Normal Ankle Research Articles

Design Rational for Total Ankle Arthroplasty: An Update

The design of total ankle arthroplasty (TAA) systems is rapidly evolving as device companies try to keep pace with the expansion of surgical indications and a refinement of techniques for TAA. Even since the publication of the latest “update,” published in 2018, three new designs and three updates on preexisting third-generation implants came onto the market. Improvements in third-generation TAA systems include minimal bone resection, retaining ligamentous support, and anatomic balancing. Fourth-generation systems use 3D printing technology, improved talus and tibia designs based on CT scans of arthritic and normal ankles, and include patient-specific instrumentation. We will then explore the short-term and mid-term outcomes of the previously discussed six TAA systems—INBONE, INFINITY, INVISION (Stryker), Salto-Talaris (Smith and Nephew), Scandinavian Total Ankle Arthroplasty (Enovis), Trabecular Metal Total Ankle (Zimmer Biomet), and VANTAGE (Exactech). As more research pours in regarding mid- to long-term outcomes of these implants, it is important to assess the design rationale and summarize current outcome data for these implants.

Functional Outcomes of Immediate Weightbearing After Arthroscopic Lateral Ankle Ligament Repair: A Prospective Randomized Single-Center Trial.

Previous studies have revealed that early postoperative rehabilitation of chronic lateral ankle instability is just as crucial as surgical intervention. Immediate weightbearing has yielded good clinical results; however, randomized controlled studies have been limited. To compare the clinical outcomes of patients with immediate weightbearing after lateral ankle ligament repair with those with delayed weightbearing after 2 weeks in a prospective randomized controlled study. Randomized controlled clinical trial; Level of evidence, 1. Patients who underwent arthroscopic anterior talofibular ligament repair between August 2021 and December 2022 were randomized into 2 groups-immediate weightbearing with a hard ankle brace and nonweightbearing casting for 2 weeks followed by cast removal and weightbearing. Primary outcomes were the ankle function scores as assessed using the visual analog scale at rest and during activities, the American Orthopaedic Foot & Ankle Society (AOFAS) score, and the Karlsson Ankle Functional Score (Karlsson score). Secondary outcomes were the time to return to unsupported walking, jogging, work, and exercise and change in the ankle range of motion (ROM) at 3-, 6-, and 12-month follow-ups. A total of 88 participants were included, consisting of 58 men and 30 women, with a mean age of 30.26 years. Computerized randomization resulted in 44 patients per group. These 2 groups displayed no difference in the AOFAS score, Karlsson score, and ankle ROM at all follow-ups. Patients who underwent immediate weightbearing had a significantly shorter time of returning to unsupported walking (P < .001). No differences were observed in the time of returning to work, jogging, and sports exercise. For patients with chronic ankle instability after arthroscopic anterior talofibular ligament repair, immediate weightbearing allowed patients to return to unsupported walking more quickly and had no negative effects on the AOFAS score, Karlsson score, times of returning to normal life, jogging, sports exercise, and ankle ROM at 3-, 6-, and 12-month follow-ups compared with cast fixation. ChiCTR2100049612 (Chinese Clinical Trial Registry; https://www.chictr.org.cn/).

Functional outcomes in anterior talofibular ligament repair with anchoring screw: Two case series

Background: The Anterior Talofibular Ligament (ATFL) functions to resist plantarflexion and anterolateral translation of the talus. Lateral ankle sprains account for 85% of all ankle sprains and are most common in athletes. ATFL injury is the most common ankle ligament injury, accounting for 35.6% of the total patients with ligament injuries. Case Report: The first patient, a 39 year old man with a diagnosis of ATFL injury, had a history of falling with the outside of his right leg supported when he fell. Physical examination of the right ankle revealed tenderness in the posterolateral region, pain during dorsiflexion and plantarflexion, positive anterior drawer examination and positive talar tilt. The second patient, a 19 year old male with the same history and injury location on the right ankle. Physical examination showed a similar condition to the first patient. MRI examination of both patients showed ATFL injury. Both patients underwent open repair of the right ATFL (Brostrom technique) with anchoring screws, post-operative care, and evaluation one year after surgery. Discussion: Surgery is taken to prevent repeated ruptures, especially in cases of ligament tears. The Brostrom technique is an anatomical repair with end-to-end repair from the final ATFL tear to the distal anterior fibula. Both patients demonstrated normal foot and ankle function, with a score of 100 based on the American Orthopedic Foot Ankle Association (AOFAS). Conclussion : Brostrom open repair with Anchoring Screw is an effective procedure in returning the patient's function to its previous level as assessed based on the AOFAS score after a year after surgery.

