Background: The utility of forefoot cleaning using bristled brush has been proposed by previous studies but has not been tested in any study. The aim of the current study is to investigate the antiseptic efficacy of additional forefoot scrubbing with bristled brush after a standard 2-step preparation with alcohol and chlorhexidine in foot and ankle surgery. Methods: One hundred patients underwent foot and ankle surgery by one orthopedic surgeon were included and categorized into one of two groups of different skin preparation procedure before surgery. Group 1 is the control group which received a standard 2-step preparation with alcohol and chlorhexidine. Group 2 is the forefoot scrubbing group which received a standard preparation with alcohol and chlorhexidine and an additional forefoot scrubbing in a sterile fashion. Positive culture results and microbe species were primary outcomes. A secondary outcome was the occurrence of any surgical site infection (SSI) 12 months following surgery. Results: The hallux nail fold positive rate of the forefoot scrubbing group was significantly lower than that of the control group after draping (forefoot scrubbing group, 0 %; control group, 12 %; p = 0.027) and after surgery (forefoot scrubbing group, 6 %; control group, 28 %; p = 0.003). The microbe species of hallux nail fold after surgery included Staphylococcus, coagulase negative, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Neisseria, and Corynebacterium afermentans. There was no difference in the rate of SSI between the forefoot scrubbing group (10 %) and the control group (6 %). Conclusion: Forefoot scrubbing with bristled brush before foot and ankle surgery reduces microbe growth rate after draping and after surgery at hallux nail fold. Level of evidence: Level II, prospective cohort study. (c) 2024 European Foot and Ankle Society. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

BACKGROUND:In patients with lateral ankle instability (LAI) and attenuated ligament tissue quality, the stability of lateral ankle can be achieved through percutaneous inferior extensor retinaculum augmentation (PIERA). This study is aimed to compare the functional outcomes of PIERA with gold standard Modified Broström Procedure (MBP) for patients with LAI. METHODS:Twenty participants were allocated to PIERA and MBP treatment group according to the intraoperative arthroscopic assessment of lateral ankle ligament, with each group comprises 10 participants. Patients were assessed using American Orthopaedic Foot and Ankle Society score, Cumberland ankle instability tool, Foot and Ankle Ability Measure, star excursion balance test (SEBT), and a stair descent gait analysis, a day prior to surgery and one year postoperatively. Operative outcomes and variables during stair descent were documented and compared between the preoperative and postoperative patients, and between treatment groups. RESULTS:The PIERA procedure significantly promoted the clinical outcomes of the patients with LAI. The anterior reach of SEBT was increased from 79.1 ± 12.6 to 84.8 ± 12.9 (p = 0.034). The PIERA procedure significantly increased ankle flexion range of motion (p = 0.049), maximal ankle dorsiflexion (p = 0.009), and peroneal activation post-initial-contact (p = 0.002) and during the gait cycle (p = 0.015). The effects of PIERA and MBP on ankle function were not significantly different. CONCLUSION:PIERA produces similar functional outcomes compared with MBP in promoting clinical outcomes, dynamic postural stability, peroneal activation, and ankle sagittal range of motion for patients with LAI. LEVEL OF EVIDENCE:III, retrospective cohort study.

