Menstrual Cycle Hormone Relaxin and ACL Injuries in Female Athletes: A Systematic Review.

Background: Female athletes are at increased risk for anterior cruciate ligament (ACL) injuries. The influence of hormonal variation on female ACL injury risk remains ill-defined. Recent data suggests that the collagen-degrading menstrual hormone relaxin may cyclically impact female ACL tissue quality. This review aims to identify any correlation between menstrual relaxin peaks and rates of female ACL injury. Methods: A systematic review was performed, utilizing the MEDLINE, EMBASE, and CINAHL databases. Included studies had to directly address relaxin/female ACL interactions. The primary outcome variable was relaxin proteolysis of the ACL, at cellular, tissue, joint, and whole-organism levels. The secondary outcome variable was any discussed method of moderating relaxin levels, and the clinical results if available. Results: AllThe numerous relaxin receptors on female ACLs upregulate local collagenolysis and suppress local collagen production. Peak serum relaxin concentrations (SRC) occur during menstrual cycle days 21-24; a time phase associated with greater risk of ACL injury. Oral contraceptives (OCPs) reduce SRC, with a potential ACLprotective effect. Conclusion: A reasonable correlative and plausible causative relationship exists between peak relaxin levels and increased risk of ACL injury in females, and further investigation is warranted. Level of Evidence: III.

Early Versus Delayed Surgery for Midshaft Clavicle Fractures: A Systematic Review.

Background: Orthopaedic surgeons debate the timing of and necessity for surgical intervention when treating displaced midshaft clavicle fractures (MCFs). This systematic review evaluates the available literature regarding functional outcomes, complication rates, nonunion, and reoperation rates between patients undergoing early versus delayed surgical management of MCFs. Methods: Search strategies were applied in PubMed (Medline), CINAHL (EBSCO), Embase (Elsevier), Sport Discus (EBSCO), and Cochrane Central Register of Controlled Trials (Wiley). Following an initial screening and full-text review, demographic and study outcome data was extracted for comparison between the early fixation and delayed fixation studies. Results: Twenty-one studies were identified for inclusion. This resulted in 1158 patients in the early group and 44 in the delayed. Demographics were similar between groups except for a higher percentage of males in the early group (81.6% vs. 61.4%) and longer time to surgery in the delayed group (4.6 days vs. 14.5 months). Disability of the arm, shoulder, and hand scores (3.6 vs. 13.0) and Constant-Murley scores (94.0 vs. 86.0) were better in the early group. Percentages of initial surgeries resulting in complication (33.8% vs. 63.6%), nonunion (1.2% vs. 11.4%), and nonroutine reoperation (15.8% vs. 34.1%) were higher in the delayed group. Conclusion: Outcomes of nonunion, reoperation, complications, DASH scores, and CM scores favor early surgery over delayed surgery for MCFs. However, given the small cohort of delayed patients who still achieved moderate outcomes, we recommend a shared decision-making style for treatment recommendations regarding individual patients with MCFs. Level of Evidence: II.

Stormwater biofilter response to high nitrogen loading under transient flow conditions: Ammonium and nitrate fates, and nitrous oxide emissions.

