bluuebunny/crossref_metadata_2025 huggingface dataset:
Mediated Skewed Diffusion of Issues Information: A Theory
Authors: McEwan Bree , Carpenter Christopher J. , Hopke Jill E.
Published: September 2018

The modern media ecology has changed drastically over the last decade yet scholarly theoretical perspectives lag behind lay theories regarding news diffusion making it difficult to fully articulate and understand the processes driving dissemination of information and persuasion across networks and media contexts. The proposed theoretical framework takes into account extant research on the multiple mechanisms, specifically, cognitive ego involvement, the media environment, and interpersonal processes that operate in concert to influence the way information about societal issues is diffused through digital communication channels. The theoretical framework of mediated skewed diffusion of issues information provides 11 testable propositions. These are put forth to provide a foundation and encourage future research on information dissemination, online persuasion, and position polarization.
Paraneoplastic Phenomena in a Patient With Locally Destructive and Metastatic Renal Cell Carcinoma
Authors: Pimienta Allen L. , Billings Thomas A. , Fish Robert G.
Published: September 2018

Renal cell carcinoma (RCC) accounts for approximately 80% of all primary renal neoplasms in United States causing approximately 65 000 new cases of RCC and 14 000 deaths each year. Symptoms of RCC typically include weight loss and night sweats but may also feature paraneoplastic phenomena in advanced stages as well as flank pain, gross hematuria, scrotal varicocele, inferior vena cava pathology, and a palpable abdominal mass. In this article, we present the course of a patient with advanced RCC, from initial presentation through workup and to eventual diagnosis. The case features late-onset symptoms, extensive paraneoplastic phenomena, and significant physical examination findings. We also review the literature available on RCC and critically analyze inefficiencies of the workup retrospectively.
Responses to Climate Variability in Urban Poor Communities in Pietermaritzburg, KwaZulu-Natal, South Africa
Authors: Hlahla Sithabile , Hill Trevor R.
Published: September 2018

South Africa’s rising urbanization has exacerbated the levels of urban poverty and inequality. The urban poor are increasingly vulnerable to the impacts of climate variability and have weak household risk response capacities. The study, through the use of a questionnaire survey, investigated how climate stressors such as the change of seasons, drought, heat waves, cold spells, hailstorms, floods, disease outbreaks, and veld fires are affecting four socioeconomically marginalized urban communities in Pietermaritzburg, KwaZulu-Natal. The respondents identified eight stressors that affect lifestyles and livelihoods; however, the majority do not have the means to cope adequately. Moreover, the coping strategies that were adopted were stop-gap reactive-type measures and provide limited capacity to build resilience and response capacity. With the projections that climate stressors will increase in frequency and duration in the region, the local government must increase investment in urban pro-poor climate change projects, which have been successful in some rural and urban areas, and educate the communities on climate-related risks so as to increase their knowledge and response capacities.
“There Is Always a Teacher Among Them”: Reflections From an American Medical Student on Time Spent With Medical Providers in the United States, China, and Vietnam
Authors: VanDolah Harrison
Published: September 2018

There is a famous Chinese saying by Confucius that goes “With three men walking, there is always a teacher among them.” In this narrative essay, I recount the story of how curiosity led me to find lessons about medicine from research on complementary and alternative medicine and medical service experiences in the “three men walking” of China, Vietnam, and the United States. As we visit the many teachers I had along the way, we will draw out various lessons from each experience and reflect on the value in experiencing cross-cultural medicine as a medical provider-in-training, with the hope that it will inspire other aspiring healers to cultivate their own curiosity. Travel with me from a bench outside a traditional Chinese medicine clinic in Beijing to orphanages in Vietnam and unearth what the “three men walking” of the United States, China, and Vietnam have to teach us.
Review of Sickle Cell Disease and Spinal Pathology
Authors: Rudy Hayeem L. , Yang David , Nam Andrew D. , Cho Woojin
Published: September 2018

Study Design:

Sickle cell disease (SCD) is a relatively common blood disorder that has profound implications on the musculoskeletal system and particularly the spine; however, there is a paucity of data in the literature discussing this important topic.

Objectives:

(1) To elucidate common spinal pathologies affecting patients with SCD, as well as the medical and surgical treatments available for these patients. (2) To discuss indications for surgical management of spinal complications of SCD and important for orthopedic surgeons when taking patients with SCD to the operating room.

Methods:

A narrative review of the literature was performed.

Results:

Patients with SCD have a significantly higher risk of developing spinal pathologies including vertebral osteomyelitis, compression fracture, vertebral vaso-occlusive crises, and osteoporosis, among others. In addition, patients with sickle cell disease are particularly susceptible to developing perioperative and post-operative complications including surgical site infection, implant malfunction, and vertebral body compression fracture. Postoperatively patients with SCD are prone to developing complications and adequate hydration is necessary in order to reduce complications of SCD.