Context Individuals with mechanical ankle instability (MAI) have obvious lateral ligament laxity and excessive ankle joint motion beyond the physiological range. Arthrometry has been introduced to quantitatively measure the laxity of the ankle joint. However, the diagnostic accuracy of arthrometry in MAI is still debatable. Objectives To (1) evaluate the difference in laxity between bilateral ankles in patients with and those without MAI and (2) calculate the diagnostic accuracy of ankle arthrometry using bilateral comparisons. Design Cross-sectional study. Setting Research laboratory. Patients or Other Participants A total of 38 individuals with unilateral MAI (age = 31.24 ± 7.90 years, height = 168.93 ± 7.69 cm, mass = 65.72 ± 10.47 kg) and 38 individuals without MAI (control group; age = 32.10 ± 7.10 years, height = 166.59 ± 7.89 cm, mass = 62.93 ± 10.72 kg). Main Outcome Measure(s) Bilateral ankle laxity in each participant was quantitatively measured by performing the arthrometric anterior drawer test. Continuous data of loading force and joint displacement were recorded. Data from both ankles were compared for the ankle joint displacement at a loading force of 75 N (D75) and load-displacement ratio from 10 to 40 N (LDR 10–40). Results The D75 between injured and uninjured ankles in patients with MAI was different (t37 = 9.78, P < .001). The mean LDR 10–40 in injured ankles was higher than that in uninjured ankles (t37 = 9.80, P < .001). In the control group, no differences were found between the left and right ankles. The MAI group had larger bilateral differences than the control group (t37 range = 7.33–8.18; P < .001). When LDR 10–40 was used to diagnose MAI, the arthrometer showed sensitivity and specificity of 0.900 and 0.933, respectively, with a cutoff value of 0.0351 mm/N. Conclusions An ankle arthrometer can be used to quantitatively measure the difference in bilateral ankle laxity in patients with MAI. Arthrometer-measured LDR 10–40 can be used to diagnose MAI with high diagnostic accuracy.

Background Subtalar arthroereisis (STA) has gained growing acceptance as a viable approach solution for the management of pediatric flexible flatfoot. However, STA still remains controversial. The purpose of this study is to assess the effect of STA using the Talar-Fit implant for treating pediatric flexible flatfoot. Specifically, the aims of the study are as follows: first, to present the mid-term outcomes of STA using the Talar-Fit implant; second, to compare the radiographic and clinical outcomes associated with varying sizes of Talar-Fit implant; and third, to analyze the optimal position of the inserted implants. Methods A retrospective analysis was conducted on a cohort of 57 pediatric patients diagnosed with flexible flatfoot (77 feet) who underwent STA utilizing Talar-Fit between January 2014 and December 2021. The participants were categorized into five groups according to the size of the implant: Group 8, Group 9, Group 10, Group 11, and Group 12. The evaluation included the assessment of clinical function using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle–hind foot score, as well as the assessment of radiographic data such as the calcaneal pitch angle (CPA), lateral Meary angle (LMA), talar declination angle (TDA), and medial longitudinal arch angle (MLAA) were evaluated. Furthermore, the position of the inserted implants was also recorded, including angle, depth, and distance. The comparison of pre- and postoperation was conducted using the paired Student's t -test, whereas the analysis of differences among subgroups was performed using the Wilcoxon rank-sum test. A P -value < 0.05 is considered statistically significant. Results In total, 57 pediatric patients (77 feet) were successfully followed-up for an average period of 26.8 months. The overall AOFAS score significantly improved from 58.6 ± 10.9 to 85.2 ± 8.6 ( P < 0.001). Furthermore, the LMA decreased from 20.3° ± 3.6° to 4.5° ± 1.3°, the CPA increased from 14.8° ± 1.6° to 23.6° ± 2.7°( P < 0.05), the TDA decreased from 40.2° ± 2.3° to 25.5° ± 3.2°( P < 0.05), and the MLAA decreased from 140.1° ± 2.8° to 121.4° ± 3.9°( P < 0.05). No statistically significant differences were observed among subgroups regarding the final outcomes. The improvements of CPA, TDA, and MLAA among different groups were significantly different; however, the adjusted P -values were all greater than 0.05. The implant were inserted at a mean angle of 89.5° ± 2.4°, a mean depth of 0.9 mm ± 2.1 mm, and a mean distance of 9.9 mm ± 0.9 mm. Eight patients experienced complications, including six cases of pain occurrence and two cases of implant dislocation. Conclusion STA with Talar-Fit has demonstrated satisfactory mid-term outcomes. A Talar-Fit with a larger size may demonstrate a superior effect when compared with that of a smaller size. The implants were inserted in a similar position, indicating that the medial edge of the implant may be possible to transcend the midline of the talus neck.

