Deltoid Ligament Research Articles

Posterior tibial tendon dislocation after a medial ankle sprain: a case report

Medial ankle sprains have a very low incidence (5% of ankle ligament injuries), and most of the time, the first structure involved is the deltoid ligament complex. However, other structures, such as the spring ligament, posterior tibial tendon, and flexor retinaculum, can also get damaged. A 32-year-old man who had an ankle sprain while performing sports activities showed magnetic resonance imaging findings compatible with a detachment of the flexor retinaculum and medial dislocation of the posterior tibial tendon. Surgical intervention was suggested to this patient; deepening of the medial retromalleolar groove and reattaching of the retinaculum were performed. It is very important to consider this rare injury after a medial ankle sprain and to think out of the box, not always assuming a deltoid ligament lesion. Level of Evidence V; Therapeutic Studies; Expert Opinion.

The multi-ligament ankle fracture: Epidemiology, key anatomical findings and fixation strategies in unstable open injuries

BackgroundAnkle fracture surgery has traditionally focussed on restoration of bony anatomy, with fixation of the malleoli and syndesmotic stabilisation where applicable. However, high energy open fracture-dislocations can also result in periosteal stripping of the stabilising capsuloligamentous attachments. As such, restoration of osseous anatomy alone may not result in sufficient articular stability. ObjectivesIn this series from a level 1 trauma centre, we report a subset of highly unstable open ankle fractures with combined capsuloligamentous injuries, in which restoration of osseous anatomy did not result in a stable joint. Supplementary soft tissue reconstruction and other stabilisation techniques were required. MethodsRetrospective case series of eligible patients from a level 1 trauma centre. Inclusion criteria were open ankle fractures with tibial extrusion (AO 44) and persistent instability post-bony fixation, age over 18 years and non-diabetic. Analysis of injury pattern, mechanism, pathological anatomy, soft tissue and orthopaedic reconstruction methods was performed. Results16 patients were identified during the study period who met the eligibility criteria, out of 95 open ankle fractures treated between January 2017–December 2020. Most patients were under 65 (n = 13; 81.3%) and sustained combined or isolated injuries of the deltoid ligament, anterior capsule, lateral ligament complex (ATFL±CFL) and tibialis posterior retinaculum. The commonest injury pattern was tibial extrusion via a medial soft tissue defect with deltoid ligament and anteromedial capsule rupture. Associated syndesmotic instability and fixation was common (n = 10; 62.5%). Supplementary stabilisation methods to standard bony fixation included capsuloligamentous reconstruction or repair, “ORIF+” external fixation, or conversion to primary fusion or hindfoot nail. Six patients required either local or free flap soft tissue coverage. ConclusionsA subset of up to 20% of open ankle fractures require supplementary fixation beyond anatomical restoration of the bony anatomy due to persistent ligamentous instability. They are associated with capsuloligamentous and syndesmotic disruption, more commonly affecting the medial structures. These rare injuries can be defined as multi-ligament ankle fractures. Surgeons should be aware of this subset and be able to recognise where supplementary stabilisation strategies are required.

THE ROLE OF MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF TRAUMATIC INJURIES OF ANKLE JOINT

Background: Because of its wide array of advantages, MRI has gained popularity in evaluation of the musculoskeletal system. The advantages include non-invasiveness, lack of ionizing radiations, superior soft-tissue imaging and direct multiplanar imaging. Excellent visualization of cartilage, ligaments, tendons and bones can be achieved by the high resolution images of MRI. MRI can provide a comprehensive evaluation of ankle, including soft tissue and bone pathology. The soft tissue contrast resolution of MRI is superior to that of CT, and MRI is as good as or better than CT for most bone pathology. MRI is more sensitive than CT in the detection of stress fractures and trabecular bone injury.[4] Aim & Objective: 1.To study the normal anatomy of ankle joint on MRI.2 To assess acute traumatic injury patterns of ankle joint.3.To study the role of MRI in the evaluation of traumatic injuries of ankle joint..4 To study the chronic sequelae of ankle injuries. Methods: Study setting: Cross sectional study Tertiary care center. Study duration: 2 years ( from October 2019 to March 2021). Study population: The study population included all the cases with traumatic ankle injury referred to the Dept. of Radiodiagnosis our institute for MRI scan with or without X-ray ndings admitted at a tertiary care center such cases were included in the study. 50 Majority of cases found in 20-30 years age group 18( 36% Sample size: Results: ) followed by 40-50 group 12 cases (24%), 9 cases in 30-40, 7 cases in >50 and 4 cases in 10-20. Males contributing 34 (68%) and females 16 (32%). Deltoid ligament injuries are observed in 12 patients. However, isolated injuries are not seen. Deltoid ligament injuries are associated with bone, other ligamentous and tendon injuries. Anterior compartment tendon injuries were not observed in this study. 16 patients had a history of acute inversion injury. MRI plays an important role Conclusions: for planning further management and to decide whether the patient will require conservative or surgical management. Even though anatomical variants and technical artefacts can mimic a tear on MRI, it is still considered the primary imaging modality for optimal depiction of internal derangement in ankle injury. Common injuries observed in our study are - anterior talo- bular ligament injury, deltoid ligament injury, tenosynovitis, bone contusions and joint effusion.

