bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite-element analysis of the influence of tibial implant fixation design of total ankle replacement on bone–implant interfacial biomechanical performance
Authors: Yu Jian , Zhang Chao , Chen Wen-Ming , Zhao Dahang , chu Pengfei , Wang Shuo , Huang Jiazhang , Wang Xu , Ma Xin 
Published: November 2020

Purpose: Implant loosening in tibia after primary total ankle replacement (TAR) is one of the common postoperative problems in TAR. Innovations in implant structure design may ideally reduce micromotion at the bone–implant interface and enhance the bone-implant fixation and initial stability, thus eventually prevents long-term implant loosening. This study aimed to investigate (1) biomechanical characteristics at the bone–implant interface and (2) the influence of design features, such as radius, height, and length. Methods: A total of 101 finite-element models were created based on four commercially available implants. The models predicted micromotion at the bone–implant interface, and we investigated the impact of structural parameters, such as radius, length, and height. Results: Our results suggested that stem-type implants generally required the highest volume of bone resection before implantation, while peg-type implants required the lowest. Compared with central fixation features (stem and keel), peripherally distributed geometries (bar and peg) were associated with lower initial micromotions. The initial stability of all types of implant design can be optimized by decreasing fixation size, such as reducing the radius of the bars and pegs and lowering the height. Conclusion: Peg-type tibial implant design may be a promising fixation method, which is required with a minimum bone resection volume and yielded minimum micromotion under an extreme axial loading scenario. Present models can serve as a useful platform to build upon to help physicians or engineers when making incremental improvements related to implant design.
Association Between Hip Rotation and Activation of the Quadriceps and Gluteus Maximus in Male Runners
Authors: Mohammad Walaa S. , Elsais Walaa M. 
Published: November 2020

Background: Although running can provide health benefits, knee joint injuries are frequently reported by recreational runners. To date, the precise mechanism responsible for anterior knee pain remains elusive, and the source of symptoms is debated. Inconsistencies are found in the literature pertaining to the relationship between hip mechanics and activity in the quadriceps and gluteus maximus (GMax) during the running gait. Purpose/Hypothesis: To investigate the correlations between hip rotation and the activity in the quadriceps and GMax during running. We hypothesized that increased hip rotation is correlated with decreased activity in these muscles. Study Design: Descriptive laboratory study. Methods: A cohort of 30 healthy recreational runners volunteered to participate in the study (mean ± SD age, 28.8 ± 5.66 years; height, 1.73 ± 0.05 m; mass, 69 ± 6.3 kg; body mass index, 23.02 ± 1.42 kg/m2). Surface electromyography (EMG) data were obtained from the GMax, vastus medialis obliquus (VMO), and vastus lateralis obliquus (VLO). These data were synchronized with a motion capture system during a level-surface running activity at a speed of 3.2 m/s. Results: A significantly strong, negative correlation was found between the hip internal rotation angle and EMG activity of the GMax and the VMO. However, the VLO showed a significant, moderate, and positive correlation of activity with the hip internal rotation angle. Conclusion: The present study showed that during level-surface running, decreased GMax activity may be the cause of distal joint injuries and alteration in quadriceps muscle activity. Clinical Relevance: Because GMax activity is important for controlling the lower body mechanics during running, evaluating GMax activity and internal hip rotation angle is important to prevent the running-related knee injuries that are linked to quadriceps deficits, such as patellofemoral pain. Additionally, clinicians and trainers should consider strengthening the GMax while rehabilitating running-related knee injuries.
Comparison of Patient-Reported Outcomes for Major Pathologies of the Forefoot, Midfoot, Hindfoot, and Achilles Using PROMIS
Authors: Hu Daniel A. , Nayak Rusheel , Ogunkoya Elijah O. , Patel Milap S. , Kadakia Anish R. 
Published: November 2020