Conclusions:

Several spinal pathologies may arise secondary to SCD and distinguishing these pathologies from one another may be challenging due to similarities in symptoms and inflammatory markers. Although most patients with SCD can benefit from conservative treatment involving rest, symptomatic therapy, antibiotic therapy, and/or orthosis, surgical intervention may be indicated in certain cases. It is preferable to avoid surgery in patients with SCD due to an increased risk of complications such as wound infection and vaso-occlusive crisis.
Acute Life-Threatening Hemorrhage in Neonates With Severe Hemophilia A: A Report of 3 Cases
Authors: Moreira Alvaro , Das Hrishikesh
Published: September 2018

Hemorrhagic shock is a rare, emergent condition that is often fatal in newborns. In this article, we report cases of 3 neonates presenting with acute, life-threatening hemorrhage who were subsequently diagnosed with severe hemophilia (<1% factor VIII). The first infant was tachycardic, pale, and had a precipitous drop in his hemoglobin secondary to a subgaleal hemorrhage. The second patient sustained a splenic rupture, a sequela that has been reported in only 4 other neonatal cases. The last infant presented with tonic-clonic seizures and respiratory distress. Head imaging demonstrated extracranial and intracranial hemorrhage, complications that can result in 20% mortality. All 3 patients were successfully treated with clotting factor concentrate and blood products. After normalization of factor VIII levels, the newborns did not develop any new hemorrhages and were discharged home within 3 weeks of birth. Pediatric providers should be aware that these signs and symptoms may be potentially lethal complications in neonates with severe factor VIII deficiency.
Public Health Seminar: Classics to Contemporary Cases for a New Pedagogy
Authors: Iannotti Lora , Chapnick Melissa , Eyler Amy , Hobson Angela , Sebert Kuhlmann Anne , Kreuter Matt
Published: September 2018

This best practice article explains a Public Health Seminar course that represents an innovative approach to public health pedagogy with demonstrated learning impacts. Reflecting many of the new Council on Education for Public Health competencies, this required course introduces incoming MPH students to the field of public health using a series of classic and contemporary cases, critically analyzed in a small group discussion format. Other modalities include succinct weekly written reflection critiques, rotating faculty discussion leaders, and a final project using various media platforms to communicate case narratives. Key pedagogical elements support students’ knowledge and skill acquisition: (1) small group discussion format, (2) case-based learning, (3) integration across MPH curriculum, and (4) communication skill building. The Public Health Seminar course offers the opportunity to motivate students early in a program, engaging them in relevant issues and providing insight into the importance of their MPH learning and public health professional practice.
Significance of BRICS: Regional Powers, Global Governance, and the Roadmap for Multipolar World
Authors: Chakraborty Sudip
Published: September 2018

The article justifies the optimism of new global order. The global financial crisis that had erupted in the USA during 2008 battered the global economy. The disaster paved the way for rethinking on changes in the architecture of global governance. The fragile political and economic global situation triggered by the crisis led to emergence of regional power confederacy, particularly within the developing world. Consequently, the importance of Brazil, Russia, India, China, and South Africa (BRICS) within the global governance structure has gone up. The steady emergence of BRICS in global politics has been mainly based on their excellent economic performances. This development on economic front coincides with increasing cooperation and coordination and formulating common positions on global political issues. BRICS, as a united entity, is expected to shape global governance in the twenty-first century. The influence already demonstrated by these emerging nations will surely continue to redistribute the balance of power in international financial institutions in favor of developing nations. Although the future of BRICS cannot be predicted with certainty, its combined efforts and the results of its meetings thus far reflect the potential of the group of emerging nations to change the existing distribution of power around the globe.
Everyday executive function and adaptive skills in children and adolescents with autism spectrum disorder: Cross-sectional developmental trajectories
Authors: Kouklari Evangelia-Chrysanthi , Tsermentseli Stella , Monks Claire P
Published: September 2018

Background and aims

The development of Executive Function in Autism Spectrum Disorder has been investigated using mainly performance-based executive function measures. Less is known about the development of everyday executive function skills. The present study aimed to identify the developmental patterns of everyday executive function of children and adolescents with autism spectrum disorder compared to neurotypical controls. The association between executive function and adaptive skills was also investigated.

Methods

The present study used a cross-sectional developmental trajectory approach and data were collected from 57 children and adolescents with autism spectrum disorder, matched to 63 controls of the same age (7–15 years).

Results

Results showed age-related performance declines in most everyday executive function domains (e.g. inhibition, working memory, planning) in autism spectrum disorder, whereas for executive function emotional control and shift, non-significant differences emerged across age in autism spectrum disorder. Everyday executive function predicted adaptive skills over and above age and IQ, in participants overall.

