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Undistorted monolayer graphene has energy bands which cross at protected Dirac points. It elastically deforms and much research has assumed the Dirac description persists, now in a curved space and coupled to a gauge field related to lattice strain. We show this is incorrect by using a real space gradient expansion to study how the Dirac equation derives from the tight binding model. Generic spatially varying hopping functions give rise to large magnetic fields which spoil the truncation in derivatives. In the perturbative regime, the only consistent truncation to Dirac is one with nontrivial gauge field but in flat space. One can instead fine tune the magnetic field to be small, and we derive the resulting differential condition that the hopping functions must satisfy to yield a consistent truncation to Dirac in curved space. We consider whether mechanical effects might impose this fine tuning, but find this is not the case for a simple elastic membrane model., v1. 5 pages; v2. journal version of article, text improvements and some discussion expanded, some references added, title changed to adhere to journal policy, 7 pages

Background Correction of talonavicular uncoverage (TNU) in adult-acquired flatfoot deformities (AAFD) can be a challenge. Lateral column lengthening (LCL) traditionally is utilized to address this. The primary study objective is examining stage II AAFD patients and determining if correction can be achieved with subtalar fusion (STF) comparable to LCL. Methods Following institutional review board approval, retrospective chart review performed identifying patients meeting criteria for stage IIB AAFD who underwent either STF with concomitant flatfoot procedures (but not LCL) to correct TNU, or who underwent LCL as part of their flatfoot reconstruction. Patients indicated for STF had one or more of the following: higher body mass index (BMI), were older, had greater deformity, lateral impingement pain, intraoperative spring ligament hyperlaxity. Patients without 1-year follow-up or compete records were excluded. All other patients were included. A total of 27 isolated STFs identified, along with 143 who underwent LCL. Pre-/postoperative radiographic parameters obtained as well as PROMIS (Patient-Reported Outcomes Measurement Information System) and FAOS (Foot and Ankle Outcome Score) scores. Radiographic and patient reported outcomes both preoperatively and at 1-year follow-up evaluated for both groups. Results STF patients were older ( P < .05), with higher BMIs ( P < .004). STF had significantly worse TNU ( P < .001) than LCL patients, and average change in STF TNU was larger than LCL change postoperatively ( P = .006), after adjusting for age, BMI, gender. PROMIS STF improvement reached statistical significance in Physical Function (P 0.011), for FAOS Pain (P 0.025) and Function ( P = 0.04). Conclusions STF can be used in appropriately indicated patients to correct flatfoot deformity without compromising radiographic or clinical, correcting not only hindfoot valgus, but also talonavicular uncoverage (TNU) and corresponding medial arch collapse. Levels of Evidence: Level III: Retrospective chart review comparison study (case control)

We construct a new class of supersymmetric $AdS_3\times Y_7$ solutions of type IIB supergravity, where $Y_7$ is an $S^5$ fibration over a spindle, which are dual to $d=2$, $\mathcal{N}=(0,2)$ SCFTs. The solutions are constructed in a sub-truncation of $D=5$, $SO(6)$ maximal gauged supergravity and they all lie within the anti-twist class. We show that the central charge computed from the gravity solutions agrees with an anomaly polynomial calculation associated with compactifying the $\mathcal{N}=1$, $d=4$ Leigh-Strassler SCFT on a spindle., Comment: 55 pages, 2 figures. Very minor changes - published version

Background: Arthrodesis of the first metatarsophalangeal (MTP) joint has been shown to be effective in alleviating pain and correcting deformity in hallux rigidus. However, outcomes in specific sports and physical activities remain unclear. The aim of this study was to assess sports and physical activities in young patients following first MTP joint arthrodesis and to compare these results with clinical outcomes. Methods: Patients between ages 18 and 55 years who underwent MTP arthrodesis were identified by review of a prospective registry. Fifty of 73 eligible patients (68%) were reached for follow-up at a mean of 5.1 (range, 2.2-10.2) years with a mean age at surgery of 49.7 (range, 23-55) years. Physical activity was evaluated with a previously developed sports-specific, patient-administered questionnaire. Clinical outcomes were evaluated with the Foot and Ankle Outcome Score (FAOS). Results: Patients participated in 22 different sports and physical activities. The most common were walking, biking, weightlifting, swimming, running, and golf. Compared to preoperatively, patients rated 27.4% of activities as less difficult, 51.2% as the same, and 21.4% as more difficult. Patients returned to 44.6% of preoperative physical activities in less than 6 months and reached their maximal level of participation in 88.6% of physical activities. Ninety-six percent of patients (48/50) were satisfied with the procedure regarding return to sports and physical activities. Improvements in the FAOS Symptoms subscore were associated with increased postoperative running and walking duration, and improvements in FAOS Pain subscores were associated with greater patient satisfaction. Conclusion: Patients were able to participate in a wide variety of sports and physical activities postoperatively. Some patients reported increased difficulty, but were nonetheless satisfied with the procedure regarding physical activity participation. These findings suggest that first MTP joint arthrodesis is a reasonable option in young, active patients, and may be used to guide postoperative expectations. Level of Evidence: Level IV, retrospective case series.

Missed fractures are the most common diagnostic error in emergency departments and can lead to treatment delays and long-term disability. Here we show through a multi-site study that a deep-learning system can accurately identify fractures throughout the adult musculoskeletal system. This approach may have the potential to reduce future diagnostic errors in radiograph interpretation.

