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Purpose Distal femoral growth arrest can result in progressive deformities and functional disability. The treatment is challenging given the significant growth potential of the distal femoral physis. This study addresses the short-term outcomes after distal femoral physeal bar resection combined with guided growth for the treatment of angular limb deformity. Methods We conducted a retrospective analysis of patients treated with distal femoral physeal bar resection, fat graft interposition, and growth modulation with a tension-band plate. Data recorded included patient demographics, growth arrest cause, physeal bar size, time-to-surgery, details of the operative procedure, and complications. The mechanical axis zones, tibiofemoral angle, and the anatomic lateral distal femoral angle were assessed on 51-inch anteroposterior standing radiographs. Results Five patients (3 male individuals) with valgus (n=4) and varus deformities (n=1) due to physeal arrests of the distal femur were analyzed. The cause of the physeal arrest was trauma (n=3) and infection (n=2). The average age at the time of surgery was 6.6 years (range: 2 to 11 y). Average size of the physeal bar was 413.4 mm, which represented 16.8% of the total distal femoral physis (range: 12% to 26%). Four of the 5 patients had a total correction of the deformity in 14.3 months (range: 9 to 22 mo). One patient required correction by osteotomy and external fixation. Postoperatively, 1 patient presented no improvement, and 4 had restoration of the longitudinal bone growth and alignment. Two patients had rebound valgus: one is being observed and another has undergone a repeat guided growth procedure. Conclusions Distal femoral physeal bar resection combined with tension-band hemiepiphysiodesis provides a viable option for the correction of angular deformities associated with physeal arrest. Longer follow-up is required to evaluate future growth of the distal femoral physis after this combined procedure. Level of evidence Level IV-therapeutic study.

BACKGROUND Medial epicondyle fractures represent up to 20% of elbow fractures in children and adolescents. There is a growing body of literature to support surgical fixation for displaced fractures. However, controversy regarding imaging modality for displacement measurement and surgical indications remain controversial. The purpose of this survey was to gauge Latin American surgeons' practices and preferences for the evaluation and treatment of medial epicondyle fractures. METHODS A web-based survey containing 19 questions was distributed to active members of SLAOTI (Sociedad Latinoamericana de Ortopedia y Traumatologia Infantil) in November 2018. The survey elicited information regarding surgeon demographics, evaluation methods, the factors involved in the decision to perform surgery, and their experience in cases of symptomatic nonunion. Categorical variables were summarized using frequencies and proportions. Analysis of associations between surgeon demographics and treatment preferences were carried out. RESULTS A total of 193 out of 354 completed questionnaires were returned (54% response rate). In total, 74% of the participants (142/193) favored radiographs for the evaluation of the fracture displacement, and 25.4% (49/193) added a computed tomography scan for a more detailed evaluation. The majority of respondents (48.2%) would consider a 5 mm displacement as the cutoff for surgical treatment, 21.8% 2 mm, 20.7% 10 mm, and 9.3% 15 mm. There were no differences between the experience of the participants, academic versus private setting, or training regarding surgical/nonsurgical management. CONCLUSIONS There are significant differences in opinions between SLAOTI members as to the optimal management of medial epicondyle fractures. Implications of disagreement in evaluation and treatment support the need for multicenter prospective studies to develop evidence-based guidelines for the management of this fracture. LEVEL OF EVIDENCE Level V-expert opinion. Cross-sectional electronic survey.

BACKGROUND Although percutaneous trigger thumb release has been extensively used in adults, the technique is not widespread in children. The purpose of this study was to evaluate the efficacy and safety of percutaneous trigger thumb release in the pediatric age group. METHODS Twenty consecutive thumbs of 15 patients scheduled for surgical release of the A1 pulley were included in this cohort. Each patient received first the percutaneous release (PR) followed by an open release (OR) and served as self-controls. Thumb extension was assessed immediately before PR, after PR, and finally after OR, using a goniometer. Extent of the A1 pulley release, iatrogenic injury to the digital nerve and vessels, and flexor tendon laceration was assessed after PR. The distance between the PR and the digital nerve was measured in millimeters. Comparison between thumb extension after PR and OR was made using a paired t test. RESULTS Preoperative range of motion averaged -45.2 ± 21.7 degrees loss of extension (range, -80 to -10 degrees), decreased to -4 ± 8 degrees loss of extension (range, -25 to 0 degrees) after PR, and to 0 degrees after OR. Clinically, release was complete in 14 cases (70%) and partial in 6 cases (30%). Once the thumb was approached, we confirmed that A1 pulley was completely cut in 4 cases (20%), to >75% in 2 cases (10%), and between 50% and 75% in the remaining 14 cases (70%). There were no neurovascular iatrogenic injuries. Mean distance between the needle and the digital nerve was 2.45 ± 0.9 mm (range, 1 to 4 mm). Lacerations to the flexor tendons were observed in 80% of the cases. CONCLUSIONS We do not recommend PR in the pediatric thumb given the risk of neurovascular iatrogenic injury or incomplete A1 pulley release. LEVEL OF EVIDENCE Level II therapeutic study-prospective comparative study.

