Rotational Instability after Anterior Talofibular and Calcaneofibular Ligament Section: The Experimental Basis for the Ankle Pivot Test

Comparison of Direct Repair Versus Anatomic Graft Reconstruction of the Anterior Talofibular Ligament: A Biomechanical Cadaveric Study

The goal of our study is to compare the stability of the anatomic reconstruction of the anterior talofibular ligament (ATFL) with direct repair of the ATFL, in a cadaver model. We performed the following techniques in 18 cadaveric ankles: the intact ATFL was cut, after which a direct repair using 2 anchors was performed. The repair was sectioned, and anatomic reconstruction was then performed with a tendon autograft. We measured angular displacement in 3 anatomic planes (axial, coronal, sagittal) for each situation in response to the anterior drawer test (ADT), talar tilt test (TTT) and pivot test (PT), using a specifically constructed arthrometer. The sectioned ATFL was inferior to the intact ATFL in the axial plane with the ADT (p = .012), in the axial plane with the PT (p = .001) and in the axial and coronal planes with the TTT (p = .013 and p = .016, respectively). Direct anatomic repair was inferior to the intact ATFL in the axial plane upon the PT (p = .009). No differences could be found between anatomic graft reconstructions and the intact ATFL with any manoeuver, nor when comparing anatomic graft reconstruction and direct repair with 2 anchors. We were able to conclude that anatomic graft reconstruction of the ATFL reproduces angular stability of the native ligament in a cadaver model. While we could not detect if anatomic graft reconstruction was superior to direct repair, the latter proved to be less stable in the axial plane upon internal rotation (pivot test) versus the intact ATFL.

Anatomy of the Ankle and Subtalar Joint Ligaments: What We Do Not Know About It?

Understanding of the ankle and subtalar joint ligaments is essential to recognize and manage foot and ankle disorders. The stability of both joints relies on the integrity of its ligaments. The ankle joint is stabilized by the lateral and medial ligamentous complexes while the subtalar joint is stabilized by its extrinsic and intrinsic ligaments. Most injuries to these ligaments are linked with ankle sprains. Inversion or eversion mechanics affect the ligamentous complexes. A profound knowledge of the ligament's anatomy allows orthopedic surgeons to further understand anatomic or nonanatomic reconstructions.

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.

Evaluation of the heel external rotation test in soft tissue deficiencies associated with adult acquired flatfoot deformity (AAFD). A cadaver sectioning analysis

BACKGROUND

To date, evaluation of the heel external rotation test has not been taken with respect to AAFD. Traditional 'gold standard' tests do not account for the contribution of the midfoot ligaments towards instability. These tests would be flawed as any midfoot instability may produce a false positive result.

AIMS

To evaluate the differential contribution of the spring, deltoid and other local ligaments in external rotation generated at the heel.

METHODS

Serial ligament sectioning was performed on 16 cadaveric specimens, with a 40 N-external rotation force applied to the heel. These were divided into four groups with different sequences of ligament sectioning. Measurements of the total amount/range of external, tibiotalar and subtalar rotation were made.

RESULTS

The deep component of the deltoid ligament (DD) was the main ligament influencing heel external rotation (P < 0.05, in all cases), and acted primarily at the tibiotalar joint (87.9 %). The spring ligament (SL) influenced heel external rotation predominantly (91.2 %) at the subtalar joint (STJ). Greater than 20 degrees external rotation could only be achieved with DD sectioning. The interosseous (IO) and cervical (CL) ligaments did not significantly contribute to external rotation at either joint (P > 0.05).

CONCLUSION

Clinically relevant external rotation (>20 degrees) is solely attributable to DD failure in the presence of intact lateral ligaments (LL). This test may improve detection of DD instability and allow clinicians to subclassify patients with Stage 2 AAFD into those where DD may or may not be compromised.

Lack of Definition of Chronic Ankle Instability With Arthrometer-Assisted Ankle Joint Stress Testing: A Systematic Review of In Vivo Studies

Despite extensive research on ankle instability a consensual and clear objective definition for pathological mechanical lateral ankle instability is yet to be determined. This systematic review aimed to summarize current available arthrometric devices, measuring methods and lateral ankle laxity outcomes in patients with chronic ankle instability that underwent objective arthrometric stress measurement. Sixty-eight studies comprising a total of 3,235 ankles with chronic ankle instability were included. Studies reported a wide range of arthrometric devices, testing position and procedures, and measuring methods. For the anterior drawer test, the average mean differences between injured and uninjured ankles ranged from -0.9 to 4.1 mm, and total translation in the injured ankle from 3.2 to 21.0 mm. Most common pathological threshold was ≥4 mm or ≥10 mm unilaterally and ≥3 mm bilaterally. For the talar tilt test, the average mean differences between injured and uninjured ankles ranged from 0.0° to 8.0°, and total tilt from injured ankle from 3.3 to 60.2°. Most common pathological threshold was ≥ 10° unilaterally and ≥ 6° mm bilaterally. It was found high heterogeneity in the scientific literature regarding the arthrometric devices, use of concomitant imaging and measuring methods of arthrometer-assisted anterior drawer and talar tilt tests which led to variable laxity outcomes in individuals with chronic ankle instability. Future studies should focus on standardizing the testing and measuring methods for an objective definition of mechanical ankle instability.