Conclusions and implications

These results suggest that several everyday executive function problems increase in adolescence in autism spectrum disorder and that these everyday executive function developmental patterns deviate to a great extent from those of typical development. Shedding more light on the developmental course of all types of executive function processes as well as their association with crucial social outcomes in autism spectrum disorder could contribute to a better theoretical understanding of the heterogeneity of the neurocognitive development in autism spectrum disorder.
The paradox of serving: Can genuine servant leadership gain followers’ respect for the leader? Evidence from Germany and Lithuania
Authors: Pircher Verdorfer Armin
Published: September 2018

A growing body of research shows that servant leadership is related to important organizational outcomes. Yet far less attention has been given to the mechanisms of servant leadership. This is particularly true for those dimensions of servant leadership that are inherently paradoxical and run counter to the common notion of leaders as strong influencers. In an effort to contribute to servant leadership research, this study investigated the relation between perceived genuine servant leadership behaviours (i.e. standing back, humility, authenticity) and respect for the leader, reflecting followers’ acceptance of their leader’s influence. Survey data were collected from 438 employees from various organizations in Germany and Lithuania and analysed via multi-group structural equation modelling. Results showed that the positive relation between perceived genuine servant leadership and respect for the leader was sequentially mediated by followers’ perceptions of alignment with ideal leader prototype and personal identification with the leader. Overall, this study elucidates the interplay between leadership and service, enhancing the understanding of how perceived genuine servant leadership has positive effects on followers. By drawing on two samples from different cultural clusters, this study strengthens the validity of the results and thus also contributes more generally to the cross-cultural applicability of servant leadership.
Incidence and Predictive Factors for Prolonged Use of Opioid Medication After Foot and Ankle Surgery
Authors: Ahmad Jamal
Published: September 2018

Category:

Other

Introduction/Purpose:

The purpose of this study is to evaluate the incidence and factors predictive for patients’ needs for opioid pain medication longer than 2 weeks after orthopaedic foot/ankle surgery in a single surgeon’s practice at a tertiary care center. We hypothesize that the number of patients that require opioids for pain management after 2 weeks post-operatively is low, but certain patient factors may be predictive for those individuals that request these medications at this time period.

Methods:

This is a prospective study of patients that received orthopaedic foot/ankle surgery between August 2016 and November 2017 by a single surgeon. Inclusion criteria involved surgical patients lacking chronic use of opioids. Patients regularly taking opioids pre-operatively were excluded from this study. Patients’ charts were reviewed for their age, weight, and medical co-morbidities. The diagnosis and procedure(s) that each patient received was recorded. Postoperatively, all patients received 60 tablets of opioids for one to be taken every 6 hours as needed for pain within 2 weeks from surgery. Every patient’s postsurgical course was examined for those that asked for and received opioids after 2 weeks from surgery. This event was defined as prolonged post-operative use of opioids.

Results:

Of 285 opioid-naïve patients that enrolled in this study and received foot/ankle surgery, 35 (12.3%) asked for and received opioids after 2 weeks from surgery. Three of these 35 patients asked for and received opioids after 4 weeks from surgery. No patients asked for and received opioids after 4 weeks from surgery. Age and anatomical location of surgery were not significantly prognostic for a post-surgical wound complication (P>0.05). Those patients of female gender, morbid obesity, and psychiatric conditions such as anxiety and depression were significantly predictive of requesting opioids after 2 weeks from surgery (P<0.05). Those individuals that received revision foot and/or ankle surgery trended towards a higher likelihood of requesting opioids after 2 weeks from surgery (P<0.15).

Conclusion:

This study demonstrates that the number of patients that require prolonged post-operative use of opioid medicine after orthopaedic foot and/or ankle surgery is low. However, this research shows that female patients with certain medical conditions such as morbid obesity and psychiatric illness are significantly likely to request opioids after 2 weeks from surgery. This is highly important when providing patients with realistic expectations of pain from foot/ankle surgery and the effectiveness and duration of opioids that help treat such pain.
PROMS and Radiological Outcomes in Mobile Bearing Total Ankle Arthroplasty for Patients with Varus or Valgus Deformity
Authors: Allport Jack , Bennett Adam , Ramaskandhan Jayasree , Siddique Malik
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

There is increasing evidence that outcomes for total ankle arthroplasty (TAA) are not adversely affected by pre-operative varus deformity. There is a sparsity of evidence relating to outcomes in valgus ankle arthritis. We present our outcomes using a mobile bearing prosthesis (Mobility TAA system, DePuy, Raynham, Massachusetts, USA) with a comparison of neutral, varus and valgus ankles.

Methods:

This is a single surgeon, retrospective cohort study of consecutive cases. Cases were identified from a locally held joint registry which routinely records PROMS data pre-operatively and at annual intervals. Patients undergoing primary TAA between March 2006 and June 2014 were included. Rrevision procedures along with those with inadequate radiographic images for deformity analysis were excluded. Patients with inadequate PROMS data were included in the radiological analysis but not the PROMS analysis. Data collected included FAOS (Womac Pain, Function and Stiffness), SF-36 scores and patient satisfaction. Radiological data was gathered from routinely taken AP weight bearing radiographs pre-operatively, immediately post-operatively and at final follow up. Pre-operative deformity was measured between the tibial anatomical axis and a line perpendicular to the talus. Patients were classified as neutral, varus (≥10 degrees varus) or valgus (≥10 degrees valgus).

Results:

230 cases (see image) underwent radiological classification (152 neutral, 60 varus, 18 valgus) and were included in the radiological analysis (mean follow-up 55.9 months). 164 cases were included in the PROMS analysis (mean follow-up 61.6 months). The groups were similar with regards to BMI and length of follow-up but neutral ankles were younger (P<0.001). Baseline scores were equal except physical health with valgus ankles scoring lowest (P=0.045). Valgus ankles had statistically better post-operative pain (P=0.0247) and function (P=0.012) than neutral ankles. Pre to post-operative change did not reach statistical significance except physical health where valgus outperformed neutral and varus (p=0.039). Mean post-operative angle was 3.1 and final angle 3.7 with no significant differences. There was no significant differences in revision rates.