Treatment of the Deltoid and Syndesmotic Ligaments in Chronic Ankle Instability

Historically, ankle instability research has focused primarily on the lateral ligament complex. However, more recently there has been an increased attention on the role of the deltoid ligament and syndesmosis in chronic ankle instability. We describe historical perspectives as well as the current state of evidence and techniques for a more comprehensive approach to ankle instability. Level of Evidence: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.

Study of Traumatic Ankle Injuries in Taif, Saudi Arabia, Using Magnetic Resonance Imaging

Background: Ankle injuries occur frequently and represent around 10% of all emergency department admissions. The preferred diagnostic modality for evaluating ankle injuries is Magnetic resonance imaging, because of its better soft tissue contrast; noninvasive imaging, as well as its scanning capability in several planes. Aims: This study aimed to highlight the importance of MRI in the assessment of patients with Ankle pain as a result of a traumatic injury in Taif, Saudi Arabia. Methods and materials: a retrospective study was carried out at King Abdulaziz Specialist Hospital in Taif, from October 2021 to February 2022. 56 traumatic patients were enrolled in the study. All images were evaluated by two expert radiologists. Results: Out of 56 patients; 31 (55%) were males and only 25 (45%) were females, the mean age was found to be 34. ± 12. Acute onset of pain was (82%) and (18%) was chronic. 44 (79%) of the respondents had joint effusion and 37 (66%) had ATFL Anterior Talofibular Ligament injuries. Regarding tendons injury, the most reported injury was tenosynovitis (14.3%). Deltoid ligament injury is significantly associated with age (P-value = .005), since those 35 years old or less are more frequently prone to have deltoid ligament injury (44%) than those more than 35 years old (9%). Conclusion: The MRI is the perfect modality of choice in the assessment of traumatic ankle injuries because it has higher sensitivity detection when compared to other modalities.

Two and three-dimensional CT mapping of the sustentacular fragment in intra-articular calcaneal fractures

The sustentaculum tali are tightly bound to the talus by the interosseous and deltoid ligament complex and have been considered a ‘‘constant fragment”. Yet there is a dearth of study on the anatomical patterns of the sustentacular segment. Consequently, this study is designated with the purpose of defining the prevalence and displacement of sustentacular fractures in intra-articular calcaneal fractures (ICFs) applying computed tomography (CT) mapping in both two-dimensional (2D) and three-dimensional (3D) conditions. From January 2019 to December 2020, the CT images of sixty-seven patients with eighty-one ICFs were retrospectively evaluated, besides, basic patient demographics and mechanisms of injury were documented. And the prevalence of sustentacular fractures was characterized in the sagittal or coronal CT planes. The subluxation, angulation, and translation of the portion of the sustentacular bone were noted. By decreasing rebuilt fracture fragments to suit a model of the sustentaculum tali, a 3D map was generated. Overall, the sustentacular fracture in 21 (25.9%) of the 81 ICFs, 15 (71.4%) were nondisplaced, 6 (28.6%) were displaced, and mean coronal angulation was 21.9°, and no comminuted. The relationship between sustentaculum tali and the talus was anatomically aligned in 71 (87.7%), and subluxation in 10 (12.3%). According to the research, 3D mapping demonstrated that most fracture lines start from the anterior of the sustentaculum tali, extending obliquely to the sulcus of the flexor halluces longus tendon. Moreover, this study provides a detailed description (displacement or articular dislocation) of the frequency of sustentacular fragments in ICFs. The finding disproves the ‘‘constant’’ theory of the sustentacular fragments, due to the fact that comminuted fracture of sustentaculum tali was rare. And the expertise of these fracture patterns may affect the progress of fixation concepts and surgical approaches. Moreover, we further speculated that the displacement of the sustentacular fragment was considerably more probable to emerge in the higher-order Sanders classification. Nevertheless, bigger sample size is required to further validate this position.

Isolated, periosteal stripping injuries of the Flexor Retinaculum: Case series of 3 patients with clinico-radiological review

Isolated periosteal avulsion injuries of the flexor retinaculum on the medial side of the ankle are rare and may mimic osseous injuries or deltoid ligament tears. We describe a case series of 3 individuals with isolated, stripping injuries of the tibial attachment of the flexor retinaculum without underlying fracture or deltoid ligament disruption. A new classification system of flexor retinaculum periosteal stripping injuries of the ankle is proposed with clinico-radiological features.

