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Whether the lateral ankle ligaments contribute to syndesmotic stability is still controversial and has been the subject of frequent research recently. In our study, we tried to elucidate this situation using the finite element analysis method. Intact model and thirteen different injury models were created to simulate injuries of the lateral ankle ligaments (ATFL, CFL, PTFL), injuries of the syndesmotic ligaments (AITFL, IOL, PITFL) and their combined injuries. The models were compared in terms of LFT, PFT and EFR. It was observed that 0.537 mm LFT, 0.626 mm PFT and 1.25° EFR occurred in the intact model (M#1), 0.539 mm LFT, 0.761 mm PFT and 2.31° EFR occurred in the isolated ATFL injury (M#2), 0.547 mm LFT, 0.791 mm PFT and 2.50° EFR occurred in the isolated AITFL injury (M#8). The LFT, PFT and EFR amounts were higher in the both M#2 and M#8 compared to the M#1. LFT, PFT and EFR amounts in M#2 and M#8 were found to be extremely close. In terms of LFT and PFT, when we compare models with (LFT: 0.650 mm, PFT: 1.104) and without (LFT: 0.457 mm, PFT: 1.150) IOL injury, it is seen that the amount of LFT increases and the amount of PFT decreases with IOL injury. We also observed that injuries to the CFL, PTFL and PITFL did not cause significant changes in fibular translations and PFT and EFR values show an almost linear correlation. Our results suggest that ATFL injury plays a crucial role in syndesmotic stability.

Background: Ankle osteoarthritis (OA) mainly arises from trauma, particularly lateral ligament injuries. Among lateral ligament injuries, ankles with calcaneofibular ligament (CFL) injuries exhibit increased instability and can be a risk factor ankle OA progression. However, the relationship between CFL injury and OA progression remains unclear. Therefore, this study aims to assess the relationship between CFL injuries and ankle OA by investigating stress changes and osteophyte formation in subtalar joint., Methods: We retrospectively reviewed the magnetic resonance imaging (MRI) and plain radiographic evaluations of 100 ankles of 91 patients presenting with chronic ankle instability (CAI), ankle OA, or other ankle conditions. The association between CFL injuries on the oblique view of MRI and the severity of ankle OA (based on Takakura-Tanaka classification) was statistically evaluated. Additionally, 71 ankles were further subjected to CT evaluation to determine the association between the CFL injuries and the Hounsfield unit (HU) ratios of the subtalar joint and medial gutter, and the correlation between the subtalar HU ratios and osteophyte severity were statistically evaluated., Results: CFL injury was observed in 35.9% (14/39) of patients with stage 0, 42.9% (9/21) with stage 1, 50.0% (10/20) with stage 2, 100% (9/9) with stage 3a, and 90.9% (10/11) with stage 3b. CFL-injured ankles exhibited higher HU ratios in the medial gutter and lower ratios in the medial posterior subtalar joint compared to uninjured ankles. A negative correlation was observed between medial osteophyte severity and the medial subtalar joint HU ratio., Conclusion: Our findings suggest that CFL injuries are common in severe ankle OA impairing the compensatory function of the subtalar joint through abnormal stress distribution and osteophyte formation., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Disclosure forms for all authors are available online.

Background: Ligamentous ankle injuries are the most common injuries sustained by athletes and by the general population, with an incidence of approximately 2 million per year in the U.S. Injuries to the ankle syndesmosis (i.e., "high ankle sprains") are generally treated operatively. Although cadaveric studies can evaluate syndesmosis fixation strength, they cannot predict how healing, neuromuscular adaptation, or dynamic loading will affect in vivo biomechanics. Using dynamic biplane radiography (DBR), we tested the hypothesis that syndesmosis repair would restore ankle kinematics and ligament elongation during static and dynamic loading., Methods: A convenience sample of 6 male patients who had undergone fixation (2 screw, 3 suspensory, 1 hybrid) of syndesmosis injury were assessed with use of DBR during forward running, backpedaling, a 45° angled single-leg hop, and 1 static standing trial at 2 to 4.5 years postoperatively. Three-dimensional ankle kinematics and elongation of the distal interosseous ligament, anterior inferior tibiofibular ligament, and the posterior inferior tibiofibular ligament were measured bilaterally. Comparisons were made between the operative and uninjured sides. Clinical outcomes were evaluated with use of the Foot and Ankle Ability Measure., Results: Static load increased the lengths of the distal interosseous ligament (p = 0.02 to 0.05) and middle segment of the anterior inferior tibiofibular ligament (p = 0.02) in the operative ankle. The distal syndesmosis length was greater on the operative side during the static unloaded and loaded conditions (p = 0.02). Length of the distal syndesmosis on the operative side was greater than the corresponding healthy syndesmosis length during all 3 dynamic activities. On average, the operative ankle was in less dorsiflexion over the support phase of the angled hop (p = 0.05) and running (p < 0.01). The average Foot and Ankle Ability Measure Activities of Daily Living and Sports subscale scores were 95 and 88, respectively., Conclusions: This study provides the first in vivo evidence of post-fixation changes in biomechanics after syndesmosis repair. Syndesmosis repair fails to restore healthy static and dynamic distal tibiofibular anatomy, even in patients who report good to excellent clinical outcomes., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJS/G521)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Purpose: To determine the effects of unilateral and bilateral ankle stabilization surgery with or without additional concurrent procedures for other pathologies on return to activity in patients who were allowed unrestricted weight bearing postoperatively., Methods: Ninety-three athletes underwent 120 ankle stabilization surgeries including 27 that underwent bilateral simultaneous surgery using the all-inside arthroscopy-modified lasso-loop technique and were divided into two groups: arthroscopic ligament repair alone without concurrent procedures (group A) and with simultaneous procedures for other pathologies (group B). Group A was further subdivided into unilateral (group A1) and simultaneous bilateral ankle surgery (group A2), and group B into ankle stabilization surgery with simultaneous procedures not requiring weight bearing postoperatively (Group B1) and with concurrent procedures allowing weight bearing (Group B2). Return to activity postoperatively was assessed by recording the time to walk without any support, jog, and return to full athletic activities. Clinical outcomes were assessed preoperatively and 12 months postoperatively using a subjective clinical score., Results: The average time between surgery and unsupported walk, jog, and return to full athletic activities was 1.6 ± 2.5, 16.9 ± 3.7, and 42.4 ± 19.3 days in group A, 17.2 ± 19.6, 34.5 ± 20.8, and 60.9 ± 22.8 days in group B, 1.7 ± 2.9, 16.1 ± 2.4, and 41.6 ± 18.2 days in group A1, 1.3 ± 0.6, 18.9 ± 5.5, and 44.6 ± 22.5 days in group A2, 25.3 ± 20.2, 43.3 ± 21.1, and 70.7 ± 23.1 days in group B1, and 4.8 ± 11.7, 20.7 ± 11.7, and 45.0 ± 13.7 days in group B2, respectively. These results indicate that the patients in group B2 showed a statistically significant faster time to return to activity than did those restricted from weight bearing. Differences in ankle stabilization alone between patients in groups A1 and A2 as well as groups B2 and A were not statistically significant. Clinical outcomes were similar for patients in groups B2 and A1 versus group A2., Conclusion: Time to return to activity and clinical outcomes after ankle stabilization surgery using the modified lasso-loop technique were negatively affected if simultaneous bilateral surgery or simultaneous concurrent procedures were added or if weight bearing was unrestricted. However, a delay in return to athletic activity was observed when ankle stabilization surgery was performed using the modified lasso-loop technique with concurrent procedures that require non-weight bearing postoperatively., Level of Evidence: Level III.

Purpose: Ligamento-muscular reflex pattern following stimulation of the anterior talofibular ligament (ATFL) was examined., Methods: The peroneus longus (PL), the tibialis anterior (TA), and tibialis posterior (TP) muscles were investigated in sixteen patients with functional ankle instability (FAI) and 16 age- and gender-matched controls. The ATFL was stimulated with a fine wire electrode while electromyographic (EMG) activities were recorded during isometric foot contraction of 20% maximal force in plantarflexion, dorsiflexion, supination and pronation. The complete measurement was repeated after a peroneal block anesthesia., Results: Statistically significant changes in post-stimulus EMG activity were observed in all three muscles and all four tested foot positions. In supination, the PL showed no reactions in both groups before and after anesthesia. The post-stimulus inhibition of the TA seen after 80 and 180 ms disappeared in controls after anesthesia. The TP had similar inhibitory responses in both groups., Conclusion: Ligamento-muscular reflex pattern is alterated in FAI. While early reactions are essential in protecting the ankle joint in sudden movements, the later responses indicate a supraspinal control of neuromuscular stability of the ankle joint. Proprioceptive rehabilitation of the PL, TA, and TP is crucial in FAI to compensate for post-traumatic ligamentomuscular reflex deficiencies., Level of Evidence: II.

Purpose: The angle between the anterior talofibular ligament (ATFL) and the posterior talofibular ligament (PTFL) is increased in patients with chronic ATFL injury. This study aimed to compare the AFTL-PTFL angle before versus after ankle lateral stabilization surgery, and to evaluate whether the ATFL-PTFL angle correlates with the ligament injury severity., Methods: This retrospective study included 48 patients with mechanical ankle instability treated between 2016 and 2018. After arthroscopic evaluation, all patients underwent ankle lateral stabilization surgery comprising ligament repair (n = 28) or reconstruction (n = 20). The ATFL-PTFL angle was measured in the axial plane on pre- and postoperative MRI. Comparisons were made of the pre- versus postoperative ATFL-PTFL angles, and the ATFL-PTFL angle of the repair versus reconstruction groups. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of the ATFL-PTFL angle in selecting the surgical technique., Results: The postoperative ATFL-PTFL angle was significantly decreased compared with preoperatively. The ATFL-PTFL angle was significantly smaller in the repair group than the reconstruction group preoperatively and postoperatively. The area under the ROC curve was 0.741 (P < 0.01). The optimal cutoff point for the selection of ligament reconstruction was an ATFL-PTFL angle of 89.4° (sensitivity 0.85, specificity 0.61)., Conclusion: The ATFL-PTFL angle decreases after ankle lateral stabilization surgery. The ATFL-PTFL angle is related to the severity of the ATFL injury. Ankle lateral ligament reconstruction should be considered when the ATFL-PTFL angle is > 89.4°., Level of Evidence: Level III.

