It has previously been shown that cutaneous sensory input from across a broad region of skin can influence proprioception at joints of the hand. The present experiment tested whether cutaneous input ...from different skin regions across the foot can influence proprioception at the ankle joint. The ability to passively match ankle joint position (17° and 7° plantar flexion and 7° dorsiflexion) was measured while cutaneous vibration was applied to the sole (heel, distal metatarsals) or dorsum of the target foot. Vibration was applied at two different frequencies to preferentially activate Meissner's corpuscles (45 Hz, 80 μm) or Pacinian corpuscles (255 Hz, 10 μm) at amplitudes ∼3 dB above mean perceptual thresholds. Results indicated that cutaneous input from all skin regions across the foot could influence joint-matching error and variability, although the strongest effects were observed with heel vibration. Furthermore, the influence of cutaneous input from each region was modulated by joint angle; in general, vibration had a limited effect on matching in dorsiflexion compared with matching in plantar flexion. Unlike previous results in the upper limb, we found no evidence that Pacinian input exerted a stronger influence on proprioception compared with Meissner input. Findings from this study suggest that fast-adapting cutaneous input from the foot modulates proprioception at the ankle joint in a passive joint-matching task. These results indicate that there is interplay between tactile and proprioceptive signals originating from the foot and ankle.
Background Previous studies have suggested that injury to the anterior talofibular ligament (ATFL) may be linked to altered kinematics
and the development of osteoarthritis of the ankle joint. ...However, the effects of ATFL injury on the in vivo kinematics of
the ankle joint are unclear.
Hypothesis Based on the orientation of the ATFL fibers, ATFL deficiency leads to increased anterior translation and increased internal
rotation of the talus relative to the tibia.
Study Design Descriptive laboratory study.
Methods The ankles of 9 patients with unilateral ATFL injuries were compared as they stepped onto a level surface. Kinematic measurements
were made as a function of increasing load. With use of magnetic resonance imaging and orthogonal fluoroscopy, the in vivo
kinematics of the tibiotalar joint were measured in the ATFL-deficient and intact ankles of the same individuals.
Results A statistically significant increase in internal rotation, anterior translation, and superior translation of the talus was
measured in ATFL-deficient ankles, as compared with the intact contralateral controls. For example, at 100% body weight, ATFL-deficient
ankles demonstrated an increase of 0.9 ± 0.5 mm in anterior translation ( P = .008), an increase of 5.7° ± 3.6° in internal rotation ( P = .008), and a slight increase of 0.2 ± 0.2 mm in the superior translation ( P = .02) relative to the intact contralateral ankles.
Conclusion Deficiency of the ATFL increases anterior translation, internal rotation, and superior translation of the talus.
Clinical Relevance Altered kinematics may contribute to the degenerative changes observed with chronic lateral ankle instability. These findings
might help to explain the degenerative changes frequently observed on the medial talus in patients with chronic ATFL insufficiency
and so provide a baseline for improving ankle ligament reconstructions aimed at restoring normal joint motion.
Highlights • During supination-external rotation injury, Wagstaffe fragment might be avulsed. • Chaput fragment might be impacted by external rotation of the talus. • They would result in concomitant ...chondral injury of talus. • Fragments can be fixed by different methods depending on comminution of fragments. • After treatment, satisfactory recovery is anticipated clinically.
Abstract Background The incidence of osteochondral lesions (OCLs) in association with displaced ankle fractures has only been examined in two previous studies. In both studies magnetic resonance ...imaging (MRI) was performed prior to open reduction and internal fixation (ORIF). Because MRI may overdiagnose or overestimate the extent of OCLs in an acute trauma setting the aim of this study was to determine the incidence of OCLs after ORIF of displaced ankle fractures using MRI at medium-term follow-up, and to analyse if the severity of fracture or the clinical outcome correlates with the incidence of OCLs. Patients and methods Following institutional review board approval a total of 100 patients (mean age, 41.3 years; range, 17.9–64.3 years) with a displaced ankle fracture who had undergone ORIF according to the AO principles were included in this study. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was used to quantify the clinical outcome and MR images were evaluated for OCLs of the talus and distal tibia after a mean of 34.5 months (range, 17.5–54.1 months). Results OCLs were found in 40.4% of the patients. Logistic regression revealed a significant correlation between the severity of fracture and the incidence of OCLs. Patients with a trimalleolar fracture ( p = 0.04) or an ankle fracture dislocation ( p = 0.003) had a significantly higher risk for developing an OCL compared to those with a type B fracture. Logistic regression also demonstrated a significant correlation between the clinical outcome (AOFAS score) and the incidence of OCLs ( p = 0.01). The risk for developing an OCL increases up to 5.6% when the AOFAS score decreases by one point. Conclusion OCLs were frequently found in association with acute ankle fractures at medium-term follow-up, and the severity of fracture was associated with an increased number of OCLs. Considering the disadvantages of MRI including the high cost and limited availability, the results of this study may help to explain why anatomic surgical realignment of displaced ankle fractures may still be associated with poor clinical outcomes.