Nitrogen (N) in urban runoff is often treated with green infrastructure including biofilters. However, N fates across biofilters are insufficiently understood because prior studies emphasize low N loading under laboratory conditions, or use "steady-state" flow regimes over short time scales. Here, we tested field scale biofilter N fates during simulated storms delivering realistic transient flows with high N loading. Biofilter outflow ammonium (NH4+-N) was 60.7 to 92.3% lower than that of the inflow. Yet the characteristic times for nitrification (days to weeks) and denitrification (days) relative to N residence times (7 to 30 h) suggested low N transformation across the biofilters. Still, across 7 successive storms, total outflow nitrate (NO3--N) greatly exceeded (3100 to 3900%) inflow nitrate, a result only explainable by biofilter soil N nitrification occurring between storms. Archaeal, and bacterial amoA gene copies (2.1 × 105 to 1.2 × 106 gc g soil-1), nitrifier presence by16S rRNA gene sequencing, and outflow δ18O-NO3- values (-3.0 to 17.1 ‰) reinforced that nitrification was occurring. A ratio of δ18O-NO3- to δ15N-NO3- of 1.83 for soil eluates indicated additional processes: N assimilation, and N mineralization. Denitrification potential was suggested by enzyme activities and soil denitrifying gene copies (nirK + nirS: 3.0 × 106 to 1.8 × 107; nosZ: 5.0 × 105 to 2.2 × 106 gc g soil-1). However, nitrous oxide (N2O-N) emissions (13.5 to 84.3 µg N m - 2 h - 1) and N2O export (0.014 g N) were low, and soil nitrification enzyme activities (0.45 to 1.63 mg N kg soil-1day-1) exceeded those for denitrification (0.17 to 0.49 mg N kg soil-1 day-1). Taken together, chemical, bacterial, and isotopic metrics evidenced that storm inflow NH4+sorbs and, along with mineralized soil N, nitrifies during biofilter dry-down; little denitrification and associated N2O emissions ensue, and thus subsequent storms export copious NO3--N. As such, pulsed pass-through biofilters require redesign to promote plant assimilation and/or denitrification of mineralized and nitrified N, to minimize NO3--N generation and export.

The Incidence and Outcomes Following Treatment of Capsulolabral Adhesions in Hip Arthroscopy: A Systematic Review.

Background: To perform a systematic review to evaluate the incidence of capsulolabral adhesions following hip arthroscopy (HA) for femoroacetabular impingement (FAI); including risk factors and post-treatment outcomes. Methods: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we queried PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for English-language studies with minimum 6-month follow-up after primary or revision HA for FAI, which reported the incidence of capsulolabral adhesions. Potential adhesion risk factors, such as anchor type used and protocol for capsule closure, were assessed. Pre-operative and post-operative modified Harris Hip Score (mHHS) values were compared in studies that reported them. Results: Thirty-seven articles were included (24 primary HA; 13 revision HA). There were 6747 patients who underwent primary HA (6874 hips; 3005 female, 44%). The incidence of capsulolabral adhesions, confirmed surgically during revision HA, was low. Patients undergoing surgical treatment reported postoperative improvement per modified Harris Hip Scores. Data for 746 patients undergoing second revision HA (761 hips; 449 female, 60%), showed an incidence of adhesions greater than that of primary HA patients. Conclusion: While the incidence of symptomatic capsulolabral adhesions after primary hip arthroscopy is low; revision hip arthroscopy is strongly associated with adhesion development. Lysis of adhesions in primary hip arthroscopy patients reliably improved patient-reported outcomes. Level of Evidence: IV.

Sex Differences in Patient-Reported Outcomes Following Surgical Hip Preservation Interventions: A Systematic Review and Meta-Analysis.

Background: Female patients undergoing hip preservation surgery often have inferior patient-reported outcome scores (PROs), raising concerns about the clinical benefit of hip preservation surgery in women. Comparison of preoperative and postoperative PROs, and change in PROs, for female versus (vs.) male hip preservation patients was completed via systematic review. Methods: In accordance with PRISMA guidelines, the MEDLINE, Cochrane Central, and Em-base databases were searched. Level I-IV studies of patients undergoing surgical intervention for femoroacetabular impingement (FAI) and/or developmental dysplasia of the hip (DDH) with at least two years of postoperative follow-up were included. Sex-stratified PRO scores or outcome information had to be included. Results: We identified 32 hip preservation studies evaluating sex-related PRO differences, and/or providing sex-specific PRO data. The quantitative analysis of 24 studies (1843 patients) was stratified by DDH status. The modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL), and Hip Outcome Score-Sport-Specific subscale (HOS-SSS) were assessed. Patients undergoing surgery for FAI only were 52.1% female (n= 806/1546). As predicted, women had lower preoperative PRO scores, however, they had significantly greater improvements in HOS-ADL (20.14±4.41 vs. 26.00±0.35, p<0.05) and HOS-SSS (33.21± 0.71 vs. 38.33± 0.46, p<0.05) compared to males. Similar results were found in the DDH cohort of 330 patients (72.1% female): females had lower preoperative PRO scores, but significantly greater improvement of mHHS (22.68±0.45 vs. 10.60±1.46, p<0.01). Conclusion: The present review suggests that men undergoing surgery for FAI and/or DDH tend to have higher preoperative and postoperative PRO scores. However, it appears that women often have greater preoperative to postoperative improvement in PRO scores. This finding is strongest in surgical treatment of DDH. Level of Evidence: III.

