Evaluation of thickness and appearance of anterior talofibular and calcaneofibular ligaments in normal versus abnormal ankles with MRI

Broström ankle ligament repair augmented with suture tape : Results of magnetic resonance imaging evaluation

BACKGROUND

The Broström procedure is an established procedure in cases of primary lateral ankle ligament repair (LALR). To improve postoperative stability an augmentation device, InternalBrace™ (Arthrex, Naples, FL) has been introduced. This study evaluates remodelling of the anterior talofibular ligament (ATFL) in patients undergoing a tape augmented Broström technique as well as clinical outcomes.

METHODS

In this study 32 patients with chronic lateral ankle instability (CLAI) receiving augmented LALR were included. Clinical outcomes were evaluated at a one-time postoperative visit between 12 and 18 months. A 3 T magnetic resonance imaging (MRI) was done to evaluate the morphology of the ATFL. Statistical analysis was completed with the free software and environment R version 3.6.3 (Bell Laboratories, Murray Hill, NJ, USA) and P-values < 0.05 were considered statistically significant.

RESULTS

The mean follow-up time was 15.3 ± 1.8 months with a return to sport time of 4.0 ± 2.4 months. The average AOFAS (American Orthopaedic Foot and Ankle Society Score) score was 94.4 ± 7.2, the FAOS (Foot and Ankle Outcome Score) demonstrated 87.3 ± 10.4 points and the FFI (Foot Function Index - 2 scores (pain and function score)) was 22.9 ± 20.1 and 15.4 ± 10.4, respectively. The MRI findings demonstrated an average length of the ATFL of 18.6 ± 4.3 mm and the width was 3.6 ± 0.9 mm. A clear differentiation between the ATFL and the augmentation device could be shown in 28 cases. The Fisher's exact test could not depict a significant correlation between the presence of a bone marrow edema and the tension of the augmentation device with a level of significance of α = 0.05.

CONCLUSION

An anatomical healing tendency of the ligament repair and good integrity of the augmentation device could be shown based on MRI findings. The lateral ligament repair augmented with suture tape is an effective and safe procedure regarding surgical treatment in chronic lateral ankle instability producing good clinical outcome.

Investigation into the effect of deltoid ligament injury on rotational ankle instability using a three-dimensional ankle finite element model

Background

Injury to the lateral collateral ligament of the ankle may cause ankle instability and, when combined with deltoid ligament (DL) injury, may lead to a more complex situation known as rotational ankle instability (RAI). It is unclear how DL rupture interferes with the mechanical function of an ankle joint with RAI.

Purpose

To study the influence of DL injury on the biomechanical function of the ankle joint.

Methods

A comprehensive finite element model of an ankle joint, incorporating detailed ligaments, was developed from MRI scans of an adult female. A range of ligament injury scenarios were simulated in the ankle joint model, which was then subjected to a static standing load of 300 N and a 1.5 Nm internal and external rotation torque. The analysis focused on comparing the distribution and peak values of von Mises stress in the articular cartilages of both the tibia and talus and measuring the talus rotation angle and contact area of the talocrural joint.

Results

The dimensions and location of insertion points of ligaments in the finite element ankle model were adopted from previous anatomical research and dissection studies. The anterior drawer distance in the finite element model was within 6.5% of the anatomical range, and the talus tilt angle was within 3% of anatomical results. During static standing, a combined rupture of the anterior talofibular ligament (ATFL) and anterior tibiotalar ligament (ATTL) generates new stress concentrations on the talus cartilage, which markedly increases the joint contact area and stress on the cartilage. During static standing with external rotation, the anterior talofibular ligament and anterior tibiotalar ligament ruptured the ankle's rotational angle by 21.8% compared to an intact joint. In contrast, static standing with internal rotation led to a similar increase in stress and a nearly 2.5 times increase in the talus rotational angle.

Conclusion

Injury to the DL altered the stress distribution in the tibiotalar joint and increased the talus rotation angle when subjected to a rotational torque, which may increase the risk of RAI. When treating RAI, it is essential to address not only multi-band DL injuries but also single-band deep DL injuries, especially those affecting the ATTL.

Postoperative Magnetic Resonance Evaluation of Anterior Talofibular Ligament Following Arthroscopic Brostrom Procedure: Analysis and Outcomes of 40 Repairs at 12 Months

Lateral ankle sprains are one of the most common orthopedic injuries. When conservative treatment fails, surgical correction is often performed using either open or arthroscopic techniques. We hypothesize that MRI evaluation of the arthroscopic brostrom repair will show intact repair and decrease in thickness of the anterior talofibular ligament (ATFL) at 1 year, with statistically significant improvement of patient function and pain scores. Postoperative MRI was utilized at minimum 1-year follow-up to evaluate the integrity of the arthroscopic brostrom repair, as well as comparison of ATFL thickness to literature validated average thickness. A musculoskeletal fellowship trained radiologist performed all MRI reads. In addition, 3 fellowship trained foot and ankle specialists from a single institution all performed measurements of the ATFL. Surgical satisfaction using 1 to 100 scale, and Karlsson-Peterson (KP) were measured at 1 year postoperatively. In addition, pre- and postoperative Foot Function Index (FFI), American Orthopedic Foot and Ankle (AOFAS) hindfoot scores, and Visual Analog Scale (VAS) were measured using unpaired t tests. All repairs were shown to be intact at minimum 1-year follow-up via MRI evaluation, with ATFL thickness of 2.21 mm. Preoperative FFI, AOFAS, and VAS were 54.9, 46.4, and 7.1 respectively. Postoperative scores were 11.0, 91.7, and 1.3 respectively. Surgical satisfaction was 88.2, KP was 75.3. Comparison of pre- and postoperative scores (VAS, FFI, AOFAS) were shown to be statistically significant, p < .05. No significant difference in demographic data was observed at 1 year. The data from this study offers evidence that the arthroscopic brostrom repair provides patients with good outcomes as well as an intact ATFL with normal morphology at 1 year postoperatively.

Advanced Imaging in the Chronic Lateral Ankle Instability: An Algorithmic Approach

Imaging examinations are a fundamental part of assessing chronic lateral ankle instability (CLAI). Plain radiographs are used in the initial examination, whereas stress radiographs can be requested to actively search for instability. Ultrasonography (US) and Magnetic Resonance Imaging (MRI) allow direct visualization of ligamentous structures, with the advantage of dynamic evaluation for US, and assessment of associated lesions and intra-articular abnormalities for MRI, which plays an essential role in surgical planning. This article reviews imaging methods to diagnose and follow up on CLAI, along with illustrative cases and an algorithmic approach.