Role of the posterior deep deltoid ligament in ankle fracture stability: A biomechanical cadaver study

The deltoid ligament is a key component of ankle fracture stability. Clinical tests to assess deltoid ligament injury have low specificity. In supination external-rotation (SER) type-IV ankle fractures, there is either a medial malleolus fracture or deltoid ligament injury. These injuries are often considered unstable, requiring surgical stabilisation. We look to identify the anatomical basis for this instability. This study investigates the anatomical basis for such instability by re-creating SER type ankle fractures in a standardised cadaveric study model, investigating the anatomical basis for such instability. To investigate the anatomical basis for fracture instability in SER type ankle fractures. Four matched pairs of cadaveric limbs were tested for stability both when axially loaded and under external rotation stress. Four matched pairs of cadaveric limbs (8 specimens) were tested for stability when axially loaded to 750 N with a custom rig. Specimens were tested through increasing stages of SER injury in a stepwise fashion before restoring the lateral side with open reduction and internal fixation (ORIF). Clinical photographs and radiographs were recorded at each step. We defined instability in accordance with well accepted radiological parameters: > 4 mm medial clear space opening on a mortise-view radiograph or > 7 degrees of talar tilt. All specimens with an intact posterior deep deltoid ligament were stable. Once the posterior deep deltoid ligament was sectioned there was instability in all specimens. Stabilisation of the lateral side prevented talar shift, but not talar tilt. If the posterior deep deltoid ligament is intact then SER fractures can be managed without surgery. If the posterior deep deltoid is incompetent, ORIF and cautious rehabilitation is recommended because the talus can still tilt in the mortise.

Radiographic foot alignment and morphological features of deltoid ligament in pediatric patients with medial osteochondral lesions of the talus.

The cause of osteochondral lesions of the talus (OLT) in patients without a history of trauma remains unclear, and almost all nontraumatic lesions appear to involve the medial talar dome. This study aimed to investigate the relationship between foot alignment, deltoid morphology, and medial OLT in pediatric patients. In total, 28 patients (31 feet) with medial OLT (17 boys, 11 girls, mean age: 14.9 years), and 50 patients without OLT (50 feet, 31 boys, 19 girls, mean age: 14.5 years) were included in this study. The OLT patients were subdivided into traumatic and nontraumatic groups. Radiographic parameters of the foot arch were measured on weight-bearing lateral images. The extent of the OLT was measured on computed tomographic images. The ratio of deep deltoid attachment length of the talus to talar height was examined as deltoid ligament position index (DPI) on coronal magnetic resonance imaging. Nontraumatic medial lesions were frequently observed in pediatric patients (54.8%) compared to traumatic lesions. The depression of the foot arch was commonly identified in pediatric patients with resistant medial lesions. The lesion size was moderately correlated with DPI (rho = 0.48; P = 0.0086). The attachment of the deep deltoid ligament to the medial talar dome was located more proximally in nontraumatic lesions than in traumatic lesions and the control group. Our findings suggest that a combination of foot alignment and the anatomic variations in the attachment of the deep deltoid ligament contributes to the incidence of nontraumatic medial OLT in the pediatric population. Level of evidence: level IV.

A retrospective study of deltoid ligament repair versus syndesmotic fixation in lateral malleolus fracture combined with both deltoid ligament injury and inferior tibiofibular syndesmotic disruption.

To compare clinical outcomes of deltoid ligament repair versus syndesmotic fixation in lateral malleolus fracture combined with both deltoid ligament injury and inferior tibiofibular syndesmotic disruption. Patients diagnosed with lateral malleolus fracture combined with both deltoid ligament injury and inferior tibiofibular syndesmotic disruption who received open reduction and internal fixation (ORIF) were retrospectively reviewed. Seventy-eight patients were enrolled into the study, including 40 patients treated with lateral malleolus fracture ORIF and trans-syndesmotic fixation, and 38 patients treated with lateral malleolus fracture ORIF and deltoid ligament repair. Basic information and pre- and postoperative radiological materials were reviewed. Visual analog pain scale (VAS) score, Olerud-Molander score, and the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale were used for evaluating pain control and functional recovery postoperatively at different time points. No complication was reported in both groups. In the trans-syndesmotic fixation group, all patients received syndesmotic screw removal 6-8 weeks postoperatively. The Olerud-Molander score and AOFAS Ankle-Hindfoot Scale in the deltoid ligament repair group were higher than the trans-syndesmotic fixation group 3 months after operation. No statistical difference was found between the two groups in VAS score from 1 to 12 months postoperatively. Lateral malleolus fracture ORIF and deltoid ligament repair is an effective method for lateral malleolus fracture combined with both deltoid ligament injury and inferior tibiofibular syndesmotic disruption. Compared with trans-syndesmotic fixation, deltoid ligament repair holds the advantage of not needing surgical removal of inferior tibiofibular screws postoperatively.