Menstrual hormone-induced cyclic thumb CMC instability and degeneration in women: a systematic review.

BACKGROUND: Relaxin is a hormone which peaks during the luteal phase of the menstrual cycle, and a known collagenolytic promoter that has been shown to avidly bind tissues supporting the trapeziometacarpal (TMC) joint in women. We hypothesize a causal linkage between cyclic binding of relaxin to the supporting tissues of the female TMC joint; and to the earlier onset of more severe TMC osteoarthritis (OA) commonly seen in women. METHODS: A systematic literature review was performed per PRISMA guidelines, qualitatively and quantitatively assessing papers regarding relaxin-TMC joint stability interactions. The primary outcome variable was TMC joint degeneration/loss of function; the "late stage" consequences of relaxin-induced instability. The secondary outcome variable was presence of early signs of relaxin-induced instability; specifically asymptomatic TMC joint laxity in young women. RESULTS: In healthy young women, menstrual cycle relaxin peaks corresponded with asymptomatic TMC joint instability. Immunohistochemical studies of TMC arthroplasty patients showed avidly increased relaxin binding to supporting tissues around the TMC joint in women but not men. Demographic analysis of patients from the TMC arthroplasty studies show a predominantly female cohort, who were on average significantly younger than the male surgical patients. CONCLUSIONS: Each relaxin peak during the menstrual cycle can target receptors on the soft tissues supporting the TMC joint, including-critically-the main stabilizing ligament: the anterior oblique. The cyclic instability is typically asymptomatic for years after menarche, but causes cumulative chondral microtrauma. This likely causes the early-onset, high severity TMC joint OA clinically pervasive among female patients at orthopedic hand clinics. Further research is indicated to develop risk assessment strategies and potential interventional options before and after the onset of hormonal laxity-induced OA.

Highly variable removal of pathogens, antibiotic resistance genes, conventional fecal indicators and human-associated fecal source markers in a pilot-scale stormwater biofilter operated under realistic stormflow conditions.

Green stormwater infrastructure systems, such as biofilters, provide many water quality and other environmental benefits, but their ability to remove human pathogens and antibiotic resistance genes (ARGs) from stormwater runoff is not well documented. In this study, a field scale biofilter in Southern California (USA) was simultaneously evaluated for the breakthrough of a conservative tracer (bromide), conventional fecal indicators, bacterial and viral human-associated fecal source markers (HF183, crAssphage, and PMMoV), ARGs, and bacterial and viral pathogens. When challenged with a 50:50 mixture of untreated sewage and stormwater (to mimic highly contaminated storm flow) the biofilter significantly removed (p < 0.05) 14 of 17 microbial markers and ARGsin descending order of concentration reduction: ermB (2.5 log(base 10) reduction) > Salmonella (2.3) > adenovirus (1.9) > coliphage (1.5) > crAssphage (1.2) > E. coli (1.0) ∼ 16S rRNA genes (1.0) ∼ fecal coliform (1.0) ∼ intl1 (1.0) > Enterococcus (0.9) ∼ MRSA (0.9) ∼ sul1 (0.9) > PMMoV (0.7) > Entero1A (0.5). No significant removal was observed for GenBac3, Campylobacter, and HF183. From the bromide data, we infer that 0.5 log-units of attenuation can be attributed to the dilution of incoming stormwater with water stored in the biofilter; removal above this threshold is presumably associated with non-conservative processes, such as physicochemical filtration, die-off, and predation. Our study documents high variability (>100-fold) in the removal of different microbial contaminants and ARGs by a field-scale stormwater biofilter operated under transient flow and raises further questions about the utility of human-associated fecal source markers as surrogates for pathogen removal.

Do Relaxin Levels Impact Hip Injury Incidence in Women? A Scoping Review.

