Long-lasting, deep effect of Saturn's giant storms.

Planetary-scale giant storms erupt on Saturn quasiperiodically. There have been at least six recorded occurrences of past eruptions, and the most recent one was in 2010, with its whole life span captured by the Cassini mission. In 2015, we used the Very Large Array to probe the deep response of Saturn's troposphere to the giant storms. In addition to the remnant effect of the storm in 2010, we have found long-lasting signatures of all mid-latitude giant storms, a mixture of equatorial storms up to hundreds of years old, and potentially an unreported older storm at 70°N. We derive an ammonia anomaly map that shows an extended meridional migration of the storm's aftermath and vertical transport of ammonia vapor by storm dynamics. Intriguingly, the last storm in 2010 splits into two distinct components that propagate in opposite meridional directions, leaving a gap at 43°N planetographic latitude.

Bridging Massive Acetabular Defects With the Triflange Cup: 10- to 28-Year Results.

BACKGROUND: Massive acetabular bone loss, encountered complex primary or revision total hip arthroplasty, remains a reconstructive challenge. The custom triflange cup reliably achieves both early fixation and longer-term stability. This study presents the 10-year minimum three-surgeon follow-up of acetabular defects managed with a custom triflange component. METHODS: All patients who underwent a custom triflange acetabular component implantation from January 1992 to December 2009 were identified. Demographics, implant data, outcomes, and reoperations were collected and analyzed. Bone defects in all cases were Paprosky type IIIA, IIIB, or IV. A total of 233 patients (241 hips) underwent implantation of a custom triflange during the study period. There were 81 patients (83 hips) who died prior to minimum follow-up and 84 patients (88 hips) had minimum follow-up of 10 years (mean 15.2; range, 10 to 28), or failure prior to 10 years. RESULTS: Complications requiring additional surgery occurred in 43 hips (49%). There were 10 revisions for failure (11.4%); four were due to recurrent infection, three for aseptic loosening, and one for recurrent infection with all revised to a new triflange. There was one patient who was resected to a Girdlestone for infection and one patient was revised for infection to a bipolar hemiprosthesis due to a healed discontinuity. CONCLUSION: To our knowledge, this study represents the largest cohort and longest follow-up in the current literature and demonstrates excellent survivorship and clinical results at an average of 15 years follow-up. The component was retained in 89% of cases.

Universal suicide screening in college primary care.

OBJECTIVE: Implementation of a universal primary care (PC) suicide-screening program in a college student health center to heighten awareness, provide support and enhance education of staff and students served. Program feasibility, data collection, electronic medical record (EMR) adaptations and staff learning outcomes were examined. Participants: 1,607 students with PC visits during Spring 2018 semester. Methods: Annual Suicide Behaviors Questionnaire (SBQ-R), EMR template, safety alert, referral tracking and simulated staff training were employed. Chi-square tests assessed documentation, safety alerts and mental health referral changes. Paired t-tests evaluated staff learning outcomes. Results: 12.8% of students screened positively for suicide risk during implementation. Documentation consistency, EMR safety alert utilization, mental health referrals and subsequent appointments increased significantly. Staff learning outcomes yielded growth in knowledge and comfort with suicide screening and brief intervention. Conclusion: A comprehensive suicide-screening program is feasible for identifying students at-risk and promoting positive clinical changes in college PC practice settings.

Comparison of Traditional Molded, First-Generation Premolded, and Second-Generation Premolded Antibiotic-Loaded Polymethylmethacrylate Articulating Spacers for Treatment of Chronic Prosthetic Joint Infection of the Knee.

BACKGROUND: The purpose of this study was to compare patients who had chronic prosthetic joint infection treated using three methods of articulating polymethylmethacrylate spacers in two-stage reimplantation. METHODS: We identified 77 patients who had chronic prosthetic joint infection with a minimum of one-year follow-up. Reinfection rates were determined using modified International Consensus group criteria. RESULTS: The overall reinfection rate was 18% (14 of 77 patients). Despite a higher medical comorbidity in the second-generation spacer cohort, there were no statistical differences in reinfection rates between articulating spacer types. CONCLUSION: This study suggests that there were no differences in efficacy between the traditional molded, first-generation premolded, and second-generation premolded articulating spacers, but more studies with high level of evidence are needed.

Midterm Survivorship After Revision Total Hip Arthroplasty With a Custom Triflange Acetabular Component.

BACKGROUND: Custom triflange acetabular components are being increasingly used for the reconstruction of Paprosky type IIIB acetabular defects. However, midterm survivorship data are lacking. METHODS: We queried the prospective registries at 2 high-volume revision centers for patients who had undergone revision total hip arthroplasty using a custom triflange component between 2000 and 2011. We identified 73 patients with minimum 5-year follow-up. These patients' records were reviewed to determine incidence of revision or reoperation, clinical performance, and radiographic stability. The mean follow-up was 7.5 years (range 5-12 years). RESULTS: Fifteen of 73 triflange components (20.5%) were indicated for revision during the follow-up period, including 6 for instability (8%) and 8 for infection (11%). Twelve of 73 patients (16%) underwent reoperation for reasons other than failure of the triflange component. The median hip disability and osteoarthritis outcome score for joint replacement score at midterm follow-up was 85 (interquartile range 73-100). Only 1 of 73 implants was determined to be radiographically loose at midterm follow-up. CONCLUSION: Custom triflange reconstruction for severe acetabular deficiency is a viable option; however, complications are common and significant challenges remain for those that fail.