BACKGROUND Neuraxial anesthesia is often viewed as superior to general anesthesia but may delay discharge. Comparisons do not typically use multimodal analgesics and nerve blockade. Combining nerve blockade with general anesthesia may reduce pain, opioid consumption, and nausea. We hypothesized that general anesthesia (with nerve blocks) would lead to earlier readiness for discharge, compared to spinal anesthesia (with nerve blocks). METHODS All patients underwent ambulatory foot and ankle surgery, with a predicted case duration of 1-3 hours. All patients received popliteal and adductor canal nerve blocks using bupivacaine and dexamethasone. No intraoperative opioids were administered. All patients received ondansetron, dexamethasone, ketamine, and ketorolac. Patients, data collectors, and the data analyst were not informed of group assignment. Patients were randomized to spinal or general anesthesia with concealed allocation. Spinal anesthesia was performed with mepivacaine and accompanied with propofol sedation. After general anesthesia was induced with propofol, a laryngeal mask airway was inserted, followed by sevoflurane and propofol. Time until ready for discharge, the primary outcome, was compared between groups after adjusting for age and surgery time using multivariable unconditional quantile regression. Secondary outcomes compared at multiple timepoints were adjusted for multiple comparisons using the Holm-Bonferroni step-down procedure. RESULTS General anesthesia patients were ready for discharge at a median of 39 minutes earlier (95% confidence interval, 2-75; P = .038) versus spinal anesthesia patients. Patients in both groups met readiness criteria for discharge substantially before actual discharge. Pain scores at rest were higher among general anesthesia patients 1 hour after leaving the operating room (adjusted difference in means, 2.1 [95% confidence interval, 1.0-3.2]; P < .001). Other secondary outcomes (including opioid use, opioid side effects, nausea, headache, sore throat, and back pain) were not different. CONCLUSIONS General anesthesia was associated with earlier readiness for discharge, but the difference may not be clinically significant and did not lead to earlier actual discharge. Most secondary outcomes were not different between groups. The choice of spinal or general anesthesia as an adjunct to peripheral nerve blockade can reflect patient, clinician, and institutional preferences.

We construct supersymmetric solutions of $D=11$ supergravity, preserving 1/4 of the supersymmetry, that are holographically dual to ABJM theory which has been deformed by spatially varying mass terms depending on one of the two spatial directions. We show that the BPS equations reduce to the Helmholtz equation on the complex plane leading to rich classes of new solutions. In particular, the construction gives rise to infinite classes of supersymmetric boomerang RG flows, as well as generalising a known Janus solution., Comment: 34 pages, 6 figures. Minor changes including a new analytic result on the refractive index. Version to be published

We consider real mass and FI deformations of ABJM theory preserving supersymmetry in the large N limit, and compare with holographic results. On the field theory side, the problems amounts to a spectral problem of a non-Hermitian Hamiltonian. For certain values of the deformation parameters this is invariant under an antiunitary operator (generalised $$ \mathcal{P}\mathcal{T} $$ P T symmetry), which ensures the partition function remains real and allows us to calculate the free energy using tools from statistical physics. The results obtained are compatible with previous work, the important new feature being that these are obtained directly from the real deformations, without analytic continuation.

Background: First metatarsophalangeal (MTP) joint arthrodesis is a common procedure for treatment of arthritis of the first MTP joint. The primary aim of this study was to evaluate the functional outcomes of a series of patients of multiple surgeons undergoing first MTP joint arthrodesis, emphasizing the functional gains with respect to daily activity that can be expected after this procedure. Methods: A retrospective review of 53 patients who underwent successful isolated first MTP joint arthrodesis with either a plate and screw or independent screw construct was performed at our institution over a 6-year period. Successful fusion was defined as no lucency at the first MTP joint and bridging of 2 or more cortices on the anteroposterior, lateral, and oblique radiographic views at final follow-up. Demographic information and radiographs were evaluated for all patients. Preoperative and postoperative Foot and Ankle Outcome Score (FAOS) and Short Form Health Status Survey (SF) 36/12 functional outcome scores, as well as responses from an activity- and footwear-specific questionnaire, were evaluated and compared between the 2 fixation methods. Fifty-three patients (56 feet) had radiographs showing successful fusions after being treated for advanced degenerative arthritis of the first MTP joint with arthrodesis. Average time to union was 5.4 months. Results: There was a significant reduction in difficulty in performing daily activities, with all subscales of the FAOS and the SF-12v2 significantly improving postoperatively ( P < .05). The majority of patients stated that their foot looked and felt better and were satisfied with the procedure. Five patients experienced painful hardware, which required removal. Conclusion: First MTP joint arthrodesis was successful in improving patient-reported outcomes, particularly the ability to perform daily activities. Most patients had little to no functional limitation and were satisfied with their outcome. The greatest functional improvements were seen in patients’ ability to walk distances and perform low-impact sport activity. Level of Evidence: Level III, retrospective comparative study.

The modified Lapidus procedure is widely used to correct hallux valgus but has been reported with high nonunion rates. In this study, we retrospectively reviewed the nonunion rate of the modified Lapidus procedure performed with rigid cross screw fixation, meticulous joint preparation, and shear-strain-relieved calcaneal bone graft.Does the performance of the Lapidus procedure with rigid cross screw fixation, complete joint preparation, and shear-strain-relieved calcaneal bone graft achieve higher union rates than currently reported? If nonunion does occur, what is the clinical course?We reviewed both radiographic and clinical results of the modified Lapidus procedure with the above technique in 171 patients (182 feet). Evaluation included age, gender, tobacco use, diabetic status, and radiographic analysis at least 3 months postoperatively.The modified Lapidus procedure described above resulted in a union rate of 97.3% (177 of 182 feet). Three of the five feet with radiographic nonunions were clinically symptomatic.The union rate of the modified Lapidus procedure is higher than previously reported when performed with rigid cross screw fixation, meticulous joint preparation, and shear-strain-relieved bone graft. Nonunion of the first tarsometatarsal joint should be considered an infrequent occurrence.

Background and Objectives Sciatic nerve block provides analgesia after foot and ankle surgery, but block duration may be insufficient. We hypothesized that perineural dexamethasone and buprenorphine would reduce pain scores at 24 hours. Methods Ninety patients received ultrasound-guided sciatic (25 mL 0.25% bupivacaine) and adductor canal (10 mL 0.25% bupivacaine) blockade, with random assignment into 3 groups (30 patients per group): control blocks + intravenous (IV) dexamethasone (4 mg) (control); control blocks + IV buprenorphine (150 μg) + IV dexamethasone (IV buprenorphine); and nerve blocks containing buprenorphine + dexamethasone (perineural). Patients received mepivacaine neuraxial anesthesia and postoperative oxycodone/acetaminophen, meloxicam, pregabalin, and ondansetron. Patients and assessors were blinded to group assignment. The primary outcome was pain with movement at 24 hours. Results There was no difference in pain with movement at 24 hours (median score, 0). However, the perineural group had longer block duration versus control (45.6 vs 30.0 hours). Perineural patients had lower scores for “worst pain” versus control (median, 0 vs 2). Both IV buprenorphine and perineural groups were less likely to use opioids on the day after surgery versus control (28.6%, 28.6%, and 60.7%, respectively). Nausea after IV buprenorphine (but not perineural buprenorphine) was severe, frequent, and bothersome. Conclusions Pain scores were very low at 24 hours after surgery in the context of multimodal analgesia and were not improved by additives. However, perineural buprenorphine and dexamethasone prolonged block duration, reduced the worst pain experienced, and reduced opioid use. Intravenous buprenorphine caused troubling nausea and vomiting. Future research is needed to confirm and extend these observations.