The effect of thickness and elastic modulus of the anterior talofibular ligament on anterior ankle joint stiffness: A subject-specific finite element study

Ankle sprain is a frequent type of sports injury leading to lateral ligament injury. The anterior talofibular ligament (ATFL) is a primary ligamentous stabilizer of the ankle joint and typically the most vulnerable ligament injured in a lateral ankle sprain (LAS). This study aimed to quantitively investigate the effect of the thickness and elastic modulus of ATFL on anterior ankle joint stiffness (AAJS) by developing nine subject-specific finite element (FE) models under acute injury, chronic injury, and control conditions of ATFL. A 120 N forward force was applied at the posterior calcaneus leading to an anterior translation of the calcaneus and talus to simulate the anterior drawer test (ADT). In the results, the ratio of the forward force to the talar displacement was used to assess the AAJS, which increased by 5.85% in the acute group and decreased by 19.78% in the chronic group, compared to those of the control group. An empirical equation described the relationship between AAJS, thickness, and elastic modulus (R-square 0.98). The equation proposed in this study provided an approach to quantify AAJS and revealed the effect of the thickness and the elastic modulus of ATFL on ankle stability, which may shed light on the potential diagnosis of lateral ligament injury.

Imaging of Acute Ankle and Foot Sprains

Ankle and foot injuries are very common injuries in the general population, and more so in athletes. MR imaging is the optimal modality to evaluate for ligamentous injuries of the ankle and associated conditions after ankle sprain. In this article, the authors discuss the epidemiology, biomechanics, normal anatomy, and pathology of the ankle as well as injuries of the hindfoot and midfoot that are often associated with ankle injuries.

Magnetic resonance imaging of the ankle: Pathology of the lateral and posterior compartments

Magnetic resonance imaging (MRI) is the gold standard for imaging the tendons and the ligaments of the ankle. MRI combines excellent tissue contrast and accurate anatomic delineation of joint structures. In the first article of this series, we discussed a compartmental approach to the interpretation of ankle pathology focusing on the anterior and medial compartments. This article will complete the MR review of the ankle, with a focus on the lateral and posterior compartments of the ankle.

Platelet-rich plasma, a biomaterial, for the treatment of anterior talofibular ligament in lateral ankle sprain

Background: Because of the rising prevalence of anterior talofibular ligament (ATFL) damage, there is a considerable interest in developing innovative techniques to improve the biological healing response of ATFL. Platelet-rich plasma (PRP) includes several growth factors linked to a favorable healing response, however none of the studies involved both quality evaluation and clinical results to evaluate this treatment. Purpose: To determine the clinical results of PRP injections into the ATFL in lateral ankle sprain (LAS) patients, as well as the quality of the ATFL based on radiographic outcomes. Methods: Patients with clinically confirmed grade II LAS for the first time (n = 83) were examined. The clinical outcomes of three types of injection methods were evaluated: none, once within 48 h after the sprain, and once more 4 weeks later after first injection. PRP was injected into the tear site of the ATFL using ultrasound guidance, and all ankles were immobilized for 2 weeks. The American Orthopedic Foot and Ankle Score (AOFAS) ankle-hindfoot scale and the Visual Analogue Scale (VAS) were used to assess the results at 2, 6, 8, 24, and 48 weeks of follow-up. The signal/noise ratio (SNR) value of Magnetic Resonance Imaging (MRI)-based ATFL signal intensity can disclose ATFL quality. The ATFL SNR results were then assessed 8, 24 and 48 weeks following the first injection to compare ATFL quality. Results: The PRP injection groups outperformed the control group in terms of clinical outcomes, and the two injections group outperformed other groups in terms of pain reduction and functional outcome at 8 weeks. The clinical results of all groups were comparable at 6 and 12 months follow-up. ATFL SNR findings improved significantly across all groups over time. At the same follow-up time, the PRP injection groups outperformed the control group, and the best SNR result showed in the two injections group at the final follow-up. Conclusion: PRP injection helped relieve early symptoms of LAS, although all patients saw a similar development after 6 months. The two PRP injections group produced considerably better clinical results and quality of the ATFL in short-term follow-up.

The anterior talofibular ligament: A thin-slice three-dimensional magnetic resonance imaging study

PURPOSE

The aim of this study was to provide an accurate and improved understanding of anterior talofibular ligament (ATFL) anatomy, and to determine the exact positioning and diameter of the bony tunnel during ATFL repair and/or reconstruction surgery.

METHOD

A total of 58 healthy asymptomatic volunteers were examined, wherein 38 underwent bilateral ankle 3D MRI, and 20 underwent unilateral ankle 3D MRI (10 left and 10 right ankles). Data from a total of 96 MRI datasets were collected. The MRI data from these cases were exported into Mimics to enable reconstruction of 3D ATFL models. The resulting image quality was evaluated using a 5-point subjective scoring system. In addition, the length, width, thickness, and positioning of each ATFL and the area of the ATFL footprints were identified within the 3D model using Mimics and SolidWorks.

RESULTS

The image quality score was 4.48 ± 0.50. The ATFL formed one (65.6%), two (31.3%), or three (3.1%) bundles forms. The footprint area was 31.25 ± 6.29 mm² on the fibular side, and 17.48 ± 4.49 mm² on the talar side.

CONCLUSION

Thin-slice 3D MRI aids in the reconstruction of the 3D ATFL model, and it provides reference for the accurate anatomy of the area and location of the ATFL. This technology will facilitate diagnosis of ATFL injuries and choice of surgical methods.

LEVEL OF EVIDENCE

level IV.

