appropriate transition to US from MRI for shoulder pain diagnosis, promoting evidence-based practice. This approach can inform the development and implementation of other forms of CDS.

Arthroscopically assisted mini-open rotator cuff repair.

PURPOSE: To review the results of arthroscopically assisted mini-open rotator cuff repair. TYPE OF STUDY: Retrospective clinical review. METHODS: From 1990 to 1994, 67 patients (69 shoulders) had a rotator cuff repair for a full-thickness tear; 63 of these patients had an arthroscopically assisted mini-open rotator cuff repair. Of these, 22 were lost to follow-up; thus, 41 patients were retrospectively reviewed for this study. The average patient age was 51 years and the average follow-up was 36 months. UCLA scores incorporating preoperative and postoperative pain, function, strength, and range of motion data were used to analyze the results. RESULTS: At follow-up, 38 patients (93%) were rated as excellent or good, 3 patients (7%) were rated as fair, and none was rated as poor. All patients showed improvement in pain and function after surgery and all of the patients were satisfied with the procedure. The average UCLA score was 32.3. There was a small but significant (P <.0001) difference between UCLA scores of Workers' Compensation patients (UCLA score, 29; n = 11) versus noncompensation patients (UCLA score, 33; n = 30). In addition, the return-to-work interval was prolonged in the Workers' Compensation cases. There were no significant differences in UCLA scores on the basis of tear size (P <.4286) or patient age (P <.1131). CONCLUSIONS: Our data suggest that the arthroscopically assisted mini-open technique for rotator cuff repair is an excellent approach for repair of a torn rotator cuff.

Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit.

PURPOSE: To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images. MATERIALS AND METHODS: This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance. RESULTS: The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65 degrees (SD 27 degrees) for the controls and 94 degrees (SD 38 degrees) for the athletes (P = 0.002). CONCLUSIONS: Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement.

Operative treatment of the painful sternoclavicular joint: a new technique using interpositional arthroplasty.

This study presents the results of a new surgical technique, resection of the medial end of the clavicle and interposition of the sternal head of the sternocleidomastoid muscle, that was used for the treatment of 17 painful sternoclavicular (SC) joints, 14 of which were available for review. The etiology of the pain was primary or posttraumatic degenerative arthritis in 10, osteitis condensans in 2, and SC joint infection in 2. The results of surgery, evaluated with the Rockwood SC joint rating scale and examination of the patients, were determined at a mean follow-up of 46 months. Results were excellent in 4 shoulders, good in 6, fair in 3, and poor in 1. All of the fair and poor results occurred in workers' compensation patients. Interposition arthroplasty performed in conjunction with resection of the medial clavicle proved to be a safe and effective method of treatment for the painful, degenerative or septic SC joint.

Overuse Injuries of the Elbow.

In brief Sports-related overuse injuries brief of the elbow occur most often in people involved in throwing and racket sports. Common injuries include medial and lateral epicondylitis, radial tunnel syndrome, ulnar nerve entrapment, triceps and biceps tendinitis, and conditions related to valgus extension overload: ulnar collateral ligament tears, lateral compartment osteochondral injuries, and posterior olecranon impingement. Accurate diagnosis requires an understanding of elbow anatomy and a careful physical examination. Most of these injuries respond to activity modification, nonsteroidal anti-inflammatory drugs, and a directed rehabilitation program. Surgical intervention, however, is occasionally necessary.

Sublabral foramen and buford complex: inferior extent of the unattached or absent labrum in 50 patients.

PURPOSE: To determine the inferiormost extent of the anterosuperior labral variants on conventional transverse MR images. MATERIALS AND METHODS: We reviewed transverse MR images in 50 consecutive patients with a sublabral foramen or Buford complex at arthroscopy. Images were randomly mixed with those of 58 patients with either a normal labrum (n = 20) or an anterior labral tear (n = 38) at arthroscopy. MR imaging was fat suppressed fast spin echo intermediate or T2 weighted (repetition time msec/effective echo time msec, 1,800-3,000/30-102). Two radiologists evaluated by means of consensus the anterior labrum while blinded to patient history and arthroscopic results. Transverse images obtained through the glenoid fossa were totalled to determine the midpoint. Sensitivity, specificity, and accuracy of MR for depicting a sublabral foramen or Buford complex were calculated along with 95% CIs, by using surgical findings as the reference standard. RESULTS: The sensitivity of MR for diagnosing a sublabral foramen or Buford complex was 0.94 (47 of 50 patients, 95% CI: 0.87, 1.00), specificity was 0.80 (16 of 20 patients, 95% CI: 0.62, 0.97), and accuracy was 0.90 (63 of 70 patients, 95% CI: 0.82, 0.97). The anterior labrum was abnormal on the first transverse section inferior to the midpoint in nine (18%) patients. The labrum was also abnormal on the second section below the midpoint in three (6%) patients. Because of the anterior tilt of the scapula, the midpoint was near the anterior glenoid notch at about the position between 2- and 3-o'clock. CONCLUSION: The labrum may be unattached or absent on the first two transverse images obtained below the midpoint.