Background:The number of opioids prescribed and used has increased precipitously over the past 2 decades for a number of reasons and has led to increases in long-term dependency, opioid-related deaths, and diversion. Most studies examining the role of prescribing habits have investigated nonoperative providers, although there is some literature describing perioperative opioid prescription and use. There are no studies looking at the number of pills consumed after outpatient foot and ankle surgeries, nor are there guidelines for how many pills providers should prescribe. The purpose of this study was to quantify the number of narcotic pills taken by opioid-naïve patients undergoing outpatient foot and ankle surgeries with regional anesthesia.Methods:Eighty-four patients underwent outpatient foot and ankle surgeries under spinal blockade and long-acting popliteal blocks. Patients were given 40 or 60 narcotic pills, a 3-day supply of ibuprofen, deep vein thrombosis prophylaxis, and antiemetics. Patients received surveys at postoperative day (POD) 3, 7, 14, and 56 documenting if they were still taking narcotics, the quantity of pills consumed, whether refills were obtained, their pain level, and their reason for stopping opioids.Results:Patients consumed a mean of 22.5 pills, with a 95% confidence interval from 18 to 27 pills. Numerical Rating Scale pain scores started at 4 on POD 3 and decreased to 1.8 by POD 56. The percentage of patients still taking narcotics decreased from 55% on POD 3 to 2.8% by POD 56. Five new prescriptions were given during the study, with 3 being due to side effects from the original medication.Conclusions:Patients receiving regional anesthesia for outpatient foot and ankle surgeries reported progressively lower pain scores with low narcotic use up to 56 days postoperatively. We suggest that providers consider prescribing 30 pills as the benchmark for this patient population.Level of Evidence:Level II, prospective comparative study.

Background:Autogenous bone grafting is commonly used as an adjuvant in foot and ankle procedures. The iliac crest and tibia are common sources of autogenous bone graft but require a separate operative site and have been reported to have significant morbidity including pain, fractures, and prolonged hospitalization. Bone grafting from the posterolateral calcaneus offers advantages such as a single operative field, ability to be done under an ankle block, and a theoretical low complication rate. We report our morbidity and complications of percutaneous calcaneal autograft bone harvest in patients undergoing foot operations.Methods:Between 2006 and 2010, 6 foot and ankle surgeons performed a calcaneal bone graft on 393 patients undergoing foot procedures. Outcomes were measured through the use of a 4-question survey evaluating pain, subjective sensitivity at the incision site, numbness at the incision site, and limitation of shoe wear at a minimum of 1 year following the operation. Patient records were also examined for any additional complications that may have been reported.Results:Of the 393 patients eligible for this study, 210 patients responded at an average of 2.8 years (range, 1.2-5.8 years) after the operation (minimum 1 year). Of those, 181 patients (86.2%) reported no problems. Minor complications included 6 patients (2.9%) who experienced only incisional nerve sensitivity, 4 patients (1.9%) with only incisional pain, 4 patients (1.9%) who reported some degree of incisional numbness only, 2 patients (1.0%) who reported only shoe wear limitations, and 10 patients (4.8%) who had a combination of symptoms. Three patients (1.4%) had more significant complications, which consisted of a pathological fracture through the graft site, a calcaneal stress fracture, and 1 patient with permanent numbness along the distribution of the sural nerve.Conclusion:Calcaneal bone graft was an easily accessible source of local autogenous bone graft for foot and ankle procedures. Despite the simplicity of the procedure, minor complications are not infrequent, with 13.8% of patients reporting some residual symptoms along the lateral border of the calcaneus when bone graft was obtained through an oblique incision.Level of Evidence:Level IV, case series.

Lateral column lengthening (LCL) is used to address the forefoot abduction associated with the adult acquired flatfoot. This opening wedge osteotomy can be filled with either allograft or autograft bone.The investigators sought to determine union rates and any loss of correction in patients undergoing LCL with autograft versus allograft.Over a 3-year period, 126 LCLs performed by five surgeons in 120 patients were reviewed. Autograft was used in 51 patients, allograft in 75 patients. Times to clinical and radiographic union were established for these patients. Any loss of correction of forefoot abduction as manifested by talonavicular uncoverage was recorded for those grafts that healed. Failure was defined as nonunion or loss of 50% or greater correction. The size of the implanted graft was assessed as a risk factor for failure.There were 20 total failures: seven in patients with autograft and 13 in patients with allograft (p = 0.63). The size of the implanted graft was larger in those patients that did fail (p = 0.04).The rate of nonunion and loss of correction for LCL was not significantly different between allograft and autograft. The overall rate of nonunion may be higher than has previously been reported.