7796 The Profile And Associated Risk Factors Of Diabetic Foot Disease Among Patients With Type 2 Diabetes Mellitus Seen At Outpatient Clinics In A Tertiary Private Hospital In Quezon City, Philippines

Abstract Disclosure: D.C. Lopez: None. K.T. Lim: None. B.C. S.: None. O.C. Dampil: None. The Profile and Associated Risk Factors of Diabetic Foot Disease Among Patients with Type 2 Diabetes Mellitus Seen at Outpatient Clinics in a Tertiary Private Hospital in Manila, Philippines. Background: Diabetic foot disease is a debilitating complication of diabetes mellitus and is a major source of morbidity, mortality, and reduced quality of life. Determining the risk factors of diabetic foot ulcer is important to prevent the devastating consequences among patients with diabetes. This study aims to determine the profile and associated risk factors of diabetic foot disease among patients diagnosed with type 2 diabetes mellitus being seen in private specialty clinics. Methodology: A single center, analytical cross-sectional study was conducted among patients with type 2 diabetes mellitus at outpatient clinics in a tertiary private hospital in the Philippines. Clinical information and laboratory results were obtained during the time of consult; and patients were classified as either low risk, moderate risk, high risk for diabetic foot disease or in active foot disease. Interaction between various risk factors was explored by multivariate analysis. Results: A total of 129 adult patients with diabetes mellitus were evaluated using the Diabetes Foot Screening and Risk Stratification Tool from January to May 2021. The demographic and clinical profile of the study showed that proportion of patients with neuropathy (χ2=60.66, p=0.001), long duration of diabetes (F=5.92, p=0.004), and low estimated glomerular filtration rate (eGFR) (F=3.70, p=0.023) was significantly higher in patients with moderate to high risk for diabetic foot disease. Univariate polynomial logistic regression analyses showed that neuropathy greatly increased the odds of having moderate (OR=115.63, p=0.001) and high risk stratification (OR=166.50, p=0.001). Other factors were also noted to affect the risk stratification for diabetic foot disease such as duration of diabetes (OR=1.09, p=0.004) and hypertension (OR=2.45, p=0.027). On the other hand, normal eGFR (OR=–1.02, p=0.011), left normal ankle brachial pressure index (OR=–4.32, p=0.042), and good glycemic control (OR=–5.41, p=0.050) significantly decrease the likelihood of having high risk stratification for diabetic patients. Conclusion: Those most susceptible to developing high risk for diabetic foot disease were patients with neuropathy, hypertension, and long duration of diabetes. High-risk patients with the given profile should be followed closely in order to prevent complications brought by diabetes. Keywords:Diabetes mellitus, Diabetic foot disease, Foot ulcer Presentation: 6/3/2024

Cross-Screw Fixation in Isolated Medial Malleolar Fractures.

Isolated medial malleolar fractures are observed less often than are lateral malleolar fractures, bimalleolar fractures, and trimalleolar fractures. The aim of treatment is to provide anatomical reduction, protect this reduction until the fracture heals, and to regain normal ankle function. The aim of our study was to evaluate the clinical and radiological outcomes of patients with isolated medial malleolus fracture treated with cross-screw fixation. The study included 13 patients: 9 males with a mean age of 37.1 years (range, 25-64 years) and 4 females with a mean age of 40.2 years (range, 24-62 years) who were treated with the cross-screw fixation method for an isolated medial malleolar fracture. The fracture union status was evaluated on the 3-month postoperative radiographs, and the functional outcomes with the American Orthopaedic Foot and Ankle Scale (AOFAS) ankle score. The mean AOFAS score was 82 at 3 months postoperatively, evaluated as an excellent outcome in 2 patients, good in 9, and fair in 2. At the 24th month postoperatively, the mean AOFAS score was determined to be 92.2, evaluated as excellent in 11 patients and good in 2. On palpation of the medial malleolus, the mean VAS pain score was 2 (range, 1-3.8) at 3 months postoperatively, and a mean of 0.6 (range, 0.2-3) at 24 months. Cross-screw fixation can be preferred for the fixation of isolated medial malleolar fractures as it causes less soft-tissue damage because it can be performed percutaneously, and the screw head has a low profile, thereby eliminating the need for a Kirschner wire to be applied together with the screw to prevent rotational deformity.

Preoperative planning of total ankle prosthesis – What are we aiming at?

