Utilization of machine learning to accelerate colloidal synthesis and discovery.

Machine learning techniques are seeing increased usage for predicting new materials with targeted properties. However, widespread adoption of these techniques is hindered by the relatively greater experimental efforts required to test the predictions. Furthermore, because failed synthesis pathways are rarely communicated, it is difficult to find prior datasets that are sufficient for modeling. This work presents a closed-loop machine learning-based strategy for colloidal synthesis of nanoparticles, assuming no prior knowledge of the synthetic process, in order to show that synthetic discovery can be accelerated despite limited data availability.

American College of Foot and Ankle Surgeons Clinical Consensus Statement: Appropriate Clinical Management of Adult-Acquired Flatfoot Deformity.

This clinical consensus statement of the American College of Foot and Ankle Surgeons focuses on the highly debated subject of the management of adult flatfoot (AAFD). In developing this statement, the AAFD consensus statement panel attempted to address the most relevant issues facing the foot and ankle surgeon today, using the best evidence-based literature available. The panel created and researched 16 statements and generated opinions on the appropriateness of the statements. The results of the research on this topic and the opinions of the panel are presented here.

Tensiomyographical responses to accelerometer loads in female collegiate basketball players.

The purpose of the present study was to characterise the relationship between relative versus absolute internal and external loads in collegiate basketball players throughout the course of a season. Five Division I basketball players wore triaxial accelerometers throughout the 2015-2016 season and were tensiomyographically assessed weekly. One-way repeated-measure analysis of variance (RM ANOVA) with least-significant-difference (LSD) pairwise comparisons was used to determine which absolute weekly loads were different across the season. Cohen's d was used to supplement the determination of meaningful relative load changes. Overall RM ANOVA models suggest absolute external load differences occurred (PlayerLoad™ F = 17.63; IMA™ F = 31.63). Two-way RM ANOVA models revealed main effect differences were revealed between muscle groups for Tc (F = 9.11) and Dm (F = 3.25). Meaningful relative load changes between weeks were observed for both external and internal. The present study observed that tensiomyography utilised as a tool to monitor internal load may be more suitable for detecting fatigue from relative external load changes versus absolute load attained. Limiting weekly training volume changes to ≤10% may maintain appropriate adaptation. Mediolateral plane IMA™ and adductor longus muscle group may be pertinent metrics when monitoring female collegiate basketball athletes.

Union Rates and Complications of Lateral Column Lengthening Using the Interposition Plating Technique: A Radiographic and Medical Record Review.

Lateral column lengthening is a common procedure for correction of pes planovalgus. A tricortical bone graft has been a standard among foot and ankle surgeons. The purpose of the present study was to compare the union rates and complications between the 2 forms of fixation for lateral column lengthening. The present study was a retrospective medical record and radiograph review of 52 patients divided into 2 equal groups, allograft (group A) and opening wedge plate (group B). The radiographic analyses compared the preoperative, postoperative and long-term measurements of cuboid abduction and talonavicular angles. The outcome measures included nonunion, hardware removal, and infection. The median follow-up duration for each group was 34.5 (range 6.3 to 89.5) months and 12.6 (range 6.5 to 56.8) months for groups A and B, respectively. Group A had 4 nonunions (15.4%) and group B had 2 nonunions (7.7%). The mean radiographic measurements of cuboid abduction and talonavicular articulation for each group improved significantly. The incidence of hardware removal was greater for group A than for group B (30.8% versus 15.4%), although the difference was not statistically significant. The median time to osseous healing for group A was 12.0 (range 8.0 to 80.0) weeks and for group B was 10.0 (range 6.0 to 36.0) weeks. The interposition plating techniques for lateral column lengthening procedures had a lower nonunion rate and incidence of hardware removal compared with the traditional use of tricortical bone grafting. The findings from the present study will aid surgeons in alternative fixation for lateral column lengthening procedures.

Calcaneonavicular Coalition Resection With Pes Planovalgus Reconstruction.