Purpose: The aim of this review is to assess the current evidence regarding the impact of relaxin on incidence of soft tissue hip injuries in women. Methods: A trained research librarian assisted with searches of PubMed, Embase, CINAHL, and SPORTDiscus, with a preset English language filter. The review was completed per the Joanna Briggs Institute (JBI) Manual for Evidence Synthesis methodology. Included studies required assessment of relaxin effects on musculoskeletal health, pelvic girdle stability, or hip joint structures in human subjects. Letters, texts, and opinion papers were excluded. Results: Our screen yielded 82 studies. Molecularly, relaxin activates matrix metalloproteinases (MMPs) including collagenases MMP-1/-13 and gelatinases MMP-2/-9 to loosen pelvic ligaments for parturition. However, relaxin receptors have also been detected in female periarticular tissues, such as the anterior cruciate ligament, which tears significantly more often during the menstrual cycle peak of relaxin. Recently, high concentrations of relaxin-activated MMP-9 receptors have been found on the acetabular labrum; their expression upregulated by estrogen. Conclusions: Menstrual cycle peaks of relaxin activate MMPs, which locally degrade collagen and gelatine. Women have relaxin receptors in multiple joints including the hip and knee, and increased relaxin correlates with increased musculoskeletal injuries. Relaxin has paracrine effects in the female pelvis on ligaments adjacent to hip structures, such as acetabular labral cells which express high levels of relaxin-targeted MMPs. Therefore, it is imperative to investigate the effect of relaxin on the hip to determine if increased levels of relaxin are associated with an increased risk of acetabular labral tears.

PROMIS Versus Legacy Patient-Reported Outcome Measures for Sports Medicine Patients Undergoing Arthroscopic Knee, Shoulder, and Hip Interventions: A Systematic Review.

Background: The Patient-Reported Outcomes Measurement Information System (PROMIS®) was designed to monitor the global wellbeing of patients, with the Physical Function Computer-Adaptive Test (PF-CAT) component focused specifically on functional outcome. PROMIS aims for increased item-bank accuracy, lower administrative burden, and decreased floor and ceiling effects compared to legacy patient-reported outcome measures (PROMs). Our primary research outcomes focused on sports medicine surgical populations, which may skew younger or have wide-ranging functional statuses. Specifically, for this population, we questioned if PROMIS PF-CAT was equal to legacy PROMs in (1) construct validity and (2) convergent/divergent validities; and superior to legacy PROMs with respect to (3) survey burden and (4) floor and ceiling effects. Methods: Searches were performed in April 2019 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, utilizing PubMed, Cochrane Central, and Embase databases for Level I-III evidence. This resulted in 541 records, yielding 12 studies for inclusion. PROM data was available for patients undergoing arthroscopic orthopaedic procedures of the knee, shoulder, and hip. Measures of construct validity, convergent/divergent validity, survey burden, and floor/ceiling effects were evaluated for PROMIS PF-CAT versus legacy PROMs. Results: PROMIS PF-CAT demonstrated excellent or excellent-good correlation with legacy PROMS for physical function and quality of life for patients undergoing arthroscopic interventions of the knee, shoulder, and hip. Compared to legacy PROM instruments, PROMIS PF-CAT demonstrated the lowest overall survey burden and had the lowest overall number of floor or ceiling effects across participants. Conclusion: PROMIS PF-CAT is an accurate, efficient evaluation tool for sports medicine surgical patients. PROMIS PF-CAT strongly correlates with legacy physical function PROMs while having a lower test burden and less incidence of floor and ceiling effects. PROMIS PF-CAT may be an optimal alternative for traditional physical function PROMs in sports medicine patients undergoing arthroscopic procedures. Further studies are required to extend the generalizability of these findings to patients during postoperative timepoints after shoulder and hip interventionsLevel of Evidence: III.

Limited Bacterial Removal in Full-Scale Stormwater Biofilters as Evidenced by Community Sequencing Analysis.