Medial Ankle Instability: Review of Anatomy, Evaluation, and Treatment.

The medial ankle ligamentous complex, which includes the deltoid, talocalcaneal, and calcaneonavicular ligaments, functions to provide stability to the medial ankle. Injuries to the deltoid ligament can lead to medial-sided ankle pain, subsequent instability, and posttraumatic osteoarthritis given the altered biomechanics of the ankle joint. After completing a thorough physical examination, imaging modalities such as stress radiographs and magnetic resonance imaging can be used to confirm the diagnosis. Acute injuries to the deltoid ligament should be managed conservatively with a short course of immobilization. For patients with continued pain and instability following a regimen of nonoperative management, surgical intervention can be considered. Primary repair using suture anchor fixation to the medial malleolus can be utilized if sufficient tissue remains. However, if reconstruction is necessitated, autograft or allograft can be utilized in several described techniques.Levels of Evidence: Therapeutic.

Fracture of the lateral process of the talus with associated deltoid ligament injury: a report of 2 cases

BackgroundFractures of the lateral process of the talus (LTPF) are rare and only rarely are associated ligamentous injuries. The injury mechanism is commonly considered to be similar with ankle sprains, where excessive varus of the hindfoot leads to avulsion fractures of the lateral process of the talus. However, previous cadaveric studies have suggested that LTPF was more likely to be caused by eversion or external rotation force with dorsiflexion of the ankle. But no clinical evidence has been provided.Case presentationTwo patients presented to the emergency department with ankle pain after ankle eversion or external rotation. Physical examination revealed tenderness and swelling on both medial and lateral sides of the ankles. Plain radiographs and computed tomography revealed LTPF and medial soft tissue swelling, and magnetic resonance imaging confirmed a discontinuity of the deltoid ligament in Case 1. Surgical exploration revealed rupture of the superficial layer of the deltoid ligaments with intact deep layer in both patients. Treatment included fixation of the lateral process of the talus with headless compression screws and repair of deltoid ligaments. Both patients achieved excellent clinical outcomes 1 year post injury.ConclusionThere are many possibilities of the injury mechanism of LTPF. These two cases provided clinical evidence that eversion or external rotation force, in addition to inversion, was also an important mechanism of LTPF.

Biomechanical Changes in the Ankle Joint after Syndesmosis and Deltoid Injury and Subsequent Repair in a Cadaveric Model

Category: Ankle; Trauma Introduction/Purpose: Recent studies have stressed the important role of the deltoid ligament in maintaining global ankle stability. However, controversy remains around whether deltoid ligament repair is necessary in addition to syndesmotic repair when addressing injuries to both. The purpose of this study was to measure differences in tibiotalar joint contact pressures and tibiotalar contact area in the presence of deltoid ligament injury, syndesmotic injury, and after their respective repairs using a cadaveric model. Our hypotheses were 1) injury to the syndesmosis and deltoid would increase contact pressures and decrease contact area, 2) repaired injuries would restore biomechanics to near native state, and 3) that there would be similar tibiotalar contact pressures and contact area with syndesmosis repair alone compared to syndesmosis and deltoid ligament repair. Methods: Twelve human cadaveric lower extremities were randomized and tested under a series of conditions: 1) native, 2) sectioning of syndesmosis or deltoid, 3) sectioning of both the syndesmosis and deltoid, 4) repair of syndesmosis or deltoid, 5) repair of both. In one group, the syndesmosis was sectioned and repaired first and in the other the deltoid was sectioned and repaired first. The syndesmosis was repaired with a single high-tensile strength suture mechanism and deltoid ligament repairs were performed with a single suture anchor. Specimens were tested under each condition with an axial compressive and torsional load. Contact pressures and area within the ankle were measured with a digitized pressure sensor (Tekscan, Boston MA). Changes in contact pressure and area were compared with two-way repeated measure analysis of variance and significant findings were tested with post-hoc pairwise comparisons of estimated marginal means with Bonferroni-adjusted p-values for multiple comparisons (α = 0.05). Results: The highest mean contact pressure was seen when the deltoid was injured, but the syndesmosis was still intact (4.43 +/- 1.328 mPa) compared to mean contact pressure of 3.142 +/-0.511 mPa in the native condition. The lowest mean contact pressure was seen when the deltoid was repaired, but the syndesmosis was still disrupted (3.068 +/- 0.477). However, these differences in mean contact pressures did not differ significantly with pairwise comparison. Total contact area was significantly less following syndesmosis repair in isolation when compared to the native condition (609.55+-312.37mm2 vs 903.854mm2 p=0.0183). When the syndesmosis was repaired, irrespective of the state of the deltoid, the distribution of contact pressures shifted from the medial half of the joint to the lateral half of the joint in all but one specimen. Conversely, after deltoid ligament repair the distribution of pressure remain concentrated in the medial half of the joint, like the native state. Conclusion: We did not find a significant difference in overall mean ankle contact pressures between the various tested conditions. However, there can be a significant decrease in the joint contact area and a shift in the distribution of contact pressures within the joint after syndesmosis repair that was not seen after deltoid repair. In fact, with a deltoid repair alone, the distribution of contact pressures and the joint contact area did not differ significantly from the native state. These changes in contact area and distribution of pressures may affect long-term clinical and radiographic outcomes.

