The incisura fibularis (IF) provides intrinsic stability to the ankle joint complex by interlocking the distal tibia and fibula. Despite a high frequency of ligamentous ankle injuries, scant attention has been given to the morphology of the IF morphology incisura fibularis in the onset and development of these lesions. Therefore, we systematically reviewed the relation between ligamentous ankle disorders and the morphometrics of the IF.

A systematic literature search was conducted on following databases: PubMed, Embase and Web of Science. Search terms consisted of ‘ankle trauma’, ‘ankle injury’, ‘ankle sprain’, ‘ankle fracture’, ‘tibiofibular’, ‘fibular notch’, ‘fibular incisura’, ‘incisura fibularis’, ‘morphometric analysis’, ‘ankle syndesmosis’, ‘syndesmotic stability’. The evaluation instrument developed by Hawker et al. was used to assess the quality of the selected studies. This protocol was performed according to the PRISMA guidelines and is registered on PROSPERO (CRD42021282862).

Nineteen studies were included and consisted of prospective cohort (n=1), retrospective comparative (n=10), and observational (n=8) study design. Comparative studies have found certain morphological characteristics in patients with ankle instability. Several studies (n=5) have correlated a shallow IF depth with a higher incidence of ankle injury. A significant difference has also been found concerning the incisura height and angle (n=3): a shorter incisura and more obtuse angle have been noted in patients with ankle sprains. The mean Hawker score was 28 out of 36 (range=24-31).

A shallower IF is associated with ligamentous ankle lesions and might be due to a lower osseous resistance against tibiofibular displacement. However, these results should be interpreted in light of moderate methodological quality and should always be correlated with clinical findings. Further prospective studies are needed to further assess the relation between the incisura morphometrics and ligamentous disorders of the ankle joint.

Keywords: ankle instability, ankle injury, incisura fibularis, fibular notch, tibiofibular morphometrics, ankle syndesmosis

Syndesmotic ankle injuries are present in one fourth of all ankle trauma and may lead to chronic syndesmotic instability as well as posttraumatic ankle osteoarthritis. The main challenge remains distinguishing them from other types of ankle trauma. Currently, the patient's injured and non-injured ankles are compared using plain radiographs to determine pathology. However, these try to quantify 3D displacement using 2D measurements techniques and it is unknown to what extent the 3D configuration of the normal ankle syndesmosis is symmetrical.

We aimed to assess the 3D symmetry of the normal ankle syndesmosis between the right and left side in a non- and weightbearing CT.

In this retrospective comparative cohort study, patients with a bilateral non-weightbearing CT (NWBCT; N=28; Mean age=44, SD=17.4) and weight-bearing CT (WBCT; N=33; Mean age=48 years; SD=16.3) were analyzed. Consecutive patients were included between January 2016 and December 2018 when having a bilateral non-weightbearing or weightbearing CT of the foot and ankle. Exclusion criteria were the presence of hindfoot pathology and age less than 18 years or greather than 75 years. CT images were segmented to obtain 3D models. Computer Aided Design (CAD) operations were used to fit the left ankle on top of the right ankle. The outermost point of the apex of the lateral malleolus (AML), anterior tubercle (ATF) and posterior tubercle (PTF) were computed. The difference in the coordinates attached to these anatomical landmarks of the left distal fibula in the ankle syndesmosis with respect to right were used to quantify symmetry. A Cartesian coordinate system was defined based on the tibia to obtain the direction of differences in all six degrees of freedom. Statistical analysis was performed using the Mann-Whitney U test to allow comparison between measurements from a NWBCT and WBCT. Reference values were determined for each 3D measurement in a NWBCT and WBCT based on their 2SD. The highest difference in translation could be detected in the anterior-posterior direction (Mean AP_NWBCT= −0.01mm; 2SD=3.43/Mean AP_WBCT=−0.1mm; 2SD=2.3) and amongst rotations in the external direction (Mean AP_NWBCT=−0.3°; 2SD=6.7/Mean AP_WBCT=-0,2°; 2SD=5.2). None of these differences were statistically significant in the normal ankle syndesmosis when obtained from a NWBCT compared to a WBCT (P>0.05).

This study provides references values concerning the 3D symmetry of the normal ankle syndesmosis in weightbearing and non-weightbearing CT-scans. These novel data contribute relevantly to previous 2D radiographic quantifications. In clinical practice they will aid in distinguishing if a patient with a syndesmotic ankle lesion differs from normal variance in syndesmotic ankle symmetry.

Purpose

to evaluate the radial displacement of meniscal allograft transplants (MATs) in patients operated with an open technique vs. an arthroscopic technique at 1 year postoperatively. Radial displacement or extrusion of the graft is frequently observed after meniscus transplantation. The hypothesis is that arthroscopically inserted MATs extrude less than open MATs and therefore have a more intra-articular position than open surgery transplants.

Purpose

To assess performance of a polyurethane scaffold designed to facilitate regrowth of tissue after irreparable partial meniscus tissue loss.

Purposes of the study

To assess the performance of an acellular synthetic scaffold in the treatment of painful partial meniscal tissue loss.

Introduction: Partial and total meniscectomy has been shown to result in cartilage degeneration and osteoarthritis in the long term. Thus, research efforts have focused on tissue regeneration following meniscectomy. A novel device has recently been developed which, when implanted in the meniscus, provides a three-dimensional honeycombed matrix for vascular ingrowth and tissue regeneration to replace lost meniscus tissue. To evaluate this vascular ingrowth and tissue regeneration a Dynamic contrast-enhanced MRI non invasive technique was used.

Methods: A prospective, non-randomised, single-arm, multi-centre, clinical investigation was conducted in 52 patients with an irreparable medial or lateral meniscal tear or partial meniscus loss, with intact rim. Patients were required to have a stable knee joint or be a candidate for knee joint stabilization within 12 weeks of the index procedure, have an International Cartilage Repair Society (ICRS) classification of Grade I or II, and have undergone no more than 3 previous surgeries on the index knee. Following implantation of the novel scaffold, dynamic contrast-enhanced magnetic resonance imaging (DCMRI) using intravenous gadolinium contrast material was performed at 1 week, and at 3 and 12 months post-implantation. Because the scaffold and normal meniscus tissue lack vascularity, the presence of signal enhancement in the device is an appropriate surrogate for the ingrowth of blood vessels and native tissue into the scaffold. All scans were assessed for neovascularization in the scaffold meniscus and integration of the implanted device. To date DCMRI scans at 3 months are available for 48 of the 52 patients. Full data for all available patients will be presented.

Results: Using this non-invasive technique evaluable DCMRI data at 3 months were obtained for 42 of the 48 patients (87.5%), showing vascularity, and therefore the presence of tissue, in 35 of the 48 (72.9%) patients. No enhancement (vascularity) was demonstrated in 6 of the 48 (12.5%) patients.

Conclusions: At 3 months post-implantation, vascularization, and therefore tissue ingrowth, was demonstrated using DCMRI in the vast majority of patients treated with the novel meniscus scaffold.