IntroductionAnkle osteoarthritis poses significant challenges, affecting patients’ quality of life and often necessitating surgical intervention. Total ankle replacement (TAR) has emerged as an effective treatment, in patients with post-traumatic arthritis. Precise preoperative planning is crucial for achieving optimal outcomes in TAR procedures. This article explores the use of advanced imaging techniques, virtual modeling, and surgical strategies in preoperative planning for TAR. MethodsThe preoperative planning process involves thorough patient assessment, including clinical examination and imaging studies such as Weight Bearing CT scans (WBCT) and MRI. Classification systems like the Canadian Orthopedic Foot & Ankle Society (COFAS) classification help guide treatment decisions and staging of procedures. Virtual foot/ankle models derived from WBCT scans enable accurate assessment of deformities and facilitate precise implant positioning. DiscussionOptimal TAR outcomes rely on restoring normal ankle anatomy and function while addressing associated deformities and pathology. Precise alignment, joint congruency, and rotational positioning of implant components are Important considerations. Virtual planning allows for simulation of implant placement and axis correction, aiding surgical decision-making and predicting outcomes. However, it has limitations in predicting soft tissue effects and final implant size. ConclusionPreoperative planning plays a important role in TAR procedures, understanding optimal implant placement. Advanced imaging modalities, classification systems, and virtual modeling techniques enhance surgical precision. Continued refinement of preoperative planning strategies is essential for further advancing TAR outcomes and patient satisfaction.10.1016/j.fuspru.2024.07.001

Open total talus dislocation without concomitant malleoli fracture: a case report

BackgroundTotal talus dislocation without ankle (malleoli) fracture is a very rare injury with prevalence of only 0.06% of all dislocations and only 2% of talar injuries, and are usually associated with common complications such as infection, avascular necrosis, and posttraumatic arthritis. The treatment usually involves debridement, reduction, stabilization of the ankle joint, and primary or secondary closure of the wound.Case presentationWe present the case of a 40-year-old South Asian woman who was involved in an accident. She was rushed to our hospital, whereby subsequent examination revealed an open total talus dislocation with the talus being exposed in its entirety from a contaminated wound in the medial side. Furthermore, radiograph confirmed total talus dislocation without concomitant malleoli fracture. She was immediately taken to the operating theater whereby debridement and immediate reduction was performed under anesthesia, and the ankle was stabilized with external fixator for about 6 weeks. She is now able to bear weight on the affected ankle with minimal tolerable pain and has normal range of motion of the ankle.ConclusionsOpen total talus dislocation without concomitant malleoli fracture is a rare injury. Reduction of the talus in combination with complete wound debridement potentially successfully avoids infection, provides early revascularization preventing avascular necrosis, and preserves the normal ankle anatomy.

Patient-specific modelling of contact characteristics in the ankle joint following triple arthrodesis in valgus, neutral and varus hindfoot positions

The aim of the current study was to understand the importance of the joint alignment following triple arthrodesis by analysing the contact characteristics in a normal and arthritic ankle joint using a patient-specific numerical model developed using open source software. The alignment of the hindfoot with respect to tibia is calculated from CT scans and the ankle joint model was numerically analysed for neutral, valgus and varus positions in both normal and arthritic conditions. The contact area, the magnitude and distribution of the contact pressure on the articular surface of the talar dome was evaluated using a cell-centred Finite Volume Method implemented in open-source software OpenFOAM. It was found that all positions of the hindfoot predict higher lateral pressures during heel strike. The varus position predicts the maximum increase in lateral pressures. Comparing the valgus and neutral positions, although the neutral position predicts 9.1 % higher increase in lateral pressures during heel strike than valgus, it predicts 33.6 % decrease in pressures during heel-rise and the distribution is more medial during toe-off. In the case of arthritic ankle, it could be observed that the neutral and varus hindfoot fusion positions result in a concentrated increase of lateral pressures in heel strike and flat-foot. In the case of toe-off, the neutral alignment results in an increase of 62.3 % in the contact pressures compared to the arthritic pressure of the unfused foot and is 20.8 % higher than the valgus alignment. The study helps to conclude that the fusion is more beneficial at the neutral position of the hindfoot for the patient specific ankle. However, the 5° valgus position of hindfoot alignment could be more beneficial in the arthritic ankle. Patient-specific approach to the placement of the hindfoot with the help of numerical analysis could help address the issue of ankle degradation following arthrodesis.