Decreasing the Abnormal Internally Rotated Talus After Lateral Ankle Stabilization Surgery

Background

Increased internal rotation of the talus has been found in patients with mechanical ankle instability (MAI).

Purpose/Hypothesis

To evaluate and compare the talar rotation position before and after lateral ankle lateral stabilization surgery in patients with MAI. We hypothesized that the abnormal internal talus rotation in patients with MAI will decrease after surgery for ankle lateral instability and that there will be no significant difference in internal talus rotation between the ligament repair and reconstruction groups.

Study Design

Case-control study; Level of evidence, 3.

Methods

We retrospectively studied 56 patients with MAI who underwent ankle lateral stabilization surgery after arthroscopic evaluation (repair, 36 cases; reconstruction, 20 cases). Before and after the operation, magnetic resonance images of all the participants were reviewed. The rotated position of the talus was measured and calculated by the Malleolar Talus Index at the magnetic resonance axial plane.

Results

The internal rotation of the talus decreased significantly after ankle lateral stabilization surgery in patients with MAI as compared with before surgery (mean ± SD, 83.3° ± 3.3° vs 86.7° ± 3.9°; P < .01). However, there was no statistically significant difference between the ligament repair and reconstruction groups before or after the operation.

Conclusion

Abnormal internal rotation of the talus in patients with MAI was decreased after ankle lateral stabilization surgery.

Ankle and syndesmosis instability: consensus and controversies

Ankle sprains are mainly benign lesions, but if not well addressed can evolve into permanent disability. A non-treated lateral, syndesmotic or medial ankle instability can evolve into ankle osteoarthritis. For this reason, diagnosis and treatment of these entities is of extreme importance.In general, acute instabilities undergo conservative treatment, while chronic instabilities are better addressed with surgical treatment. It is important to identify which acute instabilities are better treated with early surgical treatment.Syndesmosis injuries are frequently overlooked and represent a cause for persistent pain in ankle sprains. Unstable syndesmotic lesions are always managed by surgery.Non-treated deltoid ligament ruptures can evolve into a progressive valgus deformity of the hindfoot, due to its links with the spring ligament complex. This concept would give new importance to the diagnosis and treatment of acute medial ligament lesions.Multi-ligament lesions are usually unstable and are better treated with early surgery. A high suspicion rate is required, especially for combined syndesmotic and medial lesions or lateral and medial lesions.Ankle arthroscopy is a powerful tool for both diagnostic and treatment purposes. It is becoming mandatory in the management of ankle instabilities and multiple arthroscopic lateral/syndesmotic/medial repair techniques are emerging. Cite this article: EFORT Open Rev 2021;6:420-431. DOI: 10.1302/2058-5241.6.210017.

Comparison of Arthroscopic Surgery Versus Open Surgical Repair of the Anterior Talofibular Ligament: A Retrospective Study of 80 Patients from a Single Center

Background

This retrospective study from a single center aimed to compare the safety and clinical outcomes of arthroscopic surgery vs open surgical repair of the anterior talofibular ligament (ATFL).

Material/Methods

We randomly divided 80 patients with ATFL injury divided into 2 groups: an open surgery group and an arthroscopic group. The operation time, intraoperative bleeding volume, and the postoperative recovery time of all patients were analyzed. The anterior displacement and talus tilt angle, the American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS), the Jersey Shore Science Fair (JSSF) ankle-hindfoot scale score, and the Karlsson Ankle Functional Score (KAFS) were compared at 6 months, 1 year, and 2 years after surgery. We collected data on the incidence of postoperative complications during follow-up. All significant results were supported with a P value.

Results

The operation time, intraoperative bleeding volume, and postoperative recovery time in the arthroscopic group were better than in the open group (P<0.05). The AOFAS, JSSF, and KAFS in the arthroscopic group were better than in the open group at 6 months after the operation (P<0.05). The AOFAS, JSSF, and KAFS scale scores were not significantly different between the 2 groups at 1 year and 2 years after the operation (P<0.05).

Conclusions

The findings from this retrospective study showed that the use of arthroscopic surgical repair of the ATFL is a safe minimally invasive technique with reduced blood loss and surgical duration and good clinical outcomes.

