Ankle Motion Research Articles

Characteristics of the stand-to-sit motion in healthy older women : Evaluation of sitting impact by measurement of ground reaction forces.

Objectives : The aims of this study were to examine the biomechanics of StandTS movements in older adults and to identify their optimal StandTS motion by measuring sitting impact forces. Methods : Healthy older women (n = 17) and healthy young women (n = 18) were asked to perform SitTS and StandTS motions at a natural speed using a chair. We measured the ground reaction forces from the participants' feet and the chair, the angle of the trunk and ankle, vertical velocity, and postural muscle activities using a force plate, motion analyzer, and electromyography, respectively. Results : Sitting impact force was significantly greater in the older women than in the young women during the StandTS motion. There was a significant difference between the trunk angle and the ankle angle during the StandTS motion and sitting impact force had a significant negative correlation with the ankle joint motion in the older women. Conclusions : The ankle joint strategy was characterized by body sway resembling a single-segment-inverted pendulum and suggests that this response is less developed in the older adult. These results indicate that the ankle joint strategy may be an important factor involved in the sitting impact force. J. Med. Invest. 69 : 278-286, August, 2022.

The effect of backpack load on intersegmental motions of the foot and plantar pressure in individuals with mild flatfoot

BackgroundThe feet play an essential role in shock absorption, and foot posture is closely related to gait. The compensatory mechanism under heavy-load conditions in individuals with mild flatfoot is poorly understood. In the authors’ country, individuals with mild flatfoot are drafted as active-duty soldiers and participate in military rucking wearing heavy backpacks. This study investigated the effect of backpack load on gait and foot plantar pressure and possible differences in participants with mild flatfoot. The average weight of the backpack during military rucking (approximately 20 kg), was simulated in this study.MethodsThis study prospectively enrolled 30 healthy young males, divided into a control group (CON, n = 15) and a mild low-arched group (MLA, n = 15), based on the presence of flatfoot. Segmental foot kinematics were evaluated using a three-dimensional multi-segment foot model, and gait data of the temporal and spatial parameters were obtained. The dynamic plantar pressure was simultaneously measured using a pedobarography platform with gait trials. The protocol was repeated with all participants wearing 20 kg backpacks. Comparisons between the baseline and loaded states, as well as comparison between groups, were conducted.ResultsAlthough the cadence, gait speed, and stride length decreased in the loaded condition, step time and proportion of the stance phase increased in both groups. Although the MLA group showed more supinated and abducted positions of the forefoot and more pronated positions of the hindfoot than the CON group, the change in intersegmental foot and ankle motion in each group after backpack loading was minimal. However, the former showed a larger step width and a greater increase in contact area in the midfoot region, while the latter demonstrated a greater increase in peak pressure.ConclusionsIndividuals with mild flatfoot demonstrated significantly different gait curve patterns (waveforms) compared to the controls. In the loaded condition, the CON and MLA groups may have adopted different strategies to maintain balance during gait. We suggest that although individuals with asymptomatic mild flatfoot are drafted as active-duty soldiers, they should be thoroughly investigated under loaded conditions, and orthoses may be helpful.

Improving IMU-Based Prediction of Lower Limb Kinematics in Natural Environments Using Egocentric Optical Flow.

We seek to predict knee and ankle motion using wearable sensors. These predictions could serve as target trajectories for a lower limb prosthesis. In this manuscript, we investigate the use of egocentric vision for improving performance over kinematic wearable motion capture. We present an out-of-the-lab dataset of 23 healthy subjects navigating public classrooms, a large atrium, and stairs for a total of almost 12 hours of recording. The prediction task is difficult because the movements include avoiding obstacles, other people, idiosyncratic movements such as traversing doors, and individual choices in selecting the future path. We demonstrate that using vision improves the quality of the predicted knee and ankle trajectories, especially in congested spaces and when the visual environment provides information that does not appear simply in the movements of the body. Overall, including vision results in 7.9% and 7.0% improvement in root mean squared error of knee and ankle angle predictions respectively. The improvement in Pearson Correlation Coefficient for knee and ankle predictions is 1.5% and 12.3% respectively. We discuss particular moments where vision greatly improved, or failed to improve, the prediction performance. We also find that the benefits of vision can be enhanced with more data. Lastly, we discuss challenges of continuous estimation of gait in natural, out-of-the-lab datasets.