Computed tomography-based morphometric analysis of normal distal tibiofibular syndesmosis in the Indian population

BackgroundIn suspected Ankle Instability, the parameters that can be defined in the X-ray have their limitation owing to their variability in positioning and rotation of the tibiofibular joint. This inaccuracy further increases due to variability in morphometric parameters of distal tibiofibular syndesmosis among different populations based on race and sex. This research aims to study morphometry of normal distal tibiofibular syndesmosis based on computed tomography imaging in the Indian population. MethodsAn Prospective observational study was performed from December 2020 to October 2022 on normal ankle CT scans of 100 Indian population using axial, sagittal, and coronal CT images. Anterior and posterior tibiofibular distance, Morphology of the incisura fibularis based on depth, Tibiofibular clear space (TFCS) and tibiofibular overlap (TFO), Transverse and longitudinal length of the fibula, and Relationship between the center of the talus and the center of a line joining the outer aspect of malleoli in the coronal plane were measured and analyzed by two different observers. ResultsOut of the 100 participants, 77 (77 %) were male, and 23 (23 %) were female. The overall mean age of participants was 34.69 ± 9.7 years. The incisura fibularis was concave in 54 %, and shallow in 46 %. Anterior tibiofibular distance, Posterior tibiofibular distance, and Tibiofibular overlap were significantly different in comparison to the male with female populations (p-value < 0.05). ConclusionThis study gives the indices that describe normal variations in the anatomical relationship between the fibula and fibular incisure in the Indian population, which will be helpful for improving the diagnostic accuracy of distal tibiofibular syndesmoses and providing optimal treatment in order to improve functional outcomes and reduce the risk of complications. Level of EvidenceIII.

Biomechanical Effects of Hindfoot Alignment in Supination External Rotation Malleolar Fractures: A Human Cadaveric Model.

Pressure distribution in the ankle joint is known to be dependent on various factors, including hindfoot alignment. We seek to evaluate how hindfoot alignment affects contact pressures in the ankle joint in the setting of supination external rotation (SER) type ankle fractures. SER fractures were created in 10 human cadaver lower extremity specimens, simulating progressive stages of injury: without fracture (step 0), SER fracture and intact deltoid ligament (step 1), superficial deltoid ligament disruption (step 2), and deep deltoid ligament disruption (step 3). At each step, varus and valgus alignment was simulated by displacing the calcaneal tuberosity 7 mm medial or lateral. Each limb was axially loaded following each osteotomy at a static load of 350 N. The center of force (COF), contact area (CA), and peak contact pressure (PP) under load were measured, and radiographs of the ankle mortise were taken to analyze the medial clear space (MCS) and talar tilt (TT). The COF (5.3 mm, P = .030) and the CA (-188.4 mm2, P = .015) changed in step 3 in the valgus hindfoot alignment compared to baseline parameters, indicating the importance of deep deltoid ligament integrity in maintaining normal ankle joint contact stress in the valgus hindfoot. These changes were not seen in the setting of varus alignment (COF: 2.3 mm, P = .059; CA -121 mm2, P = .133). PP were found to not change significantly in either varus or valgus (varus: -4.9 N, P = .132; valgus: -4 N, P = .464).The MCS demonstrated widening in step 3 compared to step 2 (0.7 mm, P = .020) in both varus and valgus hindfoot. The TT increased significantly in step 3 in the valgus hindfoot (2.8 degrees, P = .020) compared to step 0. SER-IV fractures with valgus hindfoot alignment showed significant changes in pressure distribution and radiographic parameters when compared to SER-IV fractures with varus hindfoot alignment. Based on this cadaver modeling study, patients with SERIV fracture with varus hindfoot alignment and complete deltoid ligament lesion may not need fracture fixation, whereas those with valgus hindfoot alignment likely need fracture fixation.

Pressure change at ankle joint in supramalleolar osteotomy with or without fibular osteotomy according to different types of varus ankle.

The need for additional fibular osteotomy (FO) when performing supramalleolar osteotomy (SMO) in the varus ankle arthritis (VAA) is controversial. Some cadaveric studies have been performed to prove this; however, it is difficult to implement deformities including talar tilting and translation in cadavers. In this study, we created a model of VAA with the tilting and translation using three-dimensional (3-D) finite element (FE) analysis and analyzed the results of SMO with or without FO depending on the types of VAA. The validated normal foot and ankle 3-D FE model was constructed including the ankle cartilages of the talar dome and tibia plafond. The VAA models were determined and reconstructed by following the classification of VAA, VAA with medial translation for stage 3a, VAA with varus tilting (7.5°) for stage 3b. The postoperative SMO models (SMO with and without FO) were reconstructed by corresponding to each VAA models. The FE analysis conditions were commonly applied. The boundary condition of ankle joint was defined as "sliding condition"and applied 0.002 friction coefficient to realize lubricative property. Loading condition was assumed as a two-leg standing position and half of the subject body weight (325 N) was loaded on center of ground to vertical direction. Contact pressure changes were predicted at the medial ankle cartilage. As a result, in VAA with medial translation, isolated SMO may provide sufficient pressure reduction at the medial ankle joint. However, in VAA with varus tilting, SMO combined with FO could appropriately relieve concentrated pressure at the medial ankle joint.