Incidence and Predictors of Valgus Tibiotalar Tilt after Progressive Collapsing Foot Deformity Reconstruction using Subtalar Fusion

Category: Ankle; Ankle Arthritis; Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Subtalar fusion is a powerful option for correcting hindfoot deformity in progressive collapsing foot deformity (PCFD). Despite successful correction through subtalar fusion, the development of valgus tibiotalar tilt at the ankle joint has been documented as a significant complication. This can be detrimental since abnormal forces on the ankle joint can induce cartilage wear and subsequent ankle arthritis over time. However, the incidence of valgus tilt of the ankle following subtalar fusion for PCFD reconstruction has not been extensively studied, and little is known about its etiological factors. The purpose of this study was to define the incidence of valgus tibiotalar tilt after subtalar fusion for PCFD reconstruction, and to determine if any demographic and radiographic parameters predict which patients develop this complication. Methods: This study reviewed 59 patients (median age: 59 years) who underwent PCFD reconstruction with subtalar fusion and had pre-and postoperative weightbearing anteroposterior radiographs of the ankle in the registry. Patients with a tibiotalar tilt prior to surgery were excluded. On standard weightbearing radiographs, the talonavicular coverage angle, talo-1st metatarsal angle, calcaneal pitch, and hindfoot moment arm (HMA), and medial distal tibial angle were measured. Weightbearing computed tomography (WBCT) was used to determine the presence of preoperative sinus tarsi or calcaneofibular bony impingement. A radiologist evaluated the superficial and deep deltoid ligaments using magnetic resonance imaging (MRI). Postoperative valgus tibiotalar tilt was defined as tilt >2 degrees. Univariate regression analysis was used to identify the factors associated with development of postoperative valgus tibiotalar tilt. These factors included age, gender, BMI, as well as concomitant procedures, radiographic parameters, lateral bony impingement on WBCT, and deltoid ligament status on MRI. Results: A total of 17 patients (28.8%) developed postoperative valgus tibiotalar tilt at a mean of 7.7 (range, 2-31) months. Eight (47.1%) of the 17 patients developed valgus tibiotalar tilt (mean talar tilt of 5.3 degrees, range: 4-8) on postoperative weightbearing within 3 months. In bivariate analysis, male gender and preoperative HMA were significantly associated with development of valgus tibiotalar tilt (Table 1). Univariate logistic regression demonstrated that preoperative HMA was associated with postoperative valgus tibiotalar tilt (odds ratio 1.06, P = .026), with a 6% increase in risk per millimeter of increased HMA. Deltoid ligament status on MRI and concomitant procedures on other joints including fusion did not correlate with postoperative valgus tibiotalar tilt. Conclusion: The incidence of valgus tibiotalar tilt after subtalar fusion in PCFD reconstruction was 28.8% in this study. Preoperative valgus hindfoot alignment rather than the condition of the deltoid ligament was a significant predictor of postoperative valgus tibiotalar tilt. Our findings indicate that surgeons should be cognizant of patients with a greater degree of hindfoot valgus and of their propensity to develop a valgus ankle deformity. Additionally, our relatively high incidence of valgus tibiotalar tilt suggests that weightbearing ankle radiographs should be included in the initial and subsequent follow-up of PCFD patients with hindfoot valgus treated with subtalar fusions.

Factors Related to the Inconstancy of Sustentaculum Tali Fragments in Intra-Articular Calcaneus Fractures

Category: Trauma Introduction/Purpose: Since intra-articular fractures are common in calcaneus fractures, anatomical reduction is important. Several ligaments such as spring ligament and deltoid ligament are attached to the Sustentaculum tali (ST). It is known that ST fragment is constant in calcaneus fracture. However, few studies have been reported to prove this. Therefore, we studied to establish criteria for the inconstancy of ST fragments through the analysis of computed tomography (CT) of the unaffected calcaneus, to confirm the prevalence of ST fragment inconstancy by applying these criteria, and to analyze the factors related to the inconstancy of the ST fragment. Methods: From 2012 to 2020, CT scans of calcaneus fractures of 122 patients (101 men and 21 women) were taken, and angulation and diastasis of ST fragment were measured in the semi-coronal plane. As a control, angulation and diastasis were measured in 62 unaffected calcaneus. After establishing criteria for the inconstancy of ST fragments, we evaluated the prevalence of ST fragment inconstancy. After, we analyzed related factors. Patient factors included age, BMI, smoking, and diabetes. Radiographic factors included the degree of comminution of the posterior facet, location of the outermost fracture line of the posterior facet, presence of an intra-articular fracture of the ST, and width of the ST fragment. Results: The upper limit of the 95% CI of angulation and diastasis was 7.58° and 2.51 mm, respectively. Based on these criteria, the inconstancy of the ST fragment was observed in 34.5%. The width of the ST fragment was significantly smaller in the inconstant group. Severe comminution of the posterior facet, intra-articular fracture of the ST, and diabetes were significantly higher in the inconstant group. The inconstancy of the ST fragment was significantly associated with the width of the ST fragment (p < 0.001) (Table 1). Cut-off values for the inconstancy of the ST fragment were 20.5 mm for the width of the ST fragment. Conclusion: In intra-articular calcaneal fractures, ST fragment inconstancy was observed in 34.5%. The width of the ST fragment was significantly associated with the inconstancy of the ST fragment.