Calcaneonavicular coalitions can lead to a painful, rigid pes planovalgus deformity. Historical treatment of coalitions recommends resection. A newer concept in coalition treatment includes concomitant flatfoot reconstruction. In the present study, we hoped to demonstrate the ability to reconstruct a flatfoot deformity with concomitant calcaneonavicular coalition resection. We performed a retrospective comparative study of patients undergoing isolated calcaneonavicular bar excision (group A) with those undergoing calcaneonavicular bar excision and concomitant pes planovalgus reconstruction (group B). The radiographic parameters of pes planovalgus correction were measured on the pre- and postoperative radiographs, including talar head uncoverage, calcaneal inclination, and anteroposterior and lateral talo-first metatarsal angle. Calcaneonavicular coalition resection was performed using a standard technique with or without biologic spacers. Associated flatfoot reconstruction included posterior muscle group lengthening, calcaneal osteotomy, and/or midfoot osteotomy. Of the 27 patients, 20 were included in group A and 7 in group B. Their mean age was 18.1 years. Improvement was seen in the radiographic parameters for patients undergoing calcaneonavicular bar excision with concomitant flatfoot procedures, with statistical significance found in the calcaneal inclination (p = .013). Talar head uncoverage improved in both groups (p = .011). No change was found in the radiographic angles in patients undergoing isolated calcaneonavicular bar excision. No patients in either group developed recurrence of the coalition. The results of the present study demonstrated radiographic improvement in patients undergoing calcaneonavicular bar excision with concomitant pes planovalgus reconstruction. Hindfoot reconstruction with joint sparing osteotomies during coalition excision is a reasonable option to improve alignment and avoid arthrodesis.

Symptomatic Hardware Removal After First Tarsometatarsal Arthrodesis.

Severe hallux valgus deformity with proximal instability creates pain and deformity in the forefoot. First tarsometatarsal joint arthrodesis is performed to reduce the intermetatarsal angle and stabilize the joint. Dorsomedial locking plate fixation with adjunctive lag screw fixation is used because of its superior construct strength and healing rate. Despite this, questions remain regarding whether this hardware is more prominent and more likely to need removal. The purpose of the present study was to determine the incidence of symptomatic hardware at the first tarsometatarsal joint and to determine the incidence of hardware removal resulting from prominence and/or discomfort. A review of 165 medical records of consecutive patients who had undergone first tarsometatarsal joint arthrodesis with plate fixation was conducted. The outcome of interest was the incidence of symptomatic hardware removal in patients with clinical union. The mean age was 55 (range 18.4 to 78.8) years. The mean follow-up duration was 65.9 ± 34.0 (range 7.0 to 369.0) weeks. In our cohort, 25 patients (15.2%) had undergone hardware removed because of pain and irritation. Of these patients, 18 (72.0%) had a locking plate and lag screw removed, and 7 (28.0%) had crossing lag screws removed. The fixation of a first tarsometatarsal joint fusion poses a difficult situation owing to minimal soft tissue coverage and the inherent need for robust fixation to promote fusion. Hardware can become prominent postoperatively and can become painful and/or induce cutaneous compromise. The results of the present observational investigation imply that surgeons can reasonably inform patients that the incidence of symptomatic hardware removal after first tarsometatarsal arthrodesis is approximately 15% within a median duration of 9.0 months after surgery.

Short-Term Radiographic Results and Technique of Tibiotalocalcaneal Arthrodesis With a Posterior Anatomic Locking Plate.

Tibiotalocalcaneal arthrodesis is a salvage procedure for severe hindfoot/ankle deformities, arthritis, avascular necrosis of the talus, failed total ankle replacement, and Charcot neuroarthropathy. The methods for fixation include anterior and lateral plates, screws, retrograde intramedullary nails, and external fixation. The purpose of the present report was to describe the short-term radiographic outcomes and technique using a posterior approach with an anatomic-specific locking plate for tibiotalocalcaneal arthrodesis. Nine patients underwent tibiotalocalcaneal arthrodesis using a posterior locking plate. The medical records and radiographs were retrospectively reviewed for patient demographics, fusion rate, complications, and patient satisfaction. The mean patient age was 57.89 ± 10.8 years, and the follow-up period was 11.11 ± 4.74 months for the patients undergoing posterior tibiotalocalcaneal arthrodesis. The mean time to weightbearing in a shoe with a brace was 16.68 weeks. The ankle and subtalar joints had healed within a mean duration of 13.61 ± 2.96 weeks. Two patients (22%) developed nonunion, 1 at both the ankle and subtalar joint and 1 at the ankle only. The present report demonstrates an alternative posterior approach to joint preparation and fixation. Direct visualization of both joints and soft tissue coverage provide a viable option for posterior fusion in patients with compromised anterior and/or lateral skin envelopes.