Cluster Analysis of Normal Ankle Joint X-ray Morphology of Han Adults in Shaanxi Province, China

Cluster Analysis of Normal Ankle Joint X-ray Morphology of Han Adults in Shaanxi Province, China

Anthropometric evaluation of side, sex and age by radiological examination of the normal ankle joint among adult Egyptian population

PurposeSex and age estimation is important, particularly when information about the deceased is unavailable. There are limited radiological studies investigating side, sex and age differences in normal ankle morphometric parameters. The authors’ goal was to evaluate different ankle joint morphometric measurements and document variations among Egyptians.Design/methodology/approachA prospective study was conducted throughout 23 months on 203 (100 males and 103 females) adult Egyptians, aged between 20-69 years old, who were referred for a plain x-ray of bilateral normal ankle joints.FindingsAnkle parameters showed no statistical difference between both sides, except for tarsal width (TaW) which was significantly higher on right than left side (26.92 ± 2.66 vs 26.18 ± 2.65 mm). Males showed significantly higher morphometric values except for anteroposterior gap (APG) and talus height (TaH) which were significantly higher in females (2.29 ± 0.80 vs 1.80 ± 0.61 mm and 13.01 ± 1.68 vs 11.87 ± 1.91 mm, respectively). There was significant increase in tibial arc length, APG, distance of level of MTiTh from anterior limit of mortise, distance of level of MTiTh from vertex of mortise, sagittal distance between tibial and talar vertices and sagittal radius of trochlea tali arc in old age group compared to young one. A significant decrease in tibial width, malleolar width, TaW and TaH was noted in old age group compared to young one.Originality/valueAnkle joints of both sides are mostly symmetrical; however, there are significant differences in most morphometric values due to sex and age factors. These findings may be essential during side, sex and age determination.

An AI-based ambulatory ankle brace with wearable sensor used for preventing ankle sprains

Ankle sprain is one of the most common injuries in the game of basketball. The ankle sprain may bring tremendous time and cost loss, and patients with a history of ankle sprain are susceptible to further ankle injuries. This paper proposes an AI-based ambulatory ankle brace with wearable sensors that can be used for ankle-sprain prevention. The equipment consists a sensor, a microcomputer, a Bluetooth module, and a muscle stimulator. Ten volunteers performed twelve basketball moves with the ankle brace on, and the twelve basketball moves were labeled as high-risk and low-risk. The sensor on the ankle brace measured the 3-dimensional angular velocity and angular displacement of the subjects ankle in real-time, and the data were then fed to different machine learning algorithms to create models to predict future ankle motions. The model with the best performance created by the Random Forest algorithm was imported into the microcomputer. Once the model predicts a high-risk move, the microcomputer sends a Bluetooth signal to the muscle stimulator. The one end of the stimulator is a pair of electrodes attached to the peroneal muscles to restrict ankle motion. When the stimulator receives the high-risk signal, its activated and the spraining motion would be alleviated. In this way, the ankle brace doesnt restrict normal ankle movement while providing adequate protection for potential ankle sprain cases.

