Deltoid ligament (DL) repair produced better results than DL nonrepair for the treatment for rotational ankle instability

Investigation into the effect of deltoid ligament injury on rotational ankle instability using a three-dimensional ankle finite element model

Background

Injury to the lateral collateral ligament of the ankle may cause ankle instability and, when combined with deltoid ligament (DL) injury, may lead to a more complex situation known as rotational ankle instability (RAI). It is unclear how DL rupture interferes with the mechanical function of an ankle joint with RAI.

Purpose

To study the influence of DL injury on the biomechanical function of the ankle joint.

Methods

A comprehensive finite element model of an ankle joint, incorporating detailed ligaments, was developed from MRI scans of an adult female. A range of ligament injury scenarios were simulated in the ankle joint model, which was then subjected to a static standing load of 300 N and a 1.5 Nm internal and external rotation torque. The analysis focused on comparing the distribution and peak values of von Mises stress in the articular cartilages of both the tibia and talus and measuring the talus rotation angle and contact area of the talocrural joint.

Results

The dimensions and location of insertion points of ligaments in the finite element ankle model were adopted from previous anatomical research and dissection studies. The anterior drawer distance in the finite element model was within 6.5% of the anatomical range, and the talus tilt angle was within 3% of anatomical results. During static standing, a combined rupture of the anterior talofibular ligament (ATFL) and anterior tibiotalar ligament (ATTL) generates new stress concentrations on the talus cartilage, which markedly increases the joint contact area and stress on the cartilage. During static standing with external rotation, the anterior talofibular ligament and anterior tibiotalar ligament ruptured the ankle's rotational angle by 21.8% compared to an intact joint. In contrast, static standing with internal rotation led to a similar increase in stress and a nearly 2.5 times increase in the talus rotational angle.

Conclusion

Injury to the DL altered the stress distribution in the tibiotalar joint and increased the talus rotation angle when subjected to a rotational torque, which may increase the risk of RAI. When treating RAI, it is essential to address not only multi-band DL injuries but also single-band deep DL injuries, especially those affecting the ATTL.

Arthroscopic repair of the tibiotalar fascicle of deltoid ligament is feasible through anterior ankle arthroscopy

PURPOSE

Although arthroscopic repair of the deltoid ligament is becoming a popular procedure, no studies have assessed which bundles of the deltoid ligament can be reached by anterior ankle arthroscopy. This study aimed to assess the feasibility of the arthroscopic repair of the deep layer of the deltoid ligament. In addition, it aimed to correlate which fascicle of the superficial layer of the deltoid ligament corresponds to the deep fascicle visualised by arthroscopy.

METHODS

Arthroscopy was performed in 12 fresh frozen ankles by two foot and ankle surgeons. With the arthroscope introduced through the anterolateral portal, the medial compartment and the deltoid ligament were explored in ankle dorsiflexion without distraction. Using a suture passer introduced percutaneously, the most posterior fibres of the deep deltoid ligament visualised by anterior arthroscopy were tagged. Then, the ankles were dissected to identify the deep and superficial bundles of the deltoid ligament tagged with a suture.

RESULTS

In all specimens (100%), the intermediate part of the tibiotalar fascicle, corresponding to the fibres originating from the anterior colliculus, was tagged with a suture. The posterior part of the tibiotalar fascicle was never tagged with a suture. In all specimens, the intermediate part of the tibiotalar fascicle grasped by the suture correlated with the tibiospring fascicle of the superficial layer.

CONCLUSIONS

The current study demonstrates the feasibility of the arthroscopic repair of the deep fascicle of the deltoid ligament. By performing anterior arthroscopy, it is possible to visualise and repair the intermediate part of the tibiotalar fascicle (deep layer of the deltoid ligament). These fibres correspond to the tibiospring fascicle of the superficial layer. The clinical relevance of the current study is that the arthroscopic repair of the deep layer of the deltoid ligament is feasible through anterior ankle arthroscopy.