Context: Approximately 72% of patients with an ankle sprain report residual symptoms 6 to 18 months later. Although 44% of patients return to activity in less than 24 hours after experiencing a sprain, residual symptoms should be evaluated in the long term to determine if deficits exist. These residual symptoms may be due to the quality of ligament tissue and motion after injury., Objective: To compare mechanical laxity of the talocrural joint and dorsiflexion range of motion (DFROM) over time (24 to 72 hours, 2 to 4 weeks, and 6 months) after an acute lateral ankle sprain (LAS)., Design: Cross-sectional study., Setting: Athletic training research laboratory., Patients or Other Participants: A total of 108 volunteers were recruited. Fifty-five participants had an acute LAS and 53 participants were control individuals without a history of LAS., Main Outcome Measure(s): Mechanical laxity (talofibular interval and anterior talofibular ligament length) was measured in inversion (INV) and via the anterior drawer test. The weight-bearing lunge test was conducted and DFROM was measured. The data were analyzed using repeated-measures analysis of variance, independent-samples t tests, and 1-way analysis of variance., Results: Of the 55 LASs, 21 (38%) were grade I, 27 (49%) were grade II, and 7 (13%) were grade III. Increases were noted in DFROM over time, between 24 and 72 hours, at 2 to 4 weeks, and at 6 months (P < .05). The DFROM was less in participants with grade III than grade I LASs (P = .004) at 24 to 72 hours; INV length was greater at 24 to 72 hours than at 2 to 4 weeks (P = .023) and at 6 months (P = .035) than at 24 to 72 hours. The anterior drawer length (P = .001) and INV talofibular interval (P = .004) were greater in the LAS group than in the control group at 6 months., Conclusions: Differences in range of motion and laxity were evident among grades at various time points and may indicate different clinical responses after an LAS., (© by the National Athletic Trainers' Association, Inc.)

Background: The purpose of the present study was to examine the relationship between ankle joint laxity and general joint laxity (GJL) in relation to the menstrual cycle, which was divided into four phases based on basal body temperature and ovulation, assessed using an ovulation kit., Methods: Participants were 14 female college students (21-22 years) with normal menstrual cycles (cis gender). Anterior drawer stress to a magnitude of 120 N was applied for all participants. Anterior talofibular ligament (ATFL) length was measured as the linear distance (mm) between its points of attachment on the lateral malleolus and talus using ultrasonography. Data on ATFL length from each subject were used to calculate each subject's normalized length change with anterior drawer stress (AD%). The University of Tokyo method was used for evaluation of GJL. AD% and GJL were measured once in each menstrual phase., Results: There was no statistically significant difference between AD% in each phase. GJL score was significantly higher in the ovulation and luteal phases compared with the early follicular phase. AD% and GJL showed a positive correlation with each other in the ovulation phase., Conclusions: Although it is unclear whether estrogen receptors are present in the ATFL, the present study suggests that women with high GJL scores might be more sensitive to the effects of estrogen, resulting in ATFL length change in the ovulation phase.

Background: Repetitive microtrauma can result in a hypertrophied ATFL. Previous studies have found that the anterior talofibular ligament thickness (ATFLT) is correlated with lateral ankle sprains, ligament injuries and chronic stroke in patients, and thickened anterior talofibular ligament (ATFL) has been considered to be a major morphologic parameter of hypertrophied ATFL. However, hypertrophy is different from thickness. Thus, we devised the anterior talofibular ligament area (ATFLA) as a new morphological parameter to evaluate the hypertrophy of the whole ATFL., Methods: ATFL samples were collected from 53 patients with sprain group and from 50 control subjects who underwent magnetic resonance imaging (MRI) of the ankle and revealed no evidence of lateral ankle injury. Axial T1-weighted MRI images were collected at the ankle level from all subjects. We measured the ATFLA and ATFLT at the anterior margin of the fibular malleolus to the talus bone on the MRI using a picture archiving and communications system. The ATFLA was measured as the whole cross-sectional ligament area of the ATFL that was most hypertrophied in the axial MR images. The ATFLT was measured as the thickest point between the lateral malleolus and the talus of the ankle., Results: The average ATFLA was 25.0 ± 6.0 mm 2 in the control group and 47.1 ± 10.4 mm 2 in the sprain group. The average ATFLT was 2.3 ± 0.6 mm in the control group and 3.8 ± 0.6 mm in the hypertrophied group. Patients in sprain group had significantly greater ATFLA (p < 0.001) and ATFLT (p < 0.001) than the control subjects. A Receiver Operator Characteristics curve analysis showed that the best cut-off point of the ATFLA was 34.8 mm 2 , with 94.3% sensitivity, 94.0% specificity, and an AUC of 0.97 (95% CI, 0.94-1.00). The optimal cut-off point of the ATFLT was 3.1 mm, with 86.8% sensitivity, 86.0% specificity, and AUC of 0.95 (95% CI, 0.92-0.99)., Conclusion: ATFLA is a new morphological parameter for evaluating chronic ankle sprain, and may even be more sensitive than ATFLT., (Copyright © 2019 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Purpose: The purpose of the present study was to compare the outcomes of patients who underwent augmented direct anatomical repair using a Broström-Gould procedure with those who underwent lateral ligament reconstruction using a split peroneus brevis tendon for the treatment of chronic ankle instability., Methods: Forty patients aged 18-40 years underwent surgical treatment for chronic lateral ankle instability between 1997 and 1998: 20 patients underwent direct anatomical repair using Broström-Gould procedure (Group A); 20 patients underwent lateral tenodesis using a split peroneus brevis tendon (Group B). Median age at surgery was 22.6 years (range 18-40). Patients were assessed pre-operatively and 15 years after surgery with functional assessment including AOFAS scale, Karlsson-Peterson score, Tegner activity level, Sefton stability scale, and objective examination comprehending ROM, anterior drawer sign and talar tilt test. Telos Stress equipment was used for pre- and post-operative radiographic laxity testing., Results: No major complications were reported. Mean overall AOFAS, Karlsson-Peterson and Tegner scores significantly increased at follow-up compared to pre-operatory status, although no statistically significant differences concerning these variables were reported between the two groups. Sagittal ROM was full in 36 patients: 4 subjects in the Group B experienced 5 degrees dorsiflexion limitation compared to the contralateral side. Patients treated with lateral tenodesis reported a statistically significant reduction in the values of radiographic anterior talar translation (1.4 mm, SD: 0.9) compared to patients in Group A (5.7 mm, SD: 1.1, p < 0.001)., Conclusion: Augmented direct anatomical repair and lateral tenodesis provide satisfying long-term outcomes in terms of subjective and objective parameters up to 15 years from surgery in patients with chronic ankle instability without leading to significant artrhitic changes. Objectively, lateral tenodesis appears to improve more effectively restoration of laxity; the reduced ROM reported in 20% of patients did not considerably affect the overall functional outcome., Level of Evidence: Comparative case series, Level III.

Lateral ankle instability is a debilitating condition that is often unresponsive to conservative therapy. Many techniques for operative repair have been proposed, most commonly performed as the Broström or modified Broström procedure. In patients with failed primary repair, hereditary collagen disorders, strenuous work activity, obesity, or ligamentous laxity, the Broström repair is less likely to be successful, and anatomic or nonanatomic reconstruction should be considered. The purpose of this study was to compare the functional outcomes and patient satisfaction between anatomic and nonanatomic reconstruction of the lateral ankle ligament complex for lateral ankle instability using a retrospective cohort study. We evaluated 64 ankles in 62 patients who underwent either a split peroneus brevis tendon (n = 36) or semitendinosus allograft tendon reconstruction (n = 28) for lateral ankle instability performed by the same surgeon. Postoperative American Orthopedic Foot and Ankle Society (p = .943) and patient satisfaction (p = .279) found no significant difference between either technique. Our results suggest that both split peroneus brevis and semitendinosus allograft may be viable alternatives for lateral ankle instability when primary ligamentous repair is not attainable., (Copyright © 2019 the American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The etiology and incidence of os trigonum syndrome in professional athletes is highly variable. There is a paucity of data to ascertain why some athletes evolve towards surgery whilst others remain asymptomatic. We hypothesized that a lateral ligament ankle injury would increase the likelihood for surgery in those athletes with os trigonum syndrome., Methods: Eighty professional athletes with clinical and radiological signs of os trigonum syndrome were identified to ascertain the incidence of injury to the lateral ligamentous ankle complex (acute and chronic) by magnetic resonance imaging (MRI). This cohort was subdivided into 2 groups; a surgical (n = 40) and a non-surgical (n = 40) cohort. Surgical division was decided if (1) the clinical hyper-plantar flexion test was positive, (2) a positive diagnostic ultrasound-guided injection and (3) no improvement was observed after 6 weeks of conservative rehabilitation., Results: From the surgical cohort, 37 players (94.1%) had a chronic lateral ankle ligament injury on MRI, whilst 3 players (5.9%) had an acute lateral ankle ligament injury. Binary logistic linear modelling revealed that having a chronic lateral ligament injury increases the likelihood of os trigonum syndrome surgery by ten times compared to those with an acute lateral ligament injury., Conclusion: Professional athletes with chronic lateral ligament ankle injury have an approximate ten times greater risk for os trigonum syndrome surgery compared to athletes with acute lateral ligament ankle injury., Level of Evidence: IV.

Objective: Accurate identification of distal tibio-fibular syndesmotic injuries is essential to limit potential deleterious post-traumatic effects. To date, conventional radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) have shown limited utilization. This cadaver study evaluates the utility of weight-bearing CT scans on the assessment of incomplete and more complete syndesmotic injuries., Materials and Methods: Ten male cadavers (tibial plateau to toe-tip) were included. Weight-bearing CTs were taken under four test conditions, with and without torque on the tibia (corresponding to external rotation of the foot and ankle). First, intact ankles (native) underwent imaging. Second, the anterior-inferior tibio-fibular ligament (AITFL) was transected (condition 1). Then, the deltoid ligament (condition 2) was transected, followed by the interosseous membrane (IOM, condition 3). Finally, the posterior-inferior tibio-fibular ligament (PITFL) was transected (condition 4). The medial clear space (MCS), the tibio-fibular clear space (TFCS), and the tibio-fibular overlap (TFO) were assessed on digitally reconstructed radiographs (DRRs), and on axial CT images., Results: The TFO differentiated isolated AITFL transection from native ankles when torque was applied. Also under torque conditions, the MCS was a useful predictor of an additional deltoid ligament transection, whereas the TFCS identified cadavers in which the PITFL was also transected., Conclusion: Torque application helps to diagnose incomplete syndesmotic injuries when using weight-bearing CT. The TFO may be useful for identifying incomplete syndesmotic injuries, whereas the MCS and TFCS predict more complete injuries.