Anterior-Inferior Tibiofibular Ligament Suture-Tape Augmentation for Isolated Syndesmotic Injuries

Category:Sports; AnkleIntroduction/Purpose:Aggressive surgical treatment of isolated syndesmotic injuries has recently gained some traction in the media and sports world. New developments in syndesmotic fixation aim to restore native syndesmotic stability and ankle motion with a goal of returning athletes to sport quickly. However, the best surgical technique is debated. Dynamic repair with a suture- button (SB) can provide an accurate reduction of the syndesmotic space but may alter the rotational kinematics of the fibula. Previous studies have suggested that repair or reconstruction of the anterior-inferior tibiofibular ligament (AITFL) may restore the dynamics of the syndesmosis better than other devices. The purpose of this study was to biomechanically compare SB fixation and augmented repair of the AITLF using suture and suture-tape (ST) in isolated syndesmotic injuries.Methods:Twelve unpaired lower leg specimens underwent biomechanical testing in 6 states: 1) intact, 2) AITFL suture repair alone, 3) AITFL suture repair + ST augmentation, 4) AITFL suture repair + ST augmentation + SB fixation, 5) AITFL suture repair + SB fixation, and 6) complete syndesmotic injury. The testing consisted of subjecting the ankle joint to 6 cycles of 5 Nm internal and external rotation torque under a constant 750 N axial compression load in a dynamic tensile testing machine. A lower level of torque was chosen than in previous studies in order to replicate physiologic motion of everyday activities instead of injury level forces. The spatial relationship between the tibia and fibula and tibia and talus was continuously recorded using a 5-camera motion capture system.Results:AITLF suture repair and suture repair + ST augmentation repair constructs showed no statistically significant change in fibula kinematics during testing compared to the intact state. The suture repair + SB construct showed increased external rotation of the fibula (p<0.001, mean 2.32 degrees) and medial translation (mean 0.72 mm, p= 0.007) or overtightening compared to the intact state. The suture repair + SB + ST augmentation state also showed increased external rotation of the fibula compared to the intact state (p<0.001). Sagittal plane motion of the fibula was not significantly different in the repair states compared to the intact state. None of the repair states restored talus rotation back to the intact state; however, the repairs that utilized suture tape reduced the talus external rotation laxity compared to the complete syndesmotic injury.Conclusion:For isolated syndesmotic injuries without significant fibular displacement, augmentation of the AITFL with suture- tape best restored the rotational profile of the fibula and ankle joint. Suture-button constructs had a tendency to over-tighten and externally rotate the fibula when compared to the intact state. Suture-tape AITFL augmentation may be a good surgical option and alternative to suture-button fixation for isolated syndesmotic disruptions. Further clinical trials are needed to determine the role for suture-tape augmentation of the AITLF in syndesmotic injuries.

Passive Proprioceptive Training Alters the Sensitivity of Muscle Spindles to Imposed Movements.

Humans rely on precise proprioceptive feedback from our muscles, which is important in both the acquisition and execution of movements, to perform daily activities. Somatosensory input from the body shapes motor learning through central processes, as demonstrated for tasks using the arm, under active (self-generated) and passive conditions. Presently, we investigated whether passive movement training of the ankle increased proprioceptive acuity (psychophysical experiment) and whether it changed the peripheral proprioceptive afferent signal (microneurography experiment). In the psychophysical experiment, the ankle of 32 healthy human participants was moved passively using pairs of ramp-and-hold movements in different directions. In a pretraining test, participants made judgements about the movement direction in a two-alternative forced choice paradigm. Participants then underwent passive movement training, but only half were cued for learning, where a reference position was signaled by a sound and the participant had to learn to recognize this position; they then completed a post-training test. In a paradigm using the same setup, nine healthy participants underwent microneurography recordings of Ia muscle afferents from the peroneal nerve, where all were cued during training. In the psychophysical experiment, proprioceptive acuity improved with training only in the cued group. In the microneurography experiment, we found that muscle afferent firing was modulated, via an increase in the dynamic index, after training. We suggest that changes in muscle afferent input from the periphery can contribute to and support central perceptual and motor learning, as shown under passive conditions using ankle movements, which may be exploited for movement rehabilitation.

Pure Obturator Dislocation of the Hip, a Rare Variety of Regular Dislocations, and Long-Term Clinical Outcomes