Background: Many authors have reported on patient satisfaction from foot and ankle surgery, but rarely on expectations, which may vary widely between patients and strongly affect satisfaction. In this study, we aimed to develop a patient-derived survey on expectations from foot and ankle surgery. Methods: We developed and tested our survey using a 3-phase process. Patients with a wide spectrum of foot and ankle diagnoses were enrolled. In phase 1, patients were interviewed preoperatively with open-ended questions about their expectations from surgery. Major concepts were grouped into categories that were used to form a draft survey. In phase 2, the survey was administered to preoperative patients on 2 occasions to establish test-retest reliability. In phase 3, the final survey items were selected based on weighted kappa values for response concordance and clinical relevance. Results: In phase 1, 94 preoperative patients volunteered 655 expectations. Twenty-nine representative categories were discerned by qualitative analysis and became the draft survey. In phase 2, another 60 patients completed the draft survey twice preoperatively. In phase 3, 23 items were retained for the final survey. For retained items, the average weighted kappa value was 0.54. An overall score was calculated based on the amount of improvement expected for each item on the survey and ranged from zero to 100, with higher scores indicating more expectations. For patients in phase 2, mean scores for both administrations were 65 and 66 and approximated normal distributions. The intraclass correlation coefficient between scores was 0.78. Conclusion: We developed a patient-derived survey specific to foot and ankle surgery that is valid, reliable, applicable to diverse diagnoses, and includes physical and psychological expectations. The survey generates an overall score that is easy to calculate and interpret, and thus offers a practical and comprehensive way to record patients’ expectations. We believe this survey may be used preoperatively by surgeons to help guide patients’ expectations and facilitate shared decision making. Level of Evidence: Level II, cross-sectional study.

Fractional quantum Hall liquids exhibit a rich set of excitations, the lowest-energy of which are the magnetorotons with dispersion minima at a finite momentum. We propose a theory of the magnetorotons on the quantum Hall plateaux near half filling, namely, at filling fractions $\nu=N/(2N+1)$ at large $N$. The theory involves an infinite number of bosonic fields arising from bosonizing the fluctuations of the shape of the composite Fermi surface. At zero momentum there are $O(N)$ neutral excitations, each carrying a well-defined spin that runs integer values $2,3,\ldots$. The mixing of modes at nonzero momentum $q$ leads to the characteristic bending down of the lowest excitation and the appearance of the magnetoroton minima. A purely algebraic argument shows that the magnetoroton minima are located at $q\ell_B=z_i/(2N+1)$, where $\ell_B$ is the magnetic length and $z_i$ are the zeros of the Bessel function $J_1$, independent of the microscopic details. We argue that these minima are universal features of any two-dimensional Fermi surface coupled to a gauge field in a small background magnetic field., Comment: 5 pages, 2 figures; v3: published version

Background: Research regarding outcomes in sports and physical activities after primary partial arthrodesis for Lisfranc injuries has been sparse. The purposes of this study were to assess various sports and physical activities in young patients following primary partial arthrodesis for Lisfranc injuries and to compare these with clinical outcomes. Methods: Patients who underwent primary partial arthrodesis for a Lisfranc injury were identified by a retrospective registry review. Thirty-eight of 46 eligible patients (83%) responded for follow-up at a mean of 5.2 (range, 1.0 to 9.3) years with a mean age at surgery of 31.8 (range, 16.8 to 50.3) years. Physical activity participation was assessed with a new sports-specific, patient-administered questionnaire. Clinical outcomes were assessed with the Foot and Ankle Outcome Score (FAOS). Results: Patients participated in 29 different and 155 total physical activities preoperatively, and 27 different and 145 total physical activities postoperatively. Preoperatively, 47.1% were high impact, and postoperatively, 44.8% were high impact. The most common activities were walking, bicycling, running, and weightlifting. Compared to preoperatively, difficulty was the same in 66% and increased in 34% of physical activities. Participation levels were improved in 11%, the same in 64%, and impaired in 25% of physical activities. Patients spent on average 4.2 (range, 0.0 to 19.8) hours per week exercising postoperatively. In regard to return to physical activity, 97% of respondents were satisfied with their operative outcome. Mean postoperative FAOS subscores were significantly worse for patients who had increased physical activity difficulty. Conclusion: Most patients were able to return to their previous physical activities following primary partial arthrodesis for a Lisfranc injury, many of which were high-impact. However, the decreased participation or increase in difficulty of some activities suggests that some patients experienced postoperative limitations in exercise. Future studies could compare sports outcomes between primary partial arthrodesis and open reduction internal fixation for Lisfranc injuries. Level of Evidence: Level IV, retrospective case series.

Background: The modified Lapidus procedure has successfully relieved pain and corrected deformity in patients with hallux valgus, but its effect on participation in specific sports and physical activities remains unclear. Our goals were to assess sports and physical activities in young patients following the modified Lapidus procedure and to compare these with clinical outcomes. Methods: Fifty-eight eligible patients were identified from a retrospective registry review. Of these, 48 (83%) were reached for follow-up at a mean of 2.8 (range, 1.0 to 6.1) years and had a mean age at surgery of 37.3 (range, 14.1 to 49.3) years. Physical activity participation was evaluated with a new sports-specific, patient-administered questionnaire. Clinical outcomes were evaluated with the Foot and Ankle Outcome Score (FAOS) and compared to sports outcomes. Results: Patients participated in 26 different physical activities, consisting of 212 total physical activities preoperatively and 209 total postoperatively. The most common were walking, running, bicycling, and swimming. Compared to preoperatively, patients rated 29% of activities as less difficult, 52% as the same, and 19% as more difficult and rated participation levels as improved in 40%, the same in 41%, and impaired in 19%. Eighty-one percent of patients were satisfied with their operative outcome in regard to return to physical activity. Changes in the FAOS Pain subscore were significantly associated with improvements in physical activity difficulty ( P < .05), and changes in the Pain, Sports, and QOL subscores were significantly associated with changes in physical activity participation levels ( P < .05). Conclusion: Four in 5 patients were able to participate in previous sports and physical activities, including high-impact activities, at their preoperative participation level or better after the modified Lapidus procedure, and were satisfied with surgery in regard to return to previous activity. However, several patients had increased difficulty and impaired participation in physical activity postoperatively. Altogether, this suggests that the procedure is a viable treatment option for hallux valgus in young, active patients. Level of Evidence: Level IV, retrospective case series.