ACCURACY OF MEASURING IN VIVO SYNDESMOSIS JOINT KINEMATICS DURING LEVEL GAIT

AbstractObjectivesThe syndesmosis joint, located between the tibia and fibula, is critical to maintaining the stability and function of the ankle joint. Damage to the ligaments that support this joint can lead to ankle instability, chronic pain, and a range of other debilitating conditions. Understanding the kinematics of a healthy joint is critical to better quantify the effects of instability and pathology. However, measuring this movement is challenging due to the anatomical structure of the syndesmosis joint. Biplane Video Xray (BVX) combined with Magnetic Resonance Imaging (MRI) allows direct measurement of the bones but the accuracy of this technique is unknown. The primary objective is to quantify this accuracy for measuring tibia and fibula bone poses by comparing with a gold standard implanted bead method.MethodsWritten informed consent was given by one participant who had five tantalum beads implanted into their distal tibia and three into their distal fibula from a previous study. Three-dimensional (3D) models of the tibia and fibula were segmented (Simpleware Scan IP, Synopsis) from an MRI scan (Magnetom 3T Prisma, Siemens). The beads were segmented from a previous CT and co-registered with the MRI bone models to calculate their positions. BVX (125 FPS, 1.25ms pulse width) was recorded whilst the participant performed level gait across a raised platform. The beads were tracked, and the bone position of the tibia and fibula were calculated at each frame (DSX Suite, C-Motion Inc.). The beads were digitally removed from the X-rays (MATLAB, MathWorks) allowing for blinded image-registration of the MRI models to the radiographs. The mean difference and standard deviation (STD) between bead-generated and image-registered bone poses were calculated for all degrees of freedom (DOF) for both bones.ResultsThe absolute mean tibia and fibula bone position differences (Table 1) between the bead and BVX poses were found to be less than 0.5 mm for both bones. The bone rotation differences were found to be less than 1° for all axes except for the fibula Z axis rotation which was found to be 1.46°. One study1 has reported the kinematics of the syndesmosis joint and reported maximum ranges of motion of 9.3°and translations of 3.3mm for the fibula. The results show that the accuracy of the methodology is sufficient to quantify these small movements.ConclusionsBVX combined with MRI can be used to accurately measure the syndesmosis joint. Future work will look at quantifying the accuracy of the talus to provide further understanding of normal ankle kinematics and to quantify the kinematics across a healthy population to act as a comparator for future patient studies.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

The interaction effect of different footwear types and static navicular drop or dynamic ankle pronation on the joint stiffness of the lower limb during running

BackgroundAlthough the effects of footwear type on joint stiffness have previously been investigated, researchers did not consider foot flexibility. Thus, the present investigation aimed to determine the interaction effects of footwear type, static navicular drop and dynamic ankle pronation on dynamic joint stiffness in running. Research questionDoes the footwear types in interaction with the foot posture affect the stiffness of the joints of the lower limb? MethodsForty-seven male individuals participated in this study. Firstly, they were divided into the high navicular, low navicular, and normal navicular drop. Secondly, they were divided into the high dynamic ankle pronation, low dynamic ankle pronation, and normal dynamic ankle pronation groups. Participants performed three running trials at 3 ± 0.2 m/s at minimalist footwear, conventional footwear, and barefoot conditions. We collected the ground reaction forces and three-dimensional kinematic data and calculated joint stiffness over the stance phase. ResultsThere was no significant main effect of navicular drop or dynamic ankle pronation on dynamic joint stiffness for the ankle, knee, and hip (p > 0.05). However, footwear type significantly affected dynamic joint stiffness. The pairwise comparison revealed that the ankle and hip dynamic joint stiffness magnitudes in the conventional footwear condition were greater than in the barefoot and minimalist footwear conditions (p 0.001). In contrast, the knee dynamic joint stiffness magnitude in the conventional footwear condition was lesser than in barefoot and minimalist footwear conditions (p 0.001). SignificanceThe navicular drop or dynamic ankle pronation did not influence lower limb joint stiffness, and there was no significant interaction between navicular drop or dynamic ankle pronation and footwear on lower limb dynamic joint stiffness. However, conventional footwear increased the ankle and hip dynamic joint stiffness while reducing knee dynamic joint stiffness, leading to changes in transfer energy, which could have implications for relative injury risk.

Differences in Cortical Activation During Dorsiflexion and Plantarflexion in Chronic Ankle Instability: A Task-fMRI Study.

