Diagnostic value of the posterior talofibular ligament area for chronic lateral ankle instability

An injured posterior talofibular ligament (PTFL) is one of the reasons for chronic lateral ankle instability (CLAI). Previous researches have demonstrated that the PTFL thickness (PTFLT) is associated with chronic ligament injuries. However, ligament hypertrophy is different from ligament thickness. Thus, we created the PTFL cross-sectional area (PTFLCSA) as a diagnostic image parameter to assess the hypertrophy of the whole PTFL. We assumed that the PTFLCSA is a key morphological diagnostic parameter in CLAI. PTFL data were obtained from 15 subjects with CLAI and from 16 normal individuals. The T1-weighted axial ankle-MR (A-MR) images were acquired at the level of PTFL. We measured the PTFLT and PTFLCSA at the posterior aspect of the ankle using our imaging analysis program. The PTFLT was measured as the thickness between point of anterior and posterior fiber of PTFL. The PTFLCSA was calculated as the whole cross-sectional PTFL area. The average PTFLT was 3.43 ± 0.52 mm in the healthy group and 4.89 ± 0.80 mm in the CLAI group. The mean PTFLCSA was 41.06 ± 12.18 mm 2 in the healthy group and 80.41 ± 19.14 mm 2 in the CLAI group. CLAI patients had significantly greater PTFLT ( P < .001) and PTFLCSA ( P < .001) than the healthy group. A receiver operating characteristic curve analysis demonstrated that the optimal cutoff score of the PTFLT was 4.19 mm, with 93.3% sensitivity, 93.7% specificity, and an area under the curve of 0.97. The most suitable cutoff value of the PTFLCSA was 61.15 mm 2 , with 93.3% sensitivity, 100% specificity, and area under the curve of 0.99. Even though the PTFLT and PTFLCSA were both significantly associated with CLAI, the PTFLCSA was a more exact morphological measurement parameter.

Approach to Ankle Instability in Patients With a Negative Ankle MRI: A Case Series

Objectives Injuries to the ankle ligaments are some of the most common musculoskeletal sports injuries. Ankle magnetic resonance imaging (MRI) is the standard diagnostic procedure in today's practice, but its reliability and validity remain controversial. The aim of this study was to explore the approach for patients with negative ankle MRI who continue to have symptoms of ankle instability despite conservative therapy. Methods A total of eight patients who were 14 years or older with negative ankle MRI who continue to have symptoms of ankle instability despite conservative therapy were admitted to our institution from January 1, 2015 to December 31, 2021. Results Eight patients with a mean age of 36, and a mean body mass index (BMI) of 37.7. All patients presented with ankle pain, locking, and giving way in variable severity. All the patients had a radiograph followed by an ankle MRI, which showed normal alignment of ankle joints without abnormality. Initially, all patients were treated conservatively but did not show any improvement. After that, they underwent an operation of lateral ankle ligament reconstruction by modified Brostrom technique, followed by casting and physiotherapy. The symptoms of ankle instability resolved in all patients. The ankle pain resolved completely in six patients, improved in one patient, and did not improve in one patient.  Conclusion Based on our results, we advocate reconstruction surgery by modified Brostrom technique for ligament repair in patients with clinical evidence of chronic ankle instability who have failed a trial of conservative management, even in the context of a normal ankle MRI.

A Rare Pattern of Ligamentous Injury of the Ankle: A Case Report and Review of the Literature

Ankle sprains are the most frequent sport related injuries with involvement of the lateral collateral ligament complex occurring in 85% of cases. Isolated anterior talofibular ligament injury is by far the commonest followed by combined anterior talofibular and calcaneofibular ligament strain. The posterior talofibular ligament is the strongest component of the lateral collateral ligament complex and is injured in severe ankle injury along with the other lateral collateral ligaments. While isolated calcaneofibular ligament strain has been reported, calcaneofibular ligament and posterior talofibular ligament strains with an intact anterior talofibular ligament are rare and reported in cadaveric studies. We present a case of radiologically diagnosed calcaneofibular ligament and posterior talofibular ligament injury and will discuss the anatomy, stress radiography, and magnetic resonance image findings and the mechanism of this particular injury.