The Influence of Suture-Tape Augmentation on Biological Healing of the Anterior Talofibular Ligament in Chronic Ankle Instability: A Quantitative Analysis Using MRI

While the effectiveness of suture-tape augmentation for chronic ankle instability has been supported biomechanically and clinically, little information is available regarding biological changes of the lateral ligaments postoperatively. This study aims to quantitatively evaluate ligament regeneration with MRI after suture-tape augmentation. Forty-six patients underwent MRI scan at follow-up of a minimum of 1 year after lateral ligaments augmentation using suture-tape. The signal-to-noise ratio (SNR) and width of anterior talofibular ligament (ATFL) were measured on preoperative and postoperative MRI by 3 researchers. The degree of biological healing of ATFL was analyzed based on the change of SNR and comparison with normal contralateral ankle. Clinical outcomes were evaluated with the Foot and Ankle Outcome Score, Foot and Ankle Ability Measure. Mean Foot and Ankle Outcome Score and Foot and Ankle Ability Measure scores improved significantly from 63.1 to 92.7, and 59.6 to 91.5 points at final follow-up, respectively (p < .001). Mean SNR and width of ATFL were changed insignificantly from 8.24 to 7.96, and 1.88 mm to 2.05 mm at final follow-up, respectively (p = .391, .509). As compared to contralateral side, there were significant differences in both mean SNR and width of the ATFL, respectively (p < .001, p = .0012). Spearman's correlation analysis revealed no significant association between clinical outcomes and degree of biological healing of ATFL based on MRI. Despite significant improvement in patient-reported clinical outcomes, the influence on ligament regeneration of suture-tape augmentation for chronic ankle instability was insignificant. In addition, there was no significant correlation between clinical outcomes and degree of biological healing of the ATFL.

Morphologic evaluation of injured and contralateral uninjured ankles in patients with unilateral chronic ankle instability

OBJECTIVE

To compare the morphological anatomy and abnormalities of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) in unilateral chronic ankle instability (CAI).

METHODS

22 patients (men: women, 13:9; mean age, 28.95 ± 8.127 years) with unilateral CAI and 18 healthy volunteers (men: women, 9:9, mean age, 28.33 ± 3.678 years) were recruited. MRI scans were divided into Group 1 (22 injured ankles), Group 2 (22 contralateral uninjured ankles), and Group 3 (36 healthy volunteer ankles). The morphologic variables, MRI signal intensity (SI) values were evaluated.

RESULTS

The ATFL proximal, intermediate, and distal sites and the CFL proximal and distal sites in Group 3 were narrower than those in Group 1 (P ＜0.05). Both ATFL and CFL in Group 1 were thicker than those in Group 3 (P ＜0.01). The proximal and intermediate sites of the ATFL and the proximal site of the CFL in Group 3 were narrower than those in Group 2 (P ＜0.01). The intermediate site of the ATFL and the proximal and distal sites of the CFL in Group 2 were thicker than those in Group 3 (P ＜0.01). The mean SI values of the ATFL in Group 1 were higher than those in Groups 2 and 3 (P ＜0.01). The ATFL and CFL SI values were higher in Group 2 than those in Group 3 (P ＜0.05).

CONCLUSION

Both the injured and contralateral uninjured ankles had wider ATFL and CFL, more thickness, and higher SI values compared with those of healthy volunteer ankles.

ADVANCES IN KNOWLEDGE

High-resolution three-dimensional MRI provides a potential tool assisting clinical decision on the treatment and rehabilitation therapy of patients with unilateral CAI.

Diagnostic Performance of Ultrasonography for Evaluation of Osteoarthritis of Ankle Joint: Comparison With Radiography, Cone-Beam CT, and Symptoms

OBJECTIVES

To determine the diagnostic performance of ultrasonography (US) for evaluation of the ankle joint osteoarthritic (OA) changes. Cone-beam computed tomography (CT) was used as the gold standard and US performance was compared with conventional radiography (CR). As a secondary aim, associations between the imaging findings and ankle symptoms were assessed.

METHODS

US was performed to 51 patients with ankle OA. Every patient had prior ankle CR and underwent cone-beam CT during the same day as US examination. On US, effusion/synovitis, osteophytes, talar cartilage damage, and tenosynovitis were evaluated. Comparison to respective imaging findings on CR and cone-beam CT was then performed. Single radiologist blinded to other modalities assessed all the imaging studies. Symptoms questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), was available for 48 patients.

RESULTS

US detected effusion/synovitis of the talocrural joint with 45% sensitivity and 90% specificity. For the detection of anterior talocrural osteophytes, US sensitivity was 78% and specificity 79%. For the medial talocrural osteophytes, they were 39 and 83%, and for the lateral talocrural osteophytes 54 and 100%, respectively. Considering cartilage damage of the talus, US yielded a low sensitivity of 18% and high specificity of 97%. Overall, the performance of US was only moderate and comparable to CR. The imaging findings showed only weak associations with ankle symptoms.

CONCLUSIONS

The ability of US to detect ankle OA is only moderate. Interestingly, performance of CR also remained moderate. The associations between imaging findings and WOMAC score seem to be weak in ankle OA.

Morphometric relationships between dimensions the anterior talofibular ligament and calcaneofibular ligament in routine magnetic resonance imaging

Purpose

This study aimed to test the hypothesis that routine MRI ankle can be used to evaluate dimensions and correlations between dimensions of single and double fascicular variants of the ATFL and the CFL.

Methods

We reviewed ankle MRIs for 251 patients. Differences between the length, thickness, width, and length of the bony attachments were evaluated twice. P < .05 was considered as significant.

Results

For the ATFL, we observed a negative correlation between thickness and width, with a positive correlation between thickness and length (p < 0.001). The average values for the ATFL were thickness, 2.2 ± 0.05 mm; length, 21.5 ± 0.5 mm; and width, 7.6 ± 0.6 mm. The average values for the CFL were thickness, 2.1 ± 0.04 mm; length, 27.5 ± 0.5 mm; and width, 5.6 ± 0.3 mm. A negative correlation was found between length and width for the CFL (p < 0.001).

Conclusions

Routine MRI showed that most dimensions of the ATFL and CFL correlate with each other, which should be considered when planning new reconstruction techniques and developing a virtual biomechanical model of the human foot.

Level of evidence

III

The signal intensity of preoperative magnetic resonance imaging has predictive value for determining the arthroscopic reparability of the anterior talofibular ligament

PURPOSE

Arthroscopic all-inside anterior talofibular ligament (ATFL) repair is a common surgical technique for chronic ankle instability (CAI), and the condition of the ATFL remnants is associated with its reparability. ATFL reparability can affect the clinical course, but the relationship between magnetic resonance imaging (MRI) findings and the intraoperative ATFL reparability is still unclear. The purpose of this study was to investigate the relationship between ATFL signal intensities according to MRI and intraoperative ATFL reparability.

METHODS

This study included 55 cases of CAI (n = 37) and osteochondral lesion of the talus (n = 18) that underwent MRI followed by subsequent arthroscopy. MRI signal intensity was measured preoperatively to calculate the signal to noise ratio (SNR). During arthroscopy, the presence of an ATFL tear was checked and the ATFL tension was classified as taut, mild laxity, or laxity; ATFL quality was classified as excellent (normal), moderate (abnormal but reparable), or poor (irreparable). It was then analyzed whether there was a relationship between the intraoperative findings and the SNR.