Peering through Jupiter's clouds with radio spectral imaging.

Radio wavelengths can probe altitudes in Jupiter's atmosphere below its visible cloud layers. We used the Very Large Array to map this unexplored region down to ~8 bar, ~100 kilometers below the visible clouds. Our maps reveal a dynamically active planet at pressures less than 2 to 3 bar. A radio-hot belt exists, consisting of relatively transparent regions (a low ammonia concentration, NH3 being the dominant source of opacity) probing depths to over ~8 bar; these regions probably coincide with 5-micrometer hot spots. Just to the south we distinguish an equatorial wave, bringing up ammonia gas from Jupiter's deep atmosphere. This wave has been theorized to produce the 5-micrometer hot spots; we observed the predicted radio counterpart of such hot spots.

Assessment of a medial pivot total knee arthroplasty design in a cadaveric knee extension test model.

A total knee has been designed to mimic less-compliant medial and more-compliant lateral behavior. In vivo testing compared open-kinematic chain behaviors of cadaver knees in their normal state and after implantation of the knee prosthesis. Specimen's limbs were computed tomography scanned, and infrared arrays on tibia and femur were registered to bone markers. Motion of the joint and quadriceps force were reported from 90° flexion to full extension. Less medial and more lateral anterior-posterior motion was seen in both the intact and the implanted knees. Tibiofemoral rotation and translation were similar in direction but were reduced in magnitude for the prosthetic knees. Quadriceps force, defined as that applied force required to extend the knee, required after implantation was variable between specimens but not statistically different from the intact condition. The prosthesis tested exhibits kinematic behavior similar to that in their normal state, with no difference in quadriceps force required for extension.

Wear performance of large-diameter differential-hardness hip bearings.

We hypothesized that differential-hardness hard-on-hard bearings would generate less wear debris compared with like-hardness metal-on-metal (M-o-M) bearings. We conducted wear testing on 3 types of large-diameter hard hip bearings: (1) contemporary cast-on-cast ("like" hardness) M-o-M; (2) differential-hardness M-o-M; and (3) differential-hardness ceramic-on-metal. A simulated gait profile ranging from 200 to 2000 N was applied to the bearings at a frequency of 1 Hz for 5 Mc. All bearings were tested in an anatomically inverted position in 90% alpha calf serum. Both differential-hardness bearing systems produced lower run-in wear rates (90%-97%), steady-state wear rate (45%-84%), and total metal wear (68%-88%) compared with the like-hardness bearing system. The ceramic-on-metal bearings exhibited the least wear followed by differential-hardness M-o-M bearings; like-hardness M-o-M bearings exhibited the greatest amount of wear. These findings support our hypothesis that differential-hardness hip bearing systems produce less metallic wear debris than those with like hardness and may result in lower metal ion release in vivo.

Adult Bronchoesophageal Fistula Diagnosed on Computed Tomography.

Tracheoesophageal and bronchoesophageal fistulas are usually diagnosed early in life after an infant presents with difficulty feeding or recurrent pneumonias. These conditions rarely presents in adulthood. We report a case of a 59-year-old woman who presented with cough and recurrent pneumonias. The workup revealed a bronchoesophageal fistula that was diagnosed on CT and confirmed with a barium esophagogram.

Revision total hip arthroplasty for pelvic discontinuity.

BACKGROUND: Revision of a failed total hip arthroplasty with massive acetabular bone loss and pelvic discontinuity is a reconstructive challenge. This report presents the mid-term to long-term results of revision total hip arthroplasty with a custom-made porous-coated triflange acetabular prosthesis in a consecutive series of patients with pelvic discontinuity. METHODS: Twenty-eight consecutive patients (thirty hips) with a failed total hip arthroplasty and pelvic discontinuity underwent revision total hip arthroplasty. The prosthesis was custom-manufactured on the basis of a three-dimensional model of the hemipelvis created with computed tomography. Initial stability of the implant was provided with screw fixation. Two patients did not return for follow-up after three months, and eight died and were followed for less than seven years, leaving twenty hips in eighteen patients followed for a mean of ten years. Harris hip scores and sequential radiographs were used to evaluate the clinical and radiographic results. RESULTS: Definite healing of the pelvic discontinuity was indicated by the presence of bridging callus in eighteen of the twenty hips. There were no broken screws and no cases of implant migration, even when the discontinuity persisted. Small nonprogressive radiolucent lines were observed in six hips. Complications included one partial sciatic nerve palsy that resolved completely and one case of loose ischial screws in a radiographically stable implant in the same patient. Five patients had one or more dislocations postoperatively. The mean Harris hip score improved from 41 points preoperatively to 80 points at the time of the latest follow-up. Eleven of the eighteen patients required ambulatory aids postoperatively. No component was revised. CONCLUSIONS: Performance of a revision total hip arthroplasty with a custom triflange acetabular prosthesis to treat massive acetabular bone loss and pelvic discontinuity can provide a durable solution with good clinical results. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Advantages of milling versus broaching the proximal femur.

Femoral canal preparation in cementless total hip arthroplasty requires either broaching or milling of the proximal femur to create an osseous envelope for component implantation. The purpose of this article is to discuss the merits of milling the proximal femur for implant placement in primary or revision total hip arthroplasty.