Conclusion:

Our study confirms previous evidence that varus deformity does not affect outcome in TAA. Contrary to this, valgus ankles in our cohort performed better post-operatively than neutral ankles. Post-operative coronal radiological alignment was not affected by pre-operative deformity and was maintained over a number of years. Coronal plane deformity does not negatively impact either radiological or clinical outcomes in TAA should not be considered an absolute contra-indication.
Intraoperative Radiographic Assessment of Ankle Prosthesis Alignment
Authors: Barg Alexej , Weinberg Maxwell , Saltzman Charles
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

In the last 2 decades, total ankle replacement (TAR) has gained greater acceptance as a treatment option for patients with end-stage ankle osteoarthritis. However, TAR still has a higher failure rate than either hip or knee replacements. One of the most common reasons for TAR failure is malalignment of the prosthesis component which accounts for 15% of all failures. The purpose of this study was to assess ankle prosthesis alignment using intraoperative fluoroscopy images and to compare the results with postoperative weightbearing radiographs.

Methods:

Sixty-eight primary TARs were performed using the Zimmer trabecular metal implant (37 men and 31 women, mean age of 67.7±8.2 years) from October 2012 to August 2017. Alpha and beta angles were used to assess the alignment of the tibial component in the coronal and sagittal plane, respectively. Gamma angle was used to assess the alignment of the talar component in the sagittal plane. All measurements were performed by two observers (ICC 0.787-0.984). One observer evaluated all images twice at a 6-week interval to determine the intraobserver reliability (ICC 0.858-0.986).

Results:

There were significant differences between intraoperative and postoperative assessment for all three angles. For the alpha angle, the mean absolute difference was 1.8º±1.5º with a range between 0º and 6º (p = 0.001). For the beta angle, the mean absolute difference was 2.1º±1.5º with a range between 0º and 7º (p = 0.034). For gamma angle, the mean absolute difference was 2.0º±1.5º with a range between 0º and 6º (p = 0.002). The Pearson coefficient for the alpha, beta, and gamma angle was 0.664 (p < 0.001), 0.852 (p < 0.001), and 0.928 (p < 0.001), respectively.

Conclusion:

In the present study, radiographic assessment of the prosthesis’ component alignment demonstrated significant differences up to 7 degrees. This can be partially explained by the lack of a standardized radiographic technique to obtain fluoroscopic images, difficult identification of anatomic landmarks for intraoperative measurements, and distortion of x-rays using fluoroscopy.
The Effect of Patient Comorbidities on Intermediate Outcomes After Total Ankle Arthroplasty
Authors: Cunningham Daniel , Nunley James , DeOrio James , Easley Mark
Published: September 2018

Category:

Ankle

Introduction/Purpose:

Total ankle arthroplasty (TAA) has shown durable improvements in pain, function, and quality of life. Patient factors could affect intermediate to long-term outcomes after total ankle arthroplasty, and the impact of common medical comorbidities has not been fully characterized. The purpose of this study was to determine if common preoperative patient comorbidities had an effect on patient outcomes.

Methods:

Patients undergoing TAA between 1/2007 and 12/2016 were enrolled into a prospective study at a single academic center. Patients completed the following outcome measures before surgery and then in follow-up: AOFAS Hindfoot score, 36-item Short Form Survey (SF-36), Foot and Ankle Disability Index (FADI), and the Short Musculoskeletal Function Assessment (SMFA) score. Patient and operative factors along with pre-operative Charlson-Deyo and Elixhauser comorbidities with at least 10% prevalence across the entire population were assessed for association with changes in outcomes from pre-operative to the patient’s most recent follow-up. A minimum of 2 years of follow-up was required. Factors that met a significance threshold of p<0.05 in univariate analyses were incorporated into multivariable outcome models.

Results:

A total of 538 patients with an average follow-up of 4.3 years (range, 2 to 10 years) were included. While patients had significantly improved pain and function across all outcomes, smoking was associated with smaller improvements in AOFAS hindfoot score, AOFAS hindfoot function subscale, SF-36 physical summary scale, SF-36 total scale, and SMFA function scale. Prior foot and ankle surgery was associated with smaller improvement in AOFAS hindfoot pain subscale as well as VAS pain. Rheumatoid arthritis was associated with smaller improvement in SF-36 total and physical summary subscale scores while obesity was associated with smaller improvement in the FADI. Smoking had the largest impact on results, and produced a moderate effect size. All other variables had trivial to small effect sizes.