Background: Patient-Reported Outcomes Measurement Information System (PROMIS) is a newly developed patient-reported outcome that has been validated for the general foot and ankle population and has been applied to a variety of specific foot and ankle procedures. However, there is little data regarding clinical outcomes of patients at a more intermediate subgroup level. Thus, our study utilized PROMIS to provide normative data on pathologic conditions of the foot and ankle and assess postoperative outcomes based on anatomical location. Methods: Preoperative and 1-year postoperative PROMIS Physical Function (PF) and Pain Interference (PI) surveys were prospectively collected from a cohort of patients undergoing a foot and ankle procedure at a tertiary medical center. The cohort was split into forefoot (n = 136), midfoot (n = 44), hindfoot (n = 109), and Achilles (n = 62) procedure groups. Paired-t tests were used to compare preoperative versus postoperative outcomes within operative groups, while a 1-way analysis of variance (ANOVA) was used to detect differences in PROMIS scores between anatomic subgroups. Results: Paired t tests indicated that all 4 operative groups had significantly improved PROMIS PF and PI scores preoperatively versus 1 year postoperatively (all P < .001). One-way ANOVA demonstrated that there were no differences in postoperative PROMIS PF and PI scores between anatomic subgroups. A majority of patients achieved the minimal clinically important difference level of improvement in PROMIS PF and PI scores following surgery. Conclusions: All 4 operative groups had improvement in physical function and pain outcomes. Additionally, there were no differences in physical function and pain outcomes between operative groups. Level of Evidence: Level III, retrospective cohort study.
Influence of Topography on 3D printed Titanium Foot and Ankle Implants
Authors: Abar Bijan , Kelly Cambre N. , Allen Nicholas B. , Barber Helena , Kelly Alexander P. , Gall Ken , Adams Samuel B. 
Published: November 2020

Category: Basic Sciences/Biologics; Ankle; Trauma Introduction/Purpose Foot and ankle etiologies such as traumatic fractures, Charcot Arthropathy, nonunion after high risk arthrodesis and infectious debridement can result in critical sized bone defect (CSD). CSD is defined as bone loss greater than 1-2 cm in length or greater than 50% loss in circumference of bone. CSD remain a significant challenge in Orthopaedics. Custom 3D printed porous Titanium implants are currently being implemented when allograft is not an option. However, in a subset of cases, Titanium implants need to be removed due to infection or poor osseous integration where surrounding bone does not grow onto or through the scaffold. There is no one clear reason for poor osseous integration. This study explores effects of 3D printed topography on mechanical and biological properties. Methods: Titanium dog bones and discs were printed via laser powder bed fusion. Roughness groups were polished, blasted, as built, sprouts and rough sprouts. Roughness was measured with line measurement using a confocal microscope. To assess mechanical properties, tensile testing of samples from each roughness group produced stress strain curves. MC3T3 preosteoblast were seeded on discs. Samples were analyzed at 0, 2, and 4 weeks. A cell viability assay and confocal florescent microscopy assessed cell growth. Alkaline Phosphatase (ALP) assay and Quantitative Polymerase Chain Reaction (qPCR) examined cell differentiation. Extracellular matrix (ECM) was stained for collagen and calcium. Scanning Electron Microcopy (SEM) was done on sputter coated discs. Results: Rz, maximum peak to valley distance of the sample profile, for the polished, blasted, as built, sprouts and rough sprouts were 2.6, 22.6, 33.0, 41.4 and 65.1 µm respectively. The addition of printed roughness in the sprouts and rough sprouts group significantly diminished ductility resulting in early strain to failure during tensile testing. Cells adhered and proliferated on discs regardless of roughness group. There was no statically difference in ALP activity, but qPCR showed that rough groups (sprouts and rough sprouts) had diminished Osteocalcin gene expression at week 2 and 4. The ECM observed with SEM in the rough groups was more resistant to repeated washes and was more extensive compared to the less rough groups. Conclusion: The addition of 3D printed artificial roughness leads to inferior mechanical properties and confers no clear benefit regarding cellular proliferation. Printed topography increases the initiation of fractures resulting in diminished tensile strength and ductility. Concurrently, the resolution of LBF is not fine enough at this time to create surface features that enhance cell behavior. Therefore, data in this study suggest that artificially printing roughness is not an effective strategy to enhance osseous integration into Titanium implants for critical sized defects.
Mesenchymal Stem Cells Derived from Synovium and Fat Pad are Able to Treat Induced Ankle Osteoarthritis in Rats?
Authors: Ashkani-Esfahani Soheil , Lubberts Bart , Bhimani Rohan , DiGiovanni Christopher W. 
Published: November 2020

