Clinical Features Post Anterior Cruciate Ligament Reconstruction Associated with Structural Alterations in Corticospinal Tract.

CONTEXT: Structural evidence for corticospinal tract (CST) abnormality between patients with ACLR and healthy controls, and the relationships between CST structure and clinical features of the patients (e.g., objective sensorimotor outcomes, postoperative duration) are lacking. OBJECTIVES: To investigate whether the structural features of CST 1) differ between patients with ACLR and healthy controls, and 2) were associated with clinical features in patients following ACLR. DESIGN: Cross-sectional study. SETTING: Sports medicine laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-six patients who had undergone ACLR and twenty-six healthy controls were enrolled in this cross-sectional investigation. MAIN OUTCOME MEASURE(S): Using the CST as the region of interest, we performed diffusion tensor imaging to measure the microstructure of white matter tracts. Between-group comparisons and correlation analyses with clinical features in patients with ACLR were performed. RESULTS: The patients with ACLR showed significant, moderate lower fractional anisotropy (FA, Cohen's d = -0.666, 95% CIs -1.221 to -0.104), lower axial diffusivity (AD, Cohen's d = -0.526, 95% CIs -1.077 to 0.030), and higher radial diffusivity (RD, Cohen's d = 0.514, 95% CIs -0.042 to 1.064) when compared to that of healthy controls, with the RD values being significantly correlated with the postoperative duration (r = 0.623, p < 0.001) after controlling the age, sex, and BMI in patients with ACLR. CONCLUSIONS: This study revealed that patients with ACLR have impaired integrity (lower FA values and higher RD values) in the CST contralateral to the ACLR injured limb in comparison with healthy controls. Decreased integrity (higher RD) of the CST in patients was significantly associated with longer postoperative duration, which hinted that impaired structural integrity of the CST may be a maladaptive process of neuroplasticity in ACLR.

Rehabilitation increases cortical activation during single-leg stance in patients with chronic ankle instability.

Background: Chronic ankle instability (CAI) has been considered a neurophysiological disease, having as symptoms dysfunction in somatosensory and motor system excitability. Rehabilitation has been considered an effective treatment for CAI. However, few studies have explored the effects of rehabilitation on neuroplasticity in the CAI population. Objective: The purpose of this study was to investigate the effects of rehabilitation on cortical activities for postural control in CAI patients and to find the correlation between the change in cortical activities and patient-reported outcomes (PROs). Methods: Thirteen participants with CAI (6 female, 7 male, age = 33.8 ± 7.7 years, BMI = 24.7 ± 4.9 kg/m2) received a home exercise program for about 40 min per day, four days per week and six weeks, including ankle range-of-motion exercise, muscle strengthening, and balance activities. Cortical activation, PROs and Y-balance test outcomes were assessed and compared before and after rehabilitation. Cortical activation was detected via Functional near-infrared spectroscopy (fNIRS) while the participants performed single-leg stance tasks. Results: The participants had better PROs and Y balance test outcomes after rehabilitation. Greater cortical activation was observed in the primary somatosensory cortex (S1, d = 0.66, p = 0.035), the superior temporal gyrus (STG, d = 1.06, p = 0.002) and the middle temporal gyrus (MTG, d = 0.66, p = 0.035) in CAI patients after rehabilitation. Moreover, significant positive correlations were observed between the recovery of ankle symptoms and the change of cortical activation in S1 (r = 0.74, p = 0.005) and STG (r = 0.72, p = 0.007) respectively. Conclusion: The current study reveals that six weeks of rehabilitation can cause greater cortical activation in S1, STG and MTG. This increase in cortical activation suggested a better ability to perceive somatosensory stimuli and may have a compensatory role in function improvement.

Insufficient recovery of proprioception in chronic ankle instability after surgical restabilization: A systematic review.

Surgical repair or reconstruction of the lateral ligaments for patients with chronic ankle instability (CAI) could, logically, restore the proprioception of ankle through retensing receptors. To validate this hypothesis, seven databases were systematically searched, and thirteen studies comprising a total of 347 patients with CAI were included. Although five studies reported improved proprioceptive outcomes after surgeries, the other five studies with between-limb/group comparisons reported residual deficits at final follow-up, which does not consistently support proprioceptive recovery after existing surgical restabilization for CAI. More controlled studies are needed to provide evidence-based protocols to improve proprioceptive recovery after ankle restabilization for CAI.