The goal of this meta-analysis was to explore the overall safety and efficacy of surgical therapy vs conservative therapy for acute injury of the lateral ankle ligament based on eligible studies. Eligible studies were identified by searching PubMed, Cochrane, and Embase databases using appropriate updated index words to January 2018. We also searched relevant publication sources. Eligible studies included randomised controlled trials and comparative studies. Mean difference or relative risk (RR), along with 95% confidence interval (CI), was used to analyse the main outcomes. A total of 13 studies were eligible for this meta-analysis, with 834 patients in the surgical therapy group and 930 patients in the conservative therapy group. Compared with patients receiving conservative treatment, patients undergoing surgical treatment had a significant higher American Orthopedic Foot And Ankle Society (AOFAS) score (weighted mean difference(WMD): 10.33, 95% CI: 6.83-13.83) and an effective rate (RR: 1.15, 95% CI: 1.04-1.28). No significant differences were observed in the incidence of recurrent ankle injury (RR: 1.01, 95% CI: 0.62-1.65), limited range of motion (RR: 1.44, 95% CI: 0.83-2.50), deep vein thrombosis (RR: 1.33, 95% CI: 0.73-2.41), and wound infection or necrosis (RR: 3.99, 95% CI: 0.45-35.34). However, compared with patients receiving conservative treatment, patients undergoing surgical therapy had significantly increased rates of complications (RR: 3.31, 95% CI: 2.55-4.28), ankylosis (RR: 3.63, 95% CI: 2.16-6.08), scare tenderness (RR: 10.16, 95% CI: 3.89-26.52) and sensory loss (RR: 5.66, 95% CI: 2.76-11.59). The results demonstrated that surgical treatment increased the AOFAS score and effective rate compared with conservative treatment. Besides, surgical treatment increased the rate of complications. Nevertheless, more high-quality randomised controlled trials with a larger sample size conducted at multiple centres with a long-term follow up are needed to confirm our conclusions., (© 2019 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Objective: To compare the clinical and radiological outcome between the modified Broström repair with augmentation using suture tape (MBA) and the modified Broström repair (MB) for patients with chronic lateral ankle instability., Methods: A retrospective study was performed in Ningbo No. 6 Hospital. The study included 53 patients who underwent surgical treatment from March 2014 to July 2016 and were followed for 2 years. A total of 25 patients underwent modified Broström repair with augmentation using suture tape, and 28 patients were treated with modified Broström repair. Patients were evaluated using the American Orthopedic Foot and Ankle Scale (AOFAS) hindfoot scale, the Foot and Ankle Ability Measure (FAAM) score, range of motion (ROM), and the visual analogue scale (VAS). The talar tilt angle (TTA) and anterior talar translation (ATT) were used to evaluate the mechanical stability. All radiological outcomes were measured by two orthopaedic surgeons, with the measurements repeated 3 days later., Results: The mean age of the patients was 26.6 ± 17.8 years in the MBA group and 28.1 ± 19.4 years in the MB group, and no statistical difference in preoperative data was found between two groups. There were significant differences before and after the operation within the groups. Both groups achieved satisfactory outcomes, and significant improvements (VAS, FAAM, AOFAS, TTA, and ATT) were observed between the 1-year follow-up and final follow-up (P < 0.05). The MBA group showed significant improvement in the FAAM Sport (87.1 ± 5.4 vs 78.2 ± 12.0, P = 0.001) and total scores (93.1 ± 2.3 vs 90.5 ± 5.1, P = 0.027) at the final follow-up compared with the MB group, and for the other outcomes, there were no significant differences between the two groups., Conclusion: The modified Broström repair with augmentation using suture tap for chronic lateral ankle instability achieves a better outcome; however, further research is necessary., (© 2019 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

Lateral ankle sprains (LASs) are among the most common injuries incurred during participation in sport and physical activity, and it is estimated that up to 40% of individuals who experience a first-time LAS will develop chronic ankle instability (CAI). Chronic ankle instability is characterized by a patient's being more than 12 months removed from the initial LAS and exhibiting a propensity for recurrent ankle sprains, frequent episodes or perceptions of the ankle giving way, and persistent symptoms such as pain, swelling, limited motion, weakness, and diminished self-reported function. We present an updated model of CAI that aims to synthesize the current understanding of its causes and serves as a framework for the clinical assessment and rehabilitation of patients with LASs or CAI. Our goal was to describe how primary injury to the lateral ankle ligaments from an acute LAS may lead to a collection of interrelated pathomechanical, sensory-perceptual, and motor-behavioral impairments that influence a patient's clinical outcome. With an underpinning of the biopsychosocial model, the concepts of self-organization and perception-action cycles derived from dynamic systems theory and a patient-specific neurosignature, stemming from the Melzack neuromatrix of pain theory, are used to describe these interrelationships.

Background: Chronic ankle instability (CAI) may result from repeated, frequent ankle sprains during sports activities. Manual examination for CAI is conducted; however, quantitative methods for the evaluation of CAI have not been established, and the reproducibility of the amount of stress is low. This cross-sectional study aimed to use a stress device and ultrasound for the quantitative evaluation of the change in the length of the anterior talofibular ligament (ATFL) during simulated anterior drawer and ankle inversion stress tests., Methods: Questionnaires were provided to 160 healthy college students (86 men, 74 women; 320 ankles). We extracted two groups from them: control subjects without a history of ankle injury ( n  = 64 ankles) and subjects with CAI ( n  = 54 ankles). We calculated the change in the length of the ATFL with anterior drawer and inversion stress tests at ankle joint plantar flexions of 0°, 20°, and 45° using ultrasound images., Results: The anterior length change rates were significantly higher in the CAI group than in the control group at ankle joint plantar flexions of 20° and 45° in men ( P  < 0.05). The inversion length change rates were significantly higher in the CAI group at ankle joint plantar flexion of 20° in men ( P  < 0.05). No significant between-group difference in the anterior and inversion length change rates was observed in women., Conclusions: Stress ultrasound revealed greater length changes in the ATFL in the CAI group than in the control group. The stress test may be useful at ankle joint plantar flexion of 20° for men., Competing Interests: The study protocol was approved by the institutional review board of Niigata University of Health and Welfare (no. 17798–170285). Written informed consent was obtained from each subject.Not applicable.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Background:: Although lateral ligament augmentation using suture-tape has been effective for restoration of mechanical ankle stability, few data are available regarding changes of peroneal strength, proprioception, and postural control. The aim of this study was to determine effects of suture-tape augmentation on functional ankle instability (FAI)., Methods:: Twenty-four patients who underwent suture-tape augmentation were eligible and were followed more than 2 years postoperatively. Functional outcomes were evaluated with the Cumberland Ankle Instability Tool (CAIT), Foot and Ankle Ability Measure (FAAM). Changes of peroneal strength, proprioception and postural control were analyzed with an isokinetic dynamometer and a modified Romberg test., Results:: CAIT and FAAM (average of daily and sports activity scores) significantly improved to average 27.2 points and 86.7 points, respectively, at final follow-up. Peak torque for eversion in 60 degrees/s angular velocity significantly improved to 10.6 Nm at final follow-up. Deficit ratio of peak torque for eversion significantly improved from mean 39.5% to 20.9%, and significant side-to-side difference was revealed ( P < .001). There were no significant differences in joint position sense. A significant improvement in balance retention time was revealed at final follow-up, and the relative deficit ratio compared to the unaffected side was 30.9%., Conclusions:: Patient-reported functional outcomes significantly improved after lateral ligament augmentation using suture-tape. Although this procedure demonstrated significant effects on FAI based on improvement of isokinetic peroneal strength and postural control, recovery rates compared to the unaffected side were not significant at the intermediate-term follow-up. In addition, there was no positive effect on proprioception of the ankle., Level of Evidence:: Level IV, prospective case series.

Lateral hindfoot pain associated with stage 2 to 3 adult-acquired flatfoot is often attributed to subfibular impingement. Preoperative magnetic resonance imaging (MRI) is generally performed to assess the extent of degeneration within the posterior tibial tendon, attenuation of medial soft tissue constraints, and degeneration of hindfoot and/or ankle articulations. The purpose of this study is to determine the incidence of lateral collateral ligament disease/injury associated with stages 2 and 3 adult-acquired flatfoot. The subjects were identified using a searchable computerized hospital database between 2015 and 2017. Stage 2 or 3 adult-acquired flatfoot deformity was confirmed in patients via chart review and MRI analysis. Lateral ankle ligament injury was confirmed using patient MRI results per the hospital radiologist and documented within the patients' chart. Inclusion criteria required that patients be diagnosed with Johnson and Strom stage 2 or 3 flatfoot deformity with documented lateral ankle pain and that preoperative MRI scans be available with the radiologist's report. Patient exclusion criteria included patients <18 years of age, patients with flatfoot deformity caused by previous trauma, tarsal coalition, neuropathic arthritis, patients with previous surgery, or patients with incomplete medical records. In total, 118 patients were identified with these parameters. Of the 118 patients, 74 patients (62.7%) had documented lateral ankle ligament injury on MRI. Of the 77 patients with stage 2 adult-acquired flatfoot, 55 (71.4%) had confirmed lateral ankle ligament injury on MRI. Of the 41 patients with stage 3 adult-acquired flatfoot, 19 (46.3%) had confirmed lateral ankle ligament injury on MRI. This study demonstrates a relatively high incidence of lateral ligament disease associated with adult-acquired flatfoot deformity. These findings might have long-term implications regarding ankle arthritis after surgical management of adult-acquired flatfoot., (Copyright © 2018 the American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Background. Both percutaneous and arthroscopic techniques have been introduced in anatomic ankle lateral ligaments reconstruction. The purpose of this study was to compare these two techniques in identifying the calcaneal insertion of the calcaneofibular ligament (CFL). Methods. Fifteen fresh-frozen human ankle cadaver specimens were used in this study. Each specimen was tested in three stages. For stage 1, each specimen was evaluated under arthroscopy. After debridement was performed, the insertion of the CFL on the calcaneus was identified, and a 1.5mm Kirschner wire was drilled at the center of the insertion. For stage 2, a percutaneous technique was used to identify the center of the insertion of the CFL. A second 1.5 mm Kirschner wire was drilled through the skin marker. For stage 3, the ankle was dissected, the footprint of the CFL was identified under direct vision, and the distances between the center of the CFL insertion on the calcaneus and the two Kirschner wires were measured, respectively. Results. In the arthroscopic technique group, the mean distance from the Kirschner wire to the center of the CFL insertion in the calcaneus was 3.4 ± 1.3 mm. In the percutaneous technique group, the mean distance from the Kirschner wire to the center of the CFL insertion was 3.2 ± 1.4 mm. No significant difference was found between the two groups. Conclusion. No difference in identifying the calcaneal insertion of the CFL was found between the percutaneous and the arthroscopic ankle lateral ligaments reconstruction technique. Both techniques can be used during anatomic ligaments reconstruction in treatment of chronic ankle instability.