Continuous and Connective Fibers of the Lateral Ankle Ligament Complex

The lateral ankle ligament complex (LALC) is an intricate structure; therefore precise anatomic knowledge is required by the surgeon. However, the structural relationship of the LALC remains unclear. Here, the features of the posterior talofibular ligament (PTFL) and the relationship to the LALC at the distal fibula were clarified in a cadaver study. The lengths of most of the anterior and posterior parts, and the widths of the anterior-posterior and superior-inferior parts, were measured with a digital caliper. In addition, the relationship between the anterior talofibular ligament (ATFL) and PTFL inside of the capsule is described. The small fiber bundles of the PTFL were manually divided, and the footprint of each bundle at the fibula and talus was clarified. The relationship between the ATFL and CFL, outside of the capsule, was examined on axial slices at the inferior fibula. The lengths of the most anterior and most posterior parts of the PTFL were 9.8 ± 1.7 and 29.4 ± 1.9 mm, respectively. The widths of the anterior-posterior and superior-inferior parts were 10.0 ± 0.9 and 5.8 ± 1.1 mm, respectively. Approximately 83% of the fibers between the ATFL and PTFL were continuous. The anterior-inferior fibers of the PTFL were continuous with the inferior fibers of the ATFL inside of the capsule. The ATFL and CFL converged with connective tissue from outside of the capsule at the distal fibula. The results of this study should prove useful to further clarify the relationships of the LALC both inside and outside of the capsule at the distal fibula.

Radiographic identification of the primary lateral ankle structures

BACKGROUND

Lateral ankle ligament injuries rank among the most frequently observed athletic injuries, requiring repair or reconstruction when indicated. However, there is a lack of quantitative data detailing the ligament attachment sites on standard radiographic views.

PURPOSE

To quantitatively describe the anatomic attachment sites of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL) on standard radiographic views with respect to reproducible osseous landmarks to assist with intraoperative and postoperative assessment of lateral ankle ligament repairs and reconstructions.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twelve nonpaired, fresh-frozen cadaveric foot and ankle specimens were dissected to identify the origins and insertions of the 3 primary lateral ankle ligaments. Ligament footprint centers were marked with 2-mm stainless steel spheres shallowly embedded at the level of the cortical bone prior to obtaining standard lateral and mortise radiographs. Measurements were performed twice by 2 blinded raters independently to calculate mean distances and assess reliability via intraclass correlation coefficients (ICCs).

RESULTS

Radiographic measurements demonstrated excellent reproducibility between raters (all interobserver ICCs>0.97) and across trials (all intraobserver ICCs>0.99). On the lateral view, the ATFL fibular attachment (mean±SD) was 8.4±1.8 mm proximal and anterior to the inferior tip of the lateral malleolus and attached on the talus 13.8±2.0 mm proximal and anterior to the apex of the lateral talar process. The CFL originated 5.0±1.4 mm superior and anterior to the inferior tip of the lateral malleolus and inserted on the calcaneus 18.5±4.6 mm posterior and superior to the posterior point of the peroneal tubercle. On the mortise view, the ATFL origin was 4.9±1.4 mm proximal to the inferior tip of the lateral malleolus and inserted on the talus 9.0±2.1 mm medial and superior of the apex of the lateral talar process and 18.9±3.1 mm inferior and slightly lateral to the superior lateral corner of the talar dome. The fibular CFL origin was 2.9±1.6 mm proximal and slightly medial to the inferior tip of the lateral malleolus and inserted on the calcaneus 18.0±5.1 mm distal to the apex of the lateral talar process.

CONCLUSION

Radiographic parameters quantitatively describing the anatomic origins and insertions of the lateral ankle ligaments were defined with excellent reproducibility and agreement between reviewers.

CLINICAL RELEVANCE

Quantitative radiographic anatomy data will assist in preoperative planning, improve intraoperative localization, and provide objective measures for postoperative assessment of anatomic repairs and reconstructions.