Diagnostic Value of Early Magnetic Resonance Imaging After Acute Lateral Ankle Injury

The Role of Ultrasound in the Management of Ankle Sprains and a Clinically Relevant Geisinger Ankle Sprain Sports Ultrasound Protocol

ABSTRACT

Ankle sprains are the most common lower extremity injury in physically active individuals. These injuries are classified as lateral, medial, and/or syndesmotic. Treatment may include functional rehabilitation, bracing, weight-bearing restriction, medications, injections, and surgery. While most sprains heal rapidly, permanent disability and pain may arise. Diagnostic ultrasound has been demonstrated to be accurate in diagnosing ligamentous injuries, but it is often excluded from management algorithms that rely on physical examination alone to diagnose significant injuries. This article proposes a comprehensive, evidence-based diagnostic ankle ultrasound protocol to implement in conjunction with thorough history and physical examination. We also review the current literature to describe where this protocol most improves diagnostic accuracy compared with physical examination alone.

Use of a comprehensive systemic ultrasound evaluation in the diagnosis and analysis of acute lateral region ankle sprain

BACKGROUND

For the diagnosis of acute lateral ankle sprain, many clinicians use ultrasound; they typically focus on the lateral ligament complex, which is the most common site of lesions in ankle sprain. However, this approach risks missing other foot and ankle lesions. The present study aimed to provide and analyze the results of a new ultrasound method of diagnosis for acute lateral ankle sprain which can thoroughly investigate overall lesions of the foot and ankle.

METHODS

Retrospective cross-sectional cohort study of 123 patients who underwent diagnostic ultrasound within 1 week of acute lateral ankle injury was performed. Causes of ankle sprain, incidence and severity of each ligament injury, location of anterior talofibular ligament (ATFL) injury, accompanying ligament injury, and occult fracture were analyzed.

RESULTS

Among the 102 cases of ATFL injuries, 60 (58.5%) had islolated ATFL injury, 28 (27.5%) had accompanying calcaneofibular ligament injury (CFL), and 14 (13.7%) had accompanying midtarsal or syndesmosis injury. ATFL injuries occurred on the fibula attachment in 48 (47.1%) cases, ligament mid-substance in 24 (23.5%) cases, and talus attachment in 30 (29.4%) cases. Among the 165 lesions from 123 cases, injuries of the fourth or fifth dorsal tarsometatarsal (12 cases, 7.3%), bifurcate (11 cases, 6.7%), and anterior tibiofibular (11 cases, 6.7%) ligaments were not rare.

CONCLUSION

These findings suggest that an ultrasound examination involving investigation of the midtarsal joint and syndesmotic ligament, as well as the ATFL and CFL, is useful for comprehensive, systemic diagnosis of acute lateral ankle sprain.

Acute Distal Rupture of the Calcaneus-Fibular Ligament Near the Calcaneus Insertion: Magnetic Resonance Imaging for Diagnostic Value and Comparison to Surgical Findings-A Retrospective Case Series Study

Distal rupture of the calcaneus-fibular ligament (CFL) was unique and important, because it is crucial to diagnose this type of injury before surgical intervention. In the present study, we collected several imaging characteristics based on MRI and tried to determine whether those clues can be used to diagnose distal rupture of CFL specifically and sensitively. Several imaging characteristics based on MRI were collected and used to diagnose and determine the location of CFL injury. All these clues on preoperative MRI were verified by operative findings and postoperative roentgenography. The interobserver agreement for the quality of the MRI images had a p value of .6 (McNemar test) and a Cohen's kappa of 65.2% (confidence interval, 50.5%-79.9%), and the agreement of the 2 observers was categorized as substantial. The sensitivity and specificity of distal rupture of CFL between 2 observers were 76.3%, 91.4% and 72.2%, 85.55%, respectively. The sensitivity and specificity of MRI clues were calculated as follows: hyperintense signal changes (86.1%, 38.6%), peroneal sheath fluid (63.9%, 74.7%), wave or laxity of the ligament (80.6%, 51.8%), fluid exudation around the ligament (80.6%, 51.8%), bone marrow edema on the calcaneus insertion (2.8%, 91.6%), avulsion fracture of the calcaneus (0%, 96.4%), incongruency or disruption of the ligament (69.4%, 77.1%), and exudation on the subtalar joint (52.8%, 71.1%). Preoperative MRI scans are a useful tool to diagnose distal injury of the CFL.