Postural Control Deficits During Static Single-leg Stance in Chronic Ankle Instability: A Systematic Review and Meta-Analysis.

CONTEXT: Postural control deficits arising from injured ankles are central to chronic ankle instability (CAI) and its persistent symptoms. This is usually measured by recording the center of pressure (CoP) trajectory during static single-leg stance using a stable force plate. However, existing studies have produced conflicting results on whether this mode of measurement adequately reveals the postural deficits in CAI. OBJECTIVE: To determine whether postural control during static single-leg stance is impaired in CAI patients when compared with uninjured healthy controls. DATA SOURCES: Literature databases, PubMed, Embase, Web of Science, Cochrane Library, Scopus, CINAHL, and SPORTDiscus, were searched from inception to April 1, 2022, using ankle-, injury-, and posture-related terms. STUDY SELECTION: Two authors independently performed the step-by-step screening of article titles, abstracts, and full texts to select peer-reviewed studies investigating CoP trajectory during static single-leg stance using a stable force plate in CAI patients and healthy controls. A total of 13,637 studies were reviewed, and 38 studies (0.003%) met the selection criteria. STUDY DESIGN: Meta-analyses of descriptive epidemiological study. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: CoP parameters, sway directions, visual condition, and numerical data (means and standard deviations) were extracted. RESULTS: The injured ankles of CAI patients had higher standard deviations of sway amplitude in both anterior-posterior and medial-lateral directions (standardized mean difference [SMD] = 0.36 and 0.31, respectively) under conditions of open eyes than controls. Higher mean sway velocity in anterior-posterior, medial-lateral, and total directions (SMD = 0.41, 0.37, and 0.45, respectively) with closed eyes was also found. CONCLUSION: CAI patients had deficits of postural control during static single-leg stance, and these deficits were identified by the CoP trajectory. Further methodological explorations of CoP parameters and corresponding test conditions are required to enhance the sensitivity and reliability of postural deficit assessments in CAI using force plates.

In Vivo Characterization of Cerebellar Peduncles in Chronic Ankle Instability: A Single and Multishell Diffusion-Weighted Imaging Study.

BACKGROUND: Ankle sprain causes proprioceptor injuries and prolonged joint deafferentation, which might lead to maladaptive neuroplasticity in patients with chronic ankle instability (CAI), especially in the cerebellum. Previous studies have indicated the impairment of superior cerebellar peduncle (SCP), but the inferior cerebellar peduncle (ICP) and middle cerebellar peduncle (MCP) have not been fully analyzed. HYPOTHESIS: The cerebellar peduncles of participants with CAI would have altered fractional anisotropy (FA) and orientation dispersion index (ODI) in comparison with healthy controls without ankle injury history. In addition, FA and ODI would be correlated with the duration or severity of the sensorimotor deficits in CAI. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: A group of 27 participants with CAI and 26 healthy controls underwent diffusion-weighted imaging scanning, with the cerebellar peduncles as the regions of interest. The measures obtained by single-shell diffusion tensor imaging and the multishell neurite orientation dispersion and density imaging were used. Correlation analyses were performed to examine the potential relationship between the FA/ODI and both the normalized Y-balance scores and the durations of ankle instability. RESULTS: The ipsilateral ICP of the injured ankle in participants with CAI showed significantly lower FA (Cohen d 95% CI, -1.33 to -0.21; P = 0.04) and marginally significant higher ODI (Cohen d 95% CI, 0.10 to 1.20, P = 0.08) when compared with the same measures in the control group, with the ODI being positively correlated with the duration of ankle instability (r = 0.42, P = 0.03). CONCLUSION: The ICP in participants with CAI exhibited impaired integrity and a trend of abnormally organized neurites in comparison with a healthy control group. CLINICAL RELEVANCE: The impairments of ICP might be an ongoing part of the pathological process of CAI, having the potential to become a target for the diagnostic evaluation of this clinical entity.