Conclusion:

While patient outcomes improved significantly after TAR at intermediate duration follow-up, smoking, prior surgery, rheumatoid arthritis, and obesity were risk factors for reduced improvement in outcomes. Smoking was associated with a moderate effect size, but all other factors had only small impact on patient-reported outcomes. Active smokers should be counseled on their risk of smaller improvements in outcomes, and it may be inadvisable to perform TAR on these patients.
Forefoot Striking Is More Effective in Reducing Loadrates than Increasing Cadence in Runners
Authors: Futrell Erin , Davis Irene
Published: September 2018

Category:

Sports

Introduction/Purpose:

Vertical impact forces are highly influenced by the way the foot contacts the ground. These impact forces are associated with high loading rates which have been related to running injuries. As a result, clinicians have begun to use gait retraining interventions to reduce loadrates and prevent future impact-related injuries. Two types of gait retraining techniques have been promoted to reduce excessive running impacts. The first involves increasing cadence (CAD), or number of steps per minute, by 5-10%, thereby reducing stride length. The second type of gait retraining involves landing on the ball of the foot at ground contact, or using a forefoot strike (FFS). Both of these gait-retraining styles have been reported to reduce impacts, but they have not been compared with each other.

Methods:

33 healthy runners (9M, 24F), running 5-15 mpw, with a rearfoot strike pattern with cadence < 170 steps/min were recruited. Subjects were randomly allocated to either FFS or CAD retraining. All subjects underwent an 8-session gait retraining program (over 2-3 wks) with auditory feedback on a treadmill. The CAD group ran to a digital metronome to increase cadence by 7.5%. The FFS group wore a wireless accelerometer that provided an auditory signal on footstrike pattern. A gait analysis was conducted at baseline, 1 wk, 1 month, and 6 months. Variables included vertical average and instantaneous load rates (VALR, VILR). A 2 x 4 repeated measures ANOVA was used to compare differences within and between the CAD and FFS groups at baseline, 1 week, 1 month and 6 months post retraining. For variables with significant interactions, simple main effects of group, as well as time were further explored using one-way ANOVA

Results:

There were significant interaction effects of time*group for VALR (p= 0.001), VILR (p=0.001) and foot angle (p< 0.001), but not cadence. For the simple main effects for the CAD group, VALR reduced by 14%, 7% and 16% at 1 week, 1 month, and 6 months post gait retraining respectively, compared with baseline (Figure 1). However, these reductions were not significant. For the FFS group, VALR was significantly reduced by 50%, 51% and 51% at 1 week, 1 month, and 6 months post gait retraining respectively. Interestingly, both the CAD and FFS groups increased cadence by similar amounts.

Conclusion:

Transitioning to a FFS pattern is significantly more effective than increasing CAD when reducing vertical loadrate (both VALR and VILR) is the goal. These changes persisted out to 6 months post gait retraining, suggesting permanence of the new pattern.
The Effect of Age in Total Ankle Replacement
Authors: Gaugler Mario , Hintermann Beat , Schweizer Christine
Published: September 2018

Category:

Ankle

Introduction/Purpose:

Over the last decades, total ankle replacement (TAR) emerged as a reliable treatment option in end-stage ankle osteoarthritis (OA) while preserving motion and physiological load. As these are strong arguments for TAR from an active patient’s perspective, it appears obvious that young patients show great interest in it. In the late 90s, 2nd generation implants showed a high revision rate, which has led to great cautiousness for TAR in young and active patients. Despite recently published data on 3rd generation implants showed a comparable outcome within different age groups, the question to debate remains whether TAR is advised in younger patients. The purpose of this study was to compare the clinical outcome and revision rate after TAR in patients younger and older than 50 years.

Methods:

A consecutive series of 813 primary TARs (3rd generation HINTEGRA, 446 male, 367 female), performed between May 2003 and December 2013, were enrolled. 129 patients (16%) were younger than 50 years and 784 (84%) were older than 50 years at time of surgery. The clinical outcome (AOFAS hindfoot score) and survivorship (revision of a metallic component as endpoint, or ankle fusion) of patients aged <50 years and ≥50 years at the time of surgery were compared.

Results:

Posttraumatic OA as indication for a TAR was more common in the younger cohort (81 vs. 78%) and the mean follow-up time was slightly longer (5.6 vs. 5.0 years). Younger patients had a significantly lower preoperative AOFAS score (39 vs. 44). Both groups showed an identical clinical improvement that resulted in a lower total AOFAS score (66 vs. 71) in the younger group at last follow-up. Overall, a total of 81 ankles (10%) were revised (13 patients <50 years, 68 patients ≥50 years). In 62 ankles (77%) a revision of a metallic component, in 19 ankles (23%) a conversion to ankle fusion was performed. The estimated 10-year revision rate was 15.7% for patients aged > 50 years and 18.4% for patients aged ≥ 50 years.

Conclusion:

Beside of the higher incidence of posttraumatic OA in younger cohort, the high activity level and biomechanical demands may lead to a greater subjective limitation, which explains their significantly lower baseline AOFAS score. However, both groups showed similar clinical improvement and overall revision rates. Our findings support and back up recently published data from 3rd generation TARs to be an effective and reliable treatment option in end-stage ankle OA in young patients. However, a long-term follow-up and individual analysis of all failures leading to revision is of high importance.
Flecting Osteotomy of the Distal Tibia for Salvage of an Asymmetric Osteoarthritic Ankle Joint
Authors: Hintermann Beat , Scheidegger Patric , Lang Tamara Horn , Zwicky Lukas
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

Deformity of the distal tibia in the sagittal plane with increased posterior tilt of the articular surface (recurvatum deformity) results in altered biomechanics and high contact pressure in the anterior tibiotalar joint with consecutive osteoarthritis (OA). As the talus becomes anteriorly extruded out of ankle mortise, the distance between its center of rotation and longitudinal axis of tibia is typically seen to be increased. In an attempt to restore physiologic load of such misaligned ankles in the sagittal plane, we have started to use a correcting osteotomy of the distal tibia to realign the center of rotation of talus and tibial axis. The aim of this study was to analyze the radiological and clinical outcome in a consecutive series of patients.

