Charm CP Violation and the Electric Dipole Moments from the Charm Scale

The reported CP asymmetry in D->K^+K^- / pi^+pi^- is argued to be too large to naturally fit the SM. If so, a new source of CP violation is implied in the Delta C=1 sector with a milliweak strength. CP-odd interactions in the flavor-diagonal sector are strongly constrained by the EDMs placing severe limitations on the underlying theory. While the largest effects usually come from the New Physics energy scale, they are strongly model-dependent. Yet the interference of the CP-odd forces manifested in D decays with the conventional CP-even Delta C=1 weak interaction generates at the charm scale a background level. It has been argued that the d_n in the SM is largely generated via such an interference, with mild KM-specific additional suppression. The reported CP asymmetry is expected to generate d_n of 30 to 100 times larger than in the SM, or even higher in certain model yet not quite natural examples. In the SM the charm-induced loop-less |d_n| is expected around 10^{-31}e*cm. On the technical side, we present a compact Ward-identity--based derivation of the induced scalar pion-nucleon coupling in the presence of the CP-odd interactions, which appears once the latter include the right-handed light quarks.Comment: 29pages, 5 figure

Plate Fixation of Metatarsal Shaft and Neck fractures has high union rates and low rates of hardware removal

Category: Midfoot/Forefoot, Trauma Introduction/Purpose: Despite large numbers of traumatic 1st,2nd,3 rd, and 4th (1-4 MT) metatarsal shaft and neck fractures, there have be very few outcome studies related to their treatment. K- wire fixation of metatarsal fractures has been shown to lead to poor outcomes when residual displacement and angulation occurs. In order to maintain anatomic alignment, some surgeons use plates for fixation of metatarsal fractures. To the best of our knowledge, this is the first study to report the healing rates, fracture angulation and need for hardware removal of operatively treated 1-4 MT shaft and neck fractures with plate fixation. Methods: In this retrospective cohort study, we reviewed the medical records of all metatarsal fractures at our institution from October 1, 2006 – December 31, 2014 to identify all 1-4 MT shaft and neck fractures. All tarsometatarsal joint factures, isolated 5th metatarsal fractures, fractures treated at outside facilities, skeletally immature patients and fractures treated non operatively were excluded. Final available x-rays with a minimum of one year follow-up from the date of surgery were reviewed. Medical records and x-rays were reviewed for evidence of union, sagittal and coronal fracture angulation (degrees), time to full weight bearing, plate size, fracture location (neck vs shaft) and number of screws on each side of the fracture. Patients were also called to see if the plates were bothersome, if the plates had been removed, or if they desired to have the plate removed. Multiple linear regression analysis was used to make calculations of statistical significance. Results: 45 patients with 75 metatarsal fractures treated with plate fixation were included. All fractures went to union and full weight bearing. Average time to union and full weight bearing was 10.9 and 7.5 weeks respectively. The average coronal and sagittal plane angulation was 3.9 degrees and 2.2 degrees. No demographic variable showed statistical significance with regards to sagittal and coronal angulation. Fractures located in the neck were found to have higher coronal plane angulation malunion compared to fractures in the shaft (P=0.019). No variable was related to final sagittal plane angulation. 28/45 patients responded to our telephone interview with an average follow-up of 4.4 years. 10 stated the plate bothered them. No plates had been removed and 27/28 patients did not want the plate removed. Conclusion: Metatarsal fractures fixed with plates show high rates of union and low final fracture angulation. Patients did not report symptomatic hardware and did not desire to have plates removed. No patient included in this study underwent hardware removal

Total Ankle Arthroplasty

Category: Ankle, Ankle Arthritis Introduction/Purpose: The number of total ankle arthroplasties (TAA) performed in the United States has risen significantly in recent years. Additionally, utilization of an orthopaedic specialty hospital (OSH) to treat healthy patients undergoing elective surgery is becoming more common. The effect of OSH utilization on post-operative outcomes following TAA has yet to be investigated. The purpose of this study is to compare post-operative outcomes following TAA at an OSH when compared to a matching population of patients undergoing TAA at an academic teaching hospital (ATH). Methods: We identified all primary, atraumatic TAA from January 2014 to December 2014 at the OSH and January 2010 to January 2016 at the ATH. Each OSH patient was manually matched to a corresponding ATH patient by clinical variables (age adjusted Charlson comorbidity index [AACCI], 17 individual comorbidity categories, and body mass index [BMI] and demographic variable (age, gender, and insurance type). Matching was performed in a blinded fashion to outcomes. Outcomes analyzed were LOS, 30-day readmissions, mortality, reoperation, and inpatient rehabilitation utilization. Results: There were 40 TAA patients in each group. OSH and ATH patients were similar in age (66.7 versus 66.8 yo, p=0.95), BMI (both 28.4, p=1.00), age-adjusted Charlson Comorbidity Index (both 3.3, p=1.00), and gender (both 45.0% male, p=1.00). Average LOS for TAA at the OSH was 1.28+/-0.51 compared to 2.03+/-0.89 (p<0.001) at the ATH. No OSH patients were readmitted within 30 days, compared to 2 ATH (5.0%; p=0.15). Two OSH patients (5.0%) and two ATH patients (5.0%; p=1.00) required reoperation. There were no mortalities in either group. No OSH patients utilized inpatient rehabilitation compared to 3 ATH patients (7.5%; p=0.078). When excluding patients utilizing inpatient rehabilitation, patients at the OSH still demonstrated significantly lower LOS (1.28+/-0.51 vs 1.81+/-0.69 days; p<0.001). No OSH patients required transfer. Conclusion: Primary TAA performed at an OSH had significantly shorter LOS when compared to a matched patient treated at an ATH with no significant difference in readmission or reoperation rates. Additionally, patients who had their procedure performed at an OSH utilized inpatient rehabilitation less frequently than those at an ATH. This study suggests that performing TAA at an OSH offers a potential source of significant healthcare savings