Category: Other Introduction/Purpose: Neuraxial anesthesia is often viewed as superior to general anesthesia (GA), but there are concerns that it may prolong length of stay (LOS). Most studies comparing the two anesthesias were performed in the absence of peripheral nerve blocks (PNBs), which when used as an analgesic adjunct may overcome the associated negative side effects of GA and allow decreased LOS. We hypothesized that patients given PNBs and GA would be discharged sooner than patients given PNBs and spinal anesthesia plus sedation, without increased incidence of adverse side effects such as pain, opioid administration and nausea. Methods: A single-center triple-blinded randomized controlled trial of 36 consecutive patients receiving elective F&A surgery predicted to take 1-3 hours under planned PNB with either spinal or GA was performed (see table 1. for demographics).The primary outcome was time to meet criteria for home discharge. The a priori clinically relevant difference with 80% power was determined to be 45 minutes. Patients were assessed after admission to the PACU and at 15-minute intervals thereafter. Once an Aldrete score=9 (scale signifying patient no longer needs intensive monitoring) was obtained, patients were transferred to Phase II and assessed until the post anesthesia discharge scoring system, a home readiness scale, was =9. Actual time to discharge was also recorded.Additional outcomes included a series of baseline characterizations which were assessed pre-and post-operatively, and again during Phase II.The primary outcome was compared using multivariable unconditional quantile regression. Various regressions were performed on secondary outcomes. Results: After adjustment for age and surgical duration, patients given GA plus PNB were ready for discharge from PACU 39 minutes prior to patients given neuraxial anesthesia plus PNB, but this difference did not reach the clinically relevant a priori selected difference of 45 minutes (Table 1). However, the adjusted median time to meet ambulation discharge criteria was 52 minutes fewer (p = 0.003) (Table 1). Patients met discharge criteria substantially sooner than their time until actual discharge which was not different between groups (Table 1). Pain scores at rest were higher among GA patients at 1 hour in the PACU (adjusted difference in means [95% CI]: 2.1 [1.0, 3.2], p < 0.001). Subsequent pain scores and all other secondary outcomes were not different. Conclusion: GA with PNB patients were ready for discharge 39 minutes earlier, but that difference may not be clinically significant. Although patients met criteria for discharge sooner due to a significantly more rapid ability to ambulate, they were not discharged sooner because PACU staff was not acclimated to the earlier readiness and so did not push for earlier discharge. These findings suggest that GA plus PNB leads to earlier discharge with similar side effects as spinal plus PNB. Therefore, the use of GA with PNB for foot and ankle surgeries could save the hospital and the patient time and resources.

Background: In 2003, a limited survey regarding the number of dedicated foot and ankle faculty and foot and ankle rotations at orthopaedic surgery residency programs was published. The purpose of this paper was to update the results of that previous survey and provide additional, more in-depth information. Materials and Methods: A survey questionnaire was emailed to the program directors and chairpersons of the 150 ACGME-accredited orthopaedic residency training programs in the United States. Results: Responses were obtained from all programs. One hundred thirty-seven (91.3%) programs had one or more orthopaedic surgeon faculty members with a predominantly foot and ankle practice (at least 50%), an increase of 5.5 percentage points from the survey performed 6 years previously. One hundred forty three (95.3%) programs had one or more orthopaedic surgeon faculty members with a practice consisting of at least 25% foot and ankle. One hundred twenty programs (80%) had one or more dedicated foot and ankle rotations, an increase of 15.1% from 6 years prior. Orthopaedic surgery residents were felt to spend a mean of 30.4% and a median of 20% of their time with board-certified/ board-eligible orthopaedic surgeons in rotations that include treatment of foot and ankle pathology but were not considered “dedicated” foot and ankle rotations. Conclusions: The number of orthopaedic surgery residency programs with rotations and faculty members dedicated to foot and ankle education has increased over the 6 years between surveys. Orthopaedic surgery residents’ experience and skill development in foot and ankle surgery during their 5 years of residency training are not limited to their time spent in dedicated foot and ankle rotations.

Category: Other Introduction/Purpose: Few authors have investigated patients’ expectations from foot and ankle surgery, and standardized means of assessing expectations are lacking. Managing patients’ preoperative expectations may help improve their ultimate satisfaction with surgery. In a previous study (in press), we developed a valid and reliable patient-derived expectations survey for patients undergoing foot and ankle surgery. In this study, we aimed to examine relationships between patients’ preoperative expectations and their demographic and clinical characteristics. We hypothesized that patients with more disability and those with anxiety or depressive symptoms would have greater expectations. Methods: All adult patients scheduled for elective foot or ankle surgery by one of six orthopaedic foot and ankle surgeons were screened for inclusion over eight months. Preoperatively, patients completed the Foot & Ankle Surgery Expectations Survey in addition to the Foot & Ankle Outcome Score (FAOS), Short Form (SF)-12, Patient Health Questionnaire (PHQ)-8, Generalized Anxiety Disorder 7-item scale (GAD-7), and pain visual analog scale (VAS). The expectations survey contains 23 expectations categories, each with five answer choices ranging from I do not have this expectation to complete improvement expected. It is scored from 0-100; higher scores indicate greater expectations. Differences in expectations score with categorical variables were assessed with t-tests and single factor analysis of variance (ANOVA). Differences in number of expectations and number of expectations with complete improvement expected were assessed with Mann-Whitney U and Kruskal Wallis tests. Relationships between expectations and continuous variables were assessed with linear regression. Results: 352 patients (average age 55 ± 15, range 18 to 86) were enrolled. Expectations were not significantly related to age. Women expected to achieve complete improvement more often than men (p = 0.011). Other factors significantly associated with higher expectations (p < 0.05) included non-Caucasian race, workers’ compensation, use of a cane or other assistive device, diagnosis of ankle instability or osteochondral lesion, and greater medical comorbidity (Table). Patients with a history of prior orthopaedic surgery were less likely to expect complete improvement. Worse function and quality of life (as assessed by all FAOS subscales and SF-12 physical and mental components), more depressive and anxiety symptoms, and higher pain VAS scores were associated with higher expectations scores and more expectations (p < 0.001 for all). Conclusion: The results of this study may help inform surgeons’ preoperative discussions with their patients regarding realistic expectations from surgery. Generally patients with worse function and more disability had higher expectations from surgery. Addressing these patients’ expectations preoperatively may help improve their ultimate satisfaction with surgery.