Supplemental Digital Content is Available in the Text. Objectives:To determine the diagnostic accuracy of various stress tests for deltoid ligament and syndesmosis injury in patients with ankle fracture.Data Sources:A systemic literature search was conducted in the MEDLINE, Embase, and Cochrane Library databases to identify studies published from January 1990 to August 2022.Study Selection:Studies that evaluated external rotation or gravity stress tests or hook or tap tests for the diagnosis of deltoid ligament or syndesmosis injury were included.Data Extraction:Authors, publication years, study design, index tests, reference standards, demographic features of participants, reliability, and the numbers of true-positive, true-negative, false-positive, and false-negative subjects were extracted from 14 included studies. Article quality was assessed through the revised Quality Assessment of Diagnostic Accuracy Studies tool.Data Synthesis:The pooled sensitivity and specificity of each index test for each structure were calculated with a random-effects model using the extracted data of true-positive, true-negative, false-positive, and false-negative outcomes in all relevant studies. The overall diagnostic performance of the different index tests for different structures was determined with the estimation of the area under the curve using the summary receiver operating characteristics curve.Conclusions:The gravity stress test and the tap test exhibited high sensitivity and specificity in diagnosing deltoid ligament injury. The hook test has relatively high accuracy in diagnosing syndesmosis injury. Further studies with large sample sizes are warranted to confirm the results of this review.Level of Evidence:Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Although Dimeglio and Pirani scores are frequently employed to rate the severities of clubfoot and to evaluate treatment outcomes, it is unclear if these scores predict relapse after treatment. Ankle dorsiflexion has been suggested in recent years to be a promising predictor of relapse. The aim of this study was to investigate ankle dorsiflexion and Dimeglio and Pirani scores in predicting the relapse of clubfoot after treatment with the Ponseti method. We included patients with clubfoot previously treated by the Ponseti method, and retrospectively analyzed their initial ankle dorsiflexion, Pirani and Dimeglio scores, number of castings, and the occurrence of relapse. We analyzed 218 feet of 176 infants with clubfoot who showed an incidence of relapse of 17.0% (30/176). The mean initial Pirani and Dimeglio scores of the feet showing recurrence were significantly higher than individuals with non-recurrence (p < .001 each). We observed a robust association between Pirani and Dimeglio scores and the recurrence of clubfoot at the last follow-up (γ = 0.53, p = .001). In contrast, ankle dorsiflexion was negatively correlated with recurrence of clubfoot (γ = -0.21, p = .001). Dimeglio scores significantly predicted the recurrence of clubfoot (p = .014). Receiver operating characteristic curve analysis exhibited slightly better performance regarding the Dimeglio score relative to the Pirani score and ankle dorsiflexion in predicting recurrence. Ankle dorsiflexion and Pirani and Dimeglio scores were related to recurrence in patients with clubfoot. However, the Dimeglio score reflected superior accuracy in predicting the prognosis of clubfoot treated with the Ponseti method.

Background:Fitting the surface morphology of the talar trochlea is one of the common methods to define the geometric axis of the tibiotalar joint (GATJ). However, the in vivo motion of such axis during gait has not been fully investigated.Methods:The ankle kinematic data of fifteen volunteers were collected by a dual fluoroscopic imaging system with a model-image registration method. The GATJ was defined by sphere-fitting the medial or lateral part of the trochlear surface of the talus. The position and orientation of this axis during gait were measured. To verify this axis, the distances of the feature points of the talus to the GATJ during gait were also measured.Results:There was no statistically significant difference in the distances of feature points of the talus to the GATJ among the seven key poses of the gait cycle. And the position and orientation of the GATJ during gait also showed no statistically significant difference.Conclusion:The GATJ is the axis about which the talus rotated. And it is one fixed axis during gait. The current finding may help the design of the talar component for total ankle replacement based on the surface morphology of the talar trochlea.

