Postfire reproduction of a serotinous conifer, the giant sequoia, in the Nelder Grove, California.

The giant sequoia, a serotinous conifer naturally occurring in mixed-conifer forests of the southern and central Sierra Nevada, California, USA, is the world's largest tree species. Giant sequoia reproduction has been severely lacking over the past century, due to fire exclusion, creating a significant conservation threat. Previous research on postfire sequoia reproduction in high-severity fire areas, relative to low- and moderate-severity areas, is limited. At 6 years postfire, we investigated giant sequoia reproduction in a high-severity fire area, and nearby low-/mixed-severity fire areas, in the Nelder Grove, which burned in 2017 in the Railroad fire. Postfire giant sequoia reproduction was positively correlated with fire severity in terms of density, height (growth), and proportion (relative to other conifer species), and sequoia seedling/sapling density was positively correlated with percent shrub cover. There was no correlation between distance to live sequoia seed source and density of sequoia reproduction. More research is needed in other mixed-severity fire areas, with larger high-severity fire patches, to determine whether a similar postfire response occurs elsewhere.

Return to Golf After Hip Arthroscopy: A Systematic Review of the Literature.

CONTEXT: Patients experiencing pain from femoral acetabular impingement and considering hip arthroscopy may be concerned about their timeline to resume activities they enjoy, such as golf. OBJECTIVE: The purpose of this study was to review current literature on return-to-play data after hip arthroscopy and to provide clinicians with data to set proper expectations with patients. DATA SOURCES: The following terms were used to search PubMed and Embase electronic databases on October 18, 2023: hip, arthroscopy, arthroscopic, golf. STUDY SELECTION: Studies were included if they were in the English language, of Level 1 to 4 evidence, and contained data specific to golfers undergoing hip arthroscopy. Studies were excluded if they did not designate participants as golfers or did not specify return-to-play data. Editorials, case reports, and review articles were excluded. Screening was completed by 2 authors in a blind and duplicate manner. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level II. DATA EXTRACTION: The following datapoints were extracted from each study: hip pathology and arthroscopic procedure data; number of players returning to golf and time from surgery to return; outcome score(s); and rehabilitation details. Descriptive statistics were calculated using Comprehensive Meta-Analysis software. RESULTS: The search returned 400 studies, of which 4 were included for analysis. Of these 4 studies, 2 specified return-to-play time. Of 95 golfers, 90 (94.7%) returned to golf successfully after arthroscopic hip surgery. Subjective and objective outcome scores improved postoperatively, including an increased average drive distance. CONCLUSION: Return to golf after hip arthroscopy is highly probable, with approximately 95% of patients throughout literature returning to play. A mean return time of 4.7 months for professional golfers and 7.2 months for amateurs, alongside improved subjective outcomes and performance metrics postsurgery, suggest patients can expect a relatively quick return to the course with similar or improved performance.

Education Research in Orthopaedic Surgery: A 6-Year Analysis.

With the ever-changing dynamics of surgical training, it is essential for the content of educational research to evolve simultaneously. This study aimed to assess the current state of scholarly work in orthopaedic training education and to identify particular educational topics that are trending in the literature. Methods: A PubMed search string was used to identify literature on orthopaedic surgery education from 2016 to 2021. Publications on orthopaedic surgery education were divided into 8 education-based categories: (1) operative training and simulation, (2) curriculum and career development, (3) diversity, (4) wellness and burnout, (5) program evaluation and match data, (6) trainee assessments, (7) social media, and (8) other. Univariate analysis and linear regression were used to determine trends. Results: A total of 383 orthopaedic surgery education publications met inclusion criteria. Orthopaedic surgery education publications accounted for 0.47% of the total publications from all 54 journals. Fifteen journals provided 85% of all orthopaedic education publications (N = 325). The Journal of Bone and Joint Surgery produced the most orthopaedic surgery education publications (76, 20%), followed by the Journal of Surgical Education (62, 16%) and the Journal of the American Academy of Orthopaedic Surgeons (58, 15%). Publications on curriculum and career development were the most common (21.9%). The following most frequent topics were program evaluation and match data (20.9%) and operative training and simulation (18%), respectively. Over the study period, the total amount of orthopaedic surgery education articles increased significantly (R2 = 0.86, p = 0.008). Articles included all levels of training, with resident education accounting for the majority, with 269 articles (70.2%). Conclusion: Recent trends in orthopaedic literature indicate an increased emphasis on education as the number of publications has increased, but are still sparse in orthopaedic literature. As the field of orthopaedics continues to advance, we recommend that academic institutions and organizations continue to evaluate and promote evidence-based educational research to ensure that orthopaedic education meets the ever-increasing demands that residents and practicing surgeons will face in the present and future. Level of Evidence: III.