In urban areas, untreated stormwater runoff can pollute downstream surface waters. To intercept and treat runoff, low-impact or "green infrastructure" approaches such as using biofilters are adopted. Yet, actual biofilter pollutant removal is poorly understood; removal is often studied in laboratory columns, with variable removal of viable and culturable microbial cell numbers including pathogens. Here, to assess bacterial pollutant removal in full-scale planted biofilters, stormwater was applied, unspiked or spiked with untreated sewage, in simulated storm events under transient flow conditions, during which biofilter influents versus effluents were compared. Based on microbial biomass, sequences of bacterial community genes encoding 16S rRNA, and gene copies of the human fecal marker HF183 and of the Enterococcus spp. marker Entero1A, removal of bacterial pollutants in biofilters was limited. Dominant bacterial taxa were similar for influent versus effluent aqueous samples within each inflow treatment of either spiked or unspiked stormwater. Bacterial pollutants in soil were gradually washed out, albeit incompletely, during simulated storm flushing events. In post-storm biofilter soil cores, retained influent bacteria were concentrated in the top layers (0-10 cm), indicating that the removal of bacterial pollutants was spatially limited to surface soils. To the extent that plant-associated processes are responsible for this spatial pattern, treatment performance might be enhanced by biofilter designs that maximize influent contact with the rhizosphere.

Abnormal Femoral Anteversion Is Associated With the Development of Hip Osteoarthritis: A Systematic Review and Meta-Analysis.

PURPOSE: To perform a systematic review and meta-analysis of literature and to evaluate the relationship between abnormal femoral version and the development of hip osteoarthritis (OA). METHODS: A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, evaluating Level I and II studies. Included studies had to provide granular femoral version (FV) information. The severity of OA was ranked on the Kellgren-Lawrence (KL) scale. Excel version 1808 (Microsoft, Redmond, WA) was used to perform a student t test statistical analyses. RESULTS: Our review identified 19 qualifying studies-5 Level I and 14 Level II with 1,756 patients. Patients with FV above normal range (>14°) had greater KL scores than patients with normal range FV (mean ± standard deviation; 3.37 ± 1.44 vs 2.05 ± 1.72, P < .05). Analysis of KL scores in patients with FV >24° (>1 standard deviation) versus patients with FV >14° but <24° also demonstrated a positive correlation between increasing FV and KL (4.00 ± 1.96 vs 2.34 ± 0). This was significant independent of the presence or absence of developmental dysplasia of the hip. Retroverted hips (FV<10°) in the present study showed variable OA results upon analysis. CONCLUSIONS: The present review suggests that elevated FV may be a risk factor for more severe hip OA with or without the presence of concurrent dysplasia of the hip. The relative amount of increased anteversion appears positively correlated with severity of OA. Although femoral retroversion may impact hip mechanics, in this review it does not appear to strongly correlate with the development of OA. LEVEL OF EVIDENCE: II: systematic review of Level I and II studies.

Perioperative and Postoperative Factors Influence Quadriceps Atrophy and Strength After ACL Reconstruction: A Systematic Review.

BACKGROUND: Quadriceps dysfunction after anterior cruciate ligament (ACL) reconstruction is common and may affect return to sport due to resulting muscle atrophy and muscle weakness. PURPOSE: To systematically review the available literature regarding the impact of perioperative and postoperative interventions on quadriceps atrophy and loss of strength after ACL reconstruction. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: A systematic review was performed in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, CINAHL, Cochrane Central, and Embase. The quality of evidence was evaluated using the Modified Coleman Methodology Score to determine consensus scores. Eligible level 1 or level 2 studies included interventions of perioperative nerve block, intraoperative tourniquet use, postoperative nutritional supplementation, and postoperative blood flow restriction training. Additionally, the included studies quantified postoperative quadriceps measurements such as thigh circumference, quadriceps cross-sectional area (CSA), isokinetic quadriceps strength, and/or quadriceps electromyographic (EMG) testing. RESULTS: In total, 15 studies met stated inclusion and exclusion criteria with the following intervention types: perioperative nerve block (n = 4), intraoperative tourniquet use (n = 5), postoperative nutritional supplementation (n = 3), and postoperative blood flow restriction (n = 3). Intraoperative tourniquet use resulted in decreased thigh circumference and detrimental EMG changes in quadriceps function in 3 of the 5 included studies. Perioperative femoral nerve blocks were associated with transient decreases in postoperative quadriceps strength, persisting up to 6 weeks after surgery, in 2 of the 4 studies. Postoperative blood flow restriction training augmented quadriceps size and function after ACL reconstruction in 2 of 3 studies. Postoperative nutritional supplementation was associated with increased quadriceps volume and strength in 1 of the 3 studies examined. CONCLUSION: The peri- and postoperative factors reviewed here may influence quadriceps atrophy and strength after ACL reconstruction. Our results tentatively indicated that blood flow restriction training may be beneficial to the quadriceps after ACL reconstruction and that intraoperative tourniquet use and nerve block administration may be detrimental; however, the strongest finding was that all of these interventions would benefit from further level 1 and 2 evidence studies, including multicenter, randomized controlled trials with extended follow-up, to definitively determine their impact on return to activity.