Background Different treatment methods have been developed for acute Achilles tendon rupture (ATR), including conservative treatment, minimally invasive or transdermal surgery, and open surgery, and there is no consensus about which method is superior. It is important to clarify the presence of Achilles tendon (AT) degeneration, the rupture site, and the rupture shape before surgery to determine whether minimally invasive or open surgery should be selected, thereby reducing the re‐rupture rate following acute ATR. The aim of this study was to investigate the diagnostic value of MRI in identifying the presence of AT degeneration, the rupture site, and the rupture shape for acute closed ATR. Methods From January 2016 to December 2019, patients with acute closed ATR who had undergone repair surgery were retrospectively enrolled. All patients received MRI examination, and the distance between the insertion site and broken end and the rupture shape (types I, II, and III) were independently determined by two observers. Then, the stump of the AT was exposed during the operation. The rupture site and rupture shape were recorded and compared and analyzed with the MRI results. Consistency analyses (using Cohen's kappa coefficient or intraclass correlation coefficient‐ICC) and calculation of diagnostic performance indexes were, respectively, conducted to evaluate the diagnostic value of the MRI. Results This study included 47 consecutive patients with acute ATR, with an average age of 38.4 years. Among them, 40 were male, and seven were female. The intraoperative exploration demonstrated a total of 34 (72.3%), 10 (21.3%), and three (6.4%) patients with type I, II, and III ruptures, respectively. The average distance between the insertion site and the proximal broken end measured intraoperatively was 4.07 ± 1.57 cm. High or excellent consistencies were found for ATR classifications (kappa: 0.739–0.770, p < 0.001) and rupture sites (ICC: 0.962–0.979, p < 0.001) between two observers and between observers 1 and 2 and intraoperative findings. Tendinopathy was identified in 22 patients by MRI and confirmed during surgery. Conclusions MRI scanning of acute closed ATR can help determine whether there is degeneration of the AT, as well as the location and shape of the rupture, which can guide the selection of the optimal operation method for orthopedic surgeons. Therefore, it is necessary to take preoperative MRI scans for patients with acute Achilles tendon ruptures.

Background: This study aims to assess the mechanical and functional effects of the arthroscopic modified Brostrom procedure (AMBP) on patients with lateral ankle instability.Methods: Eight patients with unilateral ankle instability treated with AMBP and eight healthy subjects were recruited. Healthy subjects, preoperative and one-year postoperative patients were assessed using outcome scales and the Star Excursion Balance Test (SEBT) for dynamic postural control. One-dimensional statistical parametric mapping was performed to compare ankle angle and muscle activation curve during stair descent.Results: The patients with lateral ankle instability showed good clinical outcomes and increased posterior lateral reach during the SEBT after the AMBP (p = 0.046). The medial gastrocnemius activation after initial contact was reduced (p = 0.049), and the peroneal longus activation after initial contact was promoted (p = 0.014).Conclusion: The AMBP has functional effects of promoting dynamic postural control and peroneal longus activation within one year of follow-up, which can benefit patients with functional ankle instability. However, the medial gastrocnemius activation was unexpectedly reduced post operation.(c) 2023 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Background. Peripheral neuropathy is regarded as one of the leading causes of fatal and nonfatal falls. Wearable sensors, due to their increasing availability and flexibility of setting and space, are used widely to obtain wearer’s kinematic data to analyze one’s balance capacities for the evaluation of risk of fall. There is yet to have a review study focusing on the application of wearable sensors in the scope of fall risk for patients with peripheral neuropathy. Objective. To investigate the methods by which researchers adopt to assess risk of fall in peripheral neuropathy patients and potentially shed light on future researches. Methods. A systematic review design was used to identify articles on fall risk assessment and balance training using wearable sensors in patients with peripheral neuropathy. The study is aimed at extracting the following information: the type of sensors, the type of signal and data processing employed, the scales and tests used in the study, and the type of application. Results. We identified 351 studies, from which 8 were included. An average sample size of 35.6 patients enrolled the studies. The accelerometer was the most common wearable sensor used. 10-meter walk test was the preferable procedure for assessing risk of fall. Conclusion. This review examined several key components in studies on assessing and improving the risk of fall using wearable sensors. We identified the preferred functional test (10-meter walk test), sensor technology (accelerometer), locations (torso and lower legs), and fall risk improvement methods (prostheses). However, due to the limited number of articles specializing in this field of research, a consensus on patient sample size and procedures is not reached. We would recommend future researches to examine more parameters and adopt a fusion sensor setup.