Harms Reporting Is Inadequate in Systematic Reviews Regarding Hip Arthroscopy.

Purpose: To investigate the quality of harms reporting in systematic reviews (SRs) regarding hip arthroscopy in the current literature. Methods: In May 2022, an extensive search of 4 major databases was performed identifying SRs regarding hip arthroscopy: MEDLINE (PubMed and Ovid), EMBASE, Epistemonikos, and Cochrane Database of Systematic Reviews. A cross-sectional analysis was conducted, in which investigators performed screening and data extraction of the included studies in a masked, duplicate fashion. AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews-2) was used to assess the methodologic quality and bias of the included studies. The corrected covered area was calculated for SR dyads. Results: A total of 82 SRs were included in our study for data extraction. Of these SRs, 37 reported under 50% of the harms criteria (37 of 82, 45.1%) and 9 did not report harms at all (9 of 82, 10.9%). A significant relation was found between completeness of harms reporting and overall AMSTAR appraisal (P = .0261), as well as whether a harm was listed as a primary or secondary outcome (P = .0001). Eight SR dyads had corrected covered areas of 50% or greater and were compared for shared harms reported. Conclusions: In this study, we found inadequate harms reporting in most SRs concerning hip arthroscopy. Clinical Relevance: With the magnitude of hip arthroscopic procedures being performed, adequate reporting of harms-related information in the research surrounding this treatment is essential in assessing the efficacy of the treatment. This study provides data in relation to harms reporting in SRs regarding hip arthroscopy.

Assessment of Spin in the Abstracts of Systematic Reviews and Meta-analyses on Platelet-Rich Plasma Treatment in Orthopaedics: A Cross-sectional Analysis.

Background: Systematic reviews on the use of platelet-rich plasma (PRP) in orthopaedic surgery are abundant in current published literature. However, a beautification of results (referred to as spin) has been noted in abstracts across various aspects of medicine. Purpose: To determine the prevalence of spin in systematic reviews of PRP-related orthopaedic surgery abstracts. Study Design: Cross-sectional study. Methods: Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Murad and Wang guidelines, we conducted a search in Medline, Embase, and the Cochrane Database for reviews on PRP-related orthopaedic surgery. The search included studies published from inception until June 30, 2021. Included were systematic reviews written in English that involved the use of PRP in the treatment of orthopaedic injuries in human participants. The abstracts of the included reviews were evaluated for the top 9 types of spin as described by Yavchitz et al in 2016. We determined the relationship between spin and study characteristics using odds ratios. Results: Of an initial 1560 studies, 176 were included. We found that 50 studies (28.4%) contained at least 1 form of spin. The 2 most common forms of spin found in our sample were type 5 ("Conclusion claims the beneficial effect of treatment despite high risk of bias"; n = 27 [15.3%]) and type 3 ("Selective reporting or overemphasis of efficacy in outcomes favoring beneficial effect of intervention"; n = 18 [10.2%]). No statistical significance was found between study characteristics and the presence of spin. Conclusion: Spin was present in 28% of the systematic reviews that covered PRP-related orthopaedic treatments. Spin was not associated with general study characteristics, including adherence to PRISMA guidelines or funding. Journals and authors should be aware of spin in articles and avoid its usage.

No evidence of canopy-scale leaf thermoregulation to cool leaves below air temperature across a range of forest ecosystems.