Methods:

39 patients (female, 12; male 27; age 47 [28 to 72, SD 10.6] years) were treated with a flecting osteotomy of the distal tibia for a symptomatic misalignment in the sagittal plane with the use of an anterior opening wedge osteotomy (n = 28), posterior closing wedge osteotomy (n = 9), or dome-shaped osteotomy from medially (n = 2). If necessary, simultaneous corrections in the frontal plane were performed to address additional valgus/varus deformities. Standard weight-bearing radiographs were used pre- and postoperatively to evaluate the tibial anterior surface angle (TAS), tibiotalar surface angle (TTS), tibial lateral surface angle (TLS), calcaneal pitch and talar offset ratio (TOR). A four-staged flecting score was used to classify the grade of OA of the tibiotalar joint in the sagittal plane, also taking the coronal joint congruency into account.

Results:

The cumulative survival rate of the joint was 77% (95% CI: 48-86%) after 3 years, with 9 patients needing a joint sacrificing procedure (total ankle arthroplasty, 7; ankle fusion, 2). In the remaining 30 patients, pain decreased 2.0 points on the VAS (p <0.001), and the AOFAS hindfoot score improved by 17 points (p<0.001). The ROM did not change significantly. Patient satisfaction with the outcome was good in 68% and moderate in 25%, 7% were not satisfied. The mean TLS increased by 6.6 (SD 5.84) degrees, the mean TOR decreased 0.239 (SD 0.1814). TAS, TTS and calcaneal pitch did not change significantly. Ten ankles (26%) showed an improvement, 22 (56%) no change and 7 (18%) a worsening in the flecting score.

Conclusion:

The flecting osteotomy of the distal tibia was found to be an effective method to restore the tibiotalar joint congruency through moving the tibia axis anteriorly to the center of rotation of the talus, and lengthening the lever arm of the Achilles tendon. Besides normalizing the joint reaction forces of the tibiotalar joint, the procedure was also found to be effective to stabilize the talus against anterior extrusion. However, with a failure rate of 23%, there is need for further studies to determine the indication and limitation of this procedure.
Reliability and Validity of Scores from the Foot and Ankle Ability Measure
Authors: Matheny Lauren , Clanton Thomas
Published: September 2018

Category:

Ankle

Introduction/Purpose:

A commonly used measure of ankle function is the Foot and Ankle Ability Measure (FAAM). To support interpretation of the FAAM, evidence of reliability and validity must be established. Some studies have assessed FAAM scores; however, these studies had small sample sizes, sample characteristics that may limit generalizability, and did not report reliability estimates. These studies were also unable to account for person ability and item difficulty, a unique feature Rasch modeling offers, which is key when attempting to generalize to other populations. The purpose of this study was to determine whether there is evidence of reliability and validity for the FAAM ADL and Sport scales, utilizing the Rasch model, in patients who have undergone surgical intervention for the treatment of an ankle injury.

Methods:

Evidence of reliability and validity were determined utilizing the Rasch measurement model, a special case of item response theory, which has been used to develop new patient reported outcome measures and improve existing measures. This is a widely used technique that may be used as an alternative to classical test theory due to advantages including generalizability across samples, accounting for response options not equally spaced in terms of ability, and identifying poorly functioning items. The scale of interest is measured in terms of item difficulty and generates estimates of locations of individual items (item difficulty) and ability level along a common interval-level scale (log-odds). To identify misfit items, outfit mean-square (MNSQ) and infit MNSQ statistics were assessed. Infit and outfit MNSQ range from 0 to positive infinity (ideal value of 1.0 means observed variance = expected variance; acceptable value range 0.5 -1.7). Person reliability was also reported (analogous to Cronbach’s a).

Results:

There were 456 patients included in the study(192 females, 264 males)(average age=47.6 years(18-79). Rasch analysis showed good evidence of reliability for FAAM ADL and FAAM Sport scores (Figure 1). Person reliability was 0.87 for FAAM ADL and 0.89 for FAAM Sport. Outfit MNSQ values for FAAM ADL items 11 (Coming Up On Toes) and 10 (Squatting) were high (2.17, 1.96). Item 19 “Light/Moderate Work” was low(0.48), indicating item redundancy. For FAAM Sport, all outfit values (range 0.67 -1.64) were within the acceptable range. For internal scale validity, infit MNSQ values for FAAM ADL items 11 and 10 were high(2.30, 2.05). All other infit values (range 0.61 -1.48) were within the acceptable range. For FAAM Sport, all infit values (range 0.74 -1.65) were within the acceptable range.