Acute Deep Deltoid Ligament Reconstruction using a Novel, Arthroscopically-Assisted Technique: Case Report

Category: Arthroscopy; Ankle; Sports; Trauma Introduction/Purpose: The deltoid ligament complex is the main stabilizing structure of the ankle mortise and is often disrupted in rotational ankle injuries. Current treatment involves open techniques for the acute repair of the superficial deltoid layer, however, repair or reconstruction of the deep deltoid ligament (DDL) has proven to be challenging using open techniques. Our described arthroscopically-assisted technique allows for better intra-articular visualization and durable reconstruction of the ruptured DDL with suture and knotless bone anchors. The goal of this new, minimally invasive approach is to facilitate a faster and more reliable recovery and prevent long-term dysfunction and degeneration from medial and rotational ankle instability. We believe it has the potential to provide improved immediate ankle stability and decrease overall surgical morbidity compared to open treatments. Methods: Case of a 48-year-old male with ligamentous-equivalent Massioneuve fracture with medial clear space (MCS) measuring 11 millimeters. Arthroscopy revealed unstable syndesmosis and rupture of the DDL. After syndesmotic fixation, there was persistent MCS widening on stress exam. Arthroscopically-assisted DDL reconstruction was performed using an accessory anteromedial (AAM) portal between the tibialis anterior tendon and posterior tibial tendon. Needle localization identified the sagittal midpoint of the medial wall of the talus, inferior to articular cartilage. Anchor sites at both the medial talar wall and midportion of the distal medial malleolus (insertion and origin of the DDL, respectively) were then drilled via the AAM portal under arthroscopic and fluoroscopic guidance respectively at the isometric point. A suture anchor was placed into the talus and tails were loaded and secured to the medial malleolus with a bioabsorbable anchor. Ankle mortise was stable to stress exam and there were no restraints to physiologic motion. Results: The patient was kept non-weight bearing on his right lower extremity for a total of 6 weeks postoperatively and was seen in the clinic for routine follow-up visits at 2 weeks, 6 weeks, and 3 months post-procedure. Sutures were removed at 2 weeks, without any wound complications, and he was transitioned from splint to a short leg cast. He required only three days of oral narcotic analgesia. Weight-bearing in a controlled ankle motion (CAM) boot and physical therapy were both initiated at 6 weeks post-op. Radiographs at each follow-up visit were without abnormalities. At 3 months post-op, he was graduated from the CAM boot into a lace-up ankle brace, without any complaints of ankle pain or instability. The patient progressed well with full weight-bearing and physical therapy and was seen for a final visit at 5 months post-op with stable MCS. No complications were encountered. Conclusion: Acute DDL rupture is a common occurrence in ankle fractures and can be diagnosed radiographically and by arthroscopy. Known sequelae of untreated DDL disruption include medial instability and late valgus collapse. This case report demonstrates a novel, minimally invasive technique to successfully reconstruct the DDL, which may minimize the surgical morbidity compared to open dissection methods and allow for decreased recovery time postoperatively. This approach may also be utilized for cases of chronic instability. Future work includes larger case series with long-term follow-up and refinement of the technique as instrumentation advances.

Computational Modeling of Peritalar Joint Contact Mechanics in Flexible Flatfoot Deformity