Endoscopic Gluteus Medius Repair With an ITB-Sparing Versus ITB-Splitting Approach: A Systematic Review and Meta-analysis.

BACKGROUND: During hip endoscopy, the iliotibial band (ITB) can be split or preserved to access the peritrochanteric workspace. To our knowledge, no comparative studies have been performed to analyze patient-reported outcomes (PROs) and surgical failure rates (gluteus medius retear and/or revision surgery rates) for ITB-sparing versus ITB-splitting approaches in endoscopic gluteus medius repairs. PURPOSE: To perform a systematic review and meta-analysis of the literature to evaluate PROs and failure rates of patients undergoing ITB-sparing versus ITB-splitting repairs of the gluteus medius. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was performed by following PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines and using the PubMed, Cochrane CENTRAL, and Embase databases. The quality of evidence was evaluated using the modified Coleman Methodology Score. Level 1-4 studies were evaluated for endoscopic abductor repair techniques on all types of gluteus medius tears. Given the small number of studies and varying population sizes, all quantitative data were adjusted for study population size. RESULTS: A total of 13 studies met our inclusion criteria, while more granular data, including ITB approach, were available for 8 studies. Because of the paucity of literature on the subject, all included studies were of lower quality per the modified Coleman Methodology Score. The visual analog scale for pain, the modified Harris Hip Score (mHHS), and the surgical failure rates were compared between approaches. Patients who underwent ITB splitting had a significantly greater change in mHHS (45.5 ± 4.6 vs 27.3 ± 6.5; P < .001) and lower surgical failure rates (3.67 ± 2.33 vs 4.75 ± 2.54; P = .04). There was no significant difference in change in visual analog scale for splitting versus sparing (4.26 ± 0.41 vs 4.39 ± 0.14; P = .96). The results may have been biased by between-group differences, such as patients who undergo ITB sparing being significantly younger. CONCLUSION: Endoscopic gluteus medius repair is a reliable procedure to improve pain and function in appropriately selected patients. This study highlighted the lack of high-quality literature available regarding ITB approach. However, the evidence to date has suggested that ITB approach may influence hip-specific PROs. Splitting the ITB during abductor repair may be associated with a greater improvement in mHHS and lower surgical failure rates. Further prospective comparative studies are warranted to evaluate the effect of ITB approach.

Predictive Power of Clean Bed Filtration Theory for Fecal Indicator Bacteria Removal in Stormwater Biofilters.

Green infrastructure (also referred to as low impact development, or LID) has the potential to transform urban stormwater runoff from an environmental threat to a valuable water resource. In this paper we focus on the removal of fecal indicator bacteria (FIB, a pollutant responsible for runoff-associated inland and coastal beach closures) in stormwater biofilters (a common type of green infrastructure). Drawing on a combination of previously published and new laboratory studies of FIB removal in biofilters, we find that 66% of the variance in FIB removal rates can be explained by clean bed filtration theory (CBFT, 31%), antecedent dry period (14%), study effect (8%), biofilter age (7%), and the presence or absence of shrubs (6%). Our analysis suggests that, with the exception of shrubs, plants affect FIB removal indirectly by changing the infiltration rate, not directly by changing the FIB removal mechanisms or altering filtration rates in ways not already accounted for by CBFT. The analysis presented here represents a significant step forward in our understanding of how physicochemical theories (such as CBFT) can be melded with hydrology, engineering design, and ecology to improve the water quality benefits of green infrastructure.