Understanding and predicting the relationship between leaf temperature (Tleaf) and air temperature (Tair) is essential for projecting responses to a warming climate, as studies suggest that many forests are near thermal thresholds for carbon uptake. Based on leaf measurements, the limited leaf homeothermy hypothesis argues that daytime Tleaf is maintained near photosynthetic temperature optima and below damaging temperature thresholds. Specifically, leaves should cool below Tair at higher temperatures (i.e., > ∼25-30°C) leading to slopes <1 in Tleaf/Tair relationships and substantial carbon uptake when leaves are cooler than air. This hypothesis implies that climate warming will be mitigated by a compensatory leaf cooling response. A key uncertainty is understanding whether such thermoregulatory behavior occurs in natural forest canopies. We present an unprecedented set of growing season canopy-level leaf temperature (Tcan) data measured with thermal imaging at multiple well-instrumented forest sites in North and Central America. Our data do not support the limited homeothermy hypothesis: canopy leaves are warmer than air during most of the day and only cool below air in mid to late afternoon, leading to Tcan/Tair slopes >1 and hysteretic behavior. We find that the majority of ecosystem photosynthesis occurs when canopy leaves are warmer than air. Using energy balance and physiological modeling, we show that key leaf traits influence leaf-air coupling and ultimately the Tcan/Tair relationship. Canopy structure also plays an important role in Tcan dynamics. Future climate warming is likely to lead to even greater Tcan, with attendant impacts on forest carbon cycling and mortality risk.

Harms-related data are poorly reported among randomized controlled trials underpinning the American Academy of Orthopaedic Surgeons clinical practice guideline recommendations for rotator cuff injuries.

BACKGROUND: Results produced from randomized controlled trials (RCTs) help guide clinical decision making and health policy. Therefore, it is essential that RCT outcomes- including harms (eg, adverse events)-are adequately reported such that clinicians, patients, and policy makers are equipped with all necessary information to complete risk-benefit assessment of the RCT's intervention. Here, we evaluated the quality of reporting of harms (eg, adverse events) in RCTs cited as supporting evidence for recommendations in the American Academy of Orthopaedic Surgeons (AAOS) Management of Rotator Cuff Injuries clinical practice guidelines (CPGs) using the Consolidated Standards of Reporting Trials (CONSORT) Extension for Harms Checklist. METHODS: To quantify adherence to CONSORT Extension for Harms items, each RCT was screened for pertinent information satisfying each checklist item. Screening of CPG reference sections for RCTs underpinning CPG recommendations, as well as data extraction from each of the included RCTs, was performed in a blind and duplicate manner. Descriptive statistics-including frequencies, percentages, and 95% confidence intervals-were used to summarize overall percent adherence to checklist items. A linear regression model assessed the relationship of CONSORT Harms reporting over time. RESULTS: Ninety-nine RCTs were included in our final sample. Fifty-seven RCTs (of 99; 57.6%) were conducted at a single center. Common funding sources included private (nonindustry) (17/99; 17.2%), private (industry) (8/99; 8.1%), and public (7/99; 7.1%) sources. Sample size for each trial most often consisted of <50 participants (29/99; 29.3%) or 51-100 participants (50/99; 50.5%). The average number of CONSORT Extension for Harms items adequately reported across all included RCTs was 5.7 (of 18; 31.7%). None of the included trials reported all 18 items. Twenty-six RCTs (of 99; 26.3%) adequately reported ≥50% of eligible checklist items. Fifty-nine RCTs (of 99; 59.6%) adequately reported ≤33% of eligible checklist items. Items with ≥50% adherence included item 2, item 7a, and item 8a. Items with ≤20% adherence included item 3b, item 4d, and item 5. Results from our linear regression demonstrated a slight, yet nonsignificant, improvement in adherence to the Harms Extension over time (R2 = 0.009; P = .407). CONCLUSIONS: Our results illustrate the poor state of harms reporting within RCTs cited as supporting evidence for the AAOS Management of Rotator Cuff Injuries CPG. Efforts to address these gaps in reporting are warranted, as complete knowledge of potential harms is critical to patients, clinicians, and health policy makers when determining best practice decisions in orthopedic surgery.