Background: Heightened security concerns have made metal detectors a standard security measure in many locations. While prior studies have investigated the detection rates of various hip and knee implants, none have looked specifically at the detection of foot and ankle implants in an in vivo model. Our goals were to identify which commonly used foot and ankle implants would be detected by walkthrough metal detectors both in vivo and ex vivo. Methods: Over a 7-month period, 153 weightbearing patients with foot and ankle hardware were recruited to walk through a standard airport metal detector at 3 different program settings (buildings, airports, and airports enhanced) with a base sensitivity of 165 (arbitrary units), as currently used by the Transportation Security Administration. The number of implants, location and type, as well as the presence of concomitant hardware outside of the foot and ankle were recorded. To determine the detection rate of common foot and ankle implants ex vivo, different hardware sets were walked through the detector at all 3 program settings. Results: Seventeen patients were found to have detectable hardware at the buildings, airports, and airports enhanced settings. An additional 3 patients had hardware only detected at the airports enhanced setting. All 20 of these patients had concomitant metal implants outside of the foot and ankle from other orthopaedic procedures. All patients with foot and ankle implants alone passed through undetected. Seven hardware sets were detected ex vivo at the airports enhanced setting. Conclusion: Our results indicate that patients with foot and ankle implants alone are unlikely to be detected by walkthrough metal detectors at standard airport settings. When additional hardware is present from orthopaedic procedures outside of the foot and ankle, metal detection rates were higher. We believe that these results are important for surgeons in order to educate patients on how they might be affected when walking through a metal detector such as while traveling. Level of Evidence: Level II, prospective comparative study.

Background: Arthritis and other rheumatic conditions are the leading causes of disability among adults in the United States. The purpose of this report was to describe the self-reported functional limitations of a group of patients with end-stage ankle arthrosis. Method: Patients who presented for operative management of end-stage ankle arthrosis at the University of Minnesota and Harborview Medical Center completed a Musculoskeletal Functional Assessment (MFA) as part of their preoperative clinical evaluation. Data from patients evaluated during the time period April, 1995, through May, 2004, were used for this project. Results: Four hundred and twenty-six patients with the diagnosis of end-stage ankle arthrosis completed baseline questionnaires. Six of the 426 patients received care on both ankles during the time of this project. The average age of patients at the time of completion of the questionnaire was 56.7 years. There were 241 men and 185 women. The primary underlying causes identified by the treating surgeon at the time of surgery were primary osteoarthritis with no known prior trauma (66), previous trauma (tibial fracture, foot fractures, or ankle ligamentous disruption) (296), rheumatoid arthritis (24), no known cause (21), and a variety of diseases or infections (19). In all domains, the patients with end-stage ankle arthrosis showed statistically significant differences from a general population sample. Conclusions: The effects of ankle arthritis as demonstrated by this data are severe. Most of these patients were severely limited in function. Without a data-driven understanding of the limitations the patients have, it is difficult to make an effective argument for focused research to solve the problems. Without understanding the patients' needs, it is impossible to assess the effect of treatment. The information in this paper provides a baseline understanding of effect of the current functional limitations of patients with end-stage ankle arthrosis.

We compute the sub-leading terms in the Tian-Yau-Zelditch asymptotic expansion of the partition function for dual giant gravitons on AdS 5 × L 5 and provide a bulk interpretation in terms of curvature invariants. We accomplish this by relating the partition function of dual giant gravitons to the Hilbert series for mesonic operators in the CFT. The coefficients of the subleading terms encode integrated curvature invariants of L 5. In the same spirit of Martelli, Sparks and Yau, we are able to compute these integrated curvature invariants without explicit knowledge of the Sasaki-Einstein metric on L 5. These curvature invariants contribute to the 1/N 2 corrections of the difference of the 4D anomaly coefficients a and c recently found by Liu and Minasian, which we now have a purely field theoretic method of calculating.

Background:The incidence of Achilles rupture appears to be less in women, although this notion has not been specifically investigated in the literature.Methods:The medical records of 7 foot-and-ankle orthopaedic surgeons at 1 institution were reviewed by Current Procedural Terminology (code 27650) and International Classification of Diseases–9 (code 727.67) to establish all Achilles tendon ruptures seen and/or treated by these surgeons. Sex, age, side, and mechanism of injury were recorded. Whether the patient had an acute Achilles tendon rupture or nonacute Achilles pathology was also noted.Results:A total of 468 patients were identified, of whom 358 had acute ruptures: 302 male and 56 female (5.39:1). Patients with acute ruptures were significantly younger than those with nonacute pathology (43.8 vs 55.1, P < .001). For acute ruptures, the mean age was not significantly different between men and women (43.9 vs 43.2; P = .780). Athletic activity was causative in 243 of 302 men (80.5%) and in 40 of 56 women (71.4%). This difference was not statistically significant ( P = .130). Six men (2.0%) and 6 women (10.7%) had comorbidities that were thought to increase their risk of rupture ( P = .005).Conclusion:Achilles tendon rupture is more common in men than women. Previous studies using the aforementioned codes to identify patients without chart review may have overestimated the number of women with acute Achilles tendon rupture.Level of Evidence:Level III, retrospective comparative series.

Category: Sports. Introduction/Purpose: The purpose of this paper is to both refute and condemn the current practice of open reduction and internal fixation in the treatment of both uncomplicated partial and complete tarsal navicular stress fractures. It will deal with issues that have violated the basic principals of clinical based evidence and resulted in unnecessary surgery, patient injury, and excessive costs. Methods: Ten cases managed by the senor author as well as a meta-analysis 250 cases in 19 published reports in the peer reviewed literature will be reported vis-a- vis surgical vs. conservative management. Management of the dorsal transverse fragment will be discussed, The large cost disparity between operative and non-operative management will be emphasized. The vascular and biomechanical factors will be presented. Results: The 10 cases of TNSF reported & treated by the senior author successfully healed by non-surgical, non-weight management. The meta-analysis of 250 reported cases treated conservatively had 96% successful outcomes. Conversely, those cases treated surgically with screw fixation had a 19% to 26% failure / major complication rates with repeat surgery and some with years of disability, Conclusion: Surgical management of TNSFs has resulted in a 19% to 26% non-union +/or morbidity rate, a marked increase in costs and is contra-indicated in the management of all non-displaced lesions. Non-weight bearing immobilization is indicated for both partial and complete sagittal fractures. Treatment should be based on established evidence based data and not on economic or remuneration factors. Orthopedic surgeons should subscribe to the concept of self regulation in dealing with this situation.