Multiple synostoses syndromes (SYNS) are a group of rare genetic bone disorders characterized by multiple joint fusions. We previously reported an SYNS4‐causing GDF6 c.1330 T > A (p.Tyr444Asn) mutation, which reduced Noggin‐induced GDF6 inhibition and enhanced SMAD1/5/8 signaling. However, the mechanisms by which GDF6 gain‐of‐function mutation alters joint formation and the comprehensive molecular portraits of SYNS4 remain unclear. Herein, we introduce the p.Tyr443Asn (orthologous to the human GDF6 p.Tyr444Asn) mutation into the mouse Gdf6 locus and report the results of extensive phenotype analysis, joint development investigation, and transcriptome profiling of Gdf6 p.Tyr443Asn limb buds. Gdf6 p.Tyr443Asn knock‐in mice recapitulated the morphological features of human SYNS4, showing joint fusion in the wrists, ankles, phalanges, and auditory ossicles. Analysis of mouse embryonic forelimbs demonstrated joint interzone formation defects and excess chondrogenesis in Gdf6 p.Tyr443Asn knock‐in mice. Further, RNA sequencing of forelimb buds revealed enhanced bone formation and upregulated bone morphogenetic protein (BMP) signaling in mice carrying the Gdf6 p.Tyr443Asn mutation. Because tightly regulated BMP signaling is critical for skeletal development and joint morphogenesis, our study shows that enhancing GDF6 activity has a significant impact on both prenatal joint development and postnatal joint maintenance. © 2023 American Society for Bone and Mineral Research (ASBMR).

Objective:To investigate the short-term effectiveness of calcaneal lateral displacement osteotomy with lateral ligament repair in the treatment of Takakura stage Ⅱ varus-type ankle arthritis.Methods:A retrospective analysis was performed on the clinical data of 13 patients with Takakura stage Ⅱ varus-type ankle arthritis treated with calcaneal lateral displacement osteotomy with lateral ligament repair between January 2016 and December 2020. There were 6 males and 7 females aged 31-65 years, with an average age of 53.6 years. The preoperative tibial-ankle surface angle (TASA) was (88.13±1.01)°, medial distal tibial angle (MDTA) was (86.36±1.49)°, tibial talar surface angle (TTSA) was (6.03±1.63)°, talar tilting angle (TTA) was (81.95±2.15)°, and tibiocalcaneal axis angle (TCAA) was (-5.74±6.81)°. The preoperative American Orthopedic Foot and Ankle Society (AOFAS) score was 56.3±7.1 and the pain visual analogue scale (VAS) score was 3.7±0.5. AOFAS scores, VAS scores, TTSA, TTA, and TCAA were compared between pre- and post-operatively.Results:All 13 patients were followed up 14-41 months, with an average of 28.7 months. The osteotomies healed in all patients. The last follow-up revealed TTA, TTSA, and TCAA to be (88.27±1.19)°, (-0.13±1.37)°, and (2.09±5.10)° respectively, the AOFAS score was 84.3±4.2 and the VAS score was 0.7±0.5, all showing significant improvement when compared to preoperative values ( P<0.05).Conclusion:For patients with Takakura stage Ⅱ varus-type ankle arthritis, calcaneal lateral displacement osteotomy with lateral ligament repair can correct the lower limb force line, regain ankle stability, and achieving good short-term effectiveness.

Abstract Background Arthrometry has been introduced to evaluate the laxity of ankle joint in recent years. However, its role in the diagnosis of chronic ankle instability is still debatable. Therefore, we assessed the diagnostic accuracy of a digital arthrometer in terms of sensitivity and specificity. Methods According to the inclusion and exclusion criteria proposed by the International Ankle Consortium, we recruited 160 uninjured ankles (control group) and 153 ankles with chronic ankle instability (CAI group). Ankle laxity was quantitively measured by a validated digital arthrometer. Data of loading force and joint displacement were recorded in a continuous manner. Differences between the control and CAI groups were compared using 2-tailed independent t test. A receiver operating characteristic curve analysis was used to calculate area under a curve, sensitivity and specificity. Results Load–displacement curves of the two groups were depicted. Differences of joint displacement between the control and CAI groups were compared at 30, 45, 60, 75, 90, 105 and 120 N, which were all of statistical significance (all p < 0.001) with the largest effect size at 90 N. Statistical significance was found in the differences between the two groups in load–displacement ratio at 10–120 N, 10–40 N, 40–80 N and 80–120 N (all p < 0.001), with the largest effect size at 10–40 N. Load–displacement ratio at the interval of 10–40 N had the highest area under a curve (0.9226), with sensitivity and specificity of 0.804 and 0.863, respectively, when the cutoff point was 0.1582 mm/N. Conclusion The digital arthrometer measurement could quantitively analyze the ankle laxity with high diagnostic accuracy. The load–displacement ratio would be a reliable and promising approach for chronic ankle instability diagnosis. Level of evidence level II.