Increased Bite Distance From the Edge Lowers Risk of Pullout of Simple Sutures from Acellular Dermal Allograft.

PURPOSE: To investigate whether pullout strength in the acellular dermal allograft matrix (ADM) used for superior capsule reconstruction depends on the distance from the edge of the graft. METHODS: ADM used for superior capsule reconstruction was obtained and cut into 30 squares. Two sutures were placed through the center of each graft by using a loaded Keith needle and forming a simple stitch. The grafts were divided into 3 groups of 10 grafts with a distance of 5 mm, 10 mm or 15 mm from the closest edge of the graft, respectively. The grafts were then preloaded to 5 N and pulled to failure at a rate of 12 mm/s on an MTS 858 MiniBionix servohydraulic mechanical test frame. The load to failure was recorded as well as the stiffness of each graft. RESULTS: The mean load to failure was 34.5 N (SD 7.89) for the 5 mm grafts, 31.7 N (SD 5.99) for the 10 mm grafts, and 66.2 N (SD 18.4) for the 15 mm grafts. There was a significant difference (< 0.0001) between the large grafts (15 mm) and the 2 smaller grafts (10 mm, 5 mm). There was no significant difference in stiffness between the groups of graft (P 0.40). CONCLUSION: Placing the suture at least 15 mm from the edge of the graft increases the graft's ultimate yield strength to suture pullout. CLINICAL RELEVANCE: The depths of the suture in ADM could improve pullout strength for constructs of superior capsular reconstructions.

Over 30% of Systematic Reviews and Meta-analyses Focused on Rotator Cuff Tear Treatments Contained Spin in the Abstract.

PURPOSE: The purpose of this study is to determine the prevalence of spin in the abstracts of systematic reviews and meta-analyses on treatments for rotator cuff tears and whether various study and publishing journal characteristics were associated with the presence of spin. METHODS: A search strategy was developed for Ovid MEDLINE and Ovid Embase to retrieve systematic reviews focused on treatments for rotator cuff tears. For an article to be included, it must meet the following criteria: (1) the article must be a systematic review with or without a meta-analysis, (2) the article must pertain to the treatment of rotator cuff tears, (3) the article must only contain human subjects, and (4) the article must be accessible in English. Systematic reviews were analyzed for spin using a previously developed classification scheme in a masked, duplicate manner. Binary logistic regression was used to examine independent associations via unadjusted odds ratios and 95% confidence intervals between the presence of spin and study characteristics. RESULTS: Search queries returned 932 articles, of which 121 systematic reviews and meta-analyses were eligible. A total of 36.4% (44/121) of systematic reviews contained spin. Among the general characteristics evaluated, there were no correlations with spin. CONCLUSIONS: Spin was present in more than one-third of systematic reviews and meta-analyses covering rotator cuff tear treatments. Spin was not associated with any general study or journal characteristics, which indicates that clinicians must be aware of the potential presence of spin in all such abstracts. CLINICAL RELEVANCE: Clinicians rely on systematic reviews and meta-analyses, especially abstracts of these articles, to provide succinct guidance on best practices in patient care. The presence of spin could adversely affect patient care; thus, steps should be taken to improve the reporting quality of abstracts on rotator cuff tear treatment.

An analysis of Google Trends following athletic injuries by high profile NBA players during the 2019 NBA finals.

CONTEXT: Injuries are common among high profile players in the National Basketball Association (NBA), and could provide an opportunity for physicians to provide accurate sports injury information and reliable rehabilitation data to the general public in the immediate aftermath. OBJECTIVES: To evaluate social media trends to investigate public interest in athletic injuries in the NBA and to evaluate the length of maintained interest in these injuries. METHODS: The Google Trends tool was used to analyze search data around two high profile players-Kevin Durant and Klay Thompson-who suffered injuries during the 2019 NBA Finals. The results were compared to the expected search forecast derived from an autoregressive integrated moving algorithm model. RESULTS: Both players were associated with a mean increase of 1,052.4% (standard deviation [SD], 703.96%) in relative search volumes for terms related to their injuries. This data showed a significant increase in search engine activity related to injuries associated with NBA players in the first 6.13 days (SD, 3.14 days) following the injuries, marking a substantial timeframe for public engagement. CONCLUSIONS: Search traffic information may be beneficial to the sports medicine community, as social media can provide a platform for patient education in a limited timeframe. By increasing patient awareness and knowledge regarding athletic injuries, social media can expand the pool of potential patients for physicians and surgeons.