Background and Objectives Pregabalin is often used as a perioperative analgesic adjunct; some studies show benefit, but others do not. Adverse effects, such as confusion and sedation, have been attributed to perioperative use of pregabalin. We tested the hypothesis that pregabalin, when used as part of a multimodal analgesic regimen, reduces the duration of moderate to severe pain in the first 24 hrs following foot or ankle surgery. Secondary outcomes included measures of opioid and pregabalin adverse effects. Methods Sixty patients scheduled for hospital admission after foot or ankle surgery entered this randomized, double-blind, placebo-controlled trial. Patients received a neuraxial anesthetic, a popliteal fossa sciatic nerve block using 30 mL 0.375% bupivacaine with clonidine 100 µg and epinephrine, a saphenous nerve block, postoperative hydromorphone intravenous patient-controlled analgesia, and oral analgesics (oxycodone/acetaminophen). Patients were randomized to receive pregabalin (100 mg preoperatively, then 50 mg every 12 hrs) or a placebo for 3 days. The primary outcome was the number of hours that patients reported moderate to severe pain. Results Both groups reported a similar number of hours of moderate to severe pain during the first 24 hrs: 4.1 (SD, 4.1) hrs (pregabalin) versus 4.5 (SD, 3.5) hrs (placebo). Pain scores, opioid use, and adverse effects were also similar in both groups. Conclusions No clinical benefit was obtained from perioperative administration of pregabalin (100 mg preoperative, then 50 mg every 12 hrs) as part of a multimodal postoperative analgesic regimen following foot and ankle surgery.

Background: The optimal method of treatment for Lisfranc fracture-dislocations remains controversial, and the role of primary partial arthrodesis for combined osseous-ligamentous Lisfranc injuries is unclear. This study reviewed the outcomes of Lisfranc injuries treated by primary partial arthrodesis. Methods: Patients who underwent primary partial arthrodesis for a primarily ligamentous or combined osseous and ligamentous Lisfranc fracture-dislocation were reviewed retrospectively and assessed at followup according to radiographic, clinical and standardized patient-based outcomes. Twenty-five patients (12 ligamentous, 13 combined), median age of 46 (range, 20 to 73) years, were followed for an average of 42 (range, 24 to 96) months. Results: The average American Orthopedic Foot and Ankle Society (AOFAS) score was 81 points (scale 0 to 100), with patients in general losing points for mild pain, limitations of recreational activities, and fashionable footwear requirements. There was no statistical difference between ligamentous and combined injuries with regard to the physical or mental component scores on the SF-36. At latest followup, patients reported an average return to 85% of their preinjury activity level (range, 50% to 100%). Twenty-one patients (84%) expressed satisfaction with their outcome and at latest followup, the mean visual analog pain scale (VAS) score was 1.8 out of 10 (range, 0 to 8). Three patients showed radiographic signs of posttraumatic arthritis of adjacent joints. Conclusion: Treatment of both primarily ligamentous and combined osseous and ligamentous lisfranc injuries with primary partial arthrodesis produced good clinical and patient-based outcomes.Level of Evidence: III, Retrospective Comparative Study

We investigate the non-perturbative stability of asymptotically anti-de Sitter gravity coupled to tachyonic scalar fields with mass saturating the Breitenlohner-Freedman bound. Such "designer gravity" theories admit a large class of boundary conditions at asymptotic infinity. At this mass, the asymptotic behavior of the scalar field develops a logarithmic branch, and previous attempts at proving a minimum energy theorem failed due to a large radius divergence in the spinor charge. In this paper, we finally resolve this issue and derive a lower bound on the conserved energy. Just as for masses slightly above the BF bound, a given scalar potential can admit two possible branches of the corresponding superpotential, one analytic and one non-analytic. The key point again is that existence of the non-analytic branch is necessary for the energy bound to hold. We discuss several AdS/CFT applications of this result, including the use of double-trace deformations to induce spontaneous symmetry breaking., Comment: 31 pages, 7 figures

The low energy field theory for N type IIA D4-branes at strong 't Hooft coupling, wrapped on a circle with antiperiodic boundary conditions for fermions, is known to have a vacuum energy which depends on the $\theta$ angle for the gauge fields, and which is a multivalued function of this angle. This gives a field-theoretic realization of "axion monodromy" for a nondynamical axion. We construct the supergravity solution dual to the field theory in the metastable state which is the adiabatic continuation of the vacuum to large values of $\theta$. We compute the energy of this state and show that it initially rises quadratically and then flattens out. We show that the glueball mass decreases with $\theta$, becoming much lower than the 5d KK scale governing the UV completion of this model. We construct two different classes of domain walls interpolating between adjacent vacua. We identify a number of instability modes -- nucleation of domain walls, bulk Casimir forces, and condensation of tachyonic winding modes in the bulk -- which indicate that the metastable branch eventually becomes unstable. Finally, we discuss two phenomena which can arise when the axion is dynamical; axion-driven inflation, and axion strings., Comment: 43 pages, 10 figures. v2: references updated

Recently proposed "critical" higher-derivative gravities in $AdS_D$ $D>3$ are expected to carry logarithmic representation of the Anti de Sitter isometry group. In this note, we quantize linear fluctuations of these critical gravities, which are known to be either identical with linear fluctuations of Einstein's gravity or else satisfy logarithmic boundary conditions at spacial infinity. We identify the scalar product uniquely defined by the symplectic structure implied by the classical action, and show that it does not posses null vectors. Instead, we show that the scalar product between any two Einstein modes vanishes, while the scalar product of an Einstein mode with a logarithmic mode is generically nonzero. This is the basic property of logarithmic representation that makes them neither unitary nor unitarizable., v2: typos corrected and slight clarifications. 11 pages

