Arthroscopic all-inside ATiFL's distal fascicle transfer for ATFL's superior fascicle reconstruction or biological augmentation of lateral ligament repair

Chronic lateral ankle instability using anterior tibiofibular ligament distal fascicle transfer augmentation repair: an anatomical, biomechanical, and histological study

Background: The transfer of the anterior tibiofibular ligament distal fascicle (ATiFL-DF) for the augmentation repair of the anterior talofibular ligament (ATFL) shows potential as a surgical technique. However, evidences on the benefits and disadvantages of this method in relation to ankle joint function are lacking. Purpose: This study aimed to provide comprehensive experimental data to validate the feasibility of ATiFL-DF transfer augmentation repair of the ATFL. Methods: This study included 50 embalmed ankle specimens to measure various morphological features, such as length, width, thickness, and angle, for evaluating similarities between the ATiFL-DF and ATFL. Furthermore, 24 fresh-frozen ankle specimens were examined for biomechanical testing of the ATiFL-DF transfer augmented repair of the ATFL. Finally, 12 pairs of ATiFL-DF and ATFL tissues from fresh-frozen ankle specimens were treated with gold chloride staining to analyze mechanoreceptor densities. Results: Anatomical studies found that the lengths and thicknesses of the ATFL and ATiFL-DF are similar. Biomechanical outcomes showed that performing ATiFL-DF transfer for ATFL repair can improve the stability of the talus and ankle joints. This is evident from the results of the anterior drawer, axial load, and ultimate failure load tests. However, performing ATiFL-DF transfer may compromise the stability of the distal tibiofibular joint, based on the Cotton and axial load tests at an external rotation of 5°. Analysis of the histological findings revealed that mechanoreceptor densities for four types of mechanoreceptors were comparable between the ATiFL-DF and ATFL groups. Conclusion: ATiFL-DF transfer is a viable method for augmenting ATFL repair. This technique helps to improve the stability of the talus and ankle joints while compensating for proprioception loss. Although ATiFL-DF transfer augmented repair of the ATFL may negatively affect the stability of the distal tibiofibular joint, this procedure can enhance the stability of the talus and ankle joints.

The Distal Fascicle of the Anterior Inferior Tibiofibular Ligament: A Potential Landmark for Lateral Ankle Ligament Reconstruction

BACKGROUND

A reliable landmark and precise distances from the ligament attachments are needed for lateral ankle stabilization surgery. The distal fascicle of the anterior inferior tibiofibular ligament (AITFL) has been used to locate the anterior talofibular ligament (ATFL) or calcaneofibular ligament (CFL) centers on the fibula. However, there is no anatomic study to validate the distal fascicle of the AITFL as a landmark of lateral ankle ligament stabilization, and more importantly, the exact distances from the ATFL or CFL attachments to the distal fascicle of the AITFL are unknown.

METHODS

Sixteen frozen cadaveric specimens (8 paired specimens) with no previous history of ankle injury were used in this study. Whether the distal fascicle of AITFL was present in each specimen was confirmed. Then, the distances from the most distal insertion of the AITFL's distal fascicle to the footprint centers of the ATFL and CFL on the fibula were measured. All measurements were performed by 2 observers, and the intraobserver and interobserver reliabilities were analyzed by intraclass correlation coefficients (ICCs).

RESULTS

The distal fascicle of the AITFL was found in all specimens (100%). The mean distance from the most distal insertion of the AITFL's distal fascicle to the footprint centers of the ATFL, CFL, and the intersection center of the 2 ligaments on the fibula was 6.0 to 7.1 mm, 11.5 to 13.2 mm, and 9.0 to 10.0 mm, respectively. Excellent interobserver and intraobserver agreement (all ICCs > 0.9, P < .01) was shown in the anatomic measurements of these distances.

CONCLUSION

In this cadaveric study, we found that the distal fascicle was a constant structure of the AITFL in the lateral ankle. The distances from the most distal insertion of the AITFL's distal fascicle to the ligamentous footprint centers were reliable and may be used to identify the origins of the ATFL and CFL for lateral ankle ligament reconstruction.

CLINICAL RELEVANCE

This anatomic study validates the AITFL's distal fascicle as a potential landmark and, more importantly, determines the range of distances from AITFL's distal fascicle to the attachment centers of lateral ankle ligaments by anatomic measurements. The data may be used to identify the ATFL and CFL for lateral ankle stabilization surgery and become particularly valuable for endoscopic or arthroscopic techniques.