Posterior approach for medial column beam screw in midfoot Charcot reconstruction: technique and structures at risk.

Charcot neuroarthropathy is frequently recognized as a major cause of morbidity in patients with neuropathic diabetes mellitus. Recently, intramedullary beam screw fixation has been used for midfoot Charcot reconstructions. Ten below-the-knee cadaveric specimens were used to demonstrate an antegrade, posterior approach for placement of a medial column beam screw, with specific attention to the proximity of the anatomic structures at risk. Six structures at risk were identified, including the sural nerve, ankle joint, flexor hallucis longus tendon, Achilles tendon, neurovascular bundle, and peroneal tendon sheath. The sural nerve was the most commonly injured structure, injured in 50% of the limbs. The Achilles and flexor hallucis longus tendons were injured in 20% and the ankle joint in 10% of the limbs. The neurovascular bundle and peroneal tendon sheath were located over 1 cm from the reference guidewire and were considered safe structures in this approach. Our results have demonstrated an alternative posterior approach to the delivery of an intramedullary medial column beam screw, instead of a retrograde technique beginning in the metatarsal heads. Our results have also made clear the need to be aware of the potential for damage to the sural nerve, Achilles tendon, flexor hallucis longus tendon, and ankle joint.

Electrothermal instability mitigation by using thick dielectric coatings on magnetically imploded conductors.

Recent experiments on Sandia's Z facility have confirmed simulation predictions of dramatically reduced instability growth in solid metallic rods when thick dielectric coatings are used to mitigate density perturbations arising from an electrothermal instability. These results provide further evidence that the inherent surface roughness as a result of target fabrication is not the dominant seed for the growth of magneto-Rayleigh-Taylor instabilities in liners with carefully machined smooth surfaces, but rather electrothermal instabilities that form early in the electrical current pulse as Joule heating melts and vaporizes the liner surface. These results suggest a new technique for substantially reducing the integral magneto-Rayleigh-Taylor instability growth in magnetically driven implosions, such as cylindrical dynamic material experiments and inertial confinement fusion concepts.

Surgical considerations for the neglected or chronic Achilles tendon rupture: a combined technique for reconstruction.

The Achilles tendon is among the most commonly injured tendons in the human body. The most common reason for delayed treatment is a missed diagnosis or a deficiency in presentation. The neglected or chronically ruptured Achilles tendon presents a unique treatment challenge. The surgical approach varies greatly depending on the extent of degeneration and the resultant gap between the opposing tendon ends. Most surgeons have recommended the use of a tendon transfer or augmentation to strengthen the Achilles tendon repair. The following technique uses a flexor hallucis longus tendon transfer with gastrocnemius aponeurosis turndown flap augmentation. This technique has been commonly performed by us with success.

Daily versus three times weekly dosing for treatment of iron deficiency nonanemia in NCAA Division 1 female athletes.

OBJECTIVE: To compare the effectiveness, compliance, and side effect profile between daily or three times weekly (TIW) oral iron supplementation regimens in treating iron deficiency nonanemia (IDNA) in National Collegiate Athletic Association (NCAA) Division 1 female track and field or soccer athletes. DESIGN: Prospective cohort study. SETTING: Division 1 collegiate athletics. PARTICIPANTS: Thirty-three NCAA Division 1 female athletes (18 track and field, 15 soccer). INTERVENTIONS: Daily or TIW dosing of ferrous bisglycinate. MAIN OUTCOME MEASURES: Serum ferritin (µg/L) was measured before and after 8 weeks of supplementation. Self-reported compliance and side effect profile was assessed by electronic survey every 2 weeks. RESULTS: The average main effect for the TIW regimen was a significant increase of 5.17 µg/L (95% CI: 0.86-9.47) in serum ferritin (p = .02). The average main effect for the daily regimen was a significant increase of 12.88 µg/L (95% CI: 4.84-20.93) in serum ferritin (p = .003). The estimated average effect of the treatment on the treated between regimens was a nonsignificant decrease of -7.17 µg/L (95% CI: -19.02 - 3.59) in serum ferritin (p = .17). Thus, the TIW regimen increased serum ferritin 7.17 units less than the daily regimen on average after 8 weeks of supplementation. The athletes following the daily regimen experienced significantly more nausea (p = .04) and constipation (p = .002) compared to the TIW regimen. There was no statistical difference in compliance between the two groups (p = .14). CONCLUSIONS: Both the daily and TIW regimens increased serum ferritin. Compared to the daily regimen, the TIW regimen produced a smaller increase in serum ferritin but less nausea and constipation.