Motivated by the Kerr/CFT conjecture, we explore solutions of vacuum general relativity whose asymptotic behavior agrees with that of the extremal Kerr throat, sometimes called the Near-Horizon Extreme Kerr (NHEK) geometry. We argue that all such solutions are diffeomorphic to the NHEK geometry itself. The logic proceeds in two steps. We first argue that certain charges must vanish at all times for any solution with NHEK asymptotics. We then analyze these charges in detail for linearized solutions. Though one can choose the relevant charges to vanish at any initial time, these charges are not conserved. As a result, requiring the charges to vanish at all times is a much stronger condition. We argue that all solutions satisfying this condition are diffeomorphic to the NHEK metric., Comment: 42 pages, 3 figures. v3: minor clarifications and corrections

The recently-conjectured Kerr/CFT correspondence posits a field theory dual to dynamics in the near-horizon region of an extreme Kerr black hole with certain boundary conditions. We construct a boundary stress tensor for this theory via covariant phase space techniques. The structure of the stress tensor indicates that any dual theory is a discrete light cone quantum theory, in agreement with recent arguments by Balasubramanian et al. The key technical step in our construction is the addition of an appropriate counter-term to the symplectic structure, which is necessary to make the theory fully covariant and to resolve a subtle problem involving the integrability of charges., Comment: 19 pages

We prove that the only four dimensional, stationary, rotating, asymptotically flat (analytic) vacuum black hole with a single degenerate horizon is given by the extremal Kerr solution. We also prove a similar uniqueness theorem for the extremal Kerr-Newman solution. This closes a longstanding gap in the black hole uniqueness theorems., Comment: 12 pages, v2: important references to earlier work added, v3: minor clarifications

We extend earlier treatments of holographic superconductors by studying cases where operators of different dimension condense in both 2+1 and 3+1 superconductors. We also compute a correlation length. We find surprising regularities in quantities such as $\omega_g/T_c$ where $\omega_g$ is the gap in the frequency dependent conductivity. In special cases, new bound states arise corresponding to vector normal modes of the dual near-extremal black holes., Comment: 17 pages, 6 figures. v2: minor typos corrected

We show that an extremal Kerr black hole, appropriately lifted to M theory, can be transformed to a Kaluza-Klein black hole in M theory, or a D0-D6 charged black hole in string theory. Since all the microstates of the latter have recently been identified, one can exactly reproduce the entropy of an extremal Kerr black hole. We also show that the topology of the event horizon is not well defined in M theory.

We present the case of a patient with bilateral Galeazzi fracture-dislocations with an irreducible distal radioulnar joint (DRUJ) on one side. Current treatments, such as anatomic reduction and stable internal fixation of the radius and anatomic and stable reduction of the DRUJ followed by plaster immobilization in supination, have produced results much better than those associated with historical conservative treatments. The most important part of successful treatment is maintaining intraoperative control of reduction quality, DRUJ stability, and, if necessary, open reduction of the DRUJ. Here we describe the surgical technique and present the rare case of a DRUJ being irreducible because of interposition of the extensor carpi ulnaris tendon.

Entanglement (Renyi) entropies of spatial regions are a useful tool for characterizing the ground states of quantum field theories. In this paper we investigate the extent to which these are universal quantities for a given theory, and to which they distinguish different theories, by comparing the entanglement spectra of the massless Dirac fermion and the compact free boson in two dimensions. We show that the calculation of Renyi entropies via the replica trick for any orbifold theory includes a sum over orbifold twists on all cycles. In a modular-invariant theory of fermions, this amounts to a sum over spin structures. The result is that the Renyi entropies respect the standard Bose-Fermi duality. Next, we investigate the entanglement spectrum for the Dirac fermion without a sum over spin structures, and for the compact boson at the self-dual radius. These are not equivalent theories; nonetheless, we find that (1) their second Renyi entropies agree for any number of intervals, (2) their full entanglement spectra agree for two intervals, and (3) the spectrum generically disagrees otherwise. These results follow from the equality of the partition functions of the two theories on any Riemann surface with imaginary period matrix. We also exhibit a map between the operators of the theories that preserves scaling dimensions (but not spins), as well as OPEs and correlators of operators placed on the real line. All of these coincidences can be traced to the fact that the momentum lattice for the bosonized fermion is related to that of the self-dual boson by a 45 degree rotation that mixes left- and right-movers., 40 pages; v3: improvements to presentation, new section discussing entanglement negativity

Gastrocnemius tightness is commonly found in patients with foot/ankle dysfunction. Gastrocnemius lengthening or recession is commonly performed as part of the treatment for plantar fasciitis, hallux valgus, symptomatic adult acquired flatfoot, metatarsalgia, and/or diabetic foot ulcers. We describe a technique using a vaginal speculum that allows safe completion of the procedure through a very limited incision.

Classical SU(2) Yang-Mills theory in 3+1 dimensional anti-de Sitter space is known to provide a holographic dual to a 2+1 system that undergoes a superconducting phase transition. We study the electrical conductivity and spectral density of an isotropic superconducting phase. We show that the theory exhibits a pseudogap at low temperatures and a nonzero Hall conductivity. The Hall conductivity is possible because of spontaneous breaking of time reversal symmetry., Comment: 1+16 pages. 4 figures. PDFLaTeX. v2: Corrections to the conductivity and statements about uplift

A first order phase transition usually proceeds by nucleating bubbles of the new phase which then rapidly expand. In confining gauge theories with a gravity dual, the deconfined phase is often described by a black hole. If one starts in this phase and lowers the temperature, the usual description of how the phase transition proceeds violates the area theorem. We study the dynamics of this phase transition using the insights from the dual gravitational description, and resolve this apparent contradiction., Comment: 11 pages, 1 figure. v2: minor clarifications, reference added

We study fractional quantum Hall states at filling fractions in the Jain sequences using the framework of composite Dirac fermions. Synthesizing previous work, we write down an effective field theory consistent with all symmetry requirements, including Galilean invariance and particle-hole symmetry. Employing a Fermi liquid description, we demonstrate the appearance of the Girvin--Macdonlald--Platzman algebra and compute the dispersion relation of neutral excitations and various response functions. Our results satisfy requirements of particle-hole symmetry. We show that while the dispersion relation obtained from the HLR theory is particle-hole symmetric, correlation functions obtained from HLR are not. The results of the Dirac theory are shown to be consistent with the Haldane bound on the projected structure factor, while those of the HLR theory violate it., Comment: 32 pages, 3 figures