Biomechanical Study of Arthroscopic All-Inside Anterior Talofibular Ligament Suture Augmentation Repair, Plus Suture Augmentation Repair and Anterior Tibiofibular Ligament's Distal Fascicle Transfer Augmentation Repair

Objective: To explore the biomechanical efficacy of arthroscopic all-inside anterior talofibular ligament (ATFL) suture augmentation repair, plus suture augmentation repair and anterior tibiofibular ligament-distal fascicle (ATiFL-DF) transfer augmentation repair, so as to provide a basis for the accurate selection of ATFL repair in clinical practice. Methods: Twenty-four (12 pairs) fresh frozen human cadaver ankle specimens were used. Six of the ankle specimens were set as the normal group, and the other 18 ankle specimens were used to establish ATFL injury models. The ATFL was then repaired using arthroscopic all-inside ATFL suture augmentation repair (suture augmentation group), plus suture augmentation repair (plus suture augmentation group) and ATiFL-DF transfer augmentation repair (biological augmentation group), respectively. After the repaired ATFL was separated, the ankle specimens were fixed on an electronic universal testing machine with a customized fixture for the tensile test, and the ultimate failure load (N) and stiffness (N/mm) of the ankle specimens were compared. Results: The ultimate failure load of the plus suture augmentation group (229.3 ± 66.7 N) was significantly higher than that in the normal group (148.2 ± 39.4 N, p = 0.045) and the biological augmentation group (131.3 ± 38.8 N, p = 0.013). There was no statistical difference in ultimate failure load between the suture augmentation group (167.2 ± 47.2 N), the normal group and the biological augmentation group. The stiffness of the plus suture augmentation group (26.2 ± 8.2 N/mm) was significantly higher than that in the normal group (12.1 ± 3.8 N/mm, p = 0.005) and the biological augmentation group (12.7 ± 5.2 N/mm, p = 0.007). The stiffness of the suture augmentation group (23.6 ± 7.0 N/mm) was significantly higher than that in the normal group (p = 0.024) and the biological augmentation group (p = 0.033). There was no statistical difference in stiffness between the plus suture augmentation group and the suture augmentation group, and no statistical difference in stiffness between the normal group and the biological augmentation group. Conclusions: The tensile strength and rigidity of plus suture augmentation repair were significantly better than those of normal ATFL, suture augmentation repair and ATiFL-DF transfer augmentation repair. Suture augmentation repair can obtain tensile strength similar to normal ATFL and ATiFL-DF transfer augmentation repair, and suture augmentation repair can obtain rigidity significantly better than normal ATFL and ATiFL-DF transfer augmentation repair. ATiFL-DF transfer augmentation repair can obtain tensile strength and rigidity similar to normal ATFL.

Clinical outcomes of anterior tibiofibular ligament's distal fascicle transfer versus ligament reconstruction with InternalBrace™ for chronic ankle instability patients

PURPOSE

Treatment of chronic ankle instability (CAI) for ankle sprain patients remains a challenge. If initial treatments fail, surgical stabilization techniques including ligament reconstruction should be performed. Anterior tibiofibular ligament (ATiFL) distal fascicle transfer for CAI was recently introduced. The goal of the study is to assess the 1-year clinical effectiveness of ATiFL's distal fascicle transfer versus ligament reconstruction with InternalBrace™ (Fa. Arthrex, Naples).

METHODS

Between October 2019 and February 2021, 25 patients (14 males and 11 females) scheduled for ligament reconstruction treatment of CAI were enrolled after propensity score matching. Twelve underwent ligament reconstruction with InternalBrace™ (InternalBrace™ group) and thirteen underwent ATiFL's distal fascicle transfer (ATiFL's distal fascicle transfer group). We recorded the American Orthopedic Foot & Ankle Society (AOFAS) score, Visual Analogue Scale (VAS), anterior drawer test grade, patient satisfaction and complications. All results of this study were retrospectively analyzed.

RESULTS

Statistically significant (p = 0.0251, independent-samples t test) differences in the AOFAS can be found between the ATiFL's distal fascicle transfer group and the InternalBrace™ group. No substantial changes in the VAS (p = 0.1778, independent-samples t test), patient satisfaction (p = 0.1800, independent-samples t test) and anterior drawer test grade (p = 0.9600, independent-samples t test) were found between the two groups. There was one patient with superficial wound infection and one patient with sural nerve injury in the InternalBrace™ group and ATiFL's distal fascicle transfer group, respectively.

CONCLUSION

This is the first study that assessed a cohort of CAI patients and suggests that the ATiFL's distal fascicle transfer operation has the potential to attain good-to-excellent clinical outcomes after 1-year recovery. The AOFAS scores were significantly higher for patients with ATiFL's distal fascicle transfer, indicating that this technique may be considered a viable option for both patients and their surgeon, while long-term outcomes should be investigated in the future.

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.