Fluoroscopic Evaluation of the Role of Syndesmotic Injury in Lateral Ankle Instability in a Cadaver Model

BACKGROUND

There is a high prevalence of concomitant lateral ankle ligament injuries and syndesmotic ligamentous injuries. However, it is unclear whether syndesmotic ligaments directly contribute toward the stability of the lateral ankle. Therefore, the aim of this study was to fluoroscopically evaluate the role of the syndesmotic ligaments in stabilizing the lateral ankle.

METHODS

Twenty-four cadaveric specimens were divided into 3 groups and fluoroscopically evaluated for lateral ankle stability with all syndesmotic and ankle ligaments intact and then following serial differential ligamentous transection. Group 1: (1) anterior talofibular ligament (ATFL), (2) calcaneofibular ligament (CFL), and (3) posterior talofibular ligament (PTFL). Group 2: (1) anterior inferior tibiofibular ligament (AITFL), (2) interosseous ligament (IOL), (3) posterior inferior tibiofibular ligament (PITFL), (4) ATFL, (5) CFL, and (6) PTFL. Group 3: (1) AITFL, (2) ATFL, (3) CFL, (4) IOL, (5) PTFL, and (6) PITFL. At each transection state, 3 loading conditions were used: (1) anterior drawer test performed using 50 and 80 N of direct force, (2) talar tilt <1.7 Nm torque, and (2) lateral clear space (LCS) <1.7 Nm torque. These measurements were in turn compared with those of the stressed intact ligamentous state. Wilcoxon rank-sum test was used to compare the findings of each ligamentous transection state to the intact state. A P value <.05 was considered statistically significant.

RESULTS

The lateral ankle remained stable after transection of all syndesmotic ligaments (AITFL, IOL, PITFL). However, after additional transection of the ATFL, the lateral ankle became unstable in varus and anterior drawer testing conditions (P values ranging from .036 to .012). Lateral ankle instability was also observed after transection of the ATFL and AITFL in varus and anterior drawer testing conditions (P values ranging from .036 to .012). Subsequent transection of the CFL and PTFL worsened the lateral ankle instability.

CONCLUSION

Our findings suggest that isolated syndesmosis disruption does not result in lateral ankle instability. However, the lateral ankle became unstable when the syndesmosis was injured along with ATFL disruption.

CLINICAL RELEVANCE

When combined with ATFL release, disruption of the syndesmosis appeared to destabilize the lateral ankle.

Isolated injuries to the lateral ankle ligaments have no direct effect on syndesmotic stability

PURPOSE

This study aim was to detect the impact of lateral ankle ligaments injury on syndesmotic laxity when evaluated arthroscopically in a cadaveric model. The null hypothesis was that lateral ankle ligament injury does not affect the stability of syndesmosis.

METHODS

Sixteen fresh-frozen above-knee amputated cadaveric specimens were divided into two groups of eight specimens that underwent arthroscopic evaluation of the distal tibiofibular joint. In both the groups, the assessment was first done with all syndesmotic and ankle ligaments intact. Thereafter, Group 1 underwent sequential transection of the three lateral ankle ligaments first to identify the effects of lateral ligament injury: (1) anterior talofibular ligament (ATFL), (2) calcaneofibular ligament (CFL), (3) posterior talofibular ligament (PTFL), then followed by the syndesmotic ligaments, (4) AITFL, (5) Interosseous ligament (IOL), and (6) PITFL. Group 2 underwent sequential transection of the (1) AITFL, (2) ATFL, (3) CFL, (4) IOL, (5) PTFL, and (6) PITFL, which represent the most commonly injured pattern in ankle sprain. In all scenarios, four loading conditions were considered under 100 N of direct force: (1) unstressed, (2) a lateral fibular hook test, (3) anterior to posterior (AP) fibular translation test, and (4) posterior to anterior (PA) fibular translation test. Distal tibiofibular coronal plane diastasis at the anterior and posterior third of syndesmosis, as well as AP and PA sagittal plane translation, were arthroscopically measured.

RESULTS

The distal tibiofibular joint remained stable after transection of all lateral ankle ligaments (ATFL, CFL, and PTFL) as well as the AITFL. However, after additional transection of the IOL, the syndesmosis became unstable in both the coronal and sagittal plane. Syndesmosis laxity in the coronal plane was also observed after transection of the ATFL, CFL, AITFL, and IOL. Subsequent transection of the PITFL precipitated syndesmosis laxity in the sagittal plane, as well.