RESULTS

The mean SNR was 23.4 ± 21.6. The SNR was significantly different according to the presence of an ATFL tear and ATFL tension and quality (all P = 0.001). The SNR was better correlated with ATFL quality (r = 0.708) than the presence of a tear (r = 0.545) or degree of tension (r = 0.653). The diagnostic SNR cutoff point to distinguish a normal ATFL from an abnormal but reparable ATFL was 11.2, and that to distinguish between an irreparable and reparable ATFL, was 32.3.

CONCLUSION

The SNR, representing MRI signal intensities, is highly correlated with the intraoperative measures of the ATFL. Therefore, the SNR had predictive value for determining the arthroscopic reparability of the ATFL.

LEVEL OF EVIDENCE

Level III.

Evaluation of ankle ligaments with CT: A feasibility study

PURPOSE

This study aims to systematically investigate if normal ankle ligaments can be assessed with CT imaging, using MRI as reference standard.

METHODS

35 patients (mean age: 47 ± 15 years; female n = 19) with combined CT and MRI exams and without MR-morphologic signs of ankle ligamental injury were retrospectively identified. 3 readers independently evaluated the syndesmotic, the lateral and medial ankle ligaments in terms of visibility on a 4-point Likert scale (0-3 points) in multiplanar MDCT images in standard bone kernel reconstructions. In consensus CT-based ligament density and thickness were measured and the appearance was rated for each ligament. Results were compared and validated with corresponding MRI images.

RESULTS

Almost all ankle ligaments identified in MRI images could be adequately depicted in standard multiplanar bone kernel CT images with a mean visual score of 2.7/3 (± 0.2). Difficulties in CT morphological delineation of ankle ligaments occurred in cases of filiform TNL and TCL and in cases of concurrent soft tissue edema. Interreader agreement for the CT-assessment of ankle ligaments was excellent, with Fleiss Kappa values >0.8. Mean density of evaluated medial and lateral ankle ligaments was 68 ± 2.9 HU, with substantially inter- and intraindividual variations. Thickness measurements and assessment of appearance of ankle ligaments showed a good concordance between CT and MRI.

CONCLUSIONS

Assessment of normal ankle ligaments via standard CT in bone kernel reconstructions is feasible, with some restrictions concerning the medial collateral ligaments and in the presence of soft tissue edema.

The double fascicular variations of the anterior talofibular ligament and the calcaneofibular ligament correlate with interconnections between lateral ankle structures revealed on magnetic resonance imaging

The anterior talofibular ligament and the calcaneofibular ligament are the most commonly injured ankle ligaments. This study aimed to investigate if the double fascicular anterior talofibular ligament and the calcaneofibular ligament are associated with the presence of interconnections between those two ligaments and connections with non-ligamentous structures. A retrospective re-evaluation of 198 magnetic resonance imaging examinations of the ankle joint was conducted. The correlation between the double fascicular anterior talofibular ligament and calcaneofibular ligament and connections with the superior peroneal retinaculum, the peroneal tendon sheath, the tibiofibular ligaments, and the inferior extensor retinaculum was studied. The relationships between the anterior talofibular ligament's and the calcaneofibular ligament's diameters with the presence of connections were investigated. Most of the connections were visible in a group of double fascicular ligaments. Most often, one was between the anterior talofibular ligament and calcaneofibular ligament (74.7%). Statistically significant differences between groups of single and double fascicular ligaments were visible in groups of connections between the anterior talofibular ligament and the peroneal tendon sheath (p < 0.001) as well as the calcaneofibular ligament and the posterior tibiofibular ligament (p < 0.05), superior peroneal retinaculum (p < 0.001), and peroneal tendon sheath (p < 0.001). Differences between the thickness of the anterior talofibular ligament and the calcaneofibular ligament (p < 0.001), the diameter of the fibular insertion of the anterior talofibular ligament (p < 0.001), the diameter of calcaneal attachment of the calcaneofibular ligament (p < 0.05), and tibiocalcaneal angle (p < 0.01) were statistically significant. The presence of the double fascicular anterior talofibular ligament and the calcaneofibular ligament fascicles correlate with connections to adjacent structures.

Does arthroscopic repair show superiority over open repair of lateral ankle ligament for chronic lateral ankle instability: a systematic review and meta-analysis

Background

There is still no definite consensus on whether arthroscopic repair shows superiority over open repair for chronic lateral ankle instability. We conducted a systematic review and meta-analysis of the current comparative studies to make a generalized analysis.

Methods

PubMed, Embase, and Web of Science databases were searched from inception to April 2020. Included studies were assessed by the level of evidence and quality of evidence (Cochrane Handbook or MINORS). The process of data extraction was conducted by two independent authors. The comparative results of clinical outcomes, stress radiographic outcomes, and complication rates between two groups were pooled. Statistical analysis was performed using STATA.

Results

Nine comparative studies for a total of 473 patients (250 arthroscopic repair, 223 open repair) were included. For the clinical outcomes, a significant difference was found in favor of arthroscopic repair with regard to AOFAS scores (MD 0.32, 95% CI 0.12 to 0.53, I² = 7.7%, P = .370) and VAS scores (MD − 0.30, 95% CI − 0.54 to − 0.05, I² = 48.3%, P = .102). No significant difference was found regarding to stress radiographic outcomes. Importantly, the total complication rate (RR 0.88, 95% CI 0.51 to 1.49, I² = 0%, P = .957) as well as nerve complication rate (RR 1.21, 95% CI 0.53 to 2.75, I² = 0%, P = .975) of arthroscopic repair group is not significantly different to that of open repair group.

Conclusions

Arthroscopic repair for lateral ankle instability shows excellent clinical results comparable to open repair. Especially, arthroscopic repair might alleviate more pain due to the minimally invasive procedure. Patients receiving arthroscopic repair do not result in a higher total complication rate and nerve injury rate.

Morphology of Anterior Talofibular Ligament After Arthroscopic Lateral Ankle Ligament Repair

BACKGROUND

Arthroscopic lateral ankle ligament repair for chronic lateral ankle instability (CLAI) yields good clinical results. However, the healing process of the ligament after anatomical repair remains unclear. This study evaluated the functional and patient-based outcomes for CLAI patients who underwent arthroscopic lateral ankle ligament repair and the morphological condition of the repaired anterior talofibular ligament (ATFL).