Category: Ankle Arthritis; Ankle; Basic Sciences/Biologics Introduction/Purpose: Osteoarthritis (OA) is a chronic disease and a significant cause of joint pain, tenderness, and limitation of motion. At present, no specific treatment is available and mesenchymal stem cells (MSCs) have shown promising potentials in this regard. Herein, we aimed to evaluate the repairing potentials of stem cells derived from synovium and fat pad in treatment of OA in ankle joint. Methods: Twenty-eight male rats (220+-20 g, aged 10-12 weeks), were randomly divided into four groups (n=7): C1: non- treated, C2: Hyalgan treated, E1: Adipose-tissue derived stem cell treated, and E2: synovial-membrane based stem cell treated groups. Collagenase type II enzyme was injected into the left ankle; after eight weeks, OA was developed. Then, stem cells were injected and rats were followed for three months. Afterwards, rats were euthanized and specimens and radiological images were provided. P-value<=0.05 was set as statistically significant. Results: Compared to C1, E1 and E2 groups showed significantly better results in all pathological criteria including surface, matrix, cell distribution, cell population viability, subchondral bone, and cartilage mineralization as well as joint space width and osteophytes developed in the joint (p<=0.001). Similarly, compared to C2 group, E1 and E2 had better scores regarding surface, matrix, cell distribution, and cell population viability (p<0.05). E2 showed considerably higher scores compared to C2 regarding subchondral bone and cartilage mineralization (p<0.05). Joint space width was similar between C2 and E groups. Conclusion: Treatment of OA of ankle with MSCs, particularly synovial-membrane derived stem cells, not only prevented but also healed OA to some extent in comparison to Hyalgan and non-treatment groups.
Tibial Torsion and Ankle Arthritis: Is External Tibial Rotation Associated with Varus Deformity in Patients with Ankle Arthritis?
Authors: Barber Collin C. , Hall Teresa , Madden Tyler , Kothari Parin D. , LaPointe Monica , Anderson John G. , Bohay Donald R. , Maskill John D. , Padley Michelle A. 
Published: November 2020

Category: Ankle; Ankle Arthritis; Hindfoot Introduction/Purpose: The effect of tibial torsion on lower extremity mechanical alignment has been well studied in the literature, including its effect on lower extremity osteoarthritis. It has been suggested that external tibial torsion is associated with cavus hindfoot deformity and may lead to varus osteoarthritis of the ankle. To our knowledge, there are no studies investigating this relationship. The purpose of this study is to characterize the relationship of tibial torsion with ankle coronal plane deformity in patients with ankle arthritis. Methods: The study is a retrospective, cohort of 223 patients who have undergone total ankle arthroplasty at a single institution. Preoperative computerized tomography was used to measure tibial torsion and coronal deformity. Descriptive statistics and regression analysis were used to analyze the data. Results: Descriptive analysis of all 223 patients demonstrated a maximum of 23.9 degrees varus and 20.5 degrees valgus among all patients. The mean for varus deformity was 6.86 degrees with a standard deviation of +- 6.39. Tibial rotation was calculated at an average of 20.8 degrees external rotation, with a maximum of 15.2 degrees internal rotation and 59.5 degrees external rotation in all patients. Plotting overall coronal ankle tilt versus tibial torsion revealed overall varus deformity with R2 of 0.016. Regression analysis of all varus deformities against external tibial torsion revealed a R2 of 0.02. Varus deformity 1 standard deviation above the mean against external tibial torsion demonstrated a R2 of 0.072. Valgus deformity against external tibial torsion revealed a R2 of 6.75 x10-5. Conclusion: An association between external tibial torsion and varus ankle arthritis has been proposed in the literature. The results of our study did not show an association between tibial torsion and coronal deformity in ankle arthritis in all patients undergoing total ankle arthroplasty at our institution. A difference may exist in certain subgroups, such as patients with neuromuscular disorders, but further investigation will be necessary to determine this relationship.
Dynamic Evaluation Of The Effect Of Syndesmotic Injury On Lateral Ankle Stability Using Fluoroscopy
Authors: Bhimani Rohan , Sato Go , Saengsin Jirawat , Hagemeijer Noortje , Lubberts Bart , Waryasz Gregory R. , Guss Daniel , DiGiovanni Christopher W. 
Published: November 2020