Thin and Plain Supplementary Motor Area in Chronic Ankle Instability: A Volume and Surface-based Morphometric Study.

CONTEXT: The supplementary motor area (SMA) is involved in the functional deficits of chronic ankle instability (CAI), but the structural basis of its abnormalities remains unclear. OBJECTIVE: To determine the differences in volume and surface-based morphological features of SMA between patients with CAI and healthy controls, and their relationship with the clinical features of CAI. DESIGN: Cross-sectional study. SETTING: Sports medicine laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 32 CAI patients (10 females; age: 32.46 ± 7.51 years) and 31 healthy controls (12 females; age: 29.70 ± 8.07 years) participated in this study. MAIN OUTCOME MEASURE(S): Participants perform T1 structural magnetic resonance imaging and calculate volume and surface-based morphological features of SMA subregions. These included anterior and posterior subdivisions of Brodmann's area 6 m (6 ma/6 mp), and supplementary and cingulate eye fields. Between-group comparisons and correlation analysis with clinical features of CAI were performed. RESULTS: Moderately thinner 6 mp (Cohen's d = -0.61) and moderately plainer 6 ma (Cohen's d = -0.70) were observed in patients compared with controls. Before and after regressing out the covariates, the thinner 6 mp was correlated with the lower foot and ankle ability measure scores of daily activities (r-before=0.400, r-after = 0.449). CONCLUSIONS: Patients with CAI had a thinner posterior subdivision (motor-output site) and a plainer anterior subdivision (motor-planning site) of SMA than that of controls. The thin motor-output site of the SMA is associated with ankle dysfunction in patients. These morphologic evidence of maladaptive neuroplasticity in SMA might promote more targeted rehabilitation of CAI.

Therapeutic effects following extracorporeal shock wave therapy for insertional and non-insertional Achilles tendinopathy.

Background: The treatment for Achilles tendinopathy varies widely, and there is no consensus regarding the optimal treatment for both non-insertional and insertional Achilles tendinopathy. The purpose of this study was to evaluate the clinical efficacy of extracorporeal shock wave therapy (ESWT) in the treatment of insertional and non-insertional Achilles tendinopathy (AT). Methods: Sixty patients with AT were invited to participate in this study. Patients were allocated to one of two groups according to the site of the AT, including an insertional AT (IAT) group and a non-insertional AT (NIAT) group. ESWT was performed once a week for five weeks for both groups. The Victorian Institute of Sport Assessment-Achilles questionnaire (VISA-A) score and the visual analog scale (VAS) were used five times to evaluate the clinical outcomes, including before treatment, immediately after treatment, as well as one month, three months, and five years after treatment. Results: At three months after treatment, the IAT group exhibited a significantly higher VISA-A score (82 ± 6 vs. 76 ± 11; p = 0.01) and a significantly lower VAS score (1 ± 1 vs. 2 ± 1; p < 0.001) when compared with the NIAT group. At the five-year assessment, the IAT group (1 ± 1) had a significantly lower VAS score than the NIAT group (2 ± 1) (p = 0.02), while no significant difference for the VISA-A score was observed between the groups (84 ± 8 vs. 84 ± 10; p = 0.98). Conclusions: Extracorporeal shock wave treatment can improve the symptoms of both insertional and non-insertional AT. The IAT patients experienced better clinical outcomes compared with the NIAT patients.

Identification of four-gene signature to diagnose osteoarthritis through bioinformatics and machine learning methods.