Weight-bearing computed tomography has multiple advantages in evaluating the hindfoot and ankle. It can assess hindfoot and ankle alignment, pathology in ankle arthritis, and complications related to ...total ankle replacements. It is an essential tool in ankle osteoarthritis diagnostic, preoperative planning, and total ankle replacement outcomes. It allows for better accuracy and reproducibility of alignment and implant size. In addition, it has the potential to more assertively detect complications related to weight bearing.
The ankle joint complex (AJC) is of fundamental importance for balance, support, and propulsion. However, it is particularly susceptible to musculoskeletal and neurological injuries, especially ...neurological injuries such as drop foot following stroke. An important factor in ankle dysfunction is damage to the central nervous system (CNS). Correspondingly, the fundamental goal of rehabilitation training is to stimulate the reorganization and compensation of the CNS, and to promote the recovery of the motor system's motor perception function. Therefore, an increasing number of ankle rehabilitation robots have been developed to provide long-term accurate and uniform rehabilitation training of the AJC, among which the parallel ankle rehabilitation robot (PARR) is the most studied. The aim of this study is to provide a systematic review of the state of the art in PARR technology, with consideration of the mechanism configurations, actuator types with different trajectory tracking control techniques, and rehabilitation training methods, thus facilitating the development of new and improved PARRs as a next step towards obtaining clinical proof of their rehabilitation benefits.
A literature search was conducted on PubMed, Scopus, IEEE Xplore, and Web of Science for articles related to the design and improvement of PARRs for ankle rehabilitation from each site's respective inception from January 1999 to September 2020 using the keywords " parallel", " ankle", and " robot". Appropriate syntax using Boolean operators and wildcard symbols was utilized for each database to include a wider range of articles that may have used alternate spellings or synonyms, and the references listed in relevant publications were further screened according to the inclusion criteria and exclusion criteria.
Ultimately, 65 articles representing 16 unique PARRs were selected for review, all of which have developed the prototypes with experiments designed to verify their usability and feasibility. From the comparison among these PARRs, we found that there are three main considerations for the mechanical design and mechanism optimization of PARRs, the choice of two actuator types including pneumatic and electrically driven control, the covering of the AJC's motion space, and the optimization of the kinematic design, actuation design and structural design. The trajectory tracking accuracy and interactive control performance also need to be guaranteed to improve the effect of rehabilitation training and stimulate a patient's active participation. In addition, the parameters of the reviewed 16 PARRs are summarized in detail with their differences compared by using figures and tables in the order they appeared, showing their differences in the two main actuator types, four exercise modes, fifteen control strategies, etc., which revealed the future research trends related to the improvement of the PARRs.
The selected studies showed the rapid development of PARRs in terms of their mechanical designs, control strategies, and rehabilitation training methods over the last two decades. However, the existing PARRs all have their own pros and cons, and few of the developed devices have been subjected to clinical trials. Designing a PARR with three degrees of freedom (DOFs) and whereby the mechanism's rotation center coincides with the AJC rotation center is of vital importance in the mechanism design and optimization of PARRs. In addition, the design of actuators combining the advantages of the pneumatic-driven and electrically driven ones, as well as some new other actuators, will be a research hotspot for the development of PARRs. For the control strategy, compliance control with variable parameters should be further studied, with sEMG signal included to improve the real-time performance. Multimode rehabilitation training methods with multimodal motion intention recognition, real-time online detection and evaluation system should also be further developed to meet the needs of different ankle disability and rehabilitation stages. In addition, the clinical trials are in urgent need to help the PARRs be implementable as an intervention in clinical practice.
Background
Grade III ankle sprains that fail conservative treatment can require surgical management. Anatomic procedures have been shown to properly restore joint mechanics, and precise localization ...of insertion sites of the lateral ankle complex ligaments can be determined through radiographic techniques. Ideally, radiographic techniques that are easily reproducible intraoperatively will lead to a consistently well-placed CFL reconstruction in lateral ankle ligament surgery.
Purpose
To determine the most accurate method to locate the calcaneofibular ligament (CFL) insertion radiographically.