Background This study is aimed at exploring the prognostic value of preoperative lymphocyte-to-monocyte ratio (LMR), an index of systemic inflammation before operation, in ankle lateral ligament repair (ALLR). Methods A total of 213 I-III degrees injuries of lateral ankle ligament patients received ALLR and were followed up for more than 2 years. Univariate and multivariable linear regression analysis was used to determine the relationship between preoperative LMR and postoperative recovery. The evaluations of postoperative recovery include American Orthopaedic Foot and Ankle Society (AOFAS) score, Karlsson-Peter ankle score (KPAS), Cumberland Ankle Instability Tool (CAIT) score, Visual Analog Scale (VAS) score, and range of motion (ROM). The prognostic value of preoperative LMR was measured by receiver operating characteristic (ROC) curve. Results 178 patients (178 ankles) were followed up successfully, with a follow-up of 2.82 ± 1.54 years. Overall, the mean AOFAS, KPAS, CAIT and VAS scores, and ankle varus angle were significantly improved at the final follow-up. Univariate and multiple linear regression analysis showed that preoperative LMR was the only independent factor associated with postoperative function, ROM, and pain. The preoperative LMR of patients with poor recovery was significantly lower than that of patients with good recovery. Based on the ROC analysis, the cutoff value of preoperative LMR was 3.824. The clinical outcomes of patients with preoperative LMR < 3.824 were significantly lower than that of patients with preoperative LMR ≥ 3.824. The corresponding specificity and sensitivity were 84.6% and 71.4%. Conclusion The clinical outcomes of open or arthroscopic repair for ATFL injury are satisfactory. As a marker of systemic inflammation, preoperative LMR can be used as a prognostic indicator for ALLR.

Abstract Objective To specify indications and contraindications of the modified percutaneous inferior extensor retinaculum augmentation (PIERA) technique for chronic ankle instability cases, and to introduce technique details and report surgical outcomes and complications. Methods The PIERA technique was performed on seven patients with chronic ankle instability (four females and three males, 36.4 ± 15.1 years of age, and course of symptoms of 33.7 ± 8.8 months) from June to October 2018 in this retrospective study of case series. All patients demonstrated attenuated ligamentous tissue quality, which was confirmed using preoperative ankle MRI. IER were drew up to the distal fibula using suture anchors with the ankle in neutral position for all cases, to engage the entire IER in reconstructing the stability of the ankle. Patients were assessed using American Orthopaedic Foot and Ankle Society Ankle‐Hindfoot (AOFAS) score and Cumberland Ankle Instability Tool (CAIT) scores pre‐ and postoperatively at the last follow‐up examination. Preoperative and postoperative outcome scores of patients were compared using paired t‐test. A p value of less than 0.05 was regarded statistically significant. Results Mean follow‐up duration was 16.7 ± 1.6 months. The mean AOFAS score significantly improved from 66.9 ± 11.2 preoperatively to 93.7 ± 8.5 postoperatively (P = 0.001). Mean CAIT score significantly improved from 13.1 ± 4.7 preoperatively to 26.3 ± 1.8 postoperatively (P = 0.001). Patients did not report any wound healing problem, numbness, swelling, or instability at the last follow‐up examination, except for one patient who reported pain and minimal stiffness, and presented an AOFAS score of less than 80 and a CAIT score below 24. All patients returned to at least recreational sport activity level. Conclusion The PIERA technique can improve the functional outcomes of patients with chronic ankle instability with few complications.