Introduction: Traumatic knee dislocation is considered an orthopedic emergency. Knee dislocations are relatively infrequent injuries. This injury frequently occurs from high-energy impact trauma. Neurovascular injuries can result in debilitating consequences if the diagnosis and treatment are delayed. Associated complications include degenerative arthritis, permanent neurovascular injury, and amputation. The poorest prognosis is seen in patients with knee dislocation longer than 6-8 hours before reduction. History: The 25-year-old male patient presented with a history of a road traffic accident to the emergency department. The patient presented with swelling, pain, and deformity of the left knee and leg. Examination: On examination, the patient had tense swelling and tenderness of the left knee joint and leg. Visible deformity of the left knee joint is seen. The posterior tibial artery and dorsalispedis artery were not palpable. Active ankle and toe movements were absent. Investigations: Plain radiograph was taken at the emergency department of the left knee and leg. X-rays showed anterior dislocation of the knee joint. Treatment: After valid written informed consent, the dislocated left knee joint was reduced under sedation in the operation theatre and immobilized in the above knee plaster slab. Reduction of the knee joint was done within 4 hours of injury. Then the distal pulses were re-assessed. The posterior tibial and dorsalispedis artery was absent. Hence, MR Angiography of the left lower limb was done. It showed popliteal artery transection. So, the artery was explored and end-to-end vascular anastomosis was done. A knee-spanning external fixator was applied to the left lower limb. Fasciotomy was done for the tense leg compartments. After a week, the fasciotomy wounds were infected for which extensive debridement of the wounds was done and antibiotic beads were placed. Knee was mobilized with a gradual range of motion exercises and non-weight bearing mobilization with a foot drop splint. Gradually full weight-bearing ambulation was allowed. Conclusion: Knee dislocation is rare, albeit a serious and potentially limb-threatening condition. The prognosis of knee dislocations is variable and is heavily dependent on the time interval between trauma and initiation of management. Immediate, timely, and proper management can salvage the limb, and amputation is not the only solution. Keywords: Dislocation, Posterior tibial artery, Fasciotomy

下腿部に装着する独立アーム型歩行支援装置 (基本構成の提案)

An independent arm type assist device is proposed to provide assistance to the ankle joint plantar flexion torque while being driven independently of the ankle joint motion. A structure of the device was proposed and the required specifications were determined using walking data. Based on these specifications, a redundant motor actuator for this assist device was designed with a focus on light weight and compactness. Using this actuator, a prototype of the assist device was designed, and the ankle joint plantar flexion torque assistance was investigated experimentally.

Analysis of Gait Characteristics of Patients with Knee Arthritis Based on Human Posture Estimation.

A gait feature analysis method based on AlphaPose human pose estimation fused with sample entropy is proposed to address complicated, high-cost, and time-consuming postoperative rehabilitation of patients with joint diseases. First, TensorRT was used to optimize the inference of AlphaPose, which consists of the target detection algorithm YOLOv3 and the pose estimation algorithm. It can speed up latency and throughput by about 2.5 times while maintaining the algorithm's accuracy. Second, the optimized human posture estimation algorithm AlphaPose_trt was used to process gait videos of healthy people and patients with knee arthritis. The joint point motion trajectories of the two groups were extracted, and the sample entropy algorithm quantified the joint trajectory signals for feature analysis. The experimental results showed significant differences in the entropy of the heel and ankle joint motion signals between healthy people and arthritic patients (p < 0.01), which can be used to identify patients with knee arthritis. This technique can assist doctors in determining needed postoperative joint surgery rehabilitation.

Decoding the User’s Movements Preparation From EEG Signals Using Vision Transformer Architecture

Electroencephalography (EEG) signals have a major impact on how well assistive rehabilitation devices work. These signals have become a common technique in recent studies to investigate human motion functions and behaviors. However, incorporating EEG signals to investigate motor planning or movement intention could benefit all patients who can plan motion but are unable to execute it. In this paper, the movement planning of the lower limb was investigated using EEG signal and bilateral movements were employed including dorsiflexion and plantar flexion of the right and left ankle joint movements. The proposed system uses Continuous Wavelet Transform (CWT) to generate a time–frequency (TF) map of each EEG signal in the motor cortex, and then uses the extracted images as input to a deep learning model for classification. Deep Learning (DL) models are created based on vision transformer architecture (ViT) which is the state-of-the-art of image classification and also the proposed models were compared with residual neural network (ResNet). The proposed technique reveals a significant classification performance for the multiclass problem ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> < 0.0001) where the classification accuracy was 97.33 ± 1.86 % and the F score, recall and precision were 97.32 ± 1.88 %, 97.30 ± 1.90 % and 97.36 ± 1.81 % respectively. These results shows that DL is a promising technique that can applied to investigate the user’s movements intention from EEG signals and highlight the potential of the proposed model for the development of future brain machine interface (BMI) for neurorehabilitation purposes.