LEVEL OF EVIDENCE

Not applicable.

Arthroscopic treatment of ankle multiligamentous injuries provides similar clinical outcomes to the treatment of isolated lateral ligament injury at the 2-year follow-up

PURPOSE

Rotational ankle instability is a multiligamentous injury defined as an overload injury of the deltoid ligament caused by a long-standing injury of the lateral collateral ligament in patients affected by chronic ankle instability. The purpose of the study was to compare the clinical outcomes of combined arthroscopic repair of lateral and medial ankle ligaments for rotational ankle instability versus isolated arthroscopic lateral ligament repair for lateral ankle instability at 2 years' follow-up.

METHODS

Between 2019 and 2021, 108 patients with chronic ankle instability were consecutively treated by arthroscopy. Of this group, 83 patients (77%) [median age: 26 (range, 14-77) years] underwent an isolated all-inside lateral ligament repair for lateral ankle instability (group A). In the remaining 25 patients (23%) [median age: 27 (range, 17-58) years], rotational ankle instability was clinically suspected and confirmed during arthroscopy; thus, a combined all-inside repair of lateral and medial ligaments was performed (group B). The same postoperative protocol was utilised for both groups. Patients were prospectively evaluated before surgery, at 3, 6, 12 and 24 months with Foot Functional Index (FFI) score, visual analogue scale (VAS) and Foot and Ankle Ability Measure-Sports subscale (FAAM-SS). At the latest follow-up, the satisfaction rate and complications were also recorded.

RESULTS

In both groups, FFI, VAS and FAAM-SS scores significantly improved compared to preoperative values (p < 0.001). In addition, according to all the scores evaluated, there was no significative difference (n.s) between groups at the final follow-up or at any of the intermediate follow-up. No major complications were observed in both groups.

CONCLUSIONS

Arthroscopic ligament repair in case of ankle multiligamentous injuries, such as in rotational ankle instability, provides excellent clinical outcomes and is comparable to isolated lateral ligament repair at 2 years' follow-up. Therefore, when treating ankle instability, arthroscopic repair of each and every ligament that appears injured provides the best potential outcomes and is the recommended treatment.

LEVEL OF EVIDENCE

Level II, prospective comparative.

Repair of deep deltoid ligament ruptures near the medial malleolar attachment or midsubstance rupture by using suture anchors into the talus combined with the transosseous suture in the medial malleolar

Purpose

For deep deltoid ligament ruptures near the medial malleolar attachment, anchors were usually placed at the posterior colliculus and intercollicular groove. However, this procedure usually requires a prolonged surgical incision to fully expose the deep deltoid ligament, causing more trauma. In order to reduce surgical trauma, we explored the treatment outcomes of suture anchor into the talus combined with transosseous suture in the medial malleolar for the treatment of deep deltoid ligament ruptures near the medial malleolar attachment or midsubstance rupture.

Patients and methods

This is a retrospective study of patients who received suture anchor into the talus combined with transosseous suture in the medial malleolar for repairing deltoid ligament ruptures near the medial malleolar attachment or midsubstance rupture. The outcome measures include the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), and the active range of motion (ROM) of the ankle at the final follow-up visit after surgery. Medial malleolus gap was evaluated by radiographic examination.

Results

This study included 64 patients. The mean follow-up time was 36.3 ± 15.2 months. There were 43 patients with injuries on the medial malleolar side, and 21 cases on the midsubstance. The average AOFAS and VAS were 87.5 ± 4.9 and 0.7 ± 0.5, respectively. No significance in medial malleolus gap between the contralateral side and affected side was observed.

Conclusion

For deltoid ligament ruptures near the medial malleolar attachment or midsubstance rupture, suture anchor into the talus combined with transosseous suture in the medial malleolar yields good clinical effect and outcome, is an optimal management of ankle syndesmosis injuries.