Category: Ankle; Sports; Trauma Introduction/Purpose: There is a high incidence of concomitance between lateral ankle ligament injuries and syndesmotic ligamentous injuries. However, it is unclear whether syndesmotic ligaments directly contribute toward the stability of the lateral ankle. Stress radiographs are an accepted technique to assess the degree of lateral ankle instability by providing a static view of the ankle when subjected to the anterior drawer (AD) and talar tilt (TT) tests. The aim of this study is to assess the effect of syndesmotic injury as well as combined syndesmotic and lateral ankle injury on the stability of the lateral ankle. Methods: Sixteen fresh frozen above-knee amputated cadaveric specimens, divided into two groups, underwent fluoroscopic evaluation for lateral ankle stability. In both the groups, the assessment was first done with all ligaments intact and later with sequential transection of anterior inferior tibiofibular ligament (AITFL), interosseous ligament (IOL), posterior inferior tibiofibular ligament (PITFL), anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL) and posterior talofibular ligament (PTFL). In all scenarios, two loading conditions were considered: (1) Anterior drawer test: 50N and 80N and (2) Talar tilt and Lateral clear space (LCS): 1.7Nm torque. The talar translation, talar tilt, and LCS were measured using Image J. Wilcoxon rank-sum test was used to compare the findings of each ligamentous transection state to the intact state. A p-value <0.05 was considered statistically significant. Results: In group 1 after transection of the AITFL and IOL, an increase in the anterior drawer, talar tilt, and lateral clear space values was found as compared to the intact state. Similarly, in group 2 the anterior drawer, talar tilt, and lateral clear space values significantly increased after transection of the AITFL and ATFL as compared to the intact state (p-values = 0.001). Conclusion: Lateral ankle instability appears after injury to two syndesmotic ligaments (AITFL and IOL), or after one syndesmotic ligament rupture (AITFL) with a concomitant anterior talofibular ligament rupture (ATFL). These findings suggest that surgeons should lower their threshold for stabilizing the syndesmosis if there is a concomitant lateral ankle ligament injury.
Using 3D Volume Measurements on Weightbearing Computed Tomography Scan to Diagnose Syndesmotic Instability
Authors: Bhimani Rohan , Ashkani-Esfahani Soheil , Lubberts Bart , Guss Daniel , Hagemeijer Noortje , Waryasz Gregory R. , DiGiovanni Christopher W. 
Published: November 2020