The clinical diagnosis of the anterior talofibular ligament (ATFL) rupture is based on the findings from the medical history and the anterior drawer test, a maneuver that allegedly pushes the talus and rearfoot anteriorly, although with great variability in its sensitivity. We consider that an ATFL rupture is best evaluated by a rotational vector (i.e., a pivot test) owing to the uncompromised medial ligaments that will block any pure anterior translation of the talus underneath the tibia. We idealized a constrained ankle cadaver model that only allows talar movements in the axial plane. Our hypothesis was that progressive sectioning of the lateral ankle ligaments in this model would cause a progressive and significant angular laxity in internal rotation. Our results showed 3.67 degrees ± 1.2 degrees of talus rotational laxity in the intact ankle, 9.6 degrees ± 3.2 degrees after ATFL sectioning, and 13.43 degrees ± 3.2 degrees after ATFL and calcaneofibular ligament sectioning, indicating almost threefold increase in internal talocrural rotation after single ATFL sectioning and an almost fourfold increase after double (ATFL and calcaneofibular ligament) sectioning. We consider this evidence of rotational ankle laxity to be a major step in defining the correct movement to diagnose an ATFL rupture and propose a new term to avoid further inconsistencies and variability, "the pivot test.", (Copyright © 2018 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Although a variety of surgical procedures for lateral ankle ligament reconstruction have frequently been reported, little is known about the effects of initial graft tension. Purpose/Hypothesis: The purpose was to investigate the effects of initial graft tension in calcaneofibular ligament (CFL) reconstruction. It was hypothesized that a high degree of initial graft tension would cause abnormal kinematics, laxity, and excessive graft tension., Study Design: Controlled laboratory study., Methods: Twelve cadaveric ankles were tested with a 6 degrees of freedom robotic system to apply passive plantarflexion-dorsiflexion motion and multidirectional loads. A repeated-measures experiment was designed with the CFL intact, CFL transected, and CFL reconstructed with 4 initial tension conditions (10, 30, 50, and 70 N). The 3-dimensional path and reconstructed graft tension were simultaneously recorded., Results: The calcaneus in CFL reconstruction with an initial tension of 70 N had the most eversion relative to the intact condition (mean eversion translations of 1.2, 3.0, 5.0, and 6.2 mm were observed at initial tensions of 10, 30, 50, and 70 N, respectively). The calcaneus also moved more posteriorly with external rotation as the initial tension increased. The reconstructed graft tension tended to increase as the initial tension increased., Conclusion: Ankle kinematic patterns and laxity after CFL reconstruction tended to become more abnormal as the initial graft tension increased at the time of surgery. Moreover, excessive initial graft tension caused excessive tension on the reconstructed graft., Clinical Relevance: This study indicated the importance of initial graft tension during CFL reconstruction. Overtensioning during CFL reconstruction should be avoided to imitate a normal ankle.

Introduction: Precise diagnosis of distal tibiofibular syndesmotic injury is challenging, and a gold standard diagnostic test has still not been established. Tibiofibular clear space identified on radiographic imaging is considered the most reliable indicator of the injury. The Cotton test is the most widely used intraoperative technique to evaluate the syndesmotic integrity although it has its limitations. We advocate for a novel intra operative test using a 3.5 mm blunt cortical tap., Methods: Tibiofibular clear space was assessed in nine cadaveric specimens using three sequential fluoroscopic images. The first image was taken prior to the application of the tap test (intact, non-stressed). Then, a 2.5 mm hole was drilled distally on the lateral fibula, and a 3.5 mm cortical tap was then threaded in the hole. The tap test involved gradually advancing the blunt tip against the lateral tibia, providing a tibiofibular separation force (intact, stressed). This same stress was then applied after all syndesmotic ligaments were released (injured, stressed). Measurements were compared by one-way ANOVA and paired Student's t-test. Intra and inter-observer agreements were evaluated by intraclass correlation coefficient (ICC). P-values <.05 were considered significant., Results: We found excellent intra-observer (0.97) and inter-observer (0.98) agreement following the imaging assessment. Significant differences were found in the paired comparison between the groups (p < .05). When using an absolute value for TFCS >6 mm as diagnostic for coronal syndesmotic instability, the tap test demonstrated a 96.3% sensitivity and specificity, a 96.3% PPV and NPV and a 96.3% accuracy in diagnosing coronal syndesmotic instability., Conclusions: Our cadaveric study demonstrated that this novel coronal syndesmotic instability test using a 3.5 mm blunt cortical tap is a simple, accurate and reliable technique able to demonstrate significant differences in the tibiofibular clear space when injury was present. It could represent a more controlled and stable alternative to the most used Cotton test., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: The deltoid ligament (DL) is the principal ligamentous stabilizer of the medial ankle joint. Little is known, however, about the contribution of the DL toward stabilizing the syndesmosis. The aim of this study was to arthroscopically evaluate whether the DL contributes to syndesmotic stability in the coronal plane., Methods: Eight above-knee cadaveric specimens were used in this study. A lateral hook test was performed by applying 100 N of lateral force to the fibula in the intact state and after sequential transection of the DL, anterior-inferior tibiofibular ligament (AITFL), interosseous ligament (IOL), and posterior-inferior tibiofibular ligament (PITFL). At each stage, distal tibiofibular diastasis was measured arthroscopically at both the anterior and posterior third of the incisura and compared to stress measurements of the intact syndesmosis. Measurements were performed using probes ranging from 0.1 to 6.0 mm, with 0.1-mm increments., Results: There was no significant increase in diastasis at either the anterior or posterior third of the tibiofibular articulation after isolated DL disruption, nor when combined with AITFL transection. In contrast, a significant increase in diastasis was observed following additional disruption of the IOL (anterior and posterior third diastasis, P= .012 and .026, respectively), and after transection of all 3 syndesmotic ligaments (anterior and posterior third diastasis, P=.001 and .001, respectively)., Conclusion: When evaluating the syndesmosis arthroscopically in a cadaveric model under lateral stress, neither isolated disruption of the DL nor combined DL and AITFL injuries destabilized the syndesmosis in the coronal plane. In contrast, the syndesmosis became unstable if the DL was injured in conjunction with partial syndesmotic disruption that included the AITFL and IOL., Clinical Relevance: Disruption of the DL appeared to destabilize the syndesmosis in the coronal plane when associated with partial disruption of the syndesmosis (AITFL and IOL).

Background: Ligament repair and augmentation techniques can stabilize syndesmosis injuries. However, little is known about the mechanical behavior of syndesmotic ligaments. The aim of this study was to analyze full-field strain, strain trend under foot rotation, and subregional strain differences of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), and interosseous membrane (IOM)., Methods: Eleven fresh-frozen lower limbs were dissected to expose the AITFL, PITFL, and IOM. The foot underwent rotation from 0° to 25° internal and 35° external, with 3 ankle positions (neutral, 15° dorsiflexion, and 25° plantarflexion) and a vertical load of 430 N. Ligament strain was recorded using digital image correlation., Results: The mean strain on the AITFL with 35° external rotation was greater in the proximal portion compared with distal portion in the neutral position ( P = .009) and dorsiflexion ( P = .003). The mean strain in the tibial insertion and midsubstance near tibial insertion were greater when compared with other regions ( P = .018 and P = .009). The subregions of mean strain in the PITFL and IOM groups were not significantly different. The strain trend of AITFL, PITFL, and IOM showed common transformation, just when the foot was externally rotated., Conclusion: The findings of this study show that a significantly high strain was observed on the proximal part and the midsubstance near the Chaput tubercle of the AITFL when the ankle was externally rotated. All 3 ligaments resisted the torque in the syndesmosis by external rotation of the foot., Clinical Relevance: This study allows for better understanding of the mechanical behavior of the syndesmosis ligaments, which could influence the repair technique and AITFL augmentation techniques.