METHODS

We retrospectively reviewed 47 patients (50 ankles) who underwent arthroscopic lateral ankle ligament repair for CLAI (mean follow-up, 14 months). The Japanese Society for Surgery of the Foot Ankle-Hindfoot (JSSF) scale score and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) were assessed preoperatively and 12 months postoperatively. Magnetic resonance imaging (MRI) was performed preoperatively and at 6 and 12 months postoperatively to evaluate the ATFL. The functional and patient-based outcomes were compared between the group with repaired ATFLs and high signal intensity and the group with repaired ATFLs and low signal intensity.

RESULTS

The mean JSSF score improved significantly from 72.3 ± 11.6 preoperation to 95.3 ± 5.4 at 12 months postoperation. The MRI findings at 12 months postoperation showed that each repaired ATFL had a linear band structure from the talar to the fibular attachment site, and 41 of 50 ankles (82%) had low signal intensity of the ligament. On the SAFE-Q, the social functioning scores at 12 months postoperation were significantly higher in the low signal intensity group than in the high signal intensity group.

CONCLUSION

Arthroscopic lateral ankle ligament repair for CLAI yielded good functional and patient-based outcomes and restored the morphological condition of the ATFL.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

The role of the anterior talofibular ligament area as a morphological parameter of the chronic ankle sprain

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 mm² in the control group and 47.1 ± 10.4 mm² 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 mm², 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.

Absence of ATFL remnant does not affect the clinical outcomes of the modified broström operation for chronic ankle instability

PURPOSE

The modified Broström operation for chronic ankle instability has demonstrated good clinical results. Absence of ligamentous tissue is a risk factor for recurrence of ankle instability after surgery. This study evaluated the effect of quality of ligament tissue (anterior talofibular ligament, ATFL) on prognosis, in a cohort of patients with chronic ankle instability after the modified Broström operation.

METHODS

This was a retrospective case series. Overall, 60 patients underwent the modified Broström operation for chronic ankle instability (mean follow-up, 30.1 [range, 24-47] months). Presence of ATFL remnant was assessed on ultrasound, magnetic resonance imaging, and arthroscopy in all patients. Foot and ankle outcome score (FAOS) was used to evaluate functional outcomes. Clinical outcomes were compared by the condition of the ligament remnant. Association with other risk factors was evaluated using multiple linear regression analysis.

RESULTS

ATFL was visible in 51/60 cases on ultrasound. Thirty, 22, and eight patients had thin or absent; normal thickness; and thick ATFL on magnetic resonance imaging, respectively. ATFL was visible in 15 patients on arthroscopy and nonvisible or not clear in 45. No significant differences occurred in FAOS with the presence of ATFL remnant on ultrasound, arthroscopy, and the grade of ATFL thickness on magnetic resonance imaging. No correlation was found between FAOS and the thickness of ATFL.

CONCLUSION

The results suggest that the modified Broström operation for patients with chronic ankle instability was good, regardless of the presence or absence of ATFL remnant.

LEVEL OF EVIDENCE

III, Retrospective cohort study.

CT arthrography for demonstration of various articular injuries in post-sprained ankle pain

Background

Post-sprained ankles may sustain ligamentous tear, chondral defect, or osteochondral lesions (OCL). Being widely available and does not depend on high-end machine, the aim of this study was to assess the value of high resolution multi-detector CT arthrography (CTA) in detection of various ligamentous tears, chondral defects, and osteochondral lesions in case of sprain-related persistent ankle pain.

Results

There were 34 (68%) cases of ligamentous injury, most of which had single ligament affection whereas some cases demonstrated multi-ligamentous injury, and the total number of individual injured ligaments was 42 ligaments. There were 36 cases (72%) which had either chondral or osteochondral defects; the total number of OCL was 21 lesions and the total number of segmental cartilage defects was 20.

Conclusion

This study emphasized the diagnostic importance of multi-detector CTA in sprain-related ankle pain. In persistent post-sprained ankle pain, multi-detector CTA is a helpful imaging modality which could be utilized for detection of OCL, chondral defects, and various ligamentous tears.

Lower Signal Intensity of the Anterior Talofibular Ligament is Associated with a Higher Rate of Return to Sport After ATFL Repair for Chronic Lateral Ankle Instability

BACKGROUND

The treatment strategy for anterior talofibular ligament (ATFL) injury is usually determined by the ATFL remnant condition during surgery. Preoperative magnetic resonance imaging (MRI)-based signal intensity of the ATFL remnant, represented by the signal/noise ratio (SNR) value, can reveal the ATFL remnant condition. Thus far, there is a lack of evidence regarding the relationship between the ATFL remnant condition and functional outcomes.

PURPOSE/HYPOTHESIS

The purpose was to quantitatively evaluate whether the MRI-based ATFL ligament SNR value is related to functional outcomes after ATFL repair for ankles with chronic lateral ankle instability. The hypothesis was that a lower preoperative SNR is related to a better clinical outcome, particularly a higher rate of return to sport.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

First, a preliminary study was performed to measure the ATFL SNR in preoperative MRI, the results of which suggested that a preoperative SNR >10.4 was indicative of a poor ATFL condition. Then, a cohort study was retrospectively performed with consecutive patients who underwent open repair of ATFL injuries between January 2009 and August 2014. Accordingly, the patients were divided into 2 groups: high SNR (HSNR; ≥10.4) and low SNR (LSNR; <10.4). Functional outcomes based on the American Orthopaedic Foot and Ankle Society (AOFAS) score, Karlsson Ankle Functional Score (KAFS), and Tegner Activity Scale were then compared between the HSNR group and the LSNR group.

RESULTS

Ultimately, 70 patients were available for the final follow-up: 37 in the HSNR group and 33 in the LSNR group. No significant difference was detected between the HSNR group and the LSNR group in terms of the AOFAS score, KAFS, or Tegner Activity Scale (P > .05 for all) preoperatively. At the final follow-up, the mean ± SD AOFAS score in the LSNR group (92 ± 6) was higher than that in the HSNR group (87 ± 12), although no significant difference was detected postoperatively (P = .16). The mean KAFS in the LSNR group (94 ± 7) was significantly higher than that in the HSNR group (88 ± 11) postoperatively (P = .03). At follow-up, the mean Tegner score in the LSNR group (6; range, 3-7) was significantly higher than that in the HSNR group (5; range, 1-8) postoperatively (P = .03). Patients in the LSNR group had a significantly higher percentage of sports participation than those in the HSNR group (91% vs 65%, P = .02) postoperatively.