Chronic ankle instability is a common sports injury that often presents with increased plantarflexion and restricted dorsiflexion. The cumulative effect of peripheral injuries may induce neuroplasticity in the central nervous system. However, the relationship between dorsiflexion or plantarflexion and the central nervous system in patients with chronic ankle instability remains unknown. (1) Is there a difference in region and voxel (volume pixel) of cortical activation during plantarflexion and dorsiflexion between patients with chronic ankle instability and a control group with normal ankle function? (2) Is there a correlation between activation of sensorimotor-related brain regions and three clinical measurement scales of ankle function and disease severity in patients with chronic ankle instability? Between December 2020 and May 2022, we treated 400 patients who had chronic ankle instability. Ten percent (40 patients; mean ± standard deviation age 29 ± 7 years; 17 male patients) were randomly selected to participate in this study. We recruited 42 volunteers with normal ankle function (mean age 28 ± 5 years; 21 male participants) matched by age and education level. A total of 2.5% (1 of 40) of patients with bilateral chronic ankle instability and 30% (12 of 40) with left-sided chronic ankle injury did not meet our inclusion criteria and were excluded from the study. The control group underwent MRI with good image quality. Finally, 27 patients with chronic ankle instability (mean age 26 ± 5 years; 10 male patients) and 42 participants with normal ankle function were enrolled. Ankle function and disease severity were assessed using three clinical scales: the Cumberland Ankle Instability Tool, Karlsson-Peterson Ankle Function Score, and the American Orthopedic Foot and Ankle Society Score. A uniplanar and nonweightbearing ankle dorsiflexion-plantarflexion paradigm (a recognized model or pattern) was performed using a short-block design during the functional MRI scan. This experimental design included a series of on-off periods consisting of movement and a rest period. From 15° of plantarflexion to 15° of dorsiflexion, the manipulator allowed 30° of ankle rotation. The cerebral excitability patterns between patients with chronic ankle instability and controls were analyzed using t-tests. We retained voxels with p values less than 0.05 in a voxel-level family-wise error correction. Clusters with voxel numbers greater than 10 were retained. The Cohen d coefficient was used to calculate between-group effect sizes. Spearman analysis was performed to explore the correlation between activation regions and the three clinical assessment scales. In the patient group, cortical activation was greater during plantarflexion than during dorsiflexion, which was different from that in the control group. The between-group comparison showed that patients with chronic ankle instability had reduced activation in the ipsilateral precuneus (cluster size = 35 voxels [95% CI -0.23 to 0.07]; p < 0.001) during dorsiflexion, whereas during plantarflexion, chronic ankle instability caused increased activation in the ipsilateral superior temporal gyrus (cluster size = 90 voxels [95% CI -0.73 to -0.13]; p < 0.001), precuneus (cluster size = 18 voxels [95% CI -0.56 to -0.19]; p < 0.001), supplementary motor area (cluster size = 57 voxels [95% CI -0.31 to 0.00]; p < 0.001), superior frontal gyrus (cluster size = 43 voxels [95% CI -0.82 to -0.29]; p < 0.001), medial part of the superior frontal gyrus (cluster size = 39 voxels [95% CI 0.41 to 0.78]; p < 0.001), and contralateral postcentral gyrus (cluster size = 100 voxels [95% CI -0.32 to 0.02]; p < 0.001). Patients with chronic ankle instability showed a large effect size compared with controls (Cohen d > 0.8). During plantarflexion, the number of activated voxels in the supplementary motor area had a modest, positive correlation with the Karlsson-Peterson Ankle Function Score (r = 0.52; p = 0.01), and the number of activated voxels in the primary motor cortex (M1) and primary sensory cortex (S1) had a weak, positive correlation with the American Orthopedic Foot and Ankle Society Score in patients with chronic ankle instability (M1: r = 0.45; p = 0.02, S1: r = 0.49; p = 0.01). Compared with volunteers with normal ankle function, patients with chronic ankle instability had increased cortical activation during plantarflexion and decreased cortical activation during dorsiflexion. We analyzed the central neural mechanisms of chronic ankle instability in patients with sports injuries and provided a theoretical basis for the development of new central and peripheral interventions in the future. Because there was a positive correlation between the neural activity in sensorimotor-related regions during plantarflexion and clinical severity, clinicians might one day be able to help patients who have chronic ankle instability with neuromuscular rehabilitation by applying electrical stimulation to specific targets (such as S1M1 and the supplementary motor area) or by increasing activation of sensorimotor neurons through ankle movement.

Numerical simulations of the effect of lateral malleolus fracture malunion on ankle biomechanics: Different offset directions and offsets

IntroductionAnkle fractures account for approximately 10 % of all fractures. Approximately 5–68 % of patients with ankle fractures may suffer from malunion. Besides, suboptimal reduction of fracture fragments can affect the biomechanics of the ankle joint, ultimately leading to damage to the ankle joint. However, there are certain controversies over the conclusion of previous cadaveric studies. MethodsIn this study, a three-dimensional model of the ankle joint was established based on CT image data. In addition, the effects of backward offset (1–2 mm) and outward offset (0.5–1 mm) of the fracture fragment on the contact area, contact pressure, and ligament force of the ankle joint were investigated via the finite element method. Moreover, lateral malleolus fracture malunion in five ankle positions (neutral, 10° dorsiflexion, 10° plantarflexion, 20° dorsiflexion, and 20° plantarflexion) was investigated. ResultsThis model predicted an overall increased contact area in the ankle joint in patients with lateral malleolus fracture malunion compared with the normal ankle joint. The results demonstrated that the outward offset had a more significant effect than the backward one. The larger the dorsiflexion-plantarflexion angle, the more pronounced the effect of malunion. Further, an outward offset can cause the fibula to lose its function. ConclusionPost-traumatic osteoarthritis occurs under the action of unaccustomed cartilage forces due to altered tibial talar joint contact patterns, rather than increased contact pressure reported in previous studies. Malunion leads to an increase or decrease in force on the affected ligament, while the cause of malunion can be envisioned based on a decrease in the force on the ligaments.