Chronic lateral ankle instability causes significant problems with physical activity. The purpose of the present study was to evaluate the results of ligamentous retensioning combined with reinforcement using an extensor retinaculum flap. A consecutive series of 38 patients were included with a minimum follow-up duration of 2 years. The functional results were assessed using the Karlsson and American Orthopaedic Foot and Ankle Society scale scores. The pre- and postoperative radiologic assessment was performed using stress radiographs to measure varus tilt and anterior drawer tests. All 38 patients were followed up for 2.5 to 7.2 years, and 35 patients were satisfied. The American Orthopaedic Foot and Ankle Society scale score had improved significantly from 57 (range 20 to 70) points preoperatively to 95 (range 80 to 100) points postoperatively (p < .0001), and 35 patients believed their ankle was more stable after surgery. The patients had returned to their previous sports activities an average of 4.7 (range 2 to 12) months after surgery. On the stress radiographs, the mean talar tilt angle had improved significantly from 15.2° (range 6° to 26°) preoperatively to 3.8° (range 1° to 8°) at the final follow-up visit (p < .001), and the mean anterior talar had improved significantly from 13.2 (range 8 to 18) mm preoperatively to 4 (range 4 to 7) mm at the final follow-up visit (p < .002). Regarding the prognostic factors, a link was found between the functional result and residual radiologic laxity measured on the stress radiographs. Reconstruction of the lateral ligaments for chronic ankle instability combining capsuloligamentous retensioning and reinforcement with an extensor retinaculum flap resulted in successful outcomes, excellent ankle stability, and preservation of ankle joint mobility. This technique addressed both lateral ankle and subtalar instability by developing an extraarticular interosseous ligament., (Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The Broström procedure is the most commonly used lateral ligament repair for chronic instability, but there is concern about the strength of the repair and the risk of reinjury. Currently, the InternalBrace TM ligament augmentation repair is an accepted augmentation method for management of a Broström procedure. Our hypothesis was that augmentation of the Broström repair with an InternalBrace TM would allow accelerated rehabilitation and return to activity and would aid in stability of the repair without a tendency to stretch., Methods: Eighty-one patients with lateral ankle instability procedures repaired with a Broström and InternalBrace TM augmentation were evaluated at a one-time postoperative visit between 6 and 24 months. Outcomes included demographics, surgical time, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot score, Veterans Rand 12-Item Health Survey (VR-12), Foot and Ankle Ability Measure (FAAM), Visual Analog Scale (VAS), satisfaction, and objective clinical measurements. Eighty-one patients were analyzed including 30 males and 51 females. Median age was 34 years (range, 18-62 years) with a median return for follow-up of 11.5 months (range, 6-27 months)., Results: Average postoperative VAS and satisfaction were 0.8 ± 1.4 and 9.1 ± 1.6, respectively. Mean return to sport (n = 68) was 84.1 days. Average AOFAS Ankle-Hindfoot score was 94.3. A score of 90 or higher on the FAAM Sports subscale was seen in 79.0% of the subjects. The single-leg hop test (Limb Symmetry Index %) showed that 86.4% of patients returned to normal or near normal function. The tape measure method and ankle dorsiflexion comparisons showed a significant difference: 9.2 ± 3.3 cm (operative side) and 10.4 ± 3.7 cm (contralateral side) ( P = .034). Ankle plantar flexion comparison (goniometer) was 48.5 ± 11.5 degrees (operative side) and 49.7 ± 11.9 degrees (contralateral side), showing no difference ( P = .506)., Conclusion: These results suggest that InternalBrace TM augmentation of a Broström procedure is a safe and efficacious procedure that produces favorable outcomes in patients in terms of preventing recurrent instability in the ankle in the short term., Level of Evidence: Level IV, case series.

Context:   Ankle sprains are the most common orthopaedic injury that occurs during sport and physical activity. Many individuals who sprain their ankles develop chronic ankle instability (CAI), a condition characterized by recurrent injury, decreased physical activity, and decreased quality of life. These residual impairments are believed to persist for the remainder of the patient's life, in part due to the link between CAI and posttraumatic ankle osteoarthritis. However, this belief remains speculative due to the lack of long-term prospective investigations., Objective:   To use a mouse model of mild (MILD) and severe (SEVERE) ankle sprains to quantify balance and locomotor adaptations across the lifespan., Design:   Cohort study., Setting:   University research laboratory., Patients or Other Participants:   Fifty male mice (CBA/J) were randomly placed into a control (SHAM), MILD, or SEVERE group and housed individually., Intervention(s):   The MILD group underwent surgical transection of a single right hind-limb lateral ankle ligament, and the SEVERE group had 2 of the lateral ligaments transected. The SHAM group underwent a sham surgery during which no lateral ligaments were transected., Main Outcome Measure(s):   After surgically inducing the ankle sprain, we measured balance and gait using a balance beam and footprint test before and every 6 weeks for 78 weeks., Results:   Age-related declines in balance but not stride length were exacerbated by an ankle sprain ( P < .001). Balance and stride lengths changed with age ( P < .001). Foot slips were worse in the SEVERE (4.32 ± 0.98) and MILD (3.53 ± 0.98) groups than in the SHAM group (2.16 ± 0.99; P < .001). Right-limb stride length was shorter in the SEVERE group (6.45 cm ± 0.41 cm) than in the SHAM group (6.87 cm ± 0.40 cm; P = .04)., Conclusions:   Transecting the lateral ligaments of a mouse hind foot resulted in lifelong sensorimotor dysfunction. Declines starting at 42 weeks postinjury may have represented the onset of posttraumatic osteoarthritis.

Background: The correct amount of external rotation of the femoral component during TKA is controversial because the resulting changes in biomechanical knee function associated with varying degrees of femoral component rotation are not well understood. We addressed this question using a computational model, which allowed us to isolate the biomechanical impact of geometric factors including bony shapes, location of ligament insertions, and implant size across three different knees after posterior-stabilized (PS) TKA., Questions/purposes: Using a computational model of the tibiofemoral joint, we asked: (1) Does external rotation unload the medial collateral ligament (MCL) and what is the effect on lateral collateral ligament tension? (2) How does external rotation alter tibiofemoral contact loads and kinematics? (3) Does 3° external rotation relative to the posterior condylar axis align the component to the surgical transepicondylar axis (sTEA) and what anatomic factors of the femoral condyle explain variations in maximum MCL tension among knees?, Methods: We incorporated a PS TKA into a previously developed computational knee model applied to three neutrally aligned, nonarthritic, male cadaveric knees. The computational knee model was previously shown to corroborate coupled motions and ligament loading patterns of the native knee through a range of flexion. Implant geometries were virtually installed using hip-to-ankle CT scans through measured resection and anterior referencing surgical techniques. Collateral ligament properties were standardized across each knee model by defining stiffness and slack lengths based on the healthy population. The femoral component was externally rotated from 0° to 9° relative to the posterior condylar axis in 3° increments. At each increment, the knee was flexed under 500 N compression from 0° to 90° simulating an intraoperative examination. The computational model predicted collateral ligament forces, compartmental contact forces, and tibiofemoral internal/external and varus-valgus rotation through the flexion range., Results: The computational model predicted that femoral component external rotation relative to the posterior condylar axis unloads the MCL and the medial compartment; however, these effects were inconsistent from knee to knee. When the femoral component was externally rotated by 9° rather than 0° in knees one, two, and three, the maximum force carried by the MCL decreased a respective 55, 88, and 297 N; the medial contact forces decreased at most a respective 90, 190, and 570 N; external tibial rotation in early flexion increased by a respective 4.6°, 1.1°, and 3.3°; and varus angulation of the tibia relative to the femur in late flexion increased by 8.4°, 8.0°, and 7.9°, respectively. With 3° of femoral component external rotation relative to the posterior condylar axis, the femoral component was still externally rotated by up to 2.7° relative to the sTEA in these three neutrally aligned knees. Variations in MCL force from knee to knee with 3° of femoral component external rotation were related to the ratio of the distances from the femoral insertion of the MCL to the posterior and distal cuts of the implant; the closer this ratio was to 1, the more uniform were the MCL tensions from 0° to 90° flexion., Conclusions: A larger ratio of distances from the femoral insertion of the MCL to the posterior and distal cuts may cause clinically relevant increases in both MCL tension and compartmental contact forces., Clinical Relevance: To obtain more consistent ligament tensions through flexion, it may be important to locate the posterior and distal aspects of the femoral component with respect to the proximal insertion of the MCL such that a ratio of 1 is achieved.

Background: Arthroscopic evaluation of the syndesmosis allows direct visualization of syndesmotic instability. The purpose of this study was to determine the minimum degree of ligamentous injury necessary to destabilize the syndesmosis in the coronal plane when assessed arthroscopically and pinpoint where such instability should be measured within the incisura., Methods: Fourteen cadaveric specimens were divided into 2 groups and arthroscopically assessed first with the syndesmosis intact and then following serial differential ligamentous transection. Group 1 (n = 7): anterior-inferior tibiofibular (AITFL), interosseous (IOL), posterior-inferior tibiofibular (PITFL), and deltoid (DL) ligament. Group 2 (n = 7): PITFL-IOL-AITFL-DL. At each step, a standard 100-N lateral hook test was applied and tibiofibular coronal plane diastasis measured arthroscopically at both the anterior and posterior third of the incisura. These measurements were in turn compared with those of the stressed intact ligamentous state., Results: There was no significant syndesmotic instability measured at either the anterior or posterior margin of the incisura after transection of a singular ligament (AITFL or PITFL) or after the IOL was additionally transected. Diastasis at the posterior margin was significantly increased when all syndesmotic ligaments were sectioned (group 1: P = .018; group 2: P = .008), but this was not noted along the anterior margin. Diastasis at the anterior margin reached significance only with complete transection of syndesmosis and DL (group 1: P < .001; group 2: P = .044)., Conclusion: Under arthroscopic evaluation, the syndesmosis becomes unstable in the coronal plane only when all syndesmotic ligaments are transected, which should preferentially be measured at the posterior margin of the incisura. Anteriorly, diastasis becomes apparent only with addition of DL disruption, although this added finding may aid in diagnosis of occult deltoid injury., Clinical Relevance: AITFL, IOL, and PITFL need to be injured to produce coronal plane syndesmotic instability. Arthroscopic assessment of such instability should occur along the posterior margin of the incisura. When they exist, similar findings anteriorly suggest concomitant deltoid injury.

Background: The modified Broström procedure (MBP) is widely accepted as the primary operative treatment for chronic lateral ankle instability (CLAI). However, the MBP does not produce good clinical results in all patients, and anatomic reconstruction using a free tendon graft may be considered in those patients. The purpose of this study was to evaluate the efficacy of the MBP using distal fibular periosteal flap augmentation for CLAI in patients who were not candidates for standard repair., Methods: Thirty-eight patients (39 ankles) who underwent surgery for CLAI were retrospectively analyzed. The patients were divided into 2 groups: an anatomic lateral ligament reconstruction group (reconstruction group) consisting of 17 ankles and an MBP group using distal fibular periosteal flap augmentation (augmentation group) consisting of 22 ankles. Preoperative and postoperative clinical evaluations were performed using the visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS), and Karlsson-Peterson (Karlsson) scores., Results: The mean VAS, AOFAS, and Karlsson scores significantly improved from 4.0 to 1.8, 54.7 to 92.9, and 46.4 to 92.7, respectively, in the reconstruction group ( P < .001, P < .001, P < .001), and from 4.1 to 1.5, 60.1 to 94.9, and 52.6 to 94.1, respectively, in the augmentation group ( P < .001, P < .001, P < .001). There were no significant differences in the mean postoperative AOFAS and Karlsson scores between the groups ( P = .214, P = .299)., Conclusion: The MBP using distal fibular periosteal flap augmentation was also an effective option for CLAI in cases of generalized ligament laxity, severe attenuation of the soft tissue, previous failed surgery, high demand activity, and obesity., Level of Evidence: Level III, comparative series.