Category: Hindfoot; Ankle; Ankle Arthritis Introduction/Purpose: Patients with longstanding progressive collapsing foot deformity (PCFD) often develop osteoarthritis of the peritalar (tibiotalar, subtalar, and talonavicular) joints, which can be symptomatic or can lead to fixed deformities that further complicate the treatment of other sequalae of the deformity (Mann, 1992). Degeneration and subsequent tearing of the arch supporting ligaments leads to altered joint contact mechanics which is a likely causative factor in the development of arthrosis (Hauser and Dolan, 2011). However, the initial effect of ligament tears on changes in joint contact mechanics in the collapsing foot has not been well characterized. The goal of this work was to compare the joint contact mechanics between the neutrally aligned and the flexible flatfoot (collapsed foot). Methods: A validated finite element model of the foot (Malakoutikhah et al., 2022a) was used to compare joint contact pressures between the normally aligned and the collapsed foot. The model of the foot constructed from CT scan images of a female cadaveric foot weighing 60 kg included all 28 bones, 72 ligaments, cartilage, and an encapsulating soft tissue. The model was loaded with 0.5 body weight applied at the center of mass and 0.25 body weight applied to the Achilles tendon simulating quiet stance. The collapsed foot model was created by simulated transection of the plantar fascia, long plantar, short plantar, deltoid, and spring ligaments and unloading of the posterior tibial tendon (Malakoutikhah et al., 2022b). The joint contact pressure maps were determined for both the neutrally aligned and collapsed foot models. The average and peak contact pressures were compared. Results: The peak contact pressures were increased in the tibiotalar and subtalar joints, but paradoxically were decreased in the talonavicular joint in the collapsed as compared to the neutrally aligned foot (Figure 1). The center of pressure was markedly different in all three joints between the neutral and collapsed foot conditions. Specifically, collapsing the foot caused two centers of the talonavicular joint peak pressure to shift towards the central region of the navicular bone, which were evenly distributed in the lateral and medial regions in the neutrally aligned foot. In the subtalar joint, the peak pressure that was uniformly distributed in the lateral and medial regions of the posterior facet in the neutrally aligned foot shifted towards the lateral region in the collapsed foot. Similarly, the peak contact pressure across the tibiotalar joint moved from the center to the lateral region when the foot collapsed. Conclusion: Degenerative tearing of the arch supporting ligaments in PCFD leads to an increase and laterization of the contact pressure in the tibiotalar and subtalar joints with a decrease of the pressure in the talonavicular joint. The paradoxical unloading of the talonavicular joint may be a result of the inability of the malaligned medial column to transmit force from the hindfoot to the forefoot. One implication of this work is that future treatments of PCFD might be directed towards normalizing contact pressure within the peritalar joints to prevent the progression of disease and the development of arthrosis.

Novel Dynamic Screw-Suture Stabilization System for Syndesmotic Repair Provides Better Anteroposterior Translation and Axial Tibiofibular Joint Stability: A Human Cadaveric Study

Category: Ankle; Basic Sciences/Biologics; Trauma Introduction/Purpose: The quest for optimal treatment of acute distal tibiofibular syndesmotic disruptions is still in full progress. Using suture-button repair devices is one of the dynamic stabilization options, however, they may not be always appropriate for stabilization of length-unstable syndesmotic injuries. Recently, a novel screw-suture repair system was developed to address such issues. The aim of this study was to investigate its performance in comparison to a suture-button stabilization of unstable syndesmotic injuries. Methods: Eight pairs of human cadaveric lower legs were CT scanned under 700 N single-leg axial loading in five foot positions - neutral, 15° external/internal rotation and 20° dorsi-/plantarflexion - in 3 different states: (1) pre-injured (intact); (2) injured, characterized by complete syndesmosis and deltoid ligaments cuts simulating pronation-eversion injury types III and IV as well as supination-eversion injury type IV according to Lauge-Hansen; (3) reconstructed, using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implants for syndesmotic stabilization, placed 20 mm proximal to the tibia plafond/joint surface. Following, all specimens were: (1) biomechanically tested over 5000 cycles under combined 1400 N axial and +-15° torsional loading; (2) rescanned. Clear space (diastasis), anterior tibiofibular distance, talar dome angle and fibular shortening were measured radiologically from CT scans. Anteroposterior, axial, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via motion tracking. Results: In each group clear space increased significantly after injury (p <= 0.004) and became significantly smaller in reconstructed compared with both pre-injured and injured states (p <= 0.041). In addition, after reconstruction it was significantly smaller in Group 1 compared to Group 2 (p < 0.001). Anteroposterior (AP) and axial movements were significantly smaller in Group 1 compared with Group 2 (p < 0.001, Figure). No further significant differences were identified/detected between the groups (p >= 0.113). Conclusion: Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw- suture reconstruction provides better anteroposterior translation and axial stability of the tibiofibular joint and maintains it over time under dynamic loading. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions.