BACKGROUND Juvenile osteochondritis dissecans of the talus is rare, and the literature provides little data to guide treatment. The purpose of the present study was to evaluate our clinical and radiographic results with arthroscopic retrograde drilling in patients who were refractory to conservative care. METHODS We retrospectively evaluated all patients with juvenile osteochondritis dissecans of the talus who underwent surgery for the treatment of stable lesions that failed conservative treatment. Medical records were reviewed for symptoms and demographic information. Preoperative and latest postoperative radiographs were used to determine degree of healing. AOFAS Ankle/Hindfoot scale and visual analog scale for pain were used to evaluate clinical outcomes. RESULTS We identified 6 patients (6 ankles). The mean age was 13 years, and the mean duration of follow-up was 37 months (range, 16 to 69 mo). All of them had progressed toward healing and were asymptomatic, but only 3 out of 6 had a complete radiographic healing at last follow-up. The average AOFAS Ankle/Hindfoot score improved from 69 points (55 to 75, IQR=10) preoperatively to 98 points (90 to 100, IQR=7) (P

Climate and crop yield variability associated with El Nino—Southern Oscillation (ENSO) are now predictable within limits. This predictability suggests a potential to tailor agricultural management to mitigate impacts of adverse conditions and to take advantage of favorable conditions. However, improved climate predictions may benefit society only with parallel advances in our ability to use this knowledge. We show that the value that will accrue to any given actor from an ENSO phase forecast should be viewed not as a known number but instead as a random draw from a distribution, even when the forecast is always correct. Forecast value depends on the highly variable contexts in which forecasts are used. Randomness in forecast value has significant implications for choices made by forecasters, forecast users and policy makers. To show randomness, we estimate potential economic values of ENSO forecasts for agricultural producers based on two realistic assumptions: the crop prices farmers receive are uncertain; and within an ENSO phase, the actual climate is variable in ways that affect profits. The use of synthetic weather and crop price series, with crop simulation models, helps show the range and likelihood of climate forecast value.

Some recent studies contend that a simple exhaustive (grid) search through the complete inverse modeling parameter space can be faster than a more sophisticated algorithm such as simulated annealing (SA). The objective of this study was to implement an SA algorithm guaranteed to run worst-case as fast as the grid search. This algorithm resulted from: (1) working on a discrete parameter space similarly to the grid search, and (2) accelerating the optimization by avoiding multiple crop model runs of the same parameter combinations. The latter was achieved by storing simulation results in computer memory and checking for those data before running the model for any given parameter combination. The algorithm was tested relative to a pure grid search in two case studies: a synthetic problem having numerous local minima, and a crop modeling exercise using the CERES-Maize model with two years of observed maize data from 13 locations in a field near Murray, Kentucky. The performance of the modified SA algorithm depended on its parameter values, but a conservative parameter combination was found that ran much faster than the grid search, its run time tending asymptotically to that of the grid search as the number of locations to calibrate grew, while converging to objective function values (and usually parameter values) practically identical to the global optimum, and explaining 97% of the observed yield in the two years used for parameterization. Adoption of this algorithm can reduce parameterization run time on the order of 25% to 75%, depending on the geometry of the simulation domain. Additionally, it can be used to calibrate coupled spatial crop models in which parameter values at one location can affect parameter values at other locations, a task not possible using a grid search. Finally, the proposed algorithm can generate good “first cut” solutions in only a few hundred iterations, an important consideration when designing practical crop simulation applications.

The availability of long-lead ENSO-related climate forecasts has led many to speculate that such forecasts may benefit decision making in agriculture. To explore the conditions required for the effective use of climate forecasts, we conducted a pilot study focused on central-eastern Argentina. Historical records showed higher (lower) average precipitation during warm (cold) ENSO events in November–December. However, variability of the precipitation signal within ENSO phases was high. National-level yields of maize, soybeans and sorghum tended to be higher (lower) during warm (cold) events. A field survey was conducted to identify impediments for forecast adoption and learn how to communicate climate information. Most farmers surveyed know about ENSO, with the 1997–1998 event marking a “turning point” in their awareness of the phenomenon. Finally, various modeling approaches were used to explore outcomes of alternative management options (changes in crop management and land allocation) tailored to climate scenarios associated with each ENSO phase. Simulation exercises identified differences in optimal management between ENSO phases.

A risk assessment framework is presented to characterize the vulnerability of agricultural production systems to El Nino-southern oscillation (ENSO)-related climate variability. The framework was applied to current maize production systems in two locations (Pergamino and Pilar) in the Pampas of central-eastern Argentina. Climatic, agronomic, and economic models were linked to produce probability distributions of farm-level yields and net returns by ENSO phase. Generally, an enhanced chance of higher (lower) simulated maize yields existed during warm (cold) ENSO events. However, regional differences existed: the effect of warm events on yields was more marked in Pilar, but Pergamino showed a proportionally stronger response to cold events. The modeling framework allowed the exploration of outcomes of high and low scenarios of soil water availability at planting time and ENSO phase. High initial soil water availability in Pilar offset increased yield risks from dry conditions associated with cold ENSO events. Fluctuations of output prices were shown to have considerable influence on the risk associated with ENSO-related climate variability. Despite these general results, there was considerable overlap in yields and net returns for the various ENSO phases. This overlap has significant implications for the adoption of ENSO forecasts in agriculture. The risk assessment framework developed here is a necessary precursor to risk management studies that prescribe or describe possible responses to expected climate scenarios.