The Effect of Two Resistance Training Methods on Dynamic Balance, Fall Risk, and Ankle Range of Motion in Active Elderly Women

Background and Aims Nowadays, imbalance is one of the most prevalent problems of the elderly that causes injury, disability, and reduction of independence among the elderly. The present study was conducted to investigate the impact of resistance training methods on dynamic balance, fall risk, and range of motion of ankle in active elderly women. Methods In the current quasi-experimental study, participants were 30 active elderly women (64.79±3.33) in Tehran who were randomly divided into two groups Theraband and weight training. The Y balance test evaluated dynamic balance, fall risk was assessed by the Timed up and Go test (TUG), and a goniometer evaluated ankle range of motion. Statistical analysis of data was conducted using independent and dependent t-tests (in significant level P=0.05) Results Results showed that Theraband training and weight training had a significant effect on fall risk and ankle range of motion Theraband training group was significantly superior to the weight training group in dynamic balance (P=0.001), fall risk (P=0.001), ankle range of motion (left: P=0.004 and right: P=0.001). Also, Theraband training significantly impacted dynamic balance (P=0.012). Conclusion According to the results, Theraband and weight training significantly improve the risk of falls and ankle range of motion in active elderly women. In addition, Theraband training influences dynamic balance positively. In conclusion, Theraband training affects all three research variables more than weight training.

Short-Term Efficacy and Safety of Combined Total Talus and Total Ankle Replacement

Category:Ankle; Ankle ArthritisIntroduction/Purpose:The indications for both total talus replacement (TTR) and total ankle replacement (TAR) are expanding. Combined total ankle-total talus (combined TAR) is a novel treatment option for patients with end-stage ankle arthritis and talar avascular necrosis (AVN) and patients with a prior TAR and talar component collapse. End-stage talar AVN with subchondral collapse is a challenging entity to treat. Historically, an alternative treatment option was tibiotalocalcaneal arthrodesis with structural allograft which results in fair outcomes including nonunion rates up to 40%. Combined TAR is a treatment option that theoretically maintains joint range of motion and restores anatomic alignment. The purpose of this study is to evaluate the short-term outcomes for combined TAR including pain, functional outcomes, radiographic outcomes, and complications.Methods:Consecutive patients who underwent combined TAR from 2016-2020 were retrospectively reviewed. All surgeries were performed by one of four fellowship-trained foot and ankle orthopaedic surgeons at a single academic institution. All talus implants were custom 3D printed total tali (Additive Orthopaedics, Little Silver, NJ), composed of an alloy primarily made of cobalt chrome. The implants were sized based on computed tomography scans of the contralateral talus and created to articulate with multiple TAR systems. Patient demographics, comorbidities, and surgical data were collected. Outcomes included the Visual Analog Scale (VAS) scores, radiographic alignment, range of motion, and complications. Data analysis was performed with paired t- tests and a significance level of p<0.05.Results:A total of 66 patients (67 ankles) were included with an average 12-month follow-up. There were 35 (52.2%) men, and the average age was 56.4 years old. The majority of patients (n=42, 62.7%) underwent combined TAR for talar AVN and tibiotalar arthritis while 21 (31.3%) patients were converted from an isolated TAR and 4 patients (6.0%) from an isolated TTR to combined TAR. A total of 23 (34.3%) patients had a previous talus fracture. Significant postoperative improvements compared to preoperative included: VAS (2.8 vs. 8.2; p<0.0001), ankle dorsiflexion (11.0° vs. 4.7°; p=0.0007), ankle plantarflexion (31.9° vs. 23.7°; p<0.0001), talar declination angle (20.7° vs. 11.6°; p=0.0007), Meary’s angle (2.2° vs. 10.4°; p=0.0043), and talocalcaneal height (79.6mm vs. 74.2mm; p <0.0001). There was a total of 10 (14.9%) complications, 7 (10.4%) of which required repeat surgery. There were 3 (4.5%) failures requiring explant, revision, or amputation (Table 1).Conclusion:Combined TAR is an efficacious and safe procedure. Patients experienced improvement in pain, ankle range of motion, and radiographic parameters postoperatively. This technique provides an anatomic treatment with preservation of ankle motion for patients with severely deficient bone stock due to talar AVN with ankle arthritis or failed TAR. To confirm these preliminary positive results, further studies are required including continued longer-term follow-up, prospective cohorts, and comparative analyses to other treatment options.