BACKGROUND: Although osteoarthritis (OA) is one of the most prevalent joint disorders, effective biomarkers to diagnose OA are still unavailable. This study aimed to acquire some key synovial biomarkers (hub genes) and analyze their correlation with immune infiltration in OA. METHODS: Gene expression profiles and clinical characteristics of OA and healthy synovial samples were retrieved from the Gene Expression Omnibus (GEO) database. Hub genes for OA were mined based on a combination of weighted gene co-expression network analysis (WGCNA), the least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF) algorithms. A diagnostic nomogram model for OA prediction was developed based on the hub genes. Receiver operating characteristic curves (ROC) were performed to confirm the abnormal expression of hub genes in the experimemtal and validation datasets. qRT-PCR using patients' samples were conducted as well. In addition, the infiltration level of 28 immune cells in the expression profile and their relationship with hub genes were analyzed using single-sample GSEA (ssGSEA). RESULTS: 4 hub genes (ZBTB16, TNFSF11, SCRG1 and KDELR3) were obtained by WGCNA, lasso, SVM-RFE, RF algorithms as potential biomarkers for OA. The immune infiltration analyses revealed that hub genes were most correlated with regulatory T cell and natural killer cell. CONCLUSION: A machine learning model to diagnose OA based on ZBTB16, TNFSF11, SCRG1 and KDELR3 using synovial tissue was constructed, providing theoretical foundation and guideline for diagnostic and treatment targets in OA.

Neuroplasticity of pain processing and motor control in CAI patients: A UK Biobank study with clinical validation.

Background: Pain plays an important role in chronic ankle instability (CAI), and prolonged pain may be associated with ankle dysfunction and abnormal neuroplasticity. Purpose: To investigate the differences in resting-state functional connectivity among the pain-related brain regions and the ankle motor-related brain regions between healthy controls and patients with CAI, and explore the relationship between patients' motor function and pain. Study design: A cross-database, cross-sectional study. Methods: This study included a UK Biobank dataset of 28 patients with ankle pain and 109 healthy controls and a validation dataset of 15 patients with CAI and 15 healthy controls. All participants underwent resting-state functional magnetic resonance imaging scanning, and the functional connectivity (FC) among the pain-related brain regions and the ankle motor-related brain regions were calculated and compared between groups. The correlations between the potentially different functional connectivity and the clinical questionnaires were also explored in patients with CAI. Results: The functional connection between the cingulate motor area and insula significantly differed between groups in both the UK Biobank (p = 0.005) and clinical validation dataset (p = 0.049), which was also significantly correlated with Tegner scores (r = 0.532, p = 0.041) in patients with CAI. Conclusion: A reduced functional connection between the cingulate motor area and the insula was present in patients with CAI, which was also directly correlated with reduction in the level of patient physical activity.

Do exercise therapies restore the deficits of joint position sense in patients with chronic ankle instability? A systematic review and meta-analysis.

To determine whether existing exercise therapies can restore the joint position sense (JPS) deficits of patients with chronic ankle instability (CAI) when compared with controlled non-training patients. Seven databases were searched using ankle, injury, proprioception, and exercise-therapy-related terms. Peer-reviewed human studies in English that used the absolute errors score of joint position reproduction (JPR) test to compare the JPS of injured ankles in CAI patients before and after exercise therapy and non-training controls were included and analyzed. Demographic information, sample size, description of exercise therapies, methodological details of the JPR test, and absolute error scores were extracted by two researchers independently. Meta-analysis of the differences in JPS changes (i.e., absolute errors after treatment minus the baseline) between the exercise therapies and non-training controls was performed with the weighted mean difference (WMD) and 95% confidence interval (CI). Seven studies were finally included. Meta-analyses revealed significantly higher improvements in passive JPS during inversion with, WMD â€‹= â€‹-1.54° and eversion, of, WMD â€‹= â€‹-1.80°, after exercise therapies when compared with non-training controls. However, no significant changes in the impaired side active JPS were observed with regard to inversion and eversion. Existing exercise therapies may have a positive effect on passive JPS during inversion and eversion, but do not restore the active JPS deficits of injured ankles in patients with CAI when compared with non-training controls. Updated exercise components with a longer duration that focus on active JPS with longer duration are needed to supplement the existing content of exercise therapies.

Outcomes of a novel all-inside arthroscopic anterior talofibular ligament repair for chronic ankle instability.