Thrombospondin-1, BIM and CFH polymorphisms and response to anti-VEGF treatment in neovascular age- related macular degeneration patients.

Age-related macular degeneration (AMD) is a vision threatening disease in older adults. Anti-VEGF treatment is effective for the majority of neovascular AMD (nAMD) patients, although approximately 30% of nAMD patients have an incomplete response for unknown reasons. Here we assessed the contribution of single nucleotide polymorphisms (SNPs) in key angioinflammatory regulatory genes in nAMD patients with an incomplete response compared to those responsive to anti-VEGF treatment. A total of 25 responsive and 30 nAMD patients with an incomplete response to anti-vascular endothelial growth factor (anti-VEGF) treatment were examined for known SNPs that impact the structure and function of thromobospondin-1 (TSP1), Bcl-2-interacting mediator of cell death (BIM) and complement factor H (CFH). Plasma levels of C-C motif chemokine ligand 2 (CCL2/MCP1), TSP1 and VEGF were assessed by ELISA. Patients responsive to anti-VEGF treatment showed a significant increase in the TSP1 rs2228262 AA allele and a trend for the BIM (rs724710) CT allele. Consistent with previous reports, 42% of the patients responsive to anti-VEGF expressed the CC allele for CFH rs1061170. Although the CFH TT allele had similarly low prevalence in both groups, the TC allele tended to be more prevalent in patients with an incomplete response. Patients with an incomplete response also had increased plasma CCL2/MCP1 levels, consistent with the role increased inflammation has in the pathogenesis of nAMD. Our studies point to new tools to assess the potential responsiveness of nAMD patients to anti-VEGF treatment and suggest the potential use of anti-CCL2 for treatment of nAMD patients with an incomplete response to anti-VEGF.

The Wisconsin silicone oil study (report #1): anatomical and functional outcomes of repair of retinal detachment with proliferative vitreoretinopathy.

BACKGROUND: Silicone oil (SO) is a long-term tamponade for repair of complex retinal pathology but has limitations including late redetachment. This study describes our experience with SO tamponade for repair of retinal detachment with proliferative vitreoretinopathy (PVR), with attention to anatomic and functional outcomes. METHODS: Retrospective consecutive case series of eyes with retinal detachment (RD) complicated by proliferative vitreoretinopathy (PVR) receiving SO tamponade at the University of Wisconsin between 2013 and 2019. Group 1 defined as primary SO placement; Group 2 had SO placed after failing prior retinal detachment repair. RESULTS: Inclusion criteria of SO placement for repair of RD with PVR was met for 117 eyes. The final reattachment rate was 84% for all eyes, with no difference between Groups 1 and 2. Vision improvement was 2.1 lines for Group 1 (p = 0.06 from baseline) and 4.6 lines for Group 2 (p < 0.0001). The mean number of silicone oil placements was 1.4. Less improvement in vision was noted with repeat SO placement, though overall functional vision of 5/200 or better was achieved in 63.2% of patients. CONCLUSIONS: SO tamponade allows long-term anatomical stabilisation and substantial vision recovery in eyes with retinal detachment complicated by PVR. Rates of anatomic and functional success have improved significantly when compared to prior studies using oil tamponade for repair of PVR.

Surgical approach for combined ankle and subtalar joint chronic mechanical instability.

Combined ankle and subtalar joint instability can lead to severe disability of the lower extremity. Multiple procedures have been described for hindfoot and ankle instability, including anatomic and non-anatomic reconstructions. The authors present their technique consisting of a free autogenous split peroneus longus tendon graft combined with a modified Brostrom-Gould repair.

The Ankle Joint: Non-Operative Updates in Ankle Arthritis, Are Biologics Working?