Evaluation of Leg-foot Range of Motion: Which Measurement Method is Most Reliable?

Category: Ankle Introduction/Purpose: The measurement of the ankle's range of motion is now considered of great importance for the diagnosis, therapeutic choice, and follow-up of the evolution of the treatment in patients with pathologies, both of the ankle and the whole hindfoot. However, there is no established method of choice for the safety assessment of talocrural mobility. Therefore, to evaluate the methods of measuring leg-foot movement in normal ankles and feet by comparing the results of clinical measurements with those of radiographic measurement and to determine the range of leg-foot movement considered normal. Methods: The leg-foot movement was measured in 44 patients (60 feet) using a traditional goniometer, digital goniometer, inclinometer, smartphone application, and radiographic measurement (considered gold standard). Maximum dorsiflexion was achieved by asking the patient to take a step forward with the contralateral foot and perform as much dorsiflexion as possible in the ankle studied without removing the heel from the ground. For maximum plantar flexion, the patient was asked to take a step back with the contralateral foot and make as much plantar flexion as possible without removing the studied forefoot from the ground. Results: The values obtained in radiographic measurement were higher than those obtained with clinical measurement. When we compared only the results of clinical measurement, the traditional goniometer was inaccurate. According to the radiographic method, the mean leg-foot range of motion was 65.6 degrees. The mean maximum plantar flexion was 34.9 degrees, and the mean maximum dorsiflexion was 30.7 degrees. Conclusion: The most appropriate method for evaluating the leg-foot range of motion is the radiographic one. The traditional goniometer proved to be the most imprecise clinical method. The mean leg-foot range of motion in healthy young adults was 65 degrees.

Lateral Talar Subluxation Measurements in Non-Operatively Managed Weber B Ankle Fractures

Category: Ankle; Trauma Introduction/Purpose: Isolated Weber B ankle fractures are common orthopedic injuries; however, indications for surgical management can be controversial. Stress radiographs have been utilized to evaluate the competence of the deltoid ligament, and recently lateral talar subluxation (LTS) has been described as a measurement tool for evaluating these injuries. It has been suggested that LTS &gt;4mm on gravity stress radiographs may be utilized to determine need for surgical intervention. In this study we review the LTS measurements in a cohort of non-operatively treated isolated Weber B fibula fractures to determine its utility as a tool to potentially guide treatment decisions and its association with patient outcomes. Methods: Our group previously presented a novel algorithm for non-operative management of isolated Weber B ankle fractures and enrolled a cohort of patients. Outcome scores were reported including American Orthopaedic Foot &amp; Ankle Society (AOFAS) hindfoot, Olerud-Molander (OMA), Foot and Ankle Ability Measure for Activities of Daily Living (FAAM/ADL), and Visual Analog Scale (VAS) scores. All patients achieved union of their fracture. For each patient we measured LTS on the injury gravity stress view x-rays as well as the un-injured contralateral side which has not been previously reported. A Kruskal-Wallis non-parametric test was used to determine whether there was any association of outcomes with extent of LTS. Results: 42 patients were included, with minimum 1 year follow-up. The average age was 49 years (range 19 to 72). On injury gravity stress radiographs, mean medial clear space (MCS) was 4.45 mm (SD = 0.93), superior clear space (SCS) 3.46 mm (SD = 0.70), and LTS 2.33 mm (SD = 1.57, range 0 – 4.7 mm), with 35 (83.3%) patients having LTS ≤ 4 mm. Contralateral (un-injured) gravity stress mean MCS was 3.39 mm (SD = 0.63), SCS 3.15 mm (SD = 0.50), and LTS 1.30 mm (SD = 1.28, range 0 - 4.8). There was no significant difference in outcome measures based on amount of LTS ( &lt; 2 mm, 2 to 4 mm, &gt;4 mm): AOFAS (p=0.41), OMA (p=0.40), FAAM/ADL (p=0.41), pain VAS (p=0.16). Conclusion: All patients in our cohort were successfully treated non-operatively. Most patients had injury LTS ≤ 4 mm, although those with LTS &gt;4 mm had excellent outcome scores as well. Amount of LTS did not correlate with outcomes. We present a large range of LTS measurements in normal ankles, which may be attributed to the high variability of these measurements and sensitivity to ankle rotation on radiographs. LTS may be a useful adjunct in evaluating isolated Weber B ankle fractures but may not be entirely reliable on its own. Further studies are required to validate LTS as a quantitative decision-making tool.