Ankle microinstability: arthroscopic findings reveal four types of lesion to the anterior talofibular ligament's superior fascicle

PURPOSE

ATFL's superior fascicle injury has been considered to be the underlying cause in cases of ankle microinstability. As its clinical diagnosis can be difficult, arthroscopic examination may be the only objective diagnostic tool. The purpose of this study was to determine what types of injuries to the ATFL's superior fascicle are associated with ankle microinstability, and to provide the reader with an arthroscopic classification of the types of microinstability affecting the ankle.

METHODS

Ankle arthroscopy video records obtained during a four-year period from 232 patients with the diagnosis of ankle microinstability were reviewed. The characteristics of the ATFL's superior fascicle injury were identified, described and recorded along with any concomitant intra-articular pathology.

RESULTS

Four different injury patterns were consistently seen affecting the ATFL's superior fascicle. These ranged from ligament attenuation associated with loss of tension (type I), through to partial detachment (type II) or total detachment (type III) from the fibula. Finally, a total or partial resorption of the ATFL's superior fascicle (type IV) was also observed. There was a statistically significant association between the type of injury identified and the rate of intra-articular pathology observed arthroscopically. Equally, the higher the type in the classification, the higher the rate of loose bodies, lateral talar OCD, deltoid "open book" tears, and anterior soft-tissue formation.

CONCLUSION

Different types of ATFL's superior fascicle injury can be observed in patients with ankle microinstability, ranging from ligament attenuation associated with a loss of tension (8.2%) to different degrees of partial (69.1%) and total (16.8%) ligament detachment from the fibula, or ligament remnant resorption (5.9%). As the type of injury progresses along with the proposed classification, the rate of intra-articular injuries also increases. The clinical relevance of this study is that a morphological ATFL's superior fascicle tear is recognized in patients with the diagnosis of ankle microinstability.

LEVEL OF EVIDENCE

IV.

The lateral ankle ligaments are interconnected: the medial connecting fibres between the anterior talofibular, calcaneofibular and posterior talofibular ligaments

PURPOSE

A deep knowledge of lateral ankle ligaments is necessary to understand its function, pathophysiology and treatment options. The ankle lateral collateral ligament is formed by the anterior talofibular ligament (ATFL), the calcaneofibular (CFL) and the posterior talofibular ligament (PTFL). Although previous studies have reported connections between these ligaments on its lateral side, no studies have specifically assessed connections on the medial side. The aim of this study was to assess the morphology and consistency of the medial connections between the components of the lateral collateral ligament complex of the ankle.

METHODS

Forty fresh-frozen ankle specimens were dissected to look for connections between the three lateral ankle ligaments. After visualization of the lateral ligaments was achieved, the fibula was amputated and ligament insertions were released at the talar and calcaneal insertion points. Observation of the connections and video analysis of the dynamic relationships of ligament connections were performed.

RESULTS

Connections were found in all cases between the ATFL and PTFL, the ATFL and CFL, and the CFL and PTFL. Connections between ATFL and PTFL were not homogeneous. Although connections between the ATFLif and PTFL were noted in all cases (40), only 17 ankles (42.5%) had connections between the ATFLsf and PTFL. The amount of fibres of connection was also variable.

CONCLUSION

Connections between the three components of the lateral collateral ligament of the ankle may be observed from the medial aspect of the ankle, and this may have important implications for arthroscopic lateral ligament repair.

Arthroscopic all-inside ATFL and CFL repair is feasible and provides excellent results in patients with chronic ankle instability

PURPOSE

Chronic ankle instability has been described as presenting with complete tears of both the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) in 20% of cases. Arthroscopic techniques to treat chronic ankle instability are increasingly being reported and in some instances they can be technically demanding. The aim of this study was to describe an arthroscopic all-inside repair of both the ATFL and CFL, and to report the outcomes of a group of patients with chronic ankle instability that underwent the technique.

METHODS

Twenty-four patients [22 male and 2 female, median age 41 (range 22-56) years] with chronic ankle instability and torn ATFL and CFL were treated arthroscopically after failing non-operative management. Median follow-up was 35 (mean 34.7, and range 18-55) months. Through an arthroscopic all-inside technique, and using a suture passer and two knotless anchors, both fascicles of the ATFL and the CFL were repaired.

RESULTS

Arthroscopic examination demonstrated ATFL and CFL injuries in all patients. Subjective improvement in their ankle instability was observed postoperatively. The anterior drawer and the talar tilt tests were negative at follow-up. The median AOFAS score increased from 65 (mean 65, range 52-85) preoperatively to 97 (mean 97, range 85-100) at final follow-up.

CONCLUSION

Chronic ankle instability with concomitant injury of both the ATFL and CFL, can be successfully treated by an arthroscopic all-inside repair. The clinical relevance of the study is the description of the first arthroscopic all-inside ATFL and CFL anatomic repair technique, which offers excellent clinical results and the inherent benefits from minimally invasive surgery.

LEVEL OF EVIDENCE

IV, retrospective case series.