A Supine Achilles Tendon Repair Decreases Total Operating Room and Anesthesia Time Without Sacrificing Outcomes

Category: Ankle, Sports, Trauma Introduction/Purpose: Achilles tendon repairs have traditionally been performed using a prone position. Prone positioning gives the surgeon easy visualization of the tendon, but may not offer the safest position for anesthesia and requires more peri-operative positioning time. We propose that the use of a supine position for primary Achilles tendon repairs offers similar surgical times, while saving non-surgical operating room time during positioning and anesthesia set-up. Methods: A retrospective review of primary Achilles tendon repairs done at our institution’s surgical sites between March of 2010 and July of 2015 was performed. Using the institutional database, 145 procedures were identified. Chart review demonstrated that 82 were performed open-supine (OS), 31 were performed open-prone(OP), and 32 were performed percutaneous-prone(PP). Surgical, non-surgical, and total operating room times were compared between the three groups. Results: Average surgical times were 32.8, 49, and 32.3 minutes for the OS, OP, and PP procedures, respectively. Total operating rooms times were 59.1, 88.9, and 76.7; while non-surgical times spent in the operating rooms were 26.3, 39.9, and 44.4 minutes for these groups, respectively. Achilles tendons repaired either OP or PP resulted in an additional 13.6 and 18.1 (average 15.9) minutes of operating room time. There was not an increase in complications with the supine procedure compared to the prone procedures. Conclusion: Primary Achilles tendon repairs can be performed effectively using an open technique in a supine position, saving non-surgical operating room time without increasing complications. The supine position may also offer a safer method of providing anesthesia to these patients by allowing the anesthesiologist a more accessible airway and decreasing the risks involved with placing an intubated patient into a prone position

Content Relevance of the Foot and Ankle Ability Measure in Patients with Achilles Tendon Diseases

Category: Sports Introduction/Purpose: The Foot and Ankle Ability Measure (FAAM) is a widely used evaluative, region-specific patient reported outcome measure. Its construct validity, test-retest reliability, and responsiveness are reasonably well supported in patients with a variety of lower extremity musculoskeletal conditions. However, since its development, the FAAM’s content relevance has never been subject to patient assessment. Therefore, this study was designed to assess the content relevance of the FAAM among patients with Achilles tendon diseases. Methods: IRB-approved, prospective, observational study of patients with Achilles tendon diseases. Subjects gave informed consent to complete a standard FAAM and a FAAM content relevance questionnaire. For each item of the relevance questionnaire, the standard FAAM’s visual analogue scale was replaced by a categorical scale asking subjects to rank the individual item as 1-Not Relevant, 2-Somewhat Relevant, or 3-Very Relevant to their lower extremity condition. The same was asked regarding both the entire ADL and Sports subscales, respectively. Descriptive statistics (mean, standard deviation) were calculated using pooled individual question scores and then 95% confidence intervals were constructed. Any individual item or subscale with a mean score above 2.0 was considered to have substantial content relevance. Floor and ceiling effects were deemed to have been present if 20% or more of patients gave all items of a subscale either the lowest or highest possible scores, respectively. Results: There were 59 respondents with mean age of 52.6 years (range, 28 to 79 years). Mean time from presentation to content relevance assessment was 19.6 weeks (range, 1 to 100 weeks). There were 39 (66%) surgical patients and 20 (34%) nonsurgical patients. Diagnoses included 28 (47%) rupture, 18 (31%) tendinosis, and 13 (22%) paratenonitis. 10 (17%) were pre- treatment and 49 (83%) post-treatment. For each individual item and subscale, the mean relevance was above 2.0 indicating substantial relevance. The 95% confidence interval crossed below this threshold for only one item, ‘Personal Care’ (mean 2.02, 95% CI 1.79 to 2.24). No floor effects were detected. Ceiling effects were apparent for only the Sports subscale (n=25,42.4%). Conclusion: These findings demonstrate that the FAAM has substantial item and subscale-level content relevance in patients with Achilles tendon diseases. Future work should aim to provide additional psychometric data specific to patients with Achilles tendon diseases in order to allow more precise use of the FAAM in this specific patient population