The distal margin of the lateral malleolus visible under ankle arthroscopy (articular tip) from the anteromedial portal, is separate from the ATFL attachment site of the fibula: A cadaver study

Ultrasound-Guided Anterior Talofibular Ligament Repair With Augmentation Can Restore Ankle Kinematics: A Cadaveric Biomechanical Study

Background:

Anterior talofibular ligament (ATFL) repair of the ankle is a common surgical procedure. Ultrasound (US)-guided anchor placement for ATFL repair can be performed anatomically and accurately. However, to our knowledge, no study has investigated ankle kinematics after US-guided ATFL repair.

Hypothesis:

US-guided ATFL repair with and without inferior extensor retinaculum (IER) augmentation will restore ankle kinematics.

Study Design:

Controlled laboratory study; Level of evidence, 4.

Methods:

A 6 degrees of freedom robotic testing system was used to apply multidirectional loads to fresh-frozen cadaveric ankles (N = 9). The following ankle states were evaluated: ATFL intact, ATFL deficient, combined ATFL repair and IER augmentation, and isolated US-guided ATFL repair. Three loading conditions (internal-external rotation torque, anterior-posterior load, and inversion-eversion torque) were applied at 4 ankle positions: 30° of plantarflexion, 15° of plantarflexion, 0° of plantarflexion, and 15° of dorsiflexion. The resulting kinematics were recorded and compared using a 1-way repeated-measures analysis of variance with the Benjamini-Hochberg test.

Results:

Anterior translation in response to an internal rotation torque significantly increased in the ATFL-deficient state compared with the ATFL-intact state at 30° and 15° of plantarflexion (P = .022 and .03, respectively). After the combined US-guided ATFL repair and augmentation, anterior translation was reduced significantly compared with the ATFL-deficient state at 30° and 15° of plantarflexion (P = .0012 and .005, respectively). Anterior translation was not significantly different for the isolated ATFL-repair state compared with the ATFL-deficient or ATFL-intact states at 30° and 15° of plantarflexion.

Conclusion:

Combined US-guided ATFL repair with augmentation of the IER reduced lateral ankle laxity due to ATFL deficiency. Isolated US-guided ATFL repair did not reduce laxity due to ATFL deficiency, nor did it increase instability compared with the intact ankle.

Clinical Relevance:

US-guided ATFL repair with IER augmentation is a minimally-invasive technique to reduce lateral ankle laxity due to ATFL deficiency. Isolated US-guided ATFL repair may be a viable option if accompanied by a period of immobilization.

Nonanatomic All-Inside Arthroscopic Anterior Talofibular Ligament Repair With a High-Position Anchor versus Anatomic Repair: An Analysis Based on 3D CT

BACKGROUND

In patients with chronic ankle instability, it is important to repair the anterior talofibular ligament (ATFL) at the anatomic origin site. However, there are limited reports on the clinical outcomes according to anatomic ATFL repair.

PURPOSE

To compare the clinical outcomes after arthroscopic ATFL repair according to whether the anchor is fixed at an anatomic position.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We performed a retrospective review of consecutive patients who underwent arthroscopic ATFL repair for chronic ankle instability and were available for a minimum 2-year follow-up. The patients were divided into 3 groups according to the anchor position at the distal fibula on 3-dimensional computed tomography: anatomic arthroscopic ATFL repair (anatomic group), subanatomic arthroscopic ATFL repair (subanatomic group), and nonanatomic arthroscopic ATFL repair (nonanatomic group). The visual analog scale for pain, Foot and Ankle Outcome Score (FAOS), and Karlsson ankle functional score were measured as subjective outcomes. Posturographic analysis and radiologic evaluation using stress radiographs and axial view magnetic resonance imaging were performed as objective outcomes.

RESULTS

Of 96 patients, 16 were excluded per the exclusion criteria, and 80 were evaluated (anatomic group, n = 24; subanatomic group, n = 42; nonanatomic group, n = 14). The mean age of the patients was 34.5 years, and the mean follow-up period was 27.4 months. A between-group comparison revealed significant differences in FAOS, Karlsson score, and fall risk evaluated by posturography at the final follow-up. Post hoc analysis revealed that the anatomic group had better clinical scores on the FAOS than did the nonanatomic group in all 5 domains (all P < .017). Patients in the anatomic and subanatomic groups had better Karlsson scores and fall risk than those in the nonanatomic group (P = .004 and P = .013, respectively). In terms of objective outcomes, patients in the anatomic and subanatomic groups had better outcomes in fall risk than did those in the nonanatomic group (both P = .001). There were no differences in clinical scores and objective outcomes between the anatomic and subanatomic groups.

CONCLUSION

Nonanatomic ATFL repair showed inferior outcomes when compared with anatomic ATFL repair. When arthroscopic ATFL repair is performed, the anchor should be fixed in the anatomic position to improve prognosis.