The vast majority of ankle arthritis is post-traumatic in nature, with rates of 60% to 80%. Symptoms include pain, decreased range of motion, and joint effusion. Diagnostic imaging is helpful in determining the degree of joint degeneration, with MRI and CT scan being the most sensitive. Conservative treatment modalities are targeted at reducing symptoms and improving function. Injectable therapy has gained popularity over the last few decades, with advancements in biologic treatments. Corticosteroids, hyaluronic acid, platelet-rich plasma, and amniotic tissue-derived products can be used to reduce inflammation in the joint, as well as prevent cartilage degeneration.

HNO and NO release from a primary amine-based diazeniumdiolate as a function of pH.

The growing evidence that nitroxyl (HNO) has a rich pharmacological potential that differs from that of nitric oxide (NO) has intensified interest in HNO donors. Recently, the diazeniumdiolate (NONOate) based on isopropylamine (IPA/NO; Na[(CH(3))(2)CHNH(N(O)NO)]) was demonstrated to function under physiological conditions as an organic analogue to the commonly used HNO donor Angeli's salt (Na(2)N(2)O(3)). The decomposition mechanism of Angeli's salt is dependent on pH, with transition from an HNO to an NO donor occurring abruptly near pH 3. Here, pH is shown to also affect product formation from IPA/NO. Chemical analysis of HNO and NO production led to refinement of an earlier, quantum mechanically based prediction of the pH-dependent decomposition mechanisms of primary amine NONOates such as IPA/NO. Under basic conditions, the amine proton of IPA/NO is able to initiate decomposition to HNO by tautomerization to the nitroso nitrogen (N(2)). At lower pH, protonation activates a competing pathway to NO production. At pH 8, the donor properties of IPA/NO and Angeli's salt are demonstrated to be comparable, suggesting that at or above this pH, IPA/NO is primarily an HNO donor. Below pH 5, NO is the major product, while IPA/NO functions as a dual donor of HNO and NO at intermediate pH. This pH-dependent variability in product formation may prove useful in examination of the chemistry of NO and HNO. Furthermore, primary amine NONOates may serve as a tunable class of nitrogen oxide donor.

Deep vein thrombosis after bunionectomy: a case report of two genetic mutations.

Deep venous thrombosis after foot and ankle surgery is a serious complication that can have potentially life-threatening complications, such as pulmonary embolus. Genetic mutations have been reported in the published data to cause an increased risk of developing deep vein thrombosis. Two such genetic mutations are the methylenetetrahydrofolate reductase gene variant C677T and the 4G/5G polymorphism of the plasminogen activator inhibitor gene. This case report presents a female patient who developed a postoperative deep vein thrombosis after hallux valgus reconstruction. A hypercoagulable panel revealed the 2 mentioned genetic mutations. We hope this case study will highlight the importance of ascertaining all patient risk factors and the relation to perioperative deep vein thrombosis prophylaxis.

Arthroscopic versus open ankle arthrodesis: a retrospective cost analysis.

Compared with traditional open arthrodesis, arthroscopic ankle arthrodesis has been associated with similar rates of fusion, decreased time to union, decreased pain, shorter hospital stay, earlier mobilization, reliable clinical results, and fewer complications. The aim of this case-control study was to analyze cost differences between outpatient arthroscopic and inpatient open ankle arthrodesis. To this end, the authors analyzed 20 ankle arthrodesis procedures: 10 performed by one surgeon on an inpatient basis using an open approach, and 10 performed by another surgeon on an outpatient basis arthroscopically. Patient age, body mass index, tourniquet time, length of stay, complications, days to clinical union, and insurance type, as well as charges and reimbursements for the surgeons and the hospital or surgery center were abstracted from the records. Statistically significant differences were observed between the outpatient arthroscopic and inpatient open arthrodesis groups for total site charges ($3898 +/- 0.00 versus $32,683 +/- $12,762, respectively, P < .0001), reimbursement to the surgeon ($1567 +/- $320 versus $1107 +/- $278, respectively, P = .003), and reimbursement to the hospital or ambulatory surgery center ($1110 +/- $287 versus $8432 +/- $2626, respectively); the ratio of hospital/surgery center charges to hospital/surgery center reimbursements was 28.48% for the inpatient arthroscopic group and 25.80% for the inpatient open arthrodesis group. Outpatient arthroscopic ankle arthrodesis, compared with inpatient open ankle arthrodesis, appears to be less expensive for third party payers, and surgeons are paid more, whereas hospitals and ambulatory surgical centers get paid a greater proportion of the charges that they bill.