Objective: To evaluate the feasibility of point-of-care ankle ultrasound compared with magnetic resonance imaging (MRI) for diagnosing major ligaments and Achilles tendon injuries in patients with recurrent ankle sprain and chronic instability, and to evaluate inter-observer reliability between an emergency physician and a musculoskeletal radiology fellow., Material and Methods: A prospective cross-sectional study was conducted in an emergency department. Patients with recurrent ankle sprain and chronic instability were recruited. An emergency physician and a musculoskeletal radiology fellow independently evaluated the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), distal anterior tibiofibular ligament (ATiFL), deltoid ligament, and Achilles tendon using point-of-care ankle ultrasound. Findings were classified normal, partial tear, and complete tear. MRI was used as the reference standard. We calculated diagnostic values for point-of-care ankle ultrasound for both reviewers and compared them using DeLong's test. Intra-class correlation coefficients (ICCs) were calculated for agreement between each reviewer and the reference standard, and between the two reviewers., Results: Eighty-five patients were enrolled. Point-of-care ankle ultrasound showed acceptable sensitivity (96.4-100%), specificity (95.0-100%), and accuracy (96.5-100%); these performance markers did not differ significantly between reviewers. Agreement between each reviewer and the reference standard was excellent (emergency physician, ICC=0.846-1.000; musculoskeletal radiology fellow, ICC=0.930-1.000), as was inter-observer agreement (ICC=0.873-1.000)., Conclusion: Point-of-care ankle ultrasound is as precise as MRI for detecting major ankle ligament and Achilles tendon injuries; it could be used for immediate diagnosis and further pre-operative imaging. Moreover, it may reduce the interval from emergency department admission to admission for surgical intervention, and may save costs., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To retrospectively evaluate the radiologic findings for predicting rehabilitation outcomes in patients with chronic symptomatic os subfibulare., Materials and Methods: 38 patients with chronic lateral ankle pain and os subfibulare underwent a standardized rehabilitation program. Rehabilitation outcome was evaluated after ≥3 months of intervention as the following: good response group (n = 20) without the need for further treatment and poor response group (n = 18) who underwent surgery after rehabilitation. Size, shape and location of os subfibulare, anterior talofibular ligament abnormality and attachment to the os subfibulare, interposition of fluid signal intensity between the os subfibulare and the fibula, and bone marrow edema in the os subfibulare on radiographs and MRI were evaluated by two radiologists blinded to rehabilitation outcomes and were compared between the two groups., Results: The mean size of os subfibulare was significantly different between good and poor response groups: 7 versus 12 mm (p < 0.01), respectively. The prevalence of interposition of fluid signal intensity between the os subfibulare and the fibula and bone marrow edema in the os subfibulare on MRI was significantly different between the two groups (p < 0.01). However, other radiologic findings were not significantly different (p ≥ 0.08). The optimal size to classify the two groups was 9 mm with sensitivity of 83.3% and specificity of 80%. Inter-observer reliability was good to excellent (ICC = 0.991 for size and kappa = 0.735-0.923 for others)., Conclusions: MRI may be used to predict rehabilitation outcome in patients with chronic symptomatic os subfibulare.

Background: Access to the plantar plate has been described using either a plantar approach or an extensive dorsal approach that required complete joint destabilization and often a metatarsal osteotomy. Clinical scenarios related to plantar plate tear vary and the pathologies in early stages are frequently limited to unilateral soft tissue structures; a less invasive operative approach may be possible. A novel approach requiring a release of only the lateral collateral ligament and the lateral half of the plantar plate is presented in this cadaver model; the extent of joint exposure possible is described. The ability to place a secure suture through the lateral collateral ligament and the plantar plate was analyzed., Methods: Nine fresh-frozen cadaveric specimens were dissected in a randomized fashion across the second to fourth metatarsophalangeal joints through the intermetatarsal space dorsally. Under distraction, soft tissue was sequentially released, including dorsal capsule, lateral collateral ligament, and the lateral half of the plantar plate. Integrity of the extensor tendons, deep transverse intermetatarsal ligament, proximal attachment of the plantar plate, and osseous structures was carefully preserved. The joint exposure was quantified after each step with sizing rods. Using a suture passer, 2-0 nonabsorbable braided sutures were passed into the lateral collateral ligament and the plantar plate, and the construct strength was measured using a tensiometer., Results: Progressive increase in mean joint exposure was noted after each step of soft tissue release with the final exposure of 6 mm after release of the lateral half of the plantar plate. Joint exposures after a capsulotomy and a lateral collateral release were 3 mm and 4 mm, respectively. Under distraction, the unilateral release of soft tissue created a lateral opening of the joint while the proximal phalangeal base adducted and medially deviated. Successful suture passage was noted in all specimens that could sustain a minimum tension of 25 N without a catastrophic failure. There was no statistically significant correlation with age, sex, foot length, and rays of the specimens when joint exposure was considered., Conclusion: The dorsal intermetatarsal approach appeared to be feasible for access to the lateral collateral ligament and the lateral half of the plantar plate. The average joint exposure of 6 mm allowed a quality suture passage by a suture passer in both structures in all specimens without the need of a metatarsal osteotomy., Clinical Relevance: This operative approach may be appropriate for early stages plantar plate tear when only lateral soft tissue repair is needed. This technique should not preclude conversion to a more extensile operative approach or an additional metatarsal osteotomy if needed. Applicability of this operative approach in cases with more advanced pathologies or involving only medial soft tissue structures requires further studies.

Background: The open modified Broström anatomic repair technique is widely accepted as the reference standard for lateral ankle stabilization. Despite recent increases in publications regarding arthroscopic repair of the anterior talofibular ligament (ATFL) for treatment of chronic ankle instability, research is lacking that compares the functional outcomes between arthroscopic repair and open repair procedures for chronic ankle instability., Purpose: To compare function and activity level after arthroscopic repair versus open repair of the ATFL in patients with lateral ankle instability., Study Design: Cohort study; Level of evidence, 3., Methods: All patients who underwent arthroscopic or open surgical Broström repair of the ATFL between January 2012 and August 2014 were invited to participate in this study. All of the patients had consented for arthroscopic repair if feasible. In cases in which arthroscopic repair was impossible, the open modified Broström procedure was performed after arthroscopy. Patients accepted a systematic rehabilitation program postoperatively. American Orthopaedic Foot and Ankle Society (AOFAS) score, Karlsson Ankle Functional Score (KAFS), and Tegner activity score were used to evaluate ankle function preoperatively and at a minimum follow-up of 2 years. Magnetic resonance imaging (MRI) was performed to evaluate the signal to noise ratio (SNR) of the repaired ATFL., Results: A total of 60 patients were included in this study. They were assigned to 1 of 2 groups according to their surgical procedure: 23 patients underwent arthroscopic repair (arthroscopic group) and 37 patients underwent open repair (open group). No patient in either group had ankle instability at follow-up postoperatively. After surgery, the AOFAS score ( P < .001), KAFS ( P < .001), and Tegner activity score ( P < .001) increased significantly in both groups. However, no significant difference was found in AOFAS score (93.3 ± 8.9 vs 92.4 ± 8.6; P = .7), KAFS (90.3 ± 12.5 vs 89.4 ± 10.6; P = .75), and Tegner score (5 ± 2 vs 5 ± 2; P = .61) between the arthroscopic group and the open group, respectively. As well, no significant difference was found in the mean SNR value of ATFL between the arthroscopic group and the open group (9.1 ± 2.7 vs 8.8 ± 2.3; P = .39, respectively)., Conclusion: When compared with open lateral ankle repair, arthroscopic repair of lateral ankle ligament when feasible produced similarly favorable outcomes. Arthroscopic ATFL repair, as a minimally invasive technique, provided favorable outcomes.

Aim: To determine whether the anterior talofibular ligament injury will influence the Hook test result., Method: A three-dimensional model of the ankle was established based on CT scan of a healthy volunteer and ligament attachment through references; Four groups (A-D) of operating conditions were set up. In group A, the anterior and posterior ligaments of the inferior tibiofibular joint were cut off and the anterior talofibular ligament was kept intact; in group B, all the anterior and posterior tibiofibular ligaments and the anterior talofibular ligament were cut off; in group C, the medial and lateral ligaments of the ankle joint and the inferior tibiofibular ligament were kept intact; in group D, only the talofibular ligament was cut off and other ligaments were kept intact. The proximal end of the model was restrained in all four groups, an outward pulling force of 100N perpendicular to the fibula was applied, and displacement and rotation of the distal end of the fibula in the four groups was observed., Results: When the inferior tibiofibular joint injury was associated with an anterior talofibular ligament injury, the Hook test indicated about 3.19mm of displacement of the distal end of the fibula, and obvious external rotation occurred due to increased activity of the anterior border of the fibula. In the other groups, a single inferior tibiofibular joint injury or a single anterior talofibular ligament injury did not increase displacement or rotation of the distal end of the fibula., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Studies regarding magnetic resonance imaging (MRI) findings of the lateral ankle ligaments in chronic lateral ankle instability and their clinical relevance for surgery are lacking. This study classified the lateral ankle ligament MRI findings of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) in chronic lateral ankle instability (CLAI) and correlated these findings with ankle stress radiographs., Methods: We included 132 ankles with CLAI that underwent ligament reconstructions from 2006 to 2013. The distributions of the ATFL and CFL morphologies were evaluated using the following categories: (1) the amount of thickness: normal/thickened/attenuated/non-visualized, (2) the presence of discontinuity, (3) wavy or irregular contour, and (4) increased signal intensity on T2-weighted images. The relationships between the ligament morphologies and stress radiographs were analyzed., Results: The ATFL was normal in 5 (4%) ankles, thickened in 35 (27%), attenuated in 76 (58%), and non-visualized in 16 (12%), while the CFL was normal in 39 (30%) ankles, thickened in 42 (32%), attenuated in 44 (33%), and non-visualized in 7 (5%). Discontinuity of the ATFL or CFL was observed in 46 (35%) ankles. Wavy or irregular contours were observed in 55 (42%) ATFLs and 37 (28%) CFLs, and signal intensity of both ligaments was increased in 19 (14%) ankles. ATFL ( P < .001) and CFL thickness ( P = .007) correlated with the talar tilt angle., Conclusions: The MRI findings of CLAI showed several morphologies and specific incidences for each morphology. Attenuated, wavy appearance was the most frequent MRI pattern. Thickness was related to the degree of instability., Level of Evidence: Level IV, retrospective case series.