Methods
MRIs of 25 ankles were utilized to identify the “true” insertion of the CFL. Distances between the true insertion and three bony landmarks were measured. Three proposed methods (Best, Lopes, and Taser) for determining the CFL insertion were applied to lateral ankle radiographs.
X
and
Y
coordinate distances were measured from the insertion found on each proposed method to the three bony landmarks: the most superior point of the postero-superior surface of the calcaneus, the posterior most aspect of the sinus tarsi, and the distal tip of the fibula.
X
and
Y
distances were compared to the true insertion found on MRI. All measurements were made using a picture archiving and communication system. The average, standard deviation, minimum, and maximum were obtained. Statistical analysis was performed using repeated measures ANOVA, and a post hoc analysis was performed with the Bonferroni test.
Results
The Best and Taser techniques were found to be closest to the true CFL insertion when combining
X
and
Y
distances. For distance in the
X
direction, there was no significant difference between techniques (
P
= 0.264). For distance in the Y direction, there was a significant difference between techniques (
P
= 0.015). For distance in the combined
XY
direction, there was a significant difference between techniques (
P
= 0.001). The CFL insertion as determined by the Best method was significantly closer to the true insertion compared to the Lopes method in the
Y
(
P
= 0.042) and
XY
(
P
= 0.004) directions. The CFL insertion as determined by the Taser method was significantly closer to the true insertion compared to the Lopes method in the
XY
direction (
P
= 0.017). There was no significant difference between the Best and Taser methods.
Conclusion
If the Best and Taser techniques can be readily used in the operating room, they would likely prove the most reliable for finding the true CFL insertion.
To provide a focused overview of the existing literature on the epidemiology of acute ankle sprains (lateral, medial, and high/syndesmotic) with an emphasis on incidence studies from the United ...States. In addition, we provide a brief overview of chronic ankle instability (CAI), posttraumatic osteoarthritis, and injury prevention to contribute to our understanding of the epidemiology of these injuries and the current state of the science on ankle sprains and ankle instability in sports medicine.
Acute ankle sprains are one of the most common musculoskeletal injuries, with a high incidence among physically active individuals. Additionally, acute ankle sprains have a high recurrence rate, which is associated with the development of CAI. Understanding the epidemiology of these injuries is important for improving patients' musculoskeletal health and reducing the burden of lower limb musculoskeletal conditions.
Acute ankle-sprain incidence rates are summarized among the general population, as well as among physically active populations, including organized athletics and military personnel, with a focus on incidence in the United States. The link between a prior ankle sprain and a future acute ankle sprain is described. We also discuss the association between the incident ankle sprain and adverse, long-term outcomes such as CAI and posttraumatic osteoarthritis. Finally, we summarize injury-prevention successes and future directions for research and prevention.
This information is useful for health care providers to understand the expected incidence rates of acute ankle sprains, be aware of the association between ankle sprains and negative short- and long-term outcomes, and be familiar with existing injury-prevention programs.
(1) To evaluate adequacy and reproducibility of the gravity and manual stress imaging in the diagnosis of unstable ankle fractures and (2) to evaluate the diagnostic utility of lateral talar ...displacement ratio (LTDR) derived in relation to the talar body width on ankle stress imaging.
Retrospective cohort study.
Level 1 Trauma Center.
One hundred seventy consecutive patients who presented with supination-external rotation 2 ankle fractures (OTA/AO 44-B2.1) requiring dynamic stress testing.
Dynamic stress imaging to determine ankle stability.
Ankle instability and subsequent need for surgical fixation as determined by dynamic stress imaging.
No statistical significant difference was found between the adequacy of gravity stress radiographs and manual stress images in regards to surgical decision-making (P = 0.595). Using manual and gravity stress images, receiver operating characteristic curves were generated for medial clear space (MCS) (area under the curve = 0.793, 0.901) and LTDR (0.849, 0.850), corresponding to thresholds of 10.5% and 10.2% for manual and gravity, respectively. Seventy-three of 105 patients (69.5%) with MCS > 5 mm and 62 of 75 patients (82.7%) with LTDR > 10% were offered surgical intervention. Sixty-two of the 77 patients (80.5%) offered surgery had both MCS > 5 mm and LTDR > 10%.
This study shows that manual stress radiographs are just as effective as gravity stress radiographs in making an assessment of ankle fracture stability as there was no difference in diagnostic value between gravity and manual stress imaging in regards to surgical decision-making. Use of additional radiographic measurements such as the LTDR can provide additional information in determining stability when MCS is within a clinical gray area.
Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
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