PURPOSE: This study aimed to introduce a novel all-inside arthroscopic anterior talofibular ligament (ATFL) repair for chronic ankle instability (CAI) with a knotless suture anchor technique-Hugging Repair, evaluate clinical outcomes, and analyze the associated risk factors. METHODS: A total of 84 patients (42 males and 42 females, mean age: 36.1 ± 11.2 years, range: 19-68 years) who underwent Hugging Repair from January 1, 2016 to December 31, 2018, were enrolled in this retrospective study. The American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson Ankle Functional Score (KAFS), Foot and Ankle Outcome Score (FAOS), Tegner score, and Numerical Rating Scale (NRS) were evaluated pre-operatively and at final follow-up. The potential risk factors such as age, body mass index (BMI), sex, post-injury duration (time from injury to surgery), follow-up time, number of anchors, concomitant injuries [e.g., osteochondral defects (OCD), sinus tarsi syndrome (STS), anterior ankle impingement (AAI)], first-time treatment, and number of ankle sprains were also analyzed through multiple regression analysis. RESULTS: There were 68 (81%) patients followed up for a mean time of 42 (range: 35-50) months. The median AOFAS score increased from 65 (35-72) to 90 (77-100), KAFS increased from 64 (38-71) to 90 (62-100), FAOS increased from 68 (50-70) to 97 (68-100), Tegner score increased from 1 (1-3) to 4 (2-7), and NRS increased from 3.5 (2-5) to 1 (0-3). No correlation was found between the functional scores and risk factors mentioned above. In the multivariate model, age was significantly negatively associated with KAFS, FAOS, and Tegner activity scale (P = 0.013; P = 0.002; P = 0.000); female was significantly associated with poorer Tegner activity scale (P = 0.004); and the presence of concomitant injuries was significantly negatively associated with AOFAS score (P = 0.033). CONCLUSION: The novel all-inside arthroscopic ATFL repair for CAI with a knotless suture anchor technique-Hugging Repair is a safe and suitable technique that achieves satisfactory clinical outcomes and provides an effective option for the treatment of CAI. Risk factors for patients who underwent all-inside ATFL repair were older age, female sex, and concomitant injuries.

Maladaptive Neuroplasticity in Corticospinal Tract after Ankle Sprain: Causal Links Established by Mendelian Randomization.

PURPOSE: It has been hypothesized that the corticospinal tract (CST) is involved in the neural origins underlying muscular deficits after an ankle sprain. Microstructural differences in the CST have been reported in patients with and without a history of ankle sprain, but the causal links between the CST and the injuries have not been verified. This study aimed to explore whether genetically predisposed ankle sprains would impair the integrity and organization of CST neurites, manifesting as reduced fractional anisotropy (FA) and increased orientation dispersion index (ODI). METHODS: Single-nucleotide polymorphisms (SNP) associated with ankle sprains were identified from genome-wide association studies (GWAS) in FinnGen based on hospital discharge records (7223 cases and 245,598 controls). Outcome statistics for CST microstructures were collected from the GWAS from diffusion-weighted-imaging outcomes in the UK Biobank (33,224 participants). Random-effect, inverse-variance weighted Mendelian randomization was used as the primary method. RESULTS: Eighteen SNP were selected as forming possible causal links between ankle sprains and CST structure; F value ranged from 755 to 1026. Ankle sprains were associated with a reduction in the FA of the right CST ( ß = -0.033, P = 0.0439), whereas no significant effects were observed on the left side ( ß = -0.029, 0.004; P = 0.0748). Ankle sprains significantly increased the ODI of the left CST ( ß = 0.053, P = 0.0036) and the right CST ( ß = 0.038, P = 0.0259). No significant pleiotropy or heterogeneity was observed in the analyses. CONCLUSIONS: A genetic predisposition to ankle sprains can lead to maladaptive neuroplasticity of the CST, manifesting as abnormally organized neurites.

Cortical Activation During Single-Legged Stance in Patients With Chronic Ankle Instability.