Objective: To assess the prevalence of injury of the talonavicular ligament (TNL) in ankle sprains, its anatomy and the stability of the talonavicular joint (TNJ) before and after dividing the TNL in a cadaver., Methods: During a prospective study of 100 patients to assess the outcome of ankle injuries, we noted high incidence of TNL injuries; we will discuss here the TNL findings. Each patient had undergone ultrasound and cone beam CT examination of the ankle. Six TNLs were dissected off fresh-frozen cadaveric feet for histological analysis. In further six cadaveric feet, the stability of the TNJ was assessed by mechanical stress before and after division of the TNL; movement at the joint was assessed by measuring the distance between the talus and navicular bone [talonavicular distance (TD)] using ultrasound. The TD was measured on ten randomly selected ultrasound images by three independent observers and repeated twice by a single observer to determine the inter- and intraobserver reliability., Results: 21% of the patients had an injury to the TNL. Histological examination demonstrated a dense connective tissue composed of bundles of collagen in parallel arrangement along the ligament length. The interobserver and intraobserver reliability of the TD showed almost perfect agreement. Displacement at the TNJ after stress with the TNL intact measured 0.18 ± 0.08 cm and 0.29 ± 0.07 cm (p < 0.005) when divided., Conclusion: The TNL is surprisingly commonly injured in ankle sprains. Its anatomy and histology suggest a role in tensile force transmission during the windlass mechanism in gait. Advances in knowledge: Injury to the TNL is common and has not been described. Its anatomy suggests resistance to tensile forces and its injury allows excessive movement at the TNJ.

Background: The function of the anterolateral capsule of the knee has not been clearly defined. However, the contribution of this region of the capsule to knee stability in comparison with other anterolateral structures can be determined by the relative force that each structure carries during loading of the knee. Purpose/Hypothesis: The purpose of this study was to determine the forces in the anterolateral structures of the intact and anterior cruciate ligament (ACL)-deficient knee in response to an anterior tibial load and internal tibial torque. It was hypothesized that the anterolateral capsule would not function like a traditional ligament (ie, transmitting forces only along its longitudinal axis)., Study Design: Controlled laboratory study., Methods: Loads (134-N anterior tibial load and 7-N·m internal tibial torque) were applied continuously during flexion to 7 fresh-frozen cadaveric knees in the intact and ACL-deficient state using a robotic testing system. The lateral collateral ligament (LCL) and the anterolateral capsule were separated from the surrounding tissue and from each other. This was done by performing 3 vertical incisions: lateral to the LCL, medial to the LCL, and lateral to the Gerdy tubercle. Attachments of the LCL and anterolateral capsule were detached from the underlying tissue (ie, meniscus), leaving the insertions and origins intact. The force distribution in the anterolateral capsule, ACL, and LCL was then determined at 30°, 60°, and 90° of knee flexion using the principle of superposition., Results: In the intact knee, the force in the ACL in response to an anterior tibial load was greater than that in the other structures ( P < .001). However, in response to an internal tibial torque, no significant differences were found between the ACL, LCL, and forces transmitted between each region of the anterolateral capsule after capsule separation. The anterolateral capsule experienced smaller forces (~50% less) compared with the other structures ( P = .048). For the ACL-deficient knee in response to an anterior tibial load, the force transmitted between each region of the anterolateral capsule was 434% greater than was the force in the anterolateral capsule ( P < .001) and 54% greater than the force in the LCL ( P = .036) at 30° of flexion. In response to an internal tibial torque at 30°, 60°, or 90° of knee flexion, no significant differences were found between the force transmitted between each region of the anterolateral capsule and the LCL. The force in the anterolateral capsule was significantly smaller than that in the other structures at all knee flexion angles for both loading conditions ( P = .004 for anterior tibial load and P = .04 for internal tibial torque)., Conclusion: The anterolateral capsule carries negligible forces in the longitudinal direction, and the forces transmitted between regions of the capsule were similar to the forces carried by the other structures at the knee, suggesting that it does not function as a traditional ligament. Thus, the anterolateral capsule should be considered a sheet of tissue., Clinical Relevance: Surgical repair techniques for the anterolateral capsule should restore the ability of the tissue to transmit forces between adjacent regions of the capsule rather than along its longitudinal axis.

Background: Subtalar instability is associated with up to 80% of patients presenting with chronic ankle instability but is often not considered in the diagnosis or treatment. Operative procedures to repair ankle instability have shown good clinical results, but the effects of these reconstruction procedures on isolated subtalar instability are not well understood. The goal of this study was to investigate the effect of the Gould modification of the Broström procedure and a new tenodesis reconstruction procedure on ankle and subtalar joint kinematics after simulating a subtalar injury., Methods: Kinematic data were collected on 7 cadaveric ankles during inversion through the range of ankle flexion and during internal rotation. Testing was performed on the intact foot; after sectioning the calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament; after the Gould modification of the Broström procedure was performed; and after tenodesis was performed and sutures from the Gould modification removed., Results: The Gould modification of the Broström procedure significantly decreased subtalar and ankle inversion motion and subtalar internal rotation compared to the unstable condition. The tenodesis method restricted internal rotation at the subtalar joint and ankle inversion compared to the intact state., Conclusion: Both operative procedures improved stability of the ankle complex, but tenodesis was unable to restore subtalar inversion and restricted ankle inversion in maximum plantarflexion., Clinical Relevance: The Gould modification of Broström ligament repair may be a favorable operative procedure for the restoration of subtalar and ankle joint kinematics.

Background: The anterior half of the peroneus longus tendon (AHPLT) has been reported to be an effective autograft for ligament reconstruction with respect to strength and safety. However, there is little information regarding donor site morbidity after harvesting the AHPLT. Furthermore, to the best of our knowledge, there has not been a study on the isokinetic evaluation of ankle plantar flexion and eversion after AHPLT harvesting., Purpose: To evaluate the clinical and radiographic results after lateral ankle ligament reconstruction using the AHPLT. We further investigated whether harvesting the AHPLT for lateral ankle ligament reconstruction decreases the strength of ankle plantar flexion and eversion., Study Design: Case series; Level of evidence, 4., Methods: Thirty consecutive patients (31 cases) were treated by anatomic lateral ligament reconstruction using the AHPLT. For the clinical assessment, visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS), and Karlsson-Peterson scores were evaluated preoperatively and at the last follow-up. For the radiographic assessment, talar tilt angle and anterior talar displacement were measured preoperatively and at the last follow-up. The peak isokinetic torques for ankle plantar flexion at angular velocities of 30 and 120 deg/s and eversion at angular velocities of 30 and 60 deg/s were measured at a minimum of 1 year after surgery., Results: The mean VAS score improved significantly from 6.4 ± 1.7 preoperatively to 1.6 ± 1.5 at the last follow-up ( P < .001). The mean respective AOFAS and Karlsson-Peterson scores improved significantly from 57.2 ± 12.8 and 66.9 ± 13.6 preoperatively to 89.0 ± 10.0 and 93.3 ± 5.7 at the last follow-up ( P < .001). The mean talar tilt angle improved significantly from 15.3° ± 6.2° preoperatively to 3.4° ± 3.0° at the last follow-up ( P < .001), and the mean anterior talar displacement improved significantly from 10.2 ± 3.3 mm preoperatively to 6.3 ± 1.9 mm at the last follow-up ( P < .001). No significant differences were observed between the uninvolved and involved legs in the mean peak torque for plantar flexion at angular speeds of 30 deg/s ( P = .517) and 120 deg/s ( P = .347) or for eversion at angular speeds of 30 deg/s ( P = .913) and 60 deg/s ( P = .983)., Conclusion: Anatomic lateral ligament reconstruction using the AHPLT showed good clinical and radiographic results without a significant decrease in the peroneus longus strength. Lateral ligament reconstruction using the AHPLT may be a good surgical option for the treatment of chronic ankle instability.

Chronic ankle instability is a disabling condition, often occurring as a result of traumatic ankle injury. A paucity of published data is available documenting chronic ankle instability in the pediatric population. Much of the data has been confined to the adult population. We present 2 cases of chronic ankle instability, 1 in a 12-year-old and 1 in a 9-year-old patient. Unlike the typical adult etiology, the cause of instability was a dysfunctional lateral ligamentous complex as a consequence of bony avulsion of the tip of the fibula. Both patients had sustained a twisting injury to the ankle. The fractures failed to unite. The nonunion resulted in dysfunction of the anterior talofibular ligament with consequent chronic ankle instability. At the initial clinical assessment, magnetic resonance imaging was requested for both patients. In patient 1 (12 years old), the fracture was fixed with 2 headless screws and was immobilized in a plaster cast for 6 weeks. In patient 2 (9 years old), because of the small size of the avulsed fragment, fixation was not possible. A modified Gould-Broström procedure was undertaken, facilitating repair of the avulsed fragment using anchor sutures., (Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The role of the anterolateral capsule (ALC) as a secondary restraint to quantitative rotatory laxity of patients with an anterior cruciate ligament (ACL) injury is currently debated., Purpose/hypothesis: The purpose was to determine the influence of concomitant ALC injuries as well as injuries to other soft tissue structures on rotatory knee laxity in patients with an ACL injury. It was hypothesized that a concomitant ALC injury would be associated with increased rotatory knee laxity as measured during a quantitative pivot-shift test., Study Design: Cross-sectional study; Level of evidence, 3., Methods: Forty-one patients with an ACL injury (average age, 23 ± 6.9 years) were enrolled. Two blinded musculoskeletal radiologists reviewed magnetic resonance imaging (MRI) scans for the presence of ACL injuries and concomitant soft tissue injuries including the ALC, medial collateral ligament, lateral collateral ligament, posterolateral corner, medial meniscus, and lateral meniscus. A standardized pivot-shift test was performed under anesthesia, and rotatory laxity was quantified according to anterior translation of the lateral tibial compartment during the pivot-shift maneuver. The Student t test was used to analyze the data. Statistical significance was set at P < .05., Results: A complete ACL rupture was confirmed in all of the patients. MRI evidence of an ALC injury was observed in 21 (51%) of the patients. Patients with MRI evidence of an ALC injury had significantly higher rotatory knee laxity (3.6 ± 1.5 mm) compared with those without an ALC injury (2.7 ± 1.5 mm; P = .04). Lateral and medial meniscus injuries were detected in 17 (41%) and 19 (46%) patients, respectively. Patients with MRI evidence of either a medial meniscus injury or lateral meniscus injury had significantly higher rotatory knee laxity compared with patients without these injuries (medial meniscus: 3.7 ± 1.4 mm vs 2.7 ± 1.6 mm, respectively; lateral meniscus: 3.7 ± 1.7 mm vs 2.7 ± 1.3 mm, respectively) (P = .03 for both)., Conclusion: MRI evidence of a concomitant injury to the ALC, medial meniscus, or lateral meniscus is associated with increased knee rotatory laxity in patients with an ACL injury. These structures may function as important secondary stabilizers in an ACL-injured knee. Careful assessment and proper treatment of injuries to these secondary stabilizers should be considered, especially in knees with a high level of the pivot shift., (© 2016 The Author(s).)