Prospective Radiographic Assessment of Intraoperative Range of Motion with Total Ankle Replacement

Category:Ankle ArthritisIntroduction/Purpose:One of the proposed benefits of total ankle replacement, when compared to ankle fusion is the preservation of range of motion (ROM) of the ankle. Preservation of ankle motion may improve quality of life as evidenced by patient-reported outcome measures (PROMs). However, despite improving dorsiflexion intraoperatively during TAR, studies have not demonstrated large improvements in dorsiflexion (DF) at final followup after TAR. The objective of this study was to radiographically evaluate and quantify preoperative, intraoperative ankle dorsiflexion and plantarflexion (PF), compare it to post- operative ankle ROM, and determine the effect of Achilles lengthening (TAL) on preserving dorsiflexion motion that is gained during surgery.Methods:This prospective study compared 111 patients with an average age of 62.3 years who underwent primary total ankle replacement with one of four different implants between March and December 2019. A total of 71 patients (64%) had an associated TAL based on the surgeon's decision. Intraoperative fluoroscopy was utilized by the primary surgeon to document the maximal dorsiflexion and plantar flexion at the end of the case. This was completed after the TAL on a perfect lateral.Standardized weight bearing at maximum ROM positions lateral radiographs were obtained twelve months postoperatively. The change in range of motion was analyzed using a paired t-test with a significance level of 0.05.Results:The cohort's preoperative range was 22.0° (8.1°DF, 14°PF) and was increased to 38.5° intraoperatively (12.7°DF, 25.8°PF) as described in Table 1. Postoperative ROM is 24.9° (11.7°DF, 13.2°PF) which means that 65% of the intraoperative ROM is preserved. Preoperative and intraoperative range of motion was not different between the group that had a TAL compared to no TAL. At the year postoperatively, the dorsiflexion was similar between both groups. The group who did not have a TAL went from 12.8 intraoperatively to 12.2° postoperatively whereas the group who had a TAL went from 12.2° to 11.3° which was statistically equivalent.Conclusion:This study is the first to assess how much ankle range of motion is retained after TAR. Overall, we observed that 65% of dorsiflexion was retained after TAR. TAL as a concomitant procedure did not effect the proportion of dorsiflexion motion that was retained. Additional studies are needed to determine how to best optimize and increase ROM after TAR.

Motion is Maintained at the Tibial and Polyethylene Component Interface in a Mobile-Bearing Total Ankle Arthroplasty at Mid and Long-Term Follow-Up

Category:Ankle Arthritis; Ankle; HindfootIntroduction/Purpose:Normal biomechanics of the ankle joint includes sagittal motion, but also anterior-posterior (AP) translation (1mm) as well as axial rotation (5-8 degrees). Sagittal motion is well described in total ankle arthroplasty (TAA), however, current understanding of mobile-bearing motion at the tibial-polyethylene interface in TAA is limited to AP motion and short-term data on axial rotation. The purpose of our study was to determine if polyethylene components maintain mobility adjacent to the tibial component in mobile bearing TAA at mid and long-term follow-up in both the sagittal and axial planes in patients more than 48 months post-operatively.Methods:Patients who were a minimum of 48 months postoperative from a third-generation mobile-bearing TAAwere identified. Fluoroscopic images perpendicular to the tibial component were saved at maximum internal and external rotation on AP, and the lateral images were saved in maximum plantarflexion and dorsiflexion. Sagittal range of motion and AP translation of the polyethylene component were measured from the lateral images. Axial rotation was determined by measuring the relative position of the two wires within the polyethylene component on AP internal and external rotation imaging. This relationship was compared to a table previously developed from fluoroscopic images taken at standardized degrees of axial rotation of a nonimplanted polyethylene with the associated length relationship of the two imbedded wires. Total axial motion was determined by the difference between angle value determined for maximum internal and external rotation.Results:Eight patients were included in this investigation, 5 (62.5%) were female and average age was 72.6 (range, 59-83) years. Time from surgery averaged 94.2 (range, 54.7-118.6) months. Total sagittal range of motion between the talar and the polyethylene component averaged 20.3 (range, 10-30) degrees. All patients (100%) maintained motion at the tibia-polyethylene interface. Axial motion for total internal and external rotation of the polyethylene component articulation on the tibial component averaged 5.3 (range, 2-12) degrees. AP translation of the polyethylene component relative to the tibial component averaged 1.1 (range, 0.4-2.6) mm during plantarflexion and dorsiflexion. There was no relationship between axial rotation or AP translation of the polyethylene component and ankle joint range of motion (P >.05).Conclusion:To our knowledge, this is the first investigation to measure axial and sagittal motion of the polyethylene component in mobile bearing TAA at the tibial implant interface in patients at mid and long-term follow-up. Based on our results, motion is maintained an average of 8 years post-operatively and concludes that a mobile-bearing TAA has the potential to fall within the parameters of normal polyaxial ankle motion several years after implantation. Such maintenance of motion may have a positive influence on gait pattern, polyethylene wear, joint reaction forces and implant longevity.