CONTEXT: Chronic ankle instability (CAI) has been considered a neurophysiological condition, with dysfunctional somatosensory and motor system excitability. However, few researchers have explored the changes in cortical activation during balance tasks of patients with CAI. OBJECTIVE: To compare the cortical activity during single-legged stance among CAI, copers, and uninjured control participants and to compare dynamic balance across groups. DESIGN: Cross-sectional study. SETTING: Biomechanics laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 22 participants with CAI (median [interquartile range]; age = 34.5 [11.0] years, height = 170.0 [15.8] cm, mass = 67.0 [16.2] kg), 17 copers (age = 27.0 [14.0] years, height = 170.0 [9.5] cm, mass = 66.5 [16.5] kg), and 21 uninjured control participants (age = 25.0 [10.5] years, height = 170.0 [11.0] cm, mass = 64.0 [16.5] kg). MAIN OUTCOME MEASURE(S): Participants performed single-legged stance while cortical activation was tested with functional near-infrared spectroscopy. The peak oxyhemoglobin response of the activated cortex was calculated and compared across groups. The Y-Balance test outcomes and patient-reported outcomes were assessed and compared across groups. RESULTS: The CAI group had worse Y-balance test and patient-reported outcomes than the coper and uninjured control groups. Differences in the peak oxyhemoglobin response were observed for the primary somatosensory cortex (S1; F2,57 = 4.347, P = .017, ηp2 = 0.132) and superior temporal gyrus (STG; F2,57 = 4.548, P = .015, ηp2 = 0.138). Specifically, copers demonstrated greater activation in S1 and STG than the CAI (d = 0.73, P = .034, and d = 0.69, P = .043, respectively) and uninjured control (d = 0.77, P = .036, and d = 0.88, P = .022, respectively) groups. No differences were found in the cortical activation between CAI and uninjured control participants. CONCLUSIONS: Copers displayed greater cortical activation in S1 and STG than CAI and uninjured control participants. Greater activation in S1 and STG suggested a better ability to perceive somatosensory stimuli and may represent a compensatory mechanism that allows copers to maintain good functional ability after the initial severe ankle sprain.

Does radiofrequency application improve function and reduce pain in patients with insertional Achilles tendinopathy? A retrospective study with a minimum 2-year follow-up.

This case series study aimed to investigate patients with insertional Achilles tendinopathy (IAT) who underwent radiofrequency (RF), how much do their patient-reported outcomes scores improve and what percentage return to sport, and what patient-related factors are associated with improved scores and increased odds of return to sport, at a minimum of 2-year follow-up. Between 2012 and 2018, 41 patients were followed up. The median Victorian Institute of Sports Assessment-Achilles (VISA-A) score increased from 20 (range, 3-62) to 97 (range, 53-100), the median 11-point visual analogue scale (VAS) reduced from 8 (range, 1-10) to 0 (range, 0-3) and the median Tenger score increased from 1 (range, 0-1) to 3 (range, 2-8). Thirty-eight (92.7%) patients returned to sports with a mean time of 11 ± 4.8 months. In linear regression analysis, age was significantly associated with return-to-sports outcome (b = -0.07, 95% CI = -0.13 to -0.02, p = 0.02), while in logistic regression, symptoms duration revealed a significant impact on pain presence (OR = 1.07, 95% CI = 1.01 to 1.14, p = 0.02). In summary, RF for IAT had a 68.7 ± 14.5 VISA-A improvement at 5.4 years of follow-up regarding reliable functional restoration and pain reduction; however, the current evidence remains insufficient to support RF as an effective treatment for IAT.

Force sense deficits in chronic ankle instability: A systematic review and meta-analysis.

OBJECTIVE: Patients with chronic ankle instability (CAI) may experience ankle force sense deficits due to mechanoreceptor injury and proprioceptive deafferentation in the affected ankles. This study aimed to systematically review the literature and investigate (1) whether patients with CAI have impaired force sense when compared with uninjured contralateral sides or healthy controls, and (2) which characteristics of CAI (e.g., any measurement of CAI symptoms, clinical questionnaires, or functional tests on the injured ankles) are correlated with force sense deficits. TYPE: Systematic review and meta-analysis. LITERATURE SURVEY: PubMed, Embase, Web of Science, Cochrane Library, Scopus, CINAHL, and SPORTDiscus were searched for ankle-related, injury-related, and force sense-related terms from inception to February 2, 2022. METHODOLOGY: The following information was extracted from included articles: demographic data, sample size, selection criteria, methodology, force reproduction test outcomes, and correlations between force sense and other characteristics of CAI. Meta-analyses were conducted for the force sense outcomes, and a narrative review was undertaken for the correlation between force sense deficits and other characteristics of CAI. SYNTHESIS: Eight studies were included. The meta-analyses revealed eversion force sense deficits of the injured ankles in absolute error (magnitude of force reproduction error) at 20% maximal voluntary isometric contractions (MVIC) (standardized mean difference [SMD] = 0.67, 95% confidence interval [CI] 0.23-1.11) and variable error (consistency of force reproduction) at 30% MVIC (SMD = 0.46, 95% CI 0.07-0.85), as compared with healthy controls. None of the included studies reported a significant correlation between these two deficits and other characteristics of CAI. CONCLUSIONS: Patients with CAI have eversion force sense deficits in the magnitude of force reproduction error at 20% MVIC and the consistency of force reproduction at 30% MVIC.