BACKGROUND:The anterior and posterior part of the deltoid ligament have different functions during ankle flexion motion. Partial ligament injuries have been demonstrated in previous clinical reports. However, the efficacy of external rotation stress test in partial injured cases is unavailable till now.METHODS:Thirty-two fresh cadaveric specimens were included and allocated into two destabilization groups. In the first group, the anterior portion of deltoid ligament (DL) and syndesmotic ligament were sequentially severed, while in the second group, the posterior portion of DL and syndesmotic ligament were sequentially severed. Mortise view radiographs were taken after each destabilization stage when the ankles were placed at plantarflexion and dorsiflexion positions and stressed in standard external rotation force. The medial clear space (MCS) and talar tilt (TT) angle were measured and compared among different destabilization stages.RESULTS:When the ankles were placed at neutral position, the TT significantly increased in all destabilization stages. The MCS significantly increased after the partial deltoid ligament ruptures only with presence of syndesmotic ligament injuries. There was no significant difference of MCS at plantarflexion for all stages of destabilization if the anterior portion of DL is preserved. Similarly, no significant increase of MCS was detected at dorsiflexion if the posterior portion of DL and posterior inferior tibiofibular ligament are intact.CONCLUSION:Partial DL rupture causes ankle rotational instability at different ankle joint positions, especially when combined with syndesmotic injuries. The neutral position is recommended for diagnosis of partial DL ruptures under external rotation stress.

A biomechanical study, in which imaging modalities are used to strictly include patients with concurrent lateral ankle instability (LAI) and osteochondral lesions of the talus (OLT), is needed to demonstrate the static and dynamic ankle range of motion (ROM) restriction in these patients, and determine whether ankle ROM restriction can be corrected postoperatively. Eight patients with concurrent LAI and OLT treated with the arthroscopic modified Broström procedure and microfracture were recruited from June 2019 to January 2020. Patients were assessed using outcome scales, static ankle ROM, and a stair descent gait analysis for dynamic ankle ROM, a day prior to surgery and one year postoperatively. Eight healthy subjects were assessed using the same modalities upon recruitment. Operative outcomes and variables during stair descent were documented and compared among the preoperative, postoperative, and healthy groups. A curve analysis, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalised time series. The functional outcomes of patients with concurrent LAI and OLT were significantly worse than those of healthy subjects preoperatively, but were partially improved postoperatively. Patients had decreased static and dynamic ROM preoperatively, and static ROM did not significantly increase postoperatively (preoperative, 39.6 ± 11.3; postoperative, 44.9 ± 7.1; healthy, 52.0 ± 4.6; p = 0.021). Patients showed increased dynamic ankle flexion ROM (preoperative, 41.2 ± 11.6; postoperative, 53.6 ± 9.0; healthy, 53.9 ± 3.4; p = 0.012) postoperatively, as well as increased peroneus longus activation (preoperative, 35.8 ± 12.0; postoperative, 55.4 ± 25.1; healthy, 71.9 ± 13.4; p = 0.002) and muscle co-contraction of the tibialis anterior and peroneus longus (preoperative, 69.4 ± 23.4; postoperative, 88.4 ± 9.3; healthy, 66.2 ± 18.1; p = 0.045). Patients with concurrent LAI and OLT had decreased static and dynamic sagittal ankle ROM and altered neuromuscular activation patterns. The arthroscopic modified Broström procedure and microfracture did not significantly increase the static sagittal ankle ROM. However, the dynamic sagittal ankle ROM, peroneus longus activation and muscle co-contraction of the tibialis anterior and peroneus longus increased postoperatively. IV.