Anterior Capsule Reconstruction in the Setting of PVNS

Category:Ankle; OtherIntroduction/Purpose:Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disease affecting tendon sheaths and synovial tissue. Most cases of PVNS arise in the hip and knee joints, while < 5% of total cases occur in the foot and ankle. PVNS of the ankle has a high rate of recurrence and can be destructive to the affected joints if incompletely removed. This case series analyzes functional outcomes after PVNS surgical resection and anterior ankle capsular reconstruction, using a novel technique.Methods:This case series included three patients who underwent surgery between 2010 and 2020 for their ankle pain and swelling caused by PVNS. The surgical technique involved a posterior, midline approach for PVNS resection of the affected ankle joint, followed by a standard anterior approach for capsular excision. Subsequent anterior capsular reconstruction was performed with a regenerative tissue matrix and a bioresorbable anchoring system. Preoperative and postoperative range of motion testing for the ankle and subtalar joints were assessed along with appropriate radiographs and MRI imaging.Results:All three surgical procedures for PVNS of the ankle resulted in successful recovery and promising clinical outcomes. The mean cohort age was 43.7 (R:36-58) years and follow-up period was 52.3 (R:4-123) months. Preoperative ankle dorsiflexion and plantarflexion along with subtalar inversion and eversion range of motion were all normal. Postoperative ankle motion and subtalar motion were recorded at final follow up and found to be unchanged. No complications or recurrence of PVNS occurred.Conclusion:This case series demonstrates that PVNS surgical resection and anterior ankle capsular reconstruction is a safe and effective treatment modality that allows for maintenance of pre-operative motion. Further investigation is warranted to better understand the clinical outcomes of this surgical technique on PVNS recurrence.

Total Talus Replacement with Subtalar Arthrodesis for End-Stage Talar Osteonecrosis and Adjacent Joint Arthritis

Category:Ankle; Hindfoot; Trauma; OtherIntroduction/Purpose:Late stage talar avascular necrosis (AVN) results in devascularization of the talus with osteonecrosis, subchondral collapse, talus fracturing, loss of talar height and declination, and adjacent joint arthritis. This results in significant disability for patients with limited treatment options. Tibiotalocalcaneal arthrodesis with structural allograft has been the historic treatment option for this challenging clinical scenario, however, the outcomes are fair with reported nonunion rate up to 40%. Total talus replacement (TTR) is an emerging treatment option for patients with talar AVN. TTR with subtalar arthrodesis may be utilized for end-stage talar AVN with adjacent joint arthritis. The purpose of this study is to evaluate the short-term outcomes for TTR with subtalar arthrodesis including pain, ankle range of motion, union rates, and complications.Methods:Consecutive patients who underwent TTR with a subtalar arthrodesis from 2016-2020 were retrospectively reviewed. All surgeries were performed by one of two fellowship-trained foot and ankle orthopaedic surgeons at a single academic institution. All talus implants were custom 3D printed total tali (Additive Orthopaedics, Little Silver, NJ), composed of a cobalt chrome alloy. The implants were sized based on computed tomography scans of the contralateral talus. The plantar surface of the tali were prepared with an ingrowth surface and drill holes to accept screws and facilitate subtalar arthrodesis. Patient demographics, comorbidities, and surgical data were collected. Outcomes included the Visual Analog Scale (VAS) scores, range of motion, union rates, and complications. Data analysis was performed with paired t-tests and a significance level of p<0.05.Results:A total of 19 patients were included with an average of 11.4 months follow-up. There were 11 (57.9%) men, and the average age was 52.3 (range, 18-75) years-old. About half (n=9, 47.4%) of the cohort had a previous talus fracture, and 17 (89.5%) patients had previous ipsilateral ankle surgery. There were 5 (26.3%) patients who underwent concomitant talonavicular arthrodesis at the time of TTR and subtalar arthrodesis. Significant postoperative improvements were observed in VAS scores (2.4 vs. 8.6; p<0.0001), ankle dorsiflexion (10.7° vs. 1.8°; p=0.0131), and ankle plantarflexion (32.9° vs. 21.3°; p<0.0068). All patients achieved a successful union of their subtalar arthrodesis (n=19/19, 100%) and talonavicular arthrodesis (n=5/5, 100%). There were 2 (10.5%) complications including 1 (5.3%) delayed wound healing successfully treated nonoperatively and 1 (5.3%) reoperation in a patient with persistent varus ankle deformity requiring distal tibia and fibula osteotomies. There were no postoperative infections, explants, or amputations required.Conclusion:TTR with subtalar arthrodesis should be considered as a treatment option for patients with end-stage talar AVN and adjacent joint arthritis. Patients experienced significant improvement in pain and ankle range of motion. The complication rate was 10.5% with only 1 patient requiring a reoperation. A union rate of 100% was observed with no postoperative infections, explants, or amputations. This technique perves ankle motion while eliminating hindfoot pain in patients with loss of talar bony integrity and adjacent joint arthritis. Further studies are required including longer-term follow-up and prospective cohorts to ensure continued safety and efficacy.