Sonographically Guided Anchor Placement in Anterior Talofibular Ligament Repair Is Anatomic and Accurate

Background

Arthroscopic repair is a widely accepted surgical treatment for chronic ankle instability; however, recent studies have shown that arthroscopic repair is nonanatomic in its anchor placement and resultant biomechanics. Ultrasound may improve the accuracy of the anchor placement.

Hypothesis

Our hypothesis was that the accuracy of anchor placement in sonographically guided anterior talofibular ligament (ATFL) repair will be comparable with that in open ATFL repair.

Study Design

Cohort study; Level of evidence, 3.

Methods

The study included 26 patients who received surgical treatment between April 2012 and October 2019 for chronic ankle instability. Fifteen patients underwent open modified Broström repair and 11 underwent sonographically guided ATFL repair. The distance between the anchor hole and the fibular obscure tubercle was measured using 3-dimensional computed tomography and was compared between the operative procedures. For comparison, a noninferiority trial was employed, with open modified Broström repair as the reference surgery. The noninferiority margin was defined as 5 mm.

Results

The mean ± SD distance between the anchor and fibular obscure tubercle was 6.0 ± 2.7 mm in open repair and 5.6 ± 3.3 mm in sonographically guided repair. The mean difference in distance between the techniques (open repair - sonographically guided repair) was 0.37 mm (95% CI, -2.1 to 2.9 mm). The lower margin of the confidence interval was within the noninferiority margin (-5 to 5 mm).

Conclusion

Anchor placement under sonographically guided ATFL repair was equivalent to that of open ATFL repair and can be considered anatomic and accurate.

Ultrasound-Guided Ankle Lateral Ligament Stabilization

PURPOSE OF REVIEW

Ultrasound (US) is an increasingly popular imaging modality currently used both in clinics and operating rooms. The purpose of this review is to appraise literature describing traditional lateral ankle stabilization techniques and discuss potential advantages of US-guided ankle lateral ligament stabilization. In addition, albeit limited, we will describe our experiences in perfecting this technique.

RECENT FINDINGS

To date, the modified open Broström-Gould technique remains as the gold standard surgical treatment for chronic ankle instability (CAI). In the past decade, modifications of this technique have been done, from a combination of arthroscopic and open procedure to an all-inside arthroscopic technique with a goal of minimizing wound complications, better outcomes, and earlier return to activity. Recently, the use of US as an adjunct to surgical procedures has gained popularity and several novel techniques have been described. The use of US in lateral ankle stabilization could allow accurate placement of the suture anchor at the anatomical attachment of the anterior talofibular ligament (ATFL) without iatrogenic damage to the neurovascular structures such as anterolateral malleolar artery, superficial peroneal nerve, and sural nerve. In summary, the use of US in ankle lateral ligament stabilization is a promising new micro-invasive technique. The theoretical advantages of US-guided ankle lateral ligament stabilization include direct visualization of desired anatomical landmarks and structures which could increase accuracy, decrease iatrogenic neurovascular damage, minimize wound complications, and improve outcomes.

Kinematics and Laxity of the Ankle Joint in Anatomic and Nonanatomic Anterior Talofibular Ligament Repair: A Biomechanical Cadaveric Study

BACKGROUND

Although it is crucial to accurately identify the anterior talofibular ligament (ATFL) attachment site, it may not be feasible to fully observe the ATFL attachment site during arthroscopic surgery. As a result, the repair position might often be an unintentionally nonanatomic ATFL attachment site.

HYPOTHESIS

Anatomic ATFL repair restores kinematics and laxity to the ankle joint, while nonanatomic ATFL repair does not.

STUDY DESIGN

Controlled laboratory study.

METHODS

Seven normal fresh-frozen human cadaveric ankles were used. The ankles were tested with a 6 degrees of freedom robotic system. The following ankle states were evaluated: intact, ATFL injured, ATFL anatomic repair, and ATFL nonanatomic repair. The ATFL nonanatomic repair position was set 8 mm proximal from the center of the ATFL attachment site of the fibula. For each state, a passive plantarflexion (PF)-dorsiflexion (DF) kinematics test and a multidirectional loading test (anterior forces, inversion moment, and internal rotation moment) were performed.

RESULTS

The kinematics and laxity of the anatomic repair were not significantly different from those of the intact state. In nonanatomic repair, the inversion-eversion angle showed significant inversion (3.0°-3.4°) from 5° to 15° of DF, and the internal rotation-external rotation angle showed significant internal rotation (2.0°) at neutral PF-DF versus the intact state. In addition, internal rotation laxity was significantly increased (5.5°-5.8°) relative to the intact state in the nonanatomic repair at 30° and 15° of PF. There were no significant differences in anterior-posterior translation between the repairs.

CONCLUSION

Although the anatomic ATFL repair state did not show significant differences in kinematics and laxity relative to the intact state, the nonanatomic ATFL repair state demonstrated significant inversion and internal rotation kinematics and internal rotation laxity when compared with the intact state.

CLINICAL RELEVANCE

Nonanatomic repair alters kinematics and laxity from the intact condition.