Public Online Interest in Injuries Sustained by National Football League Quarterbacks.

PURPOSE: To use Google search data to determine the public's interest in learning about athletic injuries sustained by NFL quarterbacks and to investigate how long this interest persists after the injuries. METHODS: We identified starting NFL quarterbacks during the 2019-2020 season online and used the official NFL injury report to determine whether an injury had occurred to a quarterback. We used the Google Trends tool to analyze search trends around a quarterback's injuries from July 22, 2019, to October 22, 2019. Google trends data was extracted as relative search volume over time. We then compared the results to the expected search forecast derived from an autoregressive integrated moving algorithm (ARIMA) model. RESULTS: All 6 injured quarterbacks were associated with increases (64% to 100%) in relative search volumes for terms related to their injury. Furthermore, the data showed a consistent increase in search engine activity around the injuries associated with NFL quarterbacks in the first 3 days, marking a particularly influential time frame for public engagement. CONCLUSION: Our data show an increase in Google traffic surrounding the injuries of prominent NFL quarterbacks within the first 3 days following their injuries. CLINICAL RELEVANCE: Social media can provide a platform for patient education through increasing patient awareness and knowledge regarding athletic injuries.

High Prevalence of Nontraumatic Shoulder Pain in a Regional Sample of Female High School Volleyball Athletes.

BACKGROUND: Shoulder pain is becoming increasingly problematic in young players as volleyball gains popularity. Associations between repetitive motion and pain and overuse injury have been observed in other overhand sports (most notably baseball). Studies of adult athletes suggest that there is a shoulder pain and overuse problem present in volleyball players, but minimal research has been done to establish rates and causes in juvenile participants. PURPOSE: To establish rates of shoulder pain, regardless of whether it resulted in a loss of playing time, in female high school volleyball players. A secondary goal was to determine whether high repetition volumes correlated with an increased likelihood of experiencing pain. STUDY DESIGN: Descriptive epidemiology study. METHODS: A self-report survey focusing on the prevalence of pain not associated with a traumatic event in female high school youth volleyball players was developed. Survey questions were formulated by certified athletic trainers, experienced volleyball coaches, and biomechanics experts. Surveys were received from 175 healthy, active high school volleyball players in Iowa, South Dakota, and Minnesota. RESULTS: Forty percent (70/175) of active high school volleyball players remembered experiencing shoulder pain not related to traumatic injury, but only 33% (23/70) reported taking time off to recover from the pain. Based on these self-reported data, activities associated with significantly increased risk of nontraumatic shoulder pain included number of years playing competitive volleyball (P = .01) and lifting weights out of season (P = .001). Players who reported multiple risk factors were more likely to experience nontraumatic shoulder pain. CONCLUSION: When using time off for recovery as the primary injury criterion, we found that the incidence of shoulder pain is more than twice as high as the incidence of injury reported by previous studies. Findings also indicated that the incidence of shoulder pain may be correlated with volume of previous volleyball experience.

Areas of Agreement and Disagreement Regarding Ponderosa Pine and Mixed Conifer Forest Fire Regimes: A Dialogue with Stevens et al.