Longitudinal neuroplasticity after ankle sprain in mice: A voxel-based morphometry study on 11.7T MRI.

Lateral ankle sprains (LAS) might lead to joint sensory deafferentation, which induces maladaptive neuroplasticity, especially the morphological atrophy of the cerebellar vermis. However, longitudinal evidence on the causality of injury and neural differences is still lacking. To this end, this study aimed to determine whether the morphology of the central nervous system would be altered before and after ligament transection in LAS mouse models. A total of 40 C57BL/6 mice were randomly divided among the LAS, Sham and Blank groups. We repeatedly performed the balance beam test and neural voxel-based morphometry (VBM) measurements using an 11.7 T magnetic resonance imaging before and 2 months after the surgery. The results showed that for balance outcomes, the LAS group had a significantly longer time and more slips of the balance beam tests compared with the Sham and Blank groups at 2 months after surgery, with no significant difference among the three groups before surgery. Regarding the VBM analysis, the LAS group showed significantly lower VBM values in the central lobule III of the cerebellar vermis and medial amygdalar nucleus (MEA) compared with the Sham and Blank groups after surgery, with no significant difference among the three groups before surgery. In conclusion, lateral ligament injuries might lead to morphological atrophy of the cerebellar vermis in animal models, which might pave the way for the pathological process of ankle instability after LAS.

Low Regional Homogeneity of Intrinsic Cerebellar Activity in Ankle Instability: An Externally Validated rs-fMRI Study.

PURPOSE: Joint deafferentation after post-ankle sprain ligament healing can disrupt sensory input from the ankle and induce maladaptive neuroplasticity, especially in the cerebellum. This study aimed to determine whether the regional homogeneity of intrinsic cerebellar activity differs between patients with ankle instability and healthy controls without a history of ankle injury. METHODS: The current study used a primary data set of 18 patients and 22 healthy controls and an external UK Biobank data set of 16 patients with ankle instability and 69 healthy controls for a cross-database, cross-sectional investigation. All participants underwent resting-state functional magnetic resonance imaging to calculate their regional homogeneity (ReHo) value. Between-group comparisons of the sensorimotor-related subregions of the cerebellum were first performed in the primary data set to identify low cerebellar ReHo in patients with multiple comparison corrections, and the surviving subregions were then externally validated in the UK Biobank data set. Correlation analyses between the ReHo values and clinical features were also performed. RESULTS: The ReHo value of cerebellar lobule VIIIb was significantly lower in the ankle instability group than in the controls (0.170 ± 0.016 vs 0.184 ± 0.019 in the primary data set, 0.157 ± 0.026 vs 0.180 ± 0.042 in the UK Biobank data set). The ReHo values of this subregion showed a significant positive correlation with the Cumberland Ankle Instability Tool scores in the ankle instability group (r = 0.553, P-corrected = 0.0348). CONCLUSIONS: Patients with ankle instability had lower intraregional coherence in cerebellar lobule VIIIb than that of controls, which was also positively correlated with the intensity of self-reported ankle instability.

Impaired corticospinal tract in chronic ankle instability: A diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) study at 7.0 Tesla.