Context: The mechanisms that contribute to the development of chronic ankle instability are not understood. Investigators have developed a hypothetical model in which neuromuscular alterations that stem from damaged ankle ligaments are thought to affect periarticular and proximal muscle activity. However, the retrospective nature of these studies does not allow a causal link to be established., Objective: To assess temporal alterations in the activity of 2 periarticular muscles of the rat ankle and 2 proximal muscles of the rat hind limb after an ankle sprain., Design: Controlled laboratory study., Setting: Laboratory., Patients or Other Participants: Five healthy adult male Long Evans rats (age = 16 weeks, mass = 400.0 ± 13.5 g)., Intervention(s): Indwelling fine-wire electromyography (EMG) electrodes were implanted surgically into the biceps femoris, medial gastrocnemius, vastus lateralis, and tibialis anterior muscles of the rats. We recorded baseline EMG measurements while the rats walked on a motor-driven treadmill and then induced a closed lateral ankle sprain by overextending the lateral ankle ligaments. After ankle sprain, the rats were placed on the treadmill every 24 hours for 7 days, and we recorded postsprain EMG data., Main Outcome Measure(s): Onset time of muscle activity, phase duration, sample entropy, and minimal detectable change (MDC) were assessed and compared with baseline using 2-tailed dependent t tests., Results: Compared with baseline, delayed onset time of muscle activity was exhibited in the biceps femoris (baseline = -16.7 ± 54.0 milliseconds [ms]) on day 0 (5.2 ± 64.1 ms; t 4 = -4.655, P = .043) and tibialis anterior (baseline = 307.0 ± 64.2 ms) muscles on day 3 (362.5 ± 55.9 ms; t 4 = -5.427, P = .03) and day 6 (357.3 ± 39.6 ms; t 4 = -3.802, P = .02). Longer phase durations were observed for the vastus lateralis (baseline = 321.9 ± 92.6 ms) on day 3 (401.3 ± 101.2 ms; t 3 = -4.001, P = .03), day 4 (404.1 ± 93.0 ms; t 3 = -3.320, P = .048), and day 5 (364.6 ± 105.2 ms; t 3 = -3.963, P = .03) and for the tibialis anterior (baseline = 103.9 ± 16.4 ms) on day 4 (154.9 ± 7.8 ms; t 3 = -4.331, P = .050) and day 6 (141.9 ± 16.2 ms; t 3 = -3.441, P = .03). After sprain, greater sample entropy was found for the vastus lateralis (baseline = 0.7 ± 0.3) on day 6 (0.9 ± 0.4; t 4 = -3.481, P = .03) and day 7 (0.9 ± 0.3; t 4 = -2.637, P = .050) and for the tibialis anterior (baseline = 0.6 ± 0.4) on day 4 (0.9 ± 0.5; t 4 = -3.224, P = .03). The MDC analysis revealed increased sample entropy values for the vastus lateralis and tibialis anterior., Conclusions: Manually inducing an ankle sprain in a rat by overextending the lateral ankle ligaments altered the complexity of muscle-activation patterns, and the alterations exceeded the MDC of the baseline data.

Background: The aim of this prospective study was to evaluate the influence of sectioning the calcaneofibular ligament (CFL) during an extensile lateral approach during open reduction and internal fixation (ORIF) of calcaneal fractures on ankle joint stability., Methods: Forty-two patients with calcaneal fractures that received ORIF were included. Talar tilt stress and anterior drawer radiographs were performed on the operative and contralateral ankles 6 months postoperatively., Results: The average degree of talar tilt on stress radiographs was 3.4 degrees (range, 0-12 degrees) on the operative side and 3.2 degrees (range, 0-14 degrees) on the contralateral side. The mean anterior drawer on stress radiographs of the CFL incised ankle was 6.1 mm (range, 2.4-11.8 mm) and on the contralateral ankle was 5.7 mm (range, 2.6-8.6 mm). There was no statistically significant difference of talar tilt and anterior drawer between the CFL incised side and the contralateral side (P = .658 and .302, respectively)., Conclusion: The results suggest that sectioning of the CFL without any repair during ORIF of a calcaneal fracture does not have a negative effect on stability of the ankle. Repair of the CFL is, thus, probably not necessary following extended lateral approach for ORIF of calcaneal fractures., Level of Evidence: Level II, comparative study., (© The Author(s) 2016.)

Introduction: If a syndesmosis injury is not detected, or not treated appropriately, it can lead to pain and arthritis. Various techniques have been described to look for the presence of a syndemosis injury. If concern is raised regarding malreduction, the most recognised way of checking accuracy of the reduction (of the fibula into the incisura) is bilateral postoperative ankle CT scans. This not only exposes the patient to further radiation, but can normally only be done once the surgery is completed and so if adjustment is needed, this requires a further operation, encompassing further surgical risks. We developed a simple assessment, which both gives accurate intra-operative demonstration of an injury to the syndesmosis and also can check how well the fibula has been reduced (if required), without the need for further radiological investigation or surgical intervention. The objectives were to test how easy it was to perform the test and apply it to a number of different ankle fractures., Methods: Peri-operatively, 2-4ml of contrast medium was injected into the ankle joint in cases where there was concern about injury to the syndesmosis. If there was a 'positive' test, and a 'blush' of dye leaked into the surrounding soft tissues, then fixation of the syndesmosis was performed (as per the surgeon's preferred technique). After fixation was completed, a further injection of contrast medium was injected to see if the fibular had been anatomically reduced into its incisura. The test was performed on 15 ankles., Results: There were no difficulties in performing the test and no complications reported. The test clearly demonstrated where there had been an injury to the syndesmosis and also confirmed the accurate reduction of the fibula when there had been stabilisation of the syndesmosis., Conclusions: It has proved to be an easy and reliable adjunct to ankle fixation surgery and may have further indications., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Distinguishing between ankle instability and subtalar joint instability is challenging because the contributions of the subtalar joint's soft-tissue constraints are poorly understood. This study quantified the effects on joint stability of systematic sectioning of these constraints followed by application of torsional and drawer loads simulating a manual clinical examination., Methods: Subtalar joint motion in response to carefully controlled inversion, eversion, internal rotation, and external rotation moments and multidirectional drawer forces was quantified in fresh-frozen cadaver limbs. Sequential measurements were obtained under axial load approximating a non-weight-bearing clinical setting with the foot in neutral, 10° of dorsiflexion, and 10° and 20° of plantar flexion. The contributions of the components of the inferior extensor retinaculum were documented after incremental sectioning. The calcaneofibular, cervical, and interosseous talocalcaneal ligaments were then sectioned sequentially, in two different orders, to produce five different ligament-insufficiency scenarios., Results: Incremental detachment of the components of the inferior extensor retinaculum had no effect on subtalar motion independent of foot position. Regardless of the subsequent ligament-sectioning order, significant motion increases relative to the intact condition occurred only after transection of the calcaneofibular ligament. Sectioning of this ligament produced increased inversion and external rotation, which was most evident with the foot dorsiflexed., Conclusions: Calcaneofibular ligament disruption results in increases in subtalar inversion and external rotation that might be detectable during a manual examination. Insufficiency of other subtalar joint constraints may result in motion increases that are too subtle to be perceptible., Clinical Relevance: If calcaneofibular ligament insufficiency is established, its reconstruction or repair should receive priority over that of other ankle or subtalar periarticular soft-tissue structures., (Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.)

Purpose: Lateral ankle sprains are common and can manifest into chronic ankle instability (CAI) resulting in altered gait mechanics that may lead to subsequent ankle sprains. Our purpose was to simultaneously analyse muscle activation patterns and plantar pressure distribution during walking in young adults with and without CAI., Methods: Seventeen CAI and 17 healthy subjects walked on a treadmill at 4.8 km/h. Plantar pressure measures (pressure-time integral, peak pressure, time to peak pressure, contact area, contact time) of the entire foot and nine specific foot regions and medial-lateral location of centre of pressure (COP) were measured. Surface electromyography (EMG) root mean square (RMS) amplitudes throughout the entire stride cycle and area under RMS curve for 100 ms pre-initial contact (IC) and 200 ms post-IC for anterior tibialis, peroneus longus, medial gastrocnemius, and gluteus medius were collected., Results: The CAI group demonstrated a more lateral COP throughout the stance phase (P < 0.001 and Cohen's d > 0.9 for all 10 comparisons) and significantly increased peak pressure (P = 0.025) and pressure-time integral (P = 0.049) under the lateral forefoot. The CAI group had lower anterior tibialis RMS areas (P < 0.001) and significantly higher peroneus longus, medial gastrocnemius, and gluteus medius RMS areas during 100 ms pre-IC (P < 0.003). The CAI group had higher gluteus medius sEMG amplitudes during the final 50 % of stance and first 25% of swing (P < 0.05)., Conclusions: The CAI group had large lateral deviations of their COP location throughout the entire stance phase and increased gluteus medius muscle activation amplitude during late stance through early swing phase., Level of Evidence: III.