In a recent PLOS ONE paper, we conducted an evidence-based analysis of current versus historical fire regimes and concluded that traditionally defined reference conditions of low-severity fire regimes for ponderosa pine (Pinus ponderosa) and mixed-conifer forests were incomplete, missing considerable variability in forest structure and fire regimes. Stevens et al. (this issue) agree that high-severity fire was a component of these forests, but disagree that one of the several sources of evidence, stand age from a large number of forest inventory and analysis (FIA) plots across the western USA, support our findings that severe fire played more than a minor role ecologically in these forests. Here we highlight areas of agreement and disagreement about past fire, and analyze the methods Stevens et al. used to assess the FIA stand-age data. We found a major problem with a calculation they used to conclude that the FIA data were not useful for evaluating fire regimes. Their calculation, as well as a narrowing of the definition of high-severity fire from the one we used, leads to a large underestimate of conditions consistent with historical high-severity fire. The FIA stand age data do have limitations but they are consistent with other landscape-inference data sources in supporting a broader paradigm about historical variability of fire in ponderosa and mixed-conifer forests than had been traditionally recognized, as described in our previous PLOS paper.

Outcomes following microfracture of full-thickness articular cartilage lesions of the knee in adolescent patients.

The purpose of this study was to document outcomes following microfracture for full-thickness cartilage defects of the knee in adolescents. Our hypothesis was that patients aged 18 years or less would have excellent outcomes and function following microfracture of full-thickness knee articular cartilage defects. This study was approved by the Institutional Review Board. Patients < 19 years old with full-thickness knee articular cartilage defects treated with microfracture between January 1992 and June 2008 were identified. Surgical, demographic data, Lysholm score, Tegner activity scale, and patient satisfaction were collected prospectively. A total of 26 patients (14 females, 12 males) met inclusion criteria. Average age was 16.6 years (range: 12-18.9 years). Ninety-six percent of lesions were patellar (37%) or femoral condyle defects (medial 26%, lateral 33%). Minimum 2-year follow-up was obtained in 22/26 patients (85%) with average follow-up of 5.8 years (range: 2.0-13.3 years). Average postoperative Lysholm score was 90 (range: 50-100). Median Tegner scale was 6 (range: 2-10). Median patient satisfaction with outcome was 10 (range: 1-10). Lysholm correlated with Tegner scale (rho = 0.586; p = 0.011) and patient satisfaction (rho = 0.70; p = 0.001). Average postoperative Lysholm score in males was 93 and 86 in females (p = 0.22). One patient underwent revision microfracture. This study showed that adolescent patients who underwent microfracture for treatment of full-thickness knee chondral defects demonstrated increased activity levels and excellent function following surgery.

Outcomes after knee microfracture of chondral defects in alpine ski racers.

Articular cartilage defects of the knee have been shown to cause pain, swelling, decreased function, and suboptimal athletic performance. Treatment of elite-level athletes presenting with full-thickness chondral defects of the knee continues to be a challenge for orthopedic surgeons. The purpose of this study was to document outcomes in elite professional alpine ski racers after microfracture surgery. This study was approved by an institutional review board. All patients who competed in professional ski races recognized by International Ski Federation and had a full-thickness knee articular cartilage defect, treated with microfracture, by a single surgeon, were included in the study. All data were collected prospectively. At minimum 2 years following microfracture, all patients completed a questionnaire, including Lysholm score, Tegner activity scale, and patient satisfaction with outcome. Minimum 2-year follow-up was available for 18 of 20 skiers (90%) at an average follow-up of 77 months (range, 24-255 months). Size of knee articular cartilage defect was larger in males (195 mm(2)) compared with females (155 mm(2)); however, this difference was not statistically significant (p > 0.05). Median postoperative Tegner activity scale was 10 (range, 4-10). Mean postoperative Lysholm score was 86 (range, 41-100). Median postoperative patient satisfaction score was 10 (range, 9-10). Out of the 20 skiers, 19 (95%) returned to competitive skiing. The age of the skier who did not return was 28 years. The average time from surgery to return to competition was 13.4 months (range, 0.5-25.3 months). Average end-of-season overall World Cup ranking was calculated for the nine skiers before and after surgery. Of these nine skiers, six had an improved average overall World Cup ranking after microfracture. In this study, patient satisfaction with outcome and function were high following microfracture of full-thickness chondral lesions of the knee. Nearly all skiers returned to full competition. Microfracture is an acceptable treatment option for elite skiers who have full thickness articular cartilage lesions of the knee.

Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America.

There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of historical fire regimes in the ponderosa pine and mixed-conifer forests of western North America is therefore needed to define reference conditions and help maintain characteristic ecological diversity of these systems. We compiled landscape-scale evidence of historical fire severity patterns in the ponderosa pine and mixed-conifer forests from published literature sources and stand ages available from the Forest Inventory and Analysis program in the USA. The consensus from this evidence is that the traditional reference conditions of low-severity fire regimes are inaccurate for most forests of western North America. Instead, most forests appear to have been characterized by mixed-severity fire that included ecologically significant amounts of weather-driven, high-severity fire. Diverse forests in different stages of succession, with a high proportion in relatively young stages, occurred prior to fire exclusion. Over the past century, successional diversity created by fire decreased. Our findings suggest that ecological management goals that incorporate successional diversity created by fire may support characteristic biodiversity, whereas current attempts to "restore" forests to open, low-severity fire conditions may not align with historical reference conditions in most ponderosa pine and mixed-conifer forests of western North America.

Treatment of adolescent tibia vara with hemiepiphysiodesis: risk factors for failure.

BACKGROUND: Lateral tibial hemiepiphysiodesis is an accepted surgical treatment for skeletally immature patients with adolescent tibia vara. However, the results of this procedure are unpredictable. This study was conducted to identify the risk factors associated with failure of hemiepiphysiodesis. METHODS: We studied patients with adolescent tibia vara who were at least ten years of age, had open physes, had been treated with a lateral hemiepiphysiodesis, and had been followed for at least two years. The mechanical axis deviation, medial proximal tibial angle, and lateral distal femoral angle were measured on radiographs preoperatively, at six months postoperatively, and at the time of final follow-up. Failure was defined as a residual varus deformity requiring osteotomy or a mechanical axis deviation exceeding 40 mm (moderate or severe varus) at the time of final follow-up. RESULTS: Forty-nine patients (forty-six male) with a total of sixty-four involved extremities met the inclusion criteria. The average age was 13.4 years, the average body mass index was 40.7 kg/m(2), and the average duration of follow-up was 3.3 years. The lateral hemiepiphysiodesis was unsuccessful in 66% of the patients. In a multivariate Cox proportional hazards regression analysis, the variables associated with a higher risk of failure included an age of fourteen years or more (hazard ratio = 3.9, p = 0.0009) and a body mass index of > or =45 kg/m(2) (hazard ratio = 2.8, p = 0.01). Greater deformity at baseline as indicated by a smaller medial proximal tibial angle was also found to be a significant factor in the multivariate analysis (p = 0.03). CONCLUSIONS: Lateral hemiepiphysiodesis may be a valuable treatment option for non-morbidly obese patients with less severe adolescent tibia vara, but it is likely to fail in older adolescents with a high body mass index and greater deformity.

Over the falls? Rapid evolution of ecotypic differentiation in steelhead/rainbow trout (Oncorhynchus mykiss).

Adaptation to novel habitats and phenotypic plasticity can be counteracting forces in evolution, but both are key characteristics of the life history of steelhead/rainbow trout (Oncorhynchus mykiss). Anadromous steelhead reproduce in freshwater river systems and small coastal streams but grow and mature in the ocean. Resident rainbow trout, either sympatric with steelhead or isolated above barrier dams or waterfalls, represent an alternative life-history form that lives entirely in freshwater. We analyzed population genetic data from 1486 anadromous and resident O. mykiss from a small stream in coastal California with multiple barrier waterfalls. Based on data from 18 highly variable microsatellite loci (He = 0.68), we conclude that the resident population above one barrier, Big Creek Falls, is the result of a recent anthropogenic introduction from the anadromous population of O. mykiss below the falls. Furthermore, fish from this above-barrier population occasionally descend over the falls and have established a genetically differentiated below-barrier subpopulation at the base of the falls, which appears to remain reproductively isolated from their now-sympatric anadromous ancestors. These results support a hypothesis of rapid evolution of a purely resident life history in the above-barrier population in response to strong selection against downstream movement.