Accuracy and Reproducibility Using Patient-Specific Instrumentation in Total Ankle Arthroplasty.

BACKGROUND: Implant survivorship is dependent on accuracy of implantation and successful soft tissue balancing. System instrumentation for total ankle arthroplasty implantation has a key influence on surgeon accuracy and reproducibility. The purpose of this study was to determine the accuracy and reproducibility of implant position with patient-specific guides for total ankle arthroplasty across multiple surgeons at multiple facilities. METHODS: This retrospective, multicenter study included 44 patients who received a total ankle implant (INBONE II Total Ankle System; Wright Medical Technology, Memphis, TN) using PROPHECY patient-specific guides from January 2012 to December 2014. Forty-four patients with an average age of 63.0 years underwent total ankle arthroplasty using this preoperative patient-specific system. Preoperative computed tomography (CT) scans were obtained to assess coronal plane deformity, assess mechanical and anatomic alignment, and build patient-specific guides that referenced bony anatomy. The mean preoperative coronal deformity was 4.6 ± 4.6 degrees (range, 14 degrees varus to 17 degrees valgus). The first postoperative weightbearing radiographs were used to measure coronal and sagittal alignment of the implant vs the anatomic axis of the tibia. RESULTS: In 79.5% of patients, the postoperative implant position of the tibia corresponded to the preoperative plan of the tibia within 3 degrees of the intended target, within 4 degrees in 88.6% of patients, and within 5 degrees in 100% of patients. The tibial component coronal size was correctly predicted in 98% of cases, whereas the talar component was correctly predicted in 80% of cases. CONCLUSION: The use of patient-specific instrumentation for total ankle arthroplasty provided reliable alignment and reproducibility in the clinical situation similar to that shown in cadaveric testing. This study has shown that the preoperative patient-specific instrumentation provided for accuracy and reproducibility of ankle arthroplasty implantation in a cohort across multiple surgeons and facilities. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Radiographic Assessment of a Medullary Total Ankle Prosthesis: A Test of Agreement and Reliability.

Total ankle replacement (TAR) is a viable alternative to ankle fusion in certain patients with end-stage ankle arthritis. Despite the importance of understanding alignment and movement of the prosthesis, there is no standardized radiographic method for evaluating the position and movement of the INBONE 2 prosthesis. The aims of this study were to describe a radiographic measurement protocol for INBONE 2 for clinical practice and research while determining the interobserver and intraobserver reliability using standard weightbearing radiographs. Fifteen patients were randomly selected with operative dates from January 2011 to January 2014 who underwent primary TAR using the INBONE 2 prosthesis. Most recent preoperative and first postoperative weightbearing anteroposterior and lateral radiographs were pulled and deidentified. Three foot and ankle surgeons blinded from the patient selection and deidentification, measured the described measurements on separate occasions. Intraobserver reliability: surgeon 1 had acceptable reliability for 9 of 13 continuous radiographic measurements (69.2%), surgeon 2 had acceptable reliability for 8 of 13 measurements (61.5%), and surgeon 3 had acceptable reliability for 12 of 13 measurements (92.3%). Interobserver reliability: among the first measurements, 6 of 13 continuous radiographic measurements (46.2%) had acceptable reliability. Among the second measurements, 7 of 13 measurements (53.8%) had acceptable reliability. Among the first and second measurements combined, 7 of 13 measurements (53.8%) had acceptable reliability. This study promotes the need for meticulous evaluation of annual radiographic findings following TAR in an effort to avoid catastrophic failure and represents moderate agreement can be obtained by employing the proposed measurements for surveillance of INBONE 2 TAR at annual postoperative visits. Measurements on the anteroposterior radiograph appear to demonstrate more consistent results for surveillance than lateral measurements. The intraobserver reliability results were somewhat superior to the interobserver reliability, implying more relevance for a single surgeon applying these measurements annually for postoperative surveillance. LEVELS OF EVIDENCE: Diagnostic, Level III.