OBJECTIVES: Electrophysiological studies have revealed that abnormal function of the corticospinal pathway might contribute to chronic ankle instability, but structural evidence underlying the abnormality is lacking. The purpose of this study was to quantitate microstructural differences between corticospinal tracts in patients with chronic ankle instability and healthy controls. DESIGN: Cross-sectional. METHODS: Seventeen patients with chronic ankle instability and sixteen healthy controls underwent diffusion weighted-imaging scans using an ultra-high-field 7.0 Tesla magnetic resonance imaging scanner. We focused on corticospinal tracts as a region of interest and performed classical diffusion tensor imaging and the advanced neurite orientation dispersion and density imaging outcomes that measured the microstructure of white matter tracts. Correlation analyses were also performed between the significantly different diffusion outcomes in both groups. RESULTS: The patients with chronic ankle instability showed significantly lower fractional anisotropy (p-corrected = 0.045) and higher orientation dispersion index (p-corrected = 0.033) when compared with healthy controls. These two measures were significantly correlated in the healthy controls (r = -0.56, p = 0.024) and the CAI patient group (r = -0.53, p = 0.029). CONCLUSIONS: This study revealed that the contralateral corticospinal tract of the unstable ankle in patients with chronic ankle instability exhibited impaired integrity, which was associated with abnormally organized neurites. We propose that this is a useful target for the clinical assessment of chronic ankle instability and the development of targeted neuromuscular rehabilitation.

Do External Supports Influence Proprioception in Patients With Chronic Ankle Instability?: A Systematic Review and Meta-analyses.

OBJECTIVE: Individuals with chronic ankle instability experience recurring sprains and impaired proprioception, and the effect of external support in the proprioception of injured ankles is still inconsistent in existing studies. Therefore, this study aimed to investigate whether external support could enhance the proprioception of injured ankles in patients with chronic ankle instability. DESIGN: This was a systematic review and meta-analysis. RESULTS: Eight studies from PubMed, Embase, Cochrane Library, Web of Science, SPORTDiscus, Scopus, and CINAHL were finally included after applying the exclusion criteria. Meta-analyses revealed a significantly higher joint position sense on inversion with a weighted mean difference of 1.25 degrees and plantar flexion (weighted mean difference, 1.74 degrees) and lower kinesthesia in eversion (weighted mean difference = -0.70 degrees) with the application of external support in the injured ankles of patients with chronic ankle instability. CONCLUSION: Applying external support has statistically significant negative effects on kinesthesia and a positive effect on the active joint position sense in the injured ankles of patients with chronic ankle instability. However, this study did not support the restoration of proprioception deficits as a mechanism of external support in preventing reinjuries, owing to its potentially negative effect on kinesthesia, clinically small changes in proprioception, and poor methodologic quality of existing studies.

Deactivation of the dorsal anterior cingulate cortex indicated low postoperative sports levels in presurgical patients with chronic ankle instability.

BACKGROUND: Injury-related fear contributed to disability in chronic ankle instability (CAI), while there still lacked exploration on the appraisal processes of the injury-related stimuli. This study aimed to compare the neural activities of the appraisal processes of sprain-related stimuli between presurgical chronic ankle instability patients and healthy controls through functional magnetic resonance imaging (fMRI) and evaluate its relationships with the clinical outcomes of orthopedic surgeries. METHODS: Eighteen presurgical CAI patients and fourteen healthy controls were recruited and underwent an fMRI session with visual stimulation of movies that showing typical ankle sprains accidents or control videos and the corresponding fear ratings. The clinical outcomes were collected at baseline and a minimum of 2 years after surgery; these included the American Orthopaedic Foot and Ankle Society (AOFAS) scores, the Numeric Rating Scale (NRS) scores, and the Tegner Activity Rating Scale scores. The two-sample t-test would be applied to identify which brain regions were influenced by CAI, and the correlation analysis would be applied to measure the relationship between the activation and clinical outcomes. RESULTS: Dorsal anterior cingulate cortex (dACC) was deactivated in CAI patients when compared with healthy controls, and the dACC deactivation strength revealed a moderate correlation with the values of fear ratings for all participants. The deactivation strength was negatively correlated with AOFAS at baseline, with Tegner at follow-up and its improvement. CONCLUSIONS: Presurgical CAI patients presented deactivated dACC as a different neural activity of appraisal processes of sprain-related stimuli when compared with healthy controls, which was associated with lower postoperative sports levels. More comprehensive patients care including psychological interventions were needed in the clinical management of chronic ankle instability.