CONCLUSIONS

The findings from the present study suggest that lateral ankle ligament injuries itself do not directly affect the stability of syndesmosis. However, if it combines with IOL injuries, even partial injuries cause syndesmotic laxity. As a clinical relevance, accurate diagnosis is the key for surgeons to determine syndesmosis fixation whether there is only AITFL injury or combined IOL injury in concomitant acute syndesmotic and lateral ligament injury.

A systematic review and meta-analysis on the value of the external rotation stress test under fluoroscopy to detect syndesmotic injuries

Purpose

Methods

Results

Conclusion

Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains Revision 2021

This revised clinical practice guideline (CPG) addresses the distinct but related lower extremity impairments of those with a first-time lateral ankle sprain (LAS) and those with chronic ankle instability (CAI). Depending on many factors, impairments may continue following injury. While most individuals experience resolution of symptoms, complaints of instability may continue and are defined as CAI. The aims of the revision were to provide a concise summary of the contemporary evidence since publication of the original guideline and to develop new recommendations or revise previously published recommendations to support evidence-based practice. J Orthop Sports Phys Ther 2021;51(4):CPG1-CPG80. doi:10.2519/jospt.2021.0302.

Diagnostic accuracy of clinical tests assessing ligamentous injury of the ankle syndesmosis: A systematic review with meta-analysis

OBJECTIVE

To summarise and evaluate research on the diagnostic accuracy of clinical tests for ligamentous injury of the ankle syndesmosis.

METHODS

CINAHL, Embase, and MEDLINE were searched from inception to February 12, 2021. Studies comparing clinical examination to arthroscopy, magnetic resonance imaging, or ultrasound were considered eligible. Meta-analysis was based on random effect modelling and limited to studies fulfilling all QUADAS-2 criteria. Sensitivity (SN), specificity (SP) and likelihood ratios determined diagnostic accuracy, all with 95% confidence intervals (CI).

RESULTS

Six studies were included (512 participants; 13 clinical tests; 29% median prevalence). No individual test was associated with both high sensitivity and high specificity. Tests with the highest sensitivity were: palpation [SN 92% (95%CI 79-98)] and dorsiflexion lunge [SN 75% (95% CI 64-84%); n = 2 studies]. Tests with the highest specificity were: squeeze test [SP 85% (95% CI 81-89%); n = 4 studies] and external rotation [SP 78% (95% CI 73-82%); n = 4 studies].

CONCLUSIONS

Clinical examination should involve initial clustering of tests with high sensitivity (palpation; dorsiflexion lunge), followed by a test with high specificity (squeeze). However, as these tests cannot definitively stratify syndesmotic injuries into stable vs unstable, decisions on optimal management (conservative vs surgery) require additional imaging or arthroscopy.

Increased ATFL-PTFL angle could be an indirect MRI sign in diagnosis of chronic ATFL injury

PURPOSE

Magnetic resonance imaging (MRI) has relatively low accuracy in diagnosing chronic anterior talofibular ligament (ATFL) injury. This study's purpose was to evaluate the angle between the ATFL and posterior talofibular ligament (PTFL) as a new indirect MRI sign of chronic ATFL injury in patients with mechanical ankle instability (MAI).

METHODS

This study included 200 participants: 105 patients with MAI and 95 patients seen at our institution for reasons unrelated to ankle instability. MR images of all 200 participants were reviewed. The ATFL-PTFL angle in the axial plane was measured and compared between groups. Receiver operating characteristic curves (ROC) were used to analyze ATFL-PTFL angles in participants with and without ATFL injury. The sensitivity and specificity of this method for diagnosing ATFL injury were calculated.

RESULTS

The mean ATFL-PTFL angle was significantly larger among MAI patients than among control patients (81.5° ± 9.8° vs 75.2° ± 8.9°, respectively; P < 0.01). The area under the ROC was 0.789 (P < 0.01). The optimal cut-off point for diagnosing ATFL injury on the basis of the ATFL-PTFL angle was 79.0° (sensitivity 0.89, specificity 0.67).

CONCLUSION

The ATFL-PTFL angle was significantly larger among MAI patients than among those without MAI. Increased ATFL-PTFL angle offers a new indirect MRI sign for diagnosing chronic ATFL injury. The ATFL-PTFL angle can be used not only to improve the accuracy of diagnosis of chronic ATFL injury, but also to evaluate the restoration of normal ankle joint geometry after lateral ligament reconstruction.

LEVEL OF EVIDENCE

III.