Conclusion:

This study provides good evidence of reliability for FAAM ADL and Sport scores in a wide range of patients who underwent ankle surgery, which may demonstrate wide clinical applicability. Both scales demonstrated good internal scale validity; however, 3 FAAM ADL items may indicate the need for further scale development for use in a diverse ankle population.
Fixation of Ankle Fractures
Authors: Molloy Andrew , Whitehouse Samantha , Mason Lyndon
Published: September 2018

Category:

Trauma

Introduction/Purpose:

Ankle fractures are one of the most common fractures. Historically these have been frequently treated by non-specialists and junior staff. In 2011 we presented high malunion rates, which have been mirrored in other departments work. We present the results of system changes to improve the results of ankle fracture fixation

Methods:

Image intensifier films were reviewed on PACS and scored based on the criteria published by Pettrone et al. At least two blinded assessors assigned scores independently. Patients clinical data was collected from medical records. In 2011 we presented the results of fixation in 94 consecutive patients (Group 1) from 2009. Following this there was period of education in the department to allow change. 68 patients (Group 2) were then reviewed from a 7 month period in 2014 Multiple system changes were introduced in the department including; new treatment algorithms, dedicated foot and ankle trauma lists and clinics, and next day review of all intra-operative radiographs by independent attending. Prospective data was collected on 205 consecutive cases (Group 3) from 01/01/15 – 09/30/16

Results:

Patients in group 1 had a malreduction rate of 33%. The major complication rate in this group was 8.5% (8 patients); with only one of these occurred in a correctly reduced fracture. These complications included 4 revision fixations, 2 deep infections and 1 amputation. Following the period of re-education, in Group 2, the mal-reduction rate deteriorated to 43.8%. In this group the major complication rate was 10.9%; including 6 revision fixations and 1 ankle fusion. In Group 3, following overall system changes, the malreduction rate was 2.4%. This result is statistically significant. The major complication rate fell to 0.98%; 1deep infection and 1 amputation (in a polytrauma patient with vascular injury). This result is again statistically significant.

Conclusion:

Our initial results show that very poor results are a consequence when sufficient attention is not given to what are frequently considered to be ‘simple’ fractures. In group 2 we demonstrated that soft educational changes (eg presentations, emails) are ineffective in improving results. We have demonstrated that hard (institutional system) changes in our department provided statistically significant improvements. These changes allowed the correct surgeon for the fracture in both determining the treatment plan and operating. With these changes, malreduction rates fell from 43.8% to 2.4% and major complication rates from 10.9% to 0.98%
Knee Kinetics and Kinematics in Patients with Ankle Arthroplasty and Ankle Arthrodesis
Authors: Roney Andrew , Kraszewski Andrew , Fansa Ashraf , de Cesar Netto Cesar , Ellis Scott , Deland Jonathan , Levine David , Demetracopoulos Constantine
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

Ankle arthritis is a debilitating problem, causing significant pain and functional limitations. Previous literature suggests patients treated with ankle arthroplasty (TAA) versus ankle arthrodesis (AA) may have better function and have lower risk for adjacent joint arthritis in the foot. However, there is little research on how these interventions impact proximal joints, such as the knee. The knee adduction moment (KAM) is a surrogate measure for the force experienced at the medial tibiofemoral compartment and is linked with the onset and progression of knee osteoarthritis. We hypothesized that patients with TAA and AA will exhibit altered frontal plane kinematics and kinetics in the affected limb compared to the contralateral unaffected side, and that the AA cohort will have a significantly greater KAM compared to TAA.

Methods:

Instrumented 3D walking gait was recorded in 10 TAA and 10 AA patients, minimum 2-year post-operatively. Subjects were demographically matched, had unilateral ankle arthritis and lacked complications such as adjacent joint arthritis, neuropathy or significant weight-bearing pain. The TAA patients had either a Salto-Talaris or INBONE prosthesis. Lower limb kinematic and kinetic data were measured with reflective skin surface markers and floor-embedded force plates at self-selected walking speeds. Average first and second peak KAMs [N-m/kg], KAM impulse [N-m-s/kg] and range-of-motion (ROM, [°]) were calculated on both the affected and unaffected limb for each patient. Group differences in KAM, impulse and ROM between TAA and AA interventions and the affected and unaffected limb were analyzed using a 2-sample unpaired t test. P-values less than 0.05 were considered significant.

Results:

See Table 1 for demographic and statistical analyses summary. Between the affected and unaffected limbs in each surgical cohort there were no significant differences in the KAM’s first and second peak or impulse (p>0.135) and no difference in the knee ROM in any plane (p>0.214). When comparing AA with TAA, the average first peak KAMs generated while walking were 0.07N-m/kg greater in the TAA treatment but that difference was not significant (p=0.429). The second peak KAM was, on average, 0.1N-m/kg greater within TAA patients but was also not statistically different from AA patients (p=0.594). The KAM impulse and ROM in all 3 planes were not different between intervention types (p>0.318).