Prediction of suspicious ankle instability using the calcaneofibular ligament cross-sectional area

Background

An injured calcaneofibular ligament (CFL) is a major cause of ankle instability (AI). Previous research has demonstrated that the thickness of the calcaneofibular ligament (CFLT) is correlated with higher-grade sprains and ankle instability. However, inflammatory hypertrophy is distinct from ligament thickness; accordingly, we considered that the calcaneofibular ligament cross-sectional area (CFLCSA) as a potential morphological parameter to analyze inflammatory CFL. We hypothesized that the CFLCSA was a key morphologic parameter in AI diagnosis.

Methods

We gathered the CFL data of 26 AI patients and 25 control subjects who had undergone ankle magnetic resonance imaging (A-MRI), and it had revealed no evidence of AI. Ankle level T1-weighted coronal A-MRI images were acquired. Using our image analysis program (INFINITT PACS), we analyzed the CFLT and CFLCSA at the CFL on the A-MRI. The CFLCSA was measured as the whole ligament cross-sectional area of the CFL that was most hypertrophied in the transverse A-MR images. The CFLT was measured at the thickest level of CFL.

Results

The mean CFLT was 3.49±0.82 mm in the control group, and 4.82±0.76 mm in the AI group. The mean CFLCSA was 33.31±7.02 mm² in the control group, and 65.33±20.91 mm² in the AI group. The AI patients had significantly greater CFLT (P<0.001) and CFLCSA (P<0.001) than the control group participants. A receiver operating characteristic (ROC) curve analysis in the evaluation of the diagnostic tests showed that the optimal cut-off score of the CFLT was 4.06 mm, with 76.9% sensitivity, 76.0% specificity, and an area under the curve (AUC) of 0.89 (95% CI, 0.79-0.99). The optimal cut-off threshold of the CFLCSA was 43.85 mm², with 92.3% sensitivity, 92.0% specificity, and AUC of 0.94 (95% CI, 0.86-1.00).

Conclusions

Even though the CFLT and CFLCSA were both significantly associated with AI, the CFLCSA was a more sensitive diagnostic test.

Long-term functional outcomes of all-inside arthroscopic repair of anterior talofibular ligament avulsion fracture

BACKGROUND

The main purpose of this study was to describe the all-inside arthroscopic technique for repairing anterior talofibular ligament (ATFL) avulsion fractures at the attachment points of the fibula and talus, and to evaluate the functional outcomes during long-term follow-up.

METHODS

The data of 78 patients with ATFL avulsion fracture treated in our hospital from August 2013 to November 2016 were analyzed retrospectively. All patients underwent surgery. Patients were divided into two groups according to whether they had undergone all-inside arthroscopic treatment or open treatment. The American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson Ankle Functional Score (KAFS), Foot and Ankle Outcome Score (FAOS) and a 36-item Short Form Health Survey questionnaire (SF-36) were used to evaluate functional outcomes.

RESULTS

The postoperative follow-up period was 24-48 months. All patients reported subjective improvements to ankle stability without any nerve, blood vessel or tendon complications. At the final follow-up, there was no significant difference in the AOFAS, SF-36 or sport participation rate between the arthroscopic group and the open group; however, the KAFS and FAOS were significantly higher in the arthroscopic group than in the open group.

CONCLUSIONS

For ATFL avulsion fractures, the all-inside ankle arthroscopic procedure produced better outcomes than did the open procedure. The all-inside ankle arthroscopic procedure provides a minimally invasive technique with acceptable long-term functional outcomes.

Biomechanical study of autograft anatomic reconstruction in lateral ankle instability

INTRODUCTION

The purpose of this work is perform a biomechanical comparison of anatomic reconstruction of the anterior talofibular ligament (ATFL) with the intact ATFL.

MATERIALS AND METHODS

We studied 18 fresh cadaveric ankles with intact ATFL. Each specimen was clinically assessed with the anterior drawer (AD) and varus tilt (VT) tests and the angular movement in the three spatial planes (axial, coronal and sagittal) was measured with an arthrometer using a sensor located in the talus.

RESULTS

Statistically significant differences were found in the axial plane, between the intact ATFL versus the sectioned ATFL for AD test with p = 0.012, and for VT test with p = 0.013. Regarding the coronal plane, we also observed a statistically significant difference for VT test with p = 0.016. In the sagittal plane, there are no statistically significant differences in both maneuvers. No statistically significant differences were found when comparing the biomechanics of anatomic ligament reconstruction versus the intact ATFL.

CONCLUSION

Autograft anatomic reconstruction of the ATFL showed biomechanical properties similar to those of the native ATFL, at the zero moment in a cadaveric model.