Anatomical Tenodesis Reconstruction Using Free Split Peroneal Brevis Tendon for Severe Chronic Lateral Ankle Instability.

Many operative procedures have been reported for the management of chronic lateral ankle instability, and anatomical reconstructions are an excellent option. However, if the remnants of the ligaments are considerably damaged, anatomical reconstructions using such remnants can be difficult. In cases such as these, tenodesis stabilization may be required. However, tenodesis stabilization often restricts the range of ankle movement. The purpose of this study was to determine the effectiveness of a new procedure that we developed to mitigate the problems associated with tenodesis stabilization procedures. We installed grafts in the original anatomical position by devising a system for positioning the drill holes in the bones so that our procedure did not restrict the range of ankle movement. A retrospective review of 37 patients (13 men, 24 women) with a mean age of 30.2 (range, 16-66) years was performed at an average of 69 (range, 47-77) months after the surgery. The average American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved significantly from 65.6 (range, 47-77) points preoperatively to 98.0 (range, 87-100) points postoperatively (P < 0.001). With the number of subjects available, no significant differences were detected between the postoperative mean ranges of movement of the ankle and subtalar joints and those of the preoperative ankle. Patients who underwent anatomical tenodesis reconstructions with a free split peroneal brevis tendon showed good outcomes after a 69-month follow-up period.

Lower-Limb Motion-Based Ankle-Foot Movement Classification Using 2D-CNN

Recently, the Muscle-Computer Interface (MCI) has been extensively popular for employing Electromyography (EMG) signals to help the development of various assistive devices. However, few studies have focused on ankle foot movement classification considering EMG signals at limb position. This work proposes a new framework considering two EMG signals at a lower-limb position to classify the ankle movement characteristics based on normal walking cycles. For this purpose, we introduce a human ankle-foot movement classification method using a two-dimensional-convolutional neural network (2D-CNN) with low-cost EMG sensors based on lower-limb motion. The time-domain signals of EMG obtained from two sensors belonging to Dorsiflexion, Neutral-position, and Plantarflexion are firstly converted into time-frequency spectrograms by short-time Fourier transform. Afterward, the spectrograms of the three ankle-foot movement types are used as input to the 2D-CNN such that the EMG foot movement types are finally classified. For the evaluation phase, the proposed method is investigated using the healthy volunteer for 5-fold cross-validation, and the accuracy is used as a standard evaluation. The results demonstrate that our approach provides an average accuracy of 99.34%. This exhibits the usefulness of 2D-CNN with low-cost EMG sensors in terms of ankle-foot movement classification at limb position, which offers feasibility for walking. However, the obtained EMG signal is not directly considered at the ankle position.

Treatment of chronic lateral ankle instability by double-band anatomical reconstruction of the anterior talofibular ligament's fibular enthesis.

Anterior talofibular ligament (ATFL) injury is one of the most common injuries in sports medicine, resulting in chronic lateral ankle instability (CLAI). The patients' daily life may be seriously affected by ankle osteoarthritis and other irreversible damages, if the ATFL injury is not treated in time and drags on. Patients with ATFL injury who show no significant recovery after 3-6 months of conservative treatment should consider surgical treatment as soon as possible to restore ankle stability and function. This study aims to investigate the effect of double-bands anatomical reconstruction of the ATFL's fibular enthesis for the treatment of CLAI. A retrospective review was conducted on 67 patients diagnosed with CLAI in the Department of Sports Medicine, Xiangya Hospital, Central South University from January 2015 to January 2018, including 42 males and 25 females, aged from 17 to 41 years old, with disease course of (12.6±3.2) months. Of the 67 patients, 29 left ankles and 38 right ankles were included in this study. Patients suffered from repeated sprains which leaded to pain, swelling and obvious ankle relaxation. There were obvious tenderness at the ATFL insertion and the calcaneal fibular ligament insertion. Both the anterior ankle drawer test and the varus stress test were positive. Other ankle disorders were excluded by X-ray. Preoperative color Doppler ultrasonography and magnetic resonance examination were performed to observe ATFL injury. All the patients had surgical indications and no obvious contraindications, and they were treated with arthroscopic debridement and double-bundle anatomical reconstruction of the AFTL's fibular enthesis under anesthesia. Postoperative routine nursing and standardized rehabilitation exercise were recommended. Outpatient follow-up was conducted at 3, 6, 12, and 24 months postoperatively. American Orthopaedic Foot and Ankle Society (AOFAS) scores, Karlsson Ankle Functional (KAF) score, and the Japanese Society for Surgery of the Foot (JSSF) scale were used to evaluate the clinical outcomes. Intraoperative arthroscopic examination of 67 patients showed inflammatory synovial hyperplasia in 52 cases (77.6%), obvious osteophyte hyperplasia in 12 cases (17.9%), talus osteochondral injury of grade II-III in 23 cases (34.3%), and cartilage injury of grade IV in 5 cases (7.5%). All operations were carried out successfully, and both the anterior ankle drawer test and the varus stress test were negative under anesthesia after surgery. The anchors were in good position. Among them, 3 patients (4.5%) got temporary superficial peroneal nerve palsy and skin numbness at ankle joint after surgery, which gradually recovered within 2 weeks. There were no serious perioperative complications such as infection and suppurative arthritis. Postoperative follow-up was conducted for 12-24 (15.64±3.17) months. At the last follow-up, all patients were walking normally. Most patients had no pain or occasionally mild pain. Ankle function and motion were restored without re-instability. Sixty-four patients (95.5%) worked and exercised as before the surgery. Standing X-ray examination indicated normal joint space without stenosis, and the internal fixation was in good position. Postoperative AOFAS scores (94.78±6.37) were significantly better than the preoperative scores (64.17±12.43, P<0.01). Besides, the KAF scores and the JSSF ankle/hindfoot scale before surgery were significantly increased (KAF: 91.04±11.36 vs 59.74±13.63, P<0.01; JSSF: 95.32±10.21 vs 66.92±14.38, P<0.01). Arthroscopic debridement and double-bands anatomical reconstruction of the ATFL's fibular enthesis for the treatment of CLAI gains beneficial short-term effects for its minimal invasion and quick recovery.