Computed Tomography Changes Diagnosis, Management and Surgical Planning of Ankle Fractures

Category: Trauma; Ankle; Other Introduction/Purpose: Ankle fractures correspond to a substantial portion of traumatic injuries assisted in a primary health care unit. These fractures are usually promptly recognized by physical exams and conventional radiographs. Nevertheless, the number and pattern of the lesions and the identification of possible associated injuries still fail when using only these methods. CT scans have developed into an excellent instrument to analyze joint fractures in recent years. This study aims to compare ankle fracture assessment using CR in isolation with CT and CR in combination. This comparison will be performed considering diagnosis, lesions features, and treatment. We hypothesize that CT, in conjunction with CR, can significantly modify the diagnosis, therapeutics, and operative planning of ankle fractures when confronted with isolated CR. Methods: A total of 53 patients (mean age: 42 years, 15 - 75) diagnosed with an ankle fracture between 2011 and 2016, were assessed with CT and CR. Evaluations of the fractures using CR in isolation and CR combined with CT were compared using seven different readers. Fractures were assessed in terms of type, displacement, size, associated injuries, treatment, patient position, the implant of choice, and surgical planning considering the presence or absence of malleolar fractures and potential associated injuries. The concordance was measured for the own examiner's evaluations and between the examiners' assessments (intra-observer and inter-observer) by the Kappa coefficient. The results were determined by relative frequency distribution analysis (in percentage terms) and compared using a two-proportions test. Results: The Kappa index was higher than 0.75 for all interobserver and intra-observer reliabilities. Medial malleolus fractures characteristics (posteromedial fragment and anterior colliculus), the presence of posterior malleolus fracture and its characteristics (displacement, size, posteromedial or posterolateral segment) (ps<0.042), syndesmosis injury (p<0.001), and the absence of deltoid ligament lesion (p<0.001), were more evident with the combination of CT and radiographs. There was an increase in an operative indication (p=0.007), prone positioning (p=0.002), posterior malleolus surgical treatment (p<0.001), posterolateral approach for the lateral malleolus (p=0.003), and syndesmosis fixation (p=0.020) with the association of CT and CR, among all groups of expertise, with high inter-observer reliability (>0.75). Conclusion: Conventional radiographs may fail to demonstrate subtle and more complex lesions of the ankle joint, such as posterior and medial malleolus fractures, undermining its capability to determine the appropriate treatment plan. This study showed evidence that a CT scan, a widespread available exam, and the standard for the study of other articular fractures, increased the diagnostic capability in ankle fractures when used with radiographs. In addition, the combination of methods may improve the quality of the information received by the orthopedic surgeon, providing more details for a proper surgical or non- surgical treatment, positively affecting patient care.

MRI Findings in Patients with Discordant Results Between Gravity Test and Weight-Bearing Stress Views in Isolated Supination-External Rotation Fibular Fracture

Category: Trauma Introduction/Purpose: Medial and syndesmotic stability evaluation of isolated supination-external rotation fibula fractures (ISER) is critical to determine surgical conduct. However, there is no agreement on the best method to diagnose instability preoperatively. This problem is especially relevant in those with less than 2mm displacement in non-weightbearing radiographs. Different radiographic stress methods have been proposed: external rotation, weightbearing x-rays (WBx), and gravity stress radiographs (GSx). Likewise, the literature describes the use of ultrasound and magnetic resonance imaging (MRI) as complementary studies. To our knowledge, no studies have described the MRI findings in patients with discordant results between GSx and WBx views. Purpose: To analyze the imaging findings in WBx, GSx, and MRI in a consecutive group of patients with ISER with discordant results on stress views. Methods: For two years and prospectively, consecutive patients treated in a Level 1 trauma center were enrolled, performing the following imaging study protocol:- All patients with ISER fractures with a congruent tibiotalar joint on non-weightbearing radiographs underwent a bilateral WBx and GSx.- When there was a discordant result between WBx and GSx, MRI was taken. A retrospective analysis of the patients who had a complete study was carried out, considering the radiological findings and measurements. Measurements on radiographs were performed by six physicians (2 general practitioners, two trauma residents, and two ankle and foot subspecialists). One musculoskeletal radiologist analyzed the MRIs. The following parameters were measured, medial clear space (MCS), superior clear space (SCS), and tibiofibular clear space (TFCS). Inter-observer agreement in radiographs was analyzed using the intra-class correlation coefficient. Differences between groups were evaluated by t-student for independent samples, considering α <=5% significant. Results: Thirty-four patients were recruited. Interobserver agreement was good to excellent on all radiographic measurements. For all the measurements in the WBx, there were no significant differences between the injured and the healthy side. Average of MCS 2.51, SCS 3.07 and TFCS 3.74 mm for the uninjured side; and MCS 2.51, SCS 3.12, and TFCS 3.67 mm for the injured side. In the GSx, significant differences were observed for all measurements between the fractured and the healthy side. Average of MCS 3.55, SCS 3.85, and TFCS 3.89 for the healthy side; and MCS 5.87, SCS 4.25, and TFCS 4.44 for the injured side.100% of GSx and 0% of WBx met instability criteria (more than 2 mm compared to the healthy side). None of the MRIs showed a complete lesion of the deep deltoid ligament nor syndesmal complex. Conclusion: MRI did not demonstrate a complete deltoid nor syndesmal lesion in any patient with ISER fracture with normal WBx and altered GSx. A positive GSx does not correlate with MRI findings in patients with a non-displaced WBx study.