Role of surgery in the management of lesions of the medial collateral ligament of the ankle

Medial ankle instability is likely underestimated. Three types of medial collateral ligament (MCL) lesion exist: isolated lesions, in case of valgus sprain in external rotation; lesions associated with chronic lateral instability, in case of rotational instability; and lesions associated with medial insufficiency and valgus flat-foot. Diagnostic confirmation and treatment of MCL lesions, isolated or associated with chronic lateral instability, by ligament suture is at present largely arthroscopic. Chronic MCL lesions with valgus flat-foot are probably irreversible: ligament reconstruction is unreliable, and bone surgery (osteotomy, fusion) is required.

Contact patterns in the ankle joint after lateral ligamentous injury during internal rotation: A computational study

Lateral ankle instability, resulting from the inability of ankle ligaments to heal after injury, is believed to cause a change in the articular contact mechanics that may promote cartilage degeneration. Considering that lateral ligaments' insufficiency has been related to rotational instability of the talus, and that few studies have addressed the contact mechanics under this condition, the aim of this work was to evaluate if a purely rotational ankle instability could cause non-physiological changes in contact pressures in the ankle joint cartilages using the finite element method. A finite element model of a healthy ankle joint, including bones, cartilages and nine ligaments, was developed. Pure internal talus rotations of 3.67°, 9.6° and 13.43°, measured experimentally for three ligamentous configurations, were applied. The ligamentous configurations consisted in a healthy condition, an injured condition in which the anterior talofibular ligament was cut, and an injured condition in which the anterior talofibular and calcaneofibular ligaments were cut. For all simulations, the contact areas and maximum contact pressures were evaluated for each cartilage. The results showed not only an increase of the maximum contact pressures in the ankle cartilages, but also novel contact regions at the anteromedial and posterolateral sections of the talar cartilage with increasing internal rotation. The anteromedial and posterolateral contact regions observed due to pathological internal rotations of the talus are a computational evidence that supports the link between a pure rotational instability and the pattern of pathological cartilaginous load seen in patients with long-term lateral chronic ankle instability.

Gravity stress tibiotalar laxity evaluation with a biomedical gyroscopes device - cadaver study with progressive sectioning of lateral ankle ligaments

Purpose

Despite the evidence on the role of gravity stress test to access the instability of other ankle injuries, there is limited literature regarding gravity stress on the lateral ankle ligament’s insufficiency. The objective of our study was to objectively measure the tibiotalar angular movement under gravity stress after progressive sectioning of the lateral ankle ligaments.

Methods

We performed sequential sectioning of the anterior talofibular (ATFL), calcaneofibular (CFL), and posterior talofibular ligaments (PTFL) in twelve ankle specimens. Under gravity stress, we measured the angular movement of the talus in relation to the tibia. The measuring device is based on a three-axis gyroscope and accelerometer.

Results

Comparing to the intact condition, the plantar flexion increased on average 1.78° (95% confidence interval [CI] 1.15;2.42), 5.13° (95%CI 3.10;7.16) and 8.63° (95%CI 6.05;11.22), the rotation increased by 1.00° (95 CI -0.51;2.51), 3.68° (95%CI 1.97;5.40) and 15.62° (95%CI 10.09;21.14), and the varus increased 2.89° (95% CI 1.39, 4.39), 8.12° (95% CI 5.16, 11.07) and 11.68° (95% CI 7.91, 15.46), after sectioning the ATFL, CFL, and PTFL, respectively. The overall changes were statistically significant.

Conclusions

There was a significant tibiotalar laxity after sectioning of lateral ankle ligaments when the foot position is influenced only by gravity. The tibiotalar angular displacement was significant when the CFL and PTFL were cut which suggests that the gravity test could be used to assess combined lateral ankle ligament injury. This evidence might be a step forward in the development of lateral ankle ligaments gravity stress tests.

Level of evidence

5 (cadaver study)

Varus talar tilt combined with an internal rotation pivot stress assesses the supination instability vector in lateral ankle ligaments' injury - cadaver study

BACKGROUND

The lack of consensus on the relevance of the varus talar tilt test (VTTT) might be due to the divergence between the insufficiency vector of lateral ankle instability and the direction of this clinical test. Our hypothesis is that the VTTT is more accurate to diagnose lateral ankle ligaments rupture when it's applied with a pre-positioning of the foot in internal rotation (IR).

METHODS

We compared, in 12 cadaver ankles, the varus opening during a classic VTTT with the same test starting in an IR pivot, using a new arthrometer.

RESULTS

The classic VTTT caused a 13° tilt after ATFL section and 23,8° after ATFL and CFL section. The application of a VTTT with an IR prepositioning caused a 21,2° tilt after ATFL section (p = 0,002) and 29,5° after ATFL and CFL section (p = 0,006).

CONCLUSION

The VTTT is better to identify lateral ankle ligaments' insufficiency when it's applied with a pre-positioning of the foot in internal rotation. The resulting vector is similar to the supination trauma.