Aims: : Therapeutic footwear with variable-stiffness properties has been shown to be effective in reducing the external knee adduction moment. However, the exact changes of internal tissue stresses following intervention with variable-stiffness footwear remains unknown. The objective of this study is to construct a finite element model of the foot-ankle-knee complex to investigate the therapeutic efficacy of the variable-stiffness footwear in modulating internal knee joint stress distributions.Methods: : Footwear with lateral-to-medial stiffness ratio of 1.00, 1.33, 1.49 and 1.77 were designed and 3D printed as lattice structures at different porosity levels. A three-dimensional finite element model of the foot ankle-knee complex was constructed with cartilage-meniscus structures characterized by magnetic resonance imaging. Ground reaction forces and muscular loads estimated from gait experiments with 3D-printed variable stiffness footwear were used to drive the model, and effects of footwear intervention with four stiffness ratios on tibiofemoral joint loads were evaluated during the simulated instant in gait.Results: : Compared with the constant-stiffness design, the variable-stiffness footwear reached a maximum reduction of the first peak knee adduction moment up to 17.1%. As the lateral-to-medial stiffness ratio increases, the peak stresses at the meniscus in the medial compartment of the knee were reduced by 5.0%, 7.9%, and 16.4%, respectively. The stress-modifying effects were less pronounced for the lateral compartment of the knee.Conclusion: : The variable-stiffness footwear design produced stress relieving to the cartilage and meniscus structures, and the fact that lower stiffness ratio had reached significantly less effects, suggesting a favourable stress-relief effect should consider footwear with a higher lateral-to-medial stiffness ratio.

BACKGROUND:Length change pattern of the ankle deltoid ligament during physiological ankle motion is still confused currently and had not been studied in vivo. METHODS:The deltoid ligaments from 7 cadaveric specimens were dissected. Lengths of each band during 30° plantarflexion to 20° dorsiflexion were measured. A dual fluoroscopy imaging system was utilized to capture the images of hindfoot joint of 7 healthy subjects during the stance phase of walking. 3D bone models were reconstructed from CT images. Lengths of each band were calculated after model-image registration utilizing a solid modeling software. Percentage of length variation and poses when the bands were in maximum extension were documented among each band. RESULTS:The anterior border of tibiocalcaneal ligament (TCL) had only 1.7% length variation in vitro and 5.7% length variation in vivo. The tibionavicular ligament, tibiospring ligament, and deep anterior tibiotalar ligament were in maximum extension at 30° plantarflexion, however, superficial posterior tibiotalar ligament, deep posterior tibiotalar ligament, and the posterior border of TCL were in maximum extension at 20° dorsiflexion. The tibionavicular ligament, tibiospring ligament, and deep anterior tibiotalar ligament were in maximum extension during foot flat. The TCL was in maximum extension during midstance. The superficial posterior tibiotalar ligament and deep posterior tibiotalar ligament were in maximum extension during heel off and toe off. CONCLUSION:The length of TCL did not change during ankle dorsiflexion and plantarflexion. The bands anterior to and posterior to the TCL showed different length change pattern during physiological ankle dorsiflexion and plantarflexion.

Background: Previous studies on the kinematics of patients with chronic ankle instability (CAI) that did not incorporate MRI and arthroscopic assessment could not differentiate between patients with CAI without osteochondral lesion of the talus (OLT) and patients with CAI and OLT and have thus presented contradictory results. Research question: This study aimed to investigate the kinematic and electromyographic differences between patients with and without OLT. Methods: Sixteen subjects with CAI (eight without OLT and eight with OLT confirmed through MRI and arthroscopic assessment) and eight healthy subjects underwent gait analysis in a stair descent setting. The three groups' patient-reported outcomes; ankle joint range of motion in flexion, inversion and rotation; and muscle activation of the peroneus, tibialis anterior, and gastrocnemius during a gait cycle were analyzed and compared. A curve analysis, namely, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalized time series. Results: The patients with and without OLT had no difference in patient-reported outcomes. The maximal ankle plantarflexion of the patients without OLT and the healthy subjects was significantly larger than that of patients with OLT (p = 0.005). The maximal ankle internal rotation of patients without OLT was significantly larger than that of patients with OLT (p = 0.048). The peroneal activation during 0-6% of the gait cycle of patients with OLT was reduced compared with the healthy subjects. Significance: Patients with CAI and OLT and patients with CAI without OLT have no difference in patient-reported outcomes, but patients with OLT can be differentiated using the post-initial-contact peroneal activation deficit and the restriction of ankle plantarflexion and internal rotation during stair descent. These variables can be utilized to monitor the function of patients with CAI and their possibility of developing OLT.