Conclusion:

TAA and AA may not significantly affect ipsilateral knee kinetics and KAMs in short term follow-up. This study highlights the importance of continuing to study these parameters in larger cohorts of patients with longer follow-up to determine how our treatment of end-stage ankle arthritis may affect the incidence or progression of ipsilateral knee osteoarthritis.
Influence of Tibial Component Position on Altered Kinematics Following Total Ankle Arthroplasty During Simulated Gait
Authors: Saito Guilherme , Sturnick Daniel , Deland Jonathan , Ellis Scott , Demetracopoulos Constantine
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

Correct positioning of total ankle arthroplasty (TAA) implants has been associated with superior clinical outcomes. Furthermore, biomechanical studies have demonstrated that poor alignment of the components may lead to early component wear, compromising the longevity of the prosthesis. Malpositioning of TAA implants affects ligament engagement patterns and joint contact mechanics, possibly leading to altered joint kinematics. However, the correlation between implant position and ankle joint motion is still unclear. The objective of this study was to assess the effect of tibial component position on ankle kinematics following TAA during simulated gait.

Methods:

Eight mid-tibia cadaveric specimens were utilized in this IRB approved study. The stance phase of gait was simulated both pre- and post-TAA in each specimen using a six-degree of freedom robotic platform. Ground reaction forces and tibial kinematic from in vivo data were replicated while physiologic tendon force profiles were applied to each extrinsic ankle tendons by linear actuators instrumented. Ankle kinematics was measured from reflective markers attached to bones via surgical pins. TAAs were completed using a common fixed-bearing total ankle system following the manufacturer recommended protocol (Salto Talaris, Integra LifeSciences). Using reconstructed CT data, 3D tibial component position relative to a standard ankle joint reference was characterized (Figure 1A). The effect of tibial component position on absolute differences in ankle kinematics (pre – post TAA) was assessed using linear regression with a level of significance set to p = 0.05.

Results:

Differences in ankle joint kinematics were only identified in the transverse plane, where internal talar rotation was significantly increased following TAA compared to the native condition (Figure 1B). The medial position of TAA tibial components was found to be positively associated with increased internal talar rotation (Figure 1C; β = 1.861 degrees/mm, R2 = 0.72, p = 0.008). No other measurements of tibial component position (anterior-posterior/inferior-superior position, sagittal/frontal/transverse plane angle) were found to be significantly associated with altered ankle kinematics following TAA (All β < 0.1 and p > 0.05).

Conclusion:

This study suggests that medial positioning of the tibial implant affects ankle kinematics. During operative procedures the tibial component is usually positioned in order to preserve bone stock of the medial and lateral malleolus. However, little attention is given to the position of the implant in relation to the center of the tibial axis. This finding could have clinical implications for techniques implemented during surgical procedures and for the development of new instrumentation systems.
Concentrated Bone Marrow Aspirate May Decrease Postoperative Cystic Occurrence Rate in Autologous Osteochondral Transplantation for Osteochondral Lesions of the Talus
Authors: Shimozono Yoshiharu , Hurley Eoghan , Kennedy John
Published: September 2018

Category:

Ankle

Introduction/Purpose:

Autologous Osteochondral Transplantation (AOT) provides excellent clinical outcomes for osteochondral lesions of the talus (OLT), however, there is concern regarding the presence of cysts at the bone interface. The presence of subchondral bone cysts has been previously shown to be correlated with graft failure, and high rates of postoperative subchondral cysts formation of up to 75% at short-term follow-up have been reported. Concentrated bone marrow aspirate (CBMA) may have the potential to improve integration between the graft and native articular cartilage and bone, and may reduce interface cyst production. The purpose of this study was to clarify the efficacy of CBMA in AOT as compared with AOT alone, regarding the presence of postoperative cyst formation, postoperative functional outcomes and magnetic resonance imaging (MRI) outcomes.

Methods:

Patients who underwent AOT between 2004 and 2008 were retrospectively assessed at a minimum of 5-year follow-up. Twenty-eight patients were treated with AOT and CBMA (AOT/CBMA group) and 26 patients were treated with AOT alone (AOT alone group). Clinical outcomes were evaluated using the Foot and Ankle Outcome Scores (FAOS) and Short-Form 12 (SF-12) preoperatively and at final follow-up. Postoperative MRI was evaluated with the modified Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. Cystic formation was evaluated on postoperative MRI, and cyst diameter and cyst location were assessed.

Results:

Fifty-four of 59 eligible patients were included. Of those, 28 patients were treated with AOT and CBMA and 26 patients were treated with AOT alone. The mean FAOS and SF-12 significantly improved in both AOT/CBMA and AOT alone groups, but there were no statistical differences between groups in FAOS (80.6 vs 75.4, p = 0.217) and SF-12 (71.1 vs 69.2, p = 0.694) at final follow-up. Additionally, there was no difference in the mean MOCART Score (80.4 vs 84.3, p = 0.484). However, AOT/CBMA did result in a statistically lower rate of cyst formation (46.4% vs 76.9%, p = 0.022) (Table 1). No statistical differences were found between groups in cyst location and cyst diameter (table 1).

Conclusion:

CBMA reduced the postoperative cystic occurrence rate in patients treated with AOT, although CBMA did not result in significant differences in functional outcomes nor MOCART score in patients who underwent AOT.