The effect of an ankle-foot orthosis on tibiofemoral motion during step-up and step-down in healthy adults.

Solid ankle-foot orthoses (SAFOs) are frequently prescribed in conditions such as cerebral palsy and stroke. Although gait is improved in the short term, long-term effects of limiting ankle and foot motion during functional activities on joints such as the knee have not been investigated. Our study purpose was to compare tibiofemoral (TF) motion in shoe and SAFO conditions in healthy adults to inform future studies in clinical populations. A custom-made device using electromagnetic sensors was used to collect three-dimensional TF rotation data while 29 healthy adult participants (female participants = 19, age = 24.4 ± 4.5 years) performed step-up/step-down in shoe and SAFO conditions. In the SAFO condition during step-up, extent of motion was greater in frontal and transverse planes and less in the sagittal plane. Discrete values at 0%-10% of the cycle in sagittal, 50%-100% in frontal, and 40%-100% in transverse planes were statistically different, producing more abduction and external rotation. In the SAFO condition during step-down, extent of motion was significantly greater in the frontal and transverse planes. Discrete values were statistically different in 40%-60% of the cycle in sagittal, 0%-30% and 70%-90% in frontal, and 0%-30% and 70%-90% in transverse planes, producing more abduction and external rotation in the first half of the cycle and more adduction and internal rotation in the second half of the cycle. An SAFO affects triplanar TF kinematics in healthy adults during step-up/step-down. Future investigations into ankle-foot orthosis prescription and TF motion in clinical populations will facilitate optimal ankle-foot orthosis prescription and knee function in the long term.

Protection by Ankle Brace for Lower-Extremity Joints in Half-Squat Parachuting Landing With a Backpack

Half-squat parachuting landing is a kind of activity with high impact force. Injuries on lower-extremity joints are common in half-squat parachuting landing and would be increased with a backpack. An ankle brace was used to prevent ankle injuries in landing. However, few quantitative studies reported about the protection of an ankle brace for lower-extremity joints in half-squat parachuting landing with a backpack. This study focused on evaluating the protective effects of an ankle brace in half-squat parachuting landing with a backpack. Seven male participants landed from 120 cm with a backpack and an ankle brace. Each participant performed three landing trials on every experimental condition. Kinetics and kinematics of the hip, knee, and ankle were analyzed. It was found that the ankle brace did not significantly affect the ground reaction force with backpack but increased the ground reaction force from 14.7 ± 2.0 bodyweight to 16.2 ± 1.9 bodyweight (p = 0.017) without the backpack. The ankle brace significantly (p < 0.05) decreased the angular displacement, angular velocity, and angular acceleration of the ankle both without and with the backpack. In conclusion, the ankle brace could restrict ankle motion and significantly increase ground reaction force without the backpack. However, the ankle brace did not significantly influence ground reaction force and still restricted ankle motion with the backpack. Therefore, the ankle brace was more effective in half-squat parachuting landing with the backpack than no-backpack landing.