Category: Ankle Introduction/Purpose: Diagnosing syndesmotic instability, especially when subtle, remains challenging. Weight bearing computed tomography (WBCT) offers a unique opportunity to evaluate the distal syndesmosis under physiologic load while simultaneously comparing the injured and uninjured side. We hypothesized that WBCT volumetric measurements of the distal syndesmosis were increased on the injured side as compared to the contralateral uninjured side among patients with syndesmotic instability. Our secondary hypothesis was that these 3-dimensional calculations were an even more sensitive determinant of instability as compared to 2-dimensional methodology. Methods: Twelve patients with unilateral syndesmotic instability requiring operative fixation who underwent preoperative bilateral foot and ankle WBCT were included in the study group. The control group comprised of 24 patients without ankle injury who underwent similar imaging. For each WBCT scan, 2-dimensional measurements of the interspace between the distal fibula and tibia were measured 1cm above the joint line in the axial plane, namely the syndesmosis area and the direct anterior, middle and posterior difference. Furthermore, three volumetric measurements of the interspace between the distal fibula and tibia were evaluated: 1) from the tibial plafond extending until 3cm proximally, 2) 5cm proximally, and 3) 10cm proximally from the joint line. Results: In patients with unilateral syndesmotic instability, all weightbearing volumetric measurements were significantly larger on the injured side as compared to the contralateral, uninjured side (p<0.001). In the control group, there was no difference between syndesmotic volumes at any level. Of the three anatomic reference points, the volumetric measurement spanning from the tibial plafond to a level 5cm proximally had the highest relative volumetric ratio between the injured and uninjured side, suggesting it is more sensitive in distinguishing stable and unstable syndesmotic injuries (median ratios (IQR) 1.3(1.2-1.4), 1.8(1.6-2.1), 1.4(1.3-1.5), respectively; p<0.001). Additionally, this relative volumetric ratio was also more sensitive than 2-dimensional measurements (p=0.001). Conclusion: Volumetric measurement of the distal tibiofibular interspace using WBCT appears to be the most effective way to diagnose syndesmotic instability. The measurement from the tibial plafond extending until 5cm proximally is more sensitive to detect syndesmotic instability than using either more traditional 2D WBCT syndesmosis measurements or using more distal (3cm) or proximal (10cm) 3D volumetric measurements. This does not seem surprising given the overall spectrum and 3D nature of the syndesmotic injury across the injured population. Tables [Table: see text][Table: see text]
Prescribing Fewer Opioid Pills to Patients Undergoing Foot and Ankle Surgery: A Prospective Comparative Study
Authors: Caolo Kristin C. , Day Jonathan , Marion Celia , Ray Gabrielle S. , Johnson A. Holly 
Published: November 2020

Category: Ankle; Ankle Arthritis; Arthroscopy; Basic Sciences/Biologics; Bunion; Diabetes; Hindfoot; Lesser Toes; Midfoot/Forefoot; Sports; Trauma; Other Introduction/Purpose: This study aims to compare a novel opioid prescribing protocol aimed at reducing the number of opioid pills prescribed and consumed with an established, previously published protocol for foot and ankle surgery. We hypothesized that patients in the novel group would consume fewer opioids and report similar satisfaction with pain management compared with the established group. Methods: This study is a single center prospective study of 59 patients undergoing foot and ankle surgery who received a novel opioid prescribing protocol used by the senior author. Preoperatively, patients were counseled on the expectations of pain after surgery, received a take home pamphlet, and were prescribed opioids based on a sliding scale of procedures designated as minor (0-5 pills), moderate (5-10 pills) or major (15-20 pills). These patients were then compared to 84 patients from a previous prospective study from the same institution who received an opioid prescribing protocol with a maximum of 40-60 opioid pills. Patients were excluded if they used opioids or muscle relaxants preoperatively or had a known history of a substance use disorder. Patients completed surveys postoperatively for eight weeks reporting pain level, number of opioid pills consumed, refill requests, and satisfaction with their pain management plan. Results: There was a significant difference (p< 0.001) in mean pills consumed between the novel and established prescribing protocols at all time points (Table 1). During the entire postoperative period patients in the novel group had taken 21% of their prescribed pills compared to 40% in the established group (p=0.03). Patients had comparable levels of pain throughout the study (p>0.05 at POD 3, POD 7 and POD 14) and only differed significantly at POD 56 (p=0.005). Patients in the novel group did not request any refills, whereas patients in the established group requested a total of 9 refills over the course of the study. Conclusion: Patients receiving fewer opioid medications, along with preoperative coaching and take home materials, achieved equivalent analgesic effect when compared to patients receiving approximately double the amount of opioids. This study demonstrates that a sliding scale protocol with a maximum prescription of 20 opioid pills provides appropriate pain relief for most patients. This study confirms that patients on average take far fewer opioid pills than prescribed, and likely an even more limited prescribing protocol would be adequate for the majority of patients. This novel prescribing protocol ensures less opioids are both consumed and leftover for potential diversion in the community. [Table: see text]