CONCLUSION

A lower signal intensity in the ATFL ligament based on preoperative MRI is associated with a better clinical outcome, particularly a higher rate of return to sport.

Ultrasound Characteristics of Foot and Ankle Structures in Healthy, Coper, and Chronically Unstable Ankles

OBJECTIVE

Ankle sprains constitute approximately 85% of all ankle injuries, and up to 70% of people experience residual symptoms. While the injury to ligaments is well understood, the potential role of other foot and ankle structures has not been explored. The objective was to characterize and compare selected ankle structures in participants with and without a history of lateral ankle sprain.

METHODS

A total of 71 participants were divided into 31 healthy, 20 coper, and 20 chronic ankle instability groups. Ultrasound images of the anterior talofibular and calcaneofibular ligaments, fibularis tendons and muscles, tibialis posterior, and Achilles tendon were obtained. Thickness, length, and cross-sectional areas were measured and compared among groups.

RESULTS

When under tension, the anterior talofibular ligament (ATFL) was longer in copers and chronic ankle instability groups compared to healthy participants (P < .001 and P = .001, respectively). The chronic ankle instability group had the thickest ATFL and calcaneofibular ligament among the 3 groups (p < 0.001). No significant differences (P > .05) in tendons and muscles were observed among the 3 groups.

CONCLUSIONS

The ultrasound protocol proved reliable and was used to evaluate the length, thickness, and cross-sectional areas of selected ankle structures. The length of the ATFL and the thickness of the ATFL and calcaneofibular ligament were longer and thicker in injured groups compared to healthy.

Similar Outcomes at Early Term After Arthroscopic or Open Repair of Chronic Ankle Instability: A Systematic Review and Meta-Analysis

Although the open modified Broström technique remains widely accepted as the gold standard for operative treatment of ankle instability, use of the arthroscopic repair technique has been rapidly increasing. Our aim is to conduct a comparative systematic review and meta-analysis of the data to determine whether there is a significant difference in clinical outcomes between arthroscopic and open repair for lateral ankle instability. A systematic literature review was performed using PubMed, Web of Science, the Cochrane Library, and EMBASE from 1980 to March 2018 to identify all English-language studies (level of evidence 1 to 3) comparing functional outcomes of arthroscopic versus open repair of lateral ankle instability. Four studies (1 level 1, 3 level 3) involving 207 patients met inclusion criteria. Of those, 97 participants were treated with arthroscopic repair, and 110 were treated with open repair. All of the subjective outcomes were improved for both groups across the 4 studies, without a significant difference in improvement between groups, except in 1 study, in which time to return to daily activity was significantly shorter in arthroscopic group (p < .05). Overall, this review demonstrated no statistically significant difference in outcome measures between arthroscopic versus open repair, both of which reported favorable and satisfactory outcomes, and produced equivalent clinical results. Additional randomized controlled studies of larger numbers of patients with longer follow-up times, however, are required to confirm whether arthroscopic repair leads to earlier recovery.

Imaging in Foot and Ankle Instability

This article reviews the imaging aspects relevant to ligamentous instabilities of the foot and ankle with a focus on MRI and ultrasound imaging. A pictorial review of the anatomy of the medial and lateral ankle ligaments, syndesmosis, spring ligament, Lisfranc complex, hallux sesamoid complex, and lesser toe plantar plate as seen on MRI is presented. Selected cases of ligamentous pathology relevant to foot and ankle instability are presented. The value of imaging in the assessment of foot and ankle instability is reviewed.

Differences Between Subtalar Instability and Lateral Ankle Instability Focusing on Subtalar Ligaments Based on Three Dimensional Isotropic Magnetic Resonance Imaging

OBJECTIVE

The purpose of this study was to assess the differences between subtalar instability (STI) and lateral ankle instability (LAI) focusing on subtalar ligaments using 3-dimensional (3D) isotropic magnetic resonance imaging (MRI).

METHODS

Preoperative MRIs of 10 patients with STI who failed nonoperative treatment and consequently underwent arthroscopic subtalar reconstruction were compared with preoperative MRIs of 23 patients with LAI who underwent ligament repair or reconstruction. Dimensions of anterior capsular ligament (ACL), interosseous talocalcaneal ligament (ITCL), calcaneofibular ligament (CFL), and anterior talofibular ligament (ATFL) were measured. Tears of ACL, ITCL, CFL, ATFL, cervical ligament, and inferior extensor retinaculum were analyzed.

RESULTS

Patients with subtalar instability had significantly lower ACL thickness and width than patients with LAI (thickness: 1.48 vs 2.12 mm, P = 0.045; width: 7.30 vs 8.64 mm, P = 0.029). An ACL thickness of 1.8 mm or less had sensitivity and specificity both at 75.0%, and an ACL width of 8 mm or less had sensitivity of 75.0% and specificity of 85.0% for discriminating STI from LAI. Absence or complete tear of ACL was more frequent in patients with STI than in patients with LAI (60.0% vs 13.0%, P = 0.010). The ATFL thickness was significantly greater in patients with LAI (P = 0.001). Complete tear of ATFL was more common in patients with LAI (P = 0.008). Complete tear of CFL was common in both the STI and LAI groups without significant difference (20.0% vs 21.7%). There was no significant difference in thickness and width of ITCL and in CFL thickness. Complete tear of ITCL, cervical ligament, and inferior extensor retinaculum were rare without significant difference.

CONCLUSION

In patients with STI, the ACL is thin and narrow and more commonly absent or torn compared with patients with LAI. Complete tear of ATFL was more common in patients with LAI. Complete tear of CFL was commonly encountered in both the STI and LAI groups.

Quantitative magnetic resonance imaging (MRI) analysis of anterior talofibular ligament in lateral chronic ankle instability ankles pre- and postoperatively

BACKGROUND

The aim of this study was to quantitatively evaluate and characterize the dimension and signal intensity of anterior talofibular ligament (ATFL) using 3.0 T MRI in the mechanical ankle instability group pre- and postoperatively.

METHODS

A total of 97 participants were recruited retrospectively in this study, including 56 with mechanical chronic ankle instability (CAI group) and 41 without ankle instability (Control group). All the subjects accepted MRI preoperatively. Among the 56 CAI patients, 25 patients, who accepted modified Broström repair of ATFL, underwent a MRI scan at follow-up. The ATFL dimension (length and width) and signal/noise ratio (SNR) were measured based on MRI images. The results of the MRI studies were then compared between groups.

RESULTS

The CAI group had a significantly higher ATFL length (p = 0.03) or ATFL width (p < 0.001) compared with the control group. The mean SNR value of the CAI group was significantly higher than that of the control group (p = 0.006). Furthermore, the mean SNR value of the ATFL after repair surgery (8.4 ± 2.4) was significantly lower than that of the ATFL before surgery (11.2 ± 3.4) (p < 0.001). However, no significant change of ATFL length or ATFL width were observed after repair surgery.

CONCLUSIONS

CAI ankles had a higher ATFL length or width as well as higher signal intensity compared with stable ankles. After repair surgery, the mean SNR value of the ATFL decreased, indicating the relaxed ATFL becomes tight postoperatively.

Magnetic Resonance Imaging and Stress Radiography in Chronic Lateral Ankle Instability

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.

A new classification of anterior talofibular ligament injuries based on ultrasonography findings

BACKGROUND

Ultrasonography (US) has become a useful tool in the evaluation of thickness and continuity of damaged ligaments owing to the rapid advances in its performance and availability. Furthermore, US examination is economical and can be undertaken in a more timely manner than MRI, as it can be performed during the first patient visit. It is also likely to be more accurate than the traditional method of palpating ligaments to diagnose possible injury. The anterior talofibular ligament (ATFL) is most frequently injured of the lateral ankle ligaments and easy to depict on US. This study aimed to assess the treatment outcomes of lateral ankle ligament injuries using a new classification for ATFL injuries based on US findings.

METHODS

A total of 140 acute lateral ankle ligament injuries in 132 patients (46 men, 86 women) treated non-operatively were evaluated retrospectively. The average age of the patients was 17.8 years (range, 7-57 years). Patients with a complaint of lateral ankle injury were examined using US, and the anterior talofibular ligament damage was classified into 5 types depending on the type of the injury. The treatment method was selected based on the ultrasonographic classification, and the clinical results were assessed by original evaluation and compared between treatment methods and classification types.

RESULTS

A Good or Excellent treatment result was obtained in 133 out of 140 injuries (95.0%). Significant differences were observed in the distribution of treatment methods by injury type (P < 0.001), and the distribution of outcomes was significantly different from the uniform distribution (P < 0.001). Our findings demonstrate that the ultrasonographic classification proposed in this study can be used to determine the appropriate treatment resulting in good outcomes for all types of anterior talofibular ligament damage.

CONCLUSION

Visualization of injured ligaments using US may introduce a novel approach of rating and treating ligament injuries.

Value of stress ultrasound for the diagnosis of chronic ankle instability compared to manual anterior drawer test, stress radiography, magnetic resonance imaging, and arthroscopy

PURPOSE

Clinicians frequently diagnose chronic ankle instability using the manual anterior drawer test and stress radiography. However, both examinations can yield incorrect results and do not reveal the extent of ankle instability. Stress ultrasound has been reported to be a new diagnostic tool for the diagnosis of chronic ankle instability. The purpose of this study was to assess the diagnostic value of stress ultrasound for chronic ankle instability compared to the manual anterior drawer test, stress radiography, magnetic resonance imaging (MRI), and arthroscopy.

METHODS

Twenty-eight consecutive patients who underwent ankle arthroscopy and subsequent modified Broström repair for treatment of chronic ankle instability were included. The arthroscopic findings were used as the reference standard. A standardized physical examination (manual anterior drawer test), stress radiography, MRI, and stress ultrasound were performed to assess the anterior talofibular ligament (ATFL) prior to operation. Ultrasound images were taken in the resting position and the maximal anterior drawer position.

RESULTS

Grade 3 lateral instability was verified arthroscopically in all 28 cases with a clinical diagnosis (100%). Twenty-two cases showed grade III instability on the manual anterior drawer test (78.6%). Twenty-four cases displayed anterior translation exceeding 5 mm on stress radiography (86%), and talar tilt angle exceeded 15° in three cases (11 %). Nineteen cases displayed a partial chronic tear (change in thickness or signal intensity), and nine cases displayed complete tear on MRI (100%). Lax and wavy ATFL was evident on stress ultrasound in all cases (100 %). The mean value of the ATFL length was 2.8 ± 0.3 cm for the stressed condition and 2.1 ± 0.2 cm for the resting condition (p < 0.001).

CONCLUSION

Stress ultrasound may be useful for the diagnosis of chronic ankle instability in addition to the manual anterior drawer test and stress radiography.

LEVEL OF EVIDENCE

III.

The anterior talofibular ligament: A detailed morphological study

The anterior talofibular ligament (ATFL) is commonly injured and may result in ankle instability. Good results from ATFL reconstruction have been reported; however complications and movement restrictions have also been observed. ATFL differences have been reported; however details of its precise bony attachment are lacking. This study provides a detailed morphology of the ATFL with respect to surgical and clinical applications. ATFL morphology, number of bands and the exact insertion points were studied in 50 formaldehyde embalmed feet. ATFL length was measured in different joint positions to assess its functional role: ATFL length varied from 18.81 mm in dorsiflexion to 21.06 mm in plantarflexion: mid-length width and thickness were 4.97 mm and 1.01 mm respectively. The bony attachment lengths were also measured: mean proximal and distal bony attachment lengths were 4.68 mm and 3.1mm respectively, while 13.04 mm had no bony attachment. One (22.9%), two (56.3%) and three (20.8%) band morphologies were observed originating 10.37 mm anterosuperior to the lateral malleolar tip and inserting 3.92 mm anterior to the anterior lateral malleolar line (ALML). Detailed morphology of the ATFL may help in restoring injured ATFL function by appropriate ligament reconstruction, as well as aid the understanding of the mechanism of ligament injury.

Reliability and Validity of Magnetic Resonance Imaging for the Evaluation of the Anterior Talofibular Ligament in Patients Undergoing Ankle Arthroscopy

PURPOSE

To analyze the reliability and validity of magnetic resonance imaging (MRI) for the detection of anterior talofibular ligament (ATFL) injuries in chronic lateral ankle instability by comparing its findings with arthroscopic findings.

METHODS

This diagnostic study enrolled patients who underwent MRI followed by subsequent arthroscopy for their various ankle disorders between April 2012 and February 2013. Two radiologists independently assessed the ATFL on MRI, and the results of their MRI assessments were then compared with the arthroscopic findings, which were used as the standard of reference.

RESULTS

On arthroscopy, 55 ATFL injuries were identified in 79 patients. The interobserver reliability of detecting ATFL injuries with MRI was excellent (intraclass correlation coefficient, 0.915). MRI, as interpreted by readers A and B, showed a sensitivity of 83.6% and 76.4%, respectively; specificity of 91.7% and 83.3%, respectively; negative predictive value of 71.0% and 60.6%, respectively; positive predictive value of 95.8% and 91.3%, respectively; and accuracy of 86.1% and 78.5%, respectively. According to the location of the ATFL injury, the sensitivity of MRI for readers A and B was 72.7% and 63.6%, respectively, at the fibular attachment site; 80.0% and 66.7%, respectively, at the talar attachment site; and 100% at the midsubstance and multiple sites. All false-negative diagnoses of ATFL injuries were observed at the fibular or talar attachment site (9 cases for reader A and 13 cases for reader B).

CONCLUSIONS

This study showed that MRI has excellent interobserver reliability (intraclass correlation coefficient, 0.915) for detecting ATFL injuries in patients in whom there is a clinical suspicion of chronic lateral ankle instability. The sensitivity and positive predictive value of MRI in the diagnosis of ATFL injuries were very high, whereas the sensitivity and negative predictive value of MRI were relatively low. According to the location of the ATFL injury, the sensitivities of MRI for the detection of ATFL injuries at the fibular or talar attachment site were lower than those at the midsubstance or multiple sites. In addition, all false-negative diagnoses of ATFL injuries were observed at the fibular or talar attachment site.

LEVEL OF EVIDENCE

Level III, diagnostic study of nonconsecutive patients (without consistently applied reference gold standard).

Increased ligament thickness in previously sprained ankles as measured by musculoskeletal ultrasound

CONTEXT

Lateral ankle sprains are among the most common injuries in sport, with the anterior talofibular ligament (ATFL) most susceptible to damage. Although we understand that after a sprain, scar tissue forms within the ligament, little is known about the morphologic changes in a ligament after injury.

OBJECTIVE

To examine whether morphologic differences exist in the thickness of the ATFL in healthy, coper, and unstable-ankle groups.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 80 National Collegiate Athletic Association Division I collegiate athletes (43 women, 37 men, age = 18.2 ± 1.1 years, height = 175.8 ± 11.1 cm, body mass = 75.0 ± 16.9 kg) participated in this study. They were categorized into the healthy, coper, or unstable group by history of ankle sprains and score on the Cumberland Ankle Instability Tool.

MAIN OUTCOME MEASURE(S)

A musculoskeletal sonographic image of the ATFL was obtained from each ankle. Thickness of the ATFL was measured at the midpoint of the ligament between the attachments on the lateral malleolus and talus.

RESULTS

A group-by-limb interaction was evident (P = .038). The ATFLs of the injured limb for the coper group (2.20 ± 0.47 mm) and the injured limb for the unstable group (2.28 ± 0.53 mm) were thicker than the ATFL of the "injured" limb of the healthy group (1.95 ± 0.29 mm) at P = .015 and P = .015, respectively. No differences were seen in the uninjured limbs among groups.

CONCLUSIONS

Because ATFL thicknesses of the healthy group's uninjured ankles were similar, we contend that lasting morphologic changes occurred in those with a previous injury to the ankle. Similar differences were seen between the injured limbs of the coper and unstable groups, so there must be another explanation for the sensations of instability and the reinjuries in the unstable group.

Proposal of a magnetic resonance technique for the evaluation of the calcaneofibular ligament minimizing false positive results

Background

Magnetic resonance (MR) techniques used to detect lesions of the ligament complex for articulation of the ankle lack the desired accuracy for the study of the calcaneofibular ligament (CFL). The lack of sensitivity of the conventional techniques is due to variations in the dimensions of the CFL. The best results are obtained when the image plane is oriented parallel to the ligament. This study aims to develop a model that addresses the width, length and angle parameters of the CFL and the orientation of the MR image plane, and thus determine a technique in the oblique transversal plane with the foot in anatomical flexion, that is adequate for the majority of patients.

Method

To determine this orientation and adapt it to the majority of people, images of the articulation of the ankle in the 3D isotropic, volumetric, sagittal plane of 100 volunteers were taken using the MR technique. None of the volunteers had a clinical history of ligament lesions, serious pathologies, or surgeries. A measurement of the length, width, and angle of the CFL relative to the sole of the foot was performed using the MR tools. A virtual model was developed that simulated the visualization of the CFL in the oblique transversal image plane from 35° to 45° using the CFL dimensions of 100 volunteers. The comparison of the simulations with the reconstructed images validated the model and permitted the calculation of the agreement and sensitivity of each technique in the detection of the complete CFL.

Results

Using the simulator, it was possible to obtain the limit angle for complete CFL visualization as a function of its dimensions for any angle of the oblique transversal image plane of the MR.

Conclusion

The results suggest that a single image acquisition technique in the oblique transversal plane at 38° with the foot in anatomical flexion would serve the majority of patients.

Isolated calcaneofibular ligament injury: a report of two cases

Injury to the lateral ankle ligaments is very common among both athletes and nonathletes alike. Although anterior talofibular ligament injuries and combination anterior talofibular ligament and calcaneofibular ligament injuries are considerably common, an isolated injury to the calcaneofibular ligament has rarely been reported. We present the case reports of 2 patients, both of whom had sustained an isolated calcaneofibular ligament injury. In both patients, the diagnosis was obtained from the clinical examination and magnetic resonance imaging. Also, in 1 patient, formal open surgical inspection was performed. We advocate conservative treatment initially using the same protocols used for common lateral ankle ligament injuries and, if necessary, surgical intervention to address this unique and rare pathologic entity.

Evaluation of anterior talofibular ligament injury with stress radiography, ultrasonography and MR imaging

OBJECTIVE

The purpose of this study was to clarify the efficacy of stress radiography (stress X-P), ultrasonography (US), and magnetic resonance (MR) imaging in the detection of the anterior talofibular ligament (ATFL) injury.

METHODS

Thirty-four patients with ankle sprain were involved. In all patients, Stress X-P, US, MR imaging, and arthroscopy were performed. The arthroscopic results were considered to be the gold standard. The imaging results were compared with the arthroscopic results, and the accuracy calculated.

RESULTS

Arthroscopic findings showed ATFL injury in 30 out of 34 cases. The diagnosis of ATFL injury with stress X-P, US, MR imaging were made with an accuracy of 67, 91 and 97%. US and MR imaging demonstrated the same location of the injury as arthroscopy in 63 and 93%.

CONCLUSION

We have clarified the diagnostic value of stress X-P, US, and MR imaging in diagnosis of ATFL